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   629篇
  免费   29篇
  国内免费   4篇
耳鼻咽喉   4篇
儿科学   45篇
妇产科学   7篇
基础医学   66篇
口腔科学   31篇
临床医学   32篇
内科学   96篇
皮肤病学   13篇
神经病学   35篇
特种医学   97篇
外科学   66篇
综合类   65篇
预防医学   19篇
眼科学   22篇
药学   29篇
肿瘤学   35篇
  2022年   7篇
  2021年   8篇
  2020年   7篇
  2019年   6篇
  2018年   12篇
  2017年   8篇
  2016年   9篇
  2015年   22篇
  2014年   14篇
  2013年   22篇
  2012年   26篇
  2011年   38篇
  2010年   31篇
  2009年   20篇
  2008年   19篇
  2007年   31篇
  2006年   25篇
  2005年   27篇
  2004年   10篇
  2003年   12篇
  2002年   23篇
  2001年   13篇
  2000年   14篇
  1999年   18篇
  1998年   31篇
  1997年   25篇
  1996年   19篇
  1995年   16篇
  1994年   13篇
  1993年   10篇
  1992年   5篇
  1991年   3篇
  1990年   2篇
  1989年   15篇
  1988年   13篇
  1987年   16篇
  1986年   14篇
  1985年   6篇
  1984年   6篇
  1983年   8篇
  1982年   6篇
  1981年   7篇
  1980年   7篇
  1978年   3篇
  1977年   1篇
  1976年   4篇
  1975年   8篇
  1969年   1篇
  1960年   1篇
排序方式: 共有662条查询结果,搜索用时 173 毫秒
1.
2.
The purpose of this study is to show the spectrum of adjacent organ invasion and to make a brief review of hepatic alveolar hydatid disease (AHD), using CT and MR imaging. We retrospectively reviewed CT and MR images of three patients with various adjacent organ invasions surgically and histologically proven to be AHD. Local invasion to right kidney and adrenal, right hemidiaphragm and lung were detected in one patient, right adrenal in another patient and gall bladder, duodenum, gastric wall and pancreas invasion in the other. AHD may rarely extend to the gall bladder, stomach, duodenum, pancreas, right adrenal and kidney, diaphragm, pleura and lung. The extension of the disease outside the liver is usually encountered in patients with large, peripherally located masses in the advanced stage of the disease.  相似文献   
3.
We evaluated twenty renal transplant subjects at various stages of BKV nephritis (BKVN) for BKV-specific IgG and IgM antibodies using ELISA technique and BKV-DNA using PCR. They were divided as early onset (n = 7), stabilizing (n = 3), resolved (n = 8) and late onset (n = 2) BKVN. BKV-specific antibodies and BKV-DNA were simultaneously determined. The mean BKV-specific IgG level in early onset and stabilizing BKVN were 64 and 39 EIA units, and were significantly lower than 138 EIA units seen in resolved BKVN, P = 0.007, P = 0.008. The mean BKV-specific IgM levels in stabilizing BKVN was higher than resolved BKVN (130 vs 51 EIA units), P = 0.006. Mean plasma BKV loads for each group were 955,925, 5642 and 42 copies/mL of plasma, respectively. Prospective study in six BKVN cases revealed mean IgG, IgM levels and BKV-DNA at the time of diagnosis of BKVN as 39, 110 EIA units and 586,758 copies/mL of plasma, respectively. After a mean period of 5.2 months, IgG level increased to 120 EIA units (p = 0.0058) and had no detectable viral copies in circulation. Recovery from BKVN and elimination of BKV is associated with the development of BKV-specific IgG antibodies and this provides insight into the role of humoral immunity to BKV in the pathogenesis of BKVN.  相似文献   
4.
5.
Deprivation of form vision by the fitting of translucent occluders suppressed the diurnal cycling of enkephalinergic amacrine cells (the ENSLI amacrine cells), in the chicken. Daily periods of normal vision or enforcing temporal contrast using strobe lighting appeared to restore normal functioning of the ENSLI cells. These results suggest that the ENSLI cells are involved in retinal circuits that assess the quality of the visual image and control eye growth.  相似文献   
6.
7.
8.
9.
10.
Mutations in the PEX gene at Xp22.1 (phosphate-regulating gene with homologies to endopeptidases, on the X-chromosome), are responsible for X-linked hypophosphataemic rickets (HYP). Homology of PEX to the M13 family of Zn2+ metallopeptidases which include neprilysin (NEP) as prototype, has raised important questions regarding PEX function at the molecular level. The aim of this study was to analyse 99 HYP families for PEX gene mutations, and to correlate predicted changes in the protein structure with Zn2+ metallopeptidase gene function. Primers flanking 22 characterised exons were used to amplify DNA by PCR, and SSCP was then used to screen for mutations. Deletions, insertions, nonsense mutations, stop codons and splice mutations occurred in 83% of families screened for in all 22 exons, and 51% of a separate set of families screened in 17 PEX gene exons. Missense mutations in four regions of the gene were informative regarding function, with one mutation in the Zn2+-binding site predicted to alter substrate enzyme interaction and catalysis. Computer analysis of the remaining mutations predicted changes in secondary structure, N-glycosylation, protein phosphorylation and catalytic site molecular structure. The wide range of mutations that align with regions required for protease activity in NEP suggests that PEX also functions as a protease, and may act by processing factor(s) involved in bone mineral metabolism.   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