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   4195篇
  免费   250篇
  国内免费   23篇
耳鼻咽喉   37篇
儿科学   138篇
妇产科学   69篇
基础医学   555篇
口腔科学   110篇
临床医学   332篇
内科学   1047篇
皮肤病学   166篇
神经病学   374篇
特种医学   83篇
外科学   458篇
综合类   14篇
预防医学   391篇
眼科学   56篇
药学   323篇
中国医学   17篇
肿瘤学   298篇
  2023年   37篇
  2022年   77篇
  2021年   161篇
  2020年   72篇
  2019年   144篇
  2018年   154篇
  2017年   104篇
  2016年   99篇
  2015年   122篇
  2014年   140篇
  2013年   200篇
  2012年   281篇
  2011年   298篇
  2010年   172篇
  2009年   128篇
  2008年   234篇
  2007年   230篇
  2006年   219篇
  2005年   237篇
  2004年   221篇
  2003年   200篇
  2002年   200篇
  2001年   82篇
  2000年   91篇
  1999年   87篇
  1998年   39篇
  1997年   23篇
  1996年   25篇
  1995年   16篇
  1994年   12篇
  1993年   16篇
  1992年   25篇
  1991年   35篇
  1990年   34篇
  1989年   27篇
  1988年   21篇
  1987年   18篇
  1986年   17篇
  1985年   26篇
  1984年   11篇
  1983年   12篇
  1982年   7篇
  1981年   7篇
  1980年   7篇
  1979年   16篇
  1977年   8篇
  1975年   8篇
  1973年   12篇
  1972年   11篇
  1971年   9篇
排序方式: 共有4468条查询结果,搜索用时 15 毫秒
61.
62.
Diet is considered the cornerstone for the prevention of age-related diseases, and a low-fat diet has been considered for decades as the most suitable alternative to achieve this goal. However, mounting evidence supports the efficacy of other alternatives, such as the Mediterranean diet. Nevertheless, it is well known that people present a dramatic range of responses to similar environmental challenges, and it has been shown that some of this variability is rooted in the genome. In fact, this knowledge is driving the field of nutrigenetics. The finding of interactions between diet and genetic variants has led to intense research and debate about the effectiveness of personalized nutrition as a more suitable tool for the prevention of chronic diseases than the traditional 1-size-fits-all recommendations. Here, we provide some of our own examples that illustrate the progression of nutrigenetics through the years, from the initial studies within the Framingham Heart Study, to the most recent use of large consortia, such as the Cohorts for Heart and Aging Research in Genomic Epidemiology, and ending up with large dietary intervention studies, such as the PREDIMED (Prevención con Dieta Mediterránea) study. These recent approaches are providing more robust and clinically relevant gene–diet interactions. Therefore, although the current evidence level of applying genomic information to tailoring is at its early stages, the prospect of widespread incorporation of nutrigenetics to the clinical practice is encouraging.  相似文献   
63.
64.

Background

Chile Crece Contigo (ChCC) is defined as a comprehensive, intersectoral, and multicomponent policy that aims to help all children reach their full potential for development, regardless of their socio‐economic status.

Methods

This case study was developed on the basis of grey literature review and key informants' interviews.

Results

ChCC behaves as a complex adaptive system that combines universal and targeted benefits for the more vulnerable starting since gestation and until the children are 4 years old. Three key ministries are involved in ChCC management: health, education, and social development. Studies show adequate programme implementation and positive effects of ChCC on child development. In addition, it was found that the more families use ChCC benefits and the longer the subsystem has been operating in the commune, the greater the positive effects.

Conclusions

Strong political support based on principles of equity and child rights combined with strong evidence and funding commitment from government has been central to emergence, scaling up, and sustainability of ChCC. Further sustainability of ChCC will rely on firmly establishing a well‐trained and compensated cadre of early child development professionals and paraprofessionals as well as an improved management and evaluation decentralized system.  相似文献   
65.
66.
67.
Even‐number, medium‐chain dicarboxylic acids (DAs), naturally occurring in higher plants, are a promising alternative energy substrate. Unlike the homologous fatty acids, DAs are soluble in water as salts. They are β‐oxidized, providing acetyl‐CoA and succinyl‐CoA, the latter being an intermediate of the tricarboxylic acid cycle. Sebacic acid and dodecanedioic acid, DAs with 10 and 12 carbon atoms respectively, provide 6.6 and 7.2 kcal g−1 each; therefore, their energy density is intermediate between glucose and fatty acids. Dicarboxylic acids have been proved to be safe in both experimental animals and humans, and their use has recently been proposed in diabetes. Studies in animals and humans with type 2 diabetes showed that oral administration of sebacic acid improved glycaemic control, probably by enhancing insulin sensitivity, and reduced hepatic gluconeogenesis and glucose output. Moreover, dodecanedioic acid intake reduced muscle fatigue during exercise in subjects with type 2 diabetes, suggesting an improvement of energy utilization and ‘metabolic flexibility’. In this article, we review the natural sources of DAs, their fate in animals and humans and their effect in improving glucose metabolism in type 2 diabetes.  相似文献   
68.
The antimicrobial and antiparasite activity of phospholipase A2 (PLA2) from snakes and bees has been extensively explored. We studied the antiplasmodial effect of the whole venom of the snake Bothrops asper and of two fractions purified by ion-exchange chromatography: one containing catalytically-active phospholipases A2 (PLA2) (fraction V) and another containing a PLA2 homologue devoid of enzymatic activity (fraction VI). The antiplasmodial effect was assessed on in vitro cultures of Plasmodium falciparum. The whole venom of B. asper, as well as its fractions V and VI, were active against the parasite at 0.13 ± 0.01 µg/mL, 1.42 ± 0.56 µg/mL and 22.89 ± 1.22 µg/mL, respectively. Differences in the cytotoxic activity on peripheral blood mononuclear cells between the whole venom and fractions V and VI were observed, fraction V showing higher toxicity than total venom and fraction VI. Regarding toxicity in mice, the whole venom showed the highest lethal effect in comparison to fractions V and VI. These results suggest that B. asper PLA2 and its homologue have antiplasmodial potential.  相似文献   
69.
70.
The chicken chorioallantoic membrane (CAM) is a simple, highly vascularized extraembryonic membrane, which performs multiple functions during embryonic development, including but not restricted to gas exchange. Over the last two decades, interest in the CAM as a robust experimental platform to study blood vessels has been shared by specialists working in bioengineering, development, morphology, biochemistry, transplant biology, cancer research and drug development. The tissue composition and accessibility of the CAM for experimental manipulation, makes it an attractive preclinical in vivo model for drug screening and/or for studies of vascular growth. In this article we provide a detailed review of the use of the CAM to study vascular biology and response of blood vessels to a variety of agonists. We also present distinct cultivation protocols discussing their advantages and limitations and provide a summarized update on the use of the CAM in vascular imaging, drug delivery, pharmacokinetics and toxicology.  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