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   1335594篇
  免费   96056篇
  国内免费   2904篇
耳鼻咽喉   19774篇
儿科学   40334篇
妇产科学   38728篇
基础医学   187584篇
口腔科学   39856篇
临床医学   112639篇
内科学   262398篇
皮肤病学   30376篇
神经病学   106455篇
特种医学   53768篇
外国民族医学   435篇
外科学   208616篇
综合类   31028篇
现状与发展   6篇
一般理论   442篇
预防医学   91952篇
眼科学   31365篇
药学   100171篇
  2篇
中国医学   2988篇
肿瘤学   75637篇
  2018年   11775篇
  2015年   11917篇
  2014年   16721篇
  2013年   25325篇
  2012年   33093篇
  2011年   34970篇
  2010年   20790篇
  2009年   20298篇
  2008年   33663篇
  2007年   36773篇
  2006年   37348篇
  2005年   36129篇
  2004年   35177篇
  2003年   34123篇
  2002年   33677篇
  2001年   63662篇
  2000年   65378篇
  1999年   55433篇
  1998年   14669篇
  1997年   13478篇
  1996年   12956篇
  1995年   12235篇
  1994年   11481篇
  1992年   42789篇
  1991年   41312篇
  1990年   40588篇
  1989年   39570篇
  1988年   36984篇
  1987年   36435篇
  1986年   34924篇
  1985年   33123篇
  1984年   24841篇
  1983年   21063篇
  1982年   12675篇
  1981年   11577篇
  1980年   10774篇
  1979年   23935篇
  1978年   17075篇
  1977年   14842篇
  1976年   13389篇
  1975年   15269篇
  1974年   18083篇
  1973年   17571篇
  1972年   16820篇
  1971年   15727篇
  1970年   14889篇
  1969年   14326篇
  1968年   13448篇
  1967年   11998篇
  1966年   11249篇
排序方式: 共有10000条查询结果,搜索用时 15 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