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   1370692篇
  免费   115414篇
  国内免费   8582篇
耳鼻咽喉   16929篇
儿科学   43352篇
妇产科学   36759篇
基础医学   186891篇
口腔科学   36752篇
临床医学   124989篇
内科学   282965篇
皮肤病学   32198篇
神经病学   112068篇
特种医学   56678篇
外国民族医学   289篇
外科学   213203篇
综合类   37925篇
现状与发展   15篇
一般理论   414篇
预防医学   109038篇
眼科学   29004篇
药学   97370篇
  56篇
中国医学   4468篇
肿瘤学   73325篇
  2018年   14661篇
  2017年   11779篇
  2016年   13829篇
  2015年   15940篇
  2014年   21964篇
  2013年   31566篇
  2012年   38929篇
  2011年   41607篇
  2010年   26282篇
  2009年   25458篇
  2008年   38027篇
  2007年   40364篇
  2006年   41436篇
  2005年   39711篇
  2004年   37742篇
  2003年   36942篇
  2002年   34680篇
  2001年   66775篇
  2000年   68453篇
  1999年   57110篇
  1998年   16999篇
  1997年   15337篇
  1996年   16252篇
  1995年   16437篇
  1994年   15267篇
  1993年   14240篇
  1992年   47208篇
  1991年   45854篇
  1990年   44054篇
  1989年   41878篇
  1988年   38828篇
  1987年   38135篇
  1986年   35907篇
  1985年   34665篇
  1984年   26373篇
  1983年   22121篇
  1982年   13852篇
  1981年   12450篇
  1980年   11721篇
  1979年   23547篇
  1978年   17072篇
  1977年   14385篇
  1976年   13182篇
  1975年   13722篇
  1974年   16093篇
  1973年   15396篇
  1972年   14173篇
  1971年   13036篇
  1970年   11880篇
  1969年   11101篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.

Background

Limited data exists demonstrating the efficacy of minimally invasive surgery (MIS) compared to median sternotomy (MS) for multiple valvular disease (MVD). This systematic review and meta-analysis aims to compare operative and peri-operative outcomes of MIS vs MS in MVD.

Methods

PubMed, Ovid, and Embase were searched from inception until August 2019 for randomized and observational studies comparing MIS and MS in patients with MVD. Clinical outcomes of intra- and postoperative times, reoperation for bleeding and surgical site infection were evaluated.

Results

Five observational studies comparing 340 MIS vs 414 MS patients were eligible for qualitative and quantitative review. The quality of evidence assessed using the Newcastle-Ottawa scale was good for all included studies. Meta-analysis demonstrated increased cardiopulmonary bypass time for MIS patients (weighted mean difference [WMD], 0.487; 95% confidence interval [CI], 0.365-0.608; P < .0001). Similarly, aortic cross-clamp time was longer in patients undergoing MIS (WMD, 0.632; 95% CI, 0.509-0.755; P < .0001). No differences were found in operative mortality, reoperation for bleeding, surgical site infection, or hospital stay.

Conclusions

MIS for MVD have similar short-term outcomes compared to MS. This adds value to the use of minimally invasive methods for multivalvular surgery, despite conferring longer operative times. However, the paucity in literature and learning curve associated with MIS warrants further evidence, ideally randomized control trials, to support these findings.
  相似文献   
63.
64.
65.
66.
67.
ABSTRACT

Objective

To investigate primary care physician clinical practice patterns, barriers, and education surrounding pediatric physical activity (PA), and to compare practice patterns by discipline.  相似文献   
68.
69.
Moderate weight loss improves numerous risk factors for cardiometabolic disease; however, long-term weight loss maintenance (WLM) is often thwarted by metabolic adaptations that suppress energy expenditure and facilitate weight regain. Skeletal muscle has a prominent role in energy homeostasis; therefore, we investigated the effect of WLM and weight regain on skeletal muscle in rodents. In skeletal muscle of obesity-prone rats, WLM reduced fat oxidative capacity and downregulated genes involved in fat metabolism. Interestingly, even after weight was regained, genes involved in fat metabolism were also reduced. We then subjected mice with skeletal muscle lipoprotein lipase overexpression (mCK-hLPL), which augments fat metabolism, to WLM and weight regain and found that mCK-hLPL attenuates weight regain by potentiating energy expenditure. Irrespective of genotype, weight regain suppressed dietary fat oxidation and downregulated genes involved in fat metabolism in skeletal muscle. However, mCK-hLPL mice oxidized more fat throughout weight regain and had greater expression of genes involved in fat metabolism and lower expression of genes involved in carbohydrate metabolism during WLM and regain. In summary, these results suggest that skeletal muscle fat oxidation is reduced during WLM and regain, and therapies that improve skeletal muscle fat metabolism may attenuate rapid weight regain.  相似文献   
70.
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