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   900596篇
  免费   63708篇
  国内免费   2332篇
耳鼻咽喉   12523篇
儿科学   28732篇
妇产科学   26179篇
基础医学   126882篇
口腔科学   24737篇
临床医学   75010篇
内科学   183574篇
皮肤病学   19013篇
神经病学   71585篇
特种医学   36546篇
外国民族医学   336篇
外科学   142448篇
综合类   19050篇
一般理论   248篇
预防医学   64685篇
眼科学   20183篇
药学   63935篇
中国医学   1801篇
肿瘤学   49169篇
  2018年   9083篇
  2017年   7202篇
  2016年   7710篇
  2015年   8755篇
  2014年   12415篇
  2013年   19257篇
  2012年   25742篇
  2011年   27352篇
  2010年   16638篇
  2009年   15830篇
  2008年   26211篇
  2007年   27832篇
  2006年   28015篇
  2005年   27549篇
  2004年   26396篇
  2003年   25562篇
  2002年   25148篇
  2001年   41436篇
  2000年   42611篇
  1999年   36323篇
  1998年   10006篇
  1997年   9173篇
  1996年   9111篇
  1995年   8463篇
  1994年   8097篇
  1993年   7598篇
  1992年   28253篇
  1991年   27018篇
  1990年   26444篇
  1989年   25376篇
  1988年   23591篇
  1987年   23202篇
  1986年   22288篇
  1985年   21183篇
  1984年   15835篇
  1983年   13505篇
  1982年   8112篇
  1979年   14610篇
  1978年   10223篇
  1977年   8639篇
  1976年   8157篇
  1975年   8969篇
  1974年   10712篇
  1973年   10199篇
  1972年   9671篇
  1971年   8935篇
  1970年   8591篇
  1969年   8036篇
  1968年   7695篇
  1967年   7092篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.

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   
93.
94.
95.
96.
97.
This study aimed at deriving occupational thresholds of toxicological concern for inhalation exposure to systemically-acting organic chemicals using predicted internal doses. The latter were also used to evaluate the quantitative relationship between occupational exposure limit and internal dose. Three internal dose measures were identified for investigation: (i) the daily area under the venous blood concentration vs. time curve, (ii) the daily rate of the amount of parent chemical metabolized, and (iii) the maximum venous blood concentration at the end of an 8-hr work shift. A dataset of 276 organic chemicals with 8-hr threshold limit values-time-weighted average was compiled along with their molecular structure and Cramer classes (Class I: low toxicity, Class II: intermediate toxicity, Class III: suggestive of significant toxicity). Using a human physiologically-based pharmacokinetic model, the three identified dose metrics were predicted for an 8-hr occupational inhalation exposure to the threshold limit value for each chemical. Distributional analyses of the predicted dose metrics were performed to identify the percentile values corresponding to the occupational thresholds of toxicological concern. Also, simple linear regression analyses were performed to evaluate the relationship between the 8-hr threshold limit value and each of the predicted dose metrics, respectively. No threshold of toxicological concern could be derived for class II due to few chemicals. Based on the daily rate of the amount of parent chemical metabolized, the proposed internal dose-based occupational thresholds of toxicological concern were 5.61?×?10?2 and 9?×?10?4 mmol/d at the 10th percentile level for classes I and III, respectively, while they were 4.55?×?10?1 and 8.5?×?10?3 mmol/d at the 25th percentile level. Even though high and significant correlations were observed between the 8-hr threshold limit values and the predicted dose metrics, the one with the rate of the amount of chemical metabolized was remarkable regardless of the Cramer class (r2 = 0.81; n = 276). The proposed internal dose-based occupational thresholds of toxicological concern are potentially useful for screening-level assessments as well as prioritization within an integrated occupational risk assessment framework.  相似文献   
98.
99.
100.
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