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1.
Development of City Transport System and Two-wheel Vehicles   总被引:1,自引:0,他引:1  
Based on the study on the city transport systems of some typical cities worldwide, this paper put forward that each city transport system has its own development mode, which is influenced by the city development plan, economic development level, traveling vehicle composition etc.. When some problems occur, such as the congestions caused by contradiction between the road capacity and vehicle composition, the city transport system may come into temporary maturity period. If the improvement for road system is limited meanwhile, optimized structure of vehicle composition should be an effective solution in this case. With the development of economy-internationalization, the development speed of city transport modernization is rapid. When traveling easiness is conflicting with efficiency, the advantages of public transport system become more obvious. Correspondingly, the superiority of two-wheel vehicles will reappear. Though the important function of two-wheel vehicles for alleviating city traffic problems i  相似文献   
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G A Cottrell 《Nature》1970,225(5237):1060-1062
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G A Cottrell  N N Osborne 《Nature》1970,225(5231):470-472
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The amino acid sequence of the alpha-chain of human fibrinogen.   总被引:33,自引:0,他引:33  
The amino acid sequence of the human fibrinogen alpha-chain reveals a structure that can be divided into three zones of unique amino acid composition. The middle of these contains the two primary alpha-chain cross-linking acceptor sites and consists of a remarkable series of internal duplications.  相似文献   
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Selective lowering of Abeta42 levels (the 42-residue isoform of the amyloid-beta peptide) with small-molecule gamma-secretase modulators (GSMs), such as some non-steroidal anti-inflammatory drugs, is a promising therapeutic approach for Alzheimer's disease. To identify the target of these agents we developed biotinylated photoactivatable GSMs. GSM photoprobes did not label the core proteins of the gamma-secretase complex, but instead labelled the beta-amyloid precursor protein (APP), APP carboxy-terminal fragments and amyloid-beta peptide in human neuroglioma H4 cells. Substrate labelling was competed by other GSMs, and labelling of an APP gamma-secretase substrate was more efficient than a Notch substrate. GSM interaction was localized to residues 28-36 of amyloid-beta, a region critical for aggregation. We also demonstrate that compounds known to interact with this region of amyloid-beta act as GSMs, and some GSMs alter the production of cell-derived amyloid-beta oligomers. Furthermore, mutation of the GSM binding site in the APP alters the sensitivity of the substrate to GSMs. These findings indicate that substrate targeting by GSMs mechanistically links two therapeutic actions: alteration in Abeta42 production and inhibition of amyloid-beta aggregation, which may synergistically reduce amyloid-beta deposition in Alzheimer's disease. These data also demonstrate the existence and feasibility of 'substrate targeting' by small-molecule effectors of proteolytic enzymes, which if generally applicable may significantly broaden the current notion of 'druggable' targets.  相似文献   
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This paper introduces a non-assembly manufacturing case with microstereolithography technology. The design and manufacturing process of a pneumatic thrust bearing is described, and a special tessellation method is developed to further improve the capability of the manufacturing system thus bigger products can also be easily manufactured. Implemented in a layer-by-layer fashion, stereolithography has been used for the rapid manufacturing of complex devices, and it avoids the expensive assembly process in the traditional manufacturing. This paper presents that microstereolithography can produce high-resolution products with intricate details, small openings, and smooth surfaces. The potential of the microstereolithograhy technique is explored for the rapid manufacturing of small and complex objects.  相似文献   
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G A Cottrell  L P Schot  G J Dockray 《Nature》1983,304(5927):638-640
Recently, there has been intense interest in the possibility that peptides might function as neurotransmitters. Despite much progress, there remains no clear-cut example in which the production of a chemically characterized peptide may be ascribed to individual identifiable neurones of proven physiological role. Invertebrate systems have proved to be particularly valuable for the study of identified neurones, including those producing peptides. We have now identified a neurone in ganglia of Helix that is associated with a peptide of the Phe-Met-Arg-Phe-NH2 (FMRFamide) group, and which influences tentacle contraction. This system offers for the first time the capacity to study peptidergic transmission in a system in which both the cell soma and the postsynaptic target may be readily and reproducibly identified.  相似文献   
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