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美国麻省理工学院(MIT)营养和食品科学系工业微生物学教授A. L. Demain教授偕其夫人,于1982年5月24日—6月5日来华进行学术访问。先后在上海和北京访问了中国科学院和 相似文献
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Biologia Plantarum - Azokopula?ními metodami (α naftylacetát, resp. naftolacetát AS + fast blue RR) byla prokázána esterasa v ko?enové ?pi?ce... 相似文献
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著名生化学家莱洛伊尔L.F.(Leloir Luis F.)生于1906年,死于1987年12月4日。他的初期贡献之一且立即引人注目的,是发现了葡萄糖-1,6-二磷酸及葡萄糖-1,6-二磷酸作为磷酸葡萄糖变位酶辅助因子的作用。效仿于此,科里、萨瑟兰和帕斯特纳克一起,提出作为磷酸甘油酸变位酶的2,3双二磷酸甘油酸的类似作用的提议。在莱洛伊尔的重大发 相似文献
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Jonathan R. Fritz Ryan W. Loney Stephen B. Hall Stephanie Tristram-Nagle 《Biophysical journal》2021,120(2):243-253
To determine how different constituents of pulmonary surfactant affect its phase behavior, we measured wide-angle x-ray scattering (WAXS) from oriented bilayers. Samples contained the nonpolar and phospholipids (N&PL) obtained from calf lung surfactant extract (CLSE), which also contains the hydrophobic surfactant proteins SP-B and SP-C. Mixtures with different ratios of N&PL and CLSE provided the same set of lipids with different amounts of the proteins. At 37°C, N&PL by itself forms coexisting Lα and Lβ phases. In the Lβ structure, the acyl chains of the phospholipids occupy an ordered array that has melted by 40°C. This behavior suggests that the Lβ composition is dominated by dipalmitoyl phosphatidylcholine (DPPC), which is the most prevalent component of CLSE. The Lβ chains, however, lack the tilt of the Lβ′ phase formed by pure DPPC. At 40°C, WAXS also detects an additional diffracted intensity, the location of which suggests a correlation among the phospholipid headgroups. The mixed samples of N&PL with CLSE show that increasing amounts of the proteins disrupt both the Lβ phase and the headgroup correlation. With physiological levels of the proteins in CLSE, both types of order are absent. These results with bilayers at physiological temperatures indicate that the hydrophobic surfactant proteins disrupt the ordered structures that have long been considered essential for the ability of pulmonary surfactant to sustain low surface tensions. They agree with prior fluorescence micrographic results from monomolecular films of CLSE, suggesting that at physiological temperatures, any ordered phase is likely to be absent or occupy a minimal interfacial area. 相似文献
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Aβ ion channels. Prospects for treating Alzheimer's disease with Aβ channel blockers 总被引:1,自引:0,他引:1
The main pathological features in the Alzheimer’s brain are progressive depositions of amyloid protein plaques among nerve cells, and neurofibrillary tangles within the nerve cells. The major components of plaques are Aβ peptides. Numerous reports have provided evidence that Aβ peptides are cytotoxic and may play a role in the pathogenesis of AD. An increasing number of research reports support the concept that the Aβ-membrane interaction event may be followed by the insertion of Aβ into the membrane in a structural configuration which forms an ion channel. This review summarizes experimental procedures which have been designed to test the hypothesis that the interaction of Aβ with a variety of membranes, both artificial and natural, results in the subsequent formation of Aβ ion channels We describe experiments, by ourselves and others, that support the view that Aβ is cytotoxic largely due to the action of Aβ channels in the cell membrane. The interaction of Aβ with the surface of the cell membrane may results in the activation of a chain of processes that, when large enough, become cytotoxic and induce cell death by apoptosis. Remarkably, the blockage of Aβ ion channels at the surface of the cell absolutely prevents the activation of these processes at different intracellular levels, thereby preserving the life of the cells. As a prospect for therapy for Alzheimer’s disease, our findings at cellular level may be testable on AD animal models to elucidate the potential role and the magnitude of the contribution of the Aβ channels for induction of the disease. 相似文献
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《华东昆虫学报》2011,(2)
1. Contact Information Aarhus University, Department ofAgroecology & Environment, Flakkebjerg Research Centre, DK-4200 Slagelse, Denmark and Department of Biological Invasions, Plant Protection Institute, CAAS, #12 South Street of Zhong-Guan-Cun, Beijing, 100081, China Phone: +45-87158224 / +45-87156082 E-mail: gabor.lovei@agrs 相似文献