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   27082篇
  免费   2423篇
  国内免费   37篇
耳鼻咽喉   405篇
儿科学   817篇
妇产科学   761篇
基础医学   3277篇
口腔科学   686篇
临床医学   3092篇
内科学   4439篇
皮肤病学   208篇
神经病学   1837篇
特种医学   963篇
外科学   3811篇
综合类   542篇
一般理论   13篇
预防医学   4774篇
眼科学   441篇
药学   1734篇
中国医学   45篇
肿瘤学   1697篇
  2022年   216篇
  2021年   368篇
  2020年   303篇
  2019年   380篇
  2018年   496篇
  2017年   397篇
  2016年   389篇
  2015年   443篇
  2014年   570篇
  2013年   899篇
  2012年   1132篇
  2011年   1122篇
  2010年   707篇
  2009年   652篇
  2008年   1065篇
  2007年   1150篇
  2006年   1034篇
  2005年   1002篇
  2004年   1030篇
  2003年   930篇
  2002年   942篇
  2001年   959篇
  2000年   920篇
  1999年   852篇
  1998年   513篇
  1997年   526篇
  1996年   519篇
  1995年   431篇
  1994年   266篇
  1993年   304篇
  1992年   620篇
  1991年   530篇
  1990年   522篇
  1989年   517篇
  1988年   506篇
  1987年   450篇
  1986年   492篇
  1985年   473篇
  1984年   371篇
  1983年   315篇
  1982年   219篇
  1981年   206篇
  1980年   221篇
  1979年   355篇
  1978年   244篇
  1977年   231篇
  1974年   232篇
  1973年   205篇
  1972年   201篇
  1969年   201篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
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   
65.
66.
67.
68.
Contact lens disinfection systems were evaluated for their effectiveness in killing Acanthamoeba castellanii and Acanthamoeba polyphaga trophozoites and cysts. Amoebae were inoculated into commercially available contact lens cleaning and soaking solutions. At intervals varying from 30 minutes to 24 hours, solutions were filtered. The filters were removed and cultured for Acanthamoeba organisms. Striking differences were observed in the abilities of the different disinfecting solutions to kill the organisms. Solutions containing chlorhexidine were effective at very short exposure times. Solutions containing benzalkonium chloride required slightly longer exposure times but were faster than solutions containing only thimerosal. Solutions containing sorbate, polyaminopropyl biguanide, or polyquaternium-1 were not effective at killing Acanthamoeba organisms in the time allotted for the experiment. Solutions containing hydrogen peroxide were quite effective if the agent was not prematurely catalyzed. A. polyphaga generally required longer exposure to disinfectants than did A. castellanii for complete inhibition to occur.  相似文献   
69.
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   
70.
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