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   1416435篇
  免费   97728篇
  国内免费   2296篇
耳鼻咽喉   20000篇
儿科学   46219篇
妇产科学   41124篇
基础医学   206898篇
口腔科学   40283篇
临床医学   116198篇
内科学   282206篇
皮肤病学   30457篇
神经病学   110587篇
特种医学   53442篇
外国民族医学   367篇
外科学   213197篇
综合类   27176篇
现状与发展   1篇
一般理论   322篇
预防医学   108990篇
眼科学   33132篇
药学   108574篇
  1篇
中国医学   3023篇
肿瘤学   74262篇
  2018年   16104篇
  2017年   11586篇
  2016年   12698篇
  2015年   14530篇
  2014年   19225篇
  2013年   29375篇
  2012年   42370篇
  2011年   45347篇
  2010年   25731篇
  2009年   23311篇
  2008年   42679篇
  2007年   46184篇
  2006年   46486篇
  2005年   45404篇
  2004年   43456篇
  2003年   41926篇
  2002年   41123篇
  2001年   61919篇
  2000年   63880篇
  1999年   53873篇
  1998年   14800篇
  1997年   13178篇
  1996年   13414篇
  1995年   12656篇
  1994年   12017篇
  1992年   42708篇
  1991年   41865篇
  1990年   41408篇
  1989年   40001篇
  1988年   37366篇
  1987年   36486篇
  1986年   34898篇
  1985年   33222篇
  1984年   24713篇
  1983年   21480篇
  1982年   12737篇
  1981年   11250篇
  1979年   23599篇
  1978年   16530篇
  1977年   14362篇
  1976年   13579篇
  1975年   14934篇
  1974年   17565篇
  1973年   17015篇
  1972年   16205篇
  1971年   15120篇
  1970年   14031篇
  1969年   13624篇
  1968年   12887篇
  1967年   11280篇
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
31.
32.
33.
34.
BackgroundThe aim of this paper is to assess the current state of quality and outcomes measures being reported for hepatic resections in the recent literature.MethodsMedline and PubMed databases were searched for English language articles published between 1 January 2002 and 30 April 2013. Two examiners reviewed each article and relevant citations for appropriateness of inclusion, which excluded papers of liver donor hepatic resections, repeat hepatectomies or meta-analyses. Data were extracted and summarized by two examiners for analysis.ResultsFifty-five studies were identified with suitable reporting to assess peri-operative mortality in hepatic resections. In only 35% (19/55) of the studies was the follow-up time explicitly stated, and in 47% (26/55) of studies peri-operative mortality was limited to in-hospital or 30 days. The time period in which complications were captured was not explicitly stated in 19 out of 28 studies. The remaining studies only captured complications within 30 days of the index operation (8/28). There was a paucity of quality literature addressing truly patient-centred outcomes.ConclusionQuality outcomes after a hepatic resection are inconsistently reported in the literature. Quality outcome studies for a hepatectomy should report mortality and morbidity at a minimum of 90 days after surgery.  相似文献   
35.
36.
37.
38.
39.
40.
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN.  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