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   1265277篇
  免费   94882篇
  国内免费   1586篇
耳鼻咽喉   16318篇
儿科学   41006篇
妇产科学   34970篇
基础医学   189529篇
口腔科学   34753篇
临床医学   117813篇
内科学   248185篇
皮肤病学   27285篇
神经病学   101921篇
特种医学   46804篇
外国民族医学   266篇
外科学   178711篇
综合类   25753篇
现状与发展   3篇
一般理论   568篇
预防医学   104747篇
眼科学   28045篇
药学   92609篇
  7篇
中国医学   2022篇
肿瘤学   70430篇
  2018年   13553篇
  2017年   10399篇
  2016年   11342篇
  2015年   13109篇
  2014年   18024篇
  2013年   27533篇
  2012年   37631篇
  2011年   40028篇
  2010年   23101篇
  2009年   22307篇
  2008年   37850篇
  2007年   40487篇
  2006年   40061篇
  2005年   39174篇
  2004年   37607篇
  2003年   36044篇
  2002年   34934篇
  2001年   56087篇
  2000年   57108篇
  1999年   48147篇
  1998年   13428篇
  1997年   12247篇
  1996年   12662篇
  1995年   11932篇
  1994年   11116篇
  1993年   10414篇
  1992年   38223篇
  1991年   37706篇
  1990年   36466篇
  1989年   35272篇
  1988年   32701篇
  1987年   32035篇
  1986年   30536篇
  1985年   28798篇
  1984年   21955篇
  1983年   19199篇
  1982年   11368篇
  1981年   10322篇
  1979年   20947篇
  1978年   15399篇
  1977年   12792篇
  1976年   11849篇
  1975年   12811篇
  1974年   15590篇
  1973年   15363篇
  1972年   14515篇
  1971年   13556篇
  1970年   12786篇
  1969年   12068篇
  1968年   11230篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
A case is presented which demonstrates the potential utility of the extracranial-intracranial bypass procedure for the treatment of vasospasm after subarachnoid hemorrhage. Extracranial-intracranial bypass surgery offers another alternative to the treatment of patients with vasospasm who have failed aggressive medical management.  相似文献   
112.
113.
The composition of the clientele from an ophthalmological practitioner's office is described with special reference to the occurrence of glaucoma and disc haemorrhages (h in singular; hh in plural). This study could not be planned as an epidemiological survey and gives no clue to sensitivity or specificity of hh in glaucoma. During a period of about 10 years ending with 1986 there were 731 patients with h and/or glaucoma. When detected, 185 patients had h but no glaucoma, 33 had both h and glaucoma and 513 had glaucoma but no h. During the follow-up period hh were detected in 83 cases of glaucoma, and glaucoma developed in 27 cases with hh. The detection rate of hh among glaucoma was low but steady, indicating that hh may occur at any stage of the glaucoma process. This study shows no predilection for hh in cases with general hypertension or diabetes, nor is the frequency of hh among pseudoexfoliation cases significantly lower than among cases without this stigma.  相似文献   
114.
Isotretinoin (Accutane Capsules) is a synthetic vitamin A compound used for treatment of recalcitrant cystic acne. It has numerous ocular toxic side effects which include anterior segment inflammation, dry eye syndrome, contact lens intolerance, altered refraction, photosensitivity, and reduced night vision. Eye care practitioners should be aware of these potential side effects and be prepared to communicate with the prescribing physician if side effects present.  相似文献   
115.
Summary A randomised crossover study was performed in subjects with rheumatoid arthritis (or other arthropathies) to investigate if any alteration in the steady pharmacokinetics of the NSAID piroxicam (a drug which is extensively metabolised via cytochrome P450) or its major metabolites occurred as a result of coadministering either cimetidine or nizatidine.Twelve females and 2 males with mean age, weight, and albumin concentrations of 58 years, 61 kg, and 40 g·L–1 respectively, completed the study. Comparisons were made between the following parameters: plasma piroxicam AUCs [AUC0-24(P)], plasma 5-hydroxypiroxicam AUCs [AUC0-24(5-OHP)], the ratio of these i.e. AUC0-24(5-OHP):AUC0-24(p), the % piroxicam daily dose excreted in urine as 5-hydroxypiroxicam (before and after glucuronidase incubation); and the mean of the steady state trough piroxicam, and 5-hydroxypiroxicam concentrations (obtained during each study phase in addition to the wash-out period).A statistically significant difference as a result of initiating either cimetidine or nizatidine was obtained only for the ratio AUC0-23(5-OHP):AUC0-24(P). This was indicative of a weak potential to inhibit piroxicam hydroxylation.No clinically significant alteration in the steady state pharmacokinetics of piroxicam occurred in these subjects as a result of cimetidine or nizatidine coadministration. Consequently it is unlikely that any adverse events would arise from these combinations.  相似文献   
116.
117.
. Neutrophil-mediated tissue damage has been implicated in the pathogenesis of diarrhoea-associated haemolytic uraemic syndrome (D+ HUS). This study evaluates priming and activation of the neutrophil oxidative burst in D+ HUS using chemiluminescent techniques. Peripheral blood neutrophils from 11 children with acute D+ HUS were examined. No difference was found in the oxidative burst of neutrophils from patients and controls. Serum elastase levels were measured in 8 patients and found to be significantly elevated. Although elastase results suggest neutrophil activation, chemiluminescence studies do not confirm this in the peripheral blood neutrophil. This does not support a significant role for circulating agents in priming and activating the peripheral blood neutrophil. Received August 17, 1995; received in revised form and accepted November 27, 1995  相似文献   
118.
E R Broun  A Greist  G Tricot  R Hoffman 《JAMA》1990,264(11):1441-1443
Two patients with sideroblastic anemia secondary to zinc-induced copper deficiency absorbed excess zinc secondary to oral ingestion. The source of excess zinc was a zinc supplement in one case; in the other, ingested coins. In each case, the sideroblastic anemia was corrected promptly after removal of the source of excess zinc. These two cases emphasize the importance of recognizing this clinical entity, since the myelodysplastic features are completely reversible.  相似文献   
119.
The role of caffeine or coffee in causing or promoting the incidence of serious disease is equivocal. Two design factors may account for the discrepancies in reported findings on the effects of coffee drinking: (a) imprecision of measurement and (b) confounding variables. A study of 2,714 white U.S. adults disclosed that, of 32 risk factors analyzed by linear and logistic regression, only sex and cigarette smoking were found to be important potential confounders of caffeine and coffee intake. Partial R2 values of the other 30 risk factors were relatively small and were inconsistent for each sex. It is unlikely that any of these factors could explain any of the reported associations between caffeine or coffee consumption and certain diseases. However, certain weak associations with caffeine or coffee intake should be included in the study design when they are known to be risk factors of a disease under investigation. These factors for men are dietary fat intake, vitamin C intake, and body mass index; and for women are vitamin use, alcohol intake, stress, and perceived health status.  相似文献   
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