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   1280399篇
  免费   98198篇
  国内免费   1993篇
耳鼻咽喉   18440篇
儿科学   44424篇
妇产科学   35036篇
基础医学   182370篇
口腔科学   33621篇
临床医学   111416篇
内科学   258723篇
皮肤病学   28064篇
神经病学   100462篇
特种医学   51274篇
外国民族医学   660篇
外科学   196687篇
综合类   27133篇
现状与发展   1篇
一般理论   378篇
预防医学   95832篇
眼科学   27958篇
药学   94928篇
  2篇
中国医学   2433篇
肿瘤学   70748篇
  2018年   13163篇
  2017年   9996篇
  2016年   10940篇
  2015年   12413篇
  2014年   17215篇
  2013年   26272篇
  2012年   36120篇
  2011年   38183篇
  2010年   22860篇
  2009年   21864篇
  2008年   36713篇
  2007年   39336篇
  2006年   39589篇
  2005年   38520篇
  2004年   37669篇
  2003年   36501篇
  2002年   35845篇
  2001年   64028篇
  2000年   66546篇
  1999年   56442篇
  1998年   15146篇
  1997年   13772篇
  1996年   14207篇
  1995年   13464篇
  1994年   12776篇
  1993年   11796篇
  1992年   44599篇
  1991年   43484篇
  1990年   42249篇
  1989年   40131篇
  1988年   36918篇
  1987年   36258篇
  1986年   33652篇
  1985年   32297篇
  1984年   24155篇
  1983年   20272篇
  1982年   11733篇
  1981年   10697篇
  1980年   9522篇
  1979年   21366篇
  1978年   14834篇
  1977年   12549篇
  1976年   11701篇
  1975年   12640篇
  1974年   14680篇
  1973年   14143篇
  1972年   12964篇
  1971年   11746篇
  1970年   11064篇
  1969年   10037篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
The sodium, potassium and creatinine contents of three non-consecutive 24-h urine samples collected by 34 selected adult individuals (10 m; 24 f) living in Cork City were determined. The pooled mean 24-h excretion of sodium and potassium in collections adjudged to be complete were 152 mmol and 78 mmol, respectively. There was no significant difference between group average weekday and weekend-day excretion of Na or K, for either males or females. This suggests that weekend 24-h urinary collections, which most subjects find more convenient, are suitable for studies of sodium and potassium intakes of groups. The ratios of intra- to inter-individual variation for 24-h urinary sodium were 1.4 and 2.1 for males and females, respectively. The corresponding ratios for 24-h urinary potassium were 6.6 for males and 4.9 for females. These ratios indicated that there were large individual day-to-day variations in urinary sodium and potassium excretion in this group. It was estimated that a sample size of 35-60 individuals would be required to estimate group mean sodium and potassium intakes by means of single 24-h urine collections.  相似文献   
102.
Vogt-Koyanagi-Harada syndrome and pregnancy   总被引:2,自引:0,他引:2  
Two black women had bilateral anterior and posterior uveitis, nonrhegmatogenous retinal detachments, pleocytosis, headaches, dysacousis, and alopecia. These patients with Vogt-Koyanagi-Harada (VKH) syndrome improved clinically while they were pregnant after the discontinuation of corticosteroid treatment. They developed recurrent symptoms and findings after termination of their pregnancies. We speculate that changes in immunity and humoral constituents during pregnancy account for their remissions. It is important to assess the menstrual history and to avoid pregnancy before initiating steroid treatment for VKH syndrome.  相似文献   
103.
Keloids     
Keloids are benign fibrous growths that result from an abnormal connective tissue response in certain predisposed individuals. Blacks form keloids more often than whites; however, the reason for this racial difference is not known. Trauma, foreign-body reactions, infections, and endocrine dysfunction have all been proposed as precipitating factors. Keloids are found most commonly on the ear lobes, shoulders, upper back, and midchest. They extend past the area of trauma and once present tend to remain stable. Although sometimes pruritic, painful, or tender, they are usually asymptomatic. Histologically, keloids are characterized by thick collagen bundles, abundant mucinous ground substance, few fibroblasts, and few if any foreign-body reactions. Although there have been many therapeutic modalities, most have had limited success. The most commonly used therapeutic approach is a combination of cryotherapy, intralesional steroid injections, surgical excision, and pressure devices.  相似文献   
104.
105.
The role of caffeine or coffee in causing or promoting the incidence of serious disease is equivocal. Two design factors may account for the discrepancies in reported findings on the effects of coffee drinking: (a) imprecision of measurement and (b) confounding variables. A study of 2,714 white U.S. adults disclosed that, of 32 risk factors analyzed by linear and logistic regression, only sex and cigarette smoking were found to be important potential confounders of caffeine and coffee intake. Partial R2 values of the other 30 risk factors were relatively small and were inconsistent for each sex. It is unlikely that any of these factors could explain any of the reported associations between caffeine or coffee consumption and certain diseases. However, certain weak associations with caffeine or coffee intake should be included in the study design when they are known to be risk factors of a disease under investigation. These factors for men are dietary fat intake, vitamin C intake, and body mass index; and for women are vitamin use, alcohol intake, stress, and perceived health status.  相似文献   
106.
107.
108.
109.
In der Behandlung von Frakturen spielt die Analgesie eine wesentliche Rolle. Es stellt sich daher die Frage, ob in der Klinik h?ufig eingesetzte Analgetika wie Tramadol oder Diclofenac negative Wirkungen auf die Knochenbruchheilung haben.  相似文献   
110.
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