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   25369篇
  免费   5947篇
  国内免费   127篇
耳鼻咽喉   663篇
儿科学   750篇
妇产科学   829篇
基础医学   842篇
口腔科学   2907篇
临床医学   4827篇
内科学   5724篇
皮肤病学   500篇
神经病学   2187篇
特种医学   1172篇
外科学   4223篇
综合类   139篇
现状与发展   12篇
一般理论   4篇
预防医学   3102篇
眼科学   380篇
药学   366篇
中国医学   7篇
肿瘤学   2809篇
  2024年   165篇
  2023年   1109篇
  2022年   382篇
  2021年   700篇
  2020年   1252篇
  2019年   546篇
  2018年   1375篇
  2017年   1343篇
  2016年   1546篇
  2015年   1613篇
  2014年   2054篇
  2013年   2540篇
  2012年   984篇
  2011年   938篇
  2010年   1470篇
  2009年   2036篇
  2008年   934篇
  2007年   672篇
  2006年   846篇
  2005年   641篇
  2004年   504篇
  2003年   441篇
  2002年   405篇
  2001年   498篇
  2000年   375篇
  1999年   493篇
  1998年   542篇
  1997年   519篇
  1996年   571篇
  1995年   424篇
  1994年   339篇
  1993年   285篇
  1992年   269篇
  1991年   260篇
  1990年   203篇
  1989年   227篇
  1988年   211篇
  1987年   196篇
  1986年   166篇
  1985年   156篇
  1984年   127篇
  1983年   142篇
  1982年   121篇
  1981年   98篇
  1980年   77篇
  1979年   85篇
  1978年   66篇
  1977年   78篇
  1976年   62篇
  1974年   50篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
12.
MR compatibility of Guglielmi detachable coils   总被引:6,自引:0,他引:6  
  相似文献   
13.
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   
14.
15.
16.
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   
17.
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   
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