收费全文 | 34661篇 |
免费 | 2734篇 |
国内免费 | 126篇 |
耳鼻咽喉 | 341篇 |
儿科学 | 1360篇 |
妇产科学 | 1023篇 |
基础医学 | 4731篇 |
口腔科学 | 435篇 |
临床医学 | 4465篇 |
内科学 | 6733篇 |
皮肤病学 | 687篇 |
神经病学 | 3776篇 |
特种医学 | 758篇 |
外科学 | 3435篇 |
综合类 | 368篇 |
现状与发展 | 1篇 |
一般理论 | 32篇 |
预防医学 | 3978篇 |
眼科学 | 587篇 |
药学 | 2078篇 |
中国医学 | 65篇 |
肿瘤学 | 2668篇 |
2024年 | 40篇 |
2023年 | 265篇 |
2022年 | 487篇 |
2021年 | 966篇 |
2020年 | 628篇 |
2019年 | 1057篇 |
2018年 | 1136篇 |
2017年 | 819篇 |
2016年 | 939篇 |
2015年 | 996篇 |
2014年 | 1341篇 |
2013年 | 1960篇 |
2012年 | 2776篇 |
2011年 | 2831篇 |
2010年 | 1655篇 |
2009年 | 1343篇 |
2008年 | 2270篇 |
2007年 | 2446篇 |
2006年 | 2352篇 |
2005年 | 2230篇 |
2004年 | 1979篇 |
2003年 | 1850篇 |
2002年 | 1766篇 |
2001年 | 268篇 |
2000年 | 216篇 |
1999年 | 246篇 |
1998年 | 343篇 |
1997年 | 291篇 |
1996年 | 227篇 |
1995年 | 198篇 |
1994年 | 161篇 |
1993年 | 193篇 |
1992年 | 117篇 |
1991年 | 98篇 |
1990年 | 76篇 |
1989年 | 75篇 |
1988年 | 89篇 |
1987年 | 52篇 |
1986年 | 58篇 |
1985年 | 45篇 |
1984年 | 62篇 |
1983年 | 60篇 |
1982年 | 57篇 |
1981年 | 56篇 |
1980年 | 57篇 |
1979年 | 36篇 |
1978年 | 41篇 |
1977年 | 32篇 |
1975年 | 20篇 |
1973年 | 21篇 |
Areas covered: This narrative review examines the current state of pharmacovigilance for biologics in the European Union (EU) and discusses relevant information on pharmacovigilance of biosimilars, the current EU pharmacovigilance system, and areas that could be improved.
Expert opinion: Although steps have been taken to improve pharmacovigilance of biologics in the EU, several enhancements can still be made, including additional training for healthcare professionals on ADR reporting, the use of 2D barcodes that enhance traceability, and an open discussion of potentially missed opportunities in the pharmacovigilance of biosimilars. 相似文献
Objective
Successful weight loss interventions for African-Americans adolescents are lacking. Cognitive-behavioral interventions seek to develop weight loss skills (e.g., counting calories, goal setting, managing one's environment). Little is known about how well adolescents implement such skills in their daily lives. Study aims were to (1) examine weight loss skills utilization at midpoint and end of a 6-month cognitive-behavioral/motivational interviewing weight loss sequential multiple assignment randomized trial (SMART), and (2) determine if greater skill utilization predicted weight loss at treatment end and 3 months post-treatment.Method
One hundred and eighty six African-Americans adolescents with obesity and their caregiver were first randomly assigned to complete 3 months of cognitive-behavioral and motivational interviewing family-based weight loss treatment in their home or in the research office (Phase 1). Nonresponders (i.e., those who lost < 3% of initial weight, n?=?161) were rerandomized to 3 months of continued skills training (n?=?83) or contingency management (n?=?78) for Phase 2; responders were allocated to 3 months of relapse prevention (n?=?20). Adolescents’ frequency of weight loss skills utilization was assessed via questionnaire at treatment midpoint and end.Results
Higher treatment attendance was associated with better skill utilization. Higher skill utilization was associated with more weight loss at treatment end, whereas higher baseline confidence was associated with more weight loss at follow-up.Conclusions
This study indicates the importance of attending weight loss intervention sessions to develop and strengthen weight loss skills in African-American adolescents with obesity, and strengthening confidence to use such skills for continued weight loss. 相似文献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![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)