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   189798篇
  免费   2109篇
  国内免费   70篇
耳鼻咽喉   1385篇
儿科学   7182篇
妇产科学   3451篇
基础医学   18243篇
口腔科学   1770篇
临床医学   13856篇
内科学   34022篇
皮肤病学   1134篇
神经病学   17608篇
特种医学   9386篇
外科学   31158篇
综合类   2510篇
一般理论   20篇
预防医学   19001篇
眼科学   3089篇
药学   10359篇
中国医学   658篇
肿瘤学   17145篇
  2023年   115篇
  2022年   184篇
  2021年   594篇
  2020年   350篇
  2019年   474篇
  2018年   22387篇
  2017年   17684篇
  2016年   19866篇
  2015年   1302篇
  2014年   1325篇
  2013年   1472篇
  2012年   7952篇
  2011年   21968篇
  2010年   19311篇
  2009年   11995篇
  2008年   20232篇
  2007年   22490篇
  2006年   1309篇
  2005年   2877篇
  2004年   4033篇
  2003年   4893篇
  2002年   2975篇
  2001年   486篇
  2000年   611篇
  1999年   363篇
  1998年   327篇
  1997年   287篇
  1996年   163篇
  1995年   168篇
  1994年   164篇
  1993年   134篇
  1992年   168篇
  1991年   223篇
  1990年   236篇
  1989年   202篇
  1988年   168篇
  1987年   160篇
  1986年   146篇
  1985年   149篇
  1984年   133篇
  1983年   119篇
  1982年   111篇
  1981年   106篇
  1980年   112篇
  1979年   93篇
  1978年   81篇
  1977年   70篇
  1974年   76篇
  1969年   62篇
  1938年   64篇
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
71.
72.

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   
73.
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   
74.

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   
75.
76.

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   
77.

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   
78.

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   
79.

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   
80.
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