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   21232篇
  免费   1475篇
  国内免费   97篇
耳鼻咽喉   228篇
儿科学   556篇
妇产科学   434篇
基础医学   3361篇
口腔科学   537篇
临床医学   2087篇
内科学   4651篇
皮肤病学   540篇
神经病学   2484篇
特种医学   630篇
外科学   1831篇
综合类   112篇
一般理论   13篇
预防医学   1839篇
眼科学   432篇
药学   1339篇
中国医学   78篇
肿瘤学   1652篇
  2024年   28篇
  2023年   190篇
  2022年   335篇
  2021年   694篇
  2020年   466篇
  2019年   658篇
  2018年   700篇
  2017年   535篇
  2016年   633篇
  2015年   745篇
  2014年   882篇
  2013年   1102篇
  2012年   1773篇
  2011年   1888篇
  2010年   1003篇
  2009年   909篇
  2008年   1481篇
  2007年   1480篇
  2006年   1393篇
  2005年   1304篇
  2004年   1212篇
  2003年   1089篇
  2002年   927篇
  2001年   112篇
  2000年   75篇
  1999年   119篇
  1998年   181篇
  1997年   154篇
  1996年   112篇
  1995年   88篇
  1994年   68篇
  1993年   49篇
  1992年   32篇
  1991年   34篇
  1990年   37篇
  1989年   25篇
  1988年   22篇
  1987年   30篇
  1986年   12篇
  1985年   20篇
  1984年   14篇
  1983年   18篇
  1982年   13篇
  1981年   11篇
  1980年   16篇
  1979年   19篇
  1978年   10篇
  1977年   11篇
  1974年   9篇
  1973年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Die Anaesthesiologie - Die Anlage einer Magensonde im OP oder auf einer Intensivstation (ITS) stellt eine alltäglich durchgeführte Prozedur dar. Obwohl die Sonde häufig durch...  相似文献   
2.
3.
4.
5.

Introduction

Little is known about dementia incidence in diverse populations of oldest-old, the age group with highest dementia incidence.

Methods

Incident dementia diagnoses from 1/1/2010 to 9/30/2015 were abstracted from medical records for 2350 members of an integrated health care system in California (n = 1702 whites, n = 375 blacks, n = 105 Latinos, n = 168 Asians) aged ≥90 in 2010. We estimated race/ethnicity-specific age-adjusted dementia incidence rates and implemented Cox proportional hazards models and Fine and Gray competing risk of death models adjusted for demographics and comorbidities in midlife and late-life.

Results

Dementia incidence rates (n = 771 cases) were lowest among Asians (89.9/1000 person-years), followed by whites (96.9/1000 person-years), Latinos (105.8/1000 person-years), and blacks (121.5/1000 person-years). Cox regression and competing risk models estimated 28% and 36% higher dementia risk for blacks versus whites adjusting for demographics and comorbidities.

Discussion

Patterns of racial/ethnic disparities in dementia seen in younger older adults continue after the age of 90 years, though smaller in magnitude.  相似文献   
6.
7.

Background

Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.

Methods

We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).

Results

Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.

Conclusions

Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation.  相似文献   
8.
9.
Studies on the exposure of children to sugar-sweetened beverages (SSBs) at an early age may contribute to better understand the common causes and the temporal order of the relationships between obesity and asthma in early childhood. The objective of this study was to estimate the association between SSB and child asthma traits in the 2nd year of life, modeling direct and indirect pathways mediated by the highest BMI-z of the child and allergic inflammation. Data from the BRISA cohort, São Luís-MA, Brazil (n = 1140), were obtained from the baseline and from the follow-up performed at the 2nd year of life. The main explanatory variable was the calories from added sugars in SSBs as a percentage of the total daily energy intake. The outcome child asthma traits was a latent variable deduced from four indicators: medical diagnosis of asthma, wheezing, emergency visit due to intense wheezing, and medical diagnosis of rhinitis. A high percentage of daily calories from sugars added to SSBs was directly associated with higher values of child asthma traits (standardized coefficient (SC = 0.073; P = .030)). High levels of eosinophils were also directly associated with child asthma traits (SC = 0.118; P = .049). No mediation pathways were observed via greater BMI-z or eosinophil counts. Therefore, early exposure of children to SSB may contribute to increased risk of childhood asthma, preceding the link between sugar consumption and overweight/obesity, not yet evident in children in the first 2 years of life.  相似文献   
10.
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