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   1086442篇
  免费   82579篇
  国内免费   2226篇
耳鼻咽喉   15797篇
儿科学   31722篇
妇产科学   29723篇
基础医学   156472篇
口腔科学   30705篇
临床医学   93124篇
内科学   214193篇
皮肤病学   23073篇
神经病学   90179篇
特种医学   41908篇
外国民族医学   271篇
外科学   164299篇
综合类   25526篇
现状与发展   2篇
一般理论   324篇
预防医学   87490篇
眼科学   24950篇
药学   80537篇
中国医学   2271篇
肿瘤学   58681篇
  2019年   9011篇
  2018年   14574篇
  2017年   10511篇
  2016年   11249篇
  2015年   12983篇
  2014年   16573篇
  2013年   25676篇
  2012年   38266篇
  2011年   39337篇
  2010年   21565篇
  2009年   18796篇
  2008年   35891篇
  2007年   38914篇
  2006年   37701篇
  2005年   37161篇
  2004年   35924篇
  2003年   34013篇
  2002年   32508篇
  2001年   41662篇
  2000年   42414篇
  1999年   36161篇
  1998年   10074篇
  1997年   9262篇
  1996年   9132篇
  1995年   8623篇
  1992年   29689篇
  1991年   28831篇
  1990年   28230篇
  1989年   27069篇
  1988年   25498篇
  1987年   24982篇
  1986年   23753篇
  1985年   22895篇
  1984年   17729篇
  1983年   15134篇
  1982年   9491篇
  1981年   8704篇
  1979年   17890篇
  1978年   12920篇
  1977年   10929篇
  1976年   9936篇
  1975年   10913篇
  1974年   13581篇
  1973年   13088篇
  1972年   12440篇
  1971年   11576篇
  1970年   11041篇
  1969年   10769篇
  1968年   9663篇
  1967年   8864篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
72.
73.

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   
74.

Background

Since recent reports have shown that (-)-Epigallocatechin-3-gallate (EGCG) could be used for treating proliferative and inflammatory disorders, we explored its use for the management of corneal chemical burns.

Materials and methods

Initially, EGCG was assayed on the rabbit corneal epithelial cell line RCE1(5T5) to establish the best testing conditions, and to avoid unwanted outcomes in the experimental animals. Then, we studied its effects on cell proliferation, cell cycle progression and cell differentiation. Afterwards, we instilled EGCG in experimental grade II corneal alkali burns in mice, three times a day up to 21 days, and evaluated by slit lamp examination and histological sections of corneal epithelial, corneal endothelial and stromal edema, as well as the presence of inflammatory cells and neovascularization.

Results

EGCG reduced cell growth and led to a decline in the proportion of proliferative cells in a concentration dependent manner. At 10 μM, EGCG promoted cell differentiation, an effect not related with apoptosis or cytotoxicity. When 10 μM EGCG was instilled in corneal alkali burns in mice three times a day up to 21 days, EGCG significantly reduced corneal opacity and neovascularization. The improved clinical appearance of the cornea was associated to a controlled epithelial growth; epithelial morphology was similar to that observed in normal epithelium and contrasted with the hyperproliferative, desquamating epithelium observed in control burn wounds. EGCG reduced corneal, stromal and endothelial edema, and wound inflammation.

Conclusion

This work constitutes the first evidence for the use of EGCG in the acute phase of a corneal alkali burn, representing a possible novel alternative to improve patient outcomes as an add-on therapy.  相似文献   
75.
76.
77.
78.
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