李朝义 929true 中国科学院上海生物化学研究所三室,上海原子核研究所二室 928true 中国科学院上海生物化学研究所东风生物化学试剂厂G-10生产小组 927true 中国科学院上海生物化学研究所代谢调节控制组 926true 郭尧君 925true 程伊洪 924true 鲁子贤 923true 中国科学院生物物理所电镜组 922true 中国科学院生物物理所电镜组 921true 上海生物化学所固相酶组 920true 奚国良,陈润莲,张鸿良,华家柽 919true 江寿平 918true 朱本明,徐伟军,熊立民 917true 王珩,甘人宝,刘定干,李载平 916true 刘蓉 915true 宋鸿镃,邱德仁 914true 毕汝昌,林政炯,高义贵 913true 林治焕,乌恩,孙珊,许桂珍,张克 912true 潘芝芳,杨庆有,季坤元 911true 许烨,钱绍祯 910true 黄天钧,陈立群,陆应钰,连少辉 909true 张友堃,王祁,杨太兴 908true 杨如圭,鞠彩娥 907true 上海生化所工厂 906true 徐伟 905true 孙炳荣 904true 聂玉生,沈恂 903true 李文琴,曹功杰,吴仁龙,祁国荣 902true 朱剑琴,李春宝,王新昌 901true 潘渌兴,丁昌荣,关启星 900true 胡世如,徐懋,纪极英,辛淑敏 899true 陈作义,朱本明 898true 崔淑文,陈必芳,张矩 897true 杨景文,叶国辉,钮择玲,章正廉 896true 卢善真,李良训,陈海宝 895true 方荣祥 894true 王培之,王贤舜,胡相钊,邹长康,张树中,盛海琳,张博林,倪元东,尚文学,徐占民 893true 季钟煜 892true 孙曼霁 891true 尤美莲,程秋琛 890true 王世绪,高才昌,刘铁英,吕织云 889true 莫汉庆,孙册 888true 郭长兴,王宏秀 887true 李刚,杜国光,聂松青 886true 刘朵花,张绍斌,史燕青 885true 齐义鹏,陈一平,雷克健 884true 冯慧,关雪辰,陈娥英,毕坎华,李小洁 883true 范培昌,王灵宝,毛一平,吴玲 882true 王智,李士谔,马金鉴 881true 刘金富,戎红梅,王妙珠,张孝勇 880true 曹功杰,李文琴,祁国荣 879true 王素云 878true 贺师鹏,魏莫愁 877true 雷克健 876true 毕汝昌,林政炯,高义贵 875true 陈采琴,樊蓉 874true 林波海 873true 吴伟雄,江寿平 872true 胡粹青,刘云娜,王苏民,林治焕 871true 陈采琴,樊蓉 870true 李竹芳,赵天睿,温博贵 869true 谢德贞,林应锐 868true 吴冠芸,方福德,杨善蓉 867true 戴培桦,钱力,徐有成 866true 魏西平,赵晜,程振起,赵林 865true 杨岐生 864true 蔡良琬,熊伟军 863true 袁振铎,任淑卿,杨宝华,余永光,李丽娟 862true 郑如玉,刘锦慧 861true 贺师鹏,葛韵琴,张孙曦,魏莫愁 860true 张国娣,俞鹤年,杨建平 859true 江虹 858true 王尧,杜子威,李斌,谈琪云,奚为乎 857true 吴同乐,张鸿卿 856true 李泂,王德全 855true 马丽英,梁殿权,王孝铭,李国忱,胡丽君 854true 秦德安,何学民,左大珏,鲁心安 853true 刘蓉 852true 韩澄源 851true 顾君华 850true 姚志建 849true 龚祖埙 848true 蒙义文,莫卫平,徐维政,陈素文 847true 喻梅辉,吴小兵,苑建青,窦强 846true 高思政,汤建平,张玮,程治平 845true 赵晜,吕俊宣,程振起,韩恒湘 844true 郭尧君 843true 龚祖埙,龚兴昌,郑巧兮 842true 郑秀龙,赵芳,高建国 841true 王锦兰,胡纫秋 840true 张向明 839true 杨高润 838true 胡匡祜,吴骋,李子孝 837true 李益新,方允中 836true 钱力,叶盛钰,徐有成 835true 董志伟 834true 袁振铎,余永光,任淑卿,李丽娟 833true 孙册 832true 薛绍白,柳惠图 831true 乐树云,江寿平,贾继萍 830true 卜明,方荣祥,莽克强 829true 叶济宇,李德耀,沈允钢 828true 吴玉薇,黄芬 827true 黄德培 826true 朱运松,顾银良,朱正美,顾天爵 825true 范培昌,单志芳,郭志勤 824true 李玉书,蔡翘 823true 琦祖和 822true 汪勇先,倪新伯,徐金龙 821true 李良训,王红英,汤洁,钱学军,薛金晨,卢善真,陈海宝 820true 李天荣,路苹,张林生,汪沛洪 819true 金绿松,毕杰梁,王文跃,金永福 818true 江丕栋 817true 康建,朱忠勇 816true 杨先和 815true 丁军凯,魏奉群 814true 许彩民,陈曦,潘华珍 813true 贺新军 812true 陈洪文,吴加金 811true 竺安 810true 谭瀞澜,林嘉友,邹明发,吴安然 809true 吴绳祖,吴雪,陆惠芬,杨颖 808true 戚德芳,潘铁城,曹功杰,祁国荣 807true 王年,何永山,蔡良琬 806true 黄芬,王苏民,鲁崎唔,吴玉薇,傅一工,张兰萍,傅广礼 805true 沈倍奋 804true 蔡玉奎 803true 陈建华,林元藻 802true 姚志建,马立人 801true 赵永芳,祝兵 800true 彭启明,李家芬,刘素媛 799true 谢正祥 798true 吴石君 797true 李宝硅,仲金良,彭宝珍,戴培桦,黄道培,卢惠卿,周国林 796true 陈世铭 795true 杨如圭,吴保生 794true 蒋传葵 793true 唐传业,郑集 792true 甘午君,温世鼎,褚建新,覃智,刘扬椅,叶淑琴 791true 杨振藩 790true 南国华,黄文长,熊丽萍 789true 张绍斌,常金珍 788true 俞鹤年,徐佐杰 787true 贺新军 786true 陈建华 785true 陈日新 784true 徐秀璋,王少芹 783true 季钟煜,黄均蓉 782true 郑玢,顾天爵,邱传禄 781true 周启玲,陈去恶 780true 姚志建,郭燕捷,陈邦本,马立人 779true 舒雨雁,洪息君,班建东,储开疆,汤圣希 778true 余敏忠 777true 何东明,陈农安 776true 陈石根,乐敏,王鹂形,毛嘉羚,黄祥贤 775true 林卓坤,李建平,林柅,张洪涛,刘以民 774true 徐友涵,倪基德 773true 顾学范,陈瑞冠,齐家仪 772true 郑文尧 771true 余曙华 770true 鄢家林,林进龙 769true 琦祖和,袁建刚,熊伟军,蔡良琬 768true 肖啸,程振起,赵晜,韩恒湘,王鄂生 767true 姚志建 766true 聂洪勇 765true 何宝俊,李忠民 764true 殷蔚薏,邵莉楣,赵军,白克智 763true 池旭生,庞大本 762true 汪和睦,鲁玉瓦 761true 赵保路,张建中 760true 刘国松,周佳音 759true 张志鸿 758true 蔡继炯 757true 袁建刚,黄秉仁,王丹平,蔡良琬 756true 陈泮藻,李振甲,陆菊明,潘长玉,韩春生 755true 秦德安,何学民,姚泽民 754true 李素文,薛绍白 753true 张廷逵 752true 邹国林,曹新文,朱汝璠 751true 董伟,沈定国,李新建 750true 潘华珍,李彩华,靳艳 749true 樊蓉,陈采琴 748true 李素文,薛绍白 747true 吴祥禔,周德义,梁熙南,魏琦 746true 齐义鹏 745true 初连瑞,孔祥英,谢绵光 744true 刘敬忠 743true 孙永泰,朱克莉 742true 孙玲 741true 褚红,景沛 740true 王苏生,舒群芳,周芬 739true 黄承汉,胡惠廉,袁恬莹 738true 沈珝琲,吴宁华,程小款 737true 朱珩 736true 张丰德,安祝平,岳慧琴,陈瑞阳 735true 宁国伯,曹文飞,翁志宏,郭明珠 734true 秦德安,何学民,姚泽民,黄琪 733true 吴宏,贺新军,周辉,王世真 732true 薛政国,陈世铭 731true 王家双 730true 吴晓生,李龙官 729true 司世麟,赵春桂,薛晓梅,张晶 728true 蒋立科,唐鑫生 727true 崔淑文,马东霞 726true 琦祖和,宋松,熊伟军 725true 徐友涵,宋錴毕 724true 郭燕捷,姚志建 723true 陈泮藻,李振甲 722true 邹国林,桂兴芬,钟晓凌,朱汝璠 721true 侯淦泉,汪志文,黄建明,向春,陈洪,汪江淮,陆松敏,王成英,郭素清,刘光海 720true 叶尚勉,刘光英 719true 李勇,郑武飞 718true 张林华,吴兆锋,刘秉文,蓝天鹤 717true 邹国林,曹新文,史平,朱汝璠 716true 蔡继炯 715true 蒋作君,沈一平 714true 蔡晓丹,王理开,徐晓利 713true 彭启明,张淑琴 712true 潘小平,蔡金莲,张炳海,王德岭 711true 袁进华 710true 李益新 709true 徐光,李茂深,沈慧芬,顾天爵 708true 吴蔚,宋晓国,丁玉珍 707true 张林华,刘秉文,吴兆锋,蓝天鹤 706true 罗喜牛,于志江,王新昌 705true 孙其坚,王翔,张少吾 704true 孙树杰 703true 韩澄源 702true 李家洋,李继耕 701true 王世成,崔浣华,吴日升,张之南,肖威,李德高 700true 王玉梅,王善莲,高子仪 699true 何东明,陈农安 698true 2^-_·体系，用鲁米诺作为指示O₂^-_·的化学发光剂，观察了不同浓度的NaOH、鲁米诺、pH、碱性二甲基亚砜加入量、测定时间及心绿染料对此法的影响。测定了山羊烟雾吸入伤后SOD活力和肺淋巴SOD清除量的变化。结果证明，本法灵敏度高、特异性强、操作简便、方法稳定，可快速、重复测定粗提取生物样品的SOD活力。]]> 赵琢道,黎鳌,杨宗城,董燕麟 697true 唐建清,邵国英,周丹宜,徐荣婷,陈诗书 696true 50为0.53μg，M olt-4细胞毒性试验IC为3.8×10^-10M与以前报道用改良Olsnes法所得结果相近。但操作简便、得率提高近5倍。]]> 贺永怀,刘演波,陈兴,沈倍奋 695true 田梦玉,张振强 694true 14C-鸟氨酸释放的 ¹⁴CO₂量测定鸟氨酸脱羧酶(ODC)的活性，酶反应在置于液闪计数瓶内的玻璃小管中进行，释放的 ¹⁴CO₂被瓶内滤纸片上的海胺吸收。实验结果表明，加酸释放 ¹⁴CO₂后30分钟 ¹⁴CO₂吸收已达最大值，且吸收量与释放量成正比，酶反应测定证明 ¹⁴CO₂释放速度在40分钟内保持恒定。ODC活性与酶浓度呈线性关系，此方法不仅用于ODC活性测定，而且亦可用于其他脱羧酶活性的测定。]]> 范慕贞,曹淑兰,马宇玲 693true 李爱群,李燕,莫简 692true 齐义鹏,黄永秀 691true 周泰生,徐森根 690true 吴加金 689true 朱圣庚,黄仪秀 688true 张向明 687true 阎有功,范纯武 686true 刘建华,王曼莹 685true 3H]地塞米松交换。实验结果表明，在此条件下，GCR活性不变，交换率达94.9±4.2%(皮质酮100_nM浓度下)，受体亲和力不变。本法适用于生理和病理条件下，特别是血浆糖皮质激素高浓度时的胞液GCR的检测。]]> 谭金兴,徐仁宝 684true 苗积生,吴吉勇,沈毅,黄利群,谈立松 683true 秦德安,钮晓达,陈跃春 682true 谢静平,黄芬 681true 章公大 680true 3-SPRIA)是一种新的放射免疫分析技术。本工作是用纯化的兔抗三碘甲腺原氨酸免疫球蛋白(T₃-IgG)，与聚苯乙烯小球偶联，制成T₃-固相抗体(T₃-SP-Ab)。T₃SPRIA方法简便、灵敏、快速和稳定。试验内、试验间及批间的变异系数分别为：11.6%、4.1%和5.4%。]]> 宋兰芝,华陵,严敏官 679true 吴直江,吴立丹,张懋弧 678true 范培昌,黄明,杨艳 677true 江鹏,蒋志伟,刘望夷 676true 薛晓珍,晏佩霞 675true 黄德培,傅庭治,朱春生,南轸,陆宗寰,宋贯交 674true 6μ／mg蛋白以上的国际临床标准。]]> 李成文,邵军石,吴本传,李红 673true 任洌,沈晶晶,陈晓穗,吕植 672true e计算机上运行。]]> 张懋弧,郭礼和 671true 杨先和 670true 韩刚毅 669true 6-甲基鸟嘌呤广泛应用于DNA损伤修复和肿瘤研究中。本文以巯基鸟嘌呤为原料经二步反应而制备。并对其进行了元素分析、紫外吸收光谱、高压液相色谱测定和同位素鉴定。]]> 王菊君 668true M氨水＝2：3：1(V／V)]可得到满意的层析谱。本法可用以鉴定PG(或GAG)中硫酸基位置及有关二糖的相对含量。]]> 张春玲,张英珊 667true 郭燕捷,陶陵,姚志建 666true 郭晓军,王申五,左瑾,韩日才,汪兆琦,吴冠芸 665true 聂崇兴 664true 李晋萍,P．Steffener 663true 9g。]]> 吴芝清,任向宇,王银定,姚文藻,甘露,王兴林,国纪石 662true 3)、甲状腺素(T₄)固相放射免疫联合测定法，是将₃抗体涂布在塑料小球上，将T₄抗体涂布在塑料管上。这种联合测定主要解决了T₃抗体对T₄的交叉反应。本法能在同一试管内进行，只需50μl血清样品，90分钟反应，可同时精确地测出两种激素水平，它比以往单独测定T₃或T₄的PEG双抗法更精确、快速和简便。]]> 连秉钩,张杰,王明华 661true 王耀萍,马星奇,王家槐 660true 吴震荣,刘文龙 659true 刘建成,周幼宝,孙国器,王明锁,冯纪辛 658true -10—19^-11mol。]]> 吴有光,龚十妹 657true I=a-b ln(B/T-r)+c ln²(B/T-r)+d ln³(B/T-r)将胰岛素放射免疫测定盒所测得的6个不同浓度胰岛素的T(cpm)及B(cpm),或B(k)/T(k)(％)(k=1,…,6)输入微机,运行事先编好的程序,即可定出参数a,b,c,d和r。如果使用同一测定盒测出了某些血清样品的百分率B/T(％),或直接将其B值和T值由微机键盘输入后,微机屏幕即回答出血清胰岛素浓度值I(μU/ml)。所得结果比常用的Logit曲线要精确得多。]]> 涂其栵,刘小瑚,刘时中,赖慕贤,张冠群,陈一玲 656true 曾一鸥,徐愤 655true 吴显荣,梁鸿秋 654true 徐嘉芳,孙炳荣 653true 210的抗原簇十肽的研究,探讨了小肽氨基酸序列直接测定的快原子轰击质谱法(FABMS)。从谱图中可以观察到显著的分子量信息和序列离子,并由此确定出肽的氨基酸序列。结果表明,一般C-端无碱性氨基酸时肽链比较容易形成N-端序列离子。 对掺杂有氧化态的还原型谷胱甘肽及其经巯基乙醇处理后的混合物FAB谱图的研究表明,后者具有更强的分子离子峰和更完整的序列离子,为含有胱(半胱)氨酸的肽序列分析提供了一个方法。]]> 李滨,张国赏,李世华,杨晓华,王光辉,黄婉治,孙思泉,王淳,鲁子贤 652true Gγ和 ^Aγ链比值,具有准确、快速和步骤简便等优点。将凝胶干燥后作区带的双波长扫描定量,不影响测定结果,有利于标本的长期保存和进行大量的筛选工作。]]> 刘永明,南国华,张更荣 651true 3H]-spiperone作为特异配体,与人的淋巴细胞膜上多巴胺受体进行结合反应,在淋巴细胞浓度1×10⁶个/ml,反应温度37℃,反应时间60min条件下,此结合反应具有低容量和高亲和力的特点。K_d=8.87nmol/L, B_max=181fmol/l×10⁶个淋巴细胞。用单点法分析,34例正常人特异结合平均值为139(fmol/1×10⁶LC)。此法用血量少重复性优,从而适用于临床研究。]]> 董竞武,刘春芳,全新荣,丁训诚 650true 杨建涛,王秀琴,吴旻 649true 叶正华,孙大业,郭季芳 648true E.coli tRNA^Leu简便而稳定的纯化方法。粗tRNA经过BD-Cellulose柱层析和聚丙烯酰胺凝胶电泳两个步骤即可得到亮氨酸接受能力为1400pmol/A₂₆₀单位的tRNA^Leu。]]> 黄守廷,张星岳,李冰,林胜祥 647true 陈定南,刘布鸣,樊亦军 646true Pseudomonas maltophilia)HCG受体进行重组,经电镜及结合实验证明该法是可行的,作者对pH及金属离子对重组的影响进行了初步探讨。]]> 王德恭,陈曼玲,邱明均,雷幼导,李光容,干德全,蓝天鹤 645true 张维波,刁云程 644true 3H标记物测得回收率分别为96.4％与96.5％,分离一个样品约需12—14分钟,分离了600份精浆样品,经放射免疫测定得到满意结果。]]> 杨惠钟,缪钟瑞,贺知行,姜苏,曾福祥 643true 费正,庄庆祺,梅美珍 642true 35S]dATP制备DNA探针,用于检测真核单拷贝基因并初步获得了满意结果。本文还叙述了 ³⁵S取代 ³²P中标记DNA探针和Southern吸印杂交时,适宜的反应条件,优点及其意义。]]> 陈俊杰,文一,游乐然,王若菡,张秋萍 641true 刘亚霞,陈勇,张明伟,姚志建 640true 徐端正 639true 刘训健,屠一锋,陈荣妹,王红艳,周志芹,施绍军,吴忠祥,程薇,朱琳,赵阳 638true 张明,陈慎,史美德,陆惠民,王秀春 637true 吴加金,朱伟雄,曹德贤 636true 黄文林,刘虹,孙松柏,王汉中,陈俊,吴晰莹,罗经,杨学楼 635true 魏珊,任永忠 634true 徐秀璋,张伟 633true 党进军,孙志贤,夏寿萱 632true 蓝开蔚,黄建鸣,谢之荣,邓碧芳,方允中,刘智峰 631true 杜林芳,党连凯,陈传涓 630true 彭腾,刘秉文 629true 康建,初俊杰 628true +生成的速度作为酶活力的指标,在560um波长和pH7.4,以酚红作指示剂,建立了pH-比色测定肌浆网CaATPase(Ca²⁺,Mg²⁺-ATPase)活力的分光光度法。方法简易,可观察反应进行的过程。SR CaATPase对底物ATP的K_m=97.4μmol/L;在22—42℃间求得活化能(E_Ca)=20.40千卡。用本法初步观察了汉防己甲素(简称汉甲)对酶的抑制作用。]]> 陈兰英 627true 李林,潘济文,许根俊 626true 蒋作君,沈一平 625true 周群,毛良 624true 郑榕岚,陈惠黎 623true 朱迺硕,徐秋节,顾全珍 622true 2mG为例阐述建立RIA质量控制方法和制定质量控制指标。采用自制质控血清和国产微机放免仪的数据处理程序,均能满足WHO对质控的要求。]]> 陈泮藻,李振甲 621true 60Co辐照法聚合了直径1微米、大小均匀的羟基微球。用羟基微球制备了固相二抗,并成功地应用于T₃、T₄、TSH、β₂-MG和地高辛的RIA中。观察了用固相二抗识别人辅助T淋巴细胞的效果,结果与荧光标记二抗法的结果相符。]]> 沈荣森,王仁芝,宋家云,刘桂波 620true p＜0.01)。本法为临床检验和基础研究提供了新的途径。]]> 孙雅贤,张连珊 619true 3H-NAN)的有效方法。其步骤主要采用在碱性环境中使氚水中的氚元素与游离乙酰神经氨酸(NAN)第三位碳原子上氢元素发生交换而得放射标记物。然后在CMP-NAN合成酶的作用下使其与CTP反应而得CMP-H-NAN。本法的特点是流程简便,成本低廉,CMP-NAN合成酶的提取与保存十分方便。]]> 叶建南,顾天爵 618true 3H-酪氨酸比放射性基本恒定,蛋白质合成与分解速率基本不变。测定正常大鼠比目鱼肌酪氨酸掺入,释放和净释放,结果稳定,重现性好。此外,我们还观察了介质中亮氨酸、胰岛素的影响。]]> 黄涛生,董燕麟 617true 宋小军,翁为民,袁锋,孙复川 616true 史天良,邓国仁,刘秀怀,苗晶,许毅 615true 应文斌,张振范,王庆诚 614true 3H-秋水仙碱与微管蛋白的特异性结合及DEAE纤维素对微管蛋白的离子交换作用,以测定 ³H-秋水仙碱微管蛋白复合物的含量,了解脑神经原的分化状态。此法简便、快速,稳定、经济。]]> 李兰戈,郭守祥,崔汝珍 613true 王成莲,刘莉 612true 黎健,蒋雷,王抒,李健斋 611true 4)₂SO₄和CCl₃COOH沉淀,及Cibacron blue F3G-A-SephadexG-100凝胶柱层析,经二步提纯了人血清α₁-酸性糖蛋白。PAGE鉴定,在阳极端仅显示一条蛋白带。Schiff氏试剂染色阳性,证实为糖蛋白。SDS-PAGE测得其分子量为45000。免疫电泳结果表明,纯化的α₁-酸性糖蛋白与兔抗人全血清及免抗人α₁-酸性糖蛋白均呈现单一沉淀弧。氨基酸组成测定亦与文献报告的结果基本一致。本方法简便、省时。]]> 陈志毅,薛侃,吴亦英,赵学海 610true E.coliB 同时分离和纯化四种酶的一般方法。先用硫酸链霉素沉淀把RNA连接酶,DNA连接酶与多核苷酸激酶和DNA聚合酶加以分离。然后用DEAE纤维素柱层析把DNA连接酶与RNA连接酶加以分离,用DEAE-Sephadex-A50柱层析把多核苷酸激酶与DNA聚合酶加以分离。本文着重介绍T4DNA聚合酶的分离纯化。]]> 刘佑国,宋桂云,韩子杰,刘中昌,王淑娟 609true 徐燕,谷伯起,李林,许根俊 608true 余健,黄晓春,何晓松,戴美红,朱秋林 607true 施产甫,许琳,肖祥华 606true 陈惠鹏,孙志贤,党进军,姜国芝 605true 陈泮藻,张敬礼,李振甲 604true 阎宏涛,邓延倬,曾云鹗 603true CV=2.6～6.0％,批间CV=6.9～7.9％,回收率97.7—106.1％,可测范围为1—500ng,适合测定血清及体液中微量CuZn-SOD。]]> 田亚平,沈文梅,刘智峰,陈吉中,方允中 602true 2-dhfr载体质粒SV40早期启动子下游60碱基对(bp)处重组的pSVEHβ₁质粒导入中国仓鼠卵巢细胞二氢叶酸还原酶缺陷型株,简称CHO-dhfr^-细胞。共转化后,于选择培养基中长出的265个细胞克隆中随机挑出13株细胞克隆进行表达水平检测,其中7株细胞有表达,表达阳性细胞克隆株占54％,共转化率为1.33×10^-4。]]> 于曼,王晓鸣,王嘉玺 601true 刘启光,尹长城,沈子威,赵南明,吴旻 600true 沈岩,刘毅,罗格,王申五,张平,李希儒,吴冠芸 599true 4H经硫酸铵分段盐析,DEAE-纤维素柱层析,Sephadex柱层析和HpLCmono-Q阳离子交挟柱层析,再经羟基磷灰石柱纯化,得到其纯度可达90—95％的产物。酶活性为212LTB₂nmol·mg^-1·min^-1。较纯化前活性提高350倍。SDS聚丙烯酰胺凝胶电泳显示酶的分子量为68000—70000的单体蛋白质。与以前报道人红细胞LTA₄H不同。]]> 富继义,吴大勇,李振甲,杨梅芳,刘景汉,Olof Radmark 598true sAgMcAb IgG为IgG₁亚类,不含IgM杂质;提纯的HB_sAg McAb IgM进一步确证为IgM,未检出常见的IgG杂质。]]> 罗玉芳,范春荣,黄劲松,杨力 597true 彭玉麟,史延茂 596true 张红 595true 陈玲妹,Finn Wold 594true -11mg,与放射免疫检测方法相似。]]> 金灵,苏新 593true 邱娟娟,刘瑞莲,汪卫华,范培昌 592true + RNA为模板,通过逆转录酶制备标记的第一链cDNA探针的最佳反应条件和纯化方法进行了研究,并探讨了这一方法的应用价值。本文为同步研究多种基因在细胞中的表达提供了一可行的新途径。]]> 沈珝琲,刘泽津,吴宁华 591true 张鲁榕,孔宪涛,张浩,葛依工,马健,龙振洲,马树俊,田渭涛 590true 125Ⅰ-蛋白A的效价等方面进行了讨论。]]> 卢义钦,刘俊凡 589true 徐成汤,张孔华 588true E)与α链、δ与 ^Gγ链,测定了20例正常人溶血液δ链的含量(1.12±0.44％)。并对1例HbE/β⁰-地贫家系4位成员的HbE和HbA₂含量进行了同时分别测定,其结果表明该方法稳定、可靠、易行。]]> 颜刚,朱定尔,袁恬莹 587true -1·s^-1。标准差为±0.082,其直方图为单峰形,基本呈常态分布。它的稳定性表明在疾病时对它的测定具有参考意义。分离所得粒细胞的纯度和存活率可影响其泳动率。纯度愈纯,存活率愈高泳动率值愈可靠。双层分离法所获粒细胞较纯,并同时可获纯化淋巴细胞供其它实验用。]]> 孙玲,许华林,徐迎辉 586true 罗玉芳,丁锡申 585true 3+标记技术中的pH值、螯合剂用量及反应时间等诸因素的影响,选出了最佳反应条件。]]> 陈素娟,李振甲 584true 贺永怀,陈兴,汲言山,赵薇薇,沈倍奋 583true 金仕萍,凌俊,张伟成 582true 刘训健,赵阳,朱琳,屠一锋,朱樱,虞虹 581true 125I-血凝块溶解试验表明尿激酶前体可特异地诱导血凝块溶解,对血浆纤溶系统无明显激活作用,血凝块溶解的时间曲线呈特征性“S”型。所得尿激酶前体是一种新的有别于尿激酶的纤溶酶原激活物。]]> 史伟,张彩英,黄桂秋,王振义 580true 刘昌玲,王国庆 579true 陈盛,吴海生 578true 25的反应体系中,使TdT催化εdATP加接至oligo(dA)₂₅的3′-OH末端可得聚合产物,经分离、酶解后,测定游离εdATP的荧光强度并根据εdATP的掺入量测定TdT活力。方法简便、灵敏,测定范围较宽、重现性好及无需放射性底物。适用于临床定量检测白血病患者白细胞中TdT酶活力及基因工程中TdT工具酶活力的测定。]]> 张华,林卓坤,张军 577true 5个细胞,简便、精确。保留值的变异系数小于2％。实验中发现了间歇时间现象并予解释。]]> 陈义,竺安 576true -14mol/L、1×10^-12mol/L和1×10^-9mol/L,是一种灵敏、快速的测试方法。]]> 吴自荣 575true 陶家平,陈捷光 574true Laminaria japanic)具有解壁或破壁作用的工具酶,从皱纹盘鲍(Haliotis discus hannai Ino)的消化腺提取制备了鲍鱼酶干粉。本文报道鲍鱼酶的制备及其主要性质,并与贻贝酶进行了比较。]]> 王运吉,刘金珍,孙勉英,陈俅,高绪生 573true 韩刚毅 572true 康建,初俊杰,赖舒华,常奎忠 571true 隋德新,姜涌明,赵国骏,马玉琏,施伟,姜嘉娴,严锦文 570true 马维骏,杨胜利,邹冈 569true CV为3.16％,5’-AMP在17.0—90.7pmol/10μl、cAMP在138—1104pmol/10μl浓度范围内,相关系数分别为0.9986和0.9950。用5’-AMP生成率和cAMP的转化率表达PDE活力,两者吻合。本方法能灵敏地反映茶碱对PDE的抑制作用。]]> 韩金祥,王美岭,冯进波 568true 3H]-酪氨酸分析,直接测羟基化的酪氨酸量。根据测得的“总dpm”、“酶样品dpm”和“空白dpm”计算出微量样品中酪氨酸酶的活性。另一种方法是将各个含酶样品通过SDS-PAGE分离和适当处理,放入含多巴的磷酸缓冲液中染色,待深棕色的酶带完全显现后,再经过固定等,直接将凝胶进行光密度扫描,根据各酶带吸收峰的高度即可测出酶活性的相对变化。]]> 杨昌凤 567true K_m值和V_m值等。该程序用BASIC语言编写,在IBM和APPLE-Ⅱ微机上运行通过。]]> 仲飞,邵翠红,高山林,李秀锦 566true 常碧影,阎惠文,左江湾,张明 565true 刘毅,沈岩,徐燕英,吴冠芸 564true 肖蕾,田园,吴旻 563true 杨福愉,邢菁如,陈文雯,张靖溥 562true 蔺福宝,潘华珍 561true 3McAb和2C₁₀McAb,取得了比较理想的效果。]]> 施维,彭彩霞,刘成贵 560true 金春华,祁国荣,杨义力,徐仁宝 559true 宗勤,张鸿良,奚国良,高怡生 558true 邢蕴芳,彭程航 557true 陈农安,夏志清,何东明 556true 傅培云,M. C. KING 555true 丁力,吴炳辅 554true 刘西平,袁恬莹 553true T.aestivum L.)线粒体蛋白质进行了分析。电泳结果表明:改良后的电泳系统稳定性和重复性较好,并且分辨率较高;考马斯亮蓝染色图谱中线粒体多肽呈现150—180个斑点;本文还就一些技术理论等问题进行了讨论。]]> 司智海,刘植义 552true 4)₂SO₄沉淀,二次不同pH的DEAE-Sephacel离子交换柱层析及Sephacryl S-200分子筛柱层析从人癌性腹水中分离并纯化了PⅢP,并制备了抗血清。经SDS-PAGE鉴定为均一蛋白带,分子量约为47kD。经西德药盒测定,与西德、芬兰PⅢP抑制曲线平行关系良好。氨基酸组成测定亦与文献报道基本一致。抗血清效价较高,特异性强。本研究在方法学上有一定创新,提纯方法简便易行。]]> 李新民,殷蔚荑,李忆梅,薛竹,马兰 551true 1R)的ELlSA检测法。5只大鼠肝胞液GR_1R/mg蛋白为1.0875±0.0257(扫描值)。本法特异性好,适用于没有GR纯品,而Mab数量不多条件下GR_1R的检测,其原理也适用于其他受体蛋白的测定。]]> 张斌,徐仁宝 550true 曾章新,朱忠勇,戚少然 549true 32P]-dATP 和 [γ-³²P]-ATP分别对寡聚核苷酸的3’-末端及5’-末端进行标记,研究这两种标记方法的技术途径,并结合斑点杂交,比较这两种末端标记的探针的灵敏度及特异性。结果表明:[α-³²P]-dATP虽可在寡聚核苷酸的3’-OH末端标上多个[³²P]-dAMP分子,但所得标记探针的杂交灵敏度及杂交体的稳定性均不及[γ-³²P]-ATP标记5’-末端制备的寡聚核苷酸探针。因此,当实验需要极高灵敏度的寡聚核苷酸探针时,以选择[γ-³²P]-ATP标记其5’-末端为宜。]]> 甘立霞,陈鸿书 548true K_a=4.94×10^-10mol/L。α-hANF应用氯胺-T氧化法进行 ¹²⁵I标记,再经DEAE-SephadexA25柱层析纯化,得到单碘 ¹²⁵I-α-hANF,比放射性为300μci/μg左右。最小检出量为1.8pg/管。与8种肽交叉反应为:α-rANF 98％、心房肽Ⅲ 40％,其它6种无交叉反应。样品变异系数,批内:4.4％,批间:16.3％。]]> 汪家瑞,徐宝钢,何士大,温绍君,于仲元,陈建军,王宏燕 547true 王顺友,戚少然,唐玉钗,朱忠勇 546true 1含量为44.3％,CK-MM₂为38.9％,CK-MM₃含量最低为16.7％,MM₃/MM₁比值小于1。而12例患者血中CK-MM亚型有明显变化,初步证实本法对早期诊断急性心肌梗塞(AMI)和溶栓治疗后判断是否出现再灌注有较高的临床价值。]]> 唐志毅,杨振华 545true 2O₂的方法。研究表明,PMNs为1×10⁶/ml、TPA为100—300ng/ml和测定波长为620nm是较理想的测定条件。该法简单易行、稳定、无需特殊的试剂及仪器设备,适合于一般实验室常规研究抗氧化剂、抗促癌剂的作用和作用原理。]]> 孙士勇,韩锐 544true 高又新,戴天力,杨占秋 543true 隋德新,陈天,姜涌明,史永昶 542true 梁世中,木下晋一 541true 2+含量试样中Ca²⁺浓度EPMA测定值与原子吸收光谱测定值做了比较。分别获得相关系数为0.994和0.989。这些结果说明用EPMA分析生物薄试样的结果是可以信赖的。]]> 丁浩,钟慈声,凌诒萍 540true 李希强,陈莉,宋家云 539true 王丽华,卞和如,彭程航 538true 50测定的新方法。与经典LD₅₀测定法比较,该法简易、经济、快速,结果可靠,特别适用于蓖麻毒素和凝集素这类作用慢、毒性强的毒蛋白的急性毒性试验。]]> 詹金彪,周佩珩 537true 李克 536true 王会,邓国仁 535true 左伯莉,邓延倬,曾云鹗 534true -6mol/L,而躁狂症病人的红细胞内ACh/Ch的活度值为98.3±41.4×10^-6mol/L,是正常人的4倍。本文对ACh/Ch离子选择微电极的结构和特性参数亦作了描述。]]> 余湢,曾宪英,洪文兵,奚国华,丁德云,周君富,徐嗣荪 533true 3H, ¹⁴C, ¹²⁵I及 ³⁵S其计数效率(E％)分别达34.1％,89.9％,60.3％及77.4％。液相及两种固相闪烁体间的变异系数(CV％)范围为5.1％—10.3％,同系列样品对不同厂家型号的液闪谱仪,测量效率趋一致。其测量效率、精确度、平行度等近于或优于液相测量。对数波谱分析表明无需淬灭校正并可用于双标记测量。用固相闪烁体制样不需闪烁液,故无毒、无污染、污物体积小且使用方便,克服了液体闪烁测量的不足。因此是较理想的可推广的新型样品制备与测量技术。]]> 宋兰芝,侯桂珍 532true 张迺哲,边立军,付宏杰,孙雅贤,刘志宏 531true 王春霞,卿晨,金长振 530true 50)为6.39mg。]]> 黄德如,黄东宏,郭似旋,潘克桢,黄自强,林建中 529true 杜浩,方健文 528true 荣墨克,谢风,孙荣武,吕风昌,印璞 527true 叶群瑞,陈伯权,吴美英 526true -3mol/L磷酸吡哆醛),37℃时器件性能最优,同时还考察了硅烷化及膜厚对器件性能的影响.用该传感器初步检测强化赖氨酸饮料的含量,结果与经典的茚三酮显色法基本一致.]]> 俞宝明,李幼荣,汪正孝 525true 卢春林,陆斌,韦钰 524true P＞0.05).同时还预测了49种磷脂酶A₂的等电点.这一预测结果不仅对这类酶的分离纯化有一定参考价值,也有助于了解磷脂酶A₂同功酶的性质.]]> 郝军山,冯晓勇,袁静明 523true 冯岚,马大龙,肖波,周宝宏,狄春辉,阎海,宋泉声,龙振洲 522true 吕小虎,陆明刚,李喜青 521true 何红兵,陆青,潘玉先,李留洋,黎梅兰 520true x±SD);回收率为98.4±7.4％。测定值与RIA法测定值比较,相关性良好。]]> 魏文清,王仁芝,蒋中华 519true 邓巧临,来鲁华,徐筱杰 518true 陈劲春 517true 陈书琨,沈正达,胡永浩,王蒲 516true 32P,作为探针与高梁叶绿体DNA(ctDNA)进行分子杂交。结果证明油菜4.5Sr RNA可作为公用探针,对一般植物,特别是高等植物进行分子杂交研究。杂交的结果得到两条带。]]> 周强,韩晓光,许卫东,蒋五玲,程振起,李御宇,赵微平 515true 刘立军,薛光行 514true 邰子厚,李邨,杨昌正 513true 倪红兵,金沙 512true 许凤浩,刘在贵 511true 汪俊军,庄一义,朱建民,许平 510true -4—1.0×10^-2mol/L,检出限为5.0×10^-5mol/L。并对介质条件,pH影响,选择性以及动力学响应行为进行研究,电极寿命达一个月以上。电极用于合成样品测定,效果满意。]]> 狄平平,邓家祺 509true 查锡良,任常春,陈惠黎 508true pI6.7)不同。]]> 傅红,郭佐,陈宜张 507true 梅筠,苏新,李红 506true 邰子厚,杨昌正 505true 刘江惠,左连富,郭建文 504true 汪乃兴,张晓岚 503true -8mol/L,并能对抗坏血酸和多巴胺进行分辨。实验表明,这种恒电位预处理方法简便实用,灵敏度高而稳定性好,完全适合神经递质的离体和在体分析。]]> 彭图治,吕红环,朱萍,刘国卿,曹于平 502true 戴伟文,熊建平,郝治平,夏宗芗 501true 蒋可,A.L.BURLINGAME 500true 2+存在下,活化的蛋白激酶C以ATP为磷的供体使组蛋白H1磷酸化。用Dowex-1柱层析分离反应后的ADP与ATP,再用酸性磷酸酶水解ATP的磷酸酯键,测定磷的含量,建立了蛋白激酶C活力的非同位素酶解测定法。此法可靠易行。CV=5.2％。]]> 张泽林,刘燕燕,卢波,张慧 499true 康建,董宝印,姜志明,初俊杰 498true 林启山,曾繁杰,蒋丽金 497true 325)。方法简便、快速,比用480nm的方法更为灵敏,并有良好的定量性和重复性。]]> 葛春华 496true 吴维,林波海,张幼苓,曹绍棨 495true ·的化学发光体系;用抗坏血酸-Cu²⁺-H₂O₂产生OH^·,加酵母扩增化学发光,并通过对测定条件的研究,得到测定的最佳方案。所做结果证明,其体系灵敏度高、稳定性好、特异性强、操作简便、测量快速,值得推广。]]> 陈季武,胡天喜 494true 解用虹,徐秀双,郭刚,郭善一,王维兆 493true 3H-UR, ¹⁴C-Leu, ¹²⁵I-UdR为前体,采用三标记参入方法,更严格地在同一样品中同时观察了淋巴细胞染硒前后DNA,RNA,蛋白质的合成及变化。结果表明该方法可行,且显著提高了实验效率;三种受试硒化合物在10^-8—10^-4mol/L浓度范围内对DNA,RNA,蛋白质合成均具有双相性影响,在中毒浓度时,三种硒化合物的毒性顺序为:亚硒酸钠＞硒酸钠＞硒蛋氨酸。]]> 原瑜,贾鹏翔,王德全 492true 张振瀛,李天玉,荆家海 491true 李新荣,汪洛,韩红 490true 尚世铉,单锦安,郑东东,张云,李素文 489true 温进坤 488true +和双硫腙检测。与原法比较,本法省去离心一步,但需要加入聚乙二醇(PEG)～6000作为保护剂。用本法可测定蛋白质含量低至0.2μg/ml的样品。本法操作简单、快速、经济,具有较好的可重复性。]]> 蔡辉国,马双 487true 李晓春,姚新民,陈润生 486true 金宏,高兰兴,王宗印,许志勤 485true 黄仪秀,张磊,朱圣庚 484true 洪扬,雷虹 483true 赵西林,陈雄伟,陈雅文,刘戈,孙宝勇,陈德风 482true 胡伟平,张先恩,李翔,张治平,张晓梅,张兴 481true 邹晓明,王帆,陈显川,王希成,周海梦 480true 张文武,许春玲,洪嘉玲 479true 洪瑛,刘秉文,傅明德 478true d=0.5cm),使用 N-甲基吩嗪甲基硫酸盐 (PMS) 和铁氰化钾为介体,间接地测定酶促反应中生成的还原辅酶 I(NADH).工作电位+350mV (vs.Ag/AgCl),L-苹果酸测定的线性范围为 25μmol/L—300μmol/L,响应时间小于60s,电极的使用寿命可达10d.并对电极的选择和重现性进行了讨论.]]> 纪学锋,章咏华 477true 阎有功,解兵 476true 铁锋,潘爱华,李令媛,王文清,茹炳根 475true 邱广明,孙宗华 474true 张明志,张光毅,赵升皓 473true 耿勇志,大山ハルミ,山田武 472true 125I-EGF 采用 Iodogen 方法,其标记率为50%左右, ¹²⁵I-EGF 对受体的结合率为20—30%.大鼠肝细胞膜 EGF放射受体法的灵敏度为 28pg/管,精密度为6.3%.应用此法测定了大鼠血清,颌下腺和唾液中的 EGF 的含量.]]> 贺师鹏,黄天贵,黄力新,郭淑英 471true 侯巍,杨述红,孙长青,孙荣武 470true 范慕贞,许开明,曹淑兰,吴翚 469true 3+方法,BCPDA-Eu³⁺标记物荧光光谱研究以及固相时间分辨荧光免疫分析法检测甲胎蛋白异质体(AFP-R-LCA)方法的建立.结果表明 BCPDA 能在温合条件下与蛋白质氨基结合并与 Eu³⁺螯合,BCPDA-Eu³⁺蛋白质标记物荧光特性、标记比度、生物结合活性与国外同类产品一致,所建立的检测 AFP-R-LCA 免疫分析法最小检测值0.6ng/ml,为提高我国非放射性同位素标记技术水平奠定了基础.]]> 韩玲,陈杞 468true 王升启,马立人 467true 郭佐,陈宜张,郑尊 466true 125I发生反应的酪氨酸或组氨酸残基,我们用3-(4-羟苯基)丙酸-N 琥珀酰胺酯做连接剂,通过酰氨键将酯连在 AAP 肽的末端氨基上,再将 ¹²⁵I 标记在酯的羟苯基的2,5位置上,成功地建立了 AAP 放射免疫分析法.]]> 孙雅贤,杨鸣岗,孙阿成,王赋敏,周峥 465true r=0.9989),线性范围(10—3000ng),平均回收率(97.33%)及平均变异系数(5.5%)均属优良.]]> 王升启,马立人,张京生,石成华 464true 张迺哲,赵会军,付宏杰,宋玉忱 463true 孟安明,齐顺章,宫桂芬 462true 田小利,徐堤,陈兰英 461true 王俊茹,邓国仁,刘为纹,吕有勇,李文梅 460true 125I 标记同一抗体的放免法同属 pg 水平.加入保护剂低温保存,使标记物的使用期由原来的1个月延长到6个月.]]> 刘农乐,蒋滋慧,赵明,王会信,赵强,周廷冲 459true 2 和 (γ-³²P)ATP 条件下,仍然保留胞内所具有的对 EGF 敏感的使受体自身磷酸化的蛋白激酶活性.]]> 刘以民,陆士新 458true 李银妹,高成岳,姚焜,郭光灿 457true -9mol/L 亚硒酸钠(S)及1mg/ml 牛血清白蛋白(BSA)等诸种添加剂成分而构成了本试验的无血清培养基,定名为 LDSF.试验表明,LDSF 可取代常规培养基 DMEM(含10—15%胎牛血清),用于骨髓瘤、杂交瘤细胞的长期传代培养,支持杂交瘤细胞稳定、持续地分泌特异单克隆抗体(McAb),并可用于细胞融合、冻存和复苏.]]> 邓辉南,刘秀梵 456true f_s 和机械阻尼电阻 R_q.随干燥固化进行,f_s 开始降低经极小值后突增转慢变化;R_q 则很快增加达极值后迅降而趋稳定.f_s,R_q 开始突变的时间、峰值大小均随 Hct 增而降.初步探讨了压电响应与血液粘弹性及血块力学性能之间的关系和这种技术的应用潜力.]]> 周铁安,聂利华,姚守拙 455true 李伍举,吴加金 454true Zhang Jun and Lin Zhoukun 453true in vivo neutron activation analysis(IVNAA)was carried out,and the average value of the phosphorus percentage content which were measured for ten rabbits was (1.26±0.01)%.]]> Luo Xianqing,Wu Jingping,Wang Haiying,Huang Hanqiao,Liu Xiaohua,Lu Xihai,Yu Aiping and Luo Qiandi 452true Chen Jun,Wnag Huimin,Li Manzhi and Wu Yintang 451true M.arginini,M.orale,M. hominis ,M .hyorhinis,M fementans and A.laidlawii). When the DNA of 6 species was used as the template, primers F1 and R1 produced fragments of 340 to 468 bp,and primers F2 and R1 produced fragments of 145 to 211 bp. No discrete band was observed in electrophoretic gels when Hela cell or E.coli DNA was served as the template with the use of primers F1 and R1. As little as 8.5fg DNA of M.arginini，approximately 1 3 organisms could be detected. This suggests that mycoplasma contamination to cell cultures can be detected by PCR.]]> Wang Zhengsen,Wu Jianxin,Zhao Xiaoyuan,Sun Baoling,Guo Zhanggai and Li Min 450true Huang Rubin,Pan Ying,Wang Zhesheng,Tong Dashan and Shi Xiaoling 449true Tie Feng,Ru Gang,Li Lingyuan,Liu Defu and Ru Binggen 448true Luo Ying,Sun Zhixian,Yang Ruibiao and Zhang Zhensheng 447true s (stimulatory GTP-binding protein) and adenylate cyclase (AC) from cell membranes of bovine brain cortex were extracted with 1% sodium cholate and 15% saturated ammonium sulfate. Separation of G_s and AC was carried out by Sepharose 6B gel filtration. Purifiled G_s can be obtained by passing the fractions containing G_s from Sepharose 6B column through a heptylaminc Sepharose 4B hydrophobic column. The purity of G_s was identified by its highly stimulated activity to AC and SDS PAGE which showed two bands of 45kD and 36kD. The procedure described above is characterized by simplicity, rapidity, repeatability and high yield.At the same time,AC,a by-product which was not contaminated by G_s, can be used for assay of G_s, activity after reconstituting it into asolectin vesicls. This method of assaying Gs activity has been proved to be simple, reliable and sensitive.]]> Fan Gaofeng and Huang Youguo 446true Pan Ying,Huang Rubin,Wang Zesheng,Tong Dashan and Shi Xiaoling 445true 1F is 0.3698,Gc^1S, 0.2812, Gc², 0.3490. There was good agreement between the observed and the expectated value. (Σx²=1.057, P＞0.70).]]> Guo Yaojun,Guo Qiang,Huang Lili and Yu Zhongyi 444true Liu Qinghui,Liu Depei and Liang Zhiquan 443true Rong Zhengxing,Liu Huizhong,Bao Jingqi,Chen Hongzhuan,Sun Yuyan and Sun Chen 442true 4 to 205×10⁴ and no cross-reaction occured between TSH antisera and human LH, FSH, HCG and all antisera have the avidity more than 10¹⁰L/mol.]]> Zhou Ling 441true Zhao Qiren,Zhang Fuhua,Lu Jie and Lin Han 440true 2+ chelate affinity chromatography.It was shown in three experiments that the special chromatography held a number of important advantages for protein purification,such as a high rate of repeating performance and a large protein capacity. The purified enzyme,with a specific activity of 3073 U/mg protein, was tested for homogeneity by activity-stained and SDS gel electrophoresis.Accompanied by the study,a simple and efficient method was worked out for assessing the homogeneity of CuZn-SOD using its ratio of the absorbence at 260nm to that at 280nm.]]> Lu Xing,Chen Jizhong,Li Peifeng,Yang Suhong and Fang Yunzhong 439true CVs) of two samples were 3.8% and 4.7%.Day-to-day coefficient of variation (CVs) was 7.0%.The correlation of immunoprecipitation method and electrophoretic procedure were cinsistent (n=22, r=0.976).Reference values for total LD and LD1 were 102.3±16.4U/L and 23 .7±4.4U/L respectively. The ratio of LD1 to total LD was 23.1±3.9%.The advantages of immunoprecipitation method were:high specificity. good precision and linearity. easy operation. Immunoprecipitation method was very suitable for measuring LD1 and could adaptable to the automatic analyzer.]]> Wu Xiyun,Yue Xiuling,Chen Yan,Si Xuezhong and Wang Zhongquan 438true Guo Yaojun and Wen Tao 437true Du Hao,Fang Jianwen and Zheng Jinju 436true Zhu Shudong,Zhao Huiren and Zhao Shenghao 435true Zhang Hongquan,Wang Huixin,Zhou Tingchong and Wang Yunling 434true 35 S dATP and Taq DNA polymerase. The experiment showed that it is simple, rapid and stable. This method was used to analvze the tumor suppressor gene p53 mutation in human esophageal eancer. It was found that there were point mutation,insertion and deletion frameshift mutation of p53 gene in human esophageal cancer. Intron 5 and 8 sequences of p53 gene in human and Rhesus monkey were sequenced and in monkey they are 81 and 92 nucleotides respectively.]]> Li Huachuan and Lu Shixin 433true Lin Bo-hai 432true E.coli were dissociated successfully by high intensity ultrasound in a suspension of 4mol/L urea instead of using 8 mol/L urea as solvent.The SDS-PAGE of suspension samples processed by ultrasound shows the same band at 17 000 as that solubilized by 8 mol/L urea.The results show the possibility of developing a new ultrasonic technique for the dissociation of inclusion bodies.]]> Wang Jin,Hua Zichun,Fang Yong,Tang Weidong,Zhu Dexu,Feng Ruo,Zhu Changping,Huang Jinlan and Chen Zhaohua 431true Wang Shengqi and Zhu Baozhen 430true 2.The synthesis was carried out with SPPS and Boc strategy.The amino acid composition was found in agreement with its caculated values. The purity was 97.7%.The bioassays showed that it enhanced the growth of young mice significantly and this effect depends on the dosage of injection. GHRP is more sensitive to the younger mice.]]> Hu Xiaoyu,Wang Qin,Wang Rui,Gao Liwei,Shen Jianmin and Wang Yongqian 429true I is 4.7.Amino acid composition analysis showed that NSE is an acidic protein.]]> Guo Jian,Zhang Shiming,Zhou Runqi,Chen Shigen and Han Yipin 428true Corynebacterium glutamicum 629,coupling with potentiometric amrnonia gassensing electrode, was designed and constructed.The calibration plot of mV measurement vs. logarithmic urea concentration was linear in the range 1.1×10^-4～1.4 ×10^-2mol/L,with slope 51.2 mV/decade in pH 8.0,0.1 mol/L phosphate buffer at 30℃.The relationship between the initial response velocity and the substrate concentration was also discussed.The results indicate that the kinetic response process of the reaction catalyzed by bacterium is similar to one by isolated enzyme. By using Eadie-Hofstee plot,the apparent Michaelis-constant (K_m) and the maxium initial response velocity v_m for urease in the immobilized bacteria membrane were determined. The biosensor was relatively stable for 45 days.]]> Lei Chenghong,Bao Yafang and Deng Jiaqi 427true 1F is 0.4891,Gc^1S is 0.2432 ,Gc² is 0.2678. There is good agreement between the observed and the expected value (∑X²=1.404,0.7<P<0.8). Pi^M₁ is 0.7542, Pi^M₂ is 0.1808, Pi^M₃ is 0.0650. The agreement is good as well (∑X²=1.1233,0.7<P<0.8).]]> Guo Yaojun,Li Xinhui,Huang Lili and Yu Zhongyi 426true Shi Yu,Shi Lingyun,Liang Keshan and Zhang Zhiwen 425true s=0.0065 and v=1.26%.This method can be used in the analysis of the activity of Na⁺,K⁺-ATPase etc.]]> Wu Qizhuan,Wang Yanhua,Bao Heqiu and Wang Runying 424true Wang Lie,Yang Mingxue and Xie Guangyun 423true Luffa cylindrica by using an improved procedure that involved ammonium suifate preciptation, ion exchange chromatography on S Sepharose Fast Flow and gel filtration on Sephadex G-75.α-and β-luffins were basic proteins with isoelectric points of about 10, with molecular weight of 28 000 and 29 000, respectively, as judged by SDS-PAGE. Inhibitory activities of α-luffin and β-luffin on cell-free protein synthesis were stronger than that of any known type-1 RIPs，with ID₅₀ 10μg/L and 50μg/L, respectively.]]> Wu Shen,Zhu Yuerong,Guo Feng and Liu Duohua 422true Wang Hong,Wang Jinjuan,Li Yan,Liu Jie and Chen Weifeng 421true E.coli DH5α-pBV220/IFN-γ as probes,The result showed a great disparity between two DNA standards in colour;thus indicating that high protein amount interfere seriously in the detection of trace RC DNA and that the DNA standard supplied with IFN-γ is more reasonable than the homogeneous one.The sensitivity of the method is 4 pg and RC DNA amount existed in each dose of all samples is less than 100 pg，which satisfied WHO requirements.]]> Chen Yuguang 420true Wang Chunxin,Xie Yiwu and Liu Liangshi 419true Fang Huisheng,Xiang Bingren and An Dengkui 418true 2 extraction(SFE-CO₂)technique. The phosphorus,nitrogen and PL contents,the N/P molar ratio,the triglyceride and cholesterol of the extraction were measured by means of biochemical method,thin layer chromatography,and spectral analysis. The results showed that extracted yolk PL is 95%in purity and its N/P molar ratio is 1.003. So the SFE-CO₂ technique can be used to obtain yolk PL with higher purity quality.]]> Lai Bingsen,Mao Zhongxing,Shen Xiaojing and Sun Shuqin 417true 74A₁₀ and T₇₁B₁₁ were 1:50 000～1:150 000 and affinity constants were 7. 15 ×10⁹L/mol and 8.75 ×10⁹L/mol respectively. The cross reactivity with HCG,FSH and LH were less than 1.1×10^-6%,0.01% and 0.016% respectively. TSH IRMA was established using T₇₁B₁₁ and T₇₄A₁₀ as tracers or solid phases.]]> Liu Yibing,Zhuo Jin,Zhang Jie,Wang Yanzhen and He Youfeng 416true E. coli. By McAb affinity chromatography which prepared by combining an anti-SCF McAb with NCR-Sepharose 4B was performed. At optimum conditions,the purity of rhSCF obtained was higher than 95%.The biological activity also increased apparently.]]> Lai Chunning,Zhu Yuanxiao,Xue Sheng and Shen Beifen 415true 9. ¹²⁵I-hMSE as the tracer is prepared using improved BHR method and its binding rate with antiserum(1∶1000) is up to 50.16%. The variable coefficients of intra and inter-assay are 8.6% and 13%, respectively. The recovery rate is 95%-105%. The standards range from 5 to 320μg/L and the minimum detectable value is 5μg/L. In the assay there is an optimal reaction condition: 0.1mol/L pH7.4 PBS(5mmol/L MgSO₄，0.1% BSA， 0.1% Toween-20, 0.1% NaN₃，0.5% NaCl);and incabation temperature and times: 37℃，0.5h and 4℃，0.5h (as rapid measurement) or 4℃ 24h. On the basis of 65 healthy control，the hMSE levels are 23.9±10.9μg/L (x±s).A positive value is higher than 57μg/L. The hMSE levels are signifcantly increased in the patients with both acute myocardial infarction and muscular diseases.]]> Chen Panzao,Jin Daoshan,Wang Luhuan,Wang Shiwen,Hao Xiuhua,Gao Yuhong,Li Zhenjia and Han Zhitao 414true Du Linfang,Lin Honghui,Pan Yonghua and Liang Houguo 413true Yang Boyu,Zhu Damo and Zhang Yukui 412true n) were gained and the math relation between the minimum(R_n)of the non-base-mismatch copy proportion of PCR products and the efficiency cycle numbers (N),the copy chain length(H)catalyzed by Taq polymerase and the mismatch frequency(f)was concluded by way of substituting step by step:R_n=(1-Hf/2)^N-1(1-Hf) .The formula has a guidance sense for preparing the gene segments used for the gene expression by PCR technique.]]> Fang Yuequn and Wang Bingrui 411true Wen Houjin and Tao Jiaping 410true Bombyx mori cocoons was obtained by treatment of the neutral salt (CaCl₂). Peroxidase(POD)was immobilized in the silk fibroin membrane. Activity and characteristics of the POD-immobilized fibroin membrane were analysed.The results show that the activity of the POD-immobilized membrane is high;Optimum pH range for the enzyme membrane,being at pH5.0-7.0,was widened in comparison with the free enzyme;and its thermal stability was good.]]> Zhang Yuqing and Zhou Yuzhen 409true 2+/cysteine and the principle of TBA reaction,a simple one-step microassay for the studying and screening of antioxidants in 96-wells plate was established. The comparative studies between the procedures in 96-wells plate and in test tube were also conducted.This microassay requires only small volume of diluted microsome and tested compounds,having the advantages of reliability,rapidness,simplicity and convenience. It is especially suitable for the pilot screening of antioxidants as well as the simultaneous study for many samples. This method can also be used to measure the lipid peroxidation induced by other systems.]]> Sun Shiyong,Xu Bo,Li Qiuju and Li Runzhao 408true D-glucosaminidase,NAG)determination were applied in the patients with diabetes mellitus and with hypertension for detecting the incipient nephrological changes. The results showed that this index was sensitive to detect the early elevation of albumine excretion in urine and has been proven to be a more valuable diagnostic tool in the early diagnosis of renal damage than the tradtional urine protein test. As the urinary lysosome enzyme (e.g.NAG) is more specific and sensitive marker of renal tubular injury. it is suggested to combine the microalbumin and the enzyme assays to yield more valuable informations. The serum type Ⅳ collagen determination with the enzyme immunoassay was performed simultaneously in the same group of patients with diabetes mellitus. It was found that the mean value of serum type Ⅳ collagen was higher than that of the control group. This index indicated the dynamic process of collagen peptide synthesis occurred in the basement membrane.]]> Wei Youren,Hou Linpu,Wang Mei,Zhan Yuliang and Zhu Lihua 407true 1%,CK-MB₂%,CK-MM₁%,CK-MM₂%,CK-MM₃% can be completed within one hour. The method is sufficinently sensitive to detect the CK-MB isoenzyme and CK-MM isoforms at the concentration of lowest detection limit 2.2U/L and 32U/L respectively. Thus, this system can be used to rapidly, sensitively and precisely quautify the isoenzymes and isoforms of CK.]]> Wang Bo and Yang Zhenhua 406true CV)was 1.8%.The bienzyme electrode was used semi-continuously for 10 days，at the end of which period its respones to maltoseremained 60% of its initial value. Methods to extend the life time of the bienzyme electrode and to eliminate the interference of coexisting glucose are discussed.]]> Qu Hongbo and Zhang Xianen 405true Li Kun,Fu Jiayu,Xue Wentao and Chen Shanshan 404true Ren Xuezhen and J.N.MILLER 403true Jing Tianyu and Zhao Xiaoyu 402true 4、Ca²⁺ etc,has been studied to determine the activity of nitric oxide synthase (NOS) in rats'brain. Alter being incubated at 37℃ for 80 min in dark with samples,the sulfanilic acid and N-(1-naphthyl)-ethylenediammonium was added to the reaction system to measure the concentration of produced nitrite in system.It was found that the optimum pH for the enzyme reaction was 7.4,Km was 0.1 mmol/L.There was a relationship between the amounts of sample and nitrite concentration in the system. This method is simple and convenient. Intra-assay CV value is 3.69% and inter-assay CV value is 5.16%. The specific activity of nitric oxide synthase in ten rats' brains is (39.61±7.64)nmol/(min·g).]]> Wang Chengbin,Tian Yaping,Shen Wenmei,Wang Deqing and Jiang Cien 401true α-p-tosyl-L-arginine methyl ester) is a specific substrate of trypsin. N_α-p-tosyl-L-arginine is released from TAME after tryptic hydrolysis,which reacts with NaOH in the assay mixture and causes the decrease of pH.Using phenol red as the indicator, the PH change of the solution can be monitored by the decrease of the absorbance at 555 nm. The decrease of A₅₅₅ is directly proportional to the amount of trypsin with a linear range of 0.001～0.3 mg.The method is very convenient to use, highly sensitive and specific.]]> Zhang Dongyi,Tang Jianguo and Zhang Longxiang 400true 2O₂/Fe^2＋ was assayed by the new method.After oxidized by hydroxyl radical the A₅₃₆ of 1, 10-phenanthroline-Fe^2＋ decreased apparently.The △A₅₃₆ was dependent upon the dosage of 1, 10-phenanthroline, FeSO₄ or H₂O₂ individually. The △A₅₃₆ increased as the reaction lasted. It was demonstrated that the hydroxyl radical scanvenge effect of mannitol, ascorbic acid and thiourea was dosedependent by the new method.]]> Jin Ming,Cai Yaxin,Li Jinrong and Zhao Hui 399true + vector DNA. The positive recombinant colonies were identified by the PCR and the restriction endonuclease digesting method. Then nucleotide sequence analysis of the inserted E gene fragment was conducted directly by using the common M₁₃ primer. The result of the restriction endonuclease and sequence analysis confirmed that the 120 by of 5’-teminal nucleotides sequence of the amplified E gene fragment was the same sequence as reported.]]> Yu Man,Qin Ede,Yang Peiying,Sun Lei,Xu Pinfang,Si Bingyin and Yan Guozhen 398true 3, G₈, G₁₀, A₅, A₇), which secreted stably monoclonal antibody against human cTnT, were obtained by cell fusion, identification, cloning, four lines were IgM, one line IgG by immunological analysis. The number of hybridomas chromosomes were 92～110, the McAb titers from ascitic fluid were about 3.2×10^-6～1. 6×10^-7.]]> Li Zhiliang,Fu Chaoping,Lu Qing,Li Meilan,Qian Xuexian and Wang Suhua 397true Fan Yingxin,Wu Jiawei and Zhou Junmei 396true 2O₂ or CN^-, MnSOD disappeared in the presence of CHCl₃CH₃CH₂OH, and Fe-SOD lost in the presence of H₂O₂ or CHCl₃-CH₃CH₂OH on the electrophoresis gels, the gels after electrophoresis were treated with the different inhibitors and then stained. According to the loss or presence of these bands, different SOD types can be identified.]]> Luo Guanghua,Wang Aiguo and Fu Aigen 395true Guo Yaojun and Yu Tian 394true trans retinoic acid(RA) was established. Three cDNAs response to RA treatment were obtained by screening of the subtracted cDNA library. The results of sequencing and function analysis show that three cDNAs are novel cDNAs of differentiation associated genes in human lung adenocarcinoma cell line. This system is also suitable for isolating cDNAs representing deleted or overexpressed gene in human cells.]]> Li Baiquan and Wu Min 393true Mucor miehei catalysed esterification of organsilicon alcohol in organic solvent was explosed and the effect of various factors on the reaction was studied. The different organsilicon alcohol substrates and fatty acid substrates, organic solvent polarity and water contents etc. were studied.]]> Qiu Shuyi,Yao Ruhua,Zong Minhua and Wu Hong 392true Li Chengzhang and Fan Mingwen 391true Chen Panzao,Li Zhenjia,Jin Linpei and Guo Jianquan 390true Brachybacterium were carried out by the method in which DNA labeled with nonradioactive photobiotin was binded to heat denatured single-stranded DNA in microdilution plates. Homology values among bacteria were obtained by measuring fluorescence intensity in the microdilution wells.The strains which is difficult to further classify at the species level with morphological, physiological and biochemical characteristics were determined their appropriate taxonomic positions on the basis of the genetic relatedness among microorganisms. This method is a rapid and accurate hybridization technique and plays diagnostic role on the taxonomic study of Brachybacterium.]]> Fang Chengxiang,Akira Yokota and Mariko Takeuchi 389true Li Weiguo,Luan Xudong,Huang Tao,Zhu Ningning,Qin Xuebin,Huang Shangzhi,Long Guifang,Shen Yan and Wu Guanyun 388true +-RNA was extracted from Wistar rat brain. The first strand of cDNA was synthesized by SuperScript RNase H^- reverse transcriptase with the oligo (dT)₁₅ primer which contains Not I site. After the poly (A)⁺ -RNA was removed with E. coli RNase H, the second strand was synthesized by means of E. coli DNA polymerase I, E. coli DNA ligase and T4 DNA polymerase.Then Sal I adapter was added and the cDNA digested with Not I .Half of the cDNA was inserted into plasmid pSPORT I and transformed E .coli DH 5a. The other half was stored at -20℃. It was shown that the cDNA length ranged from 100 to 10 000 bp. Using this cDNA library as a template, four genes have been amplified successfully. They are glutamic acid decarboxylase (GAD, 1800 bp)，neuron-specific enolase (NSE, 1340 bp)，T3 receptor(1230 bp) and cholecystokinin(CCK, 345 bp).The method for storage of the cDNA library which can be kept for a longer period was also developed.]]> Song Xuewen,Zhao Chong,Zhou Ren,Guo Shanyi and Zhang Jingyu 387true Zhou Junxian,Wang Xicheng,Zhao Yauling and Zhou Junmei 386true CV) is 4.23%.]]> Zhang Xiuming,Yan Lijuan,Chai Jiankai,Zhou Weiqiang and Wang Lixia 385true r＞0.9990) over a concentration range of 0.312～10.000 mg/L. The intra-and inter-assay co-efficients of variation was 2.15%～5.40% and 1.23%～3 .70%, respectively. This method was successfully applied to the determination of COPs in cholesterol standard reference material and in human serum.]]> Dong Jun,Chen Wenxiang and Li Jianzhai 384true 0 phase cells do not produce ds-DNA cross-link.]]> Huang Jianming,Dong Yuning,Xu Feng,Wen Hao,Wang Jin and Lang Jinyi 383true Qian Jianghong,Liu Haiying and Deng Jiaqi 382true Xu Huaiqing and Chen Chuchu 381true 4OH(40:48:10:5) for polyphospho-inositides. The method can be used for comparative analysis of phosphoinositides in small samples，and also for the extraction，separation and quantitation of polyphospho- inositides. separation and quantitation of polyphosphoinositides in samples which are not labelled with isotope.]]> Ma Keli,Liu Yan and Cui Zhaochun 380true 2-chymase fusion gene transgenic mice was carried out by means of polymerase chain reaction(PCR) with two specific primers, which span across MLC2 promoter region and chymase structure gene region. The DNA electrophoretic bands of PCR products were recovered and purified, then sequenced by PCR sequencing method with one of the two primers. Final determination of the transgenic mice was conducted through comparing the sequencing results with sequences of transfered gene. This method is convenient, effective and specific.]]> HE Quan,LI Peng,JIANG Liqun and CHEN Lanying 379true WANG Yanrong,QIAN Rongli,HE Shipeng and HUANG Tiangui 378true E.coli alkaline phosphatase gene to the C-terminal of the anti-HBsAg Fd fragment gene. E.coli XL1-Blue was transformed with pHBFAP, and induced with IPTG. The HBsAg banding ability and the alkaline phosphatase catalytic activity were detected by using ELISA in the induced bacterial supernatant thus indicating that the anti-HBsAg-alkaline phosphatase bifunctional antibody was expressed successfully in E.coli.]]> GAO Rongkai,WANG Yan,LIU Qunying,HUA Bing,ZHU Yingchun and CHEN Yuping 377true in vitro immunization and RT-PCR was established. Colorectal carcinoma-associated antigen CA-Hb3 were purified through a monoclonal antibody Hb3-Sepharose 4B affinity column and analyzed by SDS-PAGE and Western blot. Peripheral blood lymphocytes (PBL) from 10 ml blood of a patient with colorectal carcinoma were immunized with CA-Hb3, rhIL-2 and pokeweed mitogen. The lymphoblast-like cells and colonies could been seen after immunization. The amounts of total RNA from the immunized PBL are 2.5 times more than that from the non-immunized. Human immunoglobulin, VH-CH1 (IgG) and VL-CL (κ), genes were amplified with RT-PCR with the above total RNA or mRNA as templates. The products of human immunoglobulin genes from the immunized PBL are 1.3 times more than that from the non-immunized. This strategy would be used for humanizing mouse-original monoclonal antibodies.]]> HU Zhiwei,LI Xiaoling,CAI Xiaohong,ZHU Jiangao,ZHOU Guohua and SUN Qubing 376true -8～10^-6 mol/L with 5 μl sample. The change of free amino acids was monitored in vivo in the hippocampus of freely moving rats before and after operational learning. These experiments suggest that the sampling and determination system can be used for analysis of amino acids in brain microdialysates.]]> HAN Huiwan,MA Mingsheng,XIONG Shaoxiang and LIU Guoquan 375true e″) against the concentration of MDA was given from 1.0×10^-6 to 1.0×10^-3 mol/L in the condition of a base solution of 0.1 mol/L NH₄Cl at scanning rate of 80 mV/s. The detection limit was 1.0×10^-7 mol/L. The method provids succesfully a rapid and simple way to determine the concentration of MDA in the sample of cardiac myocytes.]]> LI Dongfang,CHEN Xiaole and WANG Naixing 374true －₂ is able to enhance the fluorescence intensity of 4-hydroxycoumarin, a spectrofluorometric method for determination of nitric oxide in biological sample was developed. The nitrite concentration in the range of 2×10^-5 mol/L to 2×10^-8 mol/L in the sample can be measured. The method has been applied to determine the level of NO in cortex and hippcampus, cultural supernatant of macrophage actived by LPS and serum in rat.]]> WANG Jinghua,YANG Shijie and YANG Guizhen 373true 2, 1D₂ and 4B₄ were well characterized. Their Ig class and subclass were determined as IgG1 and IgG2a respectively. These McAbs reacted with a high degree of specificity to rhIL-6 and did not have cross-reactivity with many other cytokines and irrelevant proteins. Immunoblotting results showed that these McAb only recognized a single band of rhIL-6 with molecular mass of 21 ku. These McAb reacted strongly with IL-6 molecules with an affinity constant (K_aff) 1.62×10⁹ (mol/L)^-1.]]> JINAG Panhong,MO Wei,DOU Liangjun,ZHAO Xiaomeng,YUAN Tingjun and SONG Jinhua 372true -3 (mol/L)^-1·cm^-1. The dissociation constant is 1.8 μmol/L, and 0.5 mol/L NaCl could dissociate the complex. Based on these results, TCS is purified from the root tuber of Trichosanthes Kirilowii by Blue Sepharose CL-6B. This method is rapid, simple, efficient and could be applied in mass preparation of TCS.]]> YUAN Huidong,XIA Qichang and ZHANG Zuchuan 371true XU Bing,ZHU Zhongyong,TANG Yuchai and LAN Xiaopeng 370true XIAO Shangxi,WU Lin,WANG Daobin,HU Jiegui,LIU Huaping,ZHENG Bing and ZHANG Jun 369true －7～2×10^－4 mol/L. Response time was less than 30 s.]]> YING Tailin,WANG Zhaojin,LIU Haiying,SUN Kang and DENG Jiaqi 368true SHENG Wenjun,YANG Henglin,ZHANG Zhijie and DONG Baozhong 367true XIE Yonghong and GUO Gang 366true TANG Hongwu,CHEN Guanquan,MEI Erwen and ZENG Yun'e 365true GUO Yaojun,LI Xinhui and FANG Yong 364true 1H-¹⁵N HSQC, HSQC-NOESY, HSQC-TOCSY spectra of the ¹⁵N-labeled protein GAL4(62) were abtained, while solvent suppression was achieved by presaturation during the relaxation delay and by the use of spin-lock purge pulses. The important role of those 2D experiments in ¹H assignments of ¹⁵N-labeled proteins was discussed.]]> TU Guangzhong,ZHANG Riqing and ZHAO Nanming 363true LIU Yu,LI Weidao,LIN Ding,LIU Xingming and LU Ping 362true ZHANG Jingzhi,JIN Guichang and ZHOU Guirong 361true WANG Shengqi,MA Liren,YANG Peiying and ZHU Baozhen 360true 2-anticoagulation plasma and 1 000 μl PBS-substrate-solution containing 1.9 kU/L LDH (pH 8.0), then add 40 μl GLDH (≥12×10⁴ U/L) to start the reaction. Incubation periods were shortened to 5 min. The limited detection for ammonia in plasma is 4 μmol/L, and this method is linear from 6 to 200 μmol/L. The method is accurate and reliable. The analytical recovery is from 90% to 105%. The within-run CV% was≤5%. The routine condition variance of the method ranged from 5% to 10%. It was found that 1.9 kU/L LDH was sufficient to eliminate the decreace of NADH by endogenouse pyruvate and LDH in plasma. The normal fasting ammonia in plasma is 10～70 μmol/L.]]> XU Guobin,ZHU Lihua,HONG Jianmei and XIA Tiean 359true 5 U/mg protein. Reserch showed that the molecular weight was about 35～40 ku and the pI was about 3.75～4.15.The product possessed the antigenity of native HuEPO. The peptide electrophoresis result was in accord with theory deducation. 15 amino acid sequence of rHuEPO N terminal was as the same as native HuEPO. All these results described above revealed that the final product were high purity rHuEPO and the purification procedure was rapid and efficient, which can be used to produce clinic rHuEPO in large scale.]]> LI Lin,DENG Jixian,LU Jianshen and ZHOU Jiang 358true WANG Shengqi,MA Liren,YANG Peiying and ZHU Baozhen 357true WANG Tai,Hiroshi Kadokura,Koji Yoda and Makari Yamasaki 356true WU Benchuan,CHEN Zhaolie,LIU Hong and YE Jianxin 355true in vitro.]]> WANG Jiangyan,ZHANG Weining,WANG Renjie,XU Yuru and WANG Mengyin 354true Ile gene has been synthesized before. Now the synthetic tRNA^Ile gene was transcripted in vitro with T7 RNA polymerase and the optimum reaction condition was investigated.]]> ZHANG Lu,ZHONG Xionglin,PENG Zhaohui and XU Qian 353true SUN Lijun,XU Huaiqing and CHEN Chuchu 352true S/N=2) was 3.1 nmol/L. The linearity was observed from 10 to 1 000 nmol/L, and the coefficient of determination was 0.9992. The average recovery was 97.1%.]]> SHEN Zuo-Jun,WANG Zhi-Guo,LI Xiao-Peng,HU Cui-Hua and YANG Shu-De 351true GUO Da-Wei,LANG Hai-Li,XU Xiao-Li,J.C.J. EIKENBOOM and R.M. BERTINA 350true E.Coli, was found to accumulate in cytoplasmicinclusion bodies.After washing, the inclusion bodies were dissolved in 8 mol/L urea. Under the denatured states, the recombinant human IFN-γ from Chinese Han nationality was purified by size-exclusion chromatography and ion-exchange chromatography.The final yielded product was of high purity(96.87%) and exhibited the mass of molecule 17.32 ku analyzed by mass spectrometry.The renatured IFN-γ, which was refolded by diluting, had specific antiviral activity of 5.5×10⁵ U/mg. The sequence of 16 amino acid residues from NH₂-terminus of the protein was determined and was found to agree with that of hIFN-γ reported by Gray. The composition of amino acids of the protein was analyzed. The result had good agreement with that deduced from cDNA of IFN-γ from Chinese Han nationality.]]> WANG Qing-Ming,BI Jian-Jin,FAN Guo-Cai,CHEN Hui-Peng,JIANG Zhong-Hua,WEI Han-Dong and HE Fu-Chu 349true r=0.9686). the serum reference level by testing 60 cases health is 160 μg/L. It was found that the CLEIA is a sensitive, acurate, stable and specific method，it may be a qualified candidate for serum type Ⅳ collagen detemination of non-radioactive method.]]> WANG Tian-Cheng,YAO Min-Jie,LIU Xiang-Yi and KOU Li-Jun 348true TM series, was generated as first step, restriction mapping of each subclone was analyzed and then, digested the whole length phage DNA and analyzed the restriction site combined with the mapping of subclones. An accurate restriction mapping of a large insert of a phage clone, which contain mouse coagulation factor IX gene, was generated successfully with this strategy.]]> DAI Xu-ming,XUE Hong,YANG Hua,HU Yi-ping and FU Ji-liang 347true BIAN Xin,YANG Xiao-yi and HUANG You-guo 346true YU Lai-ning,FANG Yao-lin,YAO Yan-hong and XU Ying-fang 345true LI Tong-zhu 344true CAI Wen-sheng,SHAO Xue-guang,PAN Zhong-xiao and ZHANG Mao-Sen 343true BEI Ling,HU Tian-hui and SHEN Xun 342true QI Feng-ying,DUAN Hui-jun,LIU Qing-yin,ZUO Lian-fu,LIU Jiang-hui and GUO Jian-wen 341true KONG Jian,ZHU Ning-ning,YIN Bin,SHEN Yan and WU Guan-yun 340true ZHAO Da-zhong,CHEN Min,CHONG Kang and TAN Ke-hui 339true LU Yi-fan,TIAN Chai and DENG Ji-xian 338true In vitro DNA replication system derived from eukaryotes is capable of replicating exogenous plasmid DNA containing SV40 origin of replication efficiently and accurately. Such an in vitro DNA replication system has been established. In the presence of exogenous SV40 large T antigen, shuttle-vector plasmid pZ189 could replicate efficiently in monkey kidney vero cytoplasmic extracts, which provided all the other necessary proteins for DNA replication. This in vitro DNA replication system provides a useful measure for studying the composition and function of eukaryotic DNA replication system.]]> FENG Zhao-hui,YU Ying-nian, and CHEN Xing-ruo 337true YUAN Yong,SONG Quan-sheng,LIU Hong-tao,DI Chun-hui and WANG Yu-gang 336true ZHANG Yu-qing,GU Ren-ao,ZHU Jiang and CAO Pei-gen 335true XI Fen-gong,YU Hong,CHEN Xin-guo,SHI Yu-hu,CHEN Qing-xuan and ZHANG Zhi-hong 334true LI Hai-hong,YAN Shao-hua,QI De-yao and LIU Hai-ying 333true ZHOU Jun-xian and ZHOU Jun-mei 332true WANG Jun-jun and ZHUANG Yi-yi 331true YUE Jun-ming,JIAO Bao-quan,JIA Bu-nian,HU Rong-liang,JIN Ning-yi,YIN Zhen,SHI Jiang,NIE Hai-yang,HU Yun-long,WU Gang and ZHOU Zong-an 330true 2 U/L. The activity of alkaline phosphatase in serum was also detected and the recovery was 93%～95%. 5-fluorosalicyl phosphate was synthesized and used as substrate.]]> ZHAO Qi-ren,LI Mei-jia,LIU Jie,SONG Na-ling,ZHUANG Xiang-lian,CHEN Ai and LIN Han 329true QI Feng-ju,XU Qian and HUANG Yang-zhong 328true ZHOU Ping,ZENG Yun-e and DENG Yan-zhuo 327true SONG Hai-Yun,ZHANG Jing and XU Xian-Xiu 326true 125I and the characteristic of EPO receptor in BET-2 cell and G-CSF receptor in NFS-60 cell were observed by receptor ligand binding assay. It was showed that the radioactivity of ¹²⁵I-G-CSF and ¹²⁵I-EPO were much higher than that obtained by other methods and it was found that there are high and low affinity EPO receptors in BET-2 cells and one high affinity G-CSF receptor in NFS-60 cells. These results are in accord with literature data. It suggests that the two-phase iodination of chromine-T is an ideal method to iodinate cytokines.]]> CONG Yu-Wen,CHEN Jia-Pei and SHAO Yuan 325true 2SO₄ other than 0.1 mol/L NaCl to dissolve the semifinished product, Two HA forms in Na₂SO₄'s solution were found. One in staple could be absorbed by CBP, and the other in powder could be returned by fractional dilution afterwards. In 0.1 mol/L NaCl solution, HA could only be recovered by CBP absorption. It displayed staple. The recoverable rate of the method was 1.7 times than others.The physical and chemical characters of the product were analysed. It was proved that higher purity recovery and lower cost than other methods were gained.]]> LUO Man,JIANG Li-Ke and XI Jun 324true LI Zhu-Hong,LIU De-Pei and LIANG Chih-Chuan 323true in vitro, RT-PCR was used to clone KDR (Ⅰ～Ⅳ) DNA fragment from human umbilical vein EC. The cloned KDR (Ⅰ～Ⅳ) fragment was identified with enzyme digestion and sequencing and then cloned into fusion protein expression vector pGEX2T. The GST-KDR fusion proteins were expressed in E.coli XL1-blue after inducing by IPTG. The fusion proteins were extracted from bacterial inclusion body with basic denature method and purified with preparing SDS-PAGE gel followed by electric-elution.]]> SONG Shu-Mei and SHOU Cheng-Chao 322true 2+ uptake of Ca²⁺-ATPase is studied.]]> ZHOU Hong-Wei,LIN Bo-Hai,WU Wei,ZHANG You-Ling,WANG Li-Hua and MIN Xiao-Shan 321true 2^-_· was studied. The optimum conditions were investigated by examining the influence of various factors. The improved method needn't to use the luminous agent——luminol, the reagents used are cheap, both the stability and reproducibility are good, and the sensitivity is far higher than the report of other method of pyrogallol autoxidation.]]> XU Shen-Hong and HANG Hu 320true E.coli BL21(DE3). The cdb3 expression proteins were purified and its function was verified according to the ability to inhibit aldolase.]]> LI Zhi,PENG Feng,JI Chao-Neng,HUAN Chun-Lei and ZHANG Zhi-Hong 319true t₁ noise spectrum. With Watergate-NOESY and Watergate-TOCSY, the assignment of most labile protons of G,C in dsDNA fragment d(5′-TTTCGCGC)·d(3′-AAAGCGCG), which can be recognized by the transcription factor E2F, was made.]]> WU Ji-Hui,KANG Qing,XIA You-Lin and SHI Yun-Yu 318true 2. An average of 23.9% of the neurons in visual cortex is immunopositive for glycine. The densities of positive glycine neurons in the superficial stratum and deep stratum of superior collicular are 750/mm² and 781/mm² respectivelly and their percentage are 19.5% in superficial layer and 20.3% in deep layer. Glycine-immunopositive neurons of visual center include different type of cells.]]> WU Qi-Jiu and LI Jun-Feng 317true XUE Yan-Ning,DUAN Ling-Xun and R.J.POMERANTZ 316true ZHOU Bo and JING Guo-Zhong 315true 3+ labeled streptavidin. After the immunoreactions completed, the bound fraction of Eu³⁺-label is quantified by dissociating it in a fluorescence-enhancement solution and measuring its fluorescence with Wallac 1234 fluorometer. The sensitivity of the assay is 0.02 μg/L. The standard curve is linear from 0.02 μg/L to 400 μg/L. The time-resolved immunofluorometric IFN-γ assay is quick, sensitive and suitable for testing large numbers of samples, and may be useful in both industrial producing and clinical studies.]]> Erdeni,GUO Mei-Xiang,HAN Ling,QI Qi-Ge,LIU Shi-Shan,ZHANG Li-Min,CHEN Qi and ZHANG Qing-Rong 314true 3+ is linear when diluting the AP-SA 200～12 800-fold. Enzyme activity of the AP-SA is stable during two months at least.]]> ZHAO Qi-Ren,LI Mei-Jia,LIU Jie,SONG Na-Ling,ZHUANG Xiang-Lian and CHEN Ai 313true PAN Xiao-Yu,ZHAO Hui and HU Mei-Hao 312true 5 times higher than that of ELISA in S-100 antigen detection.]]> XU Ping-Xi,XIAO Hua-Sheng and JU Gong 311true Bombyx mori, 9 hours after injected by E.coli K12D31. Single-strand cDNA was synthesized by reverse transcription (RT). Partial fragments of cecropin A cDNA were obtained, cloned and sequenced, by PCR technique with a pair of degenerate primers designed according to the amino acid sequence of CM4 in Bombyx mori and cecropin A in Hyalophora. These laid a foundation for further research on preparation of the probes of cecropin A for screening the silkworm cDNA library.]]> LI Jian-Min,ZHOU Kai-Ya,ZHANG Shuang-Quan,DAI Zhu-Ying,ZHU Chang-Liang and YE Xin-Hai 310true ·NO to yield the highly fluorescent 2,3-naphthotriazole, a new fluorometric method has been reported, which combines the nitrogen gas purging system and fluorescent analysis together. The results indicated that the fluorescence intensity of the measuring solution is ^·NO concentration and acidified nitrite concentration dependent. Five acidified samples of normal human plasma have been determined and the released ^·NO is about (31.04±4.70) nmol/L. Since this method separates the sample from the measuring solution, it can avoid the interference from the sample to the fluorescence analysis so that it can be used to measure biological sample and continuously observe the ^·NO releasing.]]> TIAN Ya-Ping,SHEN Wen-Mei and W.H.BETTS 309true Gγ- and ^Aγ- globin gene promoter regions of 4 previously identified mutants were amplified by nested PCR, then the mutations were detected by CCM, and the optimal condition was determined. It was proved that CCM is a simple and reliable molecular diagnostic method for the detection of nd HPFH point mutations.]]> LIU Jian-Wei and XU Xiang-Min 308true 2O₂-treated HL-60 cells in different ways were reported.The 8-hydroxyguanine in the cells treated in more than 0.4 mmol/L H₂O₂ for eight hours.In order to identify the 8-hydroxyguanine, the result was confirmed by CGC/MS-SIM. The results suggested that the nuclear DNA damage in cells caused by H₂O₂ may be involved in formation of hydroxyl radicals.]]> ZHANG Hai-Tao,ZHU Qi-Feng,MO Li-Er,ZHUANG Hai-Qi and Cai Chun 307true 2 was transformed into BL₂₁ host E.coli and expressed by IPTG induction for 4 hour, The expressed protein (14.4 ku) was purified by His-Bind^TM Sephorose colum and SDS-PAGE, thus providing the basis for the selection of the eNOS-specific inhibiting peptides and the preparation of the specific antibody against eNOS.]]> ZHAO Jian-Hua,SHEN Yue,ZHU Min-Sheng,XU Xiang-Yu and PAN Ying 306true WANG Jin,CHEN Guang-Chun and LU Jian 305true ZHAN Feng-Huang,JIANG Ning,CAO Li,DENG Long-Wen,ZHOU Ming,XIE Yi,ZENG Zhao-Yang and LI Gui-Yuan 304true in situ refolding on column were investigated. Three refolding approaches were adopted: dialysis, in situ refolding via metal chelated chromatography and via gel filtration chromatography. The relative refolding index and relative recovery of the ScFv inclusion body were compared using the three procedures. The results showed that the refolding on gel filtration column(sephacryl S-200) was far more efficient than the other two approaches, with relative refolding index of 98% and relative recovery of 81%, illustrating the potential of this technique in production of recombinant ScFv.]]> ZHU Ying-Chun,WANG Yan,GAO Rong-Kai,LIU Qun-Ying,HUA Bing and CHEN Yu-Ping 303true TIAN Xue-Jun,SHOU Cheng-Chao,MENG Lin and DONG Zhi-Wei 302true YANG Zi-Yi,WANG Xin,DONG Jia-Xin,YAO Zhi-Jian and SHEN Bei-Fen 301true CHEN Hui-Peng,FAN Guo-Cai,FU Wei,CHEN Ji-Zhong,JIANG Zhong-Hua and ZHANG Qiang 300true XU Xiang-Rong,WANG Wen-Hua and LI Hua-Bin 299true 5 U/mg.Morcover, it can coordinate with the granule-macrophage stimulating facet (GM-SCF) to stimulate proliferate of the CFU-GM from the human bone marrow. The acquiration of the rhSCF is important to both the labotory research and the clinical therapy.]]> LAI Chun-Ning,ZHU Yuan-Xiao,SHEN Bei-Fen and HONG Hai-Yan 298true 2+ and 55℃ annealing temperature are adopted. The other two factors affecting reliability are quantity of the extract and contamination of the positive DNA fragments in the reaction.]]> GU Shao-Hua,JIANG Guang-Ping,CAO Gen-Tao,SHENG Ji-Qun,LIU Jian-Ping,DAI Jian-Liang,LIN Qing,LIN Yuan,LI Shi-Zhong,LIU Wei-Ping and XIE Yi 297true 2O-TFA” elution system is applied in purification and analysis of human glycoalbumin fragment including the region of lysine 525, which was synthesized by different methods. The peptide fragment of albumin KQTALYYC prepared by acid-labile PEG resin was glycosylated and purified by gel filtration and analysed by RP-HPLC. A single peak demonstrated that the glycosylation of the peptide was successful. Heptapeptide fragment of albumin QTALYYC was synthesized by chloromethyl resin according to the Boc chemistry strategy. The pure heptapeptide was obtained by semi-preparative RP-HPLC. Glycosylated lysine was purified by gel filtration and ascertained by RP-HPLC. The heptapeptide was coupled with glycosylated lysine. RP-HPLC of the product showed that the glycopeptide is qualified as a semiantigen.]]> LIANG Xun,LI Shun-Zi and LI Wen-Lan 296true 2＋-ATP could be dissipated by the proton ionophore CCCP, and inhibited by the proton transport inhibitor DCCD; it was also found that the plasma membrane H^＋-ATPase specific inhibitor vanadate could quench the fluorescence completely. The fluorescene quenching was Mg²⁺-dependent, K^＋-stimulated, with an optimum pH of 6.5. All the above results indicated that the fluorescence quenching was caused by the transport of protons by the plasma membrane H^＋-ATPase. It was also suggested that the maintaining of suitable conformation of the plasma membrane H^＋-ATPase,and the tightness of plasma membrane vescials are the two key factors for the proton transport determination.]]> QIU Quan-Sheng and SU Xue-Feng 295true SfiⅠ and NotⅠ and ligated into the phagemid pCANTAB5E. The recombinant DNA was introduced into E.coli TG1 by electroporation, and 5.3×10⁷ phage was harvested. The insert was present in 66.7% of phage,thus the random deca-peptide library had a complexity of 3.53×10⁷.The titer of phage supernatant was 4.8×10¹¹ after the helper phage M13KO7 super-infection. This library was screened using angiogenin protein. 26 ANG-binding clones were indentified from 94 enriched individual phagemid clones after two rounds of panning, The nucleotide sequences encoding peptide recombined in 12 positive phagemid clones were determined. ELISA showed that all of them could specifically bind to ANG.]]> YANG Hui,ZHANG Ying-Qi,HAN Wei,YAN Zhen,YAO Li-Bo and SU Cheng-Zhi 294true ZHAO Cong-Jian,JIA Yu-Feng,DING Qin-Xue,QUE Hai-Ping,LIU Shao-Jun and GUO Yao-Jun 293true CHEN Jun-Song and SONG Jian-Guo 292true 2+. These small fragments were successfully re-assembled to form full genes with original size by one round of PCR without any external primers and two other rounds of normal PCR amplification. This shuffling protocol may help to construct chimera genes from a family of genes with high sequence homology.]]> ZHOU Jia-Hai and CHEN Hai-Bao 291true 125I with chloramines-T methods and purified by the Sephadex-G25 chromatograph column. The reaction between antigen and antibody was carried out by one step balance method and incubated in 4℃ for 24 hours, then separated bond and free antigen by PR reagent. The detection range of this method was about 0.1～3.2 μg/L, the lowest detection level was 0.1 μg/L, error within batches and between batches was less than 6.4% and 10% respectively. The serum IL-6 concentration in normal male was (0.270±0.13) μg/L (n=115), and in female was (0.260±0.10) μg/L (n=101), there was no difference in male and female group. Otherwise, the level of IL-6 in serum of rabbits was significantly higher than that of self-control at 24 hours after hemorrhagic shock and reperfusion. IL-6 in lymph fluid of rat after hemorrhagic shock was significantly elevated, then it was descended by the treatment of anisodamime (1 mg/kg). The liberation of IL-6 also was promoted and obviously higher than that of the control when fibre cells around tooth were cultured with endotoxin (10 mg/L) at different time in vitro.]]> YAN Guang-Tao,HAO Xiu-Hua and WANG Lu-Huan 290true LIU Hong and CHEN Lan-Ying 289true －1. Levels of hydrogen peroxide in leaves of some plant species ranged from 0.1～0.8 μmol·g^－1.]]> LIU Jun,Lü Bo and XU Lang-Lai 288true Undaria pinnatifida were soaked by CaCl₂ solution with different concentration and time at 4℃, the effect of CaCl₂ solution on efficiency and influorescence emission spectra of chloroplasts were examined. The results show that the efficiency of collected chloroplasts is increased markedly after soaking in CaCl₂ solution. According to the results of collected efficiency and characteristic of influorescence emission spectra at room temperature of chloroplasts, it was suggested that soaking in the 0.2 mol/L CaCl₂ solution for 10 min is optimum. Under this condition, the efficiency of collected chloroplasts is as 5 fold as control group, and the characteristics of chloroplasts obtained by CaCl₂ soaking are similar to that of traditional method.]]> LI Ai-Fen,CHEN Min and ZHOU Bai-Cheng 287true YIN Wen-Xuan,LIU De-Pei,LI Zhu-Hong and LIANG Zhi-Quan 286true Rhodiola algida Var.tangutica collected from Qinghai plateau(altitude:4 000 m),on solid and in liquid culture medium(MS+BA₂+NAA_0.2)respectivelly,was successful.After cold (4～5℃)acclimation or ABA treatment for 10 or 14 days, the freezing resistance of suspension cells was increased. Proteins from the liquid suspension cell culture medium exhibited antifreeze activity. Treatment of the antifreeze proteins(AFPs) with boiling or trypsin caused inactivation,proving the protein characteristics of AFPs.Periodate and borate inhibited the antifreeze activity of AFPs,suggesting the presence of carbohydrate. Of the four treatments(25℃;25℃+ABA;5℃;5℃+ABA),2～3 polypeptides(29～50 ku) could be detected from the one dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis（SDS-PAGE）. PAS(periodic acid-schift’s reagent) reaction of SDS-PAGE showed the presence of carbohydrate in the polypeptides.]]> LU Cun-Fu,JIAN Ling-Cheng and KUANG Ting-Yun 285true ZHOU Jun-Yi and LUO Chao-Quan 284true HaeⅢ-digests of random chickens’DNA. Therefore, RAPD products that are highly variable among individuals can be used as DNA fingerprinting probes.]]> YANG Shao-Qing and MENG An-Ming 283true 32P labeled or non-labeled SPP. The SPP level was determined based on competitive binding of SPP or ³²P-SPP to HEK cells. This method does not require special apparatus, and able to measure the content of SPP as low as pmol with high sensitivity and good repetition. The between groups deviation was less than 15%.]]> TU Zhen-Xing,GONG Yan-Fang,J.R.van BROCKLYN and S.SPIEGEL 282true in vitro and formed RNA step ladders from 70 nt to 706 nt, which indicates that the self-cleavage ribozyme transcripts can be used as RNA molecular mass markers.]]> DENG Wen-Sheng,YANG Xi-Cai,KANG Liang-Yi,ZHANG Feng-Xue and FU Lin-Chun 281true 2+, concentration of DMSO, denature time, annealing temperature, elongation time, number of cycles based on Uniform Design was reported. The results show that a set of PCR conditions with specific, high yield amplified product can be obtained for purified template or simple-treated template by 6～10 times of optimization experiment. The Uniform Design is useful for the optimization of PCR conditions.]]> ZHU Bin,WANG Guo-Quan and CHEN Jian 280true in vitro to obtain the RNA-CRS. The hSCF RNA-CRS with a 110 bp deletion from base 499 to 608 in hSCF cDNA was identified by DNA sequencing and it is suitable to be used as a reliable RNA-CRS for the quantitation of the transcriptional expression level of recombinant hSCF in eukaryotic cells by quantitative RT-PCR.]]> TAN Wen-Bin,NIE Yi-Ling,LUO Sai-Qun,GUO Xiao-Shan,CHENG Guang-Jie,CHEN Han-Chun and ZHU Ding-Er 279true E.coli BL21(DE3) and expressed induced by IPTG. Most of the expressed CK2β proteins were insoluble. From 6 L(about 10.4 g) bacteria, 20 mg soluble protein was extracted from the insoluble pellet and purified by a single step P11 phosphocellulose chromatography, the yield of purified CK2β subunit was 6.8 mg. SDS-PAGE analysis of the purified protein showed only one band with molecular mass of 26 ku. Western blot analysis confirmed that the expressed product was human CK2β subunit. Addtion of the CK2β subunit to CK2α subunit led to maximum stimulation at a 1∶1 molar ratio of both subunits. These results demonstrated strongly that the cloned, expressed and purified recombinant protein was human CK2β subunit. The large amount of purified recombinant CK2β protein lays solid basis for further study directly the characteristics of the enzyme and the relationship of structure and function between CK2β subunit and its interacted proteins.]]> LIU Xin-Guang,LIANG Nian-Ci and MA Jian-Quan 278true 32P］dCTP labeled first strand cDNA as probes.]]> GOU De-Ming,LI Wen-Xin,JIANG Da-He and HUANG Jian 277true KANG Bin and TONG Zhe 276true EcoRⅠ.The results showed that Northwestern blot with some modifications is a useful method for isolation of expression clones of genes encoding RNA-binding proteins.]]> DENG Qing-Li,HUANG Zhi-Ming,SHAO Jing and HUANG Zhi-Qing 275true 2 to generate singlet oxygen ( ¹O₂) under illumination. ¹O₂ reacts with histidine or imidazole to form intermediate products which oxidize RNO. The reaction causes optical absorption of RNO at 440 nm to decrease. It is named the bleaching of RNO. Bleaching of RNO is increased with the increasing of RB illuminated time, which shows that the production of ¹O₂ has grown in the reaction. Bleaching of RNO is promoted by the rising of the concentration of histidine or imidazole. Imidazole plays more evident role in the reaction than histidine does. Bleaching of RNO is decreased by the presence of ¹O₂ quencher NaN₃ or DABCO. ¹O₂ in lettuce thylakoids has been detected by the reaction in strong light. The production of ¹O₂ grows with the increasing of light intensity and illuminated time in lettuce thylakoids.]]> XU Zhi-Fang,LUO Guang-Hua,WANG Ai-Guo and CHEN Yi-Zhu 274true SONG Yang,HOU Si,ZHAO Hui,WANG Rong-Hai and WU Zhong-Hua 273true TM cDNA expression array and there are 11 genes expressed much higher in nasopharynx than in other tissues .These genes might be candidates for relative tissue specific genes of nasopharynx. The expression result was further confirmed by RT-PCR examination.]]> ZHANG Ling,LING Jian-Hua,HE Zhi-Wei and YAO Kai-Tai 272true FAN Heng-Yu,TONG Chao,LI Man-Yu and SUN Qing-Yuan 271true ZHOU Hui,LI Xian-Feng,LI Yin-Mei,LOU Li-Ren and YUE Jia-Chang 270true Bacillus thuringensis expressed in E.coli transformed with pQEBt was purified by Ni-NTA affinity chromotography. One phage (PH5) that binds specifically to Bt protein was selected from a combinatorial library of random 7-mer peptides fused to minor coat protein (pⅢ) gene of the filamentous coliphage M13 through three cycles of biopanning and ELISA analysis. A new method of recombination phage aided detection of insecticidal Bt protein in transgenic plants was developed using PH5. The phages selected should also be useful in the structure study of functional domains of Bt insecticidal proteins.]]> LI Li-Hong,LI Chang-Qing,HUANG Xiu-Li and TIAN Ying-Chuan 269true in vitro and in vivo. Here a protocol for effective excision of neo gene located on chromosome of Salmonella have been developed. In order to establish a tetracycline-induced expression system in the attenuated Salmonella typhi CVD908 strain, a fused DNA fragment consisting of genes of tetracycline repressor (tetR) as well as neo gene flaked by two loxP sequences in same orientation has been integrated into a defined Δaro C locus of CVD908 strain via homologous recombination. To excise the neo gene from the locus, the suicide plasmid pJG9/Cre expressing Cre recombinase under the control of tetracycline response promoter PL_tetO-1 was constructed and electropolated into the CVD908 strain. The expression of the Cre recombinase induced by anhydrotetracycline successfully excised the neo gene. Since the suicide plasmid contains SacB gene encoding an enzyme that is lethal to G- bacteria in the presence of sucrose, growing of the bacteria in a medium containing 10% sucrose cured the pJG9/Cre plasmid. Both antibiotic and PCR identification demonstrated the successful excision.]]> QIAN Feng,PAN Wei-Qing and DU Jing-Ling 268true 2. This procedure was simple, time-saving, high sensitivity and reproducible. Based on the improved procedure, the differential gene expression were studied between immature siliques of Arabidopsis wide-type and ast mutant. From nearly 16 000 cDNA fragments analyzed, 28 differential cDNA fragments were screened. After the second PCR amplification, 13 differential cDNA fragments were identified among which 7 fragments were wild type specific and 6 fragments were ast mutant specific.]]> MAO Ai-Jun,WANG Tai and SONG Yan-Ru 267true in vivo rapidly, a new approach was introduced by using INDIA^TM phosphorylated protein probe. Eight phosphoprotein bands were detected by this method in the thylakoid membranes isolated from pea leaf discs illuminated at 400 μmol·m^-2·s^-1. The molecular masses of those phosphoproteins were 65 ku, 45 ku, 36 ku, 33 ku, 30 ku, 29 ku, 20 ku and 10 ku. Respectively by using various polyclonal antibodies, those phosphoprotein bands were identified as phosphorylated D1/ phosphorylated D2 dimer, PSⅡ core phosphoproteins, CP43 (45 ku), D2 (36 ku), D1 (33 ku) and psbH gene product (10 ku), and the light-harvesting complex (LHCⅡ) phosphopolypeptides, LHCB1 (30 ku) and LHCB2 (29 ku). A comparison was made between this new approach with other methods of detecting phosphoprotein such as radiolabeling experiment or immunological blot using phosphothreonine antibody.]]> LI Jiong and DU Lin-Fang 266true WANG Yan,JIAO Hong-Li,ZHANG Jin-Zhu and HE Rong-Qiao 265true GUO Yong-Sheng,WANG Jie,DONG Jun and SONG Xi-Jin 264true Agkistrodon acutus from Hunan Province, and was reversely transcribed to cDNA. Then by applying the touchdown method to anchored-PCR, with only one specific and one universal primer, two relatively distinct bands were amplified in a single non-nested PCR reaction of no more than 30 cycles. Cloning and sequencing indicated that the sequence is homologous with other members of the C-type lectin superfamily in snake. High level fusion expression in E.coli was achieved, with the fusion protein accounting for 26%～30% of total proteins.]]> ZHA Xiang-Dong,ZHANG Hua-Yuan,XIAO Ya-Zhong,LIU Jing and XU Kang-Sen 263true TAN Wen-Bin,ZHU Min,NIE Yi-Ling,LUO Sai-Qun,CHENG Guang-Jie,HU Wei-Xin and PENG Xing-Hua 262true PEI Wu-Hong,SHU Cui-Ling,CHEN Xing,XIA Guo-Wei,LI Song and SHEN Bei-Fen 261true CHEN Ran,JIN Zhe,WU Di,TANG Rong and MAO Yu-Min 260true HUANG Yao-Jiang,LI Yan,SHI Ming,WANG Jian-An,Hu Mei-Ru and SHEN Bei-Fen 259true YAN Wen-Sheng,JIANG Yong,HUANG Qiao-Bing and ZHAO Ke-Sen 258true LAN Yan,QIAN Xiao-Hong,WANG Ge,LI Yong,LUO Ling,LIU Zheng-Liang and HE Fu-Chu 257true SUN Huan-Dong,ZHANG Cheng-Gang and HE Fu-Chu 256true I/M_r calibration, analysis results report and database query, were reported and discussed.]]> JIA Yu-Feng,LIN Qiu-Xia,GUO Yao-Jun,GUO Yao and LIU Shao-Jun 255true －) has been made. In this system, the effect of some antioxidants for scavenging ONOO^－ was tested. The constitute of this system and the program of starting were followed as: The ozone (O₃) was bubbled through a glass-frit into 10 ml 0.01 mol/L solution of sodium azide in CB(pH 10.5) to generate ONOO^－. The 800 μl ozonized solution of azide was injected into a glass tude in situ which contains 100 μl sample and 100 μl luminol solutions to initiate chemiluminescence (CL). The pluses / 6 seconds (CP6S) were determined immediately and continually for 10～30 times. A certain CL intensity (CP6S) was chosen as evaluation index to compare the activity of antioxidants. This chemiluminescent system is sensible, simple and stable. The determination limit was 8.74 μmol/L ONOO^－. The linear rang was 8.74～74.04 μmol/L ONOO^－. The intra batch and inter batch variation coefficient (CV%) of the analysis were 3.35%(n=10) and 5.52%(n=10) respectively. It was tested that Vit.C, teapolyphenol, procyanidin and thiourea all have effects on scavenging ONOO^－.]]> FAN Xiao-Bing,SHA Da-Nian,LIANG Xiao-Feng,HAN Chao and HU Tian-Xi 254true MseⅠ primers were fluorescent labeled for auto-sequencer. PCR reagents and primers and adapters of MseⅠ and EcoRⅠ, which were synthesized, the AFLP protocol has been modified, and reaction and electrophoresis conditions were optimized, the results obtained can be comparable to that of AFLP fluorescent labeled AFLP kits with less cost.]]> YANG Kai,SONG Wan,ZHANG Chun-Qing and JIA Ji-Zeng 253true E.coli, the difference is very obvious. Among different mycobacterium, BCG has the highest light production and mycobacterium tuberculosis has the lowest light production. The sensitivity of Phage 88 is higher than Phage 40, the difference is obviously. It can be considered that both recombinant mycobacteriaphages can detect mycobacterium specifically, but Phage 88 is more suitable for clinical usage.]]> Lü Bin,XU Shun-Qing,FU Zhi-Jun,CHEN Zhi-Fei,LI Kai-Chang and ZHOU Yi-Kai 252true WEN Si-Yuan,WANG Xiao-Hong,LIN Li,GUAN Wei and WANG Sheng-Qi 251true CV) within same sample was 9.6% and the radioactivity remains stable after 72 hours if use NaOH as trap agent. It is significantly stable than use phenylethylamine as trap agent, which the CV was 31.9% and the radioactivity decreased 47% within the first hour and decreased to background after 6 hours. The reabsorption experiment shows over 80% of ¹⁴CO₂ can be reabsorption by NaOH within 6 hours. It is suggested that NaOH is a much better trap agent than phenylethylamine and the sensitivity can increase 1.66 folds. Using this method the GAD activity in 0.39～17.8 mg of brain tissue can be measured and it is success in determine the GAD activity both in rat brain tissue and cultured neurons.]]> HU Yuan-Yuan and HE Shan-Shu 250true ZHU Bin,JIN Fen-Xiang,ZHAO Jian-Long,SUN Yue,CHEN Ji-Feng,ZHAO Xin-Tai and XU Yuan-Sen 249true P＜0.01). The nude mouse, 6 weeks of age, was injected s.c. with a single dose of 3×10⁶ infected tumor cells. The GFP fluorescence was directly exited by 488 nm argon ion laser and recorded by digital camera with 530 nm long pass filter.]]> JIN Ying and XING Da 248true in silicon sequence elongation technique, 5′-RACE and 3′-RACE technique, the full-length cDNA sequence of human neuroglobin was successfully obtained (GenBank accession number AF422797). The cDNA sequence of human NGB is 1 909 bp in size and capable of encoding a protein of 151 amino acids. The 5′-untranslated region is 375 bp, while the 3′-untranslated region is 1 078 bp including 27 bp of poly(A) sequence. Results demonstrated that the RACE technique coupled with electronic sequence elongation technique is useful to obtain unknown sequence of 5′-terminal or 3′-terminal part of a new gene.]]> WANG Chun-Li and ZHANG Cheng-Gang 247true LIU Yan,ZHOU Jian,LIU Xin-Ping,YAO Li-Bo,WANG Ji-Cun,SU Jing-Kuan and HUI Yan-Nian 246true Ⅱbβ₃ is a calcium-dependent heterodimeric protein on platelet, and its extracellular part can bind to RGD containing ligands. Here, a type of sensor prepared by transferring NTA-DOGS containing lipid monolayer to a 50 nm thick gold layer deposited on glass slide is reported. The surface binding ability and regeneration of the sensor were characterized by using a synthetic polypeptide P1 containing six histidine and RGD ligand. The specific binding of integrin to RGD ligand and the effect of divalent cations were investigated. The results show that His-tagged protein can be immobilized on the NTA sensor surface with a functional orientation and the results also show that removing of Ca²⁺ bound on low affinity sites or adding of Mn²⁺ can increase the binding ability of integrin.]]> LU Ying-Jie,ZHANG Fan and SUI Sen-Fang 245true 35S-ACaM2 was producted by using ³⁵S-labeled amino acid mixture in E.coli. SDS-PAGE and autoradiograph indicated that high-purified, high-specific radioactivity ³⁵S-ACaM2 was obtained.Electrophoresis character of ³⁵S-ACaM2 is the same as that of unlabeled ACaM2 with Ca²⁺ or EGTA. Dot-blot and NC overlay experiment showed that ³⁵S-ACaM2 could be used to detect calmodulin-binding proteins as a sensitive probe.]]> CUI Su-Juan,GUO Xiao-Qiang,MAO Guo-Hong,ZHAO Jun-Feng,SUN Ying,BAI Juan,MA Li-Geng and SUN Da-Ye 244true ZENG Zhao-Yang,XIONG Wei,SHEN Shou-Rong,ZHU Shi-Guo,LI Xiao-Ling,LI Wei-Fang,LI Jiang,ZHOU Ming,FAN Song-Qing,MA Jian,ZHOU Jie,XIAO Bing-Yi,HE Lin and LI Gui-Yuan 243true HU Yuan-Yuan,ZHOU Xin-Wen,HE Shan-Shu and WANG Jian-Zhi 242true DING Ya-Ping,CHEN Li-Yan,ZHANG Wen,CAO Heng-Jie,NI Shi-Ming,ZHOU Mei-Fen,LIANG Hao,LING Zhi-Guang,GENG Yong-Yao and WANG Sheng-Qi 241true H/κ of an anti-tumor antibody AA98 was refolded in vitro by dilution refolding, gel filtration chromatography and urea gradient gel filtration, respectively. Concerning various factors in the renaturing buffer, such as GSH/GSSG ratio, arginine concentration, pH, flow rate, protein concentration in denaturing buffer and linear gradient, a urea gradient gel filtration method for V_H/κ refolding was established. As a result, compared with the traditional dilution refolding and gel filtration, the activity recovery of V_H/κ obtained by urea gradient gel filtration was significantly improved.]]> ZHANG Zhi-Qiang,LIN Yun and YAN Xi-Yun 240true ZHOU Hao,DU Lin-Fang and ZHU Xiao-Feng 239true DONG Yan,ZHANG Feng,MEI Zhu-Zhong,LIU Bin and SUN Zhi-Xian 238true GAO Zhi-Xian,CHAO Fu-Huan,WANG Hong-Yong,FANG Yan-Jun,NING Bao-An,PAN Hai-Feng and ZHU Hui-Zhong 237true PEI Li,DENG Hua,ZHANG Li-Jun,JIANG Cheng-Tao,ZHAO Xing-Chun,CHANG Cai-Qin and WANG Jian 236true ZHENG Fang,ZHOU Xin,YAN Ming,YE Shui-Qing and LIU Fang 235true sfiⅠB site) while the SMART oligonucleotide (contained sfiⅠA site) was utilized as a template so that the first-strand cDNA could be extended over the 5′end of mRNA. The double-strand cDNA was amplified by LD-PCR(long-distance PCR) with the above two primers and then digested by sfiⅠ(ⅠA & ⅠB) restriction enzyme.After cDNA size fractionation through CHROMASPIN column,the double-strand cDNA was ligated into the sfiⅠ-digested λTripIEx2 vector and then the recombinant DNA was packaged in vitro. The unamplified human embryo nasopharynx cDNA library consists of 1.0×10⁶ independent clones in which the percentage of recombinant clones is about 96%.The titer of the amplified cDNA library is 7.8×10⁹ pfu/ml and the average exogenous inserts of the recombinants is 1.2 kb.The full-length cDNA of NAG4, a candidate tumor suppressor gene related with nasopharyngeal carcinoma, was amplified in the cDNA library by PCR. These results show that the human embryo nasopharynx cDNA library has an excellent quality and lays solid foundation for screening and cloning new tumor suppressor genes of nasopharyngeal carcinoma and tissue-specific genes of human nasopharynx.]]> ZHANG Bi-Cheng,CAO Li,QIAN Jun,YU Ying,LI Wei-Fang,XIANG Juan-Juan and LI Gui-Yuan 234true Pichia pastoris is a system to express a lot of foreign proteins, however the expression levels of transformants vary widely from one to one clone. In situ two-film method is a rapid method based on immunology to screen Pichia pastoris transformants expressing high-level protein, in which yeast colonies are lifted from solid culture onto a cellulose acetate film. Then a nitrocellulose film is used to capture the secreted proteins that pass through the cellulose acetate film. The proteins binding on the nitrocellulose film are stained by immunology methods. Pichia pastoris transformants expressing high-level hFL are abtained by using this method, and the expression level in liquid culture is about 20 mg/L. The result of ELISA shows that the staining intensity is correlated to the expression level in liquid culture. Western blot of culture supernatant shows obvious band at 25 ku, while the control doesn't show any band. The expression quantity increases as the inducing time increases.]]> ZHANG Yan-Li,CHEN Song-Sen,YANG Ke-Gong,Di Xu,XIONG An-Qi and ZHANG You-Hong 233true XIE Wen-Zhang,WANG Dong,DU Hong-Wu and CHENG Jing 232true Oryza sativa indica 4^th chromosome has been sequenced by this method, the GenBank Accession number: AL512542.]]> TANG Ye-Sheng,LI Ying,ZHU Jing-Jie,HU Xin,LIN Zhi-Xin,HAN Bin and HONG Guo-Fan 231true MA Shu-Hua and WANG Sheng-Qi 230true YAN Gui-Hong,XING Da and TAN Shi-Ci 229true Saccharomyces cerevisiae by means of PCR without any prior DNA extraction and purification steps. This method involves a simple boiling step for 2～5 min of whole yeast cells suspended in water. Both the fresh and frozen competent S.cerevisiae cells can be used for transformation. The method of storing the competent yeast cells at －80℃ for future use is convenient and economic. A skill of decreasing the dimer products and increasing the specificity of PCR is recommended.]]> YE Ling,LIU Jian-Wei and LIU Jing 228true in vivo, as well as the role of histone modifications in gene regulation. A simple ChIP protocol is established and used to study the H3 acetylation pattern of the β-globin locus in MEL cells. DMSO induction results in a dramatic increase in H3 acetylation at hypersensitive site HS2 and active gene (βmaj) promoter, whereas the inactive gene (Ey) promoter maintains low acetylation. This result indicates that the ChIP method is feasible.]]> FU Xiang-Hui,LIU De-Pei,XIN Li,HAO De-Long,DONG Wen-Ji,HUANG Yue and LIANG Chih-Chuan 227true 6f complex, the light-harvesting complexes and the RubisCO are well resolved. Analysis of chloroplast protein on a second gel dimension allows seperation of more than 50 different proteins which are part of multi-subunit enzymes. Western blotting analysis was also used to confirm the identity of the complex. The method has been used to analyze protein complexes of grana and stromal thylakoid.]]> LI Bei-Bei,GUO Jin-Kui,ZHOU Yun,ZHANG Zhu-Zhu and ZHANG Li-Xin 226true Chlamydia trachomatis DNA，plasmid containing the sequence of interest was constructed for the standardization of the method and to assess its sensitivity. Primers and MGB probe were chosen in the conserved region of cryptic plasmid pLGV440. The Results showed that this Chlamydia trachomatis assay had a threshold sensitivity of one genome copy number per reaction. A linear standard curve was obtained between 10⁰ and 10⁹ DNA copies/reaction (r＞0.990). Fifty clinical specimens were tested by real-time PCR and LCR simultaneously and the coherence was 100%. These observations suggested that real-time PCR based on MGB probe was an excellent candidate for a standard Chlamydia trachomatis detection method in a large scale.]]> ZHAO Jin-Rong,BAI Yu-Jie,WANG Sheng-Chun,GUO Yan-Hai,ZHANG Qing-Hua,ZHANG Ju and YAN Xiao-Jun 225true Sulfolobus shibatae was crystallized. The crystals could only diffract to 0.65 nm. And gel medium was used to improve the diffraction resolution. Gel adding led to slower speed of crystallization, change of crystal morphology and shortening of C axis of unit cell. The crystals grown in gel medium could diffract to 0.35 nm, and a set of data was collected.]]> WANG Gang-Gang,YANG Hai-Tao and RAO Zi-He 224true in vitro for establishing standard curves. The result shows that constructed cRNA curve has a wide linear range of at least six orders and correlation coefficient is 0.99.The rapid and simple method can be applicable to measurement of transcripts for any gene.]]> Zhang Yan and Shen Qian 223true 13C labeling experiments and analyzing the labeling patterns of cellular amino acids by two-dimensional ［¹H-¹³C］ nuclear magnetic resonance spectroscopy was developed. The software package was constructed with a comprehensive and improved isotopomer model, which introduce the concept of Reaction Mapping Matrices(RMM). Thus with a simplified algorithm, the platform is established for quantitating the intracellular flux distribution and investigating the cellular metabolism more efficiently. The metabolic model includes the Embden-Meyerhof-Parnas, the pentose phosphate pathway, the tricarboxylic acid cycle, anaplerotic reaction sequences, some fermentative pathway and pathways involved in amino acid synthesis.]]> ZHANG Hui-Min,ZHU Jiang-Feng,KAZUYUKI SHIMIZU and YAO Shan-Jing 222true YU Wei-Dong,YANG Li-Xin,LI Wen-Yong,LIU Gui-Sheng and CHEN Qing-Xuan 221true ZHAN Lin-Sheng,SHAO Ning-Sheng,PENG Jian-Chun,SUN Hong-Yan and WANG Quan-Li 220true in situ expression of the genes in large numbers of cultured cells, a high-throughput technique was established. A novel method of constructing the cell microarrays was devised and the cell microarrays including 100 spot arrays of mixture of the graft cells and paraffin from 20 kinds of cell lines was made successfully. Expression of P53, P21, PTEN and P16 protein in the cell microarrays was detected by immunohistochemistry. Meanwhile, expression of BRD7 and NGX6 mRNA in the cell microarrays was estimated by in situ hybridization. In situ expression profiles of P53, P21, PTEN, P16 protein and BRD7, NGX6 mRNA in different kinds of cultured cells were established. The cell microarrays provided a new high-throughput tool for biological function studies of the genes. The cell microarrays could be widely used the in situ analysis of the gene expression at the DNA, RNA, and protein level. In additional, the cell microarrays could also be applied to estimate drug target validations.]]> FAN Song-Qing,XIAO Bing-Yi,CAO Li,XIONG Wei,OUYANG-Jue,TAN Chen,LI Wei-Fang,TANG Ke and LI Gui-Yuan 219true IL6, IFτ, CX43, PSMC3, oct4, DNMT1. The results were same as those obtained by using conventional RT-PCR strategies. Further it forth the first time reported the expression of DNMT1 and PSMC3 gene in bovine oocytes.]]> LI Yan-Xin,LI Shi-Jie,ZHAO Ding-Sheng,ZHAO Chun-Jiang,DU Wei-Hua,DAI Yun-Ping and LI Ning 218true Klebsiella pneumoniae (Kp) capsule glycoprotein. The rabbit antiserum of Klebsiella pneumoniae capsule glycoprotein was prepared successfully by using a purified Kp capsule glycoprotein as antigen and the antibody was purified with ammonium sulfate fractionation and adsorption. The sensitivity of the assay is 0.031 mg/L. The standard curve is linear from 2.5 mg/L to 30 mg/L. The error of inter-plate is from 1.04% to 3.22%, and the error of intra-plate is from 2.61% to 8.35%.]]> LI Qing-Zhou,ZHANG Yan,QI Wei and DU Lian-Xiang 217true LIU Jin-Feng,XING Da,SHEN Xing-Yan and ZHU De-Bin 216true Spirulina platensis and red alga Polysiphonia urceolata respectively. Both sodium periodate and glutaraldehyde are effective coupling agents being capable of constructing the R-phycoerythrin-C-phycocyanin conjugate, which was also called phycobiliproteins energy transfer model. The two artificial conjugates constructed with different methods were purified by Sephadex G-200 chromatography respectively. Spectra analysis indicated that energy transfer occurred in the two conjugates. The conjugate with sodium periodate had the higher efficiency of energy transfer than that with glutaraldehyde conjugate.]]> WANG Guang-Ce,MA Sheng-Yuan and ZENG Cheng-Kui 215true LIU Jing,ZHUANG Gui-Sheng,XU Liang-Ji,JIA Chun-Ping,JIN Qing-Hui and ZHAO Jian-Long 214true 2+ were included in the extraction buffer. Plant tissues were lysed in the extraction buffer, then ribonucleases (RNAses) and other proteins were denatured and extracted by phenol/chloroform. After that, the DNA was selectively fractionated from RNA with sodium acetate (NaAc) (pH 5.6). The isolated RNA with this method gave good yield. Results of non-denaturing electrophoresis or formaldehyde agarose gel electrophoresis both showed higher amount of 25 S ribosomal RNA (rRNA) than that of 18 S rRNA. Northern hybridization gave sharp and clear signals. Both plastid gene and nuclear gene were amplified successfully by RT-PCR. These results show that, the RNAs isolated with this method are in good integrity and purity, and can meet the needs of most molecular biological experiments including gene cloning and expression analysis. In this method, phenol/chloroform were used to remove proteins and inactivate RNAses, NaAc (pH 5.6) was used to precipitate RNAs, thus largely reduced the experimental expenses.]]> ZHANG Nian-Hui,WEI Zhen-Quan,HE Jun-Xian,DU Lin-Fang and LIANG Hou-Guo 213true Agrobacterium sp. binary vector system for high-throughput functional analysis of genes in plants has been produced, but a bottleneck problem using this system for fast and reliable DNA cloning is how to obtain entry clones for the PCR products or other DNA fragments simply, economically and efficiently. To address this problem, the traditional TA cloning and the Gateway recombinant cloning techniques are integrated, and two kinds of TA cloning vectors compatible with the Gateway cloning are constructed. The vectors can be used for cloning PCR products or other DNA fragments and at the same time making entry clones in a simple, economical and efficient way.]]> CHEN Qi-Jun,AN Rui,ZHOU Hai-Meng,CHEN Jia and WANG Xue-Chen 212true 0) proportionally, the slope of standard curve remains invariable, suggesting that the slope is independent of actual copy numbers of RNA standard. Therefore, anyone of tested RNA (cDNA) samples could be used after serial dilution as RNA standards to obtain slope. Compared with absolute quantitative method, the present one appears to have a more excellent consistency (difference less than 4%) in the relative expression indices with absolute quantitative method, than traditional relative method 2-ΔΔCT (difference more than 5%). The results show that the method described here is simple, precise and cost-effective for relative quantifying gene expression.]]> ZHANG Chi-Yu,XU Shun-Gao and HUANG Xin-Xiang 211true 95%). The vector p3.1-IRES-CD34 would provide a rapid (2~3 days for transient transfected cells and 10 ~ 15 days for stable transfected cells) and efficient method for the selection of transfected cells.]]> QU Xiao-Xia,QIN Li-Peng,YUE Wen,GAO Yan-Hong,LI Yan-Hua,YUAN Hong-Feng,WANG Yun-Fang,LIU Da-Qing,YAN Fang,SHI Shuang-Shuang and PEI Xue-Tao 210true TAO Rong,NING Gang-Min,YANG Yong and ZHENG Xiao-Xiang 209true ZHOU Yan-Hong,ZENG Zhao-Yang,XIONG Wei,LUO Xiao-Min,LI Xiao-Ling,FAN Song-Qing,FAN Song-Qing,LIU Hua-Ying,LI Zheng,YANG Yi-Xin,WU Ming-Hua,TANG Ke,CAO Li,SHEN Shou-Rong and LI Gui-Yuan 208true WANG Jun-Ping,ZHANG You-Ming and SU Yong-Ping 207true FAN Song-Qing,ZHANG Wen-Ling,XIONG Wei,MA Jian,ZHOU Jie,ZHOU Ming,XIAO Bing-Yi,OUYANG Jue,ZHANG Qiu-Hong,TAN Chen and LI Gui-Yuan 206true HAN Ling,HU Hong-Bo,PENG Hua-Song and ZHANG Xue-Hong 205true 2006/6/14 0:00:00 DU Guang-Ying and ZHU Nai-Shuo 204true LI Zhan-Dong,Lü Hui-Tian,YUE Jia-Chang,FAN Chun-Hua,LI Wen and LUO Zhi-Yong 203true YU Yun-Zhou,SUN Zhi-Wei,LIU Zhi-Gang and YU Wei-Yuan 202true PSA6_HUMAN coding human proteasome subunit alpha 6 was cloned into a yeast-displaying expression vector, pICAS-H, which had been inserted a His.tag marker for expression level detection. As probed with a His.tag monoclonal antibody and a specific monoclonal antibody generated by hybridoma, a recombinant yeast strain, α6-MT8, was selected by flow cytometry and fluorescence microscopy analysis. Combining with enzyme-linked immunosorbent assay (ELISA), ‘yeast-ELISA’ detection was established by basing on Saccharomyces cerevisiae cell surface engineering and applied to examined monoclonal antibody and its valance. The yeast-displaying recombinant antigen α6 with highly specific affinity was expressed efficiently after 48 h cultivation. The ‘yeast-ELISA’ was demonstrated primarily to detect and screen monoclonal antibody successfully.]]> 2007/5/29 0:00:00 TANG Yu-Qian,YE Mao,lIN Ying,HAN Shuang-Yan,ZHENG Hong,WANG Xiao-Ning and LIANG Shi-Zhong 201true 2007/9/17 0:00:00 WANG Hong-tao,ZHANG Shao-ling and LIU Wang-Yi 200true g. The resulting mixture of microcells, whole cells, karyoplasts and cytoplast fragments was filtered through 8 μm and 5 μm size membrane pores sequentially to obtain pure preparation of microcells. Microcells were then characterized by Giemsa staining and microcell PCR was first applied for examination of the quality of microcell preparation. The result showed that microcells containing our interest chromosomes-human chromosome 12 were equally distributed in the preparation, the preparation was suitable for use in generation of transchromosomic animals.]]> 2007/5/22 0:00:00 HE Zu-Yong,SUN Xiu-Zhu,ZHAO Yong-Hui and LI Ning 199true 2007/5/28 0:00:00 JIANG Xiao-Yu,ZENG Nan,HE Yong-Hong and MA Hui 198true 2007/4/16 0:00:00 Zhang Yan-Jun,Zhu Zhi-Feng,Lu Rong,Xu Qiong,Shi Lin-Xi,Jian Xu,Liu Jun-Yan and Yao Zhi 197true gfp gene was excised from gene-donor vector pTLG and transferred directly to gene-receiving vector pET-LoxP mediated by Cre recombinase, completing the construction of pET-gfp very quickly and simply. Afterwards, gfp gene was expressed in Escherichia coli BL21(DE3) and generated visible green fluorescence colonies. It extremely simplified traditional courses of vector construction to only a reaction mediated by recombinase. Recombination ratios affected by circular gene-donor vector pTLG and linear pTLG were quantified and compared with. A good reference was provided for gene easy cloning or sub-cloning mediated by Cre recombinase.]]> 2007/5/29 0:00:00 WANG Wen-Qi,GAI Ying,LU Hai,LI Yi and JIANG Xiang-Ning 196true in situ hybridization) is a powerful tool for molecular cytogenetics such as chromosome identification and physical mapping in plant. Due to the large proportion of repetitive sequence occurring in some plant species，especially the polyploidy species, the application of BAC-FISH was hindered severely. Molecular markers from a high-density genetic map of tetraploid cotton were used to screen BAC libraries. Protocols of BAC-FISH in cotton mitotic and meiotic cells were introduced by some modifications such as root tip preparation, slide denaturation and post-hybridization washing according to previous protocols. The dual-color, dual-probe and repeated FISH were also introduced by applying them to physical mapping a random BAC clone on the corresponding chromosome.]]> 2007/5/16 0:00:00 WANG Kai,ZHANG Yan-Jie,GUAN Bing,GUO Wang-Zhen and ZHANG Tian-Zhen 195true in situ PCR and interrogated by hybridization with wild and mutant tagged probes and a pair of dual-color (Cy3, Cy5) universal detectors to determine SNP, and then genotype of each sample can be simultaneously identified by scanning the microarray printed with the denatured detectors on an unmodified clean glass slide. Morever, a pair of given dual-color universal detectors can be applied to any SNP loci by hybridization with allele specific tag probes. In this study, this new method have been applied to the analyze the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism in 96 different samples. The fluorescent ratios (match/mismatch signal) of homozygous samples were over 4.5, whereas heterozygous samples had ratios near to 1.0. The genotyping results were additionally validated by sequencing. By using universal tags and in situ magnetic particle PCR, this simple and cost-effective approach can be widely used in high-throughput SNP genotyping.]]> 2007/4/16 0:00:00 LI Song,LIU Hong-Na,WANG Zhi-Fei,JI Mei-Ju,GUO Ya-Fei,HE Nong-Yue and DAI Ya-Bin 194true Saccharomyces cerevisiae cell surface engineering, combining with enzyme-linked immunosorbent assay (ELISA), a new method has been, which is named as ‘yeast-ELISA’ detection. Here, the recombination yeast cell MT8-1 surface display expressing antigen HPSα6 (Human proteasome subunit alpha 6), and its monoclonal antibody 3D7D12D4 (hybridoma cell line No) was used as study object. The fitful yeast cell concentration of this method is 0.50 A₆₀₀, and it was used to detect monoclonal antibody and its valance (1∶5×10⁵). The specificity and sensitivity of the method was demonstrated by crossing test and interdiction test. The results indicated that ‘yeast-ELISA’ could detect monoclonal antibody directly, and the valance of which is concordance with the result of the proteantigen indirect ELISA. And also this method could be used to antiserum detection, which also has good result. It demonstrates that the method of the ‘yeast-ELISA’ detection was established, which is the supply and application of Saccharomyces cerevisiae cell surface engineering.]]> 2007/5/9 0:00:00 YE Mao,HAN Shuang-Yan,LIN Ying,TANG Yu-Qian and WANG Xiao-Ning 193true 2008/5/29 0:00:00 ZHAO Jin-Yan,YAN Zheng,LIU Zi-Liang and WANG Nan 192true fabD, fabG, fabH, fabA, fabZ, fabB and fabI) of E.coli fatty acid biosynthetic enzymes were cloned by PCR amplifying and appropriate expression vectors were constructed. Under induction assay expression of plasmid encoded proteins was carried out in strain BL21(DE3) and seven enzymes were purified using Ni-NTA agarose resin. In the absence of [2-¹⁴C] malonyl-CoA fatty acid synthetic reaction was reconstituted in vitro by adding seven enzymes and co-factors. And several model reactions were established for identification of special fatty acid biosynthetic enzymes. Meanwhile Clostridium acetobutylicium FabZ function was characterized by this method.]]> 2008/4/8 0:00:00 FENG Sai-Xiang,ZHU Lei,LUO Biao,SUN Yi-Rong and WANG Hai-Hong 191true 2008/6/12 0:00:00 WAN Xiang-Hui,ZENG Zhao-Fang and YANG Xi-Mei 190true 2008/5/8 0:00:00 MAO Jian-Hua,ZHANG Qun-Ye,HUANG Qiu-Hua,CHEN Zhu,CHEN Quan and CHEN Sai-Juan 189true 2007/12/19 0:00:00 CHUN Jun,ZHENG Yan-Feng,WANG Sheng-Hua and CHEN Fang 188true 2007/12/19 0:00:00 XIONG Jun,FAN Feng and QU An-Lian 187true # of PGⅠ and 8101^# of PGⅡ, were co-coated in 96 microtitration wells. The counterpart tracer monoclonal antibodies, 8016^# of PGⅠ and 8102^# of PGⅡ, were labeled with Eu³⁺ and sm³⁺-chelates, respectively. The samples were assayed by one-step sandwich protocol with the time-resolved fluorometry. The measurement ranges of PGⅠ were 0.2～300.0 μg/L with the within-run and between-run precision was 5.2% and 8.1%, and that of PGⅡ were 0.05～55.0 μg/L with the within-run and between-run precision was 7.1% and 11.7%, respectively. The average recovery rates of PGⅠ and PGⅡ were 96.9% and 103.7%, respectively. The results obtained by the dual-label assay agreed well with those by enzyme-linked immunosorbent assays of PGⅠ and PGⅡ, whose correlation ratio were 0.9426 of PGⅠ and 0.9396 of PGⅡ, respectively. The means of 300 healthy volunteers were (157.3 ±51.0) μg/L for serum PGⅠ,(10.6 ± 5.9) μg/L for serum PGⅡ, and (14.8 ± 4.3) for the PGⅠ/PGⅡ ratio. The normal ranges of serum PGⅠ levels for healthy volunteers were 55.3～259.3 μg/L, those of serum PGⅡ levels were less than 23 μg/L, the PGⅠ/PGⅡ ratio was more than 6. The proposed dual-label TRFIA for simultaneous detection of PGⅠ and PGⅡ is a simple, sensitive, and rapid method. It could provide serology high-screening of the samples for gastric diseases and would allow investigations into the possible diagnostic value of analysis in various clinical condition.]]> 2007/10/15 0:00:00 ZHANG Jue,HUANG Biao,ZHU Lan,ZHANG Yi,LIU Hai-Yan,MA Zhi-Hong and GUO Li-Ning 186true 4), and the monoclonal antibody has no cross-reaction to other hepatitis virus. The method of AC-ELISA which was established with monoclonal antibody and polyclonal antibody showed high analysing susceptibility for HBV mutant samples.]]> 2007/11/8 0:00:00 WANG Jun,WANG Ji and WANG Li 185true 2008/5/21 0:00:00 LI Jiang-Wei,RAN Yu-Liang,LI Guo-Hui,HU Hai,LIU Jun,LV Fang,SU You-Hong,SUN Li-Xin and YANG Zhi-Hua 184true 2008/5/13 0:00:00 Huang Mo-Li,SUN Dao-Chun,LOU Ya-Xin,YIN Yan-Bin,LI Chuan-Yun,ZHANG Yong,GAO Ge,WANG Sheng-Qi,BO Xiao-Chen,WEI Li-Ping and LI Song-Gang 183true 2008/6/3 0:00:00 HU Jun,XING Da,YANG Di-Wu,XIANG Liang-Zhong and YANG Si-Hua 182true 2008/6/20 0:00:00 HE Wen-Lei,YANG Wen-Jie,LI Yuan-Yuan and XU Shun-Qing 181true 4Ac/methanol) precipitation method, were compared. Four ecotypes of reed plants (Phragmites communis Trin.) from the desert region of north-western China were used as experimental materials: (1) swamp reed (SR) which grows in water about 1 m deep; (2) dune reed (DR) which grows on 5～10 m high sand dunes; (3) heavy salt meadow reed (HSMR) which grows on low-lying salt flats; and (4) light salt meadow reed (LSMR) which grows in the transition area between DR and HSMR growing areas. The optimized phenol-NH4Ac/methanol precipitation method consisted of extracting leaf proteins of different ecotypes of reed with water-saturated phenol and then precipitating with a 5-fold volume of 0.1 mol/L NH4Ac in methanol, followed by dissolving in the lysis buffer. The optimized protein lysis buffer consisted of 7 mol/L urea, 2 mol/L thiourea, 4% CHAPS, 2% Ampholine(pH 3.5～10∶pH 5～8 = 1∶4) and 65 mmol/L DTT. The prepared protein sample (80 μg) was then separated by 2-DE gel and detected by silver staining method. This improved 2-DE system resulted in a 2-D protein profile of higher resolution and higher protein yields as analyzed by PDQuest software. Good results were also obtained when this 2-DE system was used in 2-D analysis of proteins from other plant materials, such as rice leaves, indicating that it is a suitable 2-DE system for analyzing leaf proteins of different plant species.]]> 2008/4/8 0:00:00 LIN Wen-Fang,CHEN Lin-Jiao,PENG Hao and ZHU Xue-Yi 180true 2009/4/24 0:00:00 ZHAO Ying-Jie and WANG Zhi 179true PDS, which was related about synthesis of lycopene, was used as marker gene to establish the model of screening. Among one hundred mixed agrobateria, PDS was successfully screened in the first stage of model establishment.]]> 2009/3/11 0:00:00 WANG Xiao-Guang,MA Yuan-Zheng,WANG Xiao-Hui,LI Ling,LUO Yun-Bo and ZHU Ben-Zhong 178true 2009/1/10 0:00:00 XU Huan-Yu,MA Qing-Wen,REN Zhao-Rui,GONG Zhi-Juan,HUANG Shu-Zhen,ZENG Fan-Yi and ZENG Yi-Tao 177true eag gene in B. anthracis AP422. To construct the recombinant vector, homologous regions and Spc^r cassette with two loxP sites were amplified from the corresponding templates. The produced shuttle vector was then transformed into B. anthracis AP422. Under the pressure of temperature and antibiotic, homologous recombination occurred between the vector and genome of the host bacterium and the recombinants were selected by agar media with spectinomycin (Spc) and X-gal. To remove the Spc^r cassette, a plasmid with Cre recombinase was introduced into the recombinant to delete the relevant DNA fragment, resulting in a single loxP site within the targeted genomic segment. The markerless mutant strains were detected by genome PCR, RT-PCR, total proteins SDS-PAGE analysis and Western blot. The results showed that the eag gene was successfully deleted.]]> 2009/3/26 0:00:00 WANG Yan-Chun,JIANG Na,ZHAN De-Wen,QIU Yan,YUAN Sheng-Ling,TAO Hao-Xia,WANG Ling-Chun,ZHANG Zhao-Shan and LIU Chun-Jie 176true 2009/1/19 0:00:00 ZHAO Yan,CHEN Li-Na,ZHANG Liang-Cai,WANG Qian,SHANG Yu-Kui,WANG Hong and LI Wan 175true in vitro, by a soft lithography technique. Three different substrates, including Laminin(LN), poly·L-lysine(PLL) and PEI characterized with strong positive surface charges were micro-patterned using soft lithography techniques. Striatal neurons from postnatal rats were cultured in vitro. The condition of cell adhesion, living and the neurite growth of the cultrued neurons on different substrates were observed, and the differences of neural network patterns fabricated on the three substrates were evaluated. The quantity of neuronal growth on the surface of PEI and PLL is apparently larger than that on LN. Moreover, the coated pattern of neurons on the PEI is more integrated than that on the PLL and LN. The PEI characterized with strong positive surface charges is capable of well fabricating more continuous and integrated neural patterns, which is an ideal interfacial surface to realize the artificial neural network in vitro．]]> 2008/12/22 0:00:00 GAO Kan,LIU Bing-Fang and XU Qun-Yuan 174true 2008/11/3 0:00:00 WANG Jing and FENG Zhou-Yan 173true 2009/2/10 0:00:00 YANG Qian,XIONG Qiang,JIANG Cheng-Tao,LI Cai-Xia,SUN Ai-Mei,KEITH MITCHELSON,XING Wan-Li,YE Jian and CHENG Jing 172true S/N=3) is 6×10^-3 U/L. The coefficients of variation of peak time and areas were 5.32% and 3.17%. The method is easily operated. To application microfluidic chips with the method, the sensitive of detectable enzyme will be much more improved．The method for trace enzymes has potential for clinical application.]]> 2008/11/18 0:00:00 CONG Hui,WANG Hui-Min,JU Shao-Qing,JIN Qing-Hui,JIA Chun-Ping and SONG Hong-Wei 171true 2008/7/14 0:00:00 JIAN Qiang,YU Han-Jie,CHEN Chao and LI Zheng 170true 2008/11/3 0:00:00 CHEN Xiang,BU Dong-Bo,ZHANG Fa and GAO Wen 169true 2009/5/13 0:00:00 SUN Han-Chang,LI Dong,WANG Jian,LIU Zhong-Yang,Zhu Yun-Ping,XIE Hong-Wei and HE Fu-Chu 168true 2N=-0.935 4ΔCt+3.411 6 (R²=0.997 4, P < 0.001), and copy number were 30.85±1.77, 18.87±1.34, respectively, in two transgenic pigs; transgene integration site was successfully cloned by TAIL-PCR, and 25 bands were obtained. Three integration sites, named TgInS1 (1 440 bp), TgInS2(1 263 bp) and TgInS3 (1 861 bp), were detected by BLAST; Junction PCR combining with integration site and transgene specific primers was performed and specific bands confirmed the integration site; Junction PCR combining with 5′ and 3′ integration site and transgene specific primers was performed to analyze integration site zygosity. Bands amplified by 5′ and 3′ integration site specific primers just as WT control were obtained to determine the heterozygosity of integration site. Absolute quantitative PCR, and TAIL-PCR were established to check transgene copy number and integration site, and it has laid the foundation to study the inheritance and expression stability of transgene in transgenic animals.]]> 2009/7/15 0:00:00 KONG Qing-Ran,WU Mei-Ling,ZHU Jiang,BOU Gerelchimeg,HUAN Yan-Jun,YIN Zhi,MU Yan-Shuang and LIU Zhong-Hua 167true T_m≤58℃) as flanking primers. After first round PCR, 12.5 μl first PCR production was directly added into 50 μl second PCR system as template and megaprimer, and 10 rounds of asymmetrical PCR at high temperature of annealing (68℃) was to add in initiation of second PCR. This additional step greatly has increased the efficiency of mutagenesis via 600 bp or 800 bp long megaprimer. The results demonstrated that this method can achieve high fidelity, 97%～98% efficiency, high yield.]]> 2009/6/12 0:00:00 XIE Zhen-Hua and SHI Xiao-Jun 166true 2009/6/30 0:00:00 LIU Ran-Ran,YUAN Jing,ZHAO Xing-Bo and LI Ning 165true 2009/5/25 0:00:00 WANG Nian,KANG Xiao-Nan,LIU Yin-Kun,GUO Kun,CUI Jie-Feng,SUN Rui-Xia,CHEN Jie,ZHAO Yan and CHEN Pei 164true Bombyx mori nucleopolyhedrovirus (BmNPV), BmN cells were transfected with transgenic vector pigA3-LEF-Neo containing lef-1 dsRNA expression cassette, to produce stable transformation cell line screened with G418(750～800 mg/L). Virus infection test showed that (1) the infection ratio of the stable transformation cells was lower than that of normal cells by 53%, (2) the quantity of polyhedron from transformation cells were 2/3 of that of normal cells and (3) the number of liberation virus from cell culture′s supernatant decreased more than 90%, suggesting that the virus′ proliferation in the transformation cells was depressed significantly. The result underlying the transcriptional level of the lef-1 gene in the transformation cells was only 2/5～3/5 of that in the normal cells suggested that the transcribed lef-1 dsRNA in transformation cells inhibited the expression of the lef-1 gene. Inverse PCR was used to locate the site of exogenous DNA fragment insertion in genome, of which the result showed that in the transformation cells, exogenous DNA could be inserted into the cell genome randomly or at TTAA target sequence specifically for piggyBac element transposition.]]> 2009/9/3 0:00:00 LU Yin-Song,XUE Ren-Yu,CAO Guang-Li,ZHANG Peng-Jie,LIU Bo and GONG Cheng-Liang 163true 7 L/mol) and are able to cross-react to Chlorpyifos, Parathion, Profenofos, Omethoate, Dichlofenthion, Diazinon, Bromophos, Phoxim. This immunoassay is therefore capable of detecting 8 different organophosphorus pesticides. It is concluded that this assay is a qualified screening tool for quantitative or semi-quantitative detection of the 8 organophosphorous pesticides.]]> 2010/6/10 0:00:00 ZHANG Li-Jie and PAN Jia-Rong 162true Brassica juncea L., which is typical characterized with yellow leaves and no other different traits from the wild type except leaves color. In order to efficiently analyze the differential expression proteins between the mutant L638-y and its wild type L638-g, two protein extraction methods for proteomic analysis, TCA/acetone extraction method and an improved polyethylene glycol ( PEG) fractionation method, were compared. Total proteins were extracted from leaves of the mutant L638-y and its wild type L638-g at five leaves period with the two protocols, then the samples were analyzed by 2-DE, pH of IPG strip and concentration of SDS-PAGE being optimized. The results showed that when using 17 cm linear IPG strips pH ranged from 4 to 7, 11% SDS-PAGE, loading 180 μg/350 μl, proteins were better separated. Much more protein spots had been observed in 2-DE maps of the protein samples prepared by the PEG fractionation than TCA/acetone precipitation. In 2-DE profiles of the protein sample from mutant L638-y prepared by the PEG fractionation, as much as 1 235±6 protein spots were identified, 330 more spots than those by TCA/acetone precipitation method. By using the PEG fractionation, 190 differential protein spots were identified between the 2-DE maps of the mutant L638-y and wild type L638-g, 100 more spots than those by TCA/acetone precipitation. Thus, the improved PEG fractionation is more efficient and simple for proteomic analysis of chlorophyll-deficient mutants in Brassica Juncea L.]]> 2010/5/20 0:00:00 ZHANG Rui,LIU Hai-Heng,ZHAO Hui-Xian and HU Sheng-Wu 161true 2010/5/20 0:00:00 WANG Hong,QU Xiao-Li,ZHAO Yan,ZHANG Jing and CHEN Li-Na 160true 2010/6/22 0:00:00 MENG Yang,HE Zhen-Ni,YIN Jian,ZHANG Yu and ZHANG Tian-Hao 159true 2010/1/19 0:00:00 LOU Yan-Kun,LUO Juan,DAI Rong and LI Ning 158true 5 by indirect enzyme-linked immunoassay. The indirect competitive ELISA showed that the detection limit of CIT was 10 μg/L, with a good linearity ranging 10～250 μg/L, and IC₅₀ was 100 μg/L. Immunogenicity of antigens prepared by different methods was analyzed. The result showed that the epitope was the carboxyl group at C₇. This work would be helpful for establishing the technology and developing the kit to determine CIT-contaminated samples by ELISA.]]> 2009/12/22 0:00:00 WANG Yuan-Yuan,LI Yong-Ning and GUO Yang-Hao 157true 2009/12/23 0:00:00 WANG Wen,QU Wu-Bin,SHEN Zhi-Yong,REN Chong-Hong,LIU Hu-Qi and ZHANG Cheng-Gang 156true 3 and HDL₂ could be separated in 4 min. HDL subclasses could be separated with high efficiency and good reproducibility. The operation was easy and cost little. This method could meet the demand of the clinical examination of HDL subclasses, with good clinical value.]]> 2009/12/15 0:00:00 ZHENG Hui-Fei,CONG Hui,WANG Hui-Min,JIN Qing-Hui and ZHAO Jian-Long 155true In vitro matured pig oocytes were either activated parthenogenetically or microinjected with a somatic cell, followed by electro-fusion. At 24 h post activation(hpa), PA and SCNT embryos were assessed visually, and cleaved embryos were moved into new culture wells. This process was repeated at 36 hpa or 48 hpa. Embryos in different groups were allowed to develop for 6 days in culture. The relationship between embryo developmental competence and the first zygotic cleavage at different timing (early-cleaving, 20～24 h; mid-cleaving, 25～36 h; late-cleaving, 37～48 h and unselected controls, 20～48 h) was evaluated by the proportions of cleaved embryos developed to blastocysts and expanded blastocysts (EB), and blastocyst total cell number. For PA embryos, the proportion of early-cleaving embryos that developed to blastocysts was significantly higher than that of mid-cleaving, late-cleaving and controls (P < 0.05; 54.0% vs. 19.6%, 5.4% and 18.7%, respectively); a similar pattern was noted for the formation of EB. For SCNT embryos, the proportion of early-cleaving embryos developing to blastocysts was not significantly higher than that of mid-cleaving embryos (32.2% vs. 23.5%), but the late-cleaving embryos had poor developmental competence to blastocysts (6.3%). Early-cleaving SCNT embryos showed a significant higher competence developing to expanded blastocysts than the mid-, late-cleaving and unselected control embryos (P < 0.05; 18.9% vs. 5.9%, 3.1%, 7.4%, respectively). Total cell number in the blastocysts declined across the three cleavage-timed groups. Developmental potential of SCNT cloned embryos was assessed in vivo by transferring early-cleaving (< 24 h) and unselected (time of cleavage up to 48 h not determined) embryos into recipient gilts. Litter size and cloning efficiency (piglets born/transferred embryos) in recipients of early-cleaving embryos were significantly higher than those in recipients of unselected embryos (4.7 vs. 2.1 piglets; 3.9% vs. 0.9%). The data demonstrate that the developmental potential of early-cleaving SCNT embryos is higher than that of later-cleaving embryos, thus suggesting that timing of the first zygotic cleavage can be utilized as a useful parameter for indicating developmental potential of porcine cloned embryos.]]> 2010/8/31 0:00:00 LUO Xue-Ming,XIAO Wei,FENG Chong,LONG Chuan,YAN Jun,XUE Zhen-Hua,YUN Peng and PAN Deng-Ke 154true 8 L/mol and the IC₅₀ value was 0.3 μg/L. Its linear range of the assay was between 0.05 μg/L and 1.0 μg/L. The cross-reactivity rates were less than 0.1% of other toxins such as ochratoxin A, aflatoxin B1, deoxynivalenol, zearalenone and were less than 0.01% of rubropunctatine and rubropunctamine. This work would be helpful for establishing the technology and developing the kit to determine CIT-contaminated samples by ELISA.]]> 2010/6/23 0:00:00 LI Yong-Ning,WANG Yuan-Yuna,ZHENG Yun-Quan and GUO Yang-Hao 153true 2010/5/27 0:00:00 ZHANG Yong-Deng,CHEN Liang-Yi and XU Tao 152true 2011/5/24 0:00:00 HUANG Zhi-Hua,LI Ming-Hong,MA Yuan-Ye and ZHOU Chang-Le 151true 2011/4/28 0:00:00 XU Min-Juan,ZHU Xiao-Mei,LIN Pao-Hung and AO Ping 150true d_y(selected evolutionary distance) between species was obtained. Selected evolutionary distance d_y was calculated in 4 nucleotide substitution models, and indicated the relationship among p-distance, d-distance and Г distance d_G. According to the characteristics of dynamic equations, selection model can be transformed into a linear regression problem. Then both of the parameter b and the average substitution ratio of nucleotide each year r were obtained by the Least Square Method. Take the mitochondrial DNA sequences of 16 species for example to illustrate the new evolution distance, and then evolution trees are constructed in order to compare different evolution distance. The results indicate that the new distance d_y is an efficient evolution distance to analyze DNA sequence.]]> 2011/4/2 0:00:00 LIANG Li-Ping,XIE Xiao-Li,CHENG Jian,WANG Zhen-Feng,GUO Man-Cai and YUAN Zhi-Fa 149true et al), and the difference of the transcriptional level of RAC2, RhoBTB3, SPA-1 and Rap1GAP relative to GAPDH were analyzed using wilcoxon non-parametric test and SNK method among different groups. The results were confirmed by RQ-PCR. The bead-based flow-cytometric array had an excellent sensitivity and a wide linear range, could get a positive signal for PCR product from 0.002 5 to 0.1 μmol, the fine specificity was proved by no cross-hybridization signals presented among different bead set, and the reproducibility were also good enough(P < 0.001). The expression profiling of RAC2, RhoBTB3, SPA-1, Rap1GAP and GAPDH detected by this liquid bead-based flow-cytometric array were obtained, and there existed significant difference among 5 groups ( MDS-RA, -RAEB, -RAEBt, AML, and control group )for the relative expression to GAPDH of RAC2, RhoBTB3, SPA-1 and Rap1GAP (P < 0.0001, P = 0.049 1, P = 0.020 6 and P = 0.004 6 respectively). These results were validated by RQ-PCR, and the data obtained by each method had close linear correlation, the Pearson correlation coefficient was 0.930, 0.946, 0.945 and 0.921 for RAC2, RhoBTB3, SPA-1 and Rap1GAP respectively(P < 0.001 for all four). A bead-based flow-cytometric multiplex assay for rapid assessment of gene expression profiling has been built successfully, and it was validated by RQ-PCR.]]> 2011/1/28 0:00:00 SHAO Xue-Jun,CHEN Zi-Xing,MIAO Mei-Hua,CEN Jian-Nong and SHEN Hong-Jie 148true 3+ (anti-Insulin) and Sm³⁺ (anti-C-peptide) chelates, respectively. The double antibody sandwich in one step method was used to develop the TRFIA for simultaneously detection of the C-peptide and insulin in human serum. These results showed that sensitivity of C peptide analysis was up to 0.2 μg/L, linear range is 0.5～22 μg/L, the recovery percent is 99.6%, The intra- and inter-assay coefficient of variation were 4.6%～6.0% and 5.1%～7.6%, respectively; sensitivity of insulin analysis was up to 0.8 mU/L, linear range is 3.6～180 mU/L, the recovery percent is 99.4%, the intra- and inter-assay coefficient of variation were 3.7%～6.0% and 5.1%～8.0%, respectively. Moreover, 200 samples were tested by the self-made and commercially available C-peptide and insulin kit (PerkinElmer) kits at the same time. The correlation coefficient was 0.98 and 0.99, respectively. In conclusion, the self-made dual-labeling time-resolved fluoroimmunoassay for simultaneously detection of C-peptide and insulin might be a simple, sensitive and rapid method for rapid diagnosis for the diabetes caused by the lack of insulin secretion, it would also provide an alternative route for serology high-screening of the samples for C-peptide and insulin in clinical application.]]> 2011/3/23 0:00:00 MA Qiang,LI Lai-Qing,HE An,LIN Guan-Feng,ZOU Li-Ping,LI Ming and WU Ying-Song 147true 2011/3/8 0:00:00 QIN Xia,ZHANG Shi-Meng,XU Qin-Zhi,YE Qi-Nong and ZHOU Ping-Kun 146true 2011/1/13 0:00:00 ZUO Lie-Lian,LU Jian-Hong,YU Hai-Bo,YU Zheng-Yuan,YAN Qi-Jia,HE Wei,TANG Ke and LI Gui-Yuan 145true 5 to 4.3×10⁵ copies per cell. Interestingly, the fold-change of U6 ncRNA and 5S rRNA were found to be 1.5- and 4.8-fold (based on DNA normalization), and 5.8- and 3.8-fold (based on RNA normalization), indicating significant expression variations of these two house-keeping genes. The study provides an novel approach to reliably normalize miRNA expression in quantitative PCR.]]> 2010/12/27 0:00:00 JIN You-Fang,XU Gen-Ming,LI Yan,MENG Li,JIANG Yong-Hou,GUO Jiang-Feng and DING Xian-Feng 144true in vivo recording, in the study of learning and memory. To overcome the disadvantages and inconvenience in current hippocampal field potential recording and raise in vivo experimental efficiency, stimulation/recording/drug delivery system for in vivo hippocampal field potential recording was developed and applied. Anesthetized SD rats were fixed in a stereotaxic device and a homemade stimulation/recording/drug delivery system was used to record field excitatory postsynaptic potential (fEPSP) in hippocampal CA1 area. The results showed that fEPSPs were easily evoked by nearly every test stimulus and maintained steadily for a long time by using the stimulation/recording/drug delivery system; high frequency stimulation (HFS) successfully induced early-phase LTP (E-LTP) and 1ate-phase LTP (L-LTP); the baseline fEPSPs and LTP were promptly and effectively suppressed by intrahippocampal injection (IH) of AMPA receptor antagonist CNQX (100 μmol/L, 1 μl) and NMDA receptor antagonist AP-5 (100 μmol/L, 1 μl) , respectively, with a shorter latency and a reduced dose compared with intracerebraventricular injection (ICV); the induction and recording of paired pulse facilitation (PPF) were also considerably easy and stable using the combination device. In short, the simplicity, reliability and high efficiency of stimulation/recording/drug delivery combination system in recording in vivo rat hippocampal CA1 area field potential make it more practical in the research of synaptic plasticity, and this technique established an important foundation for the study of higher cognitive brain function.]]> 2010/12/27 0:00:00 WANG Xiao-Hui,YANG Wei,YUAN Li,LI Shao-Feng,YANG Dong,PAN Yan-Fang and QI Jin-Shun 143true DpnⅠ treatment, agarose gel purification, self-ligation and transformation into DH5α. Three colonies were randomly selected for DNA sequencing. The expression of both the PIAS3 wide type and the point mutants( PIAS3 K110R and K411,412R) was analyzed by transfection of these plasmids into 293T cells. The result showed that the PIAS3 K110R and K411,412R point mutants were successfully constructed and expressed in mammalian cells, which suggested that the novel inverse PCR stratagy can be applied to construct the point mutants of a target gene efficiently and conveniently.]]> 2010/11/18 0:00:00 CHENG Long,HAN Bai-Yu,HOU Sha,HAN Yong-Jian,XU Xiao-Jie,JIANG Kai,LI Fa-Ceng,YANG Zhi-Hong,ZHANG Hao,DOU Jing-Tao,LV Zhao-Hui,ZHANG Hao and YE Qi-Nong 142true XmnⅠ restriction site was converted into a HindⅢ site in the Gateway entry vector pENTR-2B to generate pENTR*-2B and a Gateway entry vetcor designated as pENTR*-PrbcS-*T-GFP was constructed by subcloning the tomato Rubisco small subunit 3C promoter (PrbcS) and its transit peptide sequence (*T) as well as a GFP (green fluorescent protein) reporter gene into pENTR*-2B. These results demonstrated that the pENTR*-PrbcS-*T-GFP could be used to generate the plant expression vector via Gateway technology for targeting the expressed GFP into the chloroplasts of transgenic plant leaves. Similar results were also obtained for GUS (β-glucuronidase) reporter gene when it was used to replace the GFP gene in pENTR*-PrbcS-*T-GFP. These results indicated that pENTR*-PrbcS-*T-GFP can be generally applied to generate an entry vector for a target gene by replacement of the GFP with the target gene and the plant expression vector that serves to localize the expressed target protein in chloroplasts can be achieved rapidly via Gateway technology.]]> 2010/11/18 0:00:00 MA Li,SONG Zhong-Bang,HU Qing-Quan,ZHAO Yue,NIAN Hong-Juan,YU Yong-Xiong,LI Kun-Zhi and CHEN Li-Mei 141true 2010/8/24 0:00:00 WANG Ying,SUN Da-Quan and LIU Ding-Gan 140true C and steepness S. For each transcription factor, the parameters of model can be fixed by analysis of relativity between transcription factor binding scores in promoter regions and gene expression levels. Here three relativity values should be computed while different formula is used to calculate transcription factor binding score. Relativity value A is obtained when transcription factor binding scores are calculated without considering methylation effect. Relativity value B is analyzed from transcription factor binding scores considering methylation effect with the proposed model. On the contrary, normal sigmoid function is used to depict effect of DNA methylation and relativity value C is just calculated with transcription factor binding scores considering methylation effect using such model. For a transcription factor, if relativity value B is found obviously larger than relativity value A and relativity value C is always less than relativity value A, the transcription factor can be figured out to be apparently affected by DNA methylation and the model with optimal fixed parameters can be used to depict the methylation effect. In neuroblastoma cell, with the proposed model, 10 transcriptional factors were found to be apparently affected by methylation of promoter regions which proves the effectiveness of the model. Based on the proposed model, TF binding status in genome promoter region can be presumed to further investigate how a gene is regulated by a specific group of TFs organized in a particular pattern, which should be helpful in building of gene regulation network. Moreover, if it is exactly obtained how methylation exerts quite different effect on the same TF between normal and cancer cells, the proposed method also can be used as a way to search mutant TFs which would be responsible for the cancer. But, as so many factors including DNA methylation are involved in gene transcription process and to investigate regulation mechanism of gene transcription is still a hard job.]]> 2010/11/23 0:00:00 FENG Wei-Xing,WANG Ke-Jun,HE Bo and LI Xia 139true n=5) were measured through UV-HPLC. Homogenizing brain tissues with 10% trichloroacetic acid (pH=1.0) not only avoided the disturbance from contaminated protein and other compounds, but also eliminated the step extraction of FA-DNPH derivative (2, 4-dinitrophenylhydrazone) and improve the methodological sensitivity (P < 0.05). The porcine brain formaldehyde was 75.5～83.4 μmol/kg fresh brain tissues measured by this improved method. Recoveries of spiked formaldehyde at low and high level were 95.96%～102.04% with relative standard deviations less than 10%. This suggests that the modified 2, 4-DNPH method is effective enough to measure the endogenous formaldehyde in brain tissues.]]> 2011/11/29 0:00:00 SU Tao,WEI Yan and HE Rong-Qiao 138true 2011/11/14 0:00:00 ZHENG Ming,HUANG Yan-Xin,SHEN Wei,ZHONG Yi,WU Jia-Nan,LIU Gui-Xia and ZHOU You 137true in vitro protein binding assay. This recombinant protein binding assay can be used to verify the inhibitor candidates selected from the fluorescence screening model directly blocking the interaction of MyD88 TIR or not. The fluorescence screening model plus the in vitro verifying assay can be broadly used with commercially available compounds banks or lab-made natural products to find effective anti-inflammation inhibitors for therapeutic treatment of MyD88-pathway related chronic inflammation or autoimmune disorders.]]> 2011/11/23 0:00:00 ZHAO Yan,XUE Yan,JIANG Xue,ZENG Xian-Lu and BA Xue-Qing 136true K_a. We replaced the green fluorescent protein (GFP) and photoactivatable protein mEOS2 chromophore Tyr (Tyr66 in GFP) by 3-Cl-Tyr, lowering the chromophore pK_a to 4.2 and 4.7, respectively. These mutant fluorescent proteins with lower pK_a may be advantageous for labeling proteins in acidic organelles such as lysosome and phagosome.]]> 2011/10/24 0:00:00 ZHANG Wei,WANG Yue-Qi and WANG Jiang-Yun 135true Sorangium have been an important source of new drugs. The proteome analysis is an effective method to study the regulation of metabolism. However, the genus Sorangium contains a large amount of exopolysaccharides or slime that interferes with protein solubility, resolution, and repeatability in proteome analysis. To perform high-throughput screening of the specific proteins expressed by Sorangium cellulosum So0157-2, we optimized the two-dimensional electrophoresis (2-DE) protocol. Firstly, the proteins have better solubility in lysis buffer. The pH 3～10 NL strip is appropriate for the first-dimensional isoelectric focusing, improving the resolution of protein spots. 1 mg of protein was used in the isoelectric focusing, improving the expression of low-accumulation proteins. 15% SDS-PAGE improved the resolution and repeatability for separation of these proteins. Based on the optimal 2-DE protocol, the protein patterns of S. cellulosum So0157-2 cultured in M26 medium for three days were acquired, and 552 protein spots were detected. Further, the expressed proteins (85.9%) were identified by MALDI-TOF-MS. The identified proteins included components of cell structure and function, and cell metabolic enzymes. Worthy to be mentioned, 8 proteins were related to the transformation and metabolism of carbohydrate, which were contributed to the in-depth study of epothiloneoside A. This optimal protocol laid the foundation for the further construction of proteome expression database of S. cellulosum So0157-2 in various industrial culture conditions.]]> 2011/7/26 0:00:00 ZHANG Peng-Yi,LI Yue-Zhong,WU Zhi-Hong,LIU Hong,XU Pei-Pei and XIONG Juan 134true 2012/3/19 0:00:00 YANG Song,TENG Yan and XU Ping-Yong 133true in vitro) were treated with 100 μmol/L glutamate to generate moderate excitotoxicity. The model was validated by examining intracellular calcium dynamics and c-fos expression. Results show that this method is stable and reproducible and may be helpful for researchers using the excitotoxicity model to study neuropathological processes.]]> 2013/8/21 0:00:00 WANG Tie-Peng,ZHANG Ting and CHEN Chang 132true DpnⅠ treatment, agarose gel purification, dam methyltransferase treatment, self-ligation and purification with PCR extraction kit. Afterwards, the second run of inverse PCR was performed and the PCR products were treated as above protocol. The second processed PCR products were then used as the template for the third run of inverse PCR. The exact run times of inverse PCR are according to the number of mutation sites that you wanted. The PCR products of the last run were treated with DpnⅠ, purified with agarose gel extract kit, self-ligated and were transformed into DH5α. Ten colonies were randomly picked up for plasmids extraction and DNA sequencing. The expression of both the SRrp53 wild type and five-site mutants was analyzed by transfection of these plasmids into 293T cells. The DNA sequencing results showed that 9 of 10 extracted plasmids gained the correct mutations. And after these 9 correct plasmids were transfected into 293T cells, all of the mutants were expressed with the right molecular mass. In a word, our novel strategy can be applied to generate multiple-site mutants of a target gene efficiently and conveniently. The method has laid a good foundation for further exploration of this protein's function.]]> 2013/7/24 0:00:00 CHEN Li-Han,LI Wei-Ni,ZHANG Hao,CHENG Long and YE Qi-Nong 131true 2013/5/22 0:00:00 DUAN De-Min,HUI Li-Xing,LI Li-Shi,YAN Xi-Yun and LI Jiong 130true i.e. to immobilize an A/U-rich RNA to a solid medium amine M-270 magnetic beads by coupling them in a direct condensation reaction using the soluble carbodiimide reagent EDC, and then to isolate RNA binding proteins from cell lysate by RNA affinity chromatography using the immobilized RNA. The RNA specific binding proteins were then identified by SDS-PAGE, mass spectrometry and Western blotting, such as hnRNPC which bound specifically to the A/U-rich RNA of C/EBPβ 3'UTR. Colocalization in vivo between A/U-rich RNA and the identified protein hnRNPC was shown by fluorescence in situ hybridization using RNA molecular beacon and anti-hnRNPC antibody and confocal microscopy. Our results indicated that the direct immobilization of RNA with EDC is highly efficient, simple and easy.]]> 2013/4/23 0:00:00 SUN Da-Quan,WANG Ying and LIU Ding-Gan 129true 2013/3/26 0:00:00 YU Ying-Xin,LIU Yan-Jun,JIAO De-Long,WEN Li-Yan,XU Jiang-Ping and FU Ning 128true S/N > 3) of AMP, ADP and ATP were 1.9291, 1.8794 and 166.5 nmol/L, and their limit of quantifications (LOQ, S/N > 10) were 1.9632, 1.9672 and 185.6 nmol/L, respectively. The recoveries of the spiked standards varied from 81.8% to 107.8% with relative standard deviations (RSDs) less than 7.55%. The intraday precisions of AMP, ADP and ATP were 6.16%, 5.13% and 7.66%, and their interday precisions were 6.36%, 2.74% and 6.77%, respectively. The method was fast, simple, sensitive and suitable for the quantitative analysis of AMP, ADP and ATP in cell extracts. Analysis of AMP, ADP and ATP in human lung cancer A549 cells treated with different concentration volatile oils of Alpinia officinarum Hance, the results showed that the total level of cellular adenylate energy and ECP were decline with concentration dependence. The levels of ATP/TAN were decreased significantly when the concentration was 500 mg/L but the level of AMP/ATP in A549 cells were increased with concentration dependent. It was suggested that the volatile oils of Alpinia officinarum Hance inhibited cell proliferation by affecting the cellular energy metabolism.]]> 2013/3/22 0:00:00 LI Ning,ZHANG Hai-Tao,LUO Hui,ZHANG Liang-Tao,XIONG Yong and JIA Zhen-Bin 127true Caenorhabditis elegans has been widely used as a perfect model organism to study the relationship between genes and behavior. The pharyngeal microcircuit of the worm controls a complex feeding behavior. In order to study the molecular basis of this feeding behavior, it is necessary to identify subtle differences in feeding activity of the worm. However, most of the phenotype analyzing of feeding behavior is accomplished by human eyes. And it is a tough and poor efficiency job to analyze the fast pumping muscle of the worm. To help improving this problem, an automated system has been developed based on computer vision for the high-throughput analysis of the feeding behavior by virtue of a simple webcam. Our system enables the consistent and subtle analysis of C. elegans pumping recordings and the accuracy of pumping detection is up to 98%. Under this high accuracy, the time cost of the behavior analysis is cut down by 67% versus human manipulation.]]> 2013/2/26 0:00:00 ZHANG Hai-Ning,HUANG Wen-Ming,FU Jia-Jun,XU Xiang-Ping and XU Tao 126true hLY) gene transgenic pigs, the present study was carried out to investigate the effects of different electric activation parameters and chemicals on in vitro development of embryos derived from parthenogenesis (PA) and somatic cell nuclear transfer (SCNT). The results showed that the electric strength could influence the fusion rate and developmental ability of SCNT embryos (P < 0.05), and number of electric pulses had no significant effect on SCNT embryos development (P > 0.05), yet different variation tendency was found in developmental ability between PA and SCNT embryos under same activation parameters. The blastocyst rate of SCNT embryos was improved when treated with CHX CB for 4 h after electric activation (P < 0.05), whereas 6-DMAP did not (P > 0.05). On the contrary, either CHX CB or 6-DMAP treatment after electric pulses could improve the blastocyst rate of PA embryos, indicating that the best activation method for PA was not necessarily the best for SCNT. The best activation protocol of SCNT embryos in our study is two pulses of 100 μs, direct current of 1.6 kV/cm electric strength with 100 μs interval, and followed by CHX CB treatment for 4 h. With the activation protocol, the mammary gland expressed hLY transgenic pigs were generated. It could help for improving piglets survival rate in transgenic breeding.]]> 2013/2/28 10:38:33 WEI Heng-Xi,LI Jun,TONG Jia,MA Yu-Fang,GAO Feng-Lei,LI Qiu-Yan,ZHANG Shou-Quan and LI Ning 125true 2013/12/20 0:00:00 JIA Xiao-Dong,CHEN Xiu-Jie,WU Xin,XU Jian-Kai,TAN Fu-Jian,LIU Xiang-Qiong,LIU Lei and YANG Rui-Zhi 124true 2014/9/22 0:00:00 JIANG Shu-Hai,FAN Ting,LIU Li-Juan,CHEN Yi,ZHANG Xiao-Qing,SHA Zuo-Liang,LIU Yu-Liang and ZHANG Juan-Kun 123true 2014/7/19 0:00:00 LIU Jing-Fa,SONG Bei-Bei,LIU Zhao-Xia,SUN Yuan-Yuan and Huang Wei-Bo 122true TbZC3H7, TbZC3H34 and TbZC3H5, in Trypanosoma brucei. TbZC3H7, a core component of RNA cap-binding complex, showed a strong RNA-binding ability. TbZC3H34, a hypothetical protein, displayed a weak RNA-binding activity, while one of its interacting proteins showed a strong activity. In contrast, TbZC3H5 and all its interacting proteins did not show any RNA binding activity. These results indicated that CLiTAP is an efficient method and can be used to experimentally identify the RBPs in a protein complex, which provide a basis for further mapping the RNA binding sites and investigating the structure and mechanism of RBPs.]]> 2014/6/18 0:00:00 YUE Sha,ZHOU Shu-Ru and GUO Xue-Min 121true C. elegans. However, it is a challenge to determine the calcium transient in a freely moving worm for two reasons. One reason is the challenge in ensuring the co-expression of the genetically encoded calcium indicator and reference fluorescent protein in the same target neurons. Another reason is the common problem with spectrum cross-talk between the fluorescent pair used most often: G-CaMPs (calcium indicator) and DsReds (the reference fluorescent protein). Spectrum cross-talk occasionally introduces artifacts in the calcium transient measurements. Herein, we developed a novel bicistronic expression strategy to ensure co-expression efficiency and simplify the labeling for the target neurons. Moreover, we presented a new fluorescent protein pair for calcium imaging, mKate2 and G-CaMPs, which have less spectrum cross-talk. We successfully tested our new labeling strategy in the C. elegans ASH sensory neuron. We anticipate that this improved technique will facilitate neural circuit studies in C. elegans.]]> 2014/5/22 0:00:00 ZHANG Hai-Ning,HUANG Wen-Ming,YANG Song and XU Tao 120true Bacillus subtilis. And for the first time we revealed that the bacterial culture exhibited complicated and dynamically distributed multiple heterogeneous subgroups depended on its growth stage. This method has low background noise, high sensitivity and great resolution. The newly identified multiple subpopulations of Bacillus subtilis and their changes dynamically associated with the biological functions are likely to provide new opportunities to understand physiological change patterns and their underlying molecule mechanisms. We also discussed that the new method based on flow cytometric measurements of non-label parameters with high sensitivity and resolution had great potency for studies on the heterogeneity of various microbes.]]> 2014/4/22 0:00:00 LIU Chun-Chun,ZHAO Yun and HANG Hai-Ying 119true 2014/4/22 0:00:00 YANG Gang-Long,MA Tian-Ran and LI Zheng 118true e. g. SL, LNT, and GalNAc) showed increased signal while 5 carbohydrate probes (e. g. Man, Man-9-Glycan, and Xyl) showed decreased signal in HepG2 compared with L02 cell line. Meanwhile, GalNAc staining showed moderate binding to the cytoplasma membrane, central cytoplasm, and perinuclear cytoplasm in the L02, and the binding intensified in the same regions of the HepG2. NeuAc staining showed moderate binding to the cytoplasma membrane, and perinuclear cytoplasm in the HepG2, and the binding intensified in the same regions of the L02. In conclusion, the precision alteration of GBP related to HepG2 may provide useful information to find new molecular mechanism of hepatocellular carcinoma and antitumor therapeutic strategies.]]> 2014/11/21 0:00:00 ZHONG Yao-Gang,QIN Xin-Min,DU Hao-Qi,DANG Liu-Yi and LI Zheng 117true 2015/8/18 0:00:00 FENG Ya-Ning, JIAO Meng-Ying, DUAN Hui-Long and DENG Ning 116true 2015/7/20 0:00:00 ZHANG Yuan-Yuan, HAN De-Ping, DENG Wei-Dong, MAO Hua-Ming, DENG Xue-Gong and DENG Xue-Mei 115true MRR (Mean Rank Ratio) but bigger AUC value. The results are significantly better than other modules-based mining algorithms, and the biological explanations for these mined modules are more significant. More importantly, the NMCOM algorithm can be easily extended to mine any other diseases candidate modules.]]> 2015/4/24 0:00:00 WANG Yi-Bin, CHENG Yong-Mei and ZHANG Shao-Wu 114true 2015/3/24 0:00:00 DENG Li-Li, XU Yan-Jun, ZHANG Chun-Long, YAO Qian-Lan, FENG Li and LI Chun-Quan 113true 2015/2/6 0:00:00 LV Wei-Gang, LI Jie, YANG Fei and WANG Kuan-Quan 112true 2015/1/19 0:00:00 PAN Chao, SU Yun-Cong, YANG Rui, DUAN Hui-Long and DENG Ning 111true 12C₆]- or [¹³C₆]-aniline, and the derivatized glycans were quantitatively analyzed by Matrix-assisted laser desorption/ ionization time of flight mass spectrometry (MALDI-TOF/TOF MS). Finally, 52 N-glycans of the bladder cancer were identified. And the sialic acid as well as the fucosylated in the bladder cancer were found significantly over-expressed. At the same time, the bisecting and high-mannose glycan were also high-expressed in the bladder cancer cells. This study provides some referential significance for the future study on the glycomics of bladder cancer.]]> 2015/12/18 0:00:00 YANG Gang-Long, ZHANG Jia-Xu, LIU Chang-Mei and GUAN Feng 110true 2015/10/21 0:00:00 BAI Jie-Yun, XIE Song-Jun, WANG Kuan-Quan and YUAN Yong-Feng 109true 2016/8/5 0:00:00 LIU Xin-Yu, HAI Xin, SHANG Zhi-Gang and WAN Hong 108true 2016/7/18 0:00:00 LIU Huan-Ling, BAI Jie-Yun, WANG kuan-Quan, LI Qin-Ce and YUAN Yong-Feng 107true v/v) Me₂SO was linear loaded into porcine MⅡ-stage oocyte with the microfluidic device, the intracellular CPA concentration, the cell volumetric changes and the effect on the survival rate and developmental rate of oocytes were investigated and compared with the traditional methods including the one-step method and the step-wise methods. The results showed that the microfluidic method can realize continuous CPA loading to oocytes, reduce the osmotic shock to cells and enhance the cell viability. The lowest penetration volume of oocyte reached 0.86V₀. The cell viability was 92.8% with the microfluidic method, ～33% higher than one-step method, ～16.3% higher than two-step method, and no significant difference with four-step method. After parthenogenetic activation and cultured in vitro, the cleavage rate and the blastocyst rate of oocytes were 75.8% and 27.4%, which were significantly higher than the one-step method and the step-wise methods (P < 0.05). In conclusion, linear loading CPAs with the microfluidic method can significantly alleviate the osmotic damage to oocytes, which may provide a new path for oocyte cryopreservation.]]> 2016/6/21 0:00:00 YANG Yun, ZHOU Xin-Li, DAI Jian-Jun, ZHANG De-Fu, SHAO Wen-Qi, YI Xing-Yue and TAO Le-Ren 106true 2016/3/21 0:00:00 WU Lei, LI Fei, JIN Zhou-Yu, LI Yu-Ting and HU Wei 105true 2016/2/19 0:00:00 WANG Yi-Bin, CHENG Yong-Mei and ZHANG Shao-Wu 104true e.g. sudden death, caused by the dysfunction of sino-atrial node could be treated by implanting electronic pacemakers, which, yet, have many disadvantages, such as the limited life of battery and infections. As a result, bio-pacemakers are expected to replace the electronic devices. In the paper, firstly, the inward-rectifier K⁺ current (I_K1) of the ventricular myocytes is inhibited to make the sing cell show automatic pacemaker activity. And then, based on the data of a human ventricular slice, we create a 2D tissue model of bio-pacemaker to investigate the feasibility of inducing bio-pacemaker in the right ventricle. Based on the model, the effects of electrical coupling and the funny current I_f on the pacemaker are discussed. We find that the pacing capability could be increased by both the weak coupling and strong I_f. However, the weak electrical coupling plays a more important role in the bio-pacemaker.]]> 2016/12/22 0:00:00 ZHANG Yue, WANG Kuan-Quan, YANG Fei and ZHANG Lei 103true 2016/11/22 0:00:00 ZHANG Yao, REN Xiu-Zhi, WAN Yan-Zhou, MA Xiang, ZUO Qing-Li, HAN Jin-Xiang and LU Yan-Qin 102true 2017/9/21 0:00:00 YANG Fei, LV Wei-Gang, ZHANG Lei, ZHANG Yue and LIU Lei 101true P_r). Our results indicated that the Syt1 sgRNA group showed loss of function of Syt1, and had the similar synaptic transmission phenotypes compared to the neurons of Syt1 knock-out (KO) mice; and all the parameters tested had no significance between Scramble group neurons and wild-type (WT) neurons. This study provided evidence for the application of CRISPR/Cas9 technology in acute gene modification in neurons.]]> 2017/6/20 0:00:00 YANG Bo, ZHENG Yi, LU Si-Yao and YAO Jun 100true 2017/6/20 0:00:00 LUO Cun-Jin, WANG Kuan-Quan and ZHANG Heng-Gui 99true 2017/5/22 0:00:00 LIU Fei, ZHANG Shao-Wu and GAO Hong-Yan 98true SNR is increased by 2.90% on average, and the mean square error is reduced by 2.61% on average by using Renyi algorithm. The photoacoustic signal of the pencil (zero-dimension), hair (one dimension) and mouse cortical blood vessels (two-dimensional) was filtered by the Renyi entropy filter before performing the photoacoustic image reconstruction. After Renyi entropy filtering, the contrast of the photoacoustic reconstructed images was greatly improved by 36.75% (pencil cross section, zero dimension), 30.22% (hairline, one dimension) and 30.38% (mouse cortical blood vessels, two-dimensional). The resolution of reconstructed images also increased significantly, but the resolution of mouse cortical blood vessels was limited (17.65%) compared with zero-dimensional and one-dimensional samples. We speculate that this is related to the selection of biological samples (the first two samples were imitation, the samples of mouse cortical blood vessels were in vivo, and the differences in the photoacoustic signals between the mouse cortical blood vessels and the surrounding biological tissues were weaker than those). The signal-to-noise ratio of reconstructed images was significantly increased by 43.20% (pencil cross section, zero dimension), 51.60% (hairline, one dimension) and 48.20% (mouse cortical blood vessels, two dimensions). Finally, the mean square error of reconstructed images decreased by 7.10% (pencil core cross section, zero dimension), 28.57% (hairline, one dimension) and 69.38% (mouse cortical blood vessels, two dimensions), with the increase of the sample dimension, the mean square error of the image is greatly reduced. We assume that this is due to the increase in the size of the sample with the increase of the sample, and the average error of the whole image is reduced, so that the mean square error corresponding to the reconstructed image is reduced.
The experimental results show that the reconstructed images of the photoacoustic reconstructed by Renyi entropy compared with the reconstructed images obtained from the original photoacoustic signal, the contrast ratio of the photoacoustic reconstructed image is enhanced by 32.45%, the resolution is increased by 30.78% and the signal-to-noise ratio is increased by 47.66%, and the mean square error is reduced by 35.01%. The Renyi entropy filter processing algorithm improves the quality of photoacoustic image reconstruction which will help to promote the clinical application of photoacoustic imaging in biomedical diagnosis and treatment, for example, the early diagnosis about the arthritis, breast cancer and epilepsy and other lesions.]]> 2017/11/20 0:00:00 WANG Rong, WANG Yi-Ping, HE Zai-Qian, LUO Cui-Xian, LI Peng-wei, HU Jie, JIANG Hua-bei and ZHANG Wen-Dong 97true 2018/4/27 0:00:00 ZHOU Xin-Li, GUO Ying-Ying, YI Xing-Yue, DAI Jian-Jun and ZHANG De-Fu 96true TrCel12A and TlXynA could be rapidly demonstrated by affinity electrophoresis. The substrate binding affinity can be quantitatively characterized by quantitative regression analysis of the relative mobility of proteins at different substrate concentrations. At the same time, isothermal titration calorimetry and fluorescence spectroscopy were also used to determine the binding affinity of different mutants. For the mutants of TrCel12A, the parameters K_b measured by affinity electrophoresis were significantly related with those determined by isothermal titration calorimetry (R² = 0.82) and fluorescence spectroscopy (R² = 0.83). Therefore, the magnitude of their affinities was TrCel12A-E200Q>W22YE200Q>W22FE200Q>W22HE200Q>W22AE200Q, respectively. Furthermore, the substrate binding affinities of the variants in TlXynA were also characterized using affinity electrophoresis. The results showed that there was a good correlation with that measured by fluorescence spectrometry (R² = 0.84). These results indicate that the parameters K_b measured by affinity electrophoresis can characterize the binding ability influenced by amino acid single-point mutation in active-site architecture of glucoside hydrolase. Therefore, affinity electrophoresis was effective and can be used as routine screening technology in biochemical laboratory to detect the change of series mutants binding affinity in mutant library.]]> 2018/5/18 0:00:00 WU Xiu-Yun, LIU Shu-Ping, ZHAO Yue, CHEN Guan-Jun and WANG Lu-Shan 95true 2018/4/19 0:00:00 TANG Ya-Dong, LIU Xiao, LIU Tai-Gang, XIE Lu and CHEN Lan-Ming 94true 2018/10/8 0:00:00 LIU Qi, XU Ping-Yong and YUAN Lin 93true CCAT2 polymorphisms in one reaction. We designed a pair of primers and three hydrolysis probes including a reference and two competing probes. We successfully discriminated between the three CCAT2 transcript clusters. We took advantage of the cross-reactivity to provide a white space for more visible distinct clusters, although innate rain was detected. Labelling the reference probe with cross-reactivity probe resulted in more distinct clusters than the probe without cross-reactivity.]]> 2018/8/27 0:00:00 SHEN Yang-Li, SUN Hao, CAI Wen-Chen, ZHANG Pin-Zheng, WANG Xu-Ying, SHANG Yu-Han, SHI Lu, XIN Qian-Qian and GUO Zhi-Yi 92true 2018/7/18 0:00:00 WANG Zhu-Lou, KANG Ning, LIANG Yan-Qin, XIAO Qian and HUANG Shao-Hui 91true 2018/10/22 0:00:00 WANG Yi-Ming, WANG Ting, YU Ji, ZHANG Shu and TIAN Ning 90true 2018/5/18 10:13:37 Yan Jie-Xin,Wang Yi and Wang Yun-Fang 89true 2019/9/25 0:00:00 LI Yu-Yu,WANG Guang-Zhi,CHEN Lan-Ming and XIE Lu 88true in vivo. High dynamic range exposure time is set to achieve high-dynamic integrated time modulation, which involves dynamic integrated effect and absorption effect. With this method, each-level vessels can be imaged with similar clarity. Moreover, the vessels in locations with different thickness and absorption coefficient can be reconstructed in the same image. Experiments on phantom and in vivo Gold Pristella Tetra were performed to demonstrate that HDOA can achieve each-level vessels imaging based on dynamic integrated effect and absorption effect.]]> 2019/7/1 11:17:51 ZENG Ya-Guang,LUO Jia-Xiong,HAN Ding-An,XIONG Hong-Lian,WANG Xue-Hua,ZHONG Jun-Ping and WANG Ming-Yi 87true 2019/7/1 11:34:40 YOU Xiu,ZHANG Xiu-Li,LUO Yong,LIU Li-Chao,ZHAO Wei-Jie and LIN Bing-Cheng 86true E. coli, and the purified concatemer thymosin α1 was obtained by one-step heating. Subsequently, the concatemer thymosin-α1 was cleaved into monomers with cyanogen bromide dissolved in 50%-70% trifluoroacetic acid. The thymosin-α1 monomer was further purified by high performance liquid chromatography with purity ≥ 98%. Finally, the obtained thymosin-α1 could stimulate lymphocyte proliferation, which was almost as effective as the commercial thymosin-α1 (Zadaxin?).Finally, The recombinant thymosin-α1 was successfully obtained, which is similar to the commercial one, by genetic recombination, heat purification and appropriate cleavage.]]> 2019/5/22 0:00:00 ZHANG Chong,TIAN Liu-Yang and WENG Hai-Bo 85true ptsG mRNA translation initiation.In this study, Escherichia coli intracellular sRNA SgrS was located visually by smFISH method and super-resolution microscopy technology, and the effects of chaperone Hfq protein and RNase E degrading enzyme on the localization of sRNA SgrS were verified preliminarily. Over-expression of SgrS in E. coli model strain MG1655 (wild strain), sgrS knockout strain (△sgrS) and over-expression strain (△sgrS-pBAD-SgrS) were validated by Northern blot and smFISH methods. sRNA SgrS and ptsG mRNA were located respectively in the wild-type strain, the hfq knockout strain (△hfq) and the rne knockout strain (△rne-710) by smFISH method. Comparing with the wild-type strain, SgrS was mainly located nearby cell membrane, ptsG mRNA was located in bacterial cytoplasm in △hfq and △rne-710 strains by super-resolution imaging, and the copy numbers of both RNA were significantly increased (P＜0.01). These results suggest that the expression levels of SgrS and ptsG mRNA were increased significantly in hfq knockout E. coli and rne-710 knockout E. coli. Integrated application of smFISH method and super-resolution technology found a highly sensitive detection method for the intuitive quantification and localization of bacterial RNA, which can be used for the research of gene regulation functional.]]> 2019/4/19 15:24:23 WANG Jing,RUAN Chong-Mei,BAI Yuan-yuan,HAN Yan-Ping and YANG Rui-Fu 84true 2019/1/18 0:00:00 DANG Dan,XIANG Rong-Wu,LIU Bin,LIU Xiao-Fei and LI Mi 83true etc., for processing reconstructed map. This new method is derived from the solvent flattening method, which is widely used in X-ray crystallography for solving and improving macromolecular phases. In the experiment, we implemented FSC between reconstructed maps, Euler angular error scatter plot etc. methods to assess effect of auto-mask method. It was shown that mask map generated by auto-mask method can soundly cover molecular signal region of reconstructed map, and our new auto-mask method in three-dimensional reconstruction can help to improve resolution of three-dimensional reconstruction.]]> 2020/3/4 11:06:54 SU Rui,ZHANG Shu-Yang and WANG Jia-Wei 82true 2020/6/21 0:00:00 SU Li,XIONG Zhi-Hao,YANG Hao,HUANG Lin and JIANG Hua-Bei 81true 2020/9/18 0:00:00 ZhangYue,Liu Shuyong,Li Jie and Wang Kuanquan 80true 2020/6/10 0:00:00 SHENG Hao,LU Yu-Feng and BAO Yong-Ming 79true 2020/5/13 0:00:00 WEI Yi-Cheng,YU Pei,CHEN Ming,SUN Zi-Ting,ZENG Yan,LOU Ji-Zhong,CHEN San-You,SHI Fa-Zhan and DU Jiang-Feng 78true Brevundimonas, and its sequences were 97.8% similar to Brevundimonas diminuta as well as 98.1% similar to Brevendomonas faecalis, respectively. Antibiotic susceptibility assay showed that “black granules” were sensitive to antibiotics chloramphenicol (25 mg/L), erythromycin (200 mg/L) and tetracycline (2.5 mg/L), but resistant to ampicillin (50 mg/L), puromycin (2 mg/L), penicillin-streptomycin (100×) or gentamicin-amphotericin B (100×). Crystal violet staining showed that the proliferation of “black granules” was inhibited by the chloramphenicol (25 mg/L), erythromycin (200 mg/L) or tetracycline (2.5 mg/L) in the DMEM medium, and the inhibition of “black granules” for cell proliferation were reduced. In summary, the “black granules” isolated and identified in our study was a new stain of Brevundimonas, and the inhibition of “black granules” for cell proliferation could be reduced by low concentration of chloramphenicol, erythromycin or tetracycline. Due to the limitations of this study, there may be other possibilities for the species of “black granules”. This study provides new research ideas and methods for species identification of “black granules” or nanobacteria and sterile culture of cells.]]> 2020/5/12 0:00:00 ZHOU Yi-Ting,GAO Zeng-Hong,YANG Jia-Wen,WANG Jin,GUO Ya-Bin and MA Guang-Wei 77true 2021/3/18 0:00:00 LIU Mei-Jun,YU Ji and TIAN Ning 76true 2021/1/19 0:00:00 Wang Sheng-Xiong,Chen Zhen-Qiang,Han Hua and Guo Ai-Ke 75true 2021/1/19 0:00:00 ZhangZhang,TangYanhong,ZengXinghui,XiongHonglian,ZengYaguang and HanDingan 74true in vivo visual axis parameter (VAP) measurement. In this study, we use two rotating disks to switch the focus position synchronously, to expand the detection depth range. Three parallel glass plates of different thicknesses are placed on a rotating disk along the path of the detection beam, so as to switch the focus position of the probing beam from the cornea, the anterior and posterior of the lens to the retina. On the other synchronously rotating disk, the light path of the reference arm can simultaneously extend the detecting optical path to match the probing beam. This multistage focusing method can make the probing beam completely focused on each segment of the human eye during the course of signal collection. Subsequently, we measured VAP several times, and the results show that our four-focus switch FD-OCT system exhibits good repeatability. In conclusion, we prove theoretically and experimentally that the proposed four-focus switched FD-OCT system can realize whole eye segment imaging and VAP measurement, including central corneal thickness, anterior chamber depth, lens thickness, and axial length. Our method will be beneficial for measurements in ophthalmology.]]> 2021/8/24 0:00:00 LUO Jia-Xiong,LI Jian-Cong,YU Miao,GUAN Cai-Zhong,HUANG Li-Yuan,ZENG Ya-Guang and WU Yan-Xiong 73true 2021/8/24 0:00:00 WEN Hao,WEI Yi-Liang,GUO Xiao-Yuan,SUN Chang-Chun,XUE Si-Yao,LIU Jing,FAN Hong and JIANG Li 72true 2021/7/28 0:00:00 ZHU Ying and SUN Jian-Yuan 71true 2021/6/24 0:00:00 LUO Jia-Xiong,LI Jian-Cong,YU Miao,ZENG Ya-Guang and WU Yan-Xiong 70true 2021/6/24 0:00:00 RUAN Yao,GUO Jun-Ming and XIAO Bing-Xiu 69true 2021/4/26 0:00:00 LI Xiao-Wen,WANG Lu-Quan,ZENG Ya-Guang,CHEN Yun-Zhao,WANG Ming-Yi,ZHONG Jun-Ping,WANG Xue-Hua,XIONG Hong-Lian and CHEN Yong 68true CV-45V for 60 min or 90 min gradient, CV-45V-65V combinations for 120 min or 150 min gradient to obtain the optimal protein identifications, and identified 6 300, 6 994 and 7 500 proteins in 60 min, 120 min and 150 min from 293T proteome, respectively. In FAIMS DIA experiment, we used CV-45V-65V voltage sweeping, 60 isolation windows, and obtained the optimal proteins identifications and quantitative reproducibility. We quantified 7 019 proteins in 293T cell lysate and 1 077 proteins in depleted plasma in 60 min gradient. The combination of APD on, "Precursor Fit" threshold of 70 and Turbo TMT could simultaneously increase the number of protein identifications and the accuracy of TMT quantification. 10 989 peptides and 2 162 protein were quantified in TMT11-plex labeled yeast proteome. Taken together, the various LFQ methods and TMT quantification method optimized in this study showed high performance and various applications in quantitative proteomics.]]> 2021/4/8 0:00:00 ZHOU Yue,YANG Xiang-Yun,HUANG Min,LI Xiang and GUAN Feng 67true in situ imaging in liquids. The morphological differences of exosomes in liquids and in air were revealed. Secondly, the mechanical properties of single living exosomes were quantitatively and visually studied by AFM indentation assays and AFM multiparametric imaging, respectively. Finally, structural and mechanical changes of exosomes after the treatment of chemical fixation were revealed by AFM. The research benefits investigating the structures and properties of living exosomes at the nanoscale for comprehensively understanding the behaviors of exosomes, which will have potential impacts on the studies of exosomes.]]> 2021/4/2 0:00:00 LI Mi,XU Xin-Ning,XI Ning,WANG Wen-Xue,XING Xiao-Jing and LIU Lian-Qing 66true In vivo angiography near chicken embryo heart was performed to demonstrate the efficacy of our method, and it produced clear, blur-free angiograms with high spatial resolution and signal-to-noise ratio.]]> 2021/12/23 13:41:03 WANG Xue-Hua,WENG Jia-Shun,WANG Ming-Yi,HUANG Li-Yuan,XU Xiang-Cong,HAN Ding-An and ZENG Ya-Guang 65true 2021/11/23 0:00:00 WANG Wen-Juan 64true Objective Serum anti-phospholipase A2 receptor antibody IgG (PLA2R-IgG) is an important basis for the diagnosis and treatment of idiopathic membranous nephropathy. By now, its conventional detection method is ELISA. To improve the reaction convenience, and obtain the assay sensitivity and wide detecting range, a novel immunoassay was established for PLA2R-IgG detection.Methods Here, based on europium fluorescent microspheres an indirect immunochromatographic assay (ICA) for PLA2R-IgG was developed and evaluated. The reaction process was firstly chosen, and the method parameters were assessed like pH of activating buffer for microspheres, the ratio of europium microspheres to antibodies, and reaction time.Results The performance metrics of the newly proposed assay were analyzed that the sensitivity was 0.7 RU/ml of PLA2R-IgG, the standard curve equation was y=0.771x－1.437 with 0.995 of R, the linear working range was 0.7-1 500 RU/ml, the recoveries were 86.27%-98.98%, the average variable coefficient of intra assay was 8.13%, the cross reaction ratio were above 0.1% and PLA2R-IgG-ICA reagents were stable for 10 d at 37℃. The correlation was 0.953 between developed method and commercial ELISA kits, the consistency was also high. The positive detection rate was 76.9%.Conclusion The established PLA2R-IgG-ICA using two-step dosing was rapid, sensitive, quantitative and accurate with potential clinical application.]]> 2022/9/21 0:00:00 ZHANG Yi,ZHOU Ying,ZHOU Yan,MA Qi,YE Yan,YIN Hao,YU Lei,ZHOU Bin and WANG Chun-Xin 63true Objective The axial length (AL) and the corneal curvature radius (CR) in the optical biological parameters of the eye can be used as two important parameters for the prevention and monitoring of ocular myopia. In order to improve the speed and accuracy of measuring the length of eye axis and to achieve high precision of corneal curvature simultaneously dynamic measurement, This paper proposes a system for measuring optical biological parameters of the eye based on low-coherence light interference technology.Methods The system uses a rotating optical delay line to quickly change the optical path of the reference light, and uses a standard part with a curvature radius of 8 mm to calibrate the vertex of the human cornea to the distance between the target ring and the interference signal of the cornea trigger the camera and the data acquisition card to achieve synchronous acquisition, thereby realizing rapid measurement of the axial length and precise positioning of the distance between the target ring and the corneal vertex, while ensuring the magnification of the imaging system constant and real-time data collection.Results Experimental results show that this low-coherence optical interferometry system can measure the axial length and corneal curvature radius in real time. The axial length error is less than 40 μm, and the human corneal curvature radius variance is 2.082 36×10^-2 μm.Conclusion The system measures AL and CR quickly and accurately, which may play an important role in the prevention and monitoring of myopia.]]> 2022/9/21 0:00:00 HU Ji-Ye,CHEN Long,HUANG Li-Yuan,DING Wen-Zheng,HUANG Ming-Bin,ZHANG Hao,ZENG Ya-Guang and TAN Hai-Shu 62true Objective In order to prepare ubiquitin samples with different chain types, different chain lengths and phosphorylation modifications.Methods This study mainly uses the biological enzymatic method to describe the preparation routes of the above samples. There are two main methods, the first method is to add ubiquitin monomer one by one and then extend the ubiquitin chain; the second is to prepare mixed polyubiquitin chains through an enzymatic reaction, and then purify and separate these mixed chains.Results The experimental results show that both methods can achieve the purpose of preparing polyubiquitin chains. Further, phosphorylated ubiquitin samples were prepared by phosphorylation of ubiquitin. K11/K48 branched chain ubiquitin was prepared by K11 and K48 ubiquitinase.Conclusion In short, based on the above preparation route of the ubiquitin chain, it is possible to further perform post-translational modifications such as phosphorylation modification on different subunits of different link forms. The site-specific attachment of a prosthetic probe and isotope labeling on different subunits allowed us to perform NMR and FRET measurements. In summary, these methods presented here can provide reference and help for scientists involved in Ub research.]]> 2022/8/19 11:34:39 QIN Ling-Yun,NIE Ze-Feng and TANG Chun 61true Lens culinaris) lectin in nude mice with human liver cancer transplants, there is a lack of research on how the total saponins of Lablab Semen Album affect the growth of the prostate cancer cell line PC-3. Therefore, it is necessary to explore the mechanism through which total saponins of Lablab Semen Album impact the growth of the prostate cancer cell line PC-3.Methods In this paper, the CCK8 method was adopted to test the effect of different concentrations of Lablab Semen Album total saponins on the growth of PC-3 cells. Transcriptomics was used to analyze the molecular mechanism of the inhibition of the growth of PC-3 cells by Lablab Semen Album total sponins, and the related differential gene expression was verified by real-time quantitative PCR and Western blot experiments. Western blot and CCK8 assays were used to detect the survival rate of total saponins in Lablab Semen Album-treated PC-3 cells overexpressing ALDH7A1.Results With increasing concentration of Lablab Semen Album total saponins, the survival rate of PC-3 cells was reduced significantly, and the IC₅₀ value of Lablab Semen Album total saponins was 1 086 mg/L. The transcriptomics sequencing results showed that compared to the control group, there were 2 360 differentially expressed genes in the cells treated with Lablab Semen Album total saponins, of which 1 982 genes were upregulated and 378 genes were downregulated. The GO results showed that the differentially expressed genes were significantly enriched in biological processes closely related to cancer onset and development. In addition, the KEGG analysis results also showed that the differentially expressed genes were enriched in the signaling pathway of tumor metabolism. When the differential genes were further verified, the results showed that compared to the control group, the protein expression levels of ALDH7A1, GCAT and PGAM4 in the prostate cancer cells treated with Lablab Semen Album total saponins were obviously reduced (P<0.05), whereas the protein expression levels of DMGDH and CBSL were significantly increased (P<0.001). According to the results of in vitro cell experiments, the downregulated expression of ALDH7A1 in prostate cancer cells by total saponins of Lablab Semen Album inhibited their growth.Conclusion Lablab Semen Album total saponins may inhibit the growth of prostate cancer cells in vitro through the expression of ALDH7A1.]]> 2022/8/19 0:00:00 Yuan Qiang-Hua and HAN Jun 60true Objective Long non-coding RNAs (lncRNAs) participate in a variety of vital biological processes and closely relate with various human diseases. The prediction of lncRNA-disease associations can help to understand the mechanisms of human disease at the molecular level, and also contribute to diagnosis and treatment of diseases. Most existing methods of predicting the lncRNA-disease associations ignore the deep embedding features hiding in lncRNA/disease network topological structures. Moreover, randomly selecting the negative samples will affect the robustness of predictors.Methods Here we first set up a high quality dataset by using an effective strategy to select the negative samples (i.e., pairs of non lncRNA-disease association) with relatively higher quality instead of randomly selecting the negative samples, then proposed a novel method (called NELDA) to predict the potential lncRNA-disease associations by building 4 deep auto-encoder models to learn the low dimensional network embedding features from the lncRNA/disease similarity networks, and lncRNA-disease association network, respectively. NELDA takes the lncRNA/disease similarity network embedding features as the input of one support vector machine (SVM) classifier, and the lncRNA/disease association network embedding features as the input of another SVM classifier. The prediction results of these two SVM classifiers are fused by the weighted average strategy to obtain the final prediction results.Results In 10-fold cross-validation (10 CV) test, the AUC of NELDA achieves 0.982 7 on high quality dataset, which is 0.062 7 and 0.020 7 higher than that of other two state-of-the-art methods of LDASR and LDNFSGB, respectively. In the case studies of stomach cancer and breast cancer, 29/40 (72.5%) novel predicted lncRNAs associated with stomach and breast cancers are supported by recent literatures and public datasets.Conclusion These experimental results demonstrate that NELDA is a superior method for predicting the potential lncRNA-disease associations. It has the ability to discover the new lncRNA-disease associations.]]> 2022/7/20 0:00:00 LI Wei-Na,FAN Xiao-Nan and ZHANG Shao-Wu 59true Objective In order to construct a viral vector that can simultaneously express two non-fusion proteins in the whole host plants.Methods Agrobacterium infectious clone pYL156 containing tobacco rattle virus (TRV) genomic RNA2 was used to construct dual expression vector pTRV2e² by deleting 279 bp of 5" end of 2b gene, changing initiation codon of 2b gene ATG to AGG, and introducing the subgenomic promoter of pea early-browning virus (PEBV) coat protein (cp) gene. Different exogenous genes were cloned into the downstream of 2b and PEBV cp subgenomic promoters to measure the ability of virus TRVe² to express two foreign proteins, assess the stability of reconstructed TRVe² and analyze the function of proteins in the seedlings of Nicotiana benthamiana.Results TRVe² could simultaneously and rapidly produce two non-fused target proteins and express at least a 70 ku foreign protein in the whole host plants; TRVe² harboring 2.0 kb exogenous gene could stably exist in N. benthamina plants and could be served as technical means for analyzing the biological function of the proteins and the interaction between two proteins.Conclusion Recombinant virus TRVe² constructed in this study provide a toolbox for fast and efficient production of double foreign proteins and for analysis of the interaction between two proteins in the host plants.]]> 2022/7/20 0:00:00 GUO Ge,CHANG Fa-Guang,LAI Jia-Liang,ZHANG Xian-Wen,DU Zhi-You and LIAO Qian-Sheng 58true Objective Nowadays, how to determine an accurate three-dimensional protein structure from nuclear magnetic resonance (NMR) spectroscopy experiments is a hot topic in biophysics, because understanding the spatial structure of a protein is crucial to research its function. However, this is a large challenge due to the serious lack of experimental data.Methods In this paper, the problem of protein structure determination was solved by matrix completion (MC) algorithms of recovering a distance matrix. Firstly, the initial distance matrix model was established, then its missing data were recovered by the MC algorithms at different sampling ratios. The subsequent stage involved adding the noise model to evaluate the noise resistance of the algorithms. Four proteins with different topological structures and 6 off-the-shelf MC algorithms were selected for testing.Results The results show that these algorithms have good performance in a certain range of sampling ratios and noises. More specifically, the advantages of different algorithms in the case of accurate sampling and noisy sampling are compared by analyzing the average and standard deviation of the root-mean-square deviation (RMSD) and computational time, which are two important indexes about algorithms.Conclusion We can conclude that 6 different MC algorithms have different performances and advantages for the problem of protein structure determination. These characteristics provide a basis for the development of a new MC algorithm. The results of this paper have potential promotion in the field of protein research based on MC algorithms.]]> 2022/6/21 0:00:00 LI Zhi-Cheng,WEI Xian and LI Jin-Ting 57true Objective Different patients may have different responses to the same anticancer drug. Understanding differences in anticancer drug responses among patients is crucial for cancer precision medicine.Methods High-throughput sequencing data make it possible to construct anti-cancer drug response classification models. Based on two classic data sets, Cancer Cell Line Encyclopedia (CCLE) and Genomics of Drug Sensitivity in Cancer (GDSC), this paper proposed a classification model, mRMR-SVM, by employing Max-Relevance and Min-Redundancy (mRMR) algorithm and Support Vector Machine (SVM). Feature genes were extracted by using variance ranking and mRMR algorithm on gene expression data,and SVM was applied to predict that an anticancer drug is sensitive or resistant to a given cell line.Results The experimental results showed that the average accuracy of mRMR-SVM is 0.904 for 22 drugs in CCLE, and 0.851 for 11 drugs in GDSC, higher than traditional SVM, Random Forest, Deep Response Forest, Deep Neural Network and CDCN.Conclusion mRMR-SVM also has good generalization due to its satisfactory classification prediction on three specific tissues. In addition, mRMR-SVM could identify biomarkers closely related to the occurrence and development of cancer.]]> 2022/6/21 0:00:00 LI Shao-Da and LI Yu-Shuang 56true Objective We propose a dual-contrast optical projection tomography (DC-OPT) based on principal component analysis (PCA) to obtain a three-dimensional (3D) visualization of the blood-flow network and skeleton in a live organism.Methods The PCA method was used to extract the absorption and flow contrast images (15 images/projection position). The absorption image was obtained with the use of the first principal component of the raw image sequence. The flow images were obtained based on the computation of the modulation depth of each pixel. The flow and absorption contrast images at different projection positions are combined to achieve a synchronous reconstruction of a 3D image.Results The combination of PCA and OPT is used to realize the 3D imaging of the blood-flow network and skeleton of the biological sample by separating the dynamic blood flow signal and the static background signal of the sample.Conclusion The novelty of our study is attributed to the fast, simultaneous, dual-contrast 3D images of the blood-flow network and skeleton by the same optical system. The experimental result can be applied in physiological development studies in live model organisms.]]> 2022/4/22 0:00:00 YANG Xu-Lun,ZHANG Yan-Ting,GUAN Cai-Zhong,ZHANG Zhang,WANG Lu-Quan,YI Min,HAN Ding-An,WANG Ming-Yi,CHEN Yong and ZENG Ya-Guang 55true Objective Protein flexibility plays important roles in various biochemical processes in the living organisms, such as enzyme catalysis, signal transduction, substance transport and storage, etc. Prediction of the intrinsic flexible motions based on the tertiary structure of proteins is helpful for our better understanding of the mechanism of protein functions, which is an important scientific problem in the research field of protein structure-function relationship. Convolutional neural network (CNN), one of the mainstream algorithms in deep learning, has been successfully applied in the study of protein structure-function relationship.Methods In the present work, based on the idea of PointNet method developed in the computer vision research, a CNN model was proposed to predict the protein flexibility. In this model, protein structures were treated as three-dimensional point clouds, where the atomic coordinates of proteins were directly inputted into the model, and the permutation invariance and global rotation invariance of the point cloud were delt with by using the pooling operations and a spatial transformation network, respectively. In addition, considering the varied sizes of different proteins, a new mini-batch optimization strategy was proposed, where the model was trained by using the mini-batches of protein structures with different sizes as input. The Pearson correlation coefficient was used as the evaluation function for the training of the model. Besides that, in order to further enhance the performance of the network, an improved model was constructed based on the PointNet-based CNN model, in which the max-pooling and the average-pooling were concatenated to better extract the global features of protein structures. Then the PointNet-based CNN model and the improved model were trained and tested by using the temperature factors (B-factors) of 243 non-redundant proteins.Results The results show that the average Pearson correlation coefficient between the predicted and the experimental temperature factors predicted by the PointNet-based model and the improved model were 0.64 and 0.65, respectively. The prediction accuracy of our models is better than that of the Gaussian network model that has been widely used in investigating protein flexibility. Especially, for the 74 relatively loose natural disordered proteins from the Disbind website, the average Pearson correlation coefficient predicted by our models were 0.62 and 0.64, respectively, which were significantly better than GNM.Conclusion Our studies provide an effective model for the effective prediction of the intrinsic flexibility encoded in protein structures.]]> 2022/3/21 0:00:00 ZHANG Xiao-Hui,GU Hao-Sheng and WANG Zhi-Ren 54true Objective Cell mechanics plays an important role in cellular physiological and pathological processes and is closely related to the health states of living organisms. Investigating cell mechanics significantly benefits revealing the underlying mechanisms guiding life activities. The advent of atomic force microscope (AFM) provides a novel instrument for single-cell assay. AFM is able to not only visualize the morphology of singe living cells under aqueous conditions with high resolution, but also quantitatively measure the mechanical properties of cells. Utilizing AFM to investigate the mechanics of individual cells has achieved great success in the past decades, which provides numerous new insights into cellular physiological and pathological processes and has become an important tool in the field of life sciences. However, due to the fact that AFM probe itself is unable to perform drug delivery, so far it is still challenging for the simultaneous measurements of cell mechanics by AFM in response to the stimulation of ultra-trace drug. Here, by combining micropipette and AFM, a method allowing single-cell precise drug delivery and simultaneous measurements of cell mechanics is presented.Methods The micropipette-based single-cell microinjection system was built on an inverted fluorescent microscope by using a 3D manipulator, a micropump, a syringe, a PTFE tube and a micropipette. The micropipette was obtained from the glass capillary by using the micropipette puller. NIH 3T3 cells (mouse embryonic fibroblast), HEK 293 cells (human embryonic kidney cell) and MCF-7 cells (human breast cancer cell) were used for the experiments. Under the guidance of optical microscopy, staining reagents or drug molecules were delivered to individual cells, and then AFM probe was moved to the targeted cells to obtain force curves. Cellular Young’s modulus was calculated from the force curves by applying Hertz-Sneddon model.Results The effects of the pore size of micropipette tip on cell injection were analyzed firstly, and the results showed that larger pore size tip (the outer diameter of the tip was larger than 1 μm) could cause obvious mechanical damage to the cell. Then blue ink or PI staining solution was injected to single cells by micropipette under the guidance of optical microscopy, and the recorded optical/fluorescent images after injection clearly showed that the targeted cells were successfully injected. Finally, micropipette was integrated with AFM to measure the Young’s modulus changes of single cells after the treatment of chemotherapeutic drug (cytarabine), and the results showed that stimulation of cytarabine could cause the changes of cellular mechanical properties.Conclusion Combining micropipette and AFM enables applying precise chemical stimulation to a single cell while simultaneously measuring cellular mechanical properties after chemical stimulation, providing a novel idea for single-cell mechanical analysis in response to ultra-trace drugs.]]> 2022/2/21 0:00:00 FENG Ya-Qi,YU Peng,SHI Jia-Lin and LI Mi 53true Objective Diffuse optical tomography (DOT) has low signal-to-noise ratio in the detection of big breasts in women, resulting in low imaging resolution. This paper proposed a way to improve the resolution of diffuse optical tomography, based on the computed tomography laser mammography (CTLM).Methods All experiments in this paper were phantom experiments. Firstly, this paper explored the effects of phantom diameter and target depth on the resolution of DOT. Secondly, this paper proposed to use the flexible photosensitive resin to make the outer covering part through 3D print, then use the outer covering part to constrain the measured object to reduce the diameter of the measured object to optimize the resolution of DOT, after verifying that the outer covering part had no significant effect on the resolution of DOT.Results In this paper, it was verified by phantom experiments that the changes of the phantom diameter and the target depth would affect the imaging resolution. With the increase of the phantom diameter, the wide-axis FWHM and the long-axis FWHM of the ROIs (region of interests) basically showed an upward trend. With the increase of the target depth, it was also affect the wide-axis full width at half maximum (FWHM) and the long-axis FWHM of the ROIs. The experimental results aslo found that the diameter of the phantom had a significant effect on the long-axis FWHM of the ROIs, and the target depth has a significant effect on the wide-axis FWHM of the ROIs. In addition, the results of the phantom experiment verified that the outer covering part had no significant effect on the resolution of DOT. Simultaneously, after compressing the measured object with the outer covering part, the long-axis FWHM of the ROIs decreased significantly, and the reduction reached more than 30%, which was much larger than the wide-axis FWHM of the ROIs. It was confirmed that it could achieve the effect of improving the imaging resolution by using the outer covering part to constrain the measured object.Conclusion The way proposed in this paper can achieve the effect of improving the resolution of breast diffuse optical tomography, and the materials and methods used were simple and had strong practicability, which provided a new idea for improving the resolution of breast diffuse optical tomography.]]> 2022/12/20 0:00:00 LI Lun,WU Dan,WEN Yan-Ting,CHEN Yi,CHI Zi-Hui,TIAN Yin and JIANG Hua-Bei 52true Objective Diabetic retinopathy (DR) is a serious complication of diabetes that may cause vision loss or even blindness in patients. Early examination of the choroid plays an essential role in the diagnosis of DR. However, owing to the fuzzy choroid-sclera interface (CSI) and shadow of retinopathy in the optical coherence tomography (OCT) images of DR, most existing algorithms cannot segment the choroid layer precisely.Methods In this paper, we propose an optimized squeeze-excitation-connection (SEC) module integrated with the UNet, called the SEC-UNet, which not only focuses on the target but also jumps out of the local optimum to enhance the overall expressive ability. The present paper aims to improve the accuracy of choroid segmentation in DR OCT images.Results The experimental results show that the area under the ROC curve (AUC) of the SEC-UNet reaches up to 0.993 0, which outperforms that obtained for conventional UNet and SE-UNet models. It indicates that the SEC-UNet can obtain accurate and complete segmentation results of the choroid layer. Statistical analysis of choroid parameter changes indicated that compared with normal eyes, the 1 mm adjacent area of choroid fovea increased in 87.1% of DR patients. It proved that DR is likely to cause choroid layer thickening.Conclusion Our method may become a useful diagnostic tool for doctors to explore the function of the choroid in the prevention, pathogenesis, and prognosis of diabetic eye disease.]]> 2022/12/20 0:00:00 XU Xiang-Cong,CHEN Jun-Yan,WANG Xue-Hua,LI Rui,XIONG Hong-Lian,WANG Ming-Yi,ZHONG Jun-Ping,TAN Hai-Shu,ZHENG Yi-Xu,XIONG Ke and HAN Ding-An 51true Objective Cell mechanics plays an important role in regulating cellular physiological and pathological processes and investigating cell mechanics is meaningful for revealing the underlying mechanisms guiding life activities. The advent of atomic force microscopy (AFM) provides a novel powerful tool for single-cell studies and AFM-based indentation assay has become an important method for characterizing cell mechanics in the field of life sciences, yielding numerous new insights into single-cell behaviors. However, current studies of cell mechanics by AFM are commonly performed in static environment, while cancerous cells are in flow environment of vascular fluids during tumor metastasis, and thus the results obtained in static environment cannot completely reflect the real behaviors of cancerous cells in fluidic condition. Particularly, so far knowledge of the mechanical mechanisms guiding the interactions between fluidic microenvironment and cancerous cells in the process of tumor metastasis is still limited. Here, based on AFM, a method allowing measuring the mechanical properties of single cells in fluidic environments is developed.Methods A fluidic cell culture medium device was established on a petri dish with openings on both sides with the use of an injection pump and an extraction pump. The fluidic cell culture medium device was integrated with AFM to measure the mechanical properties of cells in fluidic environments. The fluidic cell culture medium device was also integrated with inverted optical microscope which had a heating plate to observe the growth states of cells in fluidic environments. MCF-7 cells (human breast cancer cell) and HGC-27 cells (human gastric undifferentiated carcinoma cell) were used for the experiments. The fluidic cell culture medium device was used to grow cells to examine the effects of medium flow rate and flow time on cell proliferation and cell mechanics. Under the guidance of optical microscopy, AFM probe was moved to cells grown in static culture medium or fluidic culture medium to perform indentation assay to record force curves, and then Hertz-Sneddon model was applied to analyze the force curves to obtain the Young’s modulus of cells. Calcein fluorescein was used to stain live cells and PI fluorescein was used to stain dead cells. The cytoskeleton changes of MCF-7 cells after growth in fluidic culture medium were observed by confocal fluorescence microscopy.Results The effects of fluidic culture medium on the growth of cells were firstly analyzed. Experimental results on cell growth show that cell culture medium fluidic environment could better promote cell growth and proliferation compared with cell culture medium static environment. Then the mechanical properties of cells grown in static culture medium and fluidic culture medium were measured respectively. Experimental results show that, when the growth condition of cancerous cells changed from static to fluidic, the Young’s modulus of cancerous cells decreased significantly and cytoskeletons reorganized, indicating the influence of fluidic environment on the mechanics of cancerous cells.Conclusion Combining AFM with fluidic control techniques allows detecting the mechanical properties of single cells grown in fluidic environments, providing a novel way to investigate the mechanical cues involved in the interactions between fluidic microenvironments and cancerous cells during tumor metastasis.]]> 2022/10/21 0:00:00 WEI Jia-Jia,LI Mi,FENG Ya-Qi and LIU Lian-Qing 50true Objective Cryopreservation of testicular tissue for later transplantation is another effective way to maintain male fertility.Methods In this paper, the procedure of slow freezing of massive testicular tissue was optimized by shortening the loading time of cryoprotectant (CPA), increasing the freezing rate at the first stage, and directly plunging into liquid nitrogen at the second stage. The mouse testis was cryopreserved by modified two-step freezing. In addition, ice seeding procedure was applied at different temperatures in order to reduce CPA concentration required for cryopreservation of testicular tissue.Results The results showed that negative rate of apoptosis of germ cells in frozen tissues with modified two-step method was significantly higher than commonly used slow freezing method, and had no significant difference with control group. Among them, the negative rate of spermatogonial cells was 98.4%, that of spermatoblast cells was 99.2%, that of sperm cells were 88.4%, and that of sertoli cells was 98.1%. Compared with non-seeding group, seeding at -10℃ can improve the survival rate of testicular tissue that frozen with 5% DMSO. The negative rate of apoptosis were 92.1% (spermatozoa), 93.2% (spermatocytes) and 88.9% (Sertoli), which are not significantly different from that of 10% DMSO group. This indicates ice seeding can reduce the CPA concentration and toxic damage.Conclusion Modified two-step freezing and ice seeding improve the quality of mouse testicular tissue after freezing, and provide a reference for freezing of human testis in clinical.]]> 2022/10/21 0:00:00 TAN Jia,GUO Ying-Ying and ZHOU Xin-Li 49true Objective The correlative cathodoluminescence (CL) imaging is a high-resolution fluorescence imaging technique using electron beam as excitation source. However, the sensitivity of biomaterials to electron irradiation limits the wide application of CL technique in life science. In order to study and develop the application of CL technology in biological samples, this paper aims to deeply understand the excitation characteristics of organic fluorophore by electron source by exploring the structural damage of carbon substrate, degradation of organic groups and fluorescence quenching caused by electron irradiation.Methods We used a CL and electron microscopy (CCLEM) technique in a field emission scanning electron microscope (SEM) to observe organic fluorophores and fluorescently labeled cells.Results We studied excitation and emitting characteristics of organic fluorophores by electron beam. Under the irradiation of low energy (2.5-5 keV) and low current (~10 pA), the fluorescent microbeads had the stronger and stable CL emission, the resolution of CL image reached ~30 nm. After 12 min irradiation, fluorescence intensity of microbeads decreased by 25%, and CL image still maintained acceptable fluorescence intensity and adequate signal to noise ratio. Further, fluorescently labeled subcellular structures were identified from cell surface to a certain depth inside the cell. The nuclei and organelles were well observed with a bulk-sample imaging setup, while membrane proteins, that are widely localized on the cell surface, were clearly identified with a home-made imaging setup of thin-sample.Conclusion Results provide data and technical support for the application of CCLEM in the study of biological structures. CCLEM bioimaging can also be used as an important supplement to correlative light and electron microscopy (CLEM) technique.]]> 2023/8/14 11:16:01 LI Chang-Shuo,LI Shuo-Guo,JI Gang,WANG Li,LI Jin-Tao,WANG Li,JIA Xing,ZHANG Xiao-Yun,HAN Xiao-Dong,JI Yuan and SUN Fei 48true Objective Cell mechanical property plays an essential role in regulating cellular physiological and pathological processes and investigating cell mechanical property offers novel opportunities for revealing the underlying mechanisms guiding life mysteries and human diseases. The advent of atomic force microscopy (AFM) provides a powerful tool for characterizing the mechanical properties of individual cells. The unique merit of AFM is that AFM is able to probe the mechanical properties of single living cells in their native states with high precision (nanometer spatial resolution, piconewton force sensitivity) under aqueous conditions without any pretreatments. AFM-based indentation assay has now become an important method to detect cell mechanical property in the field of life sciences. However, current studies of single-cell mechanical assays based on AFM mainly rely on manual operation, particularly the operator needs to move the AFM probe to the specific position of the target cell to perform indentation assay during experiments, causing that the experimental procedures are quite time-consuming and labor-intensive with low efficiency. Here, a method combining AFM with optical image automatic recognition is developed for rapid measurements of single-cell mechanical property.Methods The UNet++ deep learning model and the template matching algorithm were used to identify the cells and AFM probe in the optical images, allowing automatically determining the positional relationship between the target cell and AFM probe. The AFM probe was then moved to the target cell to perform indentation assays based on the recognition results. A single microsphere was glued onto the AFM probe cantilever to prepare the spherical probe. Two types of cells, including HEK 293 cell (human embryonic kidney) and MCF-7 cell (human breast cancer cell), were used for the experiments. The Hertz-Sneddon model was applied to analyze the force curves obtained during indentation assays to obtain the Young’s modulus of cells.Results The AFM probe could be accurately moved to the target cell (HEK 293 or MCF-7 cell) to measure the mechanical properties of the cell based on the automatic recognition of cells and AFM probe in the optical images. The experimental results also show that the method developed here is not only suitable for conventional conical tips, but also suitable for spherical tips.Conclusion Combining AFM with optical image recognition significantly improves the efficiency of AFM-based single-cell mechanical assay, which provides a novel idea for high-throughput automated detection of single-cell mechanical property and will have active impacts on the studies of cellular mechanical properties.]]> 2023/8/14 11:16:21 Lü Xiao-Long,WEI Jia-Jia,ZHANG Zhi-Hui and LI Mi 47true Objective Detecting the detailed behaviors of single viruses is essential for uncovering the underlying mechanisms guiding virus life cycle, which significantly benefits developing therapeutic methods against viral infection. The advent of atomic force microscopy (AFM) provides a novel powerful tool to characterize the structures and mechanical properties of single viruses with unprecedented spatial resolution, and applications of AFM in single-virus assay have contributed much to the field of physical virology. Nevertheless, the mechanical cues of single native viruses during viral activities are still not fully understood, and particularly studies of utilizing multiparametric AFM imaging to investigate the behaviors of single viruses are still scarce. Here, multiparametric AFM imaging was combined with AFM indentation assay to investigate the structural and mechanical dynamics of single native virus particles in response to chemical stimuli under aqueous conditions.Methods The poly-L-lysine was used to coat the coverslips to attach lentivirus particles onto the coverslips, and then the virus particles were probed by AFM in pure water. Single virus particles were imaged at the peak force tapping (PFT)-based multiparametric AFM imaging mode, in which the topographical images and mechanical maps of the virus particles were obtained simultaneously. Under the guidance of AFM’s topographical imaging, the AFM probe was moved to the central area of the virus particle to perform indentation assay for measuring the mechanical properties of the virus. The alcohol solution (75%) was used as an example of chemical stimulus to treat virus particles, after which the structural and mechanical changes of individual virus particles were revealed by AFM.Results The structures and mechanical properties of single virus particles could be well characterized by AFM under aqueous conditions, and the virus particles exhibited different elastic and adhesive properties in air and in liquid. After the treatment of alcohol, the shape of virus particles became irregular, and the virus particles became stiffer as well as less deformable.Conclusion The research provides a novel way to investigate the structures and nanomechanical properties of single native viruses in liquids based on AFM, which will have general implications for the field of virology.]]> 2023/7/19 12:03:54 YANG Yan-Qi,FENG Ya-Qi,WEI Jia-Jia and LI Mi 46true Objective Tunneling nanotubes are membrane-tubule-like structures that exist between cells and have a direct long-distance biological information exchange function. Because the structure of TNTs is easily destroyed, exists for a short period of time and is unstable after formation, it is difficult to observe its dynamic formation and function. This study used the high content analysis system (HCA) combined with laser scanning confocal microscopy (LSCM) to try to observe the dynamic process of TNTs formation and its function of vesicular material transport.Methods Human lung adenocarcinoma A549 and cisplatin-resistant A549/DDP cells were labeled using fluorescent probes. Subsequently, HCA was used to observe the formation process of TNTs, LSCM to observe the three-dimensional structure of TNTs, and HCA combined with LSCM to analyze the vesicular material transport function of TNTs, respectively.Results TNTs structures can be formed between tumor cells of the same types (A549 or A549/DDP) or between different subtypes of tumor cells (A549 and A549/DDP). TNTs formed between A549/DDP cells were longer, thicker and had a higher formation index compared to A549 cells ( the length, diameter and formation index of TNTs for A549 and A549/DDP were 14.71 μm, 2.27 μm, 4 and 25.44 μm, 2.59 μm, 11, respectively). TNTs are formed in two steps: first, two cell cytoplasmic membranes first come into contact with each other and then fuse, and as the two cells translocate in opposite directions, the fused regions of the membranes are continuously elongated and narrowed, resulting in the formation of TNTs; second, two cells extend filopodia-like membrane projections and fuse when they come into contact with each other’s membrane projections, resulting in the formation of TNTs or one cell extends filopodia-like membrane projections and fuses after contacting the other cell membrane, thus forming TNTs. The transport of vesicles by TNTs is bidirectional. During transport, the rate and amounts of vesicles being transported vary depending on the stage of transport and the donor cell. The vesicular translocation from A549/DDP cells to A549 cells showed a fast initial rate and a slow terminal rate. A549 cells, as donor cells, transit vesicles to recipient A549/DDP cells in a higher number and proportion than A549/DDP as donor cells in the opposite direction.Conclusion The dynamic formation process and vesicular substance transport function of TNTs could be observed and analyzed by HCA combined with LSCM effectively.]]> 2023/7/19 12:03:58 PAN Peng-Yu,ZHAO Qiu-Yu,WANG Ying,WANG Jian-Bo,LI Xiang,LIU Chun-Ying and WANG Chun 45true Objective It is an urgent need for patients with mechanical ventilation and clinicians to monitor the process of pulmonary ventilation with real-time continuous images at the bedside. Electrical impedance imaging (EIT) of the lung can reflect the distribution of changes in the electrical characteristics of the chest caused by breathing, which has a natural advantage in the monitoring of pulmonary ventilation. The purpose of this paper is to establish a radial basis function neural network (RBFNN) based weighted frequency-difference EIT (wfd-EIT) method to achieve high spatial resolution imaging of pulmonary ventilation.Methods The wfd-EIT method was used to describe the conductivity distribution of the thoracic cavity in real time, and then the target region was visualized and its boundary information was accurately identified by the RBFNN. Firstly, through numerical analysis and simulation, 2 028 simulation samples were established by COMSOL and MATLAB software at each excitation frequency, which were divided into training set and test set to verify the feasibility and effectiveness of the proposed imaging method. Secondly, in order to verify the simulation results, a lung physical model was established. Biological tissues with low conductance characteristics were selected to simulate the ventilation area of the lung, and the imaging experiment was conducted on it. The quantitative data of image correlation coefficient (ICC) and lung region ratio (LRR) were used to measure the accuracy of the imaging method.Results The wfd-EIT method can reconstruct the image at any time and accurately reflect the electrical characteristics distribution of the target region. The algorithm based on RBFNN can enhance the imaging accuracy of the target region with ICC reaching over 0.94, which can better highlight the boundary contour information.Conclusion The wfd-EIT imaging method utilizes the simultaneous measurement of multi-frequency impedance spectra to realize rapid visualization of the target area, and combines the advantages of the RBFNN in approximating arbitrary non-linear functions to achieve accurate identification of the electrical characteristics changes in the target area, which lays theoretical and technical foundations for EIT image monitoring of clinical pulmonary ventilation in the next step.]]> 2023/7/19 12:04:26 BAI Shi-Zhan,LI Wen-Sheng,LIN Hai-Jun,LI Jian-Min,ZHANG Fu and YANG Yu-Xiang 44true Objective To study the spatial correlation of the nerve fibers and blood vessels in the auricular skin by using the combination of histological staining technique and tissue clearing strategy.Methods The anterior and posterior auricular skins were carefully peeled away from the intervening cartilage and the auricular nerve fibers and blood vessels were directly immunofluorescent stained with protein gene product 9.5 (PGP 9.5) and phalloidin followed with tissue clearing treatment. After that, these auricular skins were mounted on the microscope slide in the whole mount pattern and examined under an epifluorescence microscope and a laser scanning confocal microscope.Results It was shown that the PGP 9.5+ nerve fibers aligning with phalloidin-labeled blood vessels ran from the base part of auricle to its peripheral region, forming the neurovascular network in the auricular skin. Beyond the conventional immunofluorescence staining, the additional tissue clearing treatment demonstrated the auricular nerve fibers and blood vessels better in morphological detail.Conclusion From the perspective of methodology, tissue clearing technique enhance the visualization of the immunofluorescence labeling within the auricular skin, which should be an effective approach for insight into the auricular neurovascular network in a three-dimensional view under the physiological and pathological conditions.]]> 2023/6/20 16:51:44 ZHANG Kai-Wen,GUO Ya-Ting,SU Yu-Xin,WANG Yu-Qing,CUI Jing-Jing,ZHANG Jian-Liang,WANG Jia and BAI Wan-Zhu 43true Objective The online detection of thrombus and visualization are of great importance in the extracorporeal circulatory system. In this paper, a noninvasive and online detection method of thrombus in extracorporeal circulation based on electrical impedance tomography (EIT) is proposed.Methods Firstly, this paper investigates the effect of sensor size on the imaging performance through joint simulation. Secondly, a 16-copper electrode EIT sensor with a diameter of 20 mm is designed based on the simulation results, a cyclic flow experimental platform is built, and static and cyclic flow experiments are designed. Instead of thrombus, pig blood clots of 3-6 mm in size are placed in fresh pig blood samples and image using the Tikhonov regularization algorithm. The 3 mm and 5 mm clots are placed in the circulation system, and the images of the size and position of the clots in the sensor section are reconstructed by the EIT system and compared with the results taken by the high-speed camera.Results The simulation results show that the image correlation coefficients (IC) are greater than 0.06 for the sensor diameters of 20 mm and 30 mm when the target-to-sensor area ratio (AR) is not less than 0.01, and the imaging effect is well. The static imaging results show that the relative size coverage ratio is less than or equal to 0.1. The circulating flow experiments show that the normalized relative conductivity value changes of 80 and 200 are detected as the clots pass through the sensor, and the results show that the method is capable of detecting clots in the circulatory system.Conclusion The method has the advantages of real-time and noninvasive, and is expected to be applied to the detection of thrombus in vitro.]]> 2023/6/20 16:51:51 ZHANG Jia-Hui,GAO Gui-Feng,WU Yang,ZHOU Tong,LIU Kai and YAO Jia-Feng 42true Objective Single-cell growth detection can more scientifically reveal the rules of microbial metabolic changes and guide later microbial engineering applications. To study the accurate detection of microbial growth during the food safety period and optimal edible period, a single-cell growth detection method based on Raman technology is proposed in this paper.Methods First, a total of 900 single-cell Raman spectroscopy (SCRS) data were collected from two batches of Bacillus subtilis through a simultaneous culture experiment, of which 600 were used for training and testing and the other 300 for model validation. Secondly, based on the feature relationship matrix of principal component analysis, CP-SP feature evaluation method was proposed to screen SCRS features for model detection. Then, a detection model based on XGBoost was built, and grid search and cross-validation were applied to optimize the detection model. Finally, confusion matrix and ROC curve were used to evaluate the detection accuracy, sensitivity and specificity of the model for cell lag phase, log phase and stationary phase.Results The experiment found that the classification performance of the first, second, and fourth principal components screened by CP-SP was improved by 3.1% compared with the first three principal components of the feature contribution rate. The test accuracy of the optimized cell growth detection model was 96.0%, and the verification accuracy was 92.3%.Conclusion The results show that the single-cell growth detection method based on Raman technology can accurately identify the single-cell growth state and has a high generalization ability, which can provide scientific guidance for the formulation of precise regulatory mechanisms for food safety and preservation.]]> 2023/6/20 0:00:00 LI Xin-Li,ZHANG Xin-Yu,YANG Qiang and LI Su-Yi 41true Objective In homeostatic conditions the peritoneal cavity is populated by resident macrophages. Inflammatory stimuli trigger a phenomenon called macrophage disappearance reaction (MDR), during which resident macrophages become irretrievable from the lavage of the serous cavity. This phenomenon was already observed after different inflammatory insults , but is still incompletely understood. MDR can be associated with cell death, adhesion to neighbouring tissues or migration to the draining lymph nodes or the omentum. MDR is a strategy to face and annihilate the infection by which macrophages, under the control of GATA6, move from the peritoneum to the closest tissues in order to alert the immune system. However, the specific distribution of peritoneal macrophages in MDR is still unclear. In our study, peritoneal macrophages labelled with cell membrane green fluorescent dye DiO were used to study the tracking of peritoneal macrophages in the macrophages disappearance reaction.Methods Peritoneal macrophages labelled with DiO were transplanted to C57BL/6 mice. The macrophage disappearance reaction was induced by lipopolysaccharide (LPS) in vivo. Fluorescence microscope and flow cytometry were used to detect the number and fluorescence intensity of DiO-labelled peritoneal macrophages. The tissues of mice were separated and collected, and frozen sections were made to detect the distribution of DiO-labelled peritoneal macrophages.Results The observation by fluorescence microscope and flow cytometry showed that intraperitoneal injection of LPS could significantly reduce the number and fluorescence intensity of DiO-labelled peritoneal macrophages. Peritoneal macrophages that disappeared during the macrophage disappearance reaction were found distributed in the liver, thymus and spleen by frozen sections. DiO labelling peritoneal macrophages does not affect cell viability and with long-term stability in vivo, indicating that DiO may be a safe and effective green fluorescent dye for tracking the distribution of peritoneal macrophages.Conclusion This research method will provide a convenient and effective experimental means for exploring the dynamic changes and related biological phenomena of peritoneal macrophages during MDR. Furthermore, it laid a foundation for further research on the causes and mechanisms of MDR.]]> 2023/3/22 0:00:00 LIANG Jing-Rong,MAI Feng-Yi,SHU Jun-Xiang,GUO Jie,LIAO Xiang,XIAO Li-Zu and LI Chen-Guang 40true Objective Long non-coding RNA play an important role in genetics, metabolism and gene expression regulation. But it is time-consuming and costly to analyze the RNA structure by experimental approaches. However, prediction software based on co-evolutionary algorithm has not made breakthrough progress in prediction accuracy in recent ten years. Therefore, it is necessary to propose a new prediction algorithm to accurately predict the tertiary structure of RNA. So, this paper develops prediction method of base contact map of RNA that can be used to improve the accuracy of tertiary structure prediction.Methods To utilize the physical and chemical characteristics of RNA, we propose a deep learning algorithm based on multi-layer convolutional neural network and long short-term memory hetworks to predict the contact map between base pair. In addition, we employ attention mechanism to deal with complex global spatial independence features in RNA sequences.Results By combining multilayer neural networks with the attention mechanism, our method can effectively obtain local and global information in RNA features, which improves the robustness and generalization ability of the model. The computations show that the proposed model achieves 0.84, 0.82, 0.82 and 0.75 prediction accuracies for the base contact map of 4 criteria (L/10, L/5, L/2, L) of sequence length L.Conclusion Prediction method based on attention method is better than traditional computational methods and common deep learning algorithms, respectively.]]> 2023/3/22 0:00:00 CAO Yi-Hang and HUANG Qiang 39true Objective Primary liver cancer is a common malignant tumor, seriously threatening people’s life and health. According to the differences in pathogenesis, treatment and prognosis, primary liver cancer can be divided into hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC) and other rare types. Among which HCC accounts for 85%-90%. HCC is usually treated by transcatheter chemoembolization (TACE) or minimally invasive ablation, with good prognosis. While ICC and HCC-ICC mixed type have a high degree of malignancy and are generally treated by surgical resection or liver transplantation, with poor prognosis. In order to improve the diagnostic accuracy of HCC patients, primary liver cancer is usually clinically divided into HCC and non-HCC categories, that is non-HCC includes ICC, HCC-ICC mixed type and other rare tumors. Therefore, accurate screening of HCC from liver cancer lesions is of great clinical significance for the treatment of HCC patients. However, due to the high heterogeneity of tumors, the shape, texture, location and blood flow of liver lesions show complexity and diversity in B-ultrasound and contrast-enhanced ultrasound (CEUS) images. Radiologists need to rely on the naked eyes to obtain multidimensional information at the same time, and evaluate diseases according to different characteristics, which requires high level of expertise and clinical experience. Diagnosis results depend on personal subjective factors, which may lead to some HCC mixed into non-HCC categories, and the detection sensitivity of HCC is not high. In this paper, deep convolutional neural network is used to automatically learn the characteristic information of B-ultrasound and CEUS images, and realize the classification of liver cancer.Methods Multiple 2D (VGG, ResNet, DenseNet) and 3D (3D-CNN, Res3D, Dense3D) classification models based on convolutional neural network (CNN) were established and validated, and the B-ultrasound and CEUS images of 116 patients (including 100 HCC and 16 non-HCC patients) were quantitatively analyzed, and the classification performance of each model was compared and analyzed.Results The experimental results showed that the 3D CNN models was superior to the 2D CNN models in all aspects of performance, which verified that the 3D CNN model could simultaneously extract 2D image features and dynamic changes of blood flow in tumor regions, and was more suitable for classification of HCC and non-HCC. The AUC, accuracy and sensitivity of 3D-CNN model are the highest, reaching 85%, 85% and 80%, respectively. In addition, due to the imbalance between HCC and non-HCC samples, the classification performance of the network can be improved by expanding the number of non-HCC samples.Conclusion The 3D-CNN model proposed in this paper can achieve rapid and accurate classification of liver cancer, and is expected to be applied to assist clinicians in the diagnosis and treatment of liver cancer.]]> 2023/3/22 0:00:00 LI Rui,XU Xiang-Cong,LIN Jing-Yi,HUANG Liang-Hui,ZENG Ya-Guang,ZHENG Wei,Chen Guang-Yi,WANG Xue-Hua and HAN Ding-An 38true Objective Acoustic resolution-based photoacoustic endoscopy is a promising functional imaging technique with its large focusing depth. It is widely used in endoscopic imaging of the rectum and esophagus. Acoustic resolution-based photoacoustic endoscopy imaging usually adopts the lateral scanning method based on a single focused ultrasonic sensor, while using the traditional B-mode method for reconstruction, which will greatly reduce the image quality. In order to obtain high-quality images, several dynamic focusing photoacoustic endoscopic imaging algorithms are proposed in this paper.Methods Numerical simulations were performed using these algorithms. In addition, photoacoustic endoscopic imaging experiments were conducted on the phantom to verify the results of the simulation experiments. In the simulation experiments, photoacoustic endoscopic imaging experiments with a focused transducer were simulated. We chose nine points including the focal point as the targets for reconstruction in the imaging area. The characteristics of each algorithm were compared in terms of imaging effect, resolution and signal-to-noise ratio. We made a phantom to verify the imaging effects of several algorithms using a photoacoustic endoscopic imaging system. Several metal wires were inserted in it to simulate targets at different distances and shapes. We compare the advantages of these algorithms over the B-mode method in reconstructing the above objectives.Results The results show that the transverse resolution and signal-to-noise ratio of defocused region are improved compared with which of the B scan method. In the simulation, the resolution of the defocus area can be improved by about 26 times, and the signal-to-noise ratio can be improved by about 2.3 times after dynamic focusing. In the experiment, the resolution of remote point targets is improved 3-6 times after dynamic focusing reconstruction.Conclusion On the whole, we think that the algorithm based on spatial-temporal response and synthetic aperture focusing technology algorithm are more suitable for experimental conditions. This work has guiding significance for the design of acoustic focusing photoacoustic endoscopy imaging.]]> 2023/3/22 0:00:00 XIAO Xiao-Zhou,WU Hua-Lin,JIANG Jin-Sheng,CHEN Ze-Yu,WANG Bo and XIAO Jia-Ying 37true Objective As a powerful tool in correcting genomic point mutations, base editors (BEs) show a promising prospect for biotechnology development and therapeutic applications. While editing the target single-nucleotide variant (SNV), it’s primary to select competent BEs and design single guide RNA (sgRNA). Currently, although there are multiple sgRNA design tools, no tools are available for integrating the design of sgRNA with the assessment of the specificity of BEs.Methods 27 cytosine base editors (CBEs) and 12 adenine base editors (ABEs) were used to design base editing schemes. BE-Hive, a third-party tool, was provoked to predict the editing efficiency. The off-target profiles of editing schemes were evaluated by using a combination of multiple off-target prediction tools. Finally, all possible off-target editing products were calculated by considering both base editor types and off-target sites, and then ANNOVAR, a variant annotation tool, was called for functional analysis of off-target products.Results We propose a comprehensive tool, BE-dot, which enables the complete process from a given SNV to designing sgRNAs, predicting off-target profiles, and annotating off-target products’ functions. Besides providing precise correction schemes at DNA level, in order to expand the range of editable SNVs, BE-dot can perform synonymous corrections at protein level by degeneracy. When predicting off-target profiles of single base editing systems, BE-dot integrates multiple tools such as Cas-OFFinder, CALITAS, CFD, uCRISPR and BEdeepoff, which allows BE-dot to evaluate the specificity of single base editing systems more comprehensively and provide users with consultations about BEs and sgRNA selection. In addition, BE-dot can automatically analyze all possible editing products at off-target sites, and convert them into avinput format for functional annotation by ANNOVAR, avoiding the tedious manual annotation.Conclusion BE-dot designs editing schemes for applying base editing to correct or introduce SNVs, and comprehensively evaluates the editing scheme in terms of editing efficiency, off-target profile, and off-target functional impact.]]> 2023/2/22 0:00:00 WANG Ze-Lu,LIANG Jun-Bo and WANG Xiao-Yue 36true Objective The conductivity in bioelectromagnetic parameters is directly related to the functional information of the tissue, and precise reconstruction of biological tissue conductivity is of great significance in the fields of medical imaging technology and medical diagnosis. In this paper, the microwave-induced thermoacoustic tomography (MTAT) algorithm is improved to improve the reconstruction accuracy of tissue conductivity.Methods On the basis of utilizing the finite element discrete method to solve thermoacoustic wave equation and Helmholtz equation, an improved method of quantitative reconstruction of biological tissue conductivity based on regularized Newton iteration method (RNIM) is proposed in this paper.Results The effectiveness of the algorithm improvement was verified by numerical simulation and phantom experiments with different concentrations of NaCl solution. The results of the tissue phantom experiments showed that the relative error of the phantom conductivity quantitatively reconstructed by the regularized Newton method is significantly lower than that of the quantitative MTAT with fitting, for the cases with different target positions, sizes and contrasts. And the accuracy of the reconstruction is improved. Simultaneously, the RNIM method was used to reconstruct the conductivity of a single target with the same concentration at different positions with smaller variation in the mimic experiments, as well as the relative ratio of the reconstructed conductivity of multiple targets was closer to the actual one, which the experimental results verified the stability of the improved method.Conclusion The results show that the optimized algorithm reconstruct the conductivity of the tissue phantom more accurately and quantitatively, which is of great significance for the early screening and precise diagnosis of tumor localization and staging, to prevent the deterioration of the disease.]]> 2023/2/22 0:00:00 CHEN Yi,CHI Zi-Hui,WU Dan,LIU Yue,WEN Yan-Ting,LI Lun and JIANG Hua-Bei 35true Objective The exosome, a type of extracellular vesicle, is considered a kind of information carrier and biomarker and has a significant role in extracellular physiologic activities and disease progression. Research into the characteristics of exosomes is key to addressing numerous fundamental issues in pathologic processes. Exosomes are secreted by tumor cells into the tumor microenvironment through exocytosis. Exosome vesicles carry a large amount of genetic information related to the tumor cells from which they are derived. So exosome plays an important role in the tumor microenvironment, such as information transmission, immune regulation, promotion of tumor invasion and metastasis, and regulation of tumor response to drugs. At present,most exosomes research focuses on the bioinformatics exploration of protein expression, mRNA, lncRNA and other aspects of exosomes, and there is still a lot of space to explore the microscopic morphology and physical characteristics of exosomes. This study investigated the physical characteristics of plasma exosomes from patients with lymphoma through atomic force microscopy (AFM).Methods The exosome has been extracted from clinical cancer patients’ peripheral blood samples. The samples contain diffuse large B cell lymphoma and follicular lymphoma. At first, the electrostatic adsorption method has been utilized to fix the isolated exosomes onto the mica substrates, the discrete living exosomes have been scanned with AFM method. The multi-parameter exosome images at nano/micro scale can be obtained in situ.Results The multi-parameter mechanical properties of isolated living exosomes have been visualized and quantitatively measured. The significant fringe effect at the edge of the exosome has been revealed in the AFM adhesion image, which means more energy dissipation can be produced there. The Young’s modulus of plasma exosomes was different in patients with lymphoma from different pathological subtypes.Conclusion Plasma exosomes from patients with hematological tumors can be successfully extracted. Due to the convenient and less invasive characteristics of peripheral blood, plasma exosomes can be used as biomarkers for dynamic monitoring and analysis of tumor diagnosis and treatment, and the extracted exosomes can be captured by AFM probes through treatment and fixation. In this study, the morphological details and mechanical properties of exosomes at nano and micro scales were revealed. The physical properties of exosomes may be related to their biological properties.The multi-dimensional understanding of exosome performance opens up a new perspective for the future application and in-depth study of exosomes.]]> 2023/1/16 15:04:36 LI Xin-Xin,LIU Zhi-Hua,WANG Xin-Lei,WANG Wen-Xue and XING Xiao-Jing 34true Objective Implantable brain computer interface has been widely used in the treatment of neurological diseases, where the effectiveness of the treatment depends on the electrodes in contact with the neural tissue. Compared with the electrodes made of rigid materials, the carbon based microfiber electrodes have small scale, good biocompatibility and small tissue inflammatory reaction. It can reduce the foreign body reaction after implantation, improve the signal-to-noise ratio of nerve recording signals, and maintain stable electrode characteristics for a long time.Methods A modification method of flexible carbon nanotubes (CNTs) fiber electrode was designed in this paper. Poly(3,4-ethylenedioxythiophene) (PEDOT) films can be deposited on CNTs fiber electrode as microelectrode coating by electrochemical polymerization. In order to prove that the modified coating has good mechanical stability on the electrode surface, we treated the modified electrode with ultrasonic treatment. In addition, PEDOT films were deposited on ITO glass to evaluate the biocompatibility of PEDOT films.Results PEDOT coating deposited on the surface of CNTs fiber electrode in constant current mode reduced the electrochemical impedance of the electrode and improved the electrochemical performance of the electrode. The longer PEDOT deposition time, the more obvious the reduction of impedance. After ultrasonic treatment, the electrochemical impedance of the electrode did not change significantly, indicating that there was less peeling of PEDOT coating after ultrasonic treatment, which proved that the modified coating had good mechanical stability on the electrode surface. Finally, cell experiments show that PEDOT film has the same cell compatibility as ITO conductive glass.Conclusion PEDOT film can improve the stability of CNTs fiber electrode, and is expected to improve the service life and reliability of brain computer interface system. It has the prospect of application in long-term recording of neuroelectrical signals.]]> 2023/1/16 15:04:40 YANG Yu-Xi,GAO Zhong-Bao,CAO Zhen,LI Si-Wei,ZHANG Xiao,LIU Wei,ZHU Ying and ZHOU Jin 33true Objective Optically pumped magnetometer (OPM)-magnetoencephalography (MEG) is a rapidly developing new-generation brain function imaging technology compared to the traditional MEG. Due to the proximity of the detectors and the scalp, OPM-MEG offers higher signal intensity and, with its multiaxis detection capability, can detect signals in the “blind area” of traditional MEG. It provides a powerful tool to the research of brain function and clinical diagnosis. This paper aims to investigate the signal distribution differences of biaxial OPM-MEG when measuring true physiological responses and to compare its performance with traditional MEG.Methods In this study, ten healthy subjects were examined using a 9-channel biaxial OPM-MEG during an auditory task involving frequency following responses (FFR). FFR-related magnetic responses were acquired along both tangential (Y-axis) and radial (Z-axis) directions. We analyzed the OPM-MEG data features in different axial directions and different regions, including signal intensity and regional mean energy. Additionally, we compared the results with the data detected by traditional MEG.Results After processing 800 trials, the average signal energy in the Y-axis and Z-axis was found to be 0.971 0 and 0.767 3 respectively, with no statistical significance (P=0.438). However, a regional analysis revealed distinct signal distribution patterns in the left temporal area compared to the other two regions, which was statistically significant (P=0.049). Topographical mapping showed a clear left-sided lateralization, similar to SQUID-MEG results. PSD analysis and wavelet time-frequency analysis further supported these findings. In-depth analysis of peak-to-peak values from all sensors during the stimulus period (0-0.2 s) revealed that within-participant measurements showed consistency, whereas between-participant variability was considerable. This highlights the importance of considering individual differences in future studies, as they can significantly impact measurement outcomes. The analysis revealed that the biaxial OPM-MEG signals were stronger than traditional MEG signals. Furthermore, there were significant differences in signal distribution and intensity between the two axes. In most subjects, tangential signals were found to be significantly stronger than radial signals, which are generally difficult to capture using traditional MEG.Conclusion Our findings demonstrate the capability of biaxial OPM-MEG in capturing real physiological signals and show that it provides richer information compared to uniaxial measurement. This study suggests that traditional MEG may be missing critical brain activities in its “blind areas”, highlighting the need for optimizations in brain electrical activity models based on uniaxial (radial) MEG recordings. With its multi-axis recording capability, OPM-MEG holds great potential in brain science research and the diagnosis of neurological diseases, offering a more comprehensive and precise tool for understanding brain functions.]]> 2023/12/22 11:27:23 WANG Tian-Yu,ZHENG Yu,YANG Si-Jia,ZHANG Li-Wei and WANG Fan 32true Objective N⁶-methyladenosine (m⁶A) is the most common and abundant chemical modification in RNA and plays an important role in many biological processes. Several computational methods have been developed to predict m⁶A methylation sites. However, these methods lack robustness when targeting different species or different tissues. To improve the robustness of the prediction performance of m⁶A methylation sites in different tissues, this paper proposed a double-layer bidirectional gated recurrent unit (BiGRU) network model that combines reverse sequence information to extract higher-level features of the data.Methods Some representative mammalian tissue m⁶A methylation site datasets were selected as the training datasets. Based on a BiGRU, a double-layer BiGRU network was constructed by collocation of the model network, the model structure, the number of layers and the optimizer.Results The model was applied to predict m⁶A methylation sites in 11 human, mouse and rat tissues, and the prediction performance was compared with that of other methods using the same tissues. The results demonstrated that the average area under the receiver operating characteristic curve (AUC) predicted by the proposed model reached 93.72%, equaling that of the best prediction method at present. The values of accuracy (ACC), sensitivity (SN), specificity (SP) and Matthews correlation coefficient (MCC) were 90.07%, 90.30%, 89.84% and 80.17%, respectively, which were higher than those of the current methods for predicting m⁶A methylation sites.Conclusion Compared with that of existing research methods, the prediction accuracy of the double-layer BiGRU network was the highest for identifying m⁶A methylation sites in the 11 tissues, indicating that the method proposed in this study has an excellent generalizability.]]> 2023/12/22 11:27:28 LI Hui-Min,CHEN Peng-Hui,TANG Yi,XU Quan-Feng,HU Meng and WANG Yu 31true Objective Detection and quantification of RNA synthesis in cells is a widely used technique for monitoring cell viability, health, and metabolic rate.After exposure to environmental stimuli, both the internal reference gene and target gene would be degraded. As a result, it is imperative to consider the accurate capture of nascent RNA and the detection of transcriptional levels of RNA following environmental stimulation. This study aims to create a Click Chemistry method that utilizes its property to capture nascent RNA from total RNA that was stimulated by the environment.Methods The new RNA was labeled with 5-ethyluridine (5-EU) instead of uracil, and the azido-biotin medium ligand was connected to the magnetic sphere using a combination of “Click Chemistry” and magnetic bead screening. Then the new RNA was captured and the transcription rate of 16S rRNA was detected by fluorescence molecular beacon (M.B.) and quantitative reverse transcription PCR (qRT-PCR).Results The bacterial nascent RNA captured by “Click Chemistry” screening can be used as a reverse transcription template to form cDNA. Combined with the fluorescent molecular beacon M.B.1, the synthesis rate of rRNA at 37℃ is 1.2 times higher than that at 15℃. The 16S rRNA gene and cspI gene can be detected by fluorescent quantitative PCR,it was found that the measured relative gene expression changes were significantly enhanced at 25℃ and 16℃ when analyzed with nascent RNA rather than total RNA, enabling accurate detection of RNA transcription rates.Conclusion Compared to other article reported experimental methods that utilize screening magnetic columns, the technical scheme employed in this study is more suitable for bacteria, and the operation steps are simple and easy to implement, making it an effective RNA capture method for researchers.]]> 2024/9/19 20:43:47 LI Yuan-Yuan,WANG Yu-Ting,WU Zi-Chun,LI Hao-Xuan,FEI Ming-Yue,SUN Dong-Chang,GUALERZI O. Claudio,FABBRETTI Attilio,GIULIODORI Anna Maria,MA Hong-Xia and HE Cheng-Guang 30true Objective The distribution of water content in plant leaves is an important indicator for measuring plant physiology and biochemistry, and it is also an important basis for formulating drought resistance strategies in the field of agricultural science. Microwave imaging has high contrast and sensitivity in the distribution and variation of water content, while ultrasound imaging has high resolution. Based on this, this paper proposes a non-destructive microwave thermoacoustic imaging (TAI) technology that combines the advantages of microwave and ultrasound imaging, and uses this technology to carry out non-destructive testing research on the distribution of plant leaf water content, which is of great significance for achieving precise irrigation, developing water-saving agriculture, and improving water resource utilization.Methods This study constructs a two-dimensional transmissive TAI system with an excitation frequency of 3.0 GHz and a lateral resolution of 0.406 μm. Based on active heating technology (150°C hot air, 90 s), 3 sets of mandala leaf moisture loss processes were simulated, and their TAI images were quantitatively analyzed.Results The results showed that heating caused local moisture loss and reduced thermoacoustic signals, verifying the feasibility of non-destructive detection of plant leaf water content changes based on TAI, which achieves non-destructive detection of water content distribution in leaves of Datura, Crassocephalum crepidioides and Perilla. The results are consistent with magnetic resonance imaging (MRI).Conclusion This study contributes to achieve precise irrigation and provides technical support for studying the response characteristics of plants to the environment under normal and stress environments. Especially when combined with non-contact ultrasound detection technology, remote sensing of plant leaf water content can be achieved, which has more practical value.]]> 2024/8/15 12:35:51 XIE Shi-Meng,TANG Yong-Hui and HUANG Lin 29true Objective Rapid and accurate identification of body fluid traces at crime scenes is crucial for case investigation. Leveraging the speed and sensitivity of nucleic acid detection technology based on SHERLOCK, our research focuses on developing a peripheral blood SHERLOCK-HBA detection system to detect mRNA in forensic practice.Methods Short crRNA fragments targeting the blood-specific mRNA gene HBA were designed and screened, alongside RPA primers. Optimal RPA primers were selected based on specificity and amplification efficiency, leading to the establishment of the RPA system. The most efficient crRNA was chosen based on relative fluorescence units (RFU) generated by the Cas protein reaction, and the Cas protein reaction system was constructed to establish the SHERLOCK-HBA detection method. The RPA and Cas protein reaction systems in the SHERLOCK detection system were then individually optimized. A total of 79 samples of five body fluids were tested to evaluate the method’s ability to identify blood, with further verification through species-specific tests, sensitivity tests, mixed spots detection, aged samples, UV-irradiated samples, and actual casework samples.Results The SHERLOCK reaction system for the peripheral blood-specific marker HBA was successfully established and optimized, enabling detection within 30 min. The method demonstrated a detection limit of 0.001 ng total RNA, better than FOB strip method and comparable to RT-PCR capillary electrophoresis. The system could detect target body fluids in mixed samples and identify blood in samples stored at room temperature for three years and exposed to UV radiation for 32 h. Detection of 11 casework samples showed performance comparable to RT-PCR capillary electrophoresis.Conclusion This study presents a CRISPR/Cas-based SHERLOCK-HBA detection system capable of accurately, sensitively, and rapidly identifying blood samples. Introducing CRISPR/Cas technology to forensic body fluid identification represents a significant advancement in applying cutting-edge molecular biology techniques to forensic science.The method’s simplicity, shorter detection time, and independence from specialized equipment make it promising for rapid blood sample identification in forensic cases.]]> 2024/8/15 0:00:00 YAO Qian-Wei,HE Hong-Xia,HU Sheng,ZHAO Yi-Xia,LUO Yu,JI An-Quan and SUN Qi-Fan 28true Objective Inferring cancer driver genes, especially rare or sample-specific cancer driver genes, is crucial for precision oncology. Considering the high inter-tumor heterogeneity, a few recent methods attempt to reveal cancer driver genes at the individual level. However, most of these methods generally integrate multi-omics data into a single biomolecular network (e.g., gene regulatory network or protein-protein interaction network) to identify cancer driver genes, which results in missing important interactions highlighted in different networks. Thus, the development of a multiplex network method is imperative in order to integrate the interactions of different biomolecular networks and facilitate the identification of cancer driver genes.Methods A multiplex network control method called Personalized cancer Driver Genes with Multiplex biomolecular Networks (PDGMN) was proposed. Firstly, the sample-specific multiplex network, which contains protein-protein interaction layer and gene-gene association layer, was constructed based on gene expression data. Subsequently, somatic mutation data was integrated to weight the nodes in the sample-specific multiplex network. Finally, a weighted minimum vertex cover set identification algorithm was designed to find the optimal set of driver nodes, facilitating the identification of personalized cancer driver genes.Results The results derived from three TCGA cancer datasets indicate that PDGMN outperforms other existing methods in identifying personalized cancer driver genes, and it can effectively identify the rare driver genes in individual patients. Particularly, the experimental results indicate that PDGMN can capture the unique characteristics of different biomolecular networks to improve cancer driver gene identification.Conclusion PDGMN can effectively identify personalized cancer driver genes and broaden our understanding of cancer driver gene identification from a multiplex network perspective. The source code and datasets used in this work are available at https://github.com/NWPU-903PR/PDGMN.]]> 2024/7/19 0:00:00 ZHANG Tong,ZHANG Shao-Wu,LI Yan and XIE Ming-Yu 27true Objective The chemical exchange saturation transfer (CEST) technique has become a valuable tool in diagnosing metabolic changes associated with cerebral and systemic diseases, leveraging the calculation of compounds with exchangeable protons in proximity to water molecules. Specifically, the amide proton transfer (APT) CEST technique has shown promise in diagnosing cerebral strokes and tumors by comparing altered endogenous proteins or peptides with normal tissues. Reduced field of view (rFOV) imaging technology has been widely used in the diagnosis of small organ lesions in the body. In this study, we aim to apply the rFOV imaging to identify CEST signals in the rectum, investigating the potential utility of rFOV technique in clinical diagnosis of rectal diseases and providing metabolic insights for chemoradiotherapy.Methods MRI images of eleven healthy volunteers were acquired using transverse Full_FOV and rFOV CEST imaging on a 3T scanner. The resolution was set at 2.5×2.5× 6 mm3 and 1.5×1.5×6 mm3 for Full_FOV or the rFOV method. Saturation powers of 0.7 μT and 2 μT were applied. For the 2 μT saturation, MTRasym at ±3.5 ppm was employed, while for 0.7 μT saturation, Lorentzian difference was used for CEST quantification of the contrast maps and curves.Results The rFOV method has the advantage of halving the scan time while maintaining the same contrast as the Full_FOV method. When compared to Full_FOV methods, rFOV methods exhibited nearly identical Z_spec and very similar MTRasym curves. Additionally, rFOV with a 1.5 mm×1.5 mm in-plane resolution could be achieved in approximately 3 min. rFOV method displayed better structural details for the entire rectum, including CEST contrast maps and quantitative curves.Conclusion CEST MRI proves valuable in diagnosing rectal diseases, and employing the rFOV technique could provide higher spatial and temporal resolution. CEST MRI should be the preferred choice for offering improved diagnostic capabilities with its potential for rectal disease diagnosis.]]> 2024/7/30 17:10:45 CHAI Xu-Bin,WANG Yi,HE Zi-Jun,LIU Ai-Hua and XUE Rong 26true Objective Cellular temperature imaging can assist scientists in studying and comprehending the temperature distribution within cells, revealing critical information about cellular metabolism and biochemical processes. Currently, cell temperature imaging techniques based on fluorescent temperature probes suffer from limitations such as low temperature resolution and a limited measurement range. This paper aims to develop a single-cell temperature imaging and real-time monitoring technique by leveraging the temperature-dependent properties of single-molecule quantum coherence processes.Methods Using femtosecond pulse lasers, we prepare delayed and phase-adjustable pairs of femtosecond pulses. These modulated pulse pairs excite fluorescent single molecules labeled within cells through a microscopic system, followed by the collection and recording of the arrival time of each fluorescent photon. By defining the quantum coherence visibility (V) of single molecules in relation to the surrounding environmental temperature, a correspondence between V and environmental temperature is established. By modulating and demodulating the arrival times of fluorescent photons, we obtain the local temperature of single molecules. Combined with scanning imaging, we finally achieve temperature imaging and real-time detection of cells.Results This method achieves high precision (temperature resolution <0.1°C) and a wide temperature range (10-50°C) for temperature imaging and measurement, and it enables the observation of temperature changes related to individual cell metabolism.Conclusion This research contributes to a deeper understanding of cellular metabolism, protein function, and disease mechanisms, providing a valuable tool for biomedical research.]]> 2024/5/21 20:01:42 ZHOU Hai-Tao, QIN Cheng-Bing, XIAO Lian-Tuan, WU Zhi-Fang, LI Si-Jin 25true Objective Based on fluorescence lifetime imaging technology, a novel method for viscosity detection is proposed and the capability of different weighting of fluorescence lifetimes in distinguishing the viscosity of glycerol-water mixtures is evaluated, aiming to enhance the accuracy and reliability of viscosity differentiation.Methods This approach incorporates the principles of electronic weighting, introducing both amplitude-weighted average fluorescence lifetime (τ_m) and intensity-weighted average fluorescence lifetime (τ_i). Viscosity changes in glycerol-water mixtures are detected through τ_m and τ_i. τ_m Reflects the relationship between fluorescence signal amplitude and time, while τ_i focuses on the time-varying characteristics of fluorescence signal intensity.Results The results of both τ_m and τ_i mutually corroborate each other, not only enhancing the reliability in detecting viscosity changes in glycerol-water mixtures but also revealing their unique roles in the detection process. Although τ_m plays a crucial role in capturing changes in fluorescence signal amplitude, τ_i exhibits higher accuracy in viscosity detection when considering the time-varying characteristics of fluorescence signal intensity. It is particularly noteworthy that, due to τ_i’s greater sensitivity, microenvironment viscosity detection can be directly analyzed using τ_i. This provides a more convenient approach for real-time, highly sensitive microfluidic viscosity monitoring. Therefore, through the comprehensive utilization of τ_m and τ_i, a more thorough and accurate understanding of the viscosity information in glycerol-water mixtures can be obtained, and specific parameters can be selected for in-depth analysis based on specific needs.Conclusion The combination of amplitude weighting and intensity weighting allows for a more sensitive identification of subtle changes in viscosity under different conditions. The innovation of this method lies in its simultaneous consideration of multiple parameters, enhancing sensitivity and distinguishability to variations in viscosity. Therefore, this weighted-dependent fluorescence lifetime imaging technique not only introduces a novel approach for viscosity detection in glycerol-water mixtures but also provides a powerful analytical tool for various fields, including microfluidics, rheology, and research on novel functional materials.]]> 2024/5/21 20:01:49 LUO Teng,ZHAO Yi-Hua,LU Yuan,YAN Wei and QU Jun-Le 24true Objective This study aimed to develop a novel method for encapsulating oocytes in sodium alginate hydrogel using microfluidics, then to vitrify these encapsulated oocytes in a single-step process with low concentrations of cryoprotectants.Methods We utilized a flow-focusing microfluidic chip to generate sodium alginate hydrogel microspheres. The influence of various parameters, including throat structure, cross-linking method, sodium alginate concentrations, and flow rate ratios on the stability diameter, and coefficient of variation of microspheres were examined. To further investigate the cold-resistance of these microspheres, we used cryomicroscopy to observe changes in volume and morphology of microspheres during cooling and warming processes. We used microfluidic chip to encapsulate oocytes in sodium alginate hydrogel microspheres, the empty rate of microspheres and loss rate of oocytes were determined. After releasing from microspheres and parthenogenetic activation with cytochalasin B and strontium chloride, the survival, cleavage and blastocyst rates were evaluated during in vitro maturation. Finally, oocytes encapsulated in sodium alginate microspheres were vitrified with low concentrations of cryoprotectants. We compared the survival and development capability of the oocytes with the Cryotop method.Results When the throat of the microfluidic chip measures 300 μm in length and 120 μm in width, microspheres can be uniformly formed at the throat of the chip. Sodium alginate generates microspheres with a wide size distribution when cross-linking outside the chip, while internal cross-linking within the chip results in more uniform microspheres. The stability of microsphere formation is significantly improved with the use of a three-channel internal cross-linking chip. At a flow rate of 2 μl/min and with 1% sodium alginate, the microfluidic chip can consistently and uniformly produce microspheres. Under flow rate ratios of 10, 15, and 20, the average microsphere diameters are 262.71 μm, 193.63 μm, and 156.63 μm, respectively. The sodium alginate hydrogel microspheres maintained their volume and structural integrity during the cooling and warming processes. Using a three-channel internal cross-linking microfluidic chip to encapsulate oocytes, at a flow rate ratio of 10, the empty rate is 32.28%, and the cell loss rate is 11.09%. After encapsulation and subsequent release, the oocyte survival rate (96.99%), cleavage rate (88.71%), and blastocyst formation rate (26.29%) showed no significant differences compared to the fresh group. After the microspheres were vitrified using a low concentration of cryoprotectant (10% DMSO+10% ehylene glycol (EG)+0.5 mol/L trehalose), the survival rate, cleavage rate, and blastocyst rate were 92.48%, 70.80%, and 20.42%, respectively. No significant difference was observed when compared to the Cryotop method using a higher concentration of cryoprotectant solution (15% DMSO+15% EG+0.5 mol/L trehalose).Conclusion We designed and fabricated a microfluidic system with three-channel internal cross-linking chips used for oocyte vitrification preservation. The microfluidic system can generate oocytes-loaded sodium alginate hydrogel microspheres with uniform size, low empty rate, and good cold-resistance. The method successfully reduced the concentration of cryoprotectants in a single-step vitrification process, the developmental capability of oocytes during in vitro maturation were comparable with Cryotop method. Unlike the Cryotop method, the oocytes encapsulated in hydrogel does not come into contact with liquid nitrogen, eliminating the risk of cross-contamination. This study provides a novel approach to oocyte vitrification.]]> 2024/4/19 9:42:45 ZHANG Hui,ZHANG Yu-Qi,HU Jian-Lin and ZHOU Xin-Li 23true Objective Body fluid stains left at crime scenes are frequently trace amounts, while the identification of body fluids through real time fluorogenic quantitative technique often necessitates the repeated detection within the limited sample, as multiple miRNA markers are the basis for the identification. Based on the goal of both the throughput and efficiency improvement of miRNA analysis in trace samples, a duplex real time fluorogenic quantitative PCR assay system was designed to accurately quantify two miRNAs simultaneously, and the system should be further verified by actual sample for the body fluid identification.Methods The duplex real time fluorogenic quantitative PCR system of miR-451a to miR-21-5p was established with specially designed primers and probes, and the concentrations of the primers and probes were both optimized. The specificity, sensitivity and reproducibility of the system were validated, while its capability for body fluid identification was assessed using the miR-451a to miR-21-5p ratio.Results The optimized assay system exhibited excellent specificity and repeatability, with coefficients of variation consistently below 8% for both intra- and inter-batch variability. The amplification efficiency of miR-451a and miR-21-5p reached 71.77% and 74.81%, respectively, with high and relatively consistent results. By utilizing this duplex real time fluorogenic quantitative PCR assay system, a total of 58 body fluid samples were analyzed, exhibiting a discrimination rate of 100% between blood and non-blood samples, as well as between peripheral blood and menstrual blood samples. Moreover, the results, obtained from single real time fluorogenic quantitative PCR assay system and duplex real time fluorogenic quantitative PCR assay system, showed no statistically significant difference with randomly selected blood samples (n=20). Compared to previous single real time fluorogenic quantitative PCR assay system, the sensitivity of duplex real time fluorogenic quantitative PCR assay system exhibited remarkable improvement. A minimum input of only 0.1 ng total RNA was sufficient for accurate detection of peripheral blood and menstrual blood samples, while saliva, semen, and vaginal secretion required only 1 ng total RNA for precise identification purposes. Additionally, the duplex real time fluorogenic quantitative PCR assay system successfully differentiated between different types of body fluids in simulated samples under natural outdoor conditions.Conclusion The duplex real time fluorogenic quantitative PCR assay system effectively reduced both the time and material costs by half compared to the single system, especially suitable for the examination of body fluid stains left at crime scenes, solving the contradiction between the trace amount and the multiple sample volumes demand of repeated real time fluorogenic quantitative PCR. The duplex real time fluorogenic quantitative PCR assay successfully distinguished blood and other body fluid, as well as peripheral blood and menstrual blood samples, which maintains an equivalent capability for body fluid identification with half sample, time and reagent consumption. This system provides an efficient tool for identifying suspicious body fluids, as well as a foundation for more multiplexed real time fluorogenic quantitative PCR assay system research.]]> 2024/3/20 17:40:01 HU Shu-Xiao,CHEN Hui-Xiang,HU Sheng,ZHAO Yi-Xia,JI An-Quan,LI Yang,LIAN Jie and SUN Qi-Fan 22true Objective Molecular docking plays a critical role in predicting binding modes and affinity between molecules, serving as a pivotal method in structural biology and computer-aided drug design research. Our research team has recently developed a novel template-based docking method called FitDock, which outperforms commonly used molecular docking methods in terms of accuracy and speed, particularly when approximate protein-ligand templates are available. To enhance the accessibility of the FitDock method and promote its broader application in the field of molecular simulation, the development of a graphical software tool is imperative.Methods Utilizing Python-based graphical programming, we have created FitDockApp, a plugin software for the molecular visualization software PyMOL.Results FitDockApp enables template-based molecular docking and ligand structure alignment through an interactive graphical interface, providing real-time visualization of predicted three-dimensional structures. It also offers the convenience of uploading docking files to a laboratory server to obtain the optimal template. Additionally, FitDockApp includes batch docking functionality.Conclusion FitDockApp simplifies the docking process through its user-friendly interface and provides robust functionality to assist researchers in obtaining precise docking results. FitDockApp is a free software compatible with both Windows and Linux systems and can be downloaded from http://cao.labshare.cn/fitdock/.]]> 2024/3/20 17:40:02 WANG You-Jun,YANG Yu-Chan,LIU Yang,XIAO Zhi-Xiong and CAO Yang 21true Objective The advent of atomic force microscope (AFM) provides a powerful tool for the studies of life sciences. Particularly, AFM-based indentation assay has become an important method for the detection of cellular mechanics, yielding numerous novel insights into the physiological and pathological activities from the single-cell level and considerably complementing traditional biochemical ensemble-averaged assays. However, current AFM indentation technology is mainly dependent on manual operation with low efficiency, seriously restricting its practical applications in the field of life sciences. Here, a method based on the combination of deep learning image recognition and AFM is developed for precisely and efficiently detecting the mechanical properties of single isolated cells and clustered cells.Methods The YOLO deep learning algorithm was used to recognize the central region of the cell in the optical image, the dual UNet neural network with an embedded vision transformer (ViT) module was used to recognize the peripheral regions of cell, and the template matching algorithm was used to recognize the tip of spherical probe. Based on the automatic determination of the positional relationships between the microsphere tip and the different parts of cell, the AFM tip was accurately moved to the central and peripheral regions of the target cell for rapid measurements of cell mechanical properties. Two types of cells, including HEK 293 cell (human embryonic kidney cell) and HGC-27 cell (human undifferentiated gastric cancer cell), were used for the experiments. The Hertz model was applied to analyze the force curves obtained on cells to obtain cellular Young’s modulus.Results AFM probe can be precisely moved to the different parts (central areas and peripheral areas) of cells to perform mechanical measurements under the guidance of deep learning-based optical image automatic recognition. The experimental results show that the proposed method is not only suitable for single isolated cells, but also suitable for clustered cells.Conclusion The research demonstrates the great potential of deep learning image recognition to aid AFM in the precise and efficient detection of cellular mechanical properties mechanics, and combining deep learning-based image recognition with AFM will benefit the development of high-throughput AFM-based methodology to measure the mechanical properties of cells.]]> 2024/2/22 16:33:48 Lü Xiao-Long and LI Mi 20true Objective Hair is an essential skin appendage, primarily composed of keratins and keratin-associated proteins. The protein composition and proportion of hair samples vary among different races and sexes. Currently, there is a lack of efficient methods to extract hair proteins. This study aims to explore the application of quantitative hair proteomics in distinguishing individual hair characteristics.Methods Based on the exploration of sample processing and lysis buffer using three hair samples, we developed a stable and efficient hair protein extraction method, named PLEE (PTM lab for protein extraction from hair with high efficiency). We used the PLEE method to extract seven human hair samples and performed proteomic experiments on them using in-gel digestion method to produce data for analyzing hair protein composition and proportion among individuals.Results A total of 274 proteins were identified, among which 107 proteins were commonly present, and the number of non-common proteins ranged from 57-119, with some samples having unique identification proteins. Using the 107 commonly identified proteins for quantitative protein fractionation analysis, various samples were distinguished by clustering and principal component analysis, and technical repeated samples were merged, indicating the stability of the process. In addition, 10 key proteins (KRT33A, KRTAP9-6, KRT83, KRTAP7-1, KRT32, BLMH, KRT38, KRTAP11-1, NPAS1, KRTAP4-3) with large differences between individuals and stable protein identification within the same individual were screened.Conclusion The protein composition of hair varies among different individuals, and the 10 selected proteins are expected to be key proteins for distinguishing individual hair characteristics and have significant potential applications in individual identification and criminal investigation.]]> 2024/1/19 11:51:33 WU Xiao-Lin,ZHANG Tao,XU Ping,ZHANG Ya-Li and ZHANG Zhen-Peng 19true Objective Dust has steadily emerged as a frontier research in the field of forensic science because it is a material evidence with significant features and application potential that carries rich environmental DNA information. However, as a crucial foundational step in forensic applications, the collection and DNA extraction research of dust on object surfaces from the perspective of practical applications in forensic science are still in urgent need of development.Methods Dust was collected from object surfaces using a Copan Liquid Amies Elution Swab. DNA was extracted separately from the swab head, sediment, and supernatant within the sample collection tube to evaluate DNA content, thereby determining which components within the tube should be processed and lysed. Dust samples were collected according to five different sampling areas (25-400 cm2) and the DNA concentration was measured to determine the optimal sampling area. The extraction efficiency of three commercial DNA extraction kits for dust samples was compared. The size of the DNA fragments extracted from the dust was analyzed, as well as the presence of human DNA. Additionally, 16S rDNA amplicon sequencing was used to analyze the bacterial information in dust DNA from object surfaces. This process aimed to establish a quality control method for dust DNA extraction. Regarding the critical step of cell lysis in DNA extraction, the quantity of DNA extracted was compared and evaluated under different cell lysis methods and varying vortexing times. This was done to establish an appropriate cell lysis method for dust DNA extraction.Results The sediment and swab head in the dust sampling tube are the primary sources of DNA, and both should be included in subsequent extraction processes. The sampling area of dust is positively correlated with dust DNA concentration, and it is recommended that the sampling area be larger than 5×5 cm2. Using the DNeasy PowerSoil Pro kit can yield a higher amount of DNA. Additionally, there were no significant differences in the sizes of DNA fragments extracted by the three different DNA extraction kits. No human DNA was detected in the DNA extracted from the dust samples, while bacterial DNA was present in the dust from object surfaces. Furthermore, there were differences in microbial species composition between different sampling points. Additionally, using a biological sample homogenizer to grind and lyse for 4 min (2 min× 2 times) resulted in the highest concentration of dust DNA.Conclusion The extraction of dust DNA is influenced by the sampling area, extraction kits, and lysis methods. It is crucial to establish a comprehensive and suitable dust DNA extraction scheme. This not only lays the foundation for researching and extracting environmental DNA data from dust, but also provides a methodological reference for forensic case work involving environmental samples.]]> 2024/6/12 0:00:00 YANG Qi,PENG Jia-Jin,WANG Le,LU Qi,MEI Hong-Cheng,GE Wen-Dong,ZHANG Tao,JI An-Quan,YE Jian and KANG Ke-Lai 18true Objective The detection of RNA single nucleotide polymorphism (SNP) is of great importance due to their association with protein expression related to various diseases and drug responses. At present, splintR ligase-assisted methods are important approaches for RNA direct detection, but its specificity will be limited when the fidelity of ligases is not ideal. The aim of this study was to create a method to improve the specificity of splintR ligase for RNA detection.Methods In this study, a dual-competitive-padlock-probe (DCPLP) assay without the need for additional enzymes or reactions is proposed to improve specificity of splintR ligase ligation. To verify the method, we employed dual competitive padlock probe-mediated rolling circle amplification (DCPLP-RCA) to genotype the CYP2C9 gene.Results The specificity was well improved through the competition and strand displacement of dual padlock probe, with an 83.26% reduction in nonspecific signal. By detecting synthetic RNA samples, the method demonstrated a dynamic detection range of 10 pmol/L-1 nmol/L. Furthermore, clinical samples were applied to the method to evaluate its performance, and the genotyping results were consistent with those obtained using the qPCR method.Conclusion This study has successfully established a highly specific direct RNA SNP detection method, and provided a novel avenue for accurate identification of various types of RNAs.]]> 2024/11/22 0:00:00 ZHANG Qin-Qin,LI Jin-Ze,ZHANG Wei,LI Chuan-Yu,ZHANG Zhi-Qi,YAO Jia,DU Hong,ZHOU Lian-Qun and GUO Zhen 17true Objective Glutathione (γ-glutamyl-L-cysteinylglycine, GSH) is the most abundant non-protein compound containing sulfhydryl (―SH) groups in cells. It serves as a source of reducing equivalents, effectively neutralizing harmful reactive substances, and playing a crucial role in maintaining cellular redox balance. Therefore, sensitive detection and accurate measurement of GSH levels in tissues are of great importance. In this work, we presents a novel method for GSH detection utilizing electron paramagnetic resonance (EPR) spectroscopy.Methods Initially, ABTS (2,2"-azino-bis(3-ethylbenzothiazoline-6-sulfonate acid)) solution was mixed with K₂S₂O₈ solution and reacted in the dark for 12 to 16 h to prepare ABTS·⁺ solution, which was then quantified using UV-Vis spectroscopy. Subsequently, the concentration of glutathione (GSH) was determined based on the changes in the EPR signal of ABTS·⁺. On this basis, the optimal reaction time and temperature were explored to establish a standard equation correlating the EPR signal intensity of ABTS·⁺ with GSH concentration. Finally, the derived standard curve was employed to quantitatively analyze the GSH concentration in whole blood from C57BL/6J mice, and the results were compared with those reported in the literature to verify the accuracy of the method.Results The experimental results demonstrate that this method has a linear detection range from 50 nmol/L to 15 μmol/L for GSH, spanning two orders of magnitude, with a limit of detection (LOD) at 0.50 nmol/L. The measured GSH content in mouse whole blood is (10 660±706) nmol/g Hb, which agrees with the value of (11 200±237) nmol/g Hb as previously reported. Furthermore, a similar method was developed for detection of glutathione disulfide (GSSG) at higher reaction temperature.Conclusion This article presents a novel assay for the rapid detection of GSH using the intensity of EPR signal from ABTS·⁺ as indicator. This method demonstrates enhanced detection sensitivity and a broader linear range compared to conventional colorimetric methods. Furthermore, we have extended the application of this method to detect GSH content in blood samples efficiently and accurately, offering valuable information for assessing tissue redox balance, thus holding significant potentials.]]> 2024/11/22 12:24:13 WANG Zhi-Wen,KUANG Jian,LIU Ao-Kun,WEI Ruo-Tong,YU Lu and TIAN Chang-Lin 16true Objective This study proposes a novel single-cell protein localization method based on a class perception graph convolutional network (CP-GCN) to overcome several critical challenges in protein microscopic image analysis, including the scarcity of cell-level annotations, inadequate feature extraction, and the difficulty in achieving precise protein localization within individual cells. The methodology involves multiple innovative components designed to enhance both feature extraction and localization accuracy.Methods First, a class perception module (CPM) is developed to effectively capture and distinguish semantic features across different subcellular categories, enabling more discriminative feature representation. Building upon this, the CP-GCN network is designed to explore global features of subcellular proteins in multicellular environments. This network incorporates a category feature-aware module to extract protein semantic features aligned with label dimensions and establishes a subcellular relationship mining module to model correlations between different subcellular structures. By doing so, it generates co-occurrence embedding features that encode spatial and contextual relationships among subcellular locations, thereby improving feature representation. To further refine localization, a multi-scale feature analysis approach is employed using the K-means clustering algorithm, which classifies multi-scale features within each subcellular category and generates multi-cell class activation maps (CAMs). These CAMs highlight discriminative regions associated with specific subcellular locations, facilitating more accurate protein localization. Additionally, a pseudo-label generation strategy is introduced to address the lack of annotated single-cell data. This strategy segments multicellular images into single-cell images and assigns reliable pseudo-labels based on the CAM-predicted regions, ensuring high-quality training data for single-cell analysis. Under a transfer learning framework, the model is trained to achieve precise single-cell-level protein localization, leveraging both the extracted features and pseudo-labels for robust performance.Results Experimental validation on multiple single-cell test datasets demonstrates that the proposed method significantly outperforms existing approaches in terms of robustness and localization accuracy. Specifically, on the Kaggle 2021 dataset, the method achieves superior mean average precision (mAP) metrics across 18 subcellular categories, highlighting its effectiveness in diverse protein localization tasks. Visualization of the generated CAM results further confirms the model’s capability to accurately localize subcellular proteins within individual cells, even in complex multicellular environments.Conclusion The integration of the CP-GCN network with a pseudo-labeling strategy enables the proposed method to effectively capture heterogeneous cellular features in protein images and achieve precise single-cell protein localization. This advancement not only addresses key limitations in current protein image analysis but also provides a scalable and accurate solution for subcellular protein studies, with potential applications in biomedical research and diagnostic imaging. The success of this method underscores the importance of combining advanced deep learning architectures with innovative training strategies to overcome data scarcity and improve localization performance in biological image analysis. Future work could explore the extension of this framework to other types of microscopic imaging and its application in large-scale protein interaction studies.]]> 2025/6/23 0:00:00 TANG Hao-Yang,YAO Xin-Yue,WANG Meng-Meng and YANG Si-Cong 15true Objective Transfer RNA-derived fragments (tRFs) are a recently characterized and rapidly expanding class of small non-coding RNAs, typically ranging from 13 to 50 nucleotides in length. They are derived from mature or precursor tRNA molecules through specific cleavage events and have been implicated in a wide range of cellular processes. Increasing evidence indicates that tRFs play important regulatory roles in gene expression, primarily by interacting with target messenger RNAs (mRNAs) to induce transcript degradation, in a manner partially analogous to microRNAs (miRNAs). However, despite their emerging biological relevance and potential roles in disease mechanisms, there remains a significant lack of computational tools capable of systematically predicting the interaction landscape between tRFs and their target mRNAs. Existing databases often rely on limited interaction features and lack the flexibility to accommodate novel or user-defined tRF sequences. The primary goal of this study was to develop a machine learning based prediction algorithm that enables high-throughput, accurate identification of tRF:mRNA binding events, thereby facilitating the functional analysis of tRF regulatory networks.Methods We began by assembling a manually curated dataset of 38 687 experimentally verified tRF:mRNA interaction pairs and extracting seven biologically informed features for each pair: (1) AU content of the binding site, (2) site pairing status, (3) binding region location, (4) number of binding sites per mRNA, (5) length of the longest consecutive complementary stretch, (6) total binding region length, and (7) seed sequence complementarity. Using this dataset and feature set, we trained 4 distinct machine learning classifiers—logistic regression, random forest, decision tree, and a multilayer perceptron (MLP)—to compare their ability to discriminate true interactions from non-interactions. Each model’s performance was evaluated using overall accuracy, receiver operating characteristic (ROC) curves, and the corresponding area under the ROC curve (AUC). The MLP consistently achieved the highest AUC among the four, and was therefore selected as the backbone of our prediction framework, which we named tRF Prospect. For biological validation, we retrieved 3 high-throughput RNA-seq datasets from the gene expression omnibus (GEO) in which individual tRFs were overexpressed: AS-tDR-007333 (GSE184690), tRF-3004b (GSE197091), and tRF-20-S998LO9D (GSE208381). Differential expression analysis of each dataset identified genes downregulated upon tRF overexpression, which we designated as putative targets. We then compared the predictions generated by tRF Prospect against those from three established tools—tRFTar, tRForest, and tRFTarget—by quantifying the number of predicted targets for each tRF and assessing concordance with the experimentally derived gene sets.Results The proposed algorithm achieved high predictive accuracy, with an AUC of 0.934. Functional validation was conducted using transcriptome-wide RNA-seq datasets from cells overexpressing specific tRFs, confirming the model’s ability to accurately predict biologically relevant downregulation of mRNA targets. When benchmarked against established tools such as tRFTar, tRForest, and tRFTarget, tRF Prospect consistently demonstrated superior performance, both in terms of predictive precision and sensitivity, as well as in identifying a higher number of true-positive interactions. Moreover, unlike static databases that are limited to precomputed results, tRF Prospect supports real-time prediction for any user-defined tRF sequence, enhancing its applicability in exploratory and hypothesis-driven research.Conclusion This study introduces tRF Prospect as a powerful and flexible computational tool for investigating tRF:mRNA interactions. By leveraging the predictive strength of deep learning and incorporating a broad spectrum of interaction-relevant features, it addresses key limitations of existing platforms. Specifically, tRF Prospect: (1) expands the range of detectable tRF and target types; (2) improves prediction accuracy through multilayer perceptron model; and (3) allows for dynamic, user-driven analysis beyond database constraints. Although the current version emphasizes miRNA-like repression mechanisms and faces challenges in accurately capturing 5"UTR-associated binding events, it nonetheless provides a critical foundation for future studies aiming to unravel the complex roles of tRFs in gene regulation, cellular function, and disease pathogenesis.]]> 2025/7/14 10:25:13 REN Dai-Xi,YI Jian-Yong,MO Yong-Zhen,YANG Mei,XIONG Wei,ZENG Zhao-Yang and SHI Lei 14true Objective Gliomas in the motor functional area can damage the corticospinal tract (CST), leading to motor dysfunction. Currently, there is a lack of unified methods for evaluating the extent of CST damage, especially in patients with high surgical risk where the minimum distance from the lesion to the CST is less than 10 mm. This study aims to further clarify the classification method and clinical significance of CST morphological changes in these patients.Methods This retrospective study analyzed 109 high-risk functional area glioma patients who underwent neurosurgical treatment with preoperative diffusion tensor imaging (DTI) imaging and intraoperative neurostimulation guidance between 2014 and 2024. All patients had a lesion-to-tract distance (LTD) of less than 10 mm between the CST and the lesion. Preoperative DTI evaluation of CST involvement-induced morphological changes were reviewed. Patients were divided into 3 groups: 17 cases (15.6%) with symmetric CST morphology compared to the healthy side (CST symmetry), 48 cases (44.0%) with significant CST morphology changes compared to the healthy side (CST deformation), and 44 cases (40.4%) with CST overlap with the tumor (CST overlap). Then we classified patients according to preoperative assessment of tumor-induced morphological changes, and analyze postoperative motor function for each category.Results Postoperative pathology showed a significantly higher proportion of high-grade gliomas (HGG) in the CST overlap group compared to the other two groups (P=0.001). Logistic regression analysis showed that CST overlap was a predictor of HGG (P=0.000). The rate of total tumor resection in the CST deformation group and overlap group was lower than in the CST symmetric group (P=0.008). There was a total of 41 postoperative hemiplegic patients, with 4 cases (23.5%) in the CST symmetric group, 11 cases (22.9%) in the CST deformation group, and 26 cases (59.1%) in the CST overlap group. CST overlap with the tumor predicted postoperative hemiplegia (P=0.016). Two-way ANOVA analysis of the affected/healthy side and CST morphology groups showed significant main effects of CST grouping and healthy-affected side (P=0.017 and P=0.010), with no significant interaction (P=0.31). The fractional anisotropy (FA) value in the CST overlap group and the affected side was lower. A decrease in the FA value on the affected side predicted postoperative hemiplegia (sensitivity 69.2%, specificity 71.9%).Conclusion We have established a method to predict postoperative hemiplegia in high-risk motor functional area glioma patients based on preoperative CST morphological changes. CST overlap leads to a decrease in CST FA values. This method can be used for precise patient management and aid in accurate preoperative surgical planning.]]> 2024/12/31 11:51:55 MA Qiang,YU Song-Lin,ZHAO Chu-Yue,WANG Xi-Jie,LIN Song,ZUO Zhen-Tao and YU Tao 13true Objective Molecular property prediction plays a crucial role in drug development, especially in virtual screening and compound optimization. The advancement of artificial intelligence (AI) technologies has led to the emergence of numerous deep learning-based methods, which have demonstrated significant potential in improving molecular property prediction. Nonetheless, acquiring labeled molecular data can be both costly and time-consuming. The scarcity of labeled data poses a substantial challenge for supervised machine learning models to effectively generalize across the vast chemical space. In order to overcome the above limitations, in this work, we proposed a novel Bert and GCN-based multimodal fusion method (called BGMF) to predict molecular property.Methods BGMF can extract comprehensive molecular representation from atomic sequences, molecular fingerprint sequences, and molecular graph data and combine them through pre-training and fine-tuning. Specifically, our method consists of the following three main parts. (1) Molecular feature extraction; (2) Bert-GCN based pre-training; (3) fine-tuning. During molecular feature extraction, the Morgan algorithm is employed to generate the molecular fingerprints, transforming input SMILES strings of drugs into molecular fingerprint sentences. Simultaneously, atom sentences are created based on the atom indices within the molecule, Consequently, drug molecule are represented as both molecular fingerprint sentences and atom sentences. In the pre-training section, BGMF utilizes a self-supervised learning strategy, specifically masked molecular fingerprint and masked atom recovery, on a large dataset of unlabeled data using the Bert model. Here, molecular graph data is incorporated by merging graph convolutional neural networks with the Bert model, effectively combining the global “word” features of drug molecules with the local topological features of molecular graphs. We have also developed a dual decoder for atomic and molecular fingerprints to amplify molecular feature expression. Finally, in the fine-tuning stage, the addition of a pooling layer and task-specific fully connected neural networks allows the pre-trained module to be applied to a variety of downstream tasks for molecular property prediction.Results To validate the effectiveness of our BGMF, we conduct several experiments on 43 molecular attribute prediction tasks across 5 datasets. In comparison with other recent state-of-the-art methods, our BGMF achieves the best results in terms of area under the ROC curve (AUC). We also verified the generalization performance of the BGMF model by constructing independent test dataset, showing that the BGMF model has the best generalization performance. Additionally, we conduct the ablation studies to demonstrate the effect of atomic sequence, molecular fingerprint sequence, GCN based molecular graph module, and pre-training module on the overall performance of the model.Conclusion In this paper, we propose a novel method for drug molecular attribute prediction named BGMF which integrating the molecular graph data into tasks of molecular fingerprint recovery and masked atom recovery by combining graph convolutional neural network with the Bert model. The molecular fingerprint representations generated by BGMF were visualized using t-SNE, revealing that the BGMF model effectively captures the intrinsic structure and features of molecular fingerprints.]]> 2024/12/4 0:00:00 YAN Xiao-Ying,JIN Yan-Chun,FENG Yue-Hua and ZHANG Shao-Wu 12true Objective Photoacoustic pump-probe imaging can effectively eliminate the interference of blood background signal in traditional photoacoustic imaging, and realize the imaging of weak phosphorescence molecules and their triplet lifetimes in deep tissues. However, background differential noise in photoacoustic pump-probe imaging often leads to large fitting results of phosphorescent molecule concentration and triplet lifetime. Therefore, this paper proposes a novel triplet lifetime fitting method for photoacoustic pump-probe imaging. By extracting the phase of the triplet differential signal and the background noise, the fitting bias caused by the background noise can be effectively corrected.Methods The advantages and feasibility of the proposed algorithm are verified by numerical simulation, phantom and in vivo experiments, respectively.Results In the numerical simulation, under the condition of noise intensity being 10% of the signal amplitude, the new method can optimize the fitting deviation from 48.5% to about 5%, and has a higher exclusion coefficient (0.88>0.79), which greatly improves the fitting accuracy. The high specificity imaging ability of photoacoustic pump imaging for phosphorescent molecules has been demonstrated by phantom experiments. In vivo experiments have verified the feasibility of the new fitting method proposed in this paper for fitting phosphoometric lifetime to monitor oxygen partial pressure content during photodynamic therapy of tumors in nude mice.Conclusion This work will play an important role in promoting the application of photoacoustic pump-probe imaging in biomedicine.]]> 2024/10/5 22:11:35 XIE Zhuo-Jun,ZHONG Hong-Wen,LIU Run-Xiang,WANG Bo,XUE Ping and HE Bin 11true Objective Magnetoencephalography (MEG), a non-invasive neuroimaging technique, meticulously captures the magnetic fields emanating from brain electrical activity. Compared with MEG based on superconducting quantum interference devices (SQUID), MEG based on optically pump magnetometer (OPM) has the advantages of higher sensitivity, better spatial resolution and lower cost. However, most of the current studies are clinical studies, and there is a lack of animal studies on MEG based on OPM technology. Pain, a multifaceted sensory and emotional phenomenon, induces intricate alterations in brain activity, exhibiting notable sex differences. Despite clinical revelations of pain-related neuronal activity through MEG, specific properties remain elusive, and comprehensive laboratory studies on pain-associated brain activity alterations are lacking. The aim of this study was to investigate the effects of inflammatory pain (induced by Complete Freund’s Adjuvant (CFA)) on brain activity in a rat model using the MEG technique, to analysis changes in brain activity during pain perception, and to explore sex differences in pain-related MEG signaling.Methods This study utilized adult male and female Sprague-Dawley rats. Inflammatory pain was induced via intraplantar injection of CFA (100 μl, 50% in saline) in the left hind paw, with control groups receiving saline. Pain behavior was assessed using von Frey filaments at baseline and 1 h post-injection. For MEG recording, anesthetized rats had an OPM positioned on their head within a magnetic shield, undergoing two 15-minute sessions: a 5-minute baseline followed by a 10-minute mechanical stimulation phase. Data analysis included artifact removal and time-frequency analysis of spontaneous brain activity using accumulated spectrograms, generating spectrograms focused on the 4-30 Hz frequency range.Results MEG recordings in anesthetized rats during resting states and hind paw mechanical stimulation were compared, before and after saline/CFA injections. Mechanical stimulation elevated alpha activity in both male and female rats pre- and post-saline/CFA injections. Saline/CFA injections augmented average power in both sexes compared to pre-injection states. Remarkably, female rats exhibited higher average spectral power 1 h after CFA injection than after saline injection during resting states. Furthermore, despite comparable pain thresholds measured by classical pain behavioral tests post-CFA treatment, female rats displayed higher average power than males in the resting state after CFA injection.Conclusion These results imply an enhanced perception of inflammatory pain in female rats compared to their male counterparts. Our study exhibits sex differences in alpha activities following CFA injection, highlighting heightened brain alpha activity in female rats during acute inflammatory pain in the resting state. Our study provides a method for OPM-based MEG recordings to be used to study brain activity in anaesthetized animals. In addition, the findings of this study contribute to a deeper understanding of pain-related neural activity and pain sex differences.]]> 2024/7/24 15:45:28 MIAO Meng-Meng,REN Yu-Xuan,WU Wen-Wei,ZHANG Yu,PAN Chen,LIN Xiang-Hong,LIN Hui-Dan and CHEN Xiao-Wei 10true Objective N6-methyladenosine (m6A), the most prevalent epigenetic modification in eukaryotic RNA, plays a pivotal role in regulating cellular differentiation and developmental processes, with its dysregulation implicated in diverse pathological conditions. Accurate prediction of m6A sites is critical for elucidating their regulatory mechanisms and informing drug development. However, traditional experimental methods are time-consuming and costly. Although various computational approaches have been proposed, challenges remain in feature learning, predictive accuracy, and generalization. Here, we present m6A-PSRA, a dual-branch residual-network-based predictor that fully exploits RNA sequence information to enhance prediction performance and model generalization.Methods m6A-PSRA adopts a parallel dual-branch network architecture to comprehensively extract RNA sequence features via two independent pathways. The first branch applies one-hot encoding to transform the RNA sequence into a numerical matrix while strictly preserving positional information and sequence continuity. This ensures that the biological context conveyed by nucleotide order is retained. A bidirectional long short-term memory network (BiLSTM) then processes the encoded matrix, capturing both forward and backward dependencies between bases to resolve contextual correlations. The second branch employs a k-mer tokenization strategy (k=3), decomposing the sequence into overlapping 3-mer subsequences to capture local sequence patterns. A pre-trained Doc2vec model maps these subsequences into fixed-dimensional vectors, reducing feature dimensionality while extracting latent global semantic information via context learning. Both branches integrate residual networks (ResNet) and a self-attention mechanism: ResNet mitigates vanishing gradients through skip connections, preserving feature integrity, while self-attention adaptively assigns weights to focus on sequence regions most relevant to methylation prediction. This synergy enhances both feature learning and generalization capability.Results Across 11 tissues from humans, mice, and rats, m6A-PSRA consistently outperformed existing methods in accuracy (ACC) and area under the curve (AUC), achieving >90% ACC and >95% AUC in every tissue tested, indicating strong cross-species and cross-tissue adaptability. Validation on independent datasets—including three human cell lines (MOLM1, HEK293, A549) and a long-sequence dataset (m6A_IND, 1 001 nt)—confirmed stable performance across varied biological contexts and sequence lengths. Ablation studies demonstrated that the dual-branch architecture, residual network, and self-attention mechanism each contribute critically to performance, with their combination reducing interference between pathways. Motif analysis revealed an enrichment of m6A sites in guanine (G) and cytosine (C), consistent with known regulatory patterns, supporting the model’s biological plausibility.Conclusion m6A-PSRA effectively captures RNA sequence features, achieving high prediction accuracy and robust generalization across tissues and species, providing an efficient computational tool for m6A methylation site prediction.]]> 2025/8/12 12:53:00 GUO Xiao-Tian,GAO Wei,CHEN Dan,LI Hui-Min and TAN Xue-Wen 9true Objective Fat infiltration has been shown to be closely related to muscle mass loss and a variety of muscle diseases. This study proposes a method based on phase-angle electrical impedance tomography (ΦEIT) to visualize the electrical characteristic response caused by muscle fat infiltration, aiming to provide a new technical means for early non-invasive detection of muscle mass deterioration.Methods This study was divided into two parts. First, a laboratory pork model was constructed to simulate different degrees of fat infiltration by injecting 1 ml or 2 ml of emulsified fat solution into different muscle compartments, and the phase angle images were reconstructed using ΦEIT. Second, a human experiment was conducted to recruit healthy subjects (n=8) from two age groups (20-25 years old and 26-30 years old). The fat content percentage η_fat of the left and right legs was measured by bioelectrical impedance analysis (BIA), and the phase angle images of the left and right calves were reconstructed using ΦEIT. The relationship between the global average phase angle Φ_M and the spatial average phase angle Φ_Mi of each muscle compartment and fat infiltration was further analyzed.Results In the laboratory pork model, the grayscale value of the image increased with the increase of η_fat and Φ_M showed a downward trend. The results of human experiments showed that at the same fat content percentage, the Φ_M of the 26-30-year-old group was about 20%-35% lower than that of the 20-25-year-old group. The fat content percentage was significantly negatively correlated with Φ_M. In addition, the M₂ (soleus) compartment was most sensitive to fat infiltration, and the spatial average phase angles of the M₂ (soleus), M₃ (tibialis posterior and flexor digitorum longus), and M₄ (tibialis anterior, extensor digitorum longus, and peroneus longus) compartments all showed significant inter-group differences.Conclusion ΦEIT imaging can effectively distinguish different degrees of fat infiltration, especially in deep, small or specially located muscles, showing high sensitivity, demonstrating the potential application of this method in local muscle mass monitoring and early non-invasive diagnosis.]]> 2025/7/2 9:24:00 XIAO Wu-Guang,ZHU Xiao-Peng,FENG Hui,SUN Bo,ZHAO Tong and YAO Jia-Feng 8true Objective Cell adhesion is a critical process that regulates cellular physiological functions. Quantitative characterization of adhesion dynamics is essential for elucidating the intrinsic mechanical mechanisms underlying cellular activities. Although atomic force microscopy-based single-cell force spectroscopy is widely used for single-cell adhesion measurements, it requires complex chemical modifications for preparation of live-cell probes, leading to limitations such as cumbersome operation, low throughput, and potential impacts on cell viability. Fluidic force microscopy, which combines atomic force microscopy with microfluidic probes, is a technique allowing the operation of force-controlled nanopipettes in aqueous environments. By applying negative or positive pressure via a pressure controller, a single living cell can be captured onto or released from the cantilever under physiological conditions. This procedure offers a simple workflow and high assay throughput for single-cell adhesion measurements without the need for chemical functionalization. In this study, fluidic force microscopy-based single-cell force spectroscopy was adopted to achieve long-term quantitative characterization of single-cell adhesion dynamics in a simpler and more efficient manner, comparing the dynamic differences in adhesion establishment between two cell lines with different differentiation levels.Methods HEK 293T and hTERT RPE-1 cells were non-invasively captured on the cantilever of a fluidic force microscope via its integrated microfluidic system during 40 h of adhesion culture. Cell-substrate detachment assays were performed, and force-distance curves were recorded to extract key mechanical adhesion parameters, including adhesion force, adhesion energy, and maximum detachment distance. These measurements were combined with real-time monitoring of cell spreading area to systematically characterize the dynamic evolution of single-cell adhesion.Results hTERT RPE-1 cells rapidly entered a stable adhesion phase within 1 h after seeding, with both area-normalized adhesion force and area-normalized adhesion energy reaching peak values. In contrast, HEK 293T cells required 4 h to achieve stable adhesion. Subsequently, the adhesion force, adhesion energy and maximum detachment distance of hTERT RPE-1 and HEK 293T cells stabilized at approximately 240 nN vs. 30 nN, 2.2 pJ vs. 0.12 pJ and 6 μm vs. 4 μm, respectively. hTERT RPE-1 cells reached the peak of area-normalized adhesion parameters earlier than HEK 293T cells, with their peak area-normalized adhesion force and area-normalized adhesion energy being substantially elevated relative to HEK 293T cells. HEK 293T cells presented stronger linear correlations among adhesion energy, maximum detachment distance and adhesion force compared with hTERT RPE-1 cells. For both cell lines, cell spreading area exhibited a weak correlation with adhesion force. Whereas the area-normalized adhesion parameters of HEK 293T cells remained relatively constant throughout the adhesion process, hTERT RPE-1 cells exhibited elevated values in the early phase, followed by a gradual decline. These results indicated distinct dynamic adhesion patterns between the two cell types, with hTERT RPE-1 cells exhibiting stronger adhesion strength and higher adhesion efficiency.Conclusion In this study, fluidic force microscopy-based single-cell force spectroscopy was successfully applied to perform long-term in situ quantitative measurement of the adhesion dynamics in single adherent cells. The approach revealed divergent adhesion patterns between HEK 293T and hTERT RPE-1 cells, suggesting a close association between cell differentiation and adhesion behaviors. These findings provide quantitative mechanical evidence for further understanding the underlying mechanisms of cell adhesion.]]> 2026/6/18 16:24:36 QIN Si-Ying,YOU Tian-Qi,XU Tao,LUO Yan and HU Xi 7true Objective Stroke poses a heavy burden due to its high mortality and morbidity rates. Accurate and real-time detection of lesions is pivotal for prompt clinical intervention and favorable prognosis. Electrical impedance tomography (EIT) and microwave tomography (MWT) have emerged as compelling alternatives for stroke screening, owing to their non-ionizing, non-invasive and portable nature. EIT provides information on tissue conductivity, and MWT offers high sensitivity to changes in dielectric properties. However, single-modality imaging is inherently limited, EIT suffers from low sensitivity to deep-seated tissues and severe ill-posedness of inverse problems, whereas MWT is challenged by strong nonlinearity in inverse scattering and susceptibility to modeling errors. Consequently, the clinical utility of standalone EIT or MWT for stroke diagnosis remains constrained by poor spatial resolution and imaging artifacts. To improve the accuracy and robustness of stroke imaging, a dual-modality fusion conditional denoising diffusion probabilistic model (DM-DDPM) was proposed for high-precision dual-modality image reconstruction.Methods A dual-encoder network with a symmetric architecture and independently trained parameters was constructed to extract heterogeneous features separately from EIT boundary voltage measurements and MWT scattered field signals. Attentional feature fusion (AFF) is employed to integrate complementary information from the two modalities adaptively, generating robust fused priors that suppress redundant noise while preserving key physical characteristics. Subsequently, the fused priors are embedded into a Transformer-based diffusion model via a cross attention mechanism to guide the reverse denoising process. This approach effectively reduces artifacts and enhances the stability of conductivity distribution reconstruction. Time step embedding is introduced to enable the network to perceive the diffusion stage and further improve the accuracy of noise prediction.Results Simulated experiments demonstrated that DM-DDPM significantly outperforms single-modality and multi-modality networks under various noise levels. A head model simulation dataset was constructed based on COMSOL Multiphysics, and tests were carried out under 50 dB, 40 dB and 30 dB signal-to-noise ratio levels. At 30 dB, the average relative error (RE) was below 0.20, while the structural similarity index measure (SSIM) and correlation coefficient (CC) remained above 0.90 and 0.89, respectively. Compared with single-modality and multi-modality networks, artifacts were significantly reduced, lesion edges were clearer, and localization was more accurate. The model maintains high reconstruction quality and strong robustness for single, double, and triple lesions simultaneously. Furthermore, physical experiments were conducted using a 16-electrode EIT system and a 16-antenna MWT system with asynchronous data acquisition. These experiments confirmed the feasibility of the method in real-world scenarios and demonstrated that it can robustly reconstruct simulated lesions despite environmental interference and measurement noise, validating its reliability for practical clinical applications.Conclusion The proposed method effectively combines complementary dual-modality information with a conditional diffusion model. Low accuracy and poor noise resistance in single-modality imaging were effectively addressed, while the noise amplification issue caused by direct multimodal data fusion was avoided. The proposed algorithm exhibits strong anti-noise interference ability and high imaging stability in both simulation and physical experiments. Precise localization of stroke lesions with different quantities was achieved, providing a high-precision, and practical technical support for clinical stroke detection.]]> 2026/4/25 11:33:17 LIU Jin-Zhen,MENG Xiang-Qian,XIONG Hui,ZHOU Li-Min and LI Chun-Chan 6true Objective Discriminating atypical hepatocellular carcinoma (HCC) from other malignancies in liver nodules classified as Liver Imaging Reporting and Data System category M (LR-M) remains a significant diagnostic challenge on conventional ultrasound examination. The LR-M category, originally intended to capture non-HCC malignancies, paradoxically contains up to 63% of atypical HCCs that deviate from classic enhancement patterns, leading to potential misdiagnosis and suboptimal treatment planning. While deep learning has shown promise in HCC diagnosis, most existing models rely exclusively on single-modality ultrasound, overlooking the diagnostic benefits of integrating complementary information from multiple imaging sources. To address this gap, we propose a novel attention-weighted tri-modal ultrasound network (TUS-Net) that integrates contrast-enhanced ultrasound (CEUS), B-mode ultrasound (BUS), and time-intensity curves (TICs) to improve diagnostic accuracy for these clinically challenging lesions.Methods Our framework incorporates a three-dimensional convolutional neural network (C3D) backbone to extract spatiotemporal features from CEUS videos, capturing dynamic vascular patterns critical for lesion characterization. To effectively fuse complementary modalities, we introduce a dual-channel feature fusion module (DCFFM) that adaptively combines features from CEUS and BUS through channel-wise attention mechanisms, allowing the model to dynamically weigh the contribution of each modality based on diagnostic relevance. Additionally, we propose a temporal intensity feature fusion module (TIFFM) that leverages quantitative hemodynamic information from TICs to guide the model’s attention toward diagnostically critical temporal phases, such as arterial wash-in and portal venous washout. The model is further enhanced by automated lesion localization using YOLOX and class activation mapping for interpretability, ensuring that predictions align with clinically meaningful imaging features.Results Evaluated on a tri-modal ultrasound dataset comprising 161 patients with pathologically confirmed LR-M nodules (131 atypical HCC and 30 non-HCC malignancies), our model achieved an accuracy of 86.83%, a sensitivity of 92.50%, a specificity of 75.50%, and an AUC of 89.32% in screening atypical HCC. Compared to single-modality baselines, TUS-Net demonstrated superior specificity, a clinically critical metric given the higher risk associated with misclassifying non-HCC malignancies. Ablation studies confirmed the contribution of each module, with the full model outperforming both standard C3D and 3D ResNet backbones integrated with attention mechanisms. A reader study involving junior and senior radiologists further validated the clinical utility of AI assistance, showing consistent improvements in specificity and inter-reader consistency, particularly for less experienced clinicians.Conclusion These results surpass existing benchmark models and demonstrate the potential of our approach to enhance diagnostic precision in clinically specific cases. By intelligently fusing multi-modal ultrasound data with attention-guided mechanisms, TUS-Net offers a reliable and interpretable tool that holds promise for improving the non-invasive diagnosis of atypical HCC in challenging LR-M liver nodules.]]> 2026/4/16 8:30:33 ZHANG He-Chong,HUANG Liang-Hui,WANG Xue-Hua,JIANG Shang-Lin,CHEN Ying-Ying,ZENG Ya-Guang and ZHENG Wei 5true Objective The widespread adoption of portable fundus cameras for primary care and community screening is hindered by limitations in current autofocus(AF) technologies. Image-based methods relying on sharpness evaluation require iterative searches, resulting in slow convergence, while projection-based techniques are susceptible to optical artifacts and calibration errors. To address these challenges, this study introduces a novel AF system based on direct wavefront sensing, designed to deliver simultaneous high speed, high precision, and operational robustness within the compact form factor essential for portable ophthalmic devices.Methods Our approach fundamentally reimagines the AF process by directly measuring the ocular wavefront aberration. We developed a custom portable fundus camera integrating a miniaturized Shack-Hartmann wavefront sensor (SHWS) into the optical path. An 850 nm laser diode projects a point source onto the retina via oblique illumination to minimize corneal reflections. Light scattered from this spot carries the eye’s refractive error through the imaging optics and is directed to the SHWS, positioned at a plane optically conjugate to the primary color CMOS imaging sensor. A microlens array within the SHWS samples the incident wavefront, generating a pattern of focal spots on a CCD. Real-time centroid analysis of these spots provides a map of local wavefront slopes. These measurements are processed through a singular value decomposition (SVD) algorithm to fit a Zernike polynomial basis set, enabling real-time reconstruction of the wavefront phase. The defocus component (S) is extracted from the second-order Zernike coefficients, providing a direct, quantitative measure of the refractive error in diopters. This value serves as a precise error signal in a closed-loop control system, which commands a voice-coil actuated focusing lens to its null position in a single, deterministic step, eliminating the need for iterative search algorithms.Results Comprehensive evaluation demonstrated the system’s high performance. Testing on a calibrated model eye (OEMI-7) established a highly linear relationship between the computed defocus S and the focusing lens position across a ±20 Diopter (D) compensation range, achievable within a 5 mm mechanical travel. The system achieved a focusing precision of 0.08 D, corresponding to an 18-fold improvement over a conventional projection spot-size method tested under identical conditions. The total focus acquisition time, encompassing wavefront measurement, computation, and lens actuation, averaged under 0.5 s. Clinical validation with 25 human volunteers (50 eyes, refractive range -15 D to +10 D) confirmed practical efficacy. The wavefront-sensing AF succeeded in 92% of attempts with a mean time of 0.5 s, substantially outperforming a projection-based benchmark which achieved only a 32% success rate with an average time of 4.25 s. The system provided instantaneous directional guidance and maintained stability during minor ocular movements. Objective assessment of image quality, via amplitude contrast of retinal vasculature, showed consistent and significant enhancement following AF correction across the entire tested diopter range.Conclusion This work successfully implements and validates a direct wavefront-sensing autofocus paradigm for portable fundus cameras. By directly quantifying and compensating for the optical defocus aberration, this method bypasses the fundamental limitations of image-processing and projection-based techniques, enabling rapid, precise, and deterministic diopter compensation. The developed system delivers an exceptional combination of a wide operational range (±20 D), high accuracy (0.08 D), fast convergence (0.5 s), and a compact physical footprint. This technology provides a practical and high-performance focusing solution capable of enhancing the reliability, throughput, and diagnostic utility of portable retinal imaging in large-scale screening applications. Future efforts will be directed towards system cost optimization and performance adaptation for diverse ocular conditions.]]> 2026/2/11 10:22:25 LIN Zhe-Kai,CHEN Long,ZHENG Geng-Yong,HUANG Jin-Tian,DONG Jia-Xin,YANG Shang-Pan,DING Wen-Zheng,HAN Ding-An,WANG Xue-Hua and ZENG Ya-Guang 4true Objective The most prevalent mRNA modification, N6-methyladenosine (m⁶A) plays an important role in various RNA metabolism, including gene expression and translation. By recruiting different “reader” proteins and their cofactors, m⁶A modification can affect messenger RNA (mRNA) degradation, splicing, nuclear export and translation. However, the selective mechanism by which m⁶A sites regulate mRNA translation through m⁶A reader YTHDF1 binding remains poorly understood, due to a lack of computational methods for identifying context-specific m⁶A sites that regulate translation. To address this, we developed a novel computational framework named m⁶ATEpre, the first tool designed to predict cell-specific m⁶A sites that regulate translation efficiency.Methods m⁶ATEpre integrates multi-omics data, introduces a novel feature representation strategy for m⁶A site sequences, and employs an autoencoder to effectively capture embedded feature representations. Specifically, m⁶ATEpre first integrated MeRIP-seq data and PAR-CLIP data through overlapping m⁶A sites with YTHDF1 binding sites and identified YTHDF1-mediated m⁶A sites. Then, m⁶ATEpre detected the translation gene by analyzing the Ribo-seq data under YTHDF1 knockdown vs control condition. Genes whose translation is mediated by YTHDF1 in an m⁶A-dependent manner were identified by a significant decrease in translation efficiency upon YTHDF1 knockdown. Next, we proposed a binary vector indicating the presence or absence of YTHDF1 binding motifs to characterize each m⁶A site sequence. This represents a novel feature representation strategy for m⁶A sites. m⁶ATEpre utilized the autoencoder to extract the potentially important feature representations and constructed a multilayer perceptron neural networks model to predict potential m⁶A sites that regulating translation efficiency.Results A comprehensive evaluation of m⁶ATEpre was conducted through a series of experiments. We compared its performance against that of a similar prediction task model, as well as other classifiers. The results indicate that m⁶ATEpre achieved the best prediction performance. In addition, we analyzed different feature representation strategies and performed ablation experiments to validate the rationality of the model design. The results demonstrate that our proposed feature representation strategy has a greater advantage in improving prediction performance. In the HeLa cell line, bioinformatic analysis of the metagene distribution and sequence minimum free energy of m⁶A sites regulating translation efficiency (m⁶A-reg-TE sites) revealed their specific properties in translation regulation. Functional enrichment analysis indicated that m⁶A-reg-TE genes are associated with specific biological processes and KEGG pathways. By integrating the binding sites of YTHDF1 co-factors with m⁶A-reg-TE sites, we revealed that YTHDF1-mediated and m⁶A-dependent translation efficiency regulation requires the cooperation of multiple translation-regulatory RNA-binding proteins among its co-factors in the HeLa cell line. Furthermore, we extended our predictions to the dataset of the HEK293T cell line. Similarly, bioinformatic analysis of the metagene distribution and functional enrichment revealed the cell-specific characteristic of these predicted m⁶A-reg-TE sites in HEK293T cells. Likewise, integrated analysis of multiple YTHDF1 co-factors and m⁶A-reg-TE sites predicted in the HEK293T cell line reveals their m⁶A-dependent cooperation in regulating translation efficiency.Conclusion m⁶ATEpre is a timely tool that will advance our understanding of the mechanisms of m⁶A regulation in translation efficiency. The source code and datasets used in this work can be downloaded from https://www.scidb.cn/s/bAZZFr.]]> 2026/3/17 15:08:44 ZHANG Teng,ZHANG Ming,ZHANG Shao-Wu and LIU Lian 3true Objective Photoacoustic tomography (PAT) holds significant potential for high-resolution deep-tissue imaging. In preclinical research, custom-designed concave arc-shaped ultrasound transducer arrays are often used to maximize the detection aperture. However, manufacturing limitations and assembly tolerances frequently cause the actual physical positions of array elements to deviate from their theoretical design. Additionally, concave arrays are typically covered with an acoustic lens, which introduces a mismatch in the speed of sound between the coupling medium and the lens material. The combination of these geometric and acoustic-phase errors leads to severe image artifacts, reduced contrast, and degraded resolution. This study proposes a systematic two-step calibration strategy to address these issues and substantially improve image quality.Methods First, a high-intensity isotropic photoacoustic point source was constructed using a multi-mode optical fiber coated with carbon nanotubes (CNTs) to acquire high signal-to-noise ratio calibration data. The Akaike information criterion (AIC) was employed to accurately determine the time of arrival (ToA) of photoacoustic signals. Subsequently, a geometric calibration algorithm based on nonlinear least-squares (NLS) estimation was developed. This algorithm iteratively solves for the true spatial coordinates of each array element by minimizing the residual between theoretical and measured acoustic path lengths. To further address sound-speed inhomogeneity caused by the acoustic lens, a phase compensation algorithm based on bilinear interpolation was proposed. This algorithm computes a pixel-specific phase delay map across the imaging region and performs point-by-point signal correction during delay-and-sum (DAS) reconstruction. The proposed methods were validated using a custom 96-channel concave arc-shaped array (center frequency: 12 MHz) through both phantom imaging and in vivo mouse tumor models.Results Phantom experiments showed that at an imaging depth of 14 mm, the reconstruction position deviation of the point source in the uncalibrated system reached up to 1 mm. After applying the combined calibration, the lateral resolution (full width at half maximum, FWHM) at the focal point of the arc array reached 95 μm—representing a 85% reduction compared to the uncalibrated state and a 79% reduction compared to geometric calibration alone without phase compensation. In vivo experiments demonstrated that the calibrated system clearly resolved the microvascular network of subcutaneous tumors in mice. Photoacoustic signals were strictly confined within tumor boundaries delineated by ultrasound imaging (USI), eliminating the vascular spillover artifacts commonly observed in uncalibrated images. Furthermore, after intravenous injection of indocyanine green (ICG), the system successfully detected weak photoacoustic signals at a depth of 5 mm, performing significantly better than the uncalibrated system.Conclusion The proposed calibration method, which integrates nonlinear least-squares estimation with phase compensation, significantly improves image fidelity and spatial resolution consistency across a wide field of view by correcting systemic geometric errors and acoustic phase aberrations. This approach demonstrates high robustness and provides a reliable technical foundation for the clinical translation of photoacoustic probes with non-standard geometries.]]> 2026/2/10 11:03:13 TANG Yang,ZHANG Zhan-Jun,HUANG Xing and PENG Kuan 2true Objective Osteoporosis is a progressive metabolic bone disorder characterized by reduced bone mass and microarchitectural deterioration, leading to increased skeletal fragility and susceptibility to fracture. Conventional diagnostic and risk-assessment approaches, such as dual-energy X-ray absorptiometry (DXA) and the FRAX? algorithm, remain limited because they rely primarily on bone mineral density (BMD) and a restricted set of clinical factors, failing to capture the multidimensional determinants of bone strength. This study aimed to develop and validate a deep learning-based multi-dimensional feature fusion model that integrates heterogeneous biological, structural, functional, and genetic information to improve the early identification of osteoporosis and enhance fracture risk prediction.Methods A total of 12 856 participants were aggregated from three major data repositories: the International Osteoporosis Foundation database, a clinical research database on osteoporosis, and a large-scale medical informatics dataset. A unified data-extraction protocol was applied to ensure cross-database harmonization, followed by quality control, variable standardization, and missing-data handling using multiple imputation by chained equations (MICE). A multimodal deep learning framework was constructed to integrate six categories of features: BMD measurements, quantitative bone microarchitecture parameters, bone turnover biomarkers, established clinical risk factors, osteoporosis-related genetic polymorphisms, and sensor-derived balance and gait metrics. A multi-task learning strategy was adopted to simultaneously predict osteoporosis status and 10-year fracture probability. Model training used five-fold cross-validation, and external validation was conducted in an independent clinical cohort. Model performance was benchmarked against DXA alone and the FRAX tool.Results In the internal test cohort, the proposed model achieved an AUC of 0.936 (95% CI: 0.927-0.945), with a sensitivity of 87.5% and a specificity of 91.2%, significantly outperforming DXA alone (AUC=0.889) and FRAX (AUC=0.842) (both P<0.05). External validation yielded an AUC of 0.918 (95% CI: 0.905-0.931) and demonstrated strong calibration (Brier score=0.087). SHAP analyses revealed that, beyond BMD, key predictors included trabecular separation, serum C-terminal telopeptide of type I collagen, balance-related metrics, gait speed, and specific SNPs within the RANKL and VDR loci. A simplified model incorporating only BMD, clinical features, and bone turnover markers preserved high accuracy (AUC=0.917), underscoring its feasibility for resource-limited clinical environments.Conclusion The deep learning-based multi-dimensional feature fusion model markedly enhances the precision and individualization of osteoporosis assessment compared with traditional tools. By integrating biological, structural, metabolic, genetic, and functional dimensions of bone health, the model provides a comprehensive representation of skeletal integrity and robustly improves both diagnostic accuracy and fracture risk prediction. Its strong generalizability across demographic subgroups highlights its clinical applicability. This work offers a promising direction for developing next-generation intelligent decision-support systems that may meaningfully improve osteoporosis screening, risk stratification, and preventive care.]]> 2025/12/2 16:19:41 WANG Chao-Ya and MENG Chao 1true