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   1726篇
  免费   162篇
  国内免费   6篇
耳鼻咽喉   29篇
儿科学   61篇
妇产科学   61篇
基础医学   201篇
口腔科学   7篇
临床医学   194篇
内科学   318篇
皮肤病学   37篇
神经病学   215篇
特种医学   27篇
外科学   219篇
综合类   13篇
一般理论   5篇
预防医学   269篇
眼科学   8篇
药学   115篇
  1篇
肿瘤学   114篇
  2024年   2篇
  2023年   63篇
  2022年   58篇
  2021年   186篇
  2020年   97篇
  2019年   140篇
  2018年   166篇
  2017年   110篇
  2016年   82篇
  2015年   83篇
  2014年   104篇
  2013年   120篇
  2012年   165篇
  2011年   139篇
  2010年   50篇
  2009年   52篇
  2008年   59篇
  2007年   63篇
  2006年   44篇
  2005年   29篇
  2004年   31篇
  2003年   22篇
  2002年   13篇
  2001年   2篇
  2000年   1篇
  1999年   4篇
  1998年   1篇
  1992年   1篇
  1990年   1篇
  1983年   1篇
  1982年   3篇
  1981年   2篇
排序方式: 共有1894条查询结果,搜索用时 15 毫秒
1.
2.
DNA methylation at CpG dinucleotides is an important epigenetic regulator common to virtually all mammalian cell types, but recent evidence indicates that during early postnatal development neuronal genomes also accumulate uniquely high levels of two alternative forms of methylation, non-CpG methylation and hydroxymethylation. Here we discuss the distinct landscape of DNA methylation in neurons, how it is established, and how it might affect the binding and function of protein readers of DNA methylation. We review studies of one critical reader of DNA methylation in the brain, the Rett syndrome protein methyl CpG-binding protein 2 (MeCP2), and discuss how differential binding affinity of MeCP2 for non-CpG and hydroxymethylation may affect the function of this methyl-binding protein in the nervous system.  相似文献   
3.
4.
5.
We evaluated nucleic acid amplification testing (NAAT) for Zika virus on whole-blood specimens compared with NAAT on serum and urine specimens among asymptomatic pregnant women during the 2015–2016 Puerto Rico Zika outbreak. Using NAAT, more infections were detected in serum and urine than in whole blood specimens.  相似文献   
6.
ObjectivesThe purpose of our study was to identify factors that predict 1-year incident hip and major osteoporotic non-hip fractures (ie, wrist, spine, pelvis, humerus) for home care recipients while accounting for the competing risk of death.DesignWe conducted a retrospective cohort study with linked population data.Setting and ParticipantsAll home care recipients in Ontario, Canada, receiving services for more than 6 months with an admission assessment between April 1, 2011, and March 31, 2015, were included.MethodsClinical data from the Resident Assessment Instrument Home Care were linked to fracture data from the Discharge Abstract Database and the National Acute Care Reporting System. Competing risk proportional hazard regressions using the Fine and Grey method were performed to model the association between potential risk factors and fracture.ResultsPrevious fall, previous fracture, cognitive impairment, unsteady gait, alcohol use, tobacco use, and Parkinson disease were consistently associated with all fracture types. Cognitive impairment (hazard ratio 2.09; 95% confidence interval 1.86–2.36) and wandering [1.66 (1.06–1.27)] were most predictive of hip fractures and being female [1.86 (1.76–1.98)] and experiencing a previous fracture [1.86 (1.76–1.98)] were most predictive of non-hip fractures. Risk factors unique to non-hip fractures as compared with hip fractures were locomotion ability outdoors and psychotropic medication use.Conclusions and ImplicationsOur results indicate that, in addition to typical fracture risk factors, home care recipients have unique characteristics that increase their risk. Fracture risk assessment tools and subsequent prevention strategies should be modified to accurately identify home care recipients at risk for imminent 1-year fracture.  相似文献   
7.
8.
9.
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