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   1334399篇
  免费   95996篇
  国内免费   2906篇
耳鼻咽喉   19711篇
儿科学   40220篇
妇产科学   38670篇
基础医学   187303篇
口腔科学   39829篇
临床医学   112588篇
内科学   262385篇
皮肤病学   30212篇
神经病学   106356篇
特种医学   53690篇
外国民族医学   435篇
外科学   208391篇
综合类   31033篇
现状与发展   6篇
一般理论   436篇
预防医学   91943篇
眼科学   31368篇
药学   100045篇
  3篇
中国医学   2987篇
肿瘤学   75690篇
  2018年   11771篇
  2015年   11889篇
  2014年   16710篇
  2013年   25273篇
  2012年   33040篇
  2011年   34916篇
  2010年   20763篇
  2009年   20262篇
  2008年   33615篇
  2007年   36720篇
  2006年   37289篇
  2005年   36065篇
  2004年   35143篇
  2003年   34096篇
  2002年   33628篇
  2001年   63630篇
  2000年   65337篇
  1999年   55402篇
  1998年   14659篇
  1997年   13471篇
  1996年   12948篇
  1995年   12225篇
  1994年   11474篇
  1992年   42773篇
  1991年   41286篇
  1990年   40560篇
  1989年   39562篇
  1988年   36968篇
  1987年   36414篇
  1986年   34910篇
  1985年   33110篇
  1984年   24833篇
  1983年   21059篇
  1982年   12665篇
  1981年   11569篇
  1980年   10776篇
  1979年   23924篇
  1978年   17069篇
  1977年   14836篇
  1976年   13387篇
  1975年   15272篇
  1974年   18082篇
  1973年   17564篇
  1972年   16814篇
  1971年   15718篇
  1970年   14917篇
  1969年   14348篇
  1968年   13460篇
  1967年   12015篇
  1966年   11259篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
61.

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   
62.
63.
64.
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   
65.
66.
67.
68.
69.
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