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   1276854篇
  免费   99938篇
  国内免费   1988篇
耳鼻咽喉   18423篇
儿科学   44372篇
妇产科学   35021篇
基础医学   182248篇
口腔科学   33599篇
临床医学   111212篇
内科学   258157篇
皮肤病学   28032篇
神经病学   100341篇
特种医学   51229篇
外国民族医学   660篇
外科学   196583篇
综合类   27062篇
现状与发展   1篇
一般理论   378篇
预防医学   95671篇
眼科学   27923篇
药学   94779篇
  3篇
中国医学   2423篇
肿瘤学   70663篇
  2018年   13165篇
  2017年   9984篇
  2016年   10917篇
  2015年   12407篇
  2014年   17209篇
  2013年   26247篇
  2012年   36067篇
  2011年   38131篇
  2010年   22833篇
  2009年   21840篇
  2008年   36677篇
  2007年   39296篇
  2006年   39533篇
  2005年   38487篇
  2004年   37619篇
  2003年   36467篇
  2002年   35826篇
  2001年   64014篇
  2000年   66513篇
  1999年   56424篇
  1998年   15133篇
  1997年   13760篇
  1996年   14202篇
  1995年   13458篇
  1994年   12765篇
  1993年   11795篇
  1992年   44570篇
  1991年   43480篇
  1990年   42226篇
  1989年   40120篇
  1988年   36907篇
  1987年   36246篇
  1986年   33625篇
  1985年   32286篇
  1984年   24139篇
  1983年   20275篇
  1982年   11723篇
  1981年   10691篇
  1980年   9517篇
  1979年   21346篇
  1978年   14824篇
  1977年   12535篇
  1976年   11699篇
  1975年   12624篇
  1974年   14666篇
  1973年   14120篇
  1972年   12947篇
  1971年   11732篇
  1970年   11056篇
  1969年   10024篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
71.
72.

Background

Arterial vascular anomalies in patients undergoing kidney transplantation (KT) are correlated with a higher incidence of early surgical complications, potentially causing graft loss. Arterial reconstruction allows patients to overcome these surgical challenges, thus minimizing the risk of poor outcomes. The aim of the present study is to retrospectively investigate the safety and effectiveness of the multiple arterial reconstruction technique with a Teflon patch in case of an unavailable aortic patch: to do so, surgical complications, graft function, and patient survival were evaluated.

Methods

During the period January 2009 to August 2016, 202 adult deceased-donor KTs were performed at our center. Group A (n = 27; reconstruction of multiple arteries) and Group B (n = 175; control group) were compared.

Results

No differences were observed between the 2 groups in terms of early postoperative course, with no vascular complication observed in Group A. No vascular patch infections were reported, nor longer cold ischemia time rates. Similarly, long-term survival rates were similar between the 2 groups.

Conclusions

The Teflon-patch arterial reconstruction technique appears to be safe and effective, with an acceptable balance of benefits and potential risks of using a prosthetic material. Studies based on larger series are needed to further validate this approach.  相似文献   
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.
75.
76.
77.
78.
Demodex mites are microscopic arachnids found in the normal skin of many mammals. In humans, it is well established that Demodex mite density is higher in patients with the skin condition rosacea, and treatment with acaricidal agents is effective in resolving symptoms. However, pathophysiology of rosacea is complex and multifactorial. In dogs, demodicosis is a significant veterinary issue, particularly the generalized form of the disease which can be fatal if untreated. In each species, clinical and molecular studies have shown that the host’s immunological interactions with Demodex mites are an important, but not fully understood, aspect of how Demodex can live in the skin either as a harmless commensal organism or as a pathogenic agent. This review outlines the role of Demodex mites in humans and dogs, considering morphology, prevalence, symptoms, diagnosis, histology treatment and pathogenesis.  相似文献   
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