196 resultados para 327.421


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This work was supported by grants from the National Basic Research Program of China (973 Program, 2007CB411600), the National Natural Science Foundation of China (30621092, 30623007), and Bureau of Science and Technology of Yunnan Province.

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该试验利用 Apal,BamHI,BclI,BglI,BglⅡ,DraI,EcoRI,EcoRV,HaeⅡ,HindⅢ, KpnI,PstI,PvuⅡ,SacI,SalI,SmaI 和 X hoI 计18种限制性内切酶, 研究了来自欧洲、非洲及国内的5个山羊品种共计33只个体的 mtDNA, 共检测出27种限制性态型,可归结为8种单倍型. 结果表明, 国内2个山羊品种的基本单倍型为 BamHl-A, Bcl, I-B, ClaI-A, EcoRI-A, EcoRV- A, HaeIIA, HindIII-C和PvuⅡ-A, 以及为 BamHl-A,BcII-A,ClaI-A, EcoRI-A, EcoRV-A, HaeⅡ-A, HindIII-C和PvuⅡ-A.II一A, 而欧洲及非洲3个山羊品种基本的单倍型为BamHl-B, BcII-A, ClaI-A, EcoRI-A, EcoRV-A, HaeⅡ-A, HindIII-B和PvuⅡ-A,这一结果提示本研究几个受试山羊品种可能有两种不同的母系来源; 同时, 各品种的分子聚类图也表明国内2个山羊品种间具有较近的亲缘关系, 而欧洲品种和非洲3个品种间的亲缘关系较近, 这一结果也支持上述几个受试山羊品种可能有不同野生祖先的结论, 同时也验证了欧洲品种萨能羊曾引入过奴比羊的事实。

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利用同功酶淀粉凝胶电泳技术检测了来自甘肃摩天岭和陕西秦岭两个地区的19只川金丝猴(Rhinopithecus roxellanae)的44个遗传座位,没有发现多态座位,其平均遗传杂合度为0。这与滇金丝猴(R. bieti)的平均遗传杂合度处于同一水平。结合古地质学的数据推测,川金丝猴如此之低的遗传多样性很可能是由于历史上受到过瓶颈效应的打击,仅有少数种群得以幸存。在这之后,川金丝猴发生了种群扩张,从而形成了现在的地理分布格局。

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该文报道: 用XAD-2离子树脂吸附富集法制备自来水和滇池及松华坝水库源水提取物, 以 Ames 鼠伤寒沙门氏菌回复突变系统诱发致突变性. Ames 试验结果如下; 来自滇池源水经氯化的自来水提取物, 用TA_(98)菌株加S_(9)或不加S_(9)混合物, 突变率>2, 结果为阳性. 滇池源水提取物致突变性为可疑. 使用化学分析法结合生物分析法评价昆明自来水和滇池及松华坝水库水中的化学微量污染物, 估价在水中的微量污染物对人体健康的潜在致癌效应是有意义的。

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For developing efficient vaccines, it is essential to identify which amino acid changes are most important to the survival of the virus. We investigate the amino acid substitution features in the Avian Infectious Bronchitis Virus (AIBV) antigenic domain o

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Human immunodeficiency virus-1(HIV-1)辅助蛋白在其感染和艾滋病发病过程中起着非常重要的作用.Regulator of expression of virion proteins(Rev)作为HIV-1辅助蛋白之一,可以调节病毒结构蛋白mRNA出核转运和蛋白表达,对于病毒的复制至关重要.为研究Rev蛋白对靶细胞表犁和功能的影响,本实验采用电穿孔的方法,将HIV-1的rev基因导入THP-1细胞,通过流式分选结合G418筛选的方法建立稳定表达Rev蛋白的细胞模型;并通过RT-PCR、荧光观察及流式检测的方法,在mRNA和蛋白两个水平对所建立的细胞模犁进行鉴定.结果证实rev基凶成功导入了THP-1细胞并稳定表达,为后续rev基因产物与细胞相互作用的研究提供了平台.

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 从天然药物中寻找高效低毒的抗HIV/ AIDS 活性化合物和先导化合物是国内外新药研制中非 常活跃的领域之一,也应该是我国近期创制新药的一条捷径。来源于动植物、海洋生物、微生物以及人体等中 的许多天然化合物具有抗HIV 活性。本文仅对天然来源的多肽和蛋白类化合物抗HIV 的研究简要综述。

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Behavioral stress can either block or facilitate memory and affect the induction of long-term potentiation (LTP) and long-term depression (LTD). However, the relevance of the stress experience-dependent long-term depression (SLTD) to spatial memory task is unknown. Here we have investigated the effects of acute and sub-acute elevated platform (EP) and foot shock (FS) stress on LTD induction in CA1 region of the hippocampus of anesthetized rats and spatial memory in Morris water maze. We found that LTD was facilitated by acute EP stress, but not by sub-acute EP stress that may be due to the fast adaptation of the animals to this naturalistic mild stress. However, FS stress, an inadaptable strong stress, facilitated LTD induction both in acute and sub-acute treatment. In addition, with the same stress protocols, acute EP stress impaired spatial memory but the sub-acute EP stressed animals performed the spatial memory task as well as the controls, may due to the same reason of adaptation. However, acute FS stress slightly impaired learning but sub-acute FS even enhanced memory retrieval. Our results showed that SLTD was disassociated with the effect of stress on memory task but might be related to stress experience-dependent form of aberrant memory. (C) 2003 Elsevier Science Ireland Ltd. and the Japan Neuroscience Society. All rights reserved.

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本研究以体外无血清培养的人早期绒毛细胞滋养层细胞和绒毛组织培养为模型,测定了天花粉蛋白对滋养层细胞hCG、孕酮分泌的影响,发现体外无血清培养的细胞滋养层细胞分泌的hCG在天花粉蛋白浓度为0.1μg/ml即下降50%,而后下降缓慢,8μg/ml以上方降为零,而绒毛组织培养在天花粉蛋白浓度为0.1μg/ml时hCG下降近90%,而后下降缓慢,至8μg/ml以上降到零,说明体外培养的细胞滋养层细胞中有两个群体,其中一个对天花粉蛋白敏感,另一个不敏感,尽管在形态上很难区别。孕酮的反应则不同,在细胞滋养层细胞和绒毛组织培养中,随天花粉蛋白浓度升高,孕酮分泌均缓慢下降,未出现两阶段下降过程。

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国家自然科学基金

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