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   1461222篇
  免费   101201篇
  国内免费   3237篇
耳鼻咽喉   21987篇
儿科学   44915篇
妇产科学   41786篇
基础医学   205090篇
口腔科学   43678篇
临床医学   122110篇
内科学   284636篇
皮肤病学   33917篇
神经病学   118326篇
特种医学   60239篇
外国民族医学   455篇
外科学   228822篇
综合类   32242篇
现状与发展   6篇
一般理论   467篇
预防医学   98166篇
眼科学   35114篇
药学   108926篇
  3篇
中国医学   3341篇
肿瘤学   81434篇
  2018年   14147篇
  2016年   13284篇
  2015年   14907篇
  2014年   19885篇
  2013年   29771篇
  2012年   39983篇
  2011年   41354篇
  2010年   24529篇
  2009年   23249篇
  2008年   40000篇
  2007年   43735篇
  2006年   44239篇
  2005年   43342篇
  2004年   42075篇
  2003年   40999篇
  2002年   40415篇
  2001年   67722篇
  2000年   69248篇
  1999年   58851篇
  1998年   15797篇
  1997年   14345篇
  1996年   13642篇
  1995年   12785篇
  1994年   11992篇
  1992年   44202篇
  1991年   42602篇
  1990年   41886篇
  1989年   40760篇
  1988年   38018篇
  1987年   37481篇
  1986年   35842篇
  1985年   33998篇
  1984年   25549篇
  1983年   21618篇
  1982年   13092篇
  1981年   11959篇
  1979年   24710篇
  1978年   17645篇
  1977年   15307篇
  1976年   13826篇
  1975年   15845篇
  1974年   18672篇
  1973年   18105篇
  1972年   17399篇
  1971年   16277篇
  1970年   15415篇
  1969年   14801篇
  1968年   13930篇
  1967年   12426篇
  1966年   11593篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
71.
72.
73.
74.

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   
75.
76.
77.
78.
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   
79.
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