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   4280篇
  免费   446篇
  国内免费   6篇
耳鼻咽喉   56篇
儿科学   85篇
妇产科学   160篇
基础医学   708篇
口腔科学   106篇
临床医学   359篇
内科学   734篇
皮肤病学   48篇
神经病学   432篇
特种医学   225篇
外科学   669篇
综合类   57篇
预防医学   489篇
眼科学   54篇
药学   325篇
中国医学   1篇
肿瘤学   224篇
  2022年   22篇
  2021年   83篇
  2020年   41篇
  2019年   63篇
  2018年   83篇
  2017年   63篇
  2016年   67篇
  2015年   71篇
  2014年   112篇
  2013年   188篇
  2012年   216篇
  2011年   256篇
  2010年   128篇
  2009年   119篇
  2008年   196篇
  2007年   208篇
  2006年   211篇
  2005年   174篇
  2004年   209篇
  2003年   145篇
  2002年   141篇
  2001年   150篇
  2000年   154篇
  1999年   127篇
  1998年   46篇
  1997年   47篇
  1996年   61篇
  1995年   45篇
  1994年   39篇
  1993年   41篇
  1992年   89篇
  1991年   86篇
  1990年   85篇
  1989年   76篇
  1988年   64篇
  1987年   65篇
  1986年   51篇
  1985年   54篇
  1984年   39篇
  1983年   38篇
  1982年   27篇
  1980年   24篇
  1979年   41篇
  1978年   39篇
  1977年   22篇
  1976年   24篇
  1975年   23篇
  1974年   28篇
  1973年   25篇
  1971年   26篇
排序方式: 共有4732条查询结果,搜索用时 46 毫秒
1.
Over 36 million people worldwide are infected with HIV. Antiretroviral therapy (ART) has proven to be highly effective to prevent HIV-1 transmission, clinical progression and death. Despite this success, the number of HIV-1 infected individuals continues increasing and ART should be taken for life. Therefore, there are two main priorities: the development of preventive vaccines to protect from HIV acquisition and achieve an efficient control of HIV infection in the absence of ART (functional cure). In this sense, in the last few years, there has been a broad interest in new and innovative approaches such as mRNA-based vaccines. RNA-based immunogens represent a promising alternative to conventional vaccines because of their high potency, capacity for rapid development and potential for low-cost manufacture and safe administration. Some mRNA-based vaccines platforms against infectious diseases have demonstrated encouraging results in animal models and humans. However, their application is still limited because the instability and inefficient in vivo delivery of mRNA. Immunogens, design, immunogenicity, chemical modifications on the molecule or the vaccine delivery methods are all crucial interventions for improvement. In this review we, will present the current knowledge and challenges in this research field. mRNA vaccines hold great promises as part of a combined strategy, for achieving HIV functional cure.  相似文献   
2.
OBJECTIVE: To evaluate variations in prenatal care quality by public and private clinical settings and by household wealth. DESIGN: The study uses 2003 data detailing retrospective reports of 12 prenatal care procedures received that correspond to clinical guidelines. The 12 procedures are summed up, and prenatal care quality is described as the average procedures received by clinical setting, provider qualifications, and household wealth. SETTING: Low-income communities in 17 states in urban Mexico. PARTICIPANTS: A total of 1253 women of reproductive age who received prenatal care within 1 year of the survey. MAIN OUTCOME MEASURE: The mean of the 12 prenatal care procedures received, reported as unadjusted and adjusted for individual, household, and community characteristics. RESULTS: Women received significantly more procedures in public clinical settings [80.7, 95% confidence interval (CI) = 79.3-82.1; P < or = 0.05] compared with private (60.2, 95% CI = 57.8-62.7; P < or = 0.05). Within private clinical settings, an increase in household wealth is associated with an increase in procedures received. Care from medical doctors is associated with significantly more procedures (78.8, 95% CI = 77.5-80.1; P < or = 0.05) compared with non-medical doctors (50.3, 95% CI = 46.7-53.9; P < or = 0.05). These differences are independent of individual, household, and community characteristics that affect health-seeking behavior. CONCLUSIONS: Significant differences in prenatal care quality exist across clinical settings, provider qualifications, and household wealth in urban Mexico. Strategies to improve quality include quality reporting, training, accreditation, regulation, and franchising.  相似文献   
3.
The morbidity and mortality conference (M&MC) appears to have sprung from the efforts of physicians to improve practice through the examination of medical errors and bad outcomes. The modern M&MC has had limited examination (and almost none outside surgery and anesthesia), but may be straying from the precepts from which it evolved. Learning from one's errors is important, but confronting them is difficult and is particularly delicate when done in conference. If the effort is successful, it can serve as a model. If unsuccessful, it can instead convey the lesson that attempting to learn from error is at best unproductive and at worst unpleasant. Thus, the M&MC is a double-edged sword, and particular attention should be given to the way that it is conducted. The authors review the historical roots and current literature on the M&MC, discusses relevant literature on medical error, and offers a definition, guiding principles, and a set of guidelines for a modern internal medicine M&MC. The ideas are presented not as a blueprint, but rather to stimulate a debate on the merits of establishing a framework for a working model, in order to refocus on the tradition of self-analysis and critical thinking in a manner that is productive for all participants.  相似文献   
4.
5.
The pattern evoked electroretinogram (PERG) was investigated in 11 patients with unilateral optic nerve disease and in a series of age-matched controls. The visually evoked potential (VEP) was also measured. The PERG showed a similar reduction to the VEP in optic nerve disease. Serial studies indicate that the PERG may not be affected immediately in some instances but may show a gradual decline over several months.  相似文献   
6.
7.
8.
LYMPHOGRANULOMA VENEREUM   总被引:3,自引:0,他引:3  
  相似文献   
9.
10.
1. The pharmacokinetics of gamma-glutamyl-L-dopa (gludopa) and its metabolite, L-dopa, have been studied in normal rats at three dose levels of gludopa: 2 mg kg-1, 5 mg kg-1 and 7.5 mg kg-1. The extent of metabolism in normal rats, and the pharmacokinetics in anephric rats and rats with glycerol-induced acute renal failure (ARF) were also studied at a gludopa dose of 2 mg kg-1. 2. Gludopa was extensively metabolised to L-dopa with only about 10% of an injected dose being excreted unchanged. Normal rats had a rapid gludopa clearance of 50.9 +/- 9.6 ml min-1 kg-1 and elimination rate constant of 2.99 +/- 0.27 h-1. The mean residence time and half-life were 20.9 +/- 1.4 and 14.4 +/- 1.0 min, respectively. The apparent volume of distribution at steady state was 1.05 +/- 0.18 l kg-1. 3. No statistically significant differences were found in the main pharmacokinetic parameters between ARF and controls for either gludopa or its metabolite L-dopa. 4. In anephric rats and controls the kidneys were found to contribute about 68.5% and 67.2% to the elimination of gludopa and the metabolite L-dopa, respectively. 5. These results confirm that gludopa is an efficient pro-drug for L-dopa, and that the kidneys are the major site of gludopa metabolism. It seems likely that the renal specificity of gludopa persists in ARF.  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