首页 | 官方网站   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   39472篇
  免费   3320篇
  国内免费   211篇
医药卫生   43003篇
  2023年   276篇
  2022年   224篇
  2021年   1035篇
  2020年   639篇
  2019年   913篇
  2018年   1110篇
  2017年   748篇
  2016年   895篇
  2015年   1033篇
  2014年   1418篇
  2013年   1705篇
  2012年   2742篇
  2011年   2790篇
  2010年   1562篇
  2009年   1431篇
  2008年   2390篇
  2007年   2370篇
  2006年   2211篇
  2005年   2186篇
  2004年   2062篇
  2003年   1881篇
  2002年   1633篇
  2001年   1169篇
  2000年   1054篇
  1999年   938篇
  1998年   394篇
  1997年   300篇
  1996年   252篇
  1995年   249篇
  1994年   217篇
  1993年   189篇
  1992年   524篇
  1991年   490篇
  1990年   443篇
  1989年   402篇
  1988年   364篇
  1987年   336篇
  1986年   335篇
  1985年   325篇
  1984年   228篇
  1983年   208篇
  1982年   142篇
  1981年   103篇
  1980年   115篇
  1979年   162篇
  1978年   96篇
  1977年   104篇
  1976年   70篇
  1974年   86篇
  1973年   76篇
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
1.
2.
3.
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   
4.
Abstract

Objective

Ras wild-type metastatic colorectal cancers (mCRC) may be treated with anti-vascular endothelial growth factor (VEGF) or anti-epidermal growth factor receptor (EGFR) agents. We aim to estimate patients’ preferences for mCRC treatment and relative importance of cost, efficacy improvement, avoidance of side effects and therapy convenience, and relative uptake between profiles that resemble Bevacizumab (anti-VEGF) and Cetuximab (anti-EGFR), two commonly prescribed mCRC targeted therapies.  相似文献   
5.
6.
7.
8.
9.
10.
Background: Physicians have long had patients whom they have labeled “difficult”, but little is known about how medical students perceive difficult encounters with patients.

Methods: In this study, we analyzed 134 third year medical students’ reflective essays written over an 18-month period about difficult student–patient encounters. We used a qualitative computerized software program, Atlas.ti to analyze students’ observations and reflections.

Results: Main findings include that students described patients who were angry and upset; noncompliant with treatment plans; discussed “nonmedical” problems; fearful, worried, withdrawn, or “disinterested” in their health. Students often described themselves as anxious, uncertain, confused, and frustrated. Nevertheless, they saw themselves behaving in empathic and patient-centered ways while also taking refuge in “standard” behaviors not necessarily appropriate to the circumstances. Students rarely mentioned receiving guidance from attendings regarding how to manage these challenging interactions.

Conclusions: These third-year medical students recognized the importance of behaving empathically in difficult situations and often did so. However, they often felt overwhelmed and frustrated, resorting to more reductive behaviors that did not match the needs of the patient. Students need more guidance from attending physicians in order to approach difficult interactions with specific problem-solving skills while maintaining an empathic, patient-centered context.  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-23

京公网安备 11010802026262号