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   1601946篇
  免费   131555篇
  国内免费   2583篇
耳鼻咽喉   21646篇
儿科学   52947篇
妇产科学   46229篇
基础医学   227798篇
口腔科学   47202篇
临床医学   140921篇
内科学   314838篇
皮肤病学   34119篇
神经病学   130107篇
特种医学   64733篇
外国民族医学   474篇
外科学   243835篇
综合类   39712篇
现状与发展   3篇
一般理论   544篇
预防医学   122876篇
眼科学   36525篇
药学   121279篇
  3篇
中国医学   2975篇
肿瘤学   87318篇
  2018年   14775篇
  2016年   12905篇
  2015年   15038篇
  2014年   20661篇
  2013年   31367篇
  2012年   42566篇
  2011年   44779篇
  2010年   26349篇
  2009年   25319篇
  2008年   43015篇
  2007年   45263篇
  2006年   46074篇
  2005年   44691篇
  2004年   44106篇
  2003年   42198篇
  2002年   41302篇
  2001年   75689篇
  2000年   78341篇
  1999年   66392篇
  1998年   17734篇
  1997年   16339篇
  1996年   16317篇
  1995年   16019篇
  1994年   15071篇
  1993年   14221篇
  1992年   55430篇
  1991年   53778篇
  1990年   52562篇
  1989年   50833篇
  1988年   47223篇
  1987年   46562篇
  1986年   44285篇
  1985年   42844篇
  1984年   32034篇
  1983年   27566篇
  1982年   16145篇
  1981年   14438篇
  1980年   13564篇
  1979年   30460篇
  1978年   21064篇
  1977年   17765篇
  1976年   16697篇
  1975年   17574篇
  1974年   21488篇
  1973年   20673篇
  1972年   18854篇
  1971年   17771篇
  1970年   16290篇
  1969年   15268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