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   421篇
  免费   24篇
  2021年   10篇
  2020年   3篇
  2019年   4篇
  2018年   9篇
  2017年   5篇
  2016年   16篇
  2015年   27篇
  2014年   39篇
  2013年   39篇
  2012年   38篇
  2011年   49篇
  2010年   26篇
  2009年   21篇
  2008年   25篇
  2007年   25篇
  2006年   19篇
  2005年   13篇
  2004年   15篇
  2003年   10篇
  2002年   6篇
  2001年   3篇
  2000年   5篇
  1999年   4篇
  1998年   2篇
  1997年   2篇
  1996年   2篇
  1994年   1篇
  1993年   2篇
  1991年   2篇
  1990年   2篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   4篇
  1985年   1篇
  1984年   2篇
  1982年   4篇
  1981年   1篇
  1980年   1篇
  1977年   1篇
  1974年   1篇
  1958年   1篇
排序方式: 共有445条查询结果,搜索用时 234 毫秒
441.
442.
The sequence of a feline class I pseudogene and its comparison with class I genes from other species is presented. The gene isolated is a pseudogene because of the presence of four stop codons and two frame shift mutations in the first-and second-domain encoding exons, as well as a mutation in a splice acceptor site in the third intron. By sequence comparison with the other class I sequences determined to date, theFLA pseudogene is most closely related to theHLA-A locus products (88% nucleotide identity). The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession number M27192.  相似文献   
443.
While the incidence of Human African Trypanosomiasis (HAT) is decreasing, the control approach is shifting from active population screening by mobile teams to passive case detection in primary care centers. We conducted a systematic review of the literature between 1970 and 2011 to assess which diagnostic tools are most suitable for use in first-line health facilities in endemic countries. Our search retrieved 16 different screening and confirmation tests for HAT. The thermostable format of the Card Agglutination Test for Trypanosomiasis (CATT test) was the most appropriate screening test. Lateral flow antibody detection tests could become alternative screening tests in the near future. Confirmation of HAT diagnosis still depends on visualizing the parasite in direct microscopy. All other currently available confirmation tests are either technically too demanding and/or lack sensitivity and thus rather inappropriate for use at health center level. Novel applications of molecular tests may have potential for use at district hospital level.  相似文献   
444.
Ohne ZusammenfassungDissertation der Mathematisch-Naturwissenschaftlichen Fakultät der Freien Universität Berlin, 1957.  相似文献   
445.
Development in the osteocranium of Corydoras aeneus was studied based on 48 cleared and stained specimens and 10 series of serial sections. Development overall follows the general trends observed in siluriform development, with ossifications appearing as a response to functional demands. Early development of the skull occurs in two distinct phases. In a first phase, several new bony elements, all of dermal origin and related to feeding, appear shortly after yolk depletion (4.4 mm SL). Between 5 and 8 mm SL, developmental priorities seem to shift to size increase of the cartilaginous skull and no new bony elements appear. Finally, a second phase of osteogenesis occurs from 8 to 18 mm SL, in which all remaining dermal and perichondral bones appear. J. Morphol. 2011. © 2011 Wiley‐Liss, Inc.  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