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   1152446篇
  免费   85964篇
  国内免费   2471篇
耳鼻咽喉   16642篇
儿科学   33964篇
妇产科学   31640篇
基础医学   165396篇
口腔科学   32652篇
临床医学   97776篇
内科学   229991篇
皮肤病学   25456篇
神经病学   95908篇
特种医学   43441篇
外国民族医学   298篇
外科学   172968篇
综合类   25902篇
现状与发展   2篇
一般理论   336篇
预防医学   93593篇
眼科学   26082篇
药学   84835篇
中国医学   2530篇
肿瘤学   61469篇
  2021年   10427篇
  2019年   10801篇
  2018年   16243篇
  2017年   11604篇
  2016年   12397篇
  2015年   14208篇
  2014年   18779篇
  2013年   28583篇
  2012年   42020篇
  2011年   43312篇
  2010年   23993篇
  2009年   21409篇
  2008年   39013篇
  2007年   42163篇
  2006年   40895篇
  2005年   40518篇
  2004年   38901篇
  2003年   36911篇
  2002年   35279篇
  2001年   43696篇
  2000年   44494篇
  1999年   37909篇
  1998年   10861篇
  1997年   9852篇
  1996年   9644篇
  1995年   9091篇
  1992年   30447篇
  1991年   29579篇
  1990年   28889篇
  1989年   27599篇
  1988年   25976篇
  1987年   25477篇
  1986年   24219篇
  1985年   23351篇
  1984年   18060篇
  1983年   15403篇
  1982年   9686篇
  1979年   18173篇
  1978年   13127篇
  1977年   11090篇
  1976年   10130篇
  1975年   11142篇
  1974年   13817篇
  1973年   13325篇
  1972年   12668篇
  1971年   11804篇
  1970年   11271篇
  1969年   10985篇
  1968年   9858篇
  1967年   9055篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
This study used the National Survey of Ambulatory Surgery (NSAS) database to measure the incidence of and risk factors for symptoms in the ambulatory surgery center and problems within 24 h after isolated carpal tunnel release (CTR). The NSAS contained records on 400,000 adult patients with carpal tunnel syndrome who were treated with CTR in 2006, based on ICD-9 codes. The type of anesthesia used and factors associated with symptoms and problems were sought in bivariate and multivariable statistical analyses. The mean duration of the procedure was 16 ± 8.8 min. Only 5 % were performed under local anesthesia without sedation, 45 % with IV sedation, 28 % regional anesthesia, and 19 % general anesthesia. Symptoms in the ambulatory surgery center or a problem within 24 h after discharge were recorded in 10 % of patients, all of them minor and transient, including difficulties with pain and its treatment. The strongest risk factors were male sex, age of 45 years and older, and participation of an anesthesiologist. Local anesthesia and regional anesthesia were associated with more perioperative symptoms and postoperative problems. Most CTR are performed with some sedation in the United States. CTR is a safe procedure: one in 10 patients will experience a minor issue in the perioperative or immediate postoperative period.  相似文献   
72.
73.
74.
75.
76.
77.
78.
79.

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   
80.

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   
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