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   1734篇
  免费   127篇
  国内免费   45篇
耳鼻咽喉   16篇
儿科学   124篇
妇产科学   122篇
基础医学   219篇
口腔科学   59篇
临床医学   189篇
内科学   335篇
皮肤病学   12篇
神经病学   88篇
特种医学   221篇
外科学   194篇
综合类   51篇
一般理论   2篇
预防医学   139篇
眼科学   11篇
药学   59篇
中国医学   1篇
肿瘤学   64篇
  2022年   8篇
  2021年   15篇
  2020年   12篇
  2019年   26篇
  2018年   32篇
  2017年   23篇
  2016年   25篇
  2015年   41篇
  2014年   55篇
  2013年   54篇
  2012年   71篇
  2011年   74篇
  2010年   49篇
  2009年   56篇
  2008年   59篇
  2007年   72篇
  2006年   52篇
  2005年   49篇
  2004年   51篇
  2003年   39篇
  2002年   39篇
  2001年   42篇
  2000年   35篇
  1999年   38篇
  1998年   54篇
  1997年   56篇
  1996年   51篇
  1995年   44篇
  1994年   56篇
  1993年   38篇
  1992年   32篇
  1991年   28篇
  1990年   32篇
  1989年   69篇
  1988年   60篇
  1987年   59篇
  1986年   44篇
  1985年   51篇
  1984年   38篇
  1983年   18篇
  1982年   16篇
  1981年   15篇
  1980年   12篇
  1979年   12篇
  1978年   13篇
  1976年   10篇
  1975年   8篇
  1973年   9篇
  1972年   8篇
  1969年   9篇
排序方式: 共有1906条查询结果,搜索用时 31 毫秒
1.

Objective

To examine the experience of interracial anxiety among health professionals and how it may affect the quality of their interactions with patients from racially marginalized populations. We explored the influence of prior interracial exposure—specifically through childhood neighborhoods, college student bodies, and friend groups—on interracial anxiety among medical students and residents. We also examined whether levels of interracial anxiety change from medical school through residency.

Data Source

Web-based longitudinal survey data from the Medical Student Cognitive Habits and Growth Evaluation Study.

Study Design

We used a retrospective longitudinal design with four observations for each trainee. The study population consisted of non-Black US medical trainees surveyed in their 1st and 4th years of medical school and 2nd and 3rd years of residency. Mixed effects longitudinal models were used to assess predictors of interracial anxiety and assess changes in interracial anxiety scores over time.

Principal Findings

In total, 3155 non-Black medical trainees were followed for 7 years. Seventy-eight percent grew up in predominantly White neighborhoods. Living in predominantly White neighborhoods and having less racially diverse friends were associated with higher levels of interracial anxiety among medical trainees. Trainees' interracial anxiety scores did not substantially change over time; interracial anxiety was highest in the 1st year of medical school, lowest in the 4th year, and increased slightly during residency.

Conclusions

Neighborhood and friend group composition had independent effects on interracial anxiety, indicating that premedical racial socialization may affect medical trainees' preparedness to interact effectively with diverse patient populations. Additionally, the lack of substantial change in interracial anxiety throughout medical training suggests the importance of providing curricular tools and structure (e.g., instituting interracial cooperative learning activities) to foster the development of healthy interracial relationships.  相似文献   
2.
3.
4.
SUMMARY A case congenital dislocation of both knees and dislocation of the left hip in an infant whose mother had a chronic amniotic fluid leakage after mid-trimester amniocentesis.  相似文献   
5.
6.
7.
本文建立了体液中右旋儿茶素的RP-HPLC测定方法。采用C_(18)键合相硅胶为填料的固相提取柱进行样品预处理,右旋儿茶素的提取回收率为79.8%.应用二极管阵列检测器对色谱峰纯度进行鉴定。该法精密度好,方法回收率近100%,日内、日间的变异系数为2.4~5.6%,血浓69.6~1160 ng/ml范围内呈线性关系,r=0.9993。家兔静注右旋儿茶素18mg/kg,其药代动力学过程符合二室模型,分布相半衰期为0.129 h,消除相半衰期为1.19h。  相似文献   
8.
石杉碱甲(1)是从中草药石杉属植物千层塔(Lycopodium serratum Thunb.)中分得的一种高效可逆的乙酰胆碱酯酶抑制剂,临床试验证实它对早老性痴呆症有显著疗效。本文报道N-甲基吡啶酮石杉碱甲类似物2和3的合成。2-甲氧基-5-甲氧羰基-11-亚甲基-5,9-甲撑环辛-7-烯并吡啶(9)在乙腈中用三甲基氯硅烷和碘化钠选择性脱保护以定量的产率得吡啶酮10,再用甲醇钠和碘甲烷甲基化得N-甲基吡啶酮11,11经碱性水解,Curtius重排和氨基的脱保护得N-甲基吡啶酮石杉碱甲类似物2。通过类似的途径从中间体2-甲氧基-5-甲氧羰基-7-甲基-11-酮-5,9-甲撑环辛-7-烯并吡啶(14)合成了类似物3。类似物2和3的乙酰胆碱酯酶抑制活性均低于天然石杉碱甲。  相似文献   
9.
10.
J. Hull  P. Vervaart  K. Grimwood    P. Phelan 《Thorax》1997,52(6):557-560
BACKGROUND: It has been suggested that oxidative stress contributes to lung injury in cystic fibrosis. There is, however, no direct evidence of increased pulmonary oxidative stress in cystic fibrosis nor of the effects of inflammation on the major pulmonary antioxidant, glutathione. A study was undertaken to measure these parameters in infants and young children in the presence or absence of pulmonary inflammation. METHODS: Thirty two infants and young children with cystic fibrosis of mean (SD) age 21.4 (15.3) months (range 2-54) and seven non-cystic fibrosis control subjects of mean (SD) age 21.0 (21.2) months (range 2-54) were studied using bronchoalveolar lavage (BAL). On the basis of the BAL findings the cystic fibrosis group was divided into those with (CF-I) and those without pulmonary inflammation (CF- NI). Levels of lipid hydroperoxide, total glutathione, and gamma- glutamyl transpeptidase (gamma-GT) were then measured in the BAL fluid. RESULTS: The concentrations of lipid hydroperoxide and gamma-GT in the epithelial lining fluid were significantly increased in the CF-I group compared with the control and CF-NI groups, each of which had similar values for these parameters (ratio of geometric means for CF-I group versus control for lipid hydroperoxide 5.4 (95% confidence interval (CI) 1.8 to 15.8) and for gamma-GT 5.2 (95% CI 1.4 to 19.4)). The glutathione concentration tended to be lower in the CF-I subjects but the difference did not reach statistical significance. CONCLUSIONS: These results demonstrate that the airways in patients with cystic fibrosis are exposed to increased oxidative stress which appears to be a consequence of pulmonary inflammation rather than part of the primary cystic fibrosis defect. The increase in gamma-GT in the CF-I group suggests a mechanism by which extracellular glutathione could be utilised by airway epithelial cells.


  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