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   47029篇
  免费   2519篇
  国内免费   247篇
耳鼻咽喉   470篇
儿科学   1011篇
妇产科学   1092篇
基础医学   5858篇
口腔科学   2857篇
临床医学   3349篇
内科学   12252篇
皮肤病学   1246篇
神经病学   3843篇
特种医学   849篇
外科学   7129篇
综合类   295篇
一般理论   6篇
预防医学   3538篇
眼科学   837篇
药学   2394篇
中国医学   225篇
肿瘤学   2544篇
  2023年   329篇
  2022年   650篇
  2021年   1626篇
  2020年   848篇
  2019年   1539篇
  2018年   1761篇
  2017年   1079篇
  2016年   1098篇
  2015年   1376篇
  2014年   1962篇
  2013年   2462篇
  2012年   3931篇
  2011年   4094篇
  2010年   2356篇
  2009年   1990篇
  2008年   3222篇
  2007年   3437篇
  2006年   3008篇
  2005年   2693篇
  2004年   2379篇
  2003年   2162篇
  2002年   2060篇
  2001年   341篇
  2000年   272篇
  1999年   290篇
  1998年   312篇
  1997年   257篇
  1996年   233篇
  1995年   185篇
  1994年   165篇
  1993年   135篇
  1992年   130篇
  1991年   98篇
  1990年   93篇
  1989年   74篇
  1988年   90篇
  1987年   65篇
  1986年   52篇
  1985年   78篇
  1984年   78篇
  1983年   69篇
  1982年   64篇
  1981年   77篇
  1980年   65篇
  1979年   45篇
  1978年   38篇
  1977年   52篇
  1976年   40篇
  1975年   37篇
  1974年   29篇
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
71.
72.
The aim was to determine whether the immunogenicity of an investigational hepatitis B vaccine (spHB) is at least as high as that of a licensed control vaccine, Engerix B®, and to evaluate its safety before inclusion in new pediatric combination vaccines. Two randomized, controlled, blind-observer, Phase 3 trials were performed: one in Argentina (344 participants aged 10–15 years, 10 μg HBsAg/dose) and one in Uruguay (344 participants aged 16–45 years, 20 μg HBsAg/dose). Both vaccines were given in a 0, 1, 6 month schedule to all participants with a baseline anti-Hep B antibody titer <0.6 mIU/mL. Antibody titers were measured pre-dose 1, 1 month after dose 2, pre-dose 3, and 1 month after dose 3. Statistical non-inferiority analyses were performed on seroprotection rates (SP) post-dose 3 (% with anti-Hep B titers ≥10 mIU/mL; delta non-inferiority limit of −10%). In both studies, SP for the spHB vaccine was 100% and the spHB vaccine was non-inferior in terms of SP to the licensed control vaccine. GMTs post-dose 3 were approximately 1.8- and 4.1-fold higher for spHB in the 10–15 year and 16–45 year age groups, respectively. Reactogenicity was low for each vaccine, after each dose. This highly immunogenic hepatitis B candidate vaccine was selected for further investigation as a component of new pediatric combination vaccines.  相似文献   
73.
74.
75.
Introduction and objectiveWhen sleep apnea-hypopnea syndrome (SAHS) and cardiovascular disease occur concurrently, prognosis is affected. Echocardiography can detect structural cardiac abnormalities but using this technique in all patients would place a heavy burden on resources. The objective of this study was to investigate whether the N-terminal fraction of brain natriuretic peptide (NT-proBNP) can be used as a marker for silent heart disease.Patients and methodsNT-proBNP concentration was measured in the 114 consecutive patients with SAHS who underwent echocardiography before starting treatment. Left and right ventricular systolic and diastolic function, as well as structural abnormalities, were studied. Correlations between NT-proBNP concentration and the abnormalities detected were investigated. A receiver operating characteristics (ROC) curve was plotted for NT-proBNP concentration and cardiac abnormalities.ResultsData for 98 patients were finally analyzed. NT-proBNP concentration was significantly correlated with ventricular septal thickness (r=0.63), posterior wall thickness (r=0.45), and left ventricular enddiastolic diameter (r=0.51) (P<.0001 for all correlations). The area under the ROC curve was significant (0.870; 95% confidence interval, 0.801-0.939; P<.0001). Assuming that specificity would be more useful for clinical practice, we calculated that NT-proBNP concentrations below 100 and 200 pg/mL could rule out structural abnormalities with a reliability of 90% and 100%, respectively.ConclusionsNT-proBNP concentration was strongly correlated with echocardiographic abnormalities and so could be a useful tool for identifying patients who should be referred to the cardiologist.  相似文献   
76.
IntroductionTo analyse the effectiveness and safety of the indwelling pleural catheter in the management of recurrent malignant pleural effusion.Patients and methodsA prospective multicentre study was performed in 63 consecutive outpatients from four Spanish hospitals. A total of 43 men and 20 women were included, with a median age of 67 years. In seven of the cases treatment with pleurodesis had failed; in five other cases their lung was trapped; in another five cases after repeat therapeutic thoracocentesis, and the rest of them as a preference choice to pleurodesis. All patients had an indwelling pleural catheter inserted (PleurX®, Denver Biomedical).ResultsMost of patients (94.5%) reported an improvement in their respiratory symptoms (cough and dyspnoea) and their ability to function independently. Average length of the catheterisation was 45 days (6-222). Average amount of drained pleural effusion was 75 ml, with a frequency of drainage of between 3 and 4 times per week and once fortnightly. Spontaneous pleurodesis was achieved following 34.9% of procedures. No complications occurred during the insertion of the catheter. The post-catheterisation complications were empyema (3 cases), chest pain (2 cases), and tumour metastasis (3 cases).ConclusionsThe use of an indwelling pleural catheter is an effective palliative treatment in the outpatient management for patients suffering malignant pleural effusion. It is also a simple treatment that can be easily applied, does not require hospitalisation and can be easily managed by the patient at home, with a low rate of complications.  相似文献   
77.
78.
The authors present a synthesis of the proposals put forth by the health sector of Venezuela during the framing of the new Venezuelan Constitution. They summarize the background to the National Constituent Assembly and the legal framework typical of the health sector at that time, identify the methodological aspects that substantiated the health topics included in the new Constitution, and analyze the articles that shape the current constitutional health framework in Venezuela, summarizing their most important features and comparing them with neoliberal health proposals.  相似文献   
79.
80.
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