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   215862篇
  免费   15708篇
  国内免费   754篇
耳鼻咽喉   2326篇
儿科学   5644篇
妇产科学   4439篇
基础医学   27797篇
口腔科学   4689篇
临床医学   20525篇
内科学   45911篇
皮肤病学   2801篇
神经病学   20642篇
特种医学   7110篇
外国民族医学   27篇
外科学   33647篇
综合类   3512篇
现状与发展   2篇
一般理论   297篇
预防医学   20388篇
眼科学   4421篇
药学   14645篇
  1篇
中国医学   375篇
肿瘤学   13125篇
  2023年   868篇
  2022年   1427篇
  2021年   3519篇
  2020年   2166篇
  2019年   3452篇
  2018年   4058篇
  2017年   3286篇
  2016年   3457篇
  2015年   4141篇
  2014年   6209篇
  2013年   8974篇
  2012年   13327篇
  2011年   14504篇
  2010年   8205篇
  2009年   7387篇
  2008年   13776篇
  2007年   14604篇
  2006年   14107篇
  2005年   14584篇
  2004年   13963篇
  2003年   13056篇
  2002年   12580篇
  2001年   2031篇
  2000年   1639篇
  1999年   2167篇
  1998年   2889篇
  1997年   2473篇
  1996年   2300篇
  1995年   2094篇
  1994年   1888篇
  1993年   1786篇
  1992年   1439篇
  1991年   1360篇
  1990年   1230篇
  1989年   1079篇
  1988年   1148篇
  1987年   1145篇
  1986年   1124篇
  1985年   1209篇
  1984年   1588篇
  1983年   1553篇
  1982年   1875篇
  1981年   1693篇
  1980年   1599篇
  1979年   888篇
  1978年   1023篇
  1977年   963篇
  1976年   879篇
  1975年   726篇
  1974年   735篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
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   
83.
84.
85.
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   
86.
87.
Pryor  John 《JAMA》2006,296(19):2379
  相似文献   
88.
89.
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   
90.
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