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   28953篇
  免费   6167篇
  国内免费   139篇
耳鼻咽喉   742篇
儿科学   881篇
妇产科学   861篇
基础医学   1240篇
口腔科学   2895篇
临床医学   4914篇
内科学   6602篇
皮肤病学   548篇
神经病学   2598篇
特种医学   1390篇
外国民族医学   1篇
外科学   4804篇
综合类   161篇
现状与发展   12篇
一般理论   2篇
预防医学   3463篇
眼科学   445篇
药学   691篇
中国医学   9篇
肿瘤学   3000篇
  2024年   168篇
  2023年   1124篇
  2022年   396篇
  2021年   710篇
  2020年   1270篇
  2019年   584篇
  2018年   1454篇
  2017年   1372篇
  2016年   1609篇
  2015年   1683篇
  2014年   2094篇
  2013年   2624篇
  2012年   1133篇
  2011年   1114篇
  2010年   1581篇
  2009年   2159篇
  2008年   1080篇
  2007年   830篇
  2006年   989篇
  2005年   804篇
  2004年   606篇
  2003年   558篇
  2002年   512篇
  2001年   657篇
  2000年   552篇
  1999年   570篇
  1998年   568篇
  1997年   542篇
  1996年   592篇
  1995年   431篇
  1994年   361篇
  1993年   318篇
  1992年   320篇
  1991年   308篇
  1990年   301篇
  1989年   290篇
  1988年   245篇
  1987年   265篇
  1986年   226篇
  1985年   260篇
  1984年   184篇
  1983年   194篇
  1982年   137篇
  1981年   133篇
  1980年   106篇
  1979年   137篇
  1978年   104篇
  1977年   99篇
  1975年   83篇
  1974年   84篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
14.
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   
15.
16.
17.
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   
18.
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   
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