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   1601688篇
  免费   131527篇
  国内免费   2582篇
耳鼻咽喉   21656篇
儿科学   52932篇
妇产科学   46226篇
基础医学   227767篇
口腔科学   47201篇
临床医学   140908篇
内科学   314767篇
皮肤病学   34090篇
神经病学   130114篇
特种医学   64724篇
外国民族医学   474篇
外科学   243793篇
综合类   39717篇
现状与发展   3篇
一般理论   549篇
预防医学   122867篇
眼科学   36470篇
药学   121274篇
  3篇
中国医学   2974篇
肿瘤学   87288篇
  2018年   14766篇
  2016年   12900篇
  2015年   15028篇
  2014年   20646篇
  2013年   31352篇
  2012年   42547篇
  2011年   44751篇
  2010年   26338篇
  2009年   25304篇
  2008年   43003篇
  2007年   45246篇
  2006年   46058篇
  2005年   44673篇
  2004年   44092篇
  2003年   42180篇
  2002年   41293篇
  2001年   75683篇
  2000年   78325篇
  1999年   66388篇
  1998年   17731篇
  1997年   16335篇
  1996年   16314篇
  1995年   16020篇
  1994年   15070篇
  1993年   14217篇
  1992年   55427篇
  1991年   53776篇
  1990年   52566篇
  1989年   50832篇
  1988年   47224篇
  1987年   46561篇
  1986年   44284篇
  1985年   42844篇
  1984年   32035篇
  1983年   27565篇
  1982年   16144篇
  1981年   14436篇
  1980年   13564篇
  1979年   30462篇
  1978年   21068篇
  1977年   17764篇
  1976年   16697篇
  1975年   17575篇
  1974年   21487篇
  1973年   20672篇
  1972年   18854篇
  1971年   17770篇
  1970年   16289篇
  1969年   15269篇
  1968年   13950篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
122.
123.
This study surveyed male and female athletes from 22 midwesterncolleges and universities regarding behaviors and attitudesassociated with anorexia nervosa and bulimia nervosa. The responserate was 66% (N= 695) and the findings indicated that the bodyimage of some athletes may be distorted; one-seventh perceivedthemselves as fat even though they were not. Many athletes seemedpreoccupied with food and weight; almost one-third reportedroutinely thinking about food and weight and more than one-thirdreported dramatic annual weight fluctuations (9 lb or greater)related to bingeing and fasting. Athletes also did not feelin control when they ate and their habits related to food consumptionappeared to be extreme; one-tenth reported a lack of controlwhen they ate, more than one-third binged, one-twentieth ateuntil they were physically ill, and a similar proportion preferrednot to eat in the presence of others. In addition, it was foundthat as many men as women athletes reported these perceptionsbut significant sex differences were noted for specific items.It was suggested that behaviors and attitudes be viewed on acontinuum with normals at one end, eating disordered individuals at the other end,and college athletes in between. Health education that focuseson behaviors and attitudes as symptoms of eating disorders wasrecommended for athletes and those working closely with athletes.Future research was suggested to determine reasons for the undesirablebehaviors and attitudes and to study the onset, development,long-term effects and whether these behaviors and attitudeslead to an eating disorder.  相似文献   
124.
125.
126.
Eight-eight female weanling Sprague-Dawley rats were fed diets containing either 650 or 150 mg magnesium/kg diet and 7.0 or 3.5 mg pyridoxine-HCl/kg diet, in a 2 x 2 factorial arrangement, during growth, gestation, and lactation. The objective of the study was to determine whether concurrent dietary deficiencies of magnesium and pyridoxine were synergistic, additive, or antagonistic with regards to effects on reproductive performance, growth, and development of offspring, and tissue content of magnesium and calcium. Body weight of dams and pups was not different between groups until day 9 of lactation, at which point those animals in either low magnesium group weighed less than the other. Litter size and birth weight were not different. Development, as measured by timing of unfolding of the external ear, opening of both eyes, and clinical emergence of incisors, was delayed in pups from litters in the low magnesium groups. A synergistic effect on delay of onset of ear unfolding by deficiency of both magnesium and pyridoxine was observed. Calcium content of heart and kidney from dams was increased in the low magnesium groups. Renal calcium was not further increased by the level of pyridoxine deficiency in this study. The calcium to magnesium ratio in heart from pups was higher in those from litters in the low magnesium and pyridoxine group than in the others. Results indicate that simultaneous deficiencies of magnesium and pyridoxine may impair function synergistically. Because these two nutrients are often reported to be presented in inadequate amounts in diets of women in their reproductive years, the potential exists for impaired reproductive success.  相似文献   
127.
128.
In transmitting the body's weight, the ankle is subject to frequent static and dynamic injury due to concentrated stresses during standing and movement. The frequency of athletic ankle injuries ranges from 10 to 90 percent, with the highest rate occurring in basketball players. There is prolonged disability and recurrent instability for months to years for 25 to 40 per cent of these patients. Because most of this trauma is handled by primary care physicians, this review presents the mechanism of injury, relevant anatomy, physical examination, and appropriate therapeutic intervention in the acute and rehabilitative phases.  相似文献   
129.
130.
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