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   456篇
  免费   22篇
  国内免费   4篇
耳鼻咽喉   3篇
儿科学   37篇
妇产科学   5篇
基础医学   34篇
口腔科学   10篇
临床医学   46篇
内科学   78篇
皮肤病学   6篇
神经病学   11篇
特种医学   89篇
外科学   34篇
综合类   61篇
预防医学   17篇
眼科学   11篇
药学   17篇
肿瘤学   23篇
  2023年   1篇
  2022年   8篇
  2021年   5篇
  2020年   5篇
  2019年   2篇
  2018年   8篇
  2017年   7篇
  2016年   7篇
  2015年   16篇
  2014年   5篇
  2013年   8篇
  2012年   13篇
  2011年   17篇
  2010年   22篇
  2009年   15篇
  2008年   11篇
  2007年   13篇
  2006年   15篇
  2005年   18篇
  2004年   6篇
  2003年   7篇
  2002年   14篇
  2001年   13篇
  2000年   7篇
  1999年   13篇
  1998年   29篇
  1997年   24篇
  1996年   21篇
  1995年   16篇
  1994年   12篇
  1993年   9篇
  1992年   5篇
  1991年   2篇
  1990年   3篇
  1989年   16篇
  1988年   15篇
  1987年   16篇
  1986年   12篇
  1985年   5篇
  1984年   5篇
  1983年   7篇
  1982年   5篇
  1981年   5篇
  1980年   5篇
  1978年   1篇
  1977年   1篇
  1976年   3篇
  1975年   8篇
  1969年   1篇
排序方式: 共有482条查询结果,搜索用时 0 毫秒
1.
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   
2.
3.
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   
4.
5.
6.
7.
8.
The present studies compared the regulation of the neurotrophin ligands and receptors by estrogen in young adult and reproductively senescent rats. Both groups of animals were ovariectomized and replaced with 17beta-estradiol or placebo pellets for 4 weeks. Protein expression of specific neurotrophins and their receptors were measured in the olfactory bulb and its basal forebrain afferent, the horizontal limb of the diagonal band of Broca (hlDBB). Young-adult rats responded to estrogen with an increase in the expression of brain-derived neurotrophic factor (BDNF) in the olfactory bulb and hlDBB, as well as bulbar trkA and trkB receptors. Older rats did not respond to estrogen in this manner. Additionally, estrogen treatment decreased the expression of the universal neurotrophin receptor p75 in young adult animals, but increased expression of this receptor in reproductively senescent rats. The latter group, however, had significantly greater estrogen receptor alpha (ERalpha) expression in the olfactory bulb as compared to their younger counterparts, but very low expression of the steroid receptor coactivator, SRC-1. Changes in the proportion or ratio of steroid receptor/coactivator systems in the aging forebrain may contribute to the refractory response to estrogen in the reproductively senescent animals.  相似文献   
9.
10.
Two lines deriving from the same rabbit stock were selected for 8 generations for high (H) or low (L) locomotor activity score in the open field (OFS). The divergent selection was most effective up to the 3rd generation in the H line and up to the 4th generation in the L line. In further generations a decrease of OFS in the H line and a floor effect (OFS = 0) in the L line were observed. The mean OFS increased significantly in consecutive trials in the H line, whereas this increase was non-significant in the L line. There was a negative and very high correlation between the latency to enter the open field and the OFS (–0.95 and –0.98 for the H and L line, respectively). The realized heritability of the OFS was 0.46 and 0.23 in generations 0–3 within the L and H line, respectively, and 0.44 and –0.06 in generations 0–8. As calculated on the basis of divergent selection, the heritability was 0.31 and 0.15 for generations 0–3 and 0–8, respectively. The L rabbits were heavier shortly before (4th wk, P < 0.001) and after (8th wk, P < 0.01) weaning, than those of the H line, whereas the H rabbits grew faster (P < 0.05) between the 4th and 20th wk of age. There was a tendency for decreasing weight gains in consecutive generations. Generally, a lower percentage of H females delivered litters than those of the L line, but this was due to a very low percentage of such females in the 3rd and 6th generations. It can be assumed that H and L lines represent different, i.e., active and passive, coping strategies. These lines of rabbits offer increased possibilities for physiologically and ethologically oriented studies, e.g., on the welfare of caged animals.  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