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   211452篇
  免费   15295篇
  国内免费   749篇
耳鼻咽喉   2287篇
儿科学   5512篇
妇产科学   4339篇
基础医学   27215篇
口腔科学   4518篇
临床医学   20165篇
内科学   45054篇
皮肤病学   2778篇
神经病学   20373篇
特种医学   6975篇
外国民族医学   13篇
外科学   33193篇
综合类   3425篇
现状与发展   2篇
一般理论   292篇
预防医学   19265篇
眼科学   4402篇
药学   14449篇
  1篇
中国医学   374篇
肿瘤学   12864篇
  2023年   846篇
  2022年   1413篇
  2021年   3463篇
  2020年   2116篇
  2019年   3407篇
  2018年   3998篇
  2017年   3223篇
  2016年   3424篇
  2015年   4087篇
  2014年   6119篇
  2013年   8853篇
  2012年   13183篇
  2011年   14393篇
  2010年   8123篇
  2009年   7341篇
  2008年   13657篇
  2007年   14469篇
  2006年   13973篇
  2005年   14447篇
  2004年   13845篇
  2003年   12958篇
  2002年   12485篇
  2001年   1933篇
  2000年   1520篇
  1999年   2093篇
  1998年   2839篇
  1997年   2449篇
  1996年   2213篇
  1995年   1965篇
  1994年   1764篇
  1993年   1660篇
  1992年   1244篇
  1991年   1181篇
  1990年   1073篇
  1989年   973篇
  1988年   1028篇
  1987年   1046篇
  1986年   1017篇
  1985年   1090篇
  1984年   1488篇
  1983年   1470篇
  1982年   1821篇
  1981年   1643篇
  1980年   1558篇
  1979年   816篇
  1978年   967篇
  1977年   937篇
  1976年   835篇
  1975年   686篇
  1974年   673篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Preventing sports injury has rarely been cited as an appropriate action to respond to the obesity epidemic, and in fact a recent letter has suggested that those playing sport are as responsible for their predicament as those who are obese. This opinion piece argues that it is time for better prevention and management of sports injury to be seen as part of the complex solution to preventing obesity, rather than being a self-inflicted problem that governments should continue to ignore.  相似文献   
92.
93.
94.
OBJECTIVE: To assess the impact of activity restriction (AR) on the incidence of preterm birth in women treated for preterm labor testing negative for fetal fibronectin (fFN). STUDY DESIGN: Women who were diagnosed with preterm labor and tocolyzed with magnesium sulfate were concurrently screened with fFN for the purpose of subsequent management. Included were consenting patients with negative fFN, gestational age 23 0/7-33 6/7 weeks, cervical dilation < or =3 cm, and minimal vaginal bleeding. Patients were randomized to AR or no AR. Primary study outcome was incidence of preterm delivery and interval from randomization to delivery. RESULTS: A total of 73 women with negative fFN were randomized (36 with AR, 37 without AR). The overall preterm birth rate was 40%, with 44.4% of patients with AR and 35.1% of patients without AR delivering preterm, p=0.478. CONCLUSION: Maternal AR did not impact pregnancy outcome. The incidence of preterm birth in symptomatic women testing fFN negative was higher than previously reported.  相似文献   
95.
96.
Pryor  John 《JAMA》2006,296(19):2379
  相似文献   
97.
98.
Event-related brain potentials (ERPs) were recorded during a computerized and modified version of the Digit Span Backwards (DB) task from the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III). The modified DB version (ERP-DB task) was divided into two sections of 2, 4, 6 and 8 digits in length (Group 1) and 3, 5 and 7 digits in length (Group 2). Each trial had a study phase and a test phase. For the study phase, a series of digits was presented sequentially and aurally to 20 participants (10 for each group). For the test phase, a second series of digits was also presented sequentially and aurally that either corresponded to the reverse order of the digits in the study phase (correct condition) or had one digit in the sequence replaced by an incorrect digit (incorrect condition). The traditional DB task of the WAIS-III was also administered for comparison purposes. A prolonged positive slow wave (PSW) peaking between 450 and 750 ms was elicited to incorrect condition trials. For each participant, a derived measure was calculated from the ERP differentiation between correct and incorrect conditions. The derived measure was defined as the mean of the t-values obtained from the correct and incorrect waveform comparison, within the temporal interval that encompassed this component. The strongest statistical correlations between the derived measure and the traditional DB test scores were found at the Pz site (Group 1: r=0.79; Group 2: r=0.59). This statistical approach shows that it is possible to adequately relate an individual's performance on a traditional measure of working memory and ERP patterns. Overall, we believe that this kind of ERP approach holds promise as a technique for assessing quantitatively non-communicative patients.  相似文献   
99.
100.
I enjoyed reading the contribution by Nieminen et al.1 focusingon the predictive role for cardiovascular mortality, especiallysudden cardiac death, of the T-wave alternans (TWA) calculatedby the analytical  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