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   45393篇
  免费   2778篇
  国内免费   185篇
耳鼻咽喉   478篇
儿科学   1395篇
妇产科学   1290篇
基础医学   5982篇
口腔科学   754篇
临床医学   6789篇
内科学   8859篇
皮肤病学   728篇
神经病学   4423篇
特种医学   885篇
外科学   4719篇
综合类   486篇
一般理论   57篇
预防医学   5129篇
眼科学   545篇
药学   2633篇
  1篇
中国医学   96篇
肿瘤学   3107篇
  2023年   274篇
  2022年   590篇
  2021年   1136篇
  2020年   650篇
  2019年   1097篇
  2018年   1227篇
  2017年   843篇
  2016年   926篇
  2015年   1165篇
  2014年   1573篇
  2013年   2313篇
  2012年   3443篇
  2011年   3585篇
  2010年   1928篇
  2009年   1627篇
  2008年   3151篇
  2007年   3202篇
  2006年   3132篇
  2005年   2934篇
  2004年   2786篇
  2003年   2654篇
  2002年   2408篇
  2001年   273篇
  2000年   193篇
  1999年   342篇
  1998年   466篇
  1997年   398篇
  1996年   360篇
  1995年   309篇
  1994年   292篇
  1993年   277篇
  1992年   181篇
  1991年   153篇
  1990年   148篇
  1989年   147篇
  1988年   115篇
  1987年   118篇
  1986年   95篇
  1985年   121篇
  1984年   165篇
  1983年   173篇
  1982年   208篇
  1981年   178篇
  1980年   167篇
  1979年   98篇
  1978年   76篇
  1977年   86篇
  1976年   66篇
  1975年   57篇
  1974年   73篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
The use of N-acetylcysteine has increased in the prevention of radiographic contrast induced nephrotoxicity. Many nurses need to be aware of the proper administration and action of this prophylactic agent. This article discusses the research behind the use of N-acetylcysteine and the protocol for administration to prevent radiographic contrast-induced nephrotoxicity.  相似文献   
32.
33.
34.
The PFA-100 is a relatively new laboratory instrument, first described in 1995. There have since been numerous studies assessing its utility as a screening tool for platelet dysfunction and/or von Willebrand's disease (VWD). The PFA-100 displays variable sensitivity to different types of platelet disorders, as well as to antiplatelet medication (e.g. aspirin), with similar caveats for monitoring of primary haemostasis-promoting therapies in platelet dysfunction. There is therefore considerable uncertainty regarding its utility within this context, and we have accordingly performed an audit of usage among participants of the Royal College of Pathologists of Australasia Quality Assurance Program. Of 105 laboratories surveyed, 40 responded that they performed platelet function testing, with 26 (65%) further indicating they utilized the PFA-100. We report a wide variety of laboratory usage among these users, including numbers of tests performed [annual median (range) = 270 (15-6000)], sources of requests (clinical sources and localities), testing criteria and follow-up action. Most tests were completed within 4 h of collection, as recommended by the manufacturer, and most tests were performed as a replacement, or as a preliminary screen of platelet function (i.e. classical aggregation). Most abnormal findings, however, were attributed to antiplatelet medication such as aspirin.  相似文献   
35.
To better understand the potential environmental health risk presented by West Nile virus (WNV)-contaminated feces, we quantified the amount of WNV present in the feces of experimentally infected American crows (Corvus brachyrhynchos) and fish crows (Corvus ossifragus). Peak fecal titers ranged from 10(3.5) to 10(8.8) plaque-forming units (PFU)/g for 10 American crows and from 10(2.3) to 10(6.4) PFU/g for 10 fish crows. The presence of infectious WNV in bird feces indicates a potential for direct transmission of WNV. Thus, handlers of sick or dead birds should take appropriate precautions to avoid exposure to fecal material.  相似文献   
36.
37.
38.
39.
Background: Postoperative pain mostly results from sensitization of afferent fibers at injury sites driving central sensitization. Recently, peripheral processes have gained attention as mechanisms of hyperalgesia, and prostaglandins are among highly sensitizing agents. To date, perioperative administration of a single local dose of nonsteroidal antiinflammatory drugs has shown inconclusive efficacy. Rather than a single bolus, the current study evaluates the postoperative analgesic effect of diclofenac continuous intrawound infusion after elective cesarean delivery.

Methods: Ninety-two parturients were randomly allocated to receive a 48-h continuous intrawound infusion with 240 ml containing 300 mg diclofenac, 0.2% ropivacaine, or saline. In the ropivacaine and saline groups, patients also received 75 mg intravenous diclofenac every 12 h for 48 h. Postoperative evaluation included intravenous morphine consumption by patient-controlled analgesia and visual analog pain scores. Punctate mechanical hyperalgesia surrounding the wound and presence of residual pain after 1 and 6 months were also assessed.

Results: Continuous diclofenac infusion significantly reduced postoperative morphine consumption (18 mg; 95% confidence interval, 12.7-22.2) in comparison with saline infusion and systemic diclofenac (38 mg; 95% confidence interval, 28.8-43.7) (P = 0.0009) without unique adverse effects. Postoperative analgesia produced by local diclofenac infusion was as effective as local ropivacaine infusion with systemic diclofenac.  相似文献   

40.
The use of epidemiologic research designs and analytical methods is common in dietetics research. Food and nutrition professionals who seek to perform evidence-based practice or participate in research design, analysis, and communication need skills in the essentials of epidemiology. This is one of a series of monographs on research methodology that addresses these needs and supports the goals of the Board of Editors of the Journal of the American Dietetic Association to further enhance competency and skills. This monograph focuses on statistical approaches for univariate analyses used with the primary observational study designs associated with epidemiology. Tables illustrating the presentation and interpretation of these results are included.  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