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   1644140篇
  免费   134689篇
  国内免费   2669篇
耳鼻咽喉   22087篇
儿科学   54540篇
妇产科学   47370篇
基础医学   232824篇
口腔科学   47633篇
临床医学   146508篇
内科学   322468篇
皮肤病学   34982篇
神经病学   134469篇
特种医学   65528篇
外国民族医学   474篇
外科学   248015篇
综合类   40059篇
现状与发展   4篇
一般理论   627篇
预防医学   128973篇
眼科学   37218篇
药学   124218篇
  35篇
中国医学   3026篇
肿瘤学   90440篇
  2018年   16379篇
  2016年   14194篇
  2015年   16375篇
  2014年   22533篇
  2013年   33829篇
  2012年   46280篇
  2011年   48463篇
  2010年   28359篇
  2009年   26996篇
  2008年   45893篇
  2007年   48043篇
  2006年   48662篇
  2005年   47115篇
  2004年   46229篇
  2003年   43944篇
  2002年   42866篇
  2001年   75866篇
  2000年   78438篇
  1999年   66567篇
  1998年   17984篇
  1997年   16514篇
  1996年   16453篇
  1995年   16137篇
  1994年   15158篇
  1993年   14297篇
  1992年   55483篇
  1991年   53815篇
  1990年   52605篇
  1989年   50874篇
  1988年   47248篇
  1987年   46578篇
  1986年   44304篇
  1985年   42865篇
  1984年   32065篇
  1983年   27596篇
  1982年   16160篇
  1981年   14450篇
  1980年   13581篇
  1979年   30470篇
  1978年   21080篇
  1977年   17777篇
  1976年   16704篇
  1975年   17588篇
  1974年   21489篇
  1973年   20687篇
  1972年   18863篇
  1971年   17777篇
  1970年   16292篇
  1969年   15272篇
  1968年   13950篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
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   
133.
134.
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   
135.
136.
137.
One of our patients had trouble maintaining therapeutic and safe levels of theophylline, even though we were careful in planning and monitoring her drug regimen. This case report shows how we were able to use principles of pharmacokinetics to distinguish among plausible explanations for her experience. We discovered that she was not taking the drug consistently as prescribed and that supervised administration resolved apparent contradictions between doses and serum levels. We believe that physicians can use the same information and methods that we used to get better and safer results from theophylline therapy.  相似文献   
138.
139.
Herpes zoster probably occurs more often than generally thought. Since it produces a radicular distribution of pain, it should be included in the differential diagnosis of radiculopathy. A case is presented in which evaluating the radicular low back pain before the characteristic rash appears was misleading. Careful history-taking concerning the exact nature of the pain and sensory changes is needed to differentiate between zoster and radiculopathy, if no rash is evident.  相似文献   
140.
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