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   207469篇
  免费   2478篇
  国内免费   132篇
耳鼻咽喉   1376篇
儿科学   7106篇
妇产科学   3416篇
基础医学   20838篇
口腔科学   2536篇
临床医学   14530篇
内科学   38833篇
皮肤病学   1396篇
神经病学   18817篇
特种医学   10071篇
外科学   33977篇
综合类   2443篇
一般理论   1篇
预防医学   19165篇
眼科学   3325篇
药学   11762篇
中国医学   689篇
肿瘤学   19798篇
  2022年   337篇
  2021年   610篇
  2020年   300篇
  2019年   419篇
  2018年   22366篇
  2017年   17725篇
  2016年   19903篇
  2015年   1400篇
  2014年   1478篇
  2013年   1588篇
  2012年   8249篇
  2011年   22377篇
  2010年   19534篇
  2009年   12207篇
  2008年   20714篇
  2007年   23011篇
  2006年   2015篇
  2005年   3627篇
  2004年   4704篇
  2003年   5761篇
  2002年   3984篇
  2001年   1693篇
  2000年   1841篇
  1999年   1405篇
  1998年   663篇
  1997年   537篇
  1996年   393篇
  1995年   358篇
  1994年   334篇
  1993年   288篇
  1992年   944篇
  1991年   891篇
  1990年   854篇
  1989年   817篇
  1988年   731篇
  1987年   724篇
  1986年   626篇
  1985年   600篇
  1984年   384篇
  1983年   328篇
  1982年   183篇
  1980年   162篇
  1979年   246篇
  1978年   191篇
  1975年   159篇
  1974年   174篇
  1973年   170篇
  1970年   170篇
  1969年   174篇
  1968年   164篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Associations between street connectivity and active transportation   总被引:1,自引:0,他引:1  

Background  

Past studies of associations between measures of the built environment, particularly street connectivity, and active transportation (AT) or leisure walking/bicycling have largely failed to account for spatial autocorrelation of connectivity variables and have seldom examined both the propensity for AT and its duration in a coherent fashion. Such efforts could improve our understanding of the spatial and behavioral aspects of AT. We analyzed spatially identified data from Los Angeles and San Diego Counties collected as part of the 2001 California Health Interview Survey.  相似文献   
52.

Objective  

To test the effects of the use of a collapsible, portable chair (chair B), as opposed to a ‘standard’ chair (chair A), on the outcome of the timed “Up and Go” (TUG) test.  相似文献   
53.
54.

Background  

Exercise has been recommended for improving global-well being in adults with fibromyalgia. However, no meta-analysis has determined the effects of exercise on global well-being using a single instrument and when analyzed separately according to intention-to-treat and per-protocol analyses. The purpose of this study was to fill that gap.  相似文献   
55.

Background  

Due to marginalization, trafficking violence, conflicts with the police and organic and social psychological problems associated with the drug, crack is one of the most devastating drugs currently in use. However, there is evidence that some users manage to stay alive and active while using crack cocaine for many years, despite the numerous adversities and risks involved with this behavior. In this context, the aim of the present study was to identify the strategies and tactics developed by crack users to deal with the risks associated with the culture of use by examining the survival strategies employed by long-term users.  相似文献   
56.

Background  

Malaria, caused by the parasite Plasmodium falciparum, is a significant source of morbidity and mortality in southern Zambia. In the Mapanza Chiefdom, where transmission is seasonal, Anopheles arabiensis is the dominant malaria vector. The ability to predict larval habitats can help focus control measures.  相似文献   
57.

Background  

Climate change is taking a toll on human health, and some leaders in the public health community have urged their colleagues to give voice to its health implications. Previous research has shown that Americans are only dimly aware of the health implications of climate change, yet the literature on issue framing suggests that providing a novel frame - such as human health - may be potentially useful in enhancing public engagement. We conducted an exploratory study in the United States of people's reactions to a public health-framed short essay on climate change.  相似文献   
58.
Research on physical activity (PA) by level of acculturation in Hispanic children is limited and findings have been mixed. We examined PA participation by primary language used with parents in a representative sample of 4th, 8th, and 11th grade Texas public school students. Mixed-effects regression models were conducted using cross-sectional data from the 2004–2005 School Physical Activity and Nutrition Study (n = 22,049). Self-reported PA was compared among three language-ethnic groups: Spanish-Hispanic (SH) (referent); English-Hispanic (EH); and English-Other (EO). EH and/or EO girls were generally between 1.25 and 2.58 [OR] times more likely to participate in PA across grade levels, with the largest differences found for school sports in 8th grade girls. EH and EO 8th grade boys were 1.71 (CI: 1.40, 2.10) and 2.06 (CI: 1.68, 2.51) times, respectively, more likely to participate in school sports. Findings indicate important disparities in Spanish-speaking Hispanic children’s PA participation.  相似文献   
59.

Introduction  

Planning human resources for health (HRH) is a complex process for policy-makers and, as a result, many countries worldwide swing from surplus to shortage. In-depth case studies can help appraising the challenges encountered and the solutions implemented. This paper has two objectives: to identify the key challenges in HRH planning in Belgium and to formulate recommendations for an effective HRH planning, on the basis of the Belgian case study and lessons drawn from an international benchmarking.  相似文献   
60.

Objective  

The aim of the project was to assess the effectiveness and safety of weekly epoetin-beta (EB) in patients with gastrointestinal cancer (GIC) subjected to concomitant chemoradiotherapy (CCTRT).  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