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   842篇
  免费   64篇
  国内免费   63篇
耳鼻咽喉   2篇
儿科学   47篇
妇产科学   2篇
基础医学   86篇
口腔科学   24篇
临床医学   74篇
内科学   171篇
皮肤病学   24篇
神经病学   19篇
特种医学   258篇
外科学   36篇
综合类   57篇
预防医学   29篇
眼科学   5篇
药学   102篇
肿瘤学   33篇
  2023年   1篇
  2022年   2篇
  2021年   11篇
  2020年   3篇
  2019年   2篇
  2018年   7篇
  2017年   6篇
  2016年   8篇
  2015年   11篇
  2014年   16篇
  2013年   15篇
  2012年   2篇
  2011年   6篇
  2010年   18篇
  2009年   28篇
  2008年   9篇
  2007年   40篇
  2006年   17篇
  2005年   28篇
  2004年   14篇
  2003年   12篇
  2002年   13篇
  2001年   24篇
  2000年   14篇
  1999年   23篇
  1998年   56篇
  1997年   63篇
  1996年   58篇
  1995年   57篇
  1994年   34篇
  1993年   42篇
  1992年   15篇
  1991年   20篇
  1990年   21篇
  1989年   47篇
  1988年   35篇
  1987年   32篇
  1986年   17篇
  1985年   21篇
  1984年   12篇
  1983年   7篇
  1982年   15篇
  1981年   18篇
  1980年   19篇
  1979年   12篇
  1978年   5篇
  1977年   16篇
  1976年   10篇
  1975年   7篇
排序方式: 共有969条查询结果,搜索用时 0 毫秒
91.
Biliary lithotripsy: early observations in 106 patients. Work in progress   总被引:1,自引:0,他引:1  
Burhenne  HJ; Becker  CD; Malone  DE; Rawat  B; Fache  JS 《Radiology》1989,171(2):363-367
One hundred six patients underwent extracorporeal shock wave lithotripsy for cholelithiasis. Of these, 28 patients underwent cholangiographically guided lithotripsy for bile duct stones to assist nonoperative stone removal by endoscopic or radiologic intervention. Fragmentation occurred in 20 of 28 cases (71%) with an average of two lithotripsy sessions. Hemobilia was observed in four patients (14%) for a 24-hour period. Seventy-eight of the 106 were outpatients with symptomatic cholecystolithiasis with one to five calculi who underwent cholecystographic or ultrasound-(US) guided shock wave lithotripsy as definitive therapy. US examination showed stone fragmentation in 86% of cases. With an average of 1.6 treatment sessions and 4,750 shocks, fragments were 4 mm or smaller in 46% of patients. Nine percent of patients had no fragments after an average of 10 weeks, but long-term follow-up is not yet available. Two patients developed acute pancreatitis attributable to fragment passage and one patient acute cholecystitis, likely due to cystic duct obstruction by a fragment.  相似文献   
92.
93.
94.
95.
Temporal lobes: surface MR coil phased-array imaging   总被引:1,自引:0,他引:1  
Hayes  CE; Tsuruda  JS; Mathis  CM 《Radiology》1993,189(3):918
  相似文献   
96.
97.
98.
The effects of transforming growth factor beta 3 (TGF-beta 3) on growth in semisolid cultures of enriched hematopoietic progenitors derived from normal human marrow and blood were evaluated. Conditioned media from the Mo-T cell line (MoCM) were the source of colony-stimulating factors used to optimally stimulate primitive progenitors. To assess whether a proportion of granulocyte/monocyte (GM) progenitors were prevented from cycling, all sizes of GM aggregates were evaluated from 3 to 20 days. The activity of TGF-beta 3 on the growth of erythroid burst-forming units (BFU-E) and granulocyte-macrophage colony-forming units (CFU-GM) was similar to that observed for TGF-beta 1. TGF-beta 3 (10, 100, and 1,000 pmol/liter), added initially or 72 h after initiation of culture, did not significantly affect the total number of marrow GM aggregates at 3, 7, 14, and 20 days, but TGF-beta 3 (1,000 pmol/liter), added initially, reduced the total number of blood GM aggregates. This suggests that some blood GM progenitors might be blocked from cycling but that the great majority of marrow GM progenitors are not blocked. Whether TGF-beta 3 (10, 100, and 1,000 pmol/liter) was added initially or after 72 h of stimulation by MoCM, there was a dose-dependent reduction of marrow and blood GM colony size even when the total number of colonies was unaffected. TGF-beta 3 (10, 100, and 1,000 pmol/liter), added initially or at 72 h, reduced in a dose-dependent manner the size of marrow and blood-derived BFU-E. TGF-beta 3 (1,000 pmol/liter) was more likely to reduce the total number of marrow and blood BFU-E, and this increased sensitivity of the erythroid lineage may prevent the development of this population in colonies derived from multipotential colony-forming unit-granulocyte/erythroid/monocyte (CFU-GEM). The results suggest that the main effect of TGF-beta 3 and TGF-beta 1 is to slow the rate of proliferation of hematopoietic progenitors rather than to prevent them from beginning proliferation. This results in a reduction in colony size which prevents the identification of primitive versus mature progenitor on the basis of standard criteria of colony size.  相似文献   
99.
100.
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