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   191983篇
  免费   35232篇
  国内免费   2518篇
耳鼻咽喉   5713篇
儿科学   6344篇
妇产科学   3034篇
基础医学   8528篇
口腔科学   2210篇
临床医学   31240篇
内科学   55170篇
皮肤病学   7940篇
神经病学   18590篇
特种医学   7989篇
外国民族医学   2篇
外科学   48205篇
综合类   984篇
现状与发展   73篇
一般理论   32篇
预防医学   10515篇
眼科学   4278篇
药学   4328篇
  1篇
中国医学   81篇
肿瘤学   14476篇
  2024年   525篇
  2023年   4987篇
  2022年   1541篇
  2021年   4202篇
  2020年   6537篇
  2019年   3269篇
  2018年   8635篇
  2017年   8183篇
  2016年   9244篇
  2015年   9486篇
  2014年   17051篇
  2013年   17655篇
  2012年   8851篇
  2011年   9091篇
  2010年   12230篇
  2009年   15745篇
  2008年   8687篇
  2007年   7249篇
  2006年   9519篇
  2005年   6672篇
  2004年   5593篇
  2003年   4559篇
  2002年   4357篇
  2001年   4065篇
  2000年   3160篇
  1999年   3500篇
  1998年   4062篇
  1997年   3746篇
  1996年   3609篇
  1995年   3453篇
  1994年   2165篇
  1993年   1742篇
  1992年   1510篇
  1991年   1529篇
  1990年   1179篇
  1989年   1309篇
  1988年   1137篇
  1987年   961篇
  1986年   977篇
  1985年   833篇
  1984年   686篇
  1983年   643篇
  1982年   670篇
  1981年   536篇
  1980年   512篇
  1979年   380篇
  1978年   414篇
  1977年   455篇
  1975年   328篇
  1972年   327篇
排序方式: 共有10000条查询结果,搜索用时 765 毫秒
41.
42.
43.
44.
45.
46.

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   
47.
48.
49.
Breast elastography has been available for more than 15 years but is not widely incorporated into clinical practice. Many publications report extremely high accuracy for various breast elastographic techniques. However, results in the literature are extremely variable. This variability is most likely due to variations in technique, a relatively steep learning curve, and variability in methods between vendors. This article describes our protocol for performing breast elastography using both strain elastography and shear wave elastography, which produces high sensitivity and specificity. Additionally, we will describe the most commonly known false-positive and false-negative lesions as well as how to detect them.  相似文献   
50.
The term “oligometastatic prostate cancer” refers to a heterogeneous group of disease states currently defined solely on the basis of clinical features. Oligorecurrent disease, de novo oligometastases, and oligoprogressive disease likely have unique biologic underpinnings and natural histories. Evidence suggesting the existence of a subset of patients who harbor prostate cancer with limited metastatic potential currently includes disparate and overwhelmingly retrospective reports. Nevertheless, emerging prospective data have corroborated the “better-than-expected,” retrospectively observed outcomes, particularly in the setting of oligorecurrent prostate cancer. Improved functional imaging with prostate-specific membrane antigen-targeted strategies may enhance the identification of patients with oligometastatic prostate cancer in the short term. In the long term, refinement of the oligometastatic case definition likely will require biologic risk-stratification schemes. To determine optimal treatment strategies and identify patients most likely to benefit from metastasis-directed therapy, future efforts should focus on conducting high-quality, prospective trials with much-needed molecular correlative studies.  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