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   1097628篇
  免费   73456篇
  国内免费   1392篇
耳鼻咽喉   15215篇
儿科学   35200篇
妇产科学   29189篇
基础医学   156357篇
口腔科学   30174篇
临床医学   97385篇
内科学   208164篇
皮肤病学   24732篇
神经病学   83872篇
特种医学   43728篇
外国民族医学   201篇
外科学   166024篇
综合类   21845篇
现状与发展   1篇
一般理论   282篇
预防医学   76926篇
眼科学   24855篇
药学   87838篇
  7篇
中国医学   2836篇
肿瘤学   67645篇
  2019年   8197篇
  2018年   12112篇
  2017年   9732篇
  2016年   10869篇
  2015年   11850篇
  2014年   15910篇
  2013年   23461篇
  2012年   32245篇
  2011年   34121篇
  2010年   19755篇
  2009年   18340篇
  2008年   31532篇
  2007年   33664篇
  2006年   34151篇
  2005年   32431篇
  2004年   30991篇
  2003年   29717篇
  2002年   28624篇
  2001年   60544篇
  2000年   62109篇
  1999年   51250篇
  1998年   12558篇
  1997年   11097篇
  1996年   11081篇
  1995年   10418篇
  1994年   9429篇
  1993年   8938篇
  1992年   37872篇
  1991年   36377篇
  1990年   35825篇
  1989年   34367篇
  1988年   30957篇
  1987年   30075篇
  1986年   28302篇
  1985年   26586篇
  1984年   19331篇
  1983年   16202篇
  1982年   8917篇
  1979年   17101篇
  1978年   11459篇
  1977年   10277篇
  1976年   8870篇
  1975年   10098篇
  1974年   11671篇
  1973年   11295篇
  1972年   10760篇
  1971年   10102篇
  1970年   9266篇
  1969年   8949篇
  1968年   7928篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
83.
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   
84.
85.
A rotating contact lens holder for the three-mirror Goldmann lens permits circular examination of the fundus or chamber angle without having to change the position of the fingers on the edge of the lens. The contact lens holder consists of an outer polygonal ring hold by the thumber and index finger. An inner rotating ring holds the contact lens. Continuous rotation of the contact lens is performed with the free middle Finger. This device permits circular examination of the retina without interruption of fixation. The instrument improves not only the speed but also the reliability of the examination.  相似文献   
86.
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   
87.
Vaccine cuisine.   总被引:1,自引:0,他引:1       下载免费PDF全文
  相似文献   
88.
89.
Eighty-nine cases of chronic bronchitis were matched against167 asymptomatic controls from the glass bangle industry ofFirozabad. Factors of age, social status, smoking habit andduration of exposure were studied. Duration of exposure wasfound to be a factor contributing significantly to the causationof disease. Requests for reprints should be addressed to: Dr B. N. Gupta, Division of Epidemilogy, Industrial Toxicology Research Centre, Mahatma Gandhi Marg, Lucknow P.O. Box 80, 226001, India  相似文献   
90.
We evaluated the therapeutic efficacy of miconazole (MCZ, Florid-F inj.), a new antifungal agent for parenteral use, in deep-seated fungal infections of respiratory tract system. A daily dose of 400-1,800 mg of MCZ was given intravenously for 12-38 days (mean: 23.4 days) to 7 patients: 2 patients with pulmonary aspergillosis, 1 patient with bronchial aspergillosis, 1 patient with pulmonary candidiasis and 3 patients with candidemia. One additional patient with pulmonary aspergillosis received three instillations of 20 mg of MCZ into the thoracic cavity. The clinical effects were excellent in 1, good in 4 and poor in 3 patients. The efficacy rate was 100% in 5 cases with respiratory fungal infections but 3 cases with candidemia did not respond well to the treatment. Four strains each of Aspergillus sp. and Candida sp. were identified as causative organisms. Seven of the 8 strains were eradicated by administration of MCZ. Side effects observed were irritation and heat in a leg in 1 patient, hyperlipoidemia in 2 patients and eosinophilia in 1 patient. The adverse reactions disappeared after the completion of the therapy. From the above results, we conclude that MCZ is one of the most useful antifungal agents for parenteral use as a first choice on deep-seated fungal infections in the respiratory tract.  相似文献   
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