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   24920篇
  免费   5980篇
  国内免费   138篇
耳鼻咽喉   700篇
儿科学   713篇
妇产科学   838篇
基础医学   881篇
口腔科学   2699篇
临床医学   4504篇
内科学   5988篇
皮肤病学   494篇
神经病学   2233篇
特种医学   1062篇
外科学   4250篇
综合类   94篇
现状与发展   12篇
一般理论   2篇
预防医学   2922篇
眼科学   439篇
药学   422篇
中国医学   8篇
肿瘤学   2777篇
  2024年   165篇
  2023年   1098篇
  2022年   371篇
  2021年   655篇
  2020年   1232篇
  2019年   529篇
  2018年   1365篇
  2017年   1315篇
  2016年   1542篇
  2015年   1608篇
  2014年   2007篇
  2013年   2471篇
  2012年   876篇
  2011年   837篇
  2010年   1421篇
  2009年   2009篇
  2008年   828篇
  2007年   638篇
  2006年   772篇
  2005年   586篇
  2004年   464篇
  2003年   402篇
  2002年   370篇
  2001年   514篇
  2000年   405篇
  1999年   496篇
  1998年   549篇
  1997年   522篇
  1996年   563篇
  1995年   423篇
  1994年   333篇
  1993年   283篇
  1992年   283篇
  1991年   266篇
  1990年   246篇
  1989年   240篇
  1988年   216篇
  1987年   200篇
  1986年   196篇
  1985年   193篇
  1984年   158篇
  1983年   165篇
  1982年   130篇
  1981年   115篇
  1980年   91篇
  1979年   121篇
  1978年   97篇
  1977年   95篇
  1976年   81篇
  1974年   88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