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   981953篇
  免费   70850篇
  国内免费   1440篇
耳鼻咽喉   13440篇
儿科学   26509篇
妇产科学   24663篇
基础医学   139230篇
口腔科学   28735篇
临床医学   88677篇
内科学   191921篇
皮肤病学   19921篇
神经病学   77049篇
特种医学   37711篇
外国民族医学   79篇
外科学   156271篇
综合类   18599篇
现状与发展   1篇
一般理论   340篇
预防医学   69087篇
眼科学   21986篇
药学   75935篇
  3篇
中国医学   2219篇
肿瘤学   61867篇
  2018年   10049篇
  2017年   7930篇
  2016年   8707篇
  2015年   9983篇
  2014年   13525篇
  2013年   20023篇
  2012年   27689篇
  2011年   28945篇
  2010年   17012篇
  2009年   16227篇
  2008年   28153篇
  2007年   29462篇
  2006年   30133篇
  2005年   29193篇
  2004年   28141篇
  2003年   26990篇
  2002年   26262篇
  2001年   55168篇
  2000年   56865篇
  1999年   47394篇
  1998年   11366篇
  1997年   10034篇
  1996年   10037篇
  1995年   9376篇
  1994年   8685篇
  1993年   7915篇
  1992年   35718篇
  1991年   34107篇
  1990年   32908篇
  1989年   32060篇
  1988年   29164篇
  1987年   28408篇
  1986年   26445篇
  1985年   25300篇
  1984年   18013篇
  1983年   15299篇
  1982年   8006篇
  1981年   6968篇
  1979年   15873篇
  1978年   10698篇
  1977年   9100篇
  1976年   7923篇
  1975年   8670篇
  1974年   10527篇
  1973年   9894篇
  1972年   9385篇
  1971年   8875篇
  1970年   8439篇
  1969年   7931篇
  1968年   7206篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
23.
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   
24.
Background: Poor anger regulation is considered a risk factor of aggression in individuals with mild or borderline intellectual disabilities. Psychomotor therapy (PMT) targets anger regulation through body- and movement-oriented interventions. This study aims to inform practitioners on efficacy and research-base of PMT in this population.

Method: This systematic review evaluated nine studies which met inclusion criteria in terms of participants, intervention procedures, outcomes and certainty of evidence.

Results: Seven studies revealed a substantial reduction of aggressive behaviour or anger. Certainty of evidence was rated inconclusive in most cases due to absence of experimental control.

Conclusions: We can conclude that body-oriented PMT, involving progressive relaxation and meditation procedure “Soles of the Feet”, is a promising approach. However, the paucity of studies and methodological limitations preclude classifying it as an evidence-based practice. This suggests stronger methodological research and research aimed at PMT’s mechanisms of action (e.g., improved interoceptive awareness) is warranted.  相似文献   

25.
Purpose: To review the systemic and ocular manifestations of specific emergent viral infectious diseases relevant to the ophthalmologist with particular emphasis on anterior uveitis

Methods: Review of literature.

Results: Arboviral diseases are among the most important emergent and resurgent human infections, occurring mostly in tropical and subtropical zones, but appearing in virtually all regions of the world as a result of climate change, travel, and globalization. Arboviral infections are transmitted to humans by the bite of hematophagous arthropods, mainly mosquitoes. Systemic disease may range from asymptomatic to life-threatening. A wide variety of ocular manifestations, including uveitis, has been reported in association with these emerging viral diseases. Numerous viruses other than arboviruses also have been recently recognized as a potential cause of uveitis.

Conclusions: Proper clinical diagnosis of any emerging infectious disease is based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. The diagnosis is usually confirmed by detection of virus-specific DNA or antivirus antibodies in serum.  相似文献   
26.
27.
28.
ContextIt is especially important that patients are well informed when making high-stakes, preference-sensitive decisions like those on the Physician Orders for Life-Sustaining Treatment (POLST) form. However, there is currently no way to easily evaluate whether patients understand key concepts when making these important decisions.ObjectivesTo develop a POLST knowledge survey.MethodsExpert (n = 62) ratings of key POLST facts were used to select items for a POLST knowledge survey. The survey was administered to nursing facility residents (n = 97) and surrogate decision-makers (n = 112). A subset (n = 135) were re-administered the survey after a standardized advance care planning discussion to assess the scale's responsiveness to change.ResultsThe 19-item survey demonstrated adequate reliability (α = 0.72.). Residents' scores (x = 11.4, standard deviation 3.3) were significantly lower than surrogate scores (x = 14.7, standard deviation 2.5) (P < 0.001). Scores for both groups increased significantly after administration of a standardized advance care planning discussion (P < 0.001). Although being a surrogate, age, race, education, cognitive functioning, and health literacy were significantly associated with higher POLST Knowledge Survey scores in univariate analyses, only being a surrogate (P < 0.001) and being white (P = 0.028) remained significantly associated with higher scores in multivariate analyses.ConclusionThe 19-item POLST Knowledge Survey demonstrated adequate reliability and responsiveness to change. Findings suggest the survey could be used to identify knowledge deficits and provide targeted education to ensure adequate understanding of key clinical decisions when completing POLST.  相似文献   
29.
30.
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