首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   923篇
  免费   57篇
  980篇
  2022年   7篇
  2021年   28篇
  2020年   5篇
  2019年   17篇
  2018年   17篇
  2017年   17篇
  2016年   33篇
  2015年   36篇
  2014年   52篇
  2013年   40篇
  2012年   65篇
  2011年   82篇
  2010年   44篇
  2009年   37篇
  2008年   36篇
  2007年   24篇
  2006年   27篇
  2005年   32篇
  2004年   28篇
  2003年   25篇
  2002年   21篇
  2001年   27篇
  2000年   30篇
  1999年   23篇
  1998年   15篇
  1997年   7篇
  1996年   11篇
  1995年   10篇
  1994年   6篇
  1993年   7篇
  1992年   13篇
  1991年   15篇
  1990年   8篇
  1989年   6篇
  1988年   5篇
  1987年   12篇
  1986年   10篇
  1985年   4篇
  1984年   6篇
  1983年   11篇
  1982年   5篇
  1980年   9篇
  1979年   9篇
  1978年   5篇
  1976年   5篇
  1975年   4篇
  1974年   5篇
  1970年   4篇
  1966年   8篇
  1965年   3篇
排序方式: 共有980条查询结果,搜索用时 15 毫秒
91.
N1-Arylsulfonyl-3-piperazinyl indole derivatives were designed and identified as a novel class of 5-HT6 receptors ligands. All the compounds have high affinity and antagonist activity towards 5-HT6 receptor. The compound 7a (Ki = 3.4 nM, functional assay IC50 = 310 nM) shows enhanced cognitive effect when tested in NORT and Morris water maze models. Synthesis, SAR and PK profile of these novel compounds constitute the subject matter of this Letter.  相似文献   
92.
The SIBLING (small integrin-binding ligand N-linked glycoproteins) family is the major group of noncollagenous proteins in bone and dentin. These extremely acidic and highly phosphorylated extracellular proteins play critical roles in the formation of collagenous mineralized tissues. Whereas the lack of individual SIBLINGs causes significant mineralization defects in vivo, none of them led to a complete cessation of mineralization suggesting that these proteins have overlapping functions. To assess whether different SIBLINGs regulate biomineralization in a similar manner and how phosphorylation impacts their activity, we studied the effects of two SIBLINGs, dentin matrix protein 1 (DMP1) and dentin phosphophoryn (DPP), on mineral morphology and organization in vitro. Our results demonstrate distinct differences in the effects of these proteins on mineralization. We show that phosphorylation has a profound effect on the regulation of mineralization by both proteins. Specifically, both phosphorylated proteins facilitated organized mineralization of collagen fibrils and phosphorylated DMP1-induced formation of organized mineral bundles in the absence of collagen. In summary, these results indicate that the primary structure and phosphorylation uniquely determine functions of individual SIBLINGs in regulation of mineral morphology and organization.  相似文献   
93.
Bacteroides helcogenes Benno et al. 1983 is of interest because of its isolated phylogenetic location and, although it has been found in pig feces and is known to be pathogenic for pigs, occurrence of this bacterium is rare and it does not cause significant damage in intensive animal husbandry. The genome of B. helcogenes P 36-108(T) is already the fifth completed and published type strain genome from the genus Bacteroides in the family Bacteroidaceae. The 3,998,906 bp long genome with its 3,353 protein-coding and 83 RNA genes consists of one circular chromosome and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.  相似文献   
94.
Mahella australiensis Bonilla Salinas et al. 2004 is the type species of the genus Mahella, which belongs to the family Thermoanaerobacteraceae. The species is of interest because it differs from other known anaerobic spore-forming bacteria in its G+C content, and in certain phenotypic traits, such as carbon source utilization and relationship to temperature. Moreover, it has been discussed that this species might be an indigenous member of petroleum and oil reservoirs. This is the first completed genome sequence of a member of the genus Mahella and the ninth completed type strain genome sequence from the family Thermoanaerobacteraceae. The 3,135,972 bp long genome with its 2,974 protein-coding and 59 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.  相似文献   
95.
Prevotella multisaccharivorax Sakamoto et al. 2005 is a species of the large genus Prevotella, which belongs to the family Prevotellaceae. The species is of medical interest because its members are able to cause diseases in the human oral cavity such as periodontitis, root caries and others. Although 77 Prevotella genomes have already been sequenced or are targeted for sequencing, this is only the second completed genome sequence of a type strain of a species within the genus Prevotella to be published. The 3,388,644 bp long genome is assembled in three non-contiguous contigs, harbors 2,876 protein-coding and 75 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.  相似文献   
96.
Hippea maritima (Miroshnichenko et al. 1999) is the type species of the genus Hippea, which belongs to the family Desulfurellaceae within the class Deltaproteobacteria. The anaerobic, moderately thermophilic marine sulfur-reducer was first isolated from shallow-water hot vents in Matipur Harbor, Papua New Guinea. H. maritima was of interest for genome sequencing because of its isolated phylogenetic location, as a distant next neighbor of the genus Desulfurella. Strain MH(2) (T) is the first type strain from the order Desulfurellales with a completely sequenced genome. The 1,694,430 bp long linear genome with its 1,723 protein-coding and 57 RNA genes consists of one circular chromosome and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.  相似文献   
97.
98.
99.
100.
Thirty nine clinical isolates of Acinetobacter belonging to six species were tested for resistance to 20 metal ions and their ability to produce -lactamase. Fifty two percent of the strains produced -lactamase. -Lactamase producers and non-producers were almost equally distributed in the different species. A. baumannii was the predominant biotype and was found to be most resistant to metals. Resistance to mercury was prevalent in -lactamase-producing A. baumannii only. Silver resistant strains of A. baumannii produced -lactamase. Sensitivity and resistance to copper and cadium was equally distributed between -lactamase producers and non-producers. -Lactamase-producer and -non-producer strains were uniformly sensitive to cadmium except Acinetobacter genospecies 1.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号