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   3185篇
  免费   407篇
  国内免费   4篇
耳鼻咽喉   6篇
儿科学   109篇
妇产科学   63篇
基础医学   137篇
口腔科学   68篇
临床医学   170篇
内科学   456篇
皮肤病学   22篇
神经病学   74篇
特种医学   182篇
外科学   163篇
综合类   15篇
预防医学   1929篇
眼科学   14篇
药学   82篇
肿瘤学   106篇
  2023年   36篇
  2022年   57篇
  2021年   41篇
  2020年   95篇
  2019年   43篇
  2018年   116篇
  2017年   110篇
  2016年   103篇
  2015年   96篇
  2014年   98篇
  2013年   173篇
  2012年   51篇
  2011年   57篇
  2010年   132篇
  2009年   137篇
  2008年   85篇
  2007年   81篇
  2006年   92篇
  2005年   72篇
  2004年   59篇
  2003年   49篇
  2002年   108篇
  2001年   114篇
  2000年   81篇
  1999年   156篇
  1998年   167篇
  1997年   200篇
  1996年   214篇
  1995年   134篇
  1994年   57篇
  1993年   124篇
  1992年   28篇
  1991年   20篇
  1990年   33篇
  1989年   47篇
  1988年   41篇
  1987年   31篇
  1986年   39篇
  1985年   26篇
  1984年   14篇
  1983年   19篇
  1982年   18篇
  1981年   17篇
  1980年   13篇
  1979年   12篇
  1978年   10篇
  1977年   10篇
  1976年   17篇
  1975年   10篇
  1969年   8篇
排序方式: 共有3596条查询结果,搜索用时 15 毫秒
51.
52.
53.
Objective To develop and validate a consensus set of retrieval categories for how children remember what they have eaten, and to relate retrieval categories to accuracy of reporting items eaten during school lunch.Design A Delphi technique study was conducted using 10 psychologists. The subject matter consisted of responses transcribed from interviews conducted with 89 randomly selected fourth graders within 90 minutes of eating. Retrieval categories were evaluated for accuracy by comparing students’ self-reported lunch intake with observation.Statistical analyses For round 1, a centroid hierarchical cluster analysis was used to identify common sets of rating pairs to propose categories for reaching consensus. For rounds 2 and 3, percent of agreement was calculated. Accuracy was tabulated across meal items and student use by retrieval category.Results After round 3, we found that 23 “near-consensus”categories were used by at least eight raters. Six categories were used 60% of the time, 4 were used 20% of the time, and 5 were used 15% of the time. Less frequently used categories were combined with similar, more frequently used categories for a total of 16 categories. Students used a large variety of retrieval categories when accurately reporting consumption. Of the 16 categories, 12 were used similarly by both accurate and inaccurate students. Where there were differences in accuracy by retrieval category, the more accurate students used “taste/smell/texture”and “visual”in deference to “order items consumed”and “oral cue still present.”Applications These categories provide insight into the broad range of retrieval categories that children use and provide direction for researchers to design and study specific cues to enhance the accuracy of children's self-reports of diet. J Am Diet Assoc. 1997;97:31–36.  相似文献   
54.
55.
56.
57.
Objective To assess the accuracy of several published equations for predicting basal metabolic rate (BMR) in older women.

Design BMR was assessed in 116 healthy, older white women, aged 60 to 82 years, on three successive mornings by indirect calorimetry. Body composition was determined by dual energy X-ray absorptiometry or hydrostatic weighing. The measured BMRs were compared with values obtained from eight published prediction equations that used solely, or in various combinations, measures of height, weight, fat-free mass, age, and menopausal status.

Statistical analyses performed The root mean squared prediction error (RMSPE) was used to determine how accurately predicted BMR matched actual BMR for each subject. In addition, regression analysis was used to evaluate accuracy of predicted BMR vs directly measured BMR.

Results Predicted mean BMR determined using all eight equations was significantly correlated to measured BMR (P=.0001), accounting for 30% to 52% of the variance of measured BMR. When analyzed by RMSPE, however, the equations of Owen et al (1986), Fredrix et al (1990), and Harris-Benedict (1919) predicted actual BMR for each subject within an average of 116 kcal/day, and the equation of Cunningham (1980) resulted in the largest prediction error at 208 kcal/day.

Applications/conclusions The regression equations of Owen et al (1986), which used body weight, Fredrix et al (1990), which used body weight and age, and Harris-Benedict (1919), which used age, weight, and height as variables, were most accurate in predicting BMR in our sample of healthy older women. J Am Diet Assoc. 1995; 95:1387-1392.  相似文献   

58.
59.
OBJECTIVE: To evaluate the success of the Southeast Asian Health Project in terms of client satisfaction with the prenatal care and other services. To obtain additional data about Southeast Asian women's health practices regarding childbearing. DESIGN: Survey through questionnaires administered as interviews. SETTING: In clients' homes or via telephone. PARTICIPANTS: 119 women from SEAHP's case files of recently delivered clients. MEASUREMENTS AND MAIN RESULTS: Interviews were conducted by four community workers fluent in Cambodian or Lao. The majority of women were satisfied with SEAHP, particularly the interpretation and education in native languages. Women were also satisfied with SEAHP, encouraging others to seek care. CONCLUSIONS: SEAHP appears to meet prenatal care needs of Southeast Asian women in Long Beach, California. More objective outcome data await analyses, but the program's approach may ensure access to and use of health services.  相似文献   
60.
The benefits of regular physical activity in older persons are numerous and well established. Regular physical activity in older adults is associated with an overall improvement in health, functional capacity, quality of life, and independence. Many questions arise for healthcare providers regarding an older person’s ability and motivation to be physically active. The healthcare provider has a unique opportunity to assess the older client’s incentives, preferences, and abilities for physical activities, as well as to prescribe a safe, appropriate, and enjoyable exercise plan. The exercise precription can be simple yet thorough enough to ensure benefits in an older person’s health and functional capacity.  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