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   2088809篇
  免费   156297篇
  国内免费   4369篇
耳鼻咽喉   31502篇
儿科学   62354篇
妇产科学   59827篇
基础医学   295609篇
口腔科学   64112篇
临床医学   179828篇
内科学   402177篇
皮肤病学   46057篇
神经病学   170604篇
特种医学   83796篇
外国民族医学   590篇
外科学   325273篇
综合类   51184篇
现状与发展   7篇
一般理论   708篇
预防医学   151791篇
眼科学   50001篇
药学   156844篇
  4篇
中国医学   4267篇
肿瘤学   112940篇
  2018年   19627篇
  2016年   18074篇
  2015年   19929篇
  2014年   27520篇
  2013年   42808篇
  2012年   56282篇
  2011年   59793篇
  2010年   35147篇
  2009年   32673篇
  2008年   57468篇
  2007年   62403篇
  2006年   62480篇
  2005年   60943篇
  2004年   59428篇
  2003年   57674篇
  2002年   56229篇
  2001年   91553篇
  2000年   94659篇
  1999年   79425篇
  1998年   22571篇
  1997年   20634篇
  1996年   19784篇
  1995年   18694篇
  1994年   17753篇
  1992年   63017篇
  1991年   61021篇
  1990年   60003篇
  1989年   58372篇
  1988年   54603篇
  1987年   53828篇
  1986年   51437篇
  1985年   49367篇
  1984年   37716篇
  1983年   32066篇
  1982年   19855篇
  1981年   18243篇
  1979年   36980篇
  1978年   26608篇
  1977年   22918篇
  1976年   20837篇
  1975年   23195篇
  1974年   28079篇
  1973年   27128篇
  1972年   25866篇
  1971年   24183篇
  1970年   23012篇
  1969年   22126篇
  1968年   20411篇
  1967年   18622篇
  1966年   17350篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
101.
102.
103.
104.
105.

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   
106.
107.
108.
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   
109.
110.
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