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   65052篇
  免费   4905篇
  国内免费   138篇
耳鼻咽喉   532篇
儿科学   2392篇
妇产科学   2246篇
基础医学   8046篇
口腔科学   856篇
临床医学   10603篇
内科学   11904篇
皮肤病学   1002篇
神经病学   6039篇
特种医学   1420篇
外国民族医学   35篇
外科学   6383篇
综合类   912篇
一般理论   90篇
预防医学   8634篇
眼科学   865篇
药学   3716篇
  1篇
中国医学   106篇
肿瘤学   4313篇
  2023年   348篇
  2022年   465篇
  2021年   1250篇
  2020年   851篇
  2019年   1333篇
  2018年   1576篇
  2017年   1109篇
  2016年   1242篇
  2015年   1307篇
  2014年   1855篇
  2013年   2997篇
  2012年   4216篇
  2011年   4455篇
  2010年   2387篇
  2009年   2256篇
  2008年   3942篇
  2007年   4370篇
  2006年   4241篇
  2005年   4117篇
  2004年   3917篇
  2003年   3749篇
  2002年   3524篇
  2001年   793篇
  2000年   673篇
  1999年   765篇
  1998年   802篇
  1997年   653篇
  1996年   567篇
  1995年   485篇
  1994年   494篇
  1993年   457篇
  1992年   545篇
  1991年   520篇
  1990年   483篇
  1989年   406篇
  1988年   440篇
  1987年   438篇
  1986年   413篇
  1985年   396篇
  1984年   392篇
  1983年   394篇
  1982年   396篇
  1981年   378篇
  1980年   303篇
  1979年   333篇
  1978年   249篇
  1977年   236篇
  1976年   233篇
  1975年   212篇
  1974年   213篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
ABSTRACT

Close observation of the interactions between a traumatised mother and her infant son provides information on the modes of transmission of psychic trauma in the mother–infant dyad. Following the presentation of a current literature review on the theme, the subject of “radioactive residue” and counter-transference in the transmission of psychic trauma from mother to infant will be illustrated through a clinical case study that focuses on a Haitian mother and her two-year-old infant son who has been referred to a “transitional care nursery” in urban Paris. The encounter with this mother–infant dyad is analysed through observing the quality of the interactions that take place between the mother and infant in order to determine how a particularly traumatic narrative impacts the mother–infant relationship, in addition to relations with the clinician. Mother and infant respond to one another through the emission and reception of “radioactive residues” as hypothesized by Gampel. This clinical case study shows that there is a need to consider transcultural factors and collective experience and history when analysing traumatic events. Additionally, the case study shows that counter-transference can be an effective clinical tool for gaining access to an infant's experience as the recipient of a traumatic narrative.  相似文献   
4.
Prevalence of osteoporosis is more than 50% in older adults, yet current clinical methods for diagnosis that rely on areal bone mineral density (aBMD) fail to detect most individuals who have a fragility fracture. Bone fragility can manifest in different forms, and a “one-size-fits-all” approach to diagnosis and management of osteoporosis may not be suitable. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides additive information by capturing information about volumetric density and microarchitecture, but interpretation is challenging because of the complex interactions between the numerous properties measured. In this study, we propose that there are common combinations of bone properties, referred to as phenotypes, that are predisposed to different levels of fracture risk. Using HR-pQCT data from a multinational cohort (n = 5873, 71% female) between 40 and 96 years of age, we employed fuzzy c-means clustering, an unsupervised machine-learning method, to identify phenotypes of bone microarchitecture. Three clusters were identified, and using partial correlation analysis of HR-pQCT parameters, we characterized the clusters as low density, low volume, and healthy bone phenotypes. Most males were associated with the healthy bone phenotype, whereas females were more often associated with the low volume or low density bone phenotypes. Each phenotype had a significantly different cumulative hazard of major osteoporotic fracture (MOF) and of any incident osteoporotic fracture (p < 0.05). After adjustment for covariates (cohort, sex, and age), the low density followed by the low volume phenotype had the highest association with MOF (hazard ratio = 2.96 and 2.35, respectively), and significant associations were maintained when additionally adjusted for femoral neck aBMD (hazard ratio = 1.69 and 1.90, respectively). Further, within each phenotype, different imaging biomarkers of fracture were identified. These findings suggest that osteoporotic fracture risk is associated with bone phenotypes that capture key features of bone deterioration that are not distinguishable by aBMD. © 2021 American Society for Bone and Mineral Research (ASBMR).  相似文献   
5.
6.
7.
8.
9.
10.

Introduction

Little is known about dementia incidence in diverse populations of oldest-old, the age group with highest dementia incidence.

Methods

Incident dementia diagnoses from 1/1/2010 to 9/30/2015 were abstracted from medical records for 2350 members of an integrated health care system in California (n = 1702 whites, n = 375 blacks, n = 105 Latinos, n = 168 Asians) aged ≥90 in 2010. We estimated race/ethnicity-specific age-adjusted dementia incidence rates and implemented Cox proportional hazards models and Fine and Gray competing risk of death models adjusted for demographics and comorbidities in midlife and late-life.

Results

Dementia incidence rates (n = 771 cases) were lowest among Asians (89.9/1000 person-years), followed by whites (96.9/1000 person-years), Latinos (105.8/1000 person-years), and blacks (121.5/1000 person-years). Cox regression and competing risk models estimated 28% and 36% higher dementia risk for blacks versus whites adjusting for demographics and comorbidities.

Discussion

Patterns of racial/ethnic disparities in dementia seen in younger older adults continue after the age of 90 years, though smaller in magnitude.  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