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   193412篇
  免费   3961篇
  国内免费   440篇
耳鼻咽喉   2749篇
儿科学   7432篇
妇产科学   5845篇
基础医学   24993篇
口腔科学   5731篇
临床医学   15020篇
内科学   34618篇
皮肤病学   4625篇
神经病学   11508篇
特种医学   10702篇
外国民族医学   97篇
外科学   28964篇
综合类   1083篇
一般理论   1篇
预防医学   16234篇
眼科学   4268篇
药学   13454篇
  2篇
中国医学   151篇
肿瘤学   10336篇
  2018年   3490篇
  2017年   3859篇
  2016年   3149篇
  2015年   4815篇
  2014年   4238篇
  2013年   3328篇
  2012年   9722篇
  2011年   4620篇
  2010年   2128篇
  2009年   3786篇
  2008年   1985篇
  2007年   2703篇
  2006年   2972篇
  2005年   11087篇
  2004年   12569篇
  2003年   8153篇
  2002年   3365篇
  2001年   4311篇
  2000年   1673篇
  1999年   5817篇
  1998年   500篇
  1995年   376篇
  1992年   6857篇
  1991年   7093篇
  1990年   7337篇
  1989年   6937篇
  1988年   6466篇
  1987年   6228篇
  1986年   5951篇
  1985年   5240篇
  1984年   3586篇
  1983年   2909篇
  1982年   1000篇
  1981年   765篇
  1980年   838篇
  1979年   3828篇
  1978年   2363篇
  1977年   1781篇
  1976年   1561篇
  1975年   2475篇
  1974年   3106篇
  1973年   2739篇
  1972年   2756篇
  1971年   2742篇
  1970年   2556篇
  1969年   2465篇
  1968年   2237篇
  1967年   2164篇
  1966年   1898篇
  1965年   1132篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
996.
997.
Alprazolam, a new benzodiazepine from triazolobenzodiazepine group, produced anxiolytic action in the conflict test with potency similar to that of diazepam. The myorelaxant activity of the drug was relatively weak. Unlike desipramine, alprazolam failed to reduce the immobility of rats in the forced swim test and was unable to prevent clonidine-induced hypothermia. Alprazolam, unlike desipramine, failed also to potentiate behavioral effect of noradrenaline injected into the hippocampus. Alprazolam after acute but not chronic administration antagonized the synchronizing effect of clonidine on EEG pattern. On the other hand, alprazolam similarly to tricyclic antidepressants, prevented the suppression of dominance behavior by clonidine in rats competing for food. The results indicate that alprazolam acts only weakly upon noradrenergic mechanisms related to depression and to antidepressant action of drugs.  相似文献   
998.
When dealing with patients with periodontal disease of variable severities, dentists must often choose between treating and restoring the involved tooth or indicating its extraction. Different criteria have been adopted in this decision-making process. The purpose of this study was to evaluate the criteria adopted by dentists to indicate the extraction of teeth with periodontitis. Dentists were interviewed at their private practices in three cities of the state of Rio Grande do Sul, Brazil. The evaluated criteria included severity of attachment loss, tooth mobility, furcation involvement, prosthetic planning, periodontal-endodontic lesion, possible systemic involvement due to the presence of periodontitis, referral to a periodontist for evaluation, radiographic bone loss greater than 50%, presence of extensive caries, socio-economic and cultural status of the patient, among others. The most often adopted criteria to indicate the extraction of periodontally affected teeth were the presence of mobility (37.5%), severity of attachment loss (24.3%) and radiographic bone loss greater than 50% (21.2%). The results of the present study demonstrated the difficulties faced by dentists to indicate the extraction of teeth with severe attachment loss, in addition to the establishment of an adequate prognosis. Aspects associated with the past disease were still the most often reported to indicate the extraction of teeth for periodontal reasons.  相似文献   
999.
Hypertension is a well known risk factor of coronary artery disease. The aim of the study was to evaluate a clinical course and prognosis in hypertensive patients with acute myocardial infarction (MI). 100 consecutive patients with acute MI underwent the study. In 38 of them (28 males and 10 females) a history of hypertension and intermittent rises of arterial blood pressure in a course of MI were stated. All patients underwent 2-DE examination and 24 hours Holter ecg monitoring. Clinical characteristics consisted of the heart failure and arrhythmias occurrence as well as the in-hospital mortality. Significantly higher rate of MI in the past and/or angina pectoris as well as a diabetes mellitus was stated in hypertensive patients. In these patients inferior, transmural MI was more often observed, while there was no difference in life-threatening arrhythmias, pulmonary edema and cardiogenic shock between normotensive and hypertensive patients.  相似文献   
1000.
In the case of characteristic chromosomal deletion of chromosome 15(q11----q13) the diagnosis of the Prader-Willi syndrome can be already confirmed in early infancy as shown in our case report. In this connection cytogenetic high-resolution techniques are indispensable. Cytogenetic and clinical problems are discussed.  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