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   5850篇
  免费   492篇
  国内免费   10篇
耳鼻咽喉   23篇
儿科学   192篇
妇产科学   163篇
基础医学   742篇
口腔科学   48篇
临床医学   683篇
内科学   1141篇
皮肤病学   51篇
神经病学   646篇
特种医学   115篇
外科学   514篇
综合类   121篇
一般理论   9篇
预防医学   1019篇
眼科学   121篇
药学   393篇
中国医学   2篇
肿瘤学   369篇
  2023年   59篇
  2022年   68篇
  2021年   141篇
  2020年   103篇
  2019年   149篇
  2018年   149篇
  2017年   119篇
  2016年   117篇
  2015年   113篇
  2014年   163篇
  2013年   277篇
  2012年   376篇
  2011年   369篇
  2010年   225篇
  2009年   158篇
  2008年   303篇
  2007年   291篇
  2006年   279篇
  2005年   302篇
  2004年   258篇
  2003年   264篇
  2002年   207篇
  2001年   127篇
  2000年   107篇
  1999年   102篇
  1998年   73篇
  1997年   48篇
  1996年   51篇
  1995年   53篇
  1994年   42篇
  1993年   44篇
  1992年   66篇
  1991年   62篇
  1990年   64篇
  1989年   72篇
  1988年   60篇
  1987年   47篇
  1986年   40篇
  1985年   59篇
  1984年   55篇
  1983年   47篇
  1982年   37篇
  1981年   39篇
  1980年   35篇
  1978年   27篇
  1977年   27篇
  1976年   30篇
  1975年   26篇
  1974年   34篇
  1966年   25篇
排序方式: 共有6352条查询结果,搜索用时 31 毫秒
1.
The present study evaluates the response comparability between 361 elderly hip fracture patients admitted from the community to seven Baltimore area hospitals between 1984 and 1986 and interviewer selected proxies on items pertaining to patients' pre-fracture health and functional status. Agreement across items ranges from very poor to good and varies with respect to the health or functional area assessed. Proxies tend to overestimate patient disability relative to the patients themselves, especially with regard to capacity to perform instrumental activities of daily living. Although proxies who report the greatest contact with patients respond most comparably to the patients, when they do disagree, proxies with the greatest patient contact tend to overestimate patient disability. The authors suggest that attention to item construction and phrasing may improve response comparability.  相似文献   
2.
Wasting protein-energy malnutrition (PEM) was induced in male C57BL/6J mice fed a low-protein diet ad libitum from 23 to 37 d of age. In comparison with a complete diet, the low-protein formulation reduced delayed hypersensitivity to sheep red blood cells (SRBCs) assessed on day 14 of feeding by measuring increased footpad thickness (mean +/- SD: 4 +/- 4% vs 22 +/- 8%, P less than 0.01), after immunization on day 9, and after challenge with SRBCs on day 13. By contrast, the low-protein diet did not affect the anti-SRBC hemagglutinin titer (8.3 +/- 2.2 vs 9.1 +/- 1.1, P greater than 0.30) despite profound reduction in numbers of splenic plasma cells secreting IgM-class anti-SRBCs (7.3 +/- 3.1 vs 49.9 +/- 23.8 x 10(-3), P less than 0.001), after immunization on day 9 and assessment on day 14. Thus, direct experimental evidence, previously altogether lacking, is provided in support of the concept, central to nutritional immunology, that acquired cell-mediated immunity is less resistant than is systemic humoral immunity to the depressive influence of pre-adolescent, wasting PEM.  相似文献   
3.
4.
5.
6.
Eighty patients who had undergone jejunoileal bypass for morbid obesity were examined by ultrasound at their routine follow-up visits to the clinic. Ultrasonographic evidence of intestinal intussusception was found in 15 patients (19%). Two of these patients were asymptomatic. Ultrasonographic findings were confirmed by operation in 6 patients (5 with intussusception, 1 negative).  相似文献   
7.
As the NHS adopts an information management approach to coordinated handling of total information resources, methods of systems analysis and design require assessment to ensure that they are appropriate. Mandatory use of Structured Systems Analysis and Design Methodology (SSADM) may be encouraging a damagingly narrow view of information systems. Research is described in which an holistic view of information systems is applied, allowing the needs of information users to play a stronger role in determining how information will be supplied to them. The techniques may also assist the training activities associated with implementing new systems.  相似文献   
8.
The health status of many people in developing countries is often dismal compared with the norms in industrialized countries. Increasingly, medical practitioners in the United States and other industrialized countries have become interested in global health issues, an interest that often takes the form of short-term international medical trips. We discuss several ethical issues associated with participation in such trips and use our experiences in developing the Children's Health International Medical Project of Seattle (CHIMPS) to outline and illustrate a set of 7 guiding principles for making these trips. CHIMPS is a resident-run, faculty-supported international medical program founded in 2002 by pediatric residents at the University of Washington in Seattle. Members of CHIMPS work with a rural community in El Salvador to support ongoing public health interventions there and provide sustainable medical care in collaboration with the community and a local nongovernmental organization. The 7 principles developed as a result of this work-mission, collaboration, education, service, teamwork, sustainability, and evaluation-can be used as a model for health practitioners as they develop or select international medical trips. The importance of partnering with the community and working within the existing medical and public health infrastructure is emphasized. Many of the challenges of doing international medical work can be overcome when efforts are guided by a few specific principles, such as those we have outlined.  相似文献   
9.
10.
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