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   175165篇
  免费   966篇
  国内免费   3篇
耳鼻咽喉   1134篇
儿科学   6619篇
妇产科学   2997篇
基础医学   16447篇
口腔科学   1558篇
临床医学   12347篇
内科学   30710篇
皮肤病学   654篇
神经病学   16402篇
特种医学   8960篇
外科学   28804篇
综合类   2308篇
一般理论   1篇
预防医学   18084篇
眼科学   2735篇
药学   9434篇
中国医学   625篇
肿瘤学   16315篇
  2021年   42篇
  2020年   22篇
  2019年   31篇
  2018年   21949篇
  2017年   17372篇
  2016年   19520篇
  2015年   907篇
  2014年   799篇
  2013年   760篇
  2012年   6938篇
  2011年   20971篇
  2010年   18808篇
  2009年   11497篇
  2008年   19462篇
  2007年   21650篇
  2006年   493篇
  2005年   2122篇
  2004年   3331篇
  2003年   4297篇
  2002年   2437篇
  2001年   260篇
  2000年   410篇
  1999年   162篇
  1998年   201篇
  1997年   202篇
  1996年   87篇
  1995年   96篇
  1994年   96篇
  1993年   59篇
  1992年   40篇
  1991年   85篇
  1990年   123篇
  1989年   75篇
  1988年   56篇
  1987年   42篇
  1986年   24篇
  1985年   35篇
  1984年   23篇
  1983年   24篇
  1982年   28篇
  1980年   41篇
  1974年   24篇
  1970年   22篇
  1969年   23篇
  1938年   61篇
  1937年   26篇
  1935年   23篇
  1934年   30篇
  1932年   59篇
  1930年   48篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Abstract Objective: To define the diagnostic accuracy of clinical examination in patients with impaired consciousness or endotracheal intubation to detect pelvic ring fractures and to identify those with severe bleeding. Methods: Included in this prospective data collection with retrolective data analysis were a consecutive series of blunt trauma victims with either a Glasgow Coma Scale ≤ 13 or tracheal intubation. Clinical examination comprised testing for stability of the iliac wings. Results: From 784 subjects (injury severity score 23.3 ± 17.4) 93 patients (11.9%) were found to have a pelvic ring fracture. Clinical instability of the pelvic ring was found in 42 patients. There was only one false positive. Fifty-two fractures could not be identified by clinical examination, including nine fractures (17%) that required surgical fracture stabilization (sensitivity of clinical examination 44.1%). Seventeen fractures (18.3%) were associated with a blood loss larger than 20% of circulating blood volume. Sixteen of those were identified by clinical instability of the pelvic ring (sensitivity 94.1%, specificity 97.0%, positive predictive value 38.1%, negative predictive value 99.9%). Conclusions: Clinical examination for stability of the pelvis in this selected group of patients missed a significant number of pelvic ring fractures including fractures that require surgical stabilization. The finding of a clinically unstable identifies most of the patients with the pelvic ring fracture being a major source of bleeding. A stable pelvis makes pelvic ring fracture as being the source of bleeding quite unlikely.  相似文献   
53.

Background  

Reports on childhood cancer survivors estimated cumulative probability of developing secondary neoplasms vary from 3,3% to 25% at 25 years from diagnosis, and the risk of developing another cancer to several times greater than in the general population.  相似文献   
54.
55.

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   
56.
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   
57.

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   
58.
59.

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   
60.

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   
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