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61.
Texture analysis provides a means to quantify complex changes in microscope images. We previously showed that cytoplasmic poly-adenylated mRNAs form mRNA granules in post-ischemic neurons and that these granules correlated with protein synthesis inhibition and hence cell death. Here we utilized the texture analysis software MaZda to quantify mRNA granules in photomicrographs of the pyramidal cell layer of rat hippocampal region CA3 around 1 h of reperfusion after 10 min of normothermic global cerebral ischemia. At 1 h reperfusion, we observed variations in the texture of mRNA granules amongst samples that were readily quantified by texture analysis. Individual sample variation was consistent with the interpretation that animal-to-animal variations in mRNA granules reflected the time-course of mRNA granule formation. We also used texture analysis to quantify the effect of cycloheximide, given either before or after brain ischemia, on mRNA granules. If administered before ischemia, cycloheximide inhibited mRNA granule formation, but if administered after ischemia did not prevent mRNA granulation, indicating mRNA granule formation is dependent on dissociation of polysomes. We conclude that texture analysis is an effective means for quantifying the complex morphological changes induced in neurons by brain ischemia and reperfusion. 相似文献
62.
63.
丁德武 《计算机与应用化学》2012,29(3):347-350
蛋白交互网络在各种细胞功能和生命过程中发挥着至关重要的作用。对它的结构特征进行分析吸引了众多科研人员的关注,功能模块与关键蛋白的识别是其中的重要研究主题。本文主要使用模拟退火算法分析了酵母蛋白交互网络的功能模块,同时结合使用多种中心化指标识别了其中的关键蛋白,并讨论了这些功能模块和关键蛋白的生物学意义。 相似文献
64.
刺突(Spike)蛋白是SARS(Severe Acute Respiratory Syndmme)冠状病毒表面最重要的膜蛋白,它通过与被感染细胞的受体结合来作为感染的媒介。受此启发,该文利用Z曲线方法,对S蛋白及SARS受体序列进行探究,捕捉到一种SARS病毒的可视化特征。大量序列比对的结果证明该特征是SARS病毒所特有的。将这种特征图谱应用到SARS病毒的检测中,可以提供一种非标准的、简单、直观的检验方法,能够诊断一些利用标准方法难以判断的SARS病例。由此可见,Z曲线作为一种基因序列的几何学研究途径是一种有效的研究方法。 相似文献
65.
圆二色谱仪是研究蛋白质二级结构的有力工具,能在远紫外区测出蛋白质的二级结构的各种构象。通常的蛋白质二级结构有α-螺旋、β-折叠、反β-折叠、β-转角及无规则卷曲五种构象,实际观测到的CD谱是这几种二级结构构象CD谱的线性加和。本文利用了奇异值分解最小二乘算法(SVDLS),并编译相关程序解析现场外加电压电解条件下的蛋白质溶液的CD谱,得到几种二级结构构象的组分分布。所得结果与文献报道上的其他方法如SELCON3等相比较,证明是一种快速和有效的方法。 相似文献
66.
This paper introduces an algorithm for finding eukaryotic genes. It particularly addresses the problem of orphan genes, that is of genes that cannot, based on homology alone, be connected to any known gene family and to which it is therefore not possible to apply traditional gene finding methods. To the best of our knowledge, this is also the first algorithm that attempts to compare in an exact way two DNA sequences that contain both coding (i.e. exonic) and non-coding (i.e. intronic and, possibly, intergenic) parts. The comparison is performed following an algorithmical model of a gene that is as close as possible to the biological one (we consider in this paper the “one ORF, one gene” problem only). A gene is seen as a set of exons that are pieces of an assembly and are not independent. The algorithm is efficient enough: although the constants are higher than for usual sequence comparison, its time complexity is proportional to the product of the sequences lengths while its space complexity scales linearly with the length of the smallest sequence. 相似文献
67.
68.
Mike Lafferty Mark J. Dycaico 《Journal of The Association for Laboratory Automation》2004,9(4):200-208
Recombinant approaches for tapping into the biodiversity present in nature for the discovery of novel enzymes and biosynthetic pathways can result in large gene libraries. Likewise, laboratory evolution techniques can result in large but potentially valuable libraries. Thorough screening of these libraries requires ultra high-throughput methods. The GigaMatrix™ screening platform addresses this opportunity using reusable high-density plates with 100,000 to 1,000,000 through-hole wells in a microplate footprint. In addition to throughputs of over 107 wells per day, the platform offers a significant reduction in reagent use and waste, has fully integrated automated “cherry picking,” and uses no complicated dispensing equipment. Wells containing putative hits from targeted fluorescent liquid phase assays are revealed by a fluorescent imaging system. Vision-guided robotics are utilized to recover hits by accessing individual 200 μm and smaller wells with a disposable sterile needle. The GigaMatrix platform has proven to be an effective and efficient tool for screening gene libraries for both discovery and evolution applications. 相似文献
69.
为了研究大豆蛋白纤维这种新型的纺织原料混纺比的测试方法,利用数理统计原理,采用密度梯度法对大豆/涤纶(65/35)混纺纱混纺比进行了测试和计算,该方法不仅可以得到混纺比均值,而且可以得到混纺比标准差,粗纱和细纱混纺比均值的控制范围分别为(63.64%,65.32%)和(64.16%,66.17%),粗纱和细纱混纺比标准差的控制限分别为2.89%和3.56%,同期细纱用溶解法实验结果为64.5%,2种方法误差为1.1%。 相似文献
70.
Scicli Andrea P.; Petrovich Gorica D.; Swanson Larry W.; Thompson Richard F. 《Canadian Metallurgical Quarterly》2004,118(1):5
Fos, the protein product of the immediate early gene c-fos, was used to map functional circuitry underlying contextual conditioned fear. Male rats were given footshocks in a distinctive context and later tested using freezing as the behavioral measure and compared with no-shock and no-retention-test control groups. An increased number of Fos-immunoreactive neurons was found in the lateral part of the central nucleus and in the anterior basolateral and lateral amygdalar nuclei in the brains of the conditioned-fear group compared with controls. Further, a greater number of Fos-immunoreactive neurons was observed in the right central and anterior basolateral nuclei compared with the number of labeled neurons in these structures on the left. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献