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   170篇
  免费   16篇
  186篇
  2022年   1篇
  2020年   1篇
  2019年   1篇
  2018年   5篇
  2016年   2篇
  2015年   12篇
  2014年   7篇
  2013年   6篇
  2012年   14篇
  2011年   6篇
  2010年   2篇
  2009年   4篇
  2008年   6篇
  2007年   10篇
  2006年   5篇
  2005年   6篇
  2004年   7篇
  2003年   4篇
  2002年   11篇
  2001年   5篇
  2000年   7篇
  1999年   4篇
  1997年   2篇
  1992年   2篇
  1990年   1篇
  1989年   3篇
  1988年   6篇
  1987年   3篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1979年   2篇
  1978年   2篇
  1977年   2篇
  1976年   3篇
  1975年   5篇
  1974年   2篇
  1973年   5篇
  1972年   1篇
  1971年   3篇
  1970年   6篇
  1968年   1篇
  1967年   1篇
  1954年   1篇
  1952年   1篇
  1946年   1篇
  1942年   1篇
排序方式: 共有186条查询结果,搜索用时 12 毫秒
111.
112.
113.
114.
115.
116.
Monoclonal antibodies were produced against gonococcal protein III. Antibodies of two different specificities were obtained. One reacted with all Neisseria species tested (N. gonorrhoeae, N. meningitidis and five non-pathogenic species), whereas the other was specific for Neisseria gonorrhoeae and may provide the basis for improved diagnostic reagents.  相似文献   
117.
118.
Recently discovered hydrothermal vent fields on the East Scotia Ridge (ESR, 56–60°S, 30°W), Southern Ocean, and the South West Indian Ridge (SWIR, 37°S 49°E), Indian Ocean, host two closely related new species of peltospirid gastropods. Morphological and molecular (mitochondrial cytochrome c oxidase subunit I, COI) characterization justify the erection of G igantopelta gen. nov. within the Peltospiroidae with two new species, G igantopelta chessoia sp. nov. from ESR and G igantopelta aegis sp. nov. from SWIR. They attain an extremely large size for the clade Neomphalina, reaching 45.7 mm in shell diameter. The oesophageal gland of both species is markedly enlarged. Gigantopelta aegis has a thick sulphide coating on both the shell and the operculum of unknown function. The analysis of a 579‐bp fragment of the COI gene resulted in 19–28% pairwise distance between Gigantopelta and six other genera in Peltospiridae, whereas the range amongst those six genera was 12–28%. The COI divergence between the two newly described species of Gigantopelta was 4.43%. Population genetics analyses using COI (370 bp) of 30 individuals of each species confirmed their genetic isolation and indicate recent rapid demographic expansion in both species. © 2015 The Linnean Society of London  相似文献   
119.
Since the first animal genomes were completely sequenced ten years ago, evolutionary biologists have attempted to use the encoded information to reconstruct different aspects of the earliest stages of animal evolution. One of the most important uses of genome sequences is to understand relationships between animal phyla. Despite the wealth of data available, ranging from primary sequence data to gene and genome structures, our lack of understanding of the modes of evolution of genomic characters means that using these data is fraught with potential difficulties, leading to errors in phylogeny reconstruction. Improved understanding of how different character types evolve, the use of this knowledge to develop more accurate models of evolution, and denser taxonomic sampling, are now minimizing the sources of error. The wealth of genomic data now being produced promises that a well-resolved tree of the animal phyla will be available in the near future.  相似文献   
120.
Over the past 10 years, increasing evidence has accumulated that heterogeneity is a feature of hematopoietic stem cell (HSC) proliferation, self-renewal, and differentiation based on examination of these properties at a clonal level. The heterogeneous behavior of HSCs reflects the operation of a complex interplay of intrinsic and extrinsic variables. In this review, we discuss key findings from the last 5 years that reveal new insights into the mechanisms involved.  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