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   218197篇
  免费   5549篇
  国内免费   2984篇
耳鼻咽喉   1587篇
儿科学   7063篇
妇产科学   3331篇
基础医学   21260篇
口腔科学   2137篇
临床医学   17124篇
内科学   37468篇
皮肤病学   1537篇
神经病学   18731篇
特种医学   11050篇
外国民族医学   15篇
外科学   33116篇
综合类   9839篇
现状与发展   7篇
一般理论   4篇
预防医学   21134篇
眼科学   3724篇
药学   14232篇
  28篇
中国医学   3798篇
肿瘤学   19545篇
  2024年   218篇
  2023年   729篇
  2022年   1718篇
  2021年   2160篇
  2020年   1497篇
  2019年   1508篇
  2018年   23346篇
  2017年   18729篇
  2016年   20984篇
  2015年   3123篇
  2014年   3387篇
  2013年   3340篇
  2012年   10438篇
  2011年   24481篇
  2010年   21253篇
  2009年   13464篇
  2008年   21739篇
  2007年   23967篇
  2006年   2716篇
  2005年   4141篇
  2004年   4965篇
  2003年   6258篇
  2002年   4128篇
  2001年   1619篇
  2000年   1405篇
  1999年   891篇
  1998年   638篇
  1997年   642篇
  1996年   397篇
  1995年   346篇
  1994年   328篇
  1993年   209篇
  1992年   196篇
  1991年   232篇
  1990年   255篇
  1989年   183篇
  1988年   135篇
  1987年   105篇
  1986年   94篇
  1985年   73篇
  1984年   44篇
  1983年   29篇
  1982年   37篇
  1980年   53篇
  1969年   24篇
  1938年   60篇
  1937年   25篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
42.

Background  

It is well known that physicians' night-call duty may cause impaired performance and adverse effects on subjective health, but there is limited knowledge about effects on sleep duration and recovery time. In recent years occupational stress and impaired well-being among anaesthesiologists have been frequently reported for in the scientific literature. Given their main focus on handling patients with life-threatening conditions, when on call, one might expect sleep and recovery to be negatively affected by work, especially in this specialist group. The aim of the present study was to examine whether a 16-hour night-call schedule allowed for sufficient recovery in anaesthesiologists compared with other physician specialists handling less life-threatening conditions, when on call.  相似文献   
43.
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   
44.

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   
45.
46.

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   
47.

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   
48.

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   
49.

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   
50.
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   
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