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31.
The ubiquitin–proteasome pathway of protein degradation is one of the major mechanisms that are involved in the maintenance of the proper levels of cellular proteins. The regulation of proteasomal degradation thus ensures proper cell functions. The family of proteins containing ubiquitin-like (UbL) and ubiquitin-associated (UBA) domains has been implicated in proteasomal degradation. UbL–UBA domain containing proteins associate with substrates destined for degradation as well as with subunits of the proteasome, thus regulating the proper turnover of proteins.  相似文献   
32.
An international workshop on urban meteorology: observation and modeling, was jointly held by the Institute of Urban Meteorology (China) and the National Center for Atmospheric Research (US) in Beijing, October, 2004. The workshop was inten ded to share recent progress in urban meteorological research, discuss issues re lated to research and development priorities faced by diverse Chinese institutio ns, and explore collaboration opportunities between Chinese and US research inst itutions. This article summarizes the major issues discussed at the workshop, in cluding observation on urban boundary layer, urban landuse modeling, socioecon omic impacts of weather and climates, and air quality in urban environment. It i ncludes recommendations for future urban meteorology observational and modeling research, and potential collaborative opportunities between China and US.  相似文献   
33.
The objective of this paper is to introduce three semi-automated approaches for ontology mapping using relatedness analysis techniques. In the architecture, engineering, and construction (AEC) industry, there exist a number of ontological standards to describe the semantics of building models. Although the standards share similar scopes of interest, the task of comparing and mapping concepts among standards is challenging due to their differences in terminologies and perspectives. Ontology mapping is therefore necessary to achieve information interoperability, which allows two or more information sources to exchange data and to re-use the data for further purposes. The attribute-based approach, corpus-based approach, and name-based approach presented in this paper adopt the statistical relatedness analysis techniques to discover related concepts from heterogeneous ontologies. A pilot study is conducted on IFC and CIS/2 ontologies to evaluate the approaches. Preliminary results show that the attribute-based approach outperforms the other two approaches in terms of precision and F-measure.  相似文献   
34.
应用有限元法研究了剪切面边界条件对正交金属切削中工件表面层加工硬化深度的影响。有限元分析结果表明,剪切面法向应力分布对表面层硬化深度无显著影响,剪切面长度是影响硬化深度的主要因素。  相似文献   
35.
Psychiatric illness, such as affective disorders, anxiety disorders and schizophrenia, exerts exceptional personal burden on affected individuals. Although not physically noticeable, these disorders cost enormously on ones’ family and society. Currently pharma-ceutical and psychological treatments are generally accepted as effective for psychiatric disorders, while the exact mechanisms underlying the treatment efficacy, etiology and neurobiology of the disorders remain elusive. In the past decade, "neurogenic hy-pothesis" emerged as an attempt to explain the nature of psychiatric illness. The origination of the hypothesis is based on several pre-clinical and clinical observations. First, stress, which is a common risk factor of the disorders, was found to suppress neurogenesis; second, treatment for the illnesses like antidepressants and antipsychotics were shown to improve neurogenesis and behavioral deficits simultaneously; and third, the therapeutic effect of antidepressants was abolished in animal models when neuro-genesis was blocked. Increasing efforts were invested to determine whether neurogenesis is a key to the understanding and treatment of psychiatric disorders, although contrasting results are also found and thus the importance of neurogenesis remains a matter of debate. The present chapter will discuss the recent findings about the involvement of neurogenesis in major depression, anxiety disorders and schizophrenia, and whether neurogenesis would be a potential target for development of the treatment in the future.  相似文献   
36.
There has recently been great interest in ablative photodecomposition(APD), notably in pulsed UV laser treatment on polymers, for modification of physical and chemical properties, such as dyeability, printability, adhesion, Iuster and many more. Very little attention was focused, however, on the property of wetting behaviour,which is one of the most fundamental properties in affecting polymer science. Poly(ethylene terephthalate) (PET) fibers drawn to two different draw ratios and under two temperatures, and three white knitted polyester fabrics made of 100% PET fibre were used to investigate their wetting behaviour due to excimer laser treatment.Experiments like water contact angle measurement, vertical drop test and moisture regain were conducted upon samples and all results give the same conclusion that laser treatment increases the hydrophobicity of all samples tested. Scanning electron microscope (SEM) observation reveals how the morphological modification of polymers by laser treatment is correlate  相似文献   
37.
Summary Mice bearing L1210 leukemia did not show impaired humoral or cellular immune response to antigenic stimulation during the early stage of the tumor, and a depressed response was noted only in the terminal stage. L1210 cells were shown to suppress inflammatory reaction in vivo.Supported in part by USPHS research grant No.5-01-RR05-352-12, and by theIndependent Order of Foresters, San Bernardino District 3208. We acknowledge the valuable assistance ofJudith Johnson andJames Tan in this project. Histopathological examination byDick H. Koobs is appreciated.  相似文献   
38.
39.
Morphological revertants of avian sarcoma virus transformed vole cells contain the sarcoma gene product (pp60src) in an enzymatically active form, suggesting that the presence of pp60src protein kinase activity is infussicient to induce morphological transformation. Structural analyses of pp60src from infected vole cell clones suggest that in one of the revertant clones on alteration in pp60src may be responsible for morphological reversion while in a second clone, reversion may result from an alteration in a cell gene product with which pp60src must interact. As these morphological revertant cells are tumorigenic, different cell components are required to interact with pp60src to facilitate the two events.  相似文献   
40.
全球纳米技术研究文献计量分析   总被引:1,自引:0,他引:1  
本研究采用文本挖掘技术,从在全球公开的纳米科学和技术研究文献数据库(SCI/SSCI 数据
库)中提取技术情报。在SCI/SSCI数据库中利用纳米科学和技术领域的300多个术语进行相关文献的检
索;利用摘要共现词汇的自相关图来揭示的技术核心领域;通过词汇间的互相关图来揭示因共现而发生
关系的词汇的技术核心领域;采用因子矩阵进一步量化研究机构之间、国家之间的关系强度,并对图中
揭示的合作出版网络给予确证。  相似文献   
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