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   4094315篇
  免费   319137篇
  国内免费   16594篇
耳鼻咽喉   56169篇
儿科学   125947篇
妇产科学   106453篇
基础医学   631929篇
口腔科学   113761篇
临床医学   374765篇
内科学   732141篇
皮肤病学   101078篇
神经病学   343864篇
特种医学   158497篇
外国民族医学   458篇
外科学   624893篇
综合类   118249篇
现状与发展   23篇
一般理论   2429篇
预防医学   341829篇
眼科学   94084篇
药学   287422篇
  29篇
中国医学   11916篇
肿瘤学   204110篇
  2021年   55885篇
  2020年   35570篇
  2019年   58683篇
  2018年   73413篇
  2017年   56034篇
  2016年   61806篇
  2015年   75467篇
  2014年   109881篇
  2013年   175585篇
  2012年   112677篇
  2011年   115908篇
  2010年   123035篇
  2009年   125268篇
  2008年   102503篇
  2007年   107545篇
  2006年   117272篇
  2005年   111934篇
  2004年   112923篇
  2003年   102943篇
  2002年   92519篇
  2001年   147478篇
  2000年   142584篇
  1999年   133200篇
  1998年   69609篇
  1997年   66323篇
  1996年   64039篇
  1995年   59512篇
  1994年   53584篇
  1993年   49873篇
  1992年   96721篇
  1991年   92830篇
  1990年   88714篇
  1989年   86592篇
  1988年   80096篇
  1987年   78174篇
  1986年   74090篇
  1985年   73215篇
  1984年   62043篇
  1983年   55492篇
  1982年   46081篇
  1981年   42977篇
  1980年   40287篇
  1979年   52602篇
  1978年   43101篇
  1977年   38717篇
  1976年   35639篇
  1975年   34892篇
  1974年   37987篇
  1973年   36343篇
  1972年   34147篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Bulletin of Experimental Biology and Medicine - Ammonium, an end-product of catabolism, in low doses can promote adaptation of metabolic pathways in erythrocytes under conditions of extreme...  相似文献   
32.
Introduction: Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype associated with an increased risk of recurrence and cancer-related death. Unlike hormone receptor-positive or HER2-positive breast cancers, there are limited targeted therapies available to treat TNBC and cytotoxic chemotherapy remains the mainstay of treatment. Sacituzumab govitecan (IMMU-132) is an antibody-drug conjugate targeting Trop-2 expressing cells and selectively delivering SN-38, an active metabolite of irinotecan.

Areas covered: This review covers the mechanism of action, safety and efficacy of sacituzumab govitecan in patients with previously treated, metastatic TNBC. Additionally, efficacy data in other epithelial malignancies is included based on a PubMed search for ‘sacituzumab govitecan’ and ‘clinical trial’.

Expert opinion: Sacituzumab govitecan has promising anti-cancer activity in patients with metastatic TNBC previously treated with at least two prior lines of systemic therapy based on a single arm Phase I/II clinical trial. A confirmatory Phase III randomized clinical trial is ongoing. Sacituzumab govitecan has a manageable side effect profile, with the most common adverse events being nausea, neutropenia, and diarrhea. The activity of sacituzumab govitecan likely extends beyond TNBC with promising early efficacy data in many other epithelial cancers, including hormone receptor-positive breast cancer.  相似文献   

33.
34.

Objectives

Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.

Methods

Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.

Results

A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.

Conclusions

Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight.  相似文献   
35.
36.
37.
38.
39.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support.  相似文献   
40.
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