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北京谱仪(BESⅡ)顶点探测器数据获取系统是北京谱仪数据获取系统的一部分,该子系统电子学采用快总线标准,本文描述了该系统的硬件结构和软件系统,软件包括快总线系统的微码软件和上层控制软件,该系统的死时间为1.5ns,对BESⅡ系统总死时间的贡献小于0.5ms。  相似文献   
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Currently, the pig species is regarded as the most likely organ donor for human xenotransplantation in the future. However, it cannot be granted that the pig will be the optimal species of choice. We have studied human anti-sheep antibodies in comparison with anti-pig antibodies. The anti-sheep lymphocytotoxic and hemagglutination titers were in the range 8 to 128 and 2 to 32, respectively, in single individuals, which were considerably lower than the anti-pig titers of these individuals. Perfusion of sheep kidneys with human blood reduced the anti-sheep xenoantibody titers to zero as measured by lymphocytotoxic, hemagglutination, and sheep aortic endothelial cell antibody binding assays. The perfused kidneys showed generalised depositions of human IgM and C3c in the vascular tree and focal depositions of C1q and fibrin. Obliteration of capillaries by human platelets and polymorphonuclear cells were observed. Total neutral glycolipid fractions were isolated from sheep intestinal, pancreatic, and kidney tissues. By using a chromatogram binding assay, a monoclonal anti-Forssman antibody identified a single compound with five sugar residues in all organs. Several glycolipid bands were stained in all organs by the Gal(alpha)1-specific lectin I-B4 from Griffonia (Bandeiraea) Simplicifolia. A human AB serum pool showed staining by both IgG and IgM antibodies of the Forssman and Gal(alpha)1-terminating components as well as some other, not structurally identified, components. The Forssman and Gal(alpha)1-reactivity in human sera could be eliminated by immunoadsorption using Forssman and Gal(alpha)1-3Gal-immunoadsorbent columns, respectively. Immunostaining of sheep kidney tissue sections showed the presence of Gal(alpha)1-terminating epitopes by immunoperoxidase and immunogold silver staining techniques. Proximal convoluted tubules showed a strong staining, while thin loops of Henle, collecting ducts, urothelium, and vessels showed a weaker staining. Distal convoluted tubules and thick loops of Henle were completely negative. In summary, human serum contains anti-sheep xenoantibodies reacting mainly with the Forssman and Gal(alpha)1-determinants in sheep tissues and the anti-sheep antibody titers are lower than the corresponding anti-pig titers.  相似文献   
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针对3^n阶矩阵的乘法运行,给出了一种分块算法,其乘法运行量比常规的矩阵乘法计算方法和补零的基-2算法都有所减少。  相似文献   
45.
BID: a novel BH3 domain-only death agonist   总被引:1,自引:0,他引:1  
The BCL-2 family of proteins consists of both antagonists (e.g., BCL-2) and agonists (e.g., BAX) that regulate apoptosis and compete through dimerization. The BH1 and BH2 domains of BCL-2 are required to heterodimerize with BAX and to repress cell death; conversely, the BH3 domain of BAX is required to heterodimerize with BCL-2 and to promote cell death. To extend this pathway, we used interactive cloning to identify Bid, which encodes a novel death agonist that heterodimerizes with either agonists (BAX) or antagonists (BCL-2). BID possesses only the BH3 domain, lacks a carboxy-terminal signal-anchor segment, and is found in both cytosolic and membrane locations. BID counters the protective effect of BCL-2. Moreover, expression of BID, without another death stimulus, induces ICE-like proteases and apoptosis. Mutagenesis revealed that an intact BH3 domain of BID was required to bind the BH1 domain of either BCL-2 or BAX. A BH3 mutant of BID that still heterodimerized with BCL-2 failed to promote apoptosis, dissociating these activities. In contrast, the only BID BH3 mutant that retained death promoting activity interacted with BAX, but not BCL-2. This BH3-only molecule supports BH3 as a death domain and favors a model in which BID represents a death ligand for the membrane-bound receptor BAX.  相似文献   
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含油废水处理   总被引:10,自引:0,他引:10  
赵亚乾  徐培 《水处理技术》1995,21(4):227-230
在水量水质调查的基础上,本文提出了以出水回用为目的的含油废水隔油调节沉淀-混凝沉淀-砂滤处理工艺,动态模型试验表明,废水中油和COD的去除率分别达到95%和90%,出水浊度低于2,此水质完全可回用于有关生产车间。  相似文献   
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