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J. W. Brown A. D. Okonmah K. F. A. Soliman A. Carballeira L. M. Fishman 《Cellular and molecular life sciences : CMLS》1988,44(10):898-900
Summary In the presence of ethanol, corticosterone and dexamethasone inhibit choline acetyltransferase and acetylcholinesterase activities in cultured fetal brain cells of the rat. These results suggest that corticosteroids may have an important influence on the activity of cholinergic enzymes in the fetal brain and may antagonize the effects of ethanol in this setting. 相似文献
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本文在分析CCT-88/51/98教学实验系统监控程序的基础上,对该教学实验系统监控程序中存在的问题作出了一些改进。 相似文献
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Evolution of cooperation between individuals. 总被引:1,自引:0,他引:1
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用脸谱图对太子河本溪市区段河流沉积物中重金属污染进行评价的研究 总被引:9,自引:0,他引:9
本文将沉积学原理及国际上新发展的两种重金属污染评价方法与多变量的图表示法——脸谱图相结合,对太子河本溪市区段河道沉积物中重金属的污染状况及潜在生态危害进行了综合性的评价研究。从脸谱图上可以直观地看出各采样点重金属的污染情况和潜在生态危害程度。从研究结果可以看出,太子河本溪市区段河道沉积物中重金属的污染是很严重的。 相似文献
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The units of calcium conduction in Helix neurones 总被引:4,自引:0,他引:4
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Neurons and other cells, such as those of epithelia, accumulate particular proteins in spatially discrete domains of the plasma membrane. This enrichment is probably important for localization of function, but it is not clear how it is accomplished. One proposal for epithelial cells is that proteins contain targeting signals which guide preferential accumulation in basal or apical membranes. The growth-cone membrane of a neuron serves as a specialized transduction system, which helps to convert cues from its environment into regulated growth. Because it can be physically separated from the cell soma, it has been possible to show that the growth-cone membrane contains a restricted set of total cellular proteins, although, to our knowledge, no proteins are limited to that structure. One of the most prominent proteins in the growth-cone membrane is GAP-43. Basi et al. have suggested that the N-terminus of GAP-43 might be important for the binding of GAP-43 to the growth-cone membrane. Skene and Virag recently found that the cysteines in the N-terminus are fatty-acylated and that this post-translational modification correlates with membrane-binding ability. We investigated the binding of GAP-43 to the growth-cone membrane by mutational analysis and by laser-scanning confocal microscopy of fusion proteins that included regions of GAP-43 and chloramphenicol acetyltransferase (CAT). We found that a short stretch of the GAP-43 N-terminus suffices to direct accumulation in growth-cone membranes, especially in the filopodia. This supports a previous proposal for the importance of this region of GAP-43 in determining the membrane distribution of GAP-43. 相似文献