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   1339467篇
  免费   100712篇
  国内免费   4283篇
耳鼻咽喉   16835篇
儿科学   43788篇
妇产科学   36450篇
基础医学   198326篇
口腔科学   36002篇
临床医学   129919篇
内科学   259049篇
皮肤病学   26451篇
神经病学   112078篇
特种医学   48374篇
外国民族医学   366篇
外科学   184750篇
综合类   28850篇
现状与发展   1篇
一般理论   462篇
预防医学   114605篇
眼科学   29146篇
药学   99357篇
  6篇
中国医学   3211篇
肿瘤学   76436篇
  2021年   11064篇
  2019年   11761篇
  2018年   16474篇
  2017年   12389篇
  2016年   13366篇
  2015年   15323篇
  2014年   21003篇
  2013年   32290篇
  2012年   44567篇
  2011年   47252篇
  2010年   27265篇
  2009年   25087篇
  2008年   42988篇
  2007年   45336篇
  2006年   45406篇
  2005年   43788篇
  2004年   41751篇
  2003年   39659篇
  2002年   38487篇
  2001年   60886篇
  2000年   62552篇
  1999年   52312篇
  1998年   14613篇
  1997年   13298篇
  1996年   13136篇
  1995年   12480篇
  1994年   11636篇
  1993年   10942篇
  1992年   41595篇
  1991年   40792篇
  1990年   39477篇
  1989年   37365篇
  1988年   34601篇
  1987年   33717篇
  1986年   32168篇
  1985年   30647篇
  1984年   23068篇
  1983年   19602篇
  1982年   11771篇
  1979年   20823篇
  1978年   14824篇
  1977年   12073篇
  1976年   11884篇
  1975年   12120篇
  1974年   14810篇
  1973年   14487篇
  1972年   13363篇
  1971年   12425篇
  1970年   11495篇
  1969年   10415篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
42.
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   
43.
44.
45.
46.
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   
47.
48.
49.
Nevo  N.  Goldstein  A. L.  Staierman  M.  Eran  N.  Carmeli  I.  Rayman  S.  mnouskin  Y. 《Hernia》2022,26(6):1491-1499
Hernia - The minimally invasive surgical repair of combined inguinal and ventral hernias often requires shifting from one approach or plane to another. The traditional enhanced-view totally...  相似文献   
50.
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