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DNA的非线性动力学特性和它的功能
用新建立的非线性动力学模型研究了DNA的非线性特性及它的复制与遗传,转录和转译等生物功能.这个新的模型强调了碱基氢键中的氢原子的独特作用,使用了三个动力学变量来描述氢原子在双Morse势中的振动及碱基的振动与转动,并充分考虑了三个运动模之间的耦合效应.应用这模型得到了复制与转录的特性,说明了DNA的分型特征及D-DNA-A-DNA以及B-DNA-Z-DNA等的相变机制及特性....
2020-08-31 10:42:30浏览：59
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聚赖氨酸-聚乙二醇-聚赖氨酸与DNA聚离子复合物胶束的研究
将聚(Nε-苄氧羰基赖氨酸)-聚乙二醇-聚(Nε-苄氧羰基赖氨酸)(PLL(Z)-PEG-PLL(Z))中的氨基去保护得到两端为聚阳离子的嵌段共聚物聚赖氨酸-聚乙二醇-聚赖氨酸(PLL-PEG-PLL),并对其与DNA结合形成的聚集体的性质进行了研究.结果表明:PLL-PEG-PLL与DNA形成了聚离子复合物胶束;DNA与PLL通过静电作用形成核,PEG包裹在其外面,得到的聚离子复合物胶束为均相体系,即使在化学计量点也不会沉淀,保持着很好的流动性和稳定性,这一点对基因治疗是很重要的;而且随着PLL段的增加,包覆效果更好;聚离子复合物胶束使得DNA具有较强的核酶抗性;大小在10～35nm之间,呈球形;聚离子复合物胶束能够用于基因的传递,使基因在昆虫细胞系SF9中能够表达出蛋白质....
2020-07-10 14:39:05浏览：184
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64. Study on the DNA damage induced by coal tar pitch fume extracts in rat alveolar macrophage and i
The carcinogenic mechanism of coal tar pitch (CTP) as a recognized carcinogen has been studying. It is widely believed that the carcinogenicity of CTP is based on the genotoxicity of CTP. In the process of carcinogenesis caused by extrinsic chemical substance, the DNA damage mainly occurred in the initiation phase. UP to now, the most sensitive detecting endpoint for DNA damage is to detect DNA single strand breaks. The single cell gel electrophoresis has been rapidly becoming a widely used analytical procedure during the last few years, which can detect DNA strand breaks. The method is a fast, relatively inexpensive, easy to perform, non-radioactive, and very sensitive method. This method suits to different tests in vitro or in vivo. Virtually any eukaryotic cell, which could be made into single cell suspensions, can be processed for analysis of DNA damage using the single cell gel electrophoresis. The aim of the study is to investigate the role of DNA damage induced by CTP fume in rat AM, to examine the changes of ROS, MDA and SOD, and to explore the mechanism of DNA damage by CTP fume. The present study is in favor of studying the mechanism of mutagenesis and carcinogenesis induced by CTP. Method: The healthy male Wistar rats were anesthetized intraperitoneally with 40 mg pentobarbital sodium per kilogram of body weight. The animals were exanguinated by excising femoral, and collected the rat alveolar macrophage by Joseph's method. The concentration of AM had been regulated to 1.5×106 cell/ml. AMs, which had been cultured in 24-well culture plate, were divided into 4 groups. These cells were exposured to 5.0 μg/ml extracts of coal tar pitch fume, and contacted with 500 μM, 1 000 μM, and 2 000 μM of GSH respectively. These cells were divided into 4 groups. After incubation 24 hours, the indexes that had been used above were measured. Results: ①The DNA strand breaks induced by coal tar pitch fume extracts: After undergoing electrophoresis, the ‘comet’ cells are seldom in control group, but the ‘comet’ cells increased significantly in experimental groups. When the concentration of CTP fume extracts increased from 0 to 10.0 μg/ml, the incidences of ‘comet’ cell increased from 6.0% to 92.0%. There were significant differences in all groups (P...
2020-06-12 16:19:30浏览：1444
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生物软物质研究的新进展
文章对近年来中科院物理研究所软物质物理实验室生物软物质研究的部分新进展做一简略介绍,包括DNA单分子研究,DNA与组蛋白的相互作用动力学研究,生物分子马达的运动机制研究,解旋酶与DNA的结合以及解旋DNA的动力学研究,朊病毒片段聚集的分子动力学研究,蛋白质折叠动力学的脉冲升温-时间分辨光谱研究,光合细菌外周捕光天线膜蛋白的拓扑结构研究等....
2020-06-12 15:41:09浏览：1444
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