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   3356篇
  免费   379篇
  国内免费   19篇
耳鼻咽喉   25篇
儿科学   137篇
妇产科学   66篇
基础医学   438篇
口腔科学   107篇
临床医学   447篇
内科学   616篇
皮肤病学   53篇
神经病学   284篇
特种医学   253篇
外科学   330篇
综合类   148篇
一般理论   1篇
预防医学   327篇
眼科学   77篇
药学   246篇
中国医学   2篇
肿瘤学   197篇
  2022年   39篇
  2021年   101篇
  2020年   53篇
  2019年   76篇
  2018年   89篇
  2017年   58篇
  2016年   54篇
  2015年   55篇
  2014年   75篇
  2013年   112篇
  2012年   158篇
  2011年   121篇
  2010年   79篇
  2009年   78篇
  2008年   133篇
  2007年   149篇
  2006年   112篇
  2005年   131篇
  2004年   111篇
  2003年   107篇
  2002年   103篇
  2001年   94篇
  2000年   96篇
  1999年   98篇
  1998年   52篇
  1997年   48篇
  1996年   62篇
  1995年   45篇
  1994年   46篇
  1993年   39篇
  1992年   63篇
  1991年   63篇
  1990年   72篇
  1989年   66篇
  1988年   68篇
  1987年   52篇
  1986年   60篇
  1985年   50篇
  1984年   49篇
  1983年   48篇
  1982年   36篇
  1980年   35篇
  1979年   39篇
  1978年   33篇
  1977年   29篇
  1971年   37篇
  1970年   29篇
  1969年   31篇
  1967年   28篇
  1966年   31篇
排序方式: 共有3754条查询结果,搜索用时 15 毫秒
11.
We describe the first cluster of cases of necrotizing fasciitis (NF) in this century in the United Kingdom (UK). Between 1 January and 30 June 1994 there were six cases (five confirmed, one probable) of Streptococcus pyogenes NF in west Gloucestershire, population 320,000. Two cases died. The first two patients probably acquired their infections during the course of elective surgery performed in the same operating theatre, possibly from a nasopharyngeal carrier amongst the theatre staff. The remaining infections were community-acquired. Of 5 S. pyogenes isolates there were 2 M1 strains, 1 M3, 1 M5 and 1 M non-typeable strain. S. pyogenes NF had not been recorded in west Gloucestershire in the preceding 10 years and the incidence of S. pyogenes bacteraemia in England and Wales had not risen in the past 5 years. The two presumably theatre-acquired infections raised several issues. The need for detailed bacteriological investigation of all cases of post-surgical NF was confirmed. Clusters of S. pyogenes infection following surgery should be managed by closure of the operating theatre until all staff have been screened for carriage. Closure of an operating theatre and screening of staff following a sporadic case is probably not justified because of the infrequency of surgical cross-infection with S. pyogenes. Regular, routine screening of theatre staff is neither practical nor necessary.  相似文献   
12.
Recent studies have suggested that cocaethylene, an active metabolite of cocaine found in blood and postmortem brain of individuals self-administering cocaine and alcohol, may play a role in the increased toxicity seen when coadministering these 2 drugs. We have used positron emission tomography (PET) and carbon-11 (t1/2:20.4 min) labeled cocaine and cocaethylene to compare the short-term kinetics of cocaine and cocaethylene in baboon brain. The regional uptake of [11C]cocaine cocaethylene in baboon brain. The regional uptake of [11C]cocaine ([11C]COC) and [11C]cocaethylene ([11C]CE), 5-8 mCi and 4-6 micrograms, in baboon brain (n = 7) were similar but clearance from whole brain (global, GL) and from striatum (SR), thalamus (TH), and cerebellum (CB) was slower for cocaethylene. Steady-state distribution volumes (DV) were not significantly different in the striatum but were greater for cocaethylene in the thalamus, cerebellum, and whole brain. Debenzoylation of cocaethylene proceeded at about one-third the rate of cocaine, as determined by in vitro incubation of labeled cocaethylene and labeled cocaine with baboon plasma and with purified horse butyryl-cholinesterase (EC 3.1.1.8). Even though the slower clearance of cocaethylene could lead to longer tissue exposures and potentially accentuated or different physiological effects relative to cocaine, the difference between the 2 drugs is not large. Thus it is more likely that the direct actions of cocaine and alcohol on some organs, rather than cocaethylene, account for this enhanced toxicity.  相似文献   
13.
14.
Time to reverse that altruism bypass...   总被引:3,自引:3,他引:0       下载免费PDF全文
  相似文献   
15.
16.
R Charnley  R F A Logan  P Moayyedi    S Travis 《Gut》2003,52(11):1653-1654
  相似文献   
17.
18.
Three patients with paralysed horizontal gaze are presented. Involuntary use of convergence to assist horizontal gaze was noted as a late feature. All patients showed (1) unilateral or bilateral horizontal gaze palsy (two patients had one and a half syndrome, the other had bilateral nuclear sixth nerve palsies), (2) adduction of both eyes on attempted gaze into the paralysed field, (3) miosis which coincided with adduction. Convergence substitution should be considered in the differential diagnosis of gaze induced strabismus.  相似文献   
19.
Ulcerative colitis (UC) and Crohn's disease (CD) are generally regarded as diseases of affluent societies of the Western World, although their frequency in less affluent areas is not well established. This retrospective study therefore, assesses the incidence of UC and CD in a semirural area of north west Greece during the 10 year period 1982-1991. By the 31 December 1991, 61 patients had met standard diagnostic criteria for UC (annual incidence 4.0/10(5), 95% confidence intervals 3.0 to 5.0/10(5)) and only five patients met the diagnostic criteria for CD (annual incidence 0.3/10(5), 95% confidence intervals 0.1 to 0.8/10(5)) in this area of 157,214 inhabitants. UC incidence was lowest in the first three years at 1.8/10(5) per annum and subsequently increased to 4.8 and 5.1/10(5) per annum for the successive four and three year periods respectively. UC incidence was slightly higher in men. A third of all cases of UC had pancolitis while a quarter had only proctitis. More than one half were categorised as having moderate or severe colitis. Three quarters of the patients resided in urban areas. The incidence of CD was a twelfth of the UC incidence, which is in considerable contrast with most Western countries where the incidence of CD is usually no less than a third that for UC. The rarity of CD points to the absence of aetiological environmental factors specific for CD.  相似文献   
20.
Laryngeal mask and fibreoptic tracheal intubation   总被引:2,自引:0,他引:2  
S. Logan  P. Charters 《Anaesthesia》1994,49(6):543-544
  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