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   1786871篇
  免费   128929篇
  国内免费   4795篇
耳鼻咽喉   23287篇
儿科学   58222篇
妇产科学   49606篇
基础医学   254681篇
口腔科学   52006篇
临床医学   158418篇
内科学   349961篇
皮肤病学   40586篇
神经病学   137493篇
特种医学   66952篇
外国民族医学   244篇
外科学   270417篇
综合类   42618篇
现状与发展   4篇
一般理论   563篇
预防医学   130932篇
眼科学   42573篇
药学   131116篇
  7篇
中国医学   5059篇
肿瘤学   105850篇
  2021年   13788篇
  2019年   14498篇
  2018年   21554篇
  2017年   16359篇
  2016年   17875篇
  2015年   20256篇
  2014年   28050篇
  2013年   40348篇
  2012年   55803篇
  2011年   58657篇
  2010年   34844篇
  2009年   32329篇
  2008年   54049篇
  2007年   57496篇
  2006年   57924篇
  2005年   54892篇
  2004年   52937篇
  2003年   50164篇
  2002年   48262篇
  2001年   96200篇
  2000年   98142篇
  1999年   80755篇
  1998年   21094篇
  1997年   18301篇
  1996年   18024篇
  1995年   17321篇
  1994年   15827篇
  1993年   14605篇
  1992年   59972篇
  1991年   57906篇
  1990年   55492篇
  1989年   53273篇
  1988年   48574篇
  1987年   47285篇
  1986年   44418篇
  1985年   42151篇
  1984年   30833篇
  1983年   26230篇
  1982年   14632篇
  1979年   27004篇
  1978年   18487篇
  1977年   15656篇
  1976年   14603篇
  1975年   15508篇
  1974年   18737篇
  1973年   18051篇
  1972年   16765篇
  1971年   15485篇
  1970年   14346篇
  1969年   13457篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Case report 506   总被引:1,自引:0,他引:1  
  相似文献   
132.
Electrocardiographic symptoms were evaluated in 53 patients with an additional left-ventricular chorda (ALVC), detected by two-dimensional echocardiography. Signs of early ventricular repolarization (EVR) were identified in 45 (84.9%) patients. A transverse ALVC was more common in EVR-free patients (87.5%), as compared to patients with ALVC + EVR combinations (51.1%; p less than 0.05).  相似文献   
133.
We compared the effects of alpha 2- and beta-adrenoreceptor blockade on the central actions of catecholamines and metabolites of alpha-methyldihydroxyphenylalanine, epinephrine, alpha-methylnorepinephrine, and alpha-methylepinephrine were studied. I.c.v. and nucleus tractus solitarii (NTS) injections were carried out under anesthesia. Following i.c.v. injection, both epinephrine and methylepinephrine rapidly reduced blood pressure and heart rate, but the effects of methylnorepinephrine occurred somewhat later. Following microinjection into the nucleus of the solitary tract, epinephrine, methylepinephrine, and methylnorepinephrine all caused hypotension and bradycardia. The hypotensive effects of all 3 amines in the NTS were attenuated in additive fashion by yohimbine, an alpha 2 adrenoreceptor antagonist, and timolol, a beta-adrenoreceptor antagonist, whereas only yohimbine attenuated the bradycardia. The combination of yohimbine and timolol abolished the effects of the amines. These data suggest that in the NTS both alpha 2 and beta adrenoreceptor stimulation contribute to the hypotensive effects of these amines, but that only alpha 2 adrenoreceptors are principally involved in the heart rate response.  相似文献   
134.
135.
Eighty-nine cases of chronic bronchitis were matched against167 asymptomatic controls from the glass bangle industry ofFirozabad. Factors of age, social status, smoking habit andduration of exposure were studied. Duration of exposure wasfound to be a factor contributing significantly to the causationof disease. Requests for reprints should be addressed to: Dr B. N. Gupta, Division of Epidemilogy, Industrial Toxicology Research Centre, Mahatma Gandhi Marg, Lucknow P.O. Box 80, 226001, India  相似文献   
136.
137.
We evaluated the therapeutic efficacy of miconazole (MCZ, Florid-F inj.), a new antifungal agent for parenteral use, in deep-seated fungal infections of respiratory tract system. A daily dose of 400-1,800 mg of MCZ was given intravenously for 12-38 days (mean: 23.4 days) to 7 patients: 2 patients with pulmonary aspergillosis, 1 patient with bronchial aspergillosis, 1 patient with pulmonary candidiasis and 3 patients with candidemia. One additional patient with pulmonary aspergillosis received three instillations of 20 mg of MCZ into the thoracic cavity. The clinical effects were excellent in 1, good in 4 and poor in 3 patients. The efficacy rate was 100% in 5 cases with respiratory fungal infections but 3 cases with candidemia did not respond well to the treatment. Four strains each of Aspergillus sp. and Candida sp. were identified as causative organisms. Seven of the 8 strains were eradicated by administration of MCZ. Side effects observed were irritation and heat in a leg in 1 patient, hyperlipoidemia in 2 patients and eosinophilia in 1 patient. The adverse reactions disappeared after the completion of the therapy. From the above results, we conclude that MCZ is one of the most useful antifungal agents for parenteral use as a first choice on deep-seated fungal infections in the respiratory tract.  相似文献   
138.
139.
140.
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