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   1996029篇
  免费   151348篇
  国内免费   4303篇
耳鼻咽喉   29955篇
儿科学   59207篇
妇产科学   57709篇
基础医学   282062篇
口腔科学   60625篇
临床医学   172015篇
内科学   385216篇
皮肤病学   43196篇
神经病学   161129篇
特种医学   80053篇
外国民族医学   590篇
外科学   311904篇
综合类   50795篇
现状与发展   7篇
一般理论   674篇
预防医学   146030篇
眼科学   47927篇
药学   150253篇
  3篇
中国医学   4118篇
肿瘤学   108212篇
  2018年   17429篇
  2015年   17889篇
  2014年   25316篇
  2013年   38776篇
  2012年   51128篇
  2011年   53886篇
  2010年   31894篇
  2009年   30626篇
  2008年   51636篇
  2007年   56271篇
  2006年   56656篇
  2005年   55163篇
  2004年   54026篇
  2003年   52170篇
  2002年   50897篇
  2001年   88769篇
  2000年   91194篇
  1999年   77454篇
  1998年   21798篇
  1997年   19971篇
  1996年   19284篇
  1995年   18270篇
  1994年   17344篇
  1992年   62652篇
  1991年   60709篇
  1990年   59733篇
  1989年   58098篇
  1988年   54363篇
  1987年   53567篇
  1986年   51244篇
  1985年   49012篇
  1984年   37340篇
  1983年   31759篇
  1982年   19528篇
  1981年   17984篇
  1980年   16734篇
  1979年   36775篇
  1978年   26372篇
  1977年   22708篇
  1976年   20632篇
  1975年   22990篇
  1974年   27876篇
  1973年   26966篇
  1972年   25773篇
  1971年   24063篇
  1970年   22901篇
  1969年   22017篇
  1968年   20300篇
  1967年   18505篇
  1966年   17277篇
排序方式: 共有10000条查询结果,搜索用时 296 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.
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   
97.
98.
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