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   42880篇
  免费   3804篇
  国内免费   78篇
耳鼻咽喉   462篇
儿科学   1405篇
妇产科学   910篇
基础医学   5761篇
口腔科学   699篇
临床医学   4817篇
内科学   8461篇
皮肤病学   594篇
神经病学   3668篇
特种医学   1505篇
外国民族医学   4篇
外科学   5497篇
综合类   996篇
一般理论   25篇
预防医学   4487篇
眼科学   1566篇
药学   3057篇
中国医学   41篇
肿瘤学   2807篇
  2022年   233篇
  2021年   697篇
  2020年   452篇
  2019年   741篇
  2018年   812篇
  2017年   612篇
  2016年   684篇
  2015年   830篇
  2014年   1134篇
  2013年   1617篇
  2012年   2399篇
  2011年   2513篇
  2010年   1289篇
  2009年   1322篇
  2008年   2197篇
  2007年   2400篇
  2006年   2302篇
  2005年   2241篇
  2004年   2217篇
  2003年   1987篇
  2002年   1954篇
  2001年   987篇
  2000年   1044篇
  1999年   990篇
  1998年   535篇
  1997年   446篇
  1996年   415篇
  1995年   405篇
  1994年   364篇
  1993年   345篇
  1992年   709篇
  1991年   725篇
  1990年   684篇
  1989年   668篇
  1988年   590篇
  1987年   562篇
  1986年   599篇
  1985年   544篇
  1984年   447篇
  1983年   350篇
  1982年   309篇
  1981年   256篇
  1980年   256篇
  1979年   371篇
  1978年   285篇
  1977年   246篇
  1976年   217篇
  1975年   213篇
  1974年   249篇
  1973年   269篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
A case illustrating the potentially fatal complication of endogenous Gram Negative Aerobic Bacillus (GNAB) septicaemia secondary to nosocomial pneumonia is presented along with current theories as to its aetiology. The technique of selective decontamination of the digestive tract is designed and advocated to prevent such occurrences; oral and maxillofacial surgeons should be aware of this approach. It may be, however, that by using much simpler manoeuvres such as changes in policy regarding gastric stress ulcer prophylaxis, the already small risk of such an occurrence will be further reduced. Awareness of this condition will allow a higher index of suspicion when presented with catastrophic septic complications on the ITU and aid in more rational planning of antimicrobial therapy.  相似文献   
32.
. 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   
33.
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   
34.
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   
35.
36.
Aims: On the Edge is a mental health education programme designed to support early intervention by increasing knowledge and understanding of early psychosis, reducing the stigma associated with mental health issues and improving awareness of avenues of help. The target audience was young people aged 14–22 years in schools and colleges. Methods: An interactive drama programme was developed through collaborative working across psychiatry, applied drama and those with direct experience of psychosis. A national tour engaged 2500 students in 71 performances that took place in 51 schools and colleges. The programme was evaluated against its aims with data collected both during and after the tour. Results: Quantitative and qualitative evaluation found significant gains with respect to all three aims. Thirty‐one schools developed supportive links with local mental health services. Conclusions: This programme shows the value and effectiveness of delivering health education on early psychosis through the medium of applied drama, and offers a model for a programme that can be incorporated into early intervention services. Lessons learned through delivering this programme are a valuable contribution towards future developments of mental health education programmes for schools.  相似文献   
37.
38.
Heart failure is reaching epidemic proportions in the United States, causing a constellation of disabling symptoms. Cognitive impairment in people with heart failure may be more common than previously known with multiple etiologies from both the disease process and the treatment. Exemplars from a research study are used to illustrate the perspective of heart failure patients. Given the critical importance of memory deficits on patient education, potential nursing interventions to address the issue of cognitive impairment are described.  相似文献   
39.
40.
ObjectiveWe examine remission rate probabilities, recovery rates, and residual symptoms across 36 weeks in the Treatment for Adolescents with Depression Study (TADS).MethodThe TADS, a multisite clinical trial, randomized 439 adolescents with major depressive disorder to 12 weeks of treatment with fluoxetine, cognitive–behavioral therapy, their combination, or pill placebo. The pill placebo group, treated openly after week 12, was not included in the subsequent analyses. Treatment differences in remission rates and probabilities of remission over time are compared. Recovery rates in remitters at weeks 12 (acute phase remitters) and 18 (continuation phase remitters) are summarized. We also examined whether residual symptoms at the end of 12 weeks of acute treatment predicted later remission.ResultsAt week 36, the estimated remission rates for intention-to-treat cases were as follows: combination, 60%; fluoxetine, 55%; cognitive–behavioral therapy, 64%; and overall, 60%. Paired comparisons reveal that, at week 24, all active treatments converge on remission outcomes. The recovery rate at week 36 was 65% for acute phase remitters and 71% for continuation phase remitters, with no significant between-treatment differences in recovery rates. Residual symptoms at the end of acute treatment predicted failure to achieve remission at weeks 18 and 36.ConclusionsMost depressed adolescents in all three treatment modalities achieved remission at the end of 9 months of treatment.  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