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   903218篇
  免费   63779篇
  国内免费   2344篇
耳鼻咽喉   12500篇
儿科学   28750篇
妇产科学   26262篇
基础医学   127097篇
口腔科学   24996篇
临床医学   74960篇
内科学   184144篇
皮肤病学   19264篇
神经病学   71700篇
特种医学   36695篇
外国民族医学   336篇
外科学   142912篇
综合类   19051篇
一般理论   247篇
预防医学   64643篇
眼科学   20132篇
药学   64202篇
中国医学   1807篇
肿瘤学   49643篇
  2018年   9152篇
  2017年   7226篇
  2016年   7746篇
  2015年   8804篇
  2014年   12469篇
  2013年   19341篇
  2012年   25826篇
  2011年   27450篇
  2010年   16682篇
  2009年   15892篇
  2008年   26348篇
  2007年   27953篇
  2006年   28122篇
  2005年   27686篇
  2004年   26512篇
  2003年   25716篇
  2002年   25294篇
  2001年   41590篇
  2000年   42788篇
  1999年   36476篇
  1998年   10028篇
  1997年   9200篇
  1996年   9134篇
  1995年   8486篇
  1994年   8122篇
  1993年   7611篇
  1992年   28343篇
  1991年   27118篇
  1990年   26555篇
  1989年   25497篇
  1988年   23670篇
  1987年   23279篇
  1986年   22332篇
  1985年   21237篇
  1984年   15864篇
  1983年   13527篇
  1982年   8116篇
  1979年   14647篇
  1978年   10234篇
  1977年   8650篇
  1976年   8167篇
  1975年   8981篇
  1974年   10736篇
  1973年   10191篇
  1972年   9673篇
  1971年   8932篇
  1970年   8600篇
  1969年   8035篇
  1968年   7705篇
  1967年   7108篇
排序方式: 共有10000条查询结果,搜索用时 343 毫秒
91.
92.
93.
94.

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   
95.
96.
97.
98.
99.
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   
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