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131.
132.
MIPS/W8位低功耗嵌入式RISC MCU核的设计 总被引:4,自引:0,他引:4
介绍了一种8位低功耗嵌入式RISC MSC核的设计.该核采用哈佛结构,三级流水线,单周期指令,指令集与PIC16C57相兼容.本文还对系统结构设计及各单元模块设计进行了分析. 相似文献
133.
基于可寻址分支分配器的CATV收费系统 总被引:2,自引:1,他引:1
给出了一种基于可寻址分支分配器的CATV收费管理系统设计方案,并着重介绍了系统的工作原理及可寻址分支分配器的设计。 相似文献
134.
A broadly cross-protective monoclonal antibody binding to Escherichia coli and Salmonella lipopolysaccharides 总被引:1,自引:0,他引:1
FE Di Padova H Brade GR Barclay IR Poxton E Liehl E Schuetze HP Kocher G Ramsay MH Schreier DB McClelland 《Canadian Metallurgical Quarterly》1993,61(9):3863-3872
During the last decade, episodes of sepsis have increased and Escherichia coli has remained the most frequent clinical isolate. Lipopolysaccharides (LPS; endotoxin) are the major toxic and antigenic components of gram-negative bacteria and qualify as targets for therapeutic interventions. Molecules that neutralize the toxic effects of LPS are actively investigated. In this paper, we describe a murine monoclonal antibody (MAb; WN1 222-5), broadly cross-reactive and cross-protective for smooth (S)-form and rough (R)-form LPS. As shown in enzyme-linked immunosorbent assay and the passive hemolysis assay, WN1 222-5 binds to the five known E. coli core chemotypes, to Salmonella core, and to S-form LPS having these core structures. In immunoblots, it is shown to react with both the nonsubstituted core LPS and with LPS carrying O-side chains, indicating the exposure of the epitope in both S-form and R-form LPS. This MAb of the immunoglobulin G2a class is not lipid A reactive but binds to E. coli J5, an RcP+ mutant which carries an inner core structure common to many members of the family Enterobacteriaceae. Phosphate groups present in the inner core contribute to the epitope but are not essential for the binding of WN1 222-5 to complete core LPS. Cross-reactivity for clinical bacterial isolates is broad. WN1 222-5 binds to all E. coli clinical isolates tested so far (79 blood isolates, 80 urinary isolates, and 21 fecal isolates) and to some Citrobacter, Enterobacter, and Klebsiella isolates. This pattern of reactivity indicates that its binding epitope is widespread among members of the Enterobacteriaceae. WN1 222-5 exhibits biologically relevant activities. In vitro, it inhibits the Limulus amoebocyte lysate assay activity of S-form and R-form LPS in a dose-dependent manner and it neutralizes the LPS-induced release of clinically relevant monokines (interleukin 6 and tumor necrosis factor). In vivo, WN1 222-5 blocks endotoxin-induced pyrogenicity in rabbits and lethality in galactosamine-sensitized mice. The discovery of WN1 222-5 settles the long-lasting controversy over the existence of anti-core LPS MAbs with both cross-reactive and cross-protective activity, opening new possibilities for the immunotherapy of sepsis caused by gram-negative bacteria. 相似文献
135.
VM Coiro AL Segre A Di Nola M Paci A Grottesi G Veglia A Ballio 《Canadian Metallurgical Quarterly》1998,257(2):449-456
Pseudomycin A is a cyclic lipodepsinonapeptide phytotoxin produced by a strain of the plant pathogenic bacterium Pseudomonas syringae. Like other members of this family of bacterial metabolites, it is characterised by a fatty acylated cyclic peptide with mixed chirality and lactonic closure. Several biological activities of Pseudomycin A are lower than those found for some of its congeners, a difference which might depend on the diverse number and distribution of charged residues in the peptide moiety. Hence, it was of interest to investigate its conformation in solution. After the complete interpretation of the two-dimensional NMR spectra, NOE data were obtained and the structure was determined by computer simulations, applying distance geometry and molecular dynamics procedures. The conformation of the large ring of Pseudomycin A in solution includes three rigid structural regions interrupted by three short flexible regions that act as hinges. The overall three-dimensional structure of the cyclic moiety is similar to that of previously studied bioactive lipodepsinonapeptides produced by other pseudomonads. 相似文献
136.
MG Tozzi-Ciancarelli C Di Massimo G Ascani A Corbacelli 《Canadian Metallurgical Quarterly》1998,18(2-3):151-156
A number of retinal proteins are phosphorylated by a variety of kinases, resulting in well-known regulatory effects. The identity and role of corresponding phosphatases is less clear. We simultaneously measured the activity of serine/ threonine protein phosphatases type 1, 2A and 2C in bovine retinae. The enzymes were classified according to substrate specificity, divalent cation requirement and the effect of phosphatase subtype-specific inhibitors. The total- and specific activity of phosphatase type 2A was prevalent. Type 2C was 10-fold less abundant. 80% of type 1 and 50% of type 2A and type 2C, respectively, were soluble. An economic purification scheme was developed. We demonstrated the presence of phosphatase isozymes 2Calpha and 2Cbeta in bovine rod outer segments by enzymatic analysis as well as immunological techniques. The results suggest a yet unknown role of phosphatase type 2C in phototransduction. On the other hand, the immense amount of protein phosphatases found to be soluble - therefore not associated with rod outer segment membranes - points towards participation of these enzymes in the process of visual transduction not considered thus far. 相似文献
137.
建设方自行招标与专职代理机构招标的比较 总被引:1,自引:0,他引:1
通过对水利工程建设方自行招标与专职招标代理机构招标两种招标形式的对比,对我国现阶段推行的委托专职招标代理机构进行招标的必要性作进一步说明。 相似文献
138.
大伙房水库输水工程TBM维修保养管理模式设计 总被引:1,自引:0,他引:1
1 TBM维修管理模式1·1 TBM维修管理模式的源起和思路通过发达国家设备管理模式和我国施工现场设备管理实际情况的比较,国内设备管理工作的成效很大程度上取决于企业的决策者对该项工作的认识,管理水平的高低相差甚远,换一个领导班子就换一种思路,换一批工人就换一种做法,随意性和盲目性比较突出。要改变此状况,可行的做法就是:学习先进的管理经验,设备管理变“人治”为“法治”,制定出科学合理、切实可行的维修保养的模式,形成规范化、标准化、操作性强的文件,作为今后现场设备维修保养的依据。基于此,设备部门在设备安装阶段,利用引进… 相似文献
139.
适用于高速长途DWDM系统的色散管理线路 总被引:1,自引:0,他引:1
对于高速长途密集波分复用(DWDM)传输,必需采用各种各样的色散补偿、色散管理技术,其中,交替使用正负色散光纤构成色散管理线路(DML)是可行的解决方案之一,在国际上已经取得显著进展,正成为人们关注的焦点,国内在这方面的研究报道还少见.文章以高速长途DWDM系统对传输线路的性能要求为基础,综述了有代表性的3种不同类型的DML的特点和最新进展。 相似文献
140.
指出湖滨带是连接湖泊水体和陆地的一个功能过渡界面区。它作为生物的重要栖息地,具有净化水质、缓解波浪等多种功能。因此,对湖滨带实行生态恢复建设,应予以高度的重视。笔者通过具体工程的实践,阐述了湖滨带生态恢复建设工程的特点、施工阶段的监理工作,以及对监理人员的素质要求,可供类似工程借鉴、参考。 相似文献