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   3473篇
  免费   213篇
  国内免费   4篇
耳鼻咽喉   16篇
儿科学   86篇
妇产科学   124篇
基础医学   446篇
口腔科学   25篇
临床医学   407篇
内科学   567篇
皮肤病学   63篇
神经病学   375篇
特种医学   46篇
外科学   492篇
综合类   22篇
一般理论   2篇
预防医学   487篇
眼科学   44篇
药学   205篇
中国医学   1篇
肿瘤学   282篇
  2024年   2篇
  2023年   49篇
  2022年   78篇
  2021年   146篇
  2020年   97篇
  2019年   142篇
  2018年   145篇
  2017年   95篇
  2016年   124篇
  2015年   104篇
  2014年   161篇
  2013年   224篇
  2012年   322篇
  2011年   317篇
  2010年   149篇
  2009年   114篇
  2008年   212篇
  2007年   223篇
  2006年   175篇
  2005年   201篇
  2004年   158篇
  2003年   134篇
  2002年   121篇
  2001年   19篇
  2000年   5篇
  1999年   13篇
  1998年   19篇
  1997年   11篇
  1996年   4篇
  1995年   15篇
  1994年   8篇
  1993年   13篇
  1992年   7篇
  1991年   14篇
  1990年   3篇
  1989年   5篇
  1988年   2篇
  1987年   4篇
  1986年   4篇
  1985年   4篇
  1984年   3篇
  1983年   9篇
  1982年   7篇
  1981年   4篇
  1980年   3篇
  1978年   6篇
  1975年   4篇
  1943年   1篇
  1942年   1篇
  1939年   1篇
排序方式: 共有3690条查询结果,搜索用时 9 毫秒
101.
102.
103.
In the current investigation, the neurophysiological organization of the neocortex was examined in adult animals that were bilaterally enucleated very early in life, before the retino-geniculo-cortical pathway was established. Our results indicate that some aspects of development of cortical fields are not mediated by specific sensory inputs. However, the current study also demonstrates that peripheral innervation plays a large role in the organization of the neocortex, as cortical territories normally involved in visual processing are completely captured by the auditory and somatosensory system. Thus, a large degree of phenotypic variability in cortical organization can be accomplished solely by removing or modifying sensory inputs.  相似文献   
104.
PurposeHaving an emergency plan may reduce negative effects of disaster on the health of postpartum women and their infants. However, little is known about the prevalence of emergency plans among postpartum women. In 2009, Arkansas added a question to the Pregnancy Risk Assessment Monitoring System surveillance system about whether women who gave birth that year had an emergency plan. In this study, we first describe the sociodemographic characteristics, disaster experience, and region of residence of postpartum women in Arkansas who indicated that they had an emergency plan for their families in 2009, and second, examine associations between sociodemographic characteristics and disaster experience and the presence of an emergency plan.MethodsMultivariable logistic regression (n = 1,173) was conducted to examine associations between maternal race/ethnicity, sociodemographic characteristics, region of residence, disaster experience, and having a disaster plan. We adjusted for maternal education, federal poverty level, and family size in our final model.FindingsForty-eight percent (n = 559) of women reported having an emergency plan. Hispanic women were less likely to report having a plan compared with non-Hispanic White women (n = 102 [10%]; adjusted prevalence ratio [aPR], 0.6; 95% confidence interval [CI], 0.4–0.9). Families with five or more members were more likely to have a plan compared with smaller families (n = 123 [11%]; aPR, 1.3; 95% CI, 1.1–1.6).ConclusionsPolicymakers and public health practitioners can use these results to promote emergency planning among postpartum women in Arkansas, with special outreach to postpartum women who are Hispanic or have smaller families.  相似文献   
105.
106.
The accumulation of hyperphosphorylated tau is a common feature of several dementias. Tau is one of the brain microtubule-associated proteins. Here we discuss tau’s functions in microtubule assembly and stabilization and with regard to its interactions with other proteins. We describe and analyze important post-translational modifications: hyperphosphorylation, ubiquitination, glycation, glycosylation, nitration, polyamination, proteolysis, acetylation, and methylation. We discuss how these post-translational modifications can alter tau’s biological function. We analyze the role of mitochondrial health in neurodegeneration. We propose that microtubules could be a therapeutic target and review different approaches. Finally, we consider whether tau accumulation or its conformational change is related to tau-induced neurodegeneration, and propose a mechanism of neurodegeneration.  相似文献   
107.
108.
109.
110.
Coronavirus disease 2019 (COVID-19) continues to impact older adults disproportionately with respect to serious consequences ranging from severe illness and hospitalization to increased mortality risk. Concurrently, concerns about potential shortages of healthcare professionals and health supplies to address these issues have focused attention on how these resources are ultimately allocated and used. Some strategies, for example, misguidedly use age as an arbitrary criterion that disfavors older adults in resource allocation decisions. This is a companion article to the American Geriatrics Society (AGS) position statement, “Resource Allocation Strategies and Age-Related Considerations in the COVID-19 Era and Beyond.” It is intended to inform stakeholders including hospitals, health systems, and policymakers about ethical considerations that should be considered when developing strategies for allocation of scarce resources during an emergency involving older adults. This review presents the legal and ethical background for the position statement and discusses these issues that informed the development of the AGS positions: (1) age as a determining factor, (2) age as a tiebreaker, (3) criteria with a differential impact on older adults, (4) individual choices and advance directives, (5) racial/ethnic disparities and resource allocation, and (6) scoring systems and their impact on older adults. It also considers the role of advance directives as expressions of individual preferences in pandemics. J Am Geriatr Soc 68:1143–1149, 2020.  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