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   1555612篇
  免费   112070篇
  国内免费   3896篇
耳鼻咽喉   22208篇
儿科学   46025篇
妇产科学   42717篇
基础医学   216154篇
口腔科学   43824篇
临床医学   135210篇
内科学   308740篇
皮肤病学   33242篇
神经病学   127870篇
特种医学   61064篇
外国民族医学   444篇
外科学   241862篇
综合类   34202篇
现状与发展   6篇
一般理论   735篇
预防医学   111382篇
眼科学   37245篇
药学   115217篇
  10篇
中国医学   3302篇
肿瘤学   90119篇
  2019年   12659篇
  2018年   17026篇
  2017年   13505篇
  2016年   14939篇
  2015年   17047篇
  2014年   24271篇
  2013年   35702篇
  2012年   48873篇
  2011年   51510篇
  2010年   30142篇
  2009年   28552篇
  2008年   48289篇
  2007年   52031篇
  2006年   52423篇
  2005年   51210篇
  2004年   49345篇
  2003年   47274篇
  2002年   45903篇
  2001年   65485篇
  2000年   66784篇
  1999年   57416篇
  1998年   17378篇
  1997年   15708篇
  1996年   14851篇
  1995年   14021篇
  1994年   12993篇
  1992年   43888篇
  1991年   42299篇
  1990年   41426篇
  1989年   40382篇
  1988年   37811篇
  1987年   37237篇
  1986年   35727篇
  1985年   33944篇
  1984年   25869篇
  1983年   22028篇
  1982年   13857篇
  1981年   12681篇
  1979年   24535篇
  1978年   17700篇
  1977年   15379篇
  1976年   13876篇
  1975年   15653篇
  1974年   18480篇
  1973年   17897篇
  1972年   17092篇
  1971年   15946篇
  1970年   15120篇
  1969年   14490篇
  1968年   13580篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
91.
92.
93.

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   
94.
95.
96.
97.
98.
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   
99.
100.
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