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   13546篇
  免费   1226篇
  国内免费   32篇
耳鼻咽喉   118篇
儿科学   483篇
妇产科学   272篇
基础医学   1669篇
口腔科学   264篇
临床医学   1491篇
内科学   2617篇
皮肤病学   148篇
神经病学   1336篇
特种医学   543篇
外科学   1948篇
综合类   338篇
一般理论   18篇
预防医学   1349篇
眼科学   362篇
药学   1037篇
中国医学   10篇
肿瘤学   801篇
  2022年   133篇
  2021年   234篇
  2020年   144篇
  2019年   246篇
  2018年   298篇
  2017年   223篇
  2016年   241篇
  2015年   292篇
  2014年   368篇
  2013年   514篇
  2012年   794篇
  2011年   792篇
  2010年   431篇
  2009年   363篇
  2008年   694篇
  2007年   703篇
  2006年   697篇
  2005年   656篇
  2004年   686篇
  2003年   565篇
  2002年   587篇
  2001年   357篇
  2000年   341篇
  1999年   312篇
  1998年   160篇
  1997年   134篇
  1996年   135篇
  1995年   95篇
  1994年   118篇
  1993年   128篇
  1992年   281篇
  1991年   242篇
  1990年   203篇
  1989年   193篇
  1988年   184篇
  1987年   181篇
  1986年   171篇
  1985年   154篇
  1984年   119篇
  1983年   97篇
  1982年   80篇
  1981年   79篇
  1980年   92篇
  1979年   85篇
  1978年   81篇
  1977年   76篇
  1976年   86篇
  1974年   75篇
  1973年   94篇
  1972年   86篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Over the last 15 years photodynamic therapy (PDT) has become a viable treatment for pre-malignant and malignant disease of the oesophagus. Its initial use was in the palliation of oesophageal malignant obstruction bringing improved swallowing hence increasing nutritional intake and improving general quality of life. As the therapeutic boundaries of PDT have stretched, current studies look at the role of PDT in the treatment of pre-malignant dysplastic Barrett's epithelium and early malignancy as a curative mucosal ablative technique. As a curative treatment in early oesophageal cancer, PDT provides an alternative treatment to oesophagectomy for those more elderly or less medically fit patients.This paper reviews the uses of photodynamic therapy in oesophageal cancer with reference to the available publications on its use in the palliation of oesophageal cancer and treatment of early cancer and high grade dysplasia in Barrett's mucosa.  相似文献   
7.
Previous studies have indicated that statistically significant increases in Secretory immunoglobulin A (S‐IgA) can be achieved in as little as 5min as a result of mental stress. However, the temporal resolution of these changes is low and therefore the rate and pattern of changes during the stress task and during subsequent recovery is unclear. A within‐subjects design was used to examine levels of S‐IgA before, during and after a short (8 min) mental stress task. S‐IgA was measured from saliva samples obtained every 2 min during the entire 30‐min session. Significant increases in S‐IgA concentration were observed as early as the task instruction period, with additional increases during the stress task itself. The data also show a rapid recovery of S‐IgA, with a return to baseline levels within 6 min. Results suggest that S‐IgA changes can occur very rapidly and that the observed increases are short‐lived. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
8.
The purpose of this study was to assess 7 methods of fixation for a midtarsal osteotomy. Polyurethane foam models (N = 6) and cadaver specimens (N = 4-7) were used to examine the force generated by the different constructs of fixation. A midtarsal osteotomy was performed on each specimen in the test groups. The osteotomies were fixated either with 2 parallel 0.062-in Kirschner wires and 40-mm-long, 4-mm partially threaded, cancellous, cannulated titanium screws, an external ring fixator (frame), a frame with wires tensioned (tension), a frame with wires tensioned and compressed toward the osteotomy (tension and compression), a frame with tension, compression, and parallel Kirschner wires, or a frame with tension, compression, and two 4.0 cannulated parallel screws, respectively. Each model was fixated, and the force generated by the construct across the osteotomy was recorded via the use of pressure-sensitive film. Statistical analysis of the data in the polyurethane foam group determined that the use of frame with tension, compression, and two 4.0 parallel cannulated screws was statistically superior to 1) frame, 2) frame with tension, 3) 2 parallel Kirschner wires, 4) two 4.0 cannulated parallel screws, and 5) frame with tension and compression. A cadaver study determined that the frame with tension, compression, and 2 parallel Kirschner wires was statistically superior to 1) frame and 2) two parallel Kirschner wires. These findings suggest that there is a difference in the force generated by the type of fixation construct across a midtarsal osteotomy.  相似文献   
9.
Objectives: Heavy smokers are a segment of the smoking population who are at increased risk of smoking-related morbidity and least likely to achieve cessation. This study identifies the impact of heavy smoking on quality of life by gender and describes the subpopulation for improved targeting.Methods: South Australian representative population data (n = 3010) was used to compare the health-related quality of life status of male and female heavy smokers as assessed by the SF-36.  相似文献   
10.
Coccidiosis of chickens, caused by species of Eimeria (Protozoa, Apicomplexa), is an intestinal disease of major economic importance worldwide. In the present study, the reproductive characteristics of a precocious line (designated E. tenella Rt3+15) from Australia were investigated in chicken embryos and the implications of the findings briefly discussed.  相似文献   
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