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   2589320篇
  免费   185132篇
  国内免费   7583篇
耳鼻咽喉   34276篇
儿科学   85233篇
妇产科学   71578篇
基础医学   363759篇
口腔科学   69725篇
临床医学   234721篇
内科学   516078篇
皮肤病学   62462篇
神经病学   213646篇
特种医学   99913篇
外国民族医学   736篇
外科学   386706篇
综合类   50398篇
现状与发展   5篇
一般理论   968篇
预防医学   196231篇
眼科学   56692篇
药学   188210篇
  8篇
中国医学   5333篇
肿瘤学   145357篇
  2021年   20018篇
  2019年   20638篇
  2018年   29312篇
  2017年   22616篇
  2016年   26253篇
  2015年   29534篇
  2014年   40482篇
  2013年   60477篇
  2012年   80306篇
  2011年   84621篇
  2010年   51069篇
  2009年   49205篇
  2008年   79113篇
  2007年   83925篇
  2006年   85643篇
  2005年   81818篇
  2004年   78816篇
  2003年   76142篇
  2002年   73423篇
  2001年   128460篇
  2000年   131369篇
  1999年   110544篇
  1998年   31269篇
  1997年   27935篇
  1996年   28238篇
  1995年   27397篇
  1994年   25077篇
  1993年   23437篇
  1992年   85189篇
  1991年   81604篇
  1990年   78832篇
  1989年   76104篇
  1988年   69506篇
  1987年   68029篇
  1986年   63575篇
  1985年   60548篇
  1984年   44960篇
  1983年   37964篇
  1982年   22468篇
  1981年   19994篇
  1979年   38970篇
  1978年   27450篇
  1977年   23267篇
  1976年   21498篇
  1975年   22818篇
  1974年   26792篇
  1973年   25382篇
  1972年   23756篇
  1971年   21969篇
  1970年   20203篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
Occupational diseases Nos. 2108 and 2110 correspond to intervertebral disc-related diseases of the lumbar spine from many years of carrying or lifting heavy loads, occupations in extreme postures of full flexion or oscillation of the whole body when seated, and which compel the cessation of all activities which are or could be the cause for the origin, exacerbation or recurrence of the disease. These occupational diseases came into force at the start of 1993, but there have been considerable problems in their implementation. The present Part I of the contribution is the result of the work of an interdisciplinary study group and contains medical criteria for the assessment of possibly strain-related clinical characteristics and the evaluation of other possible causes. Part II is to be published in Volume 4/2005 and will deal with questions related to forced cessation and to the assessment of the loss of earning ability. Agreement was reached in many areas related to the assessment of occupational claims. This should allow for evidence-based decision making in the future for the occupational diseases Nos. 2108 and 2110.  相似文献   
995.
Multidetector-row computed tomography (MDCT) can be used to quantify morphological features and investigate structure/function relationship in COPD. This approach allows a phenotypical definition of COPD patients, and might improve our understanding of disease pathogenesis and suggest new therapeutical options. In recent years, magnetic resonance imaging (MRI) has also become potentially suitable for the assessment of ventilation, perfusion and respiratory mechanics. This review focuses on the established clinical applications of CT, and novel CT and MRI techniques, which may prove valuable in evaluating the structural and functional damage in COPD.  相似文献   
996.
997.
998.
Catecholaminergic polymorphic ventricular tachycardia is important to be diagnosed as an underlying disease in children with syncope and normal heart, because of its poor prognosis. CASE REPORT: A 3-year-old boy was referred for stress and emotion induced syncope. Primary ventricular arrhythmia, consisting of salvos of bidirectional ventricular tachycardia, was reproducibly induced by physical exertion. The syncopal events and severe arrhythmia disappeared with beta-blocking therapy. CONCLUSION: Despite its rare occurrence, catecholaminergic polymorphic ventricular tachycardia is an important cause of stress and emotion induced syncope and sudden death in children.  相似文献   
999.
We report the identification of a new transthyretin (TTR) gene mutation and variant protein, Glu61Gly, in a 55-year-old man with progressive cardiomyopathy, mild peripheral neuropathy and bilateral carpal tunnel syndrome. A diagnosis of TTR-associated familial amyloidosis (ATTR) was considered after an endomyocardial biopsy revealed amyloid deposits in the heart of a patient who had no family history of amyloidosis and no evidence of a plasma cell dyscrasia. Serum screening for a TTR variant by isoelectric focusing (IEF) was positive and prompted further studies to identify the genetic abnormality and to characterize the amyloidogenic protein. Direct DNA sequence analysis of all four coding regions in the TTR gene demonstrated heterozygosity in exon 3. Near equal amounts of guanine (G) and adenine (A) were observed at the second base position of codon 61. The wild-type (GAG) and mutated (GGG) sequences found in codon 61 correspond to glutamic acid (Glu) and glycine (Gly) residues, amino acids which differ in mass by -72 Da. Mass spectrometric analyses of TTR immunoprecipitated from serum showed the presence of both wild-type and variant proteins. The observed mass results for the wild-type and variant proteins were consistent with the predicted values calculated from the genetic analysis data.  相似文献   
1000.
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