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   1586862篇
  免费   112836篇
  国内免费   4989篇
耳鼻咽喉   23658篇
儿科学   46407篇
妇产科学   45736篇
基础医学   222988篇
口腔科学   47999篇
临床医学   134188篇
内科学   312605篇
皮肤病学   35799篇
神经病学   124767篇
特种医学   62374篇
外国民族医学   508篇
外科学   247328篇
综合类   38199篇
现状与发展   6篇
一般理论   498篇
预防医学   104627篇
眼科学   38621篇
药学   120462篇
  4篇
中国医学   4576篇
肿瘤学   93337篇
  2018年   14959篇
  2016年   13091篇
  2015年   14717篇
  2014年   20774篇
  2013年   30700篇
  2012年   40300篇
  2011年   42467篇
  2010年   25334篇
  2009年   24568篇
  2008年   40403篇
  2007年   44186篇
  2006年   44440篇
  2005年   42704篇
  2004年   41359篇
  2003年   40023篇
  2002年   39326篇
  2001年   80256篇
  2000年   82283篇
  1999年   69511篇
  1998年   18175篇
  1997年   16370篇
  1996年   15510篇
  1995年   14586篇
  1994年   13565篇
  1993年   12589篇
  1992年   52979篇
  1991年   50531篇
  1990年   49511篇
  1989年   48302篇
  1988年   44886篇
  1987年   44060篇
  1986年   41887篇
  1985年   39810篇
  1984年   29404篇
  1983年   24841篇
  1982年   14571篇
  1981年   13109篇
  1979年   27813篇
  1978年   19490篇
  1977年   16997篇
  1976年   15082篇
  1975年   17220篇
  1974年   20316篇
  1973年   19730篇
  1972年   18940篇
  1971年   17807篇
  1970年   16755篇
  1969年   16213篇
  1968年   15134篇
  1967年   13447篇
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
71.
72.
73.
74.
75.
76.

Objective

Arch obstruction after the Norwood procedure is common and contributes to mortality. We determined the prevalence, associated factors, and practice variability of arch reintervention and assessed whether arch reintervention is associated with mortality.

Methods

From 2005 to 2017, 593 neonates in the Congenital Heart Surgeons' Society Critical Left Heart Obstruction cohort underwent a Norwood procedure. Median follow-up was 3.7 years. Multivariable parametric models, including a modulated renewal analysis, were performed.

Results

Of the 593 neonates, 146 (25%) underwent 218 reinterventions for arch obstruction after the Norwood procedure: catheter-based (n = 168) or surgical (n = 50) at a median age of 4.3 months (quartile 1-quartile 3, 2.6-5.7). Interdigitation of the distal aortic anastomosis was protective against arch reintervention. Development of ≥ moderate tricuspid valve regurgitation and right ventricular dysfunction at any point was associated with arch reintervention. Nonsignificant variables for arch reintervention included shunt type and preoperative aortic measurements. Surgical arch reintervention was protective against arch reintervention, but transcatheter reintervention was associated with increased reintervention. Arch reintervention was not associated with increased mortality. There was wide institutional variation in incidence of arch reintervention (range, 0-40 reinterventions per 100 years patient follow-up) and in preintervention gradient (range, 0-64 mm Hg).

Conclusions

Interdigitation of the distal aortic anastomosis during the Norwood procedure decreased the risk of arch reintervention. Surgical arch reintervention is more definitive than transcatheter. Arch reintervention after the Norwood procedure is not associated with increased mortality. Serial surveillance for arch obstruction, integrated with changes in right ventricular function and tricuspid valve regurgitation, is recommended after the Norwood procedure to improve outcomes.  相似文献   
77.
78.
79.
There are an estimated 56 million orphans and vulnerable children across sub-Saharan Africa. Communities typically care for orphan children through informal caring arrangements – either within or outside of kinship networks. Within Kenya, an estimated 250,000 children live on the streets. There is less research related to fostering attitudes of this special population than orphans and vulnerable children generally. Important research over the past decade has illuminated multiple ways in which children are made more vulnerable because of HIV, including parental death and street-migration from HIV-affected households. As HIV transitions from a terminal illness to a chronic, manageable one, research is also required to establish how parents living with HIV can be an asset to children. In this study, we assess whether mothers living with HIV were very willing to foster biologically-related children, and street-involved children, how these fostering attitudes differed from mothers not living with HIV, and whether differences in fostering attitudes by reported HIV status were mediated by social support, family functioning and general self-rated health. Approximately 40% of mothers living with HIV were very willing to provide long-term foster care to biologically-related or street-involved children. This was less than the percentage of mothers not living with HIV, who were very willing to foster biologically-related children (61%) or street-involved children (58%). Significant portions of these differences were explained by social support, family functioning and general self-rated health. Multi-sectoral approaches are suggested by these findings in order to improve the child-fostering capacity of mothers living with HIV. Improving social support, family functioning and general self-rated health among HIV-infected mothers may not only provide protective benefits for the mothers and their children, but also expand the community’s capacity to care for orphan and vulnerable children.  相似文献   
80.
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