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   1158280篇
  免费   92701篇
  国内免费   13616篇
耳鼻咽喉   14672篇
儿科学   36673篇
妇产科学   29819篇
基础医学   160074篇
口腔科学   30550篇
临床医学   110249篇
内科学   213522篇
皮肤病学   24800篇
神经病学   85524篇
特种医学   44528篇
外国民族医学   373篇
外科学   166210篇
综合类   59256篇
现状与发展   49篇
一般理论   394篇
预防医学   91743篇
眼科学   26187篇
药学   89211篇
  192篇
中国医学   14617篇
肿瘤学   65954篇
  2021年   14525篇
  2020年   10555篇
  2019年   11899篇
  2018年   15608篇
  2017年   13385篇
  2016年   14208篇
  2015年   18315篇
  2014年   23829篇
  2013年   31819篇
  2012年   43137篇
  2011年   46031篇
  2010年   30013篇
  2009年   27083篇
  2008年   39537篇
  2007年   40761篇
  2006年   40617篇
  2005年   37817篇
  2004年   34692篇
  2003年   33235篇
  2002年   31298篇
  2001年   50300篇
  2000年   50615篇
  1999年   42236篇
  1998年   12322篇
  1997年   11184篇
  1996年   11020篇
  1995年   10550篇
  1994年   9686篇
  1993年   8852篇
  1992年   32625篇
  1991年   31765篇
  1990年   31283篇
  1989年   30089篇
  1988年   27346篇
  1987年   27501篇
  1986年   25563篇
  1985年   24702篇
  1984年   18451篇
  1983年   15552篇
  1982年   9312篇
  1979年   16897篇
  1978年   12232篇
  1977年   10331篇
  1976年   9770篇
  1975年   10188篇
  1974年   12336篇
  1973年   11870篇
  1972年   10893篇
  1971年   10120篇
  1970年   9384篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
良性前列腺增生(BPH)是老年男性常见的泌尿系统疾病,其发病与前列腺慢性炎症之间存在显著相关。感染因子、尿液返流、代谢综合征、衰老过程和自身免疫应答在内的几种刺激,通过相应分子途径引起前列腺免疫细胞的组织定位和组成成分发生广泛改变,从而导致免疫系统失调,之后引发的组织损伤和缓慢愈合,导致了BPH发生和进展。本文通过总结良性前列腺增生与前列腺慢性炎症的相关性的临床研究结果,前列腺免疫细胞在病理生理机制层面与前两者之间的内在联系,以及抗炎药物对BPH-LUTS的干预作用,以其为BPH-LUTS的药物研发提供参考。  相似文献   
23.
24.
25.
26.

Objective

To examine whether a healthy weight intervention embedded in the Parents as Teachers (PAT) home visiting program, which was previously found to improve mothers’ body mass index (BMI) and obesity-related behaviors, changed the BMI of preschool children or maternal feeding practices.

Methods

This stratified randomized trial included preschool-aged children at risk for overweight whose mothers were overweight or had obesity (n?=?179). The Healthy Eating and Active Living Taught at Home (HEALTH) intervention was based on the Diabetes Prevention Program. Differences were examined using repeated-measures mixed-ANOVA models.

Results

Compared with PAT usual care, the HEALTH intervention had no effect on children's BMI or maternal feeding practices. However, combined analyses showed that children's BMI percentile decreased (P??=?.007), BMI z-scores were maintained (P??=?.19), and 3 of 8 feeding practices improved over time (P < .05).

Conclusions and Implications

Additional research is needed to assess the effectiveness of PAT to prevent preschool-age obesity using rigorous designs (eg, group-randomized trials) and to identify its active components. HEALTH is ready to be scaled up to prevent maternal weight gain through embedding within the national PAT program.  相似文献   
27.
28.

Objectives

Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.

Methods

Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.

Results

A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.

Conclusions

Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight.  相似文献   
29.
30.
We report two British cases of liver abscess, due to Klebsiella pneumoniae and associated with synchronous infection elsewhere, which required liver resection for definitive treatment. They illustrate the geographic spread of aggressive K pneumoniae liver infection and demonstrate the importance of early aggressive treatment.  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