全文获取类型
收费全文 | 873677篇 |
免费 | 71600篇 |
国内免费 | 1853篇 |
专业分类
耳鼻咽喉 | 12988篇 |
儿科学 | 24938篇 |
妇产科学 | 25376篇 |
基础医学 | 125520篇 |
口腔科学 | 26087篇 |
临床医学 | 76394篇 |
内科学 | 167367篇 |
皮肤病学 | 17106篇 |
神经病学 | 71323篇 |
特种医学 | 35482篇 |
外国民族医学 | 171篇 |
外科学 | 137751篇 |
综合类 | 24801篇 |
现状与发展 | 2篇 |
一般理论 | 273篇 |
预防医学 | 68001篇 |
眼科学 | 20788篇 |
药学 | 65271篇 |
16篇 | |
中国医学 | 1597篇 |
肿瘤学 | 45878篇 |
出版年
2018年 | 7497篇 |
2015年 | 7859篇 |
2014年 | 11311篇 |
2013年 | 17192篇 |
2012年 | 23170篇 |
2011年 | 24289篇 |
2010年 | 14131篇 |
2009年 | 13324篇 |
2008年 | 23048篇 |
2007年 | 25150篇 |
2006年 | 25028篇 |
2005年 | 24676篇 |
2004年 | 24280篇 |
2003年 | 23347篇 |
2002年 | 22466篇 |
2001年 | 35986篇 |
2000年 | 36614篇 |
1999年 | 31050篇 |
1998年 | 9353篇 |
1997年 | 8679篇 |
1996年 | 8593篇 |
1995年 | 8114篇 |
1994年 | 7832篇 |
1992年 | 26805篇 |
1991年 | 26226篇 |
1990年 | 25711篇 |
1989年 | 24818篇 |
1988年 | 23342篇 |
1987年 | 23016篇 |
1986年 | 21860篇 |
1985年 | 21264篇 |
1984年 | 16538篇 |
1983年 | 14149篇 |
1982年 | 9011篇 |
1981年 | 8343篇 |
1980年 | 7835篇 |
1979年 | 16869篇 |
1978年 | 12267篇 |
1977年 | 10312篇 |
1976年 | 9445篇 |
1975年 | 10235篇 |
1974年 | 12714篇 |
1973年 | 12230篇 |
1972年 | 11619篇 |
1971年 | 10744篇 |
1970年 | 10257篇 |
1969年 | 9965篇 |
1968年 | 8943篇 |
1967年 | 8267篇 |
1966年 | 7687篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
Journal of Digital Imaging - A lay-language glossary of radiology, built to help patients better understand the content of their radiology reports, has been analyzed for its coverage and... 相似文献
102.
W. Robert Bell Alan K. Meeker Anthony Rizzo Sumit Rajpara Ian M. Rosenthal Miguel Flores Bellver Silvia Aparicio Domingo Xiufeng Zhong John R. Barber Corinne E. Joshu M. Valeria Canto‐Soler Charles G. Eberhart Christopher M. Heaphy 《Brain pathology (Zurich, Switzerland)》2019,29(1):45-52
We have identified a discrete, focal telomere DNA expansion phenotype in the photoreceptor cell layer of normal, non‐neoplastic human retinas. This phenotype is similar to that observed in a subset of human cancers, including a large fraction of tumors of the central nervous system, which maintain their telomeres via the non‐telomerase‐mediated alternative lengthening of telomeres (ALT) mechanism. We observed that these large, ultra‐bright telomere DNA foci are restricted to the rod photoreceptors and are not observed in other cell types. Additionally, focus‐positive rod cells are dispersed homogeneously throughout the posterior retinal photoreceptor cell layer and appear to be human‐specific. We examined 108 normal human retinas obtained at autopsy from a wide range of ages. These large, ultra‐bright telomere DNA foci were not observed in infants before 6 months of age; however, the prevalence of focus‐positive rod cells dramatically increased throughout life. To investigate associations between this phenotype and retinal pathology, we assessed adult glaucoma (N = 29) and diabetic retinopathy (N = 38) cases. Focus‐positive rod cells were prominent in these diseases. When compared to the normal group, after adjusting for age, logistic regression modeling revealed significantly increased odds of falling in the high category of focus‐positive rod cells for glaucoma and diabetic retinopathy. In summary, we have identified a dramatic telomere alteration associated with aging and diseases affecting the retina. 相似文献
103.
104.
105.
Claudio Sartini Peter Tammes Alastair D. Hay Ian Preston Daniel Lasserson Peter H. Whincup S. Goya Wannamethee Richard W. Morris 《Annals of epidemiology》2018,28(1):1-7.e3
Purpose
Living in a cold home increases the risk of dying in winter, especially in older people. However, it is unclear which individual factors predict whether older people are living in cold homes.Methods
Thousand four hundred two men aged 74–95 years from a U.K. population–based study reported difficulties in keeping warm during winter, answering four simple “yes/no” questions. Associations between individual's characteristics and each of the four self-reported measures of cold homes were estimated using logistic regression models. Next, we investigated whether measures of cold homes predict mortality over the subsequent 2.1 years.Results
Manual social class, difficulties making ends meet, and not being married were each associated (P < .05) with each of the four measures of cold homes (adjusted odds ratios ranged from 1.61 to 4.68). Social isolation, poor respiratory health, and grip strength were also associated with reports of cold homes. Hundred twenty-six men died; those who reported the presence of at least three measures cold homes had increased mortality (adjusted hazard ratios 2.85 [95% confidence interval, 1.11–7.30, P = .029]).Conclusions
Older people who find it hard to keep warm in winter, and have an elevated mortality, could be identified using a self-report questionnaire. 相似文献106.
107.
Ha Diep H. Spencer A. John Thomson W. Murray Scott Jane A. Do Loc G. 《Maternal and child health journal》2018,22(4):617-625
Maternal and Child Health Journal - Objective The association between and commonality of risk factors for poor self-rated oral health (SROH) and general health (SRGH) among new mothers has not been... 相似文献
108.
Salene M. W. Jones Evette J. Ludman 《The journal of behavioral health services & research》2018,45(4):690-699
The focus on recovery, not just symptom reduction, in mental health care brings a need for psychometrically sound measures of recovery. This study examined the factor structure and sensitivity to change of a common measure of mental health recovery, the Recovery Assessment Scale (RAS). We conducted a secondary data analysis from a randomized clinical trial of self-management for depression (n = 302). We tested both bifactor and the previously found five-factor model. Sensitivity to change was examined three ways: (1) between the intervention and control group; (2) across time in the intervention group; and (3) in those whose depression remitted. The previous five-factor model was supported. One subscale, no domination by symptoms, was particularly sensitive to change and showed sensitivity to change whereas the subscale reliance on others did not show change in any of the comparisons. Results suggest that the subscales of the RAS should be examined separately in future studies of recovery. 相似文献
109.
110.
We introduce this supplemental issue of Prevention Science, which brings together a set of papers from leading investigators who have conducted trials testing whether intervention programs prevent adolescent depression. Using data from these trials, these papers explore a series of factors that might account for variation in intervention benefit, employing several novel methods for assessing effect heterogeneity. These studies follow two general paradigms: three papers report findings from single randomized preventive intervention trials, while the remaining papers develop and apply new methods for combining data from multiple studies to evaluate effect heterogeneity more broadly. Colleagues from NIMH and SAMHSA also provide commentaries on these studies. They conclude that synthesis of findings from multiple trials holds great promise for advancing the field, and progress will be accelerated if collaborative data sharing becomes the norm rather than the exception. 相似文献