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101.
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肝癌先天性多表达多药耐药基因,严重影响肝癌的化疗效果,筛选肝癌细胞中的耐药基因,研究其耐药机制有助于提高肝癌化疗效果,提高肝癌的治愈率。首先构建肝癌细胞逆转录病毒的cDNA文库,感染成纤维细胞,使得逆转录病毒基因整合进细胞,加药筛选,存活细胞中的基因再次包装成病毒,用于下一轮筛选。采用循环包装回收(Cyclical packaging rescue,CPR)技术进行肝癌细胞耐药基因的筛选即是通过病毒包装将基因从细胞中钓取出来,相比于常规筛选方法,仅通过一轮筛选可能会出现很多假阳性基因,采用CPR技术则是通过多轮筛选,很大程度减少了假阳性细胞的出现。通过该方法经过四轮筛选获得核糖体蛋白S11(RPS11)、核糖体蛋白L6(RPL6)、核糖体蛋白L11(RPL11)、核糖体蛋白L24(RPL24)等几种基因,经初步检测,增加了细胞的耐药性。 相似文献
104.
ROC曲线分析在评价入侵物种分布模型中的应用 总被引:67,自引:0,他引:67
生态位模型(ecological niche models,ENMs)已广泛应用于物种潜在分布区预测,ENMs的应用也为外来入侵物种的风险分析提供了重要的定量化分析工具,但如何评价不同模型之间的预测效果成了当今研究的热点问题。本文介绍了受试者工作特征(ROC)曲线分析在评价不同生态位模型预测效果中的应用原理和分析方法,并以一种植物病原线虫-相似穿孔线虫(Radopholus similis)为例,应用ROC曲线分析法对其5种模型(BIOCLIM,CLIMEX,DOMAIN,GARP,MAXENT)的预测结果进行了比较分析。5种模型的ROC曲线下面积AUC(Area Under Curve)值分别为0.810,0.758,0.921,0.903和0.950,以MAXENT模型的AUC值最大,表明其预测效果最好;方差分析结果表明,除GARP与DOMAIN模型之间AUC值差异不显著外,其余各模型之间差异显著。 相似文献
105.
106.
应用聚合酶链式反应技术(PCR)扩增轮状病毒VP7基因,并将其克隆到pMD18-T simple载体上,对重组子进行PCR检测和限制性内切酶分析,并测定DNA全序列。结果显示,克隆片段全长为981 bp。将轮状病毒VP7基因定向的克隆到原核表达载体pET-32a启动子下游,构建原核表达载体pET-32aVP7。将质粒pET-32aVP7转化Transetta表达菌株进行诱导表达,裂解菌体细胞抽提蛋白质进行SDS-PAGE。结果表明,轮状病毒壳蛋白VP7基因在Transetta表达菌株内得到成功表达。 相似文献
107.
Combinatorial signals of activin/nodal and bone morphogenic protein regulate the early lineage segregation of human embryonic stem cells 总被引:2,自引:0,他引:2
Wu Z Zhang W Chen G Cheng L Liao J Jia N Gao Y Dai H Yuan J Cheng L Xiao L 《The Journal of biological chemistry》2008,283(36):24991-25002
Cell fate commitment of pre-implantation blastocysts, to either the inner cell mass or trophoblast, is the first step in cell lineage segregation of the developing human embryo. However, the intercellular signals that control fate determination of these cells remain obscure. Human embryonic stem cells (hESCs) provide a unique model for studying human early embryonic development. We have previously shown that Activin/Nodal signaling contributes to maintaining pluripotency of hESCs, which are derivatives of the inner cell mass. Here we further demonstrate that the inhibition of Activin/Nodal signaling results in the loss of hESC pluripotency and trophoblast differentiation, similar to BMP4-induced trophoblast differentiation from hESCs. We also show that the trophoblast induction effect of BMP4 correlates with and depends on the inhibition of Activin/Nodal signaling. However, the activation of BMP signaling is still required for trophoblast differentiation when Activin/Nodal signaling is inhibited. These data reveal that the early lineage segregation of hESCs is determined by the combinatorial signals of Activin/Nodal and BMP. 相似文献
108.
Nanomedicine is an emerging field that integrates nanotechnology, biomolecular engineering, life sciences and medicine; it is expected to produce major breakthroughs in medical diagnostics and therapeutics. Due to the size-compatibility of nano-scale structures and devices with proteins and nucleic acids, the design, synthesis and application of nanoprobes, nanocarriers and nanomachines provide unprecedented opportunities for achieving a better control of biological processes, and drastic improvements in disease detection, therapy, and prevention. Recent advances in nanomedicine include the development of functional nanoparticle based molecular imaging probes, nano-structured materials as drug/gene carriers for in vivo delivery, and engineered molecular machines for treating single-gene disorders. This review focuses on the development of molecular imaging probes and engineered nucleases for nanomedicine, including quantum dot bioconjugates, quantum dot-fluorescent protein FRET probes, molecular beacons, magnetic and gold nanoparticle based imaging contrast agents, and the design and validation of zinc finger nucleases (ZFNs) and TAL effector nucleases (TALENs) for gene targeting. The challenges in translating nanomedicine approaches to clinical applications are discussed. 相似文献
109.
Pablo Perez Goodwyn Jintong Wang Zhouyi Wang Aihong Ji Zhendong Dai Kenji Fujisaki 《Central European Journal of Biology》2008,3(3):299-306
We measured the force of free pulling water striders, using a hair attached to their backs and a 3D strain gauge force sensor.
We showed the repeatability and accuracy of this method. The error of the method was estimated by comparing the projected
angles of the force vector on each plane derived from the force data, with those angles derived from video recordings, and
was estimated as 12.4%. Females on average were stronger (1.32 mN) than males (0.87 mN), however the ratio of force/weight
was not significantly different. Compared with other lighter species, A. paludum seems to be stronger, but the force/weight ratio is actually lower as expected. A. paludum applies about 0.30–0.40 mN/cm with its mid-legs, thus avoiding penetrating the surface tension while propelling itself rapidly
over the water.
The corresponding author, Dr Pablo Perez Goodwyn, submitted this article [1] to Central European Journal of Biology (CEJB)
shortly after submitting the article [2] to Journal of Bionic Engineering (JBE). JBE published it as a research article in
June 2008, and in July 2008 the article was published as a communication in CEJB. Since there are significant unacknowledged
similarities between the two papers, it has been brought to the attention of the authors that duplicate submission and publication
have taken place. The editors of CEJB consider this an infringement of professional ethics and
therefore the decision has been made to retract the article published in Central European Journal of Biology.
[1] An accurate method to directly measure water strider’s stroke force on the water (Aquarius paludum: Heteroptera: Gerridae),
Central European Journal of Biology, Vol. 3, No. 3, 2008, pp. 299–306
[2] Water striders: the biomechanics of water locomotion and functional morphology of the hydrophobic surface (Insecta: Hemiptera-Heteroptera),
Journal of Bionic Engineering, Vol. 5, No. 2, 2008, pp. 121-126 相似文献
110.
为了研究ApCl基因的功能,应用基因重组技术将ApCl基因片段克隆入大肠埃希菌—酵母穿梭质拉pGAPZαA,构建重组真核表达质拉pGAPZαA-ApCl,电转化巴斯德单赤酵母GS115,Zeocin筛选出阳性克隆转化子.通过比较转化空载体pGAPZaA和重组载体pGAPZαA-ApCl的不同菌株分别在含有高盐和高山梨醇浓度的液体培养基中生长情况,发现毕赤酵母GS115在转化ApCl基因后其抗旱、抗盐能力显著提高(约3倍),进一步验证了ApCl基因对提高生物抗逆能力有显著作用,为将来分离该蛋白及进一步研究奠定基础. 相似文献