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   1126143篇
  免费   76795篇
  国内免费   1627篇
耳鼻咽喉   15577篇
儿科学   36389篇
妇产科学   29999篇
基础医学   161298篇
口腔科学   30347篇
临床医学   99980篇
内科学   215650篇
皮肤病学   25559篇
神经病学   87310篇
特种医学   44107篇
外国民族医学   201篇
外科学   167432篇
综合类   22002篇
现状与发展   2篇
一般理论   306篇
预防医学   79464篇
眼科学   25399篇
药学   90237篇
  7篇
中国医学   2903篇
肿瘤学   70396篇
  2021年   9875篇
  2019年   9462篇
  2018年   13171篇
  2017年   10406篇
  2016年   11738篇
  2015年   13061篇
  2014年   17589篇
  2013年   25176篇
  2012年   34895篇
  2011年   36695篇
  2010年   21321篇
  2009年   19836篇
  2008年   33321篇
  2007年   35416篇
  2006年   35747篇
  2005年   33827篇
  2004年   32321篇
  2003年   30892篇
  2002年   29650篇
  2001年   60343篇
  2000年   61749篇
  1999年   51249篇
  1998年   12801篇
  1997年   11298篇
  1996年   11219篇
  1995年   10517篇
  1994年   9535篇
  1993年   9003篇
  1992年   37913篇
  1991年   36397篇
  1990年   35854篇
  1989年   34410篇
  1988年   30979篇
  1987年   30101篇
  1986年   28313篇
  1985年   26565篇
  1984年   19296篇
  1983年   16204篇
  1982年   8917篇
  1979年   17087篇
  1978年   11446篇
  1977年   10272篇
  1976年   8862篇
  1975年   10094篇
  1974年   11693篇
  1973年   11305篇
  1972年   10782篇
  1971年   10123篇
  1970年   9268篇
  1969年   8957篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
25.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
26.
27.
28.
Abstract

Supporting patients in making informed healthcare decisions is a cornerstone of ethical medical practice. Surgeons frequently draw for and show images to patients when consenting them for operations but the value of this practice in informed decision-making is unclear. An audit was conducted in a General Surgery Department. 244 patients completed questionnaires on the value of visual materials when giving consent for surgery. The complexity of the operations was classified into “simple”, “moderate” or “complex”. 100% of patients felt they had given informed consent to surgery. 62% of patients received at least one form of visual material during the consenting process. All patients who received a drawing, and 99% of those provided with other images, valued these resources. Visual materials were considered more useful to patients when giving consent for moderate or complex operations than simple ones. Approximately one third of patients who did not receive visual materials would have appreciated these when making an informed decision. This research highlights the value of surgeons drawing for, and providing other visual resources to, their patients as part of the consent process. There is a role for further research and training materials in drawing skills for surgeons.  相似文献   
29.
30.
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   
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