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   427篇
  免费   23篇
  国内免费   12篇
耳鼻咽喉   1篇
儿科学   13篇
妇产科学   5篇
基础医学   43篇
口腔科学   24篇
临床医学   55篇
内科学   120篇
皮肤病学   3篇
神经病学   6篇
特种医学   74篇
外科学   23篇
综合类   18篇
预防医学   38篇
眼科学   1篇
药学   20篇
中国医学   1篇
肿瘤学   17篇
  2023年   5篇
  2022年   7篇
  2021年   8篇
  2020年   6篇
  2019年   5篇
  2018年   9篇
  2017年   4篇
  2016年   12篇
  2015年   7篇
  2014年   8篇
  2013年   15篇
  2012年   6篇
  2011年   7篇
  2010年   20篇
  2009年   25篇
  2008年   6篇
  2007年   21篇
  2006年   5篇
  2005年   3篇
  2004年   7篇
  2003年   4篇
  2002年   3篇
  2001年   5篇
  2000年   3篇
  1999年   5篇
  1998年   30篇
  1997年   30篇
  1996年   30篇
  1995年   27篇
  1994年   17篇
  1993年   19篇
  1992年   7篇
  1991年   3篇
  1990年   11篇
  1989年   13篇
  1988年   14篇
  1987年   19篇
  1986年   6篇
  1985年   4篇
  1984年   5篇
  1983年   1篇
  1982年   2篇
  1981年   2篇
  1980年   3篇
  1979年   1篇
  1978年   1篇
  1977年   5篇
  1976年   3篇
  1975年   3篇
排序方式: 共有462条查询结果,搜索用时 15 毫秒
81.
The refusal rate for organ donation in the UK is 42%, among the highest in Europe. We extracted data on every family approach for donation in UK ICUs or Emergency Departments between 1st April 2012 and 30th September 2013, and performed multiple logistic regression to identify modifiable factors associated with consent. Complete data were available for 4703 of 4899 approaches during the study period. Consent for donation after brain death was 68.9%, and for donation after circulatory death 56.5% (p < 0.0001). Patient ethnicity, knowledge of a patient's wishes and involvement of a specialist nurse in organ donation in the approach were strongly associated with consent (p < 0.0001). The impact of the specialist nurse was stronger for donation after circulatory death than for donation after brain death, even after accounting for the impact of prior knowledge of patients' wishes. Involvement of the specialist nurse in the approach, encouraging family discussions about donation wishes and promotion of the organ donor register are key strategies to increase UK consent rates, and are supported by this study.  相似文献   
82.
83.
84.
85.
86.
87.
88.
报道了氯仿重结晶的棉酚的化学性质,样品在不同温度下干燥恒重后,经熔点、薄层层析、紫外光谱、红外光谱、X-射线衍射、热重量分析、元素(C,H,Cl)分析及棉酚合量测定等一系列的分析,确证了在60℃以下棉酚与氯仿成溶剂化物(solvate)。随着干燥温度的升高或在室温长时间的贮存,此现象逐渐消失,100℃真空干燥恒重后成为纯棉酚。  相似文献   
89.
Background Perceived age is important to women and is a primary driver for topical product use and facial cosmetic surgery. Changes in facial features and biophysical skin parameters with chronological age and their associations with perceived age have not been described in Asian populations. Objective To investigate the relationship between biophysical properties of the skin, visual features of skin ageing and perceived facial age in Chinese women. Methods Facial photographs were collected of 250 Chinese women, aged 25–70 years in Shanghai, China. The perceived facial age was determined and related to the chronological age for each participant and to a range of visual assessments of skin appearance and objective biophysical measurements of the skin. The profile of changes in these parameters with age was investigated together with the differences in those parameters for women judged to look younger than their chronological age and those judged to look older than their chronological age. Results Large discrepancies in perceived age (up to 29 years) were found in women of the same chronological age. Each objective skin measure and visual assessment parameter had a stronger correlation with perceived age than with chronological age. The strongest relationships to perceived age were for wrinkles and hyperpigmentation. Skin colour, hydration and trans‐epidermal water loss (TEWL) had weaker associations with perceived age. Women judged to look older than their chronological age had significantly higher scores than those judged to look younger for coarse wrinkles and hyperpigmentation across all age groups. The appearance differences between these groups were evident in composite facial images of the same average chronological age. Conclusions We have identified the skin attributes which differ with perceived age in Chinese women. Perceived age is a better measure of the biological age of facial skin than is chronological age in this population.  相似文献   
90.
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