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   21135篇
  免费   5648篇
  国内免费   126篇
耳鼻咽喉   625篇
儿科学   616篇
妇产科学   691篇
基础医学   300篇
口腔科学   2650篇
临床医学   4149篇
内科学   5019篇
皮肤病学   454篇
神经病学   1804篇
特种医学   979篇
外科学   3755篇
综合类   54篇
现状与发展   12篇
预防医学   2687篇
眼科学   319篇
药学   219篇
中国医学   6篇
肿瘤学   2570篇
  2024年   163篇
  2023年   1089篇
  2022年   354篇
  2021年   627篇
  2020年   1211篇
  2019年   479篇
  2018年   1323篇
  2017年   1281篇
  2016年   1498篇
  2015年   1554篇
  2014年   1952篇
  2013年   2357篇
  2012年   746篇
  2011年   707篇
  2010年   1342篇
  2009年   1934篇
  2008年   724篇
  2007年   480篇
  2006年   629篇
  2005年   443篇
  2004年   311篇
  2003年   276篇
  2002年   241篇
  2001年   376篇
  2000年   276篇
  1999年   382篇
  1998年   499篇
  1997年   482篇
  1996年   535篇
  1995年   386篇
  1994年   301篇
  1993年   259篇
  1992年   178篇
  1991年   157篇
  1990年   142篇
  1989年   143篇
  1988年   130篇
  1987年   123篇
  1986年   99篇
  1985年   94篇
  1984年   75篇
  1983年   90篇
  1982年   82篇
  1981年   67篇
  1980年   45篇
  1979年   32篇
  1978年   33篇
  1977年   43篇
  1976年   31篇
  1975年   27篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
MR compatibility of Guglielmi detachable coils   总被引:6,自引:0,他引:6  
  相似文献   
12.
Society often expects mothers and fathers to share equally in the perinatal grief process because the child was a common bond between them. Unfortunately, in perinatal grief, this is not always the case. The mother and the father can experience incongruent grieving and use discordant coping mechanisms. It is important to evaluate these differences to facilitate communication between the distraught parents. Improved communication can in turn facilitate the grieving process.  相似文献   
13.
14.
15.
Kathleen Rich MS  RN  CCNS 《Journal of Vascular Nursing》2002,20(4):125-35; quiz 136-7
Transcutaneous oxygen (TcPO(2)) measurements provide a noninvasive, objective determination of the oxygen level at the skin surface. This offers a means of estimating the underlying circulation and tissue oxygenation. The purpose of the pilot study was to measure the TcPO(2) value of the lower extremity of healthy men and women and of patients with peripheral arterial disease (PAD) in 4 different body and leg positions 24 hours after peripheral vascular surgery reconstruction. The specific aim was to determine if lower-extremity TcPO(2) measurements were affected by changes in extremity position in these subject populations. A convenience sample of 4 healthy health care professionals and 4 patients who had peripheral vascular reconstruction surgery 24 hours before the measurements were studied. Subjects were studied in 4 different leg and body positions: supine with legs extended, sitting with legs dependent, a 5 degrees head-up reverse Trendelenburg, and supine with legs elevated 10 in. The Radiometer TCM30 TcPO(2) monitor was used to carry out these measures. Findings revealed a statistically significant difference in TcPO(2) measurements between the 2 groups, with the healthy subjects having a significantly higher TcPO(2) measurement in all extremity positions compared with the revascularized subjects with PAD (P =.02-.05). Significant changes were noted in both the foot temperature (P =.03) and TcPO(2) measurements with extremity positions within the healthy subject group (P =.001). The foot and leg TcPO(2) measurements affect from leg and body position did not reach significance (P =.09) in the subjects with PAD. No change in foot temperature with extremity positioning (P =.42) was noted in the subjects with PAD. This pilot study provides a base in which additional research will be performed with TcPO(2) measurements in both the healthy and revascularized person.  相似文献   
16.
This study evaluates the potential for endothelial seeding of a collagen-impregnated Dacron graft with or without surface modifiers (fibronectin, heparin) to attach and retain these cells during flow. Human umbilical endothelial cells were harvested, cultured, labeled with Indium111-oxine and seeded onto 30 mm X 4 mm diameter grafts. Six graft surfaces were studied: 1) a collagen-impregnated Dacron graft, HemashieldR (C); 2) C + fibronectin (C + F); 3) C + heparin (C + H); 4) C + F + H; 5) HytrelR + F (Hyt + F); and 6) Hyt + F + H. Radioactive loss determined the percentage attachment and then percentage retention of labeled inoculum after a one-hour in vitro perfusion. Scanning electron and light microscopy demonstrated the endothelium on the graft surface following perfusion. Fibronectin-coated grafts had a significantly higher percentage attachment than those without fibronectin (ANOVA, P less than 0.05). However, the percentage retention following perfusion was similar for all Dacron grafts and statistically inferior to the HytrelR grafts studied (ANOVA, P less than 0.05). SEM evaluation of the C + F + H graft surface was qualitatively the most impressive Dacron surface for seeding, yet was inferior to the HytrelR graft. We conclude that fibronectin benefits the initial attachment of endothelium to collagen-coated Dacron rivaling the HytrelR surface. Fibronectin does not improve percentage retention of the HemashieldR surface during perfusion, therefore, some of its initial benefit is lost.  相似文献   
17.
18.
19.
20.
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