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   541393篇
  免费   28423篇
  国内免费   588篇
耳鼻咽喉   6792篇
儿科学   17182篇
妇产科学   12955篇
基础医学   94111篇
口腔科学   12725篇
临床医学   49537篇
内科学   97927篇
皮肤病学   12052篇
神经病学   34935篇
特种医学   20140篇
外国民族医学   56篇
外科学   79909篇
综合类   7851篇
现状与发展   2篇
一般理论   111篇
预防医学   39141篇
眼科学   12054篇
药学   42029篇
  2篇
中国医学   1172篇
肿瘤学   29721篇
  2021年   4231篇
  2019年   4137篇
  2018年   6035篇
  2017年   4340篇
  2016年   5126篇
  2015年   5651篇
  2014年   7491篇
  2013年   10992篇
  2012年   16378篇
  2011年   18166篇
  2010年   10394篇
  2009年   9194篇
  2008年   16350篇
  2007年   18142篇
  2006年   17541篇
  2005年   16870篇
  2004年   16479篇
  2003年   15776篇
  2002年   15288篇
  2001年   22759篇
  2000年   23286篇
  1999年   19235篇
  1998年   5338篇
  1997年   4472篇
  1996年   4472篇
  1995年   4183篇
  1992年   14569篇
  1991年   15964篇
  1990年   16066篇
  1989年   15760篇
  1988年   14387篇
  1987年   14312篇
  1986年   13250篇
  1985年   12739篇
  1984年   9454篇
  1983年   8042篇
  1982年   4202篇
  1979年   8979篇
  1978年   6402篇
  1977年   5167篇
  1976年   5531篇
  1975年   6633篇
  1974年   7447篇
  1973年   7178篇
  1972年   6621篇
  1971年   6330篇
  1970年   5898篇
  1969年   5481篇
  1968年   5165篇
  1967年   4633篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
74.
Background: The management and follow-up of asthma patients presenting at Accident and Emergency (A&E) departments have mostly been studied in children's hospitals or specialised teaching hospitals. Aims: To study the adequacy of assessment, treatment and follow-up of patients presenting at A&E departments in non-teaching hospitals. Methods: A twenty-five per cent sample of presentations to A&E departments in all public hospitals in the Illawarra for one year was selected for a case note audit. Information on demographics, assessment, management and referral was extracted from the A&E case notes and medical records of cases with documentation of a final diagnosis of asthma. Chi square and Fischer's Exact tests were used for comparisons among hospitals. Results: Of 359 presentations with a final diagnosis of asthma, 88% were self referred and only 5% were first presentations. Objective measures of airways obstruction was not documented in 34% of admissions and 48% of nonadmissions. There was no documented follow-up in 28% of cases. The assessment and management of asthma in A&E was significantly poorer in smaller hospitals. Conclusion: Evidence of high use of A&E as a primary care facility by asthma patients was found in the study. There is a need to implement protocols to optimise assessment and treatment of asthma in smaller hospitals. (Aust NZ J Med 1993; 23: 672–677.).  相似文献   
75.
Felty's syndrome (FS), the association of rheumatoid arthritis (RA) and idiopathic neutropenia, remains an unexplained phenomenon. HLA-DR4 is found in over 90% of cases. Patients with FS may have a T cell lymphocytosis of CD3+CD8+CD57+ large granular lymphocytes (LGL syndrome). In this study of 47 patients with FS, 19% had clear evidence for LGL expansions, while in total 42% had variable evidence for the LGL syndrome using currently available techniques. Of these T cell expansions, 76% were clonal, as demonstrated by Southern blotting and analysis with T cell receptor (TCR) beta chain constant region probes. This technique may fail to detect clonal populations in some patients. Cytofluorographic analysis using antibodies specific for TCR V beta chains identified patients with clonal LGL expansions with results comparable to those obtained with Southern blotting. No evidence for shared V beta usage among expansions from different patients was seen. The role of LGL in RA and FS is currently unclear, but this technique offers a practical and accessible means of identifying patients with LGL expansions, as a starting point for further investigation.  相似文献   
76.
Case report 506   总被引:1,自引:0,他引:1  
  相似文献   
77.
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   
78.
79.
In the isolated perfused rat pancreas, D,L-difluoromethylornithine, tested at a concentration of 3 mmol/L, failed to affect the release of glucagon and insulin caused, over 15 min stimulation, by either L-arginine or L-ornithine (2.0, 5.0 or 10.0 mmol/L) in the presence of either 3.3 or 5.6 mmol/L D-glucose. The inhibition of ornithine decarboxylase also failed to affect the release of glucagon provoked by either L-leucine (2 or 3 mmol/L) or L-glutamine (2 mmol/L) and the secretion of insulin stimulated by a rise in glucose concentration from 5.6 to 10.6 mmol/L. These data are interpreted to suggest that the rapid generation of polyamines from either L-arginine or L-ornithine does not play any significant role in the immediate glucagonotropic and insulinotropic action of these cationic amino acids.  相似文献   
80.
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