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   1387209篇
  免费   116127篇
  国内免费   6471篇
耳鼻咽喉   17431篇
儿科学   44234篇
妇产科学   37377篇
基础医学   189605篇
口腔科学   37169篇
临床医学   126418篇
内科学   287512篇
皮肤病学   32526篇
神经病学   115020篇
特种医学   57364篇
外国民族医学   276篇
外科学   218290篇
综合类   32400篇
现状与发展   3篇
一般理论   453篇
预防医学   110935篇
眼科学   29237篇
药学   97328篇
  6篇
中国医学   2306篇
肿瘤学   73917篇
  2018年   14712篇
  2017年   11619篇
  2016年   13796篇
  2015年   15501篇
  2014年   21676篇
  2013年   32065篇
  2012年   39696篇
  2011年   42563篇
  2010年   26415篇
  2009年   25667篇
  2008年   39416篇
  2007年   42168篇
  2006年   43155篇
  2005年   41577篇
  2004年   39466篇
  2003年   38483篇
  2002年   36241篇
  2001年   66630篇
  2000年   68385篇
  1999年   57104篇
  1998年   17212篇
  1997年   15380篇
  1996年   16337篇
  1995年   16544篇
  1994年   15349篇
  1993年   14379篇
  1992年   47396篇
  1991年   46018篇
  1990年   44278篇
  1989年   42119篇
  1988年   39021篇
  1987年   38322篇
  1986年   36089篇
  1985年   34885篇
  1984年   26620篇
  1983年   22318篇
  1982年   14075篇
  1981年   12637篇
  1980年   11918篇
  1979年   23708篇
  1978年   17236篇
  1977年   14524篇
  1976年   13320篇
  1975年   13842篇
  1974年   16212篇
  1973年   15505篇
  1972年   14275篇
  1971年   13122篇
  1970年   11968篇
  1969年   11175篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
LUMBOVERTEBRAL SYNDROME AFTER EXTRADURAL BLOOD PATCH   总被引:2,自引:1,他引:1  
We describe a patient who developed an immobilizing lumbovertebralsyndrome after an extradural blood patch and who was hospitalizedwith a. suspected extradural abscess. An infectious aetiologyof the persistent backache could be excluded and the patientrecovered with analgesics and physiotherapy. The probable aetiologyis discussed.  相似文献   
112.
113.
114.
Fetal B lymphocytes in mice and humans use a limited number of the available VH gene segments. Mouse fetal B cells primarily utilize 3' VH elements, suggesting that the localization of these elements determines their rearrangement frequency. The previously reported non-random usage of human VH genes has been more difficult to explain. In this study the authors analysed the expression of the most proximal 3' human VH element (VH6) using a monoclonal antibody (JE-6). VH6 expression was assessed in various B cell differentiation stages from fetal liver, bone marrow and spleen at 12–20 weeks of gestation. The authors demonstrate that the level of VH6 expression does not exceed a stochastic usage frequency. This suggests that the localization of VH6 does not significantly promote its expression during human fetal life, and that other factors must affect the usage of VH genes during human fetal development.  相似文献   
115.
116.
A case-control study of squamous cell carcinoma of the upper aerodigestive tract conducted in Heidelberg and Giessen (FRG) provided information on occupational factors in 200 patients and 800 controls (adjusted to sex, age and area of living; 4:1 matched design). The number of subjects exposed to wood dusts, organic chemicals, coal products or to cement was significantly elevated in the tumour group. An increased risk for head and neck cancer was observed after exposition to wood dust (RR = 2,2), organic compounds (RR = 2,4), coal products (RR = 2,7) and especially to cement (RR = 4,4). The cancer risk due to cement exposition showed a positive correlation to the duration of exposition and remained significantly elevated after adjustment for alcohol and tobacco consumption.  相似文献   
117.
Facial reanimation after acoustic neuroma excision is currently accomplished using a variety of surgical techniques. A multi-institutional survey of patient perceptions of facial reanimation success was accomplished by mailing a questionnaire to 809 randomly selected members of the Acoustic Neuroma Association. Four hundred sixty patients who underwent 296 reanimation procedures responded. Facial to hypoglossal nerve anastomosis, tarsorrhaphy, and upper eyelid implants were most frequently performed. The patient's estimations of initial deficit, spontaneous recovery, and overall satisfaction with the reanimation procedures are discussed.  相似文献   
118.
Background : The clinical course of chronic hepatitis B is variable. Patients with hepatic decompensation, bridging necrosis or an alpha-fetoprotein level greater than 100 ng/mL during an exacerbation of hepatitis have a high risk of developing cirrhosis. This study was conducted to evaluate the effect of colchicine in the prevention of cirrhosis in such patients.
Methods : Patients with risk factor(s) were randomized to receive either colchicine 5 mg/week or no specific treatment, the end point being development of cirrhosis.
Results : After a follow up period of 4 years, the treatment group had a marked reduction in exacerbations of acute hepatitis (32% vs. 63%/patient/year, P <0.005). Seven out of 38 patients in the treatment group and 10 out of 27 patients in the control group developed cirrhosis. The calculated cumulative incidence of cirrhosis by the end of first, second, third and fourth years in the treatment group was 8.7, 18.6, 32 and 32%, respectively. The corresponding figures in the control group were 30, 35.5, 46.3 and 73.2%, respectively, with a P -value of 0.057.
Conclusions : The results suggest that colchicine may prevent cirrhosis in chronic hepatitis B patients with risk factor(s), possibly by suppressing exacerbations of hepatitis through an anti-inflammatory effect.  相似文献   
119.
120.
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