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   11431篇
  免费   1085篇
  国内免费   16篇
耳鼻咽喉   74篇
儿科学   253篇
妇产科学   316篇
基础医学   1102篇
口腔科学   176篇
临床医学   1006篇
内科学   2490篇
皮肤病学   210篇
神经病学   921篇
特种医学   385篇
外科学   1350篇
综合类   146篇
一般理论   2篇
预防医学   2634篇
眼科学   367篇
药学   570篇
中国医学   2篇
肿瘤学   528篇
  2022年   98篇
  2021年   167篇
  2020年   155篇
  2019年   180篇
  2018年   258篇
  2017年   184篇
  2016年   209篇
  2015年   204篇
  2014年   303篇
  2013年   460篇
  2012年   440篇
  2011年   479篇
  2010年   365篇
  2009年   327篇
  2008年   387篇
  2007年   494篇
  2006年   445篇
  2005年   424篇
  2004年   405篇
  2003年   363篇
  2002年   407篇
  2001年   387篇
  2000年   375篇
  1999年   388篇
  1998年   251篇
  1997年   260篇
  1996年   276篇
  1995年   192篇
  1994年   122篇
  1993年   178篇
  1992年   178篇
  1991年   166篇
  1990年   224篇
  1989年   188篇
  1988年   210篇
  1987年   182篇
  1986年   211篇
  1985年   175篇
  1984年   113篇
  1983年   119篇
  1982年   84篇
  1981年   72篇
  1980年   84篇
  1979年   147篇
  1978年   98篇
  1977年   88篇
  1976年   91篇
  1975年   73篇
  1973年   70篇
  1972年   77篇
排序方式: 共有10000条查询结果,搜索用时 906 毫秒
41.
Objective To examine the relationship of cancer prevention-related nutrition knowledge, beliefs, and attitudes to cancer prevention dietary behavior.Subjects/setting Noninstitutionalized US adults aged 18 years and older.Methods Data collected in the 1992 National Health Interview Survey Cancer Epidemiology Supplement were analyzed. The supplement included questions to ascertain knowledge, beliefs, and attitudes and a food frequency questionnaire to ascertain nutrient intake.Statistics Multivariate linear regression modeling was conducted to assess the hypothesized relationships.Results After adjustment for relevant covariates (age, sex, education, total energy, perceived barriers to eating a more healthful diet), knowledge and belief constructs were predictive of dietary behavior. Specifically, fat, fiber, and fruit and vegetable intakes more closely approximated dietary recommendations for persons with more cancer-prevention knowledge. The strength of the associations between these constructs and dietary behavior varied in some cases according to level of education and perceived barriers to eating a healthful diet. Of the perceived barriers to eating a healthful diet, perceived ease of eating a healthful diet was most strongly and consistently predictive of intake.Conclusions Research findings challenge dietetics practitioners to design diet- and health-promotion programs and activities that not only educate the public about the importance of diet to health, but also address barriers to dietary change.  相似文献   
42.
43.
44.
45.
Influences on the Selection of Dietetics as a Career   总被引:1,自引:0,他引:1  
Objective To gather information on the factors that influence students’ decisions to choose dietetics as a career.Design Self-administered questionnaires regarding the point at which career decisions were made were completed by 1,695 students in Plan IV/V dietetics programs throughout the United States.Subjects All Plan IV/V dietetics programs that reported greater than five graduates in the academic year 1989 to 1990 were selected from the 1990-1991 Directory of Dietetic Programs for the sample population. Of the 156 schools that were mailed questionnaires, responses were received from 84 schools (54%). Almost 90% of the students were women, 10.6% were men.Statistical analyses Data were analyzed using the Statistical Package for the Social Sciences. A χ2 analysis was used to examine the relationship between point of decision and factors that influenced career choice, including people who influence career choice.Results The majority of students (55%) questioned reported making their career decision in college. Students rated interest in nutrition (96.3%) and job enjoyment (93.8%) as factors that were important in their decision to pursue a career in dietetics. College catalogs were rated by 48.3% of the students as being either useful or very useful in helping them make their career selection. With respect to gender differences, women rated a diverse work environment as being very important to their career decision more frequently than men (χ2=15.44, P<.01). Women were more likely than men to rate part-time work opportunities as being very important (χ2=26.75, P<.001); and selected working with people as being very important to their career decision (χ2=17.59, P<.01).Conclusions Findings identified that recruitment strategies need to be audience specific. Because career decision making appears to occur during one of three time frames (high school, college, or work experience), recruitment activities should be developed to specifically target students at these times. One way to increase the exposure of students to the profession of dietetics is for registered dietitians to give guest lectures in introductory college courses and high school upper-class courses in health, home economics, and biology. The use of university/college catalogs as effective marketing tools should also not be underestimated.Data suggest that gender differences exist in factors that influence persons to choose dietetics as a career. To increase the number of men who pursue careers in dietetics, future research should be designed to more fully explore gender differences, so that strategies to recruit more men into the profession can be developed. J Am Diet Assoc. 1997: 97;254–257.  相似文献   
46.
47.
48.
Methods: Efficacy and safety of the topically acting glucocorticosteroid budesonide retention enema (2.3 mg/ 11 5 mL) were compared with prednisolone disodium phosphate enema (31.25 mg/125 mL) in patients with active distal ulcerative colitis. The study was a randomized, multicentre trial, with two parallel groups and single-blind to the investigator. One hundred patients with active ulcerative colitis, not reaching beyond the splenic flexure as determined by endoscopy, were treated for up to 8 weeks. Results: Forty-five patients were randomized to receive budesonide and 5 5 to prednisolone. Both treatment groups improved significantly in terms of endoscopic and histological scoring during the study, but there were no statistically significant differences between the two groups. Clinical remission, defined as no more than three daily bowel movements without blood and endoscopically non-inflamed mucosa, was achieved in 16% of the patients in the budesonide group after four weeks and in 24% in the prednisolone group (N.S.). After 8 weeks treatment the clinical remission rate in the groups had increased to 36 % for budesonide and 47% for prednisolone (N.S.). Mean morning plasma cortisol levels were unchanged in the budesonide group, whereas they were significantly suppressed in the prednisolone group after 2, 4 and 8 weeks (P < 0.0001). Side effects were mild and rare in both groups. Conclusions: Treatment with budesonide enema in active distal ulcerative colitis was comparable, regarding efficacy, to treatment with conventional prednisolone enema. A prolongation of the treatment time from 4 to 8 weeks doubled the clinical remission rate in both groups. However, budesonide may be preferable to prednisolone since it causes less systemic effects as reflected by a lack of plasma cortisol suppression.  相似文献   
49.
50.
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