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   37228篇
  免费   3000篇
  国内免费   71篇
耳鼻咽喉   353篇
儿科学   1301篇
妇产科学   870篇
基础医学   4997篇
口腔科学   509篇
临床医学   4901篇
内科学   6965篇
皮肤病学   469篇
神经病学   3251篇
特种医学   900篇
外国民族医学   4篇
外科学   3834篇
综合类   1043篇
一般理论   50篇
预防医学   4685篇
眼科学   1034篇
药学   2454篇
中国医学   30篇
肿瘤学   2649篇
  2023年   168篇
  2022年   275篇
  2021年   621篇
  2020年   436篇
  2019年   664篇
  2018年   684篇
  2017年   514篇
  2016年   642篇
  2015年   773篇
  2014年   1032篇
  2013年   1596篇
  2012年   2359篇
  2011年   2516篇
  2010年   1200篇
  2009年   1205篇
  2008年   2120篇
  2007年   2400篇
  2006年   2283篇
  2005年   2312篇
  2004年   2280篇
  2003年   2052篇
  2002年   1996篇
  2001年   574篇
  2000年   566篇
  1999年   619篇
  1998年   502篇
  1997年   407篇
  1996年   404篇
  1995年   365篇
  1994年   304篇
  1993年   266篇
  1992年   387篇
  1991年   380篇
  1990年   375篇
  1989年   363篇
  1988年   338篇
  1987年   295篇
  1986年   336篇
  1985年   295篇
  1984年   277篇
  1983年   230篇
  1982年   228篇
  1981年   209篇
  1980年   199篇
  1979年   257篇
  1978年   191篇
  1977年   157篇
  1976年   147篇
  1974年   154篇
  1973年   155篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
AIMS: To establish all-cause and cause-specific death rates, and risk factors for mortality in insulin-treated diabetic individuals living in the province of Canterbury, New Zealand. METHODS: Insulin-treated diabetic subjects (n = 995) on the Canterbury Diabetes Registry were followed up over 15 years and vital status determined. Death rates were standardized and hazard regression was used to model the effects of demographic covariates on relative survival time. RESULTS: There were 419 deaths in 11 226.3 person-years of follow-up with a standardized mortality ratio (SMR) of 2.0 (95% confidence interval (CI) 1.8-2.2). Relative mortality was greatest for the group aged 0-29 years (SMR 3.0 (95% CI 2.4-3.7)). After controlling for diabetes duration and gender, a 10-year increment in age of onset was associated with a 33% decrease in relative hazard (95% CI 29-36%), indicating that excess mortality due to diabetes declines with rising age of onset. After controlling for age of onset and gender, each 10-year increment in duration of diabetes is associated with a 26% decrease in relative hazard (95% CI 24-29%), indicating that with longer survival the mortality hazard approaches the general population hazard. Relative mortalities were increased for cardiovascular, renal and respiratory disease, but not malignancy. Relative mortality from acute metabolic complications was increased in the subgroup with age of onset of diabetes < 30 years and requiring insulin within 1 year of diagnosis. CONCLUSIONS: Mortality rates are high for insulin-treated diabetic individuals relative to the general population.  相似文献   
22.
23.
24.
25.
. 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   
26.
Disruption of neuromuscular contact by nerve-crush during the early postnatal period causes increased activity and abnormal reflex responses in affected motoneurons, but such changes are not found after nerve-crush in adult animals. We found previously that neonatally lesioned cells develop an abnormal dendritic field, which may explain the functional changes. Here we have studied the dendritic morphology of the same motoneuron pool after nerve-crush at maturity in order to correlate the observed alterations in morphology with physiological findings. One to two months after sciatic nerve-crush in adult animals, motoneurons supplying the extensor hallucis longus muscles of the rat were retrogradely labelled with cholera toxin subunit-B conjugated to horseradish peroxidase. The dendritic tree of labelled cells was then analysed. Following adult nerve-crush, the dendritic tree of the motoneurons was smaller but did not display the localised increase in dendritic density seen after neonatal nerve-crush. These findings support the view that such specific morphological changes contribute to the physiological abnormalities seen only after neonatal nerve injury.  相似文献   
27.
This paper reports an inter-rater reliability study on the Functional Independence Measure (FIM). The FIM measures inpatient burden of care, as reflected in 18 self care items, rated on a seven point scale from dependent to independent. The subjects were 40 occupational therapists, divided according to experience with the FIM and randomly assigned to a FIM training or non-training group. Subjects rated video tapes of four stroke patients on transfers, bathing, dressing, grooming, toileting and eating items from the FIM. Rater consensus was calculated using the intraclass correlation coefficient (ICC), percentage agreement and a measure of disagreement. Rating accuracy was measured by comparisons with an expert rater. Ratings were most reliable when done by clinicians with no prior FIM experience, from the FIM training group. It is strongly recommended that all clinicians undergo FIM training before using this tool to ensure acceptable reliability.  相似文献   
28.
Occurrence of C. pylori infection of mucosa outside of the stomach might provide an ideal opportunity to examine C. pylori-mucosal interactions apart from the effects of acid and pepsin. Techniques previously used to examine Barrett's epithelium (for example, special mucin stains or scanning and transmission electron microscopy) might be particularly useful for exploration of new associations and formulation of new hypotheses. Whether C. pylori has a role in development of Barrett's ulcer or adenocarcinoma as a complication of Barrett's esophagus remains unanswered. Most of the current data about C. pylori are primarily observational; further studies are needed for clarification of important microbegut interactions.  相似文献   
29.
30.
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