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   514220篇
  免费   34040篇
  国内免费   620篇
耳鼻咽喉   6901篇
儿科学   16864篇
妇产科学   13528篇
基础医学   85161篇
口腔科学   14501篇
临床医学   44418篇
内科学   93799篇
皮肤病学   12158篇
神经病学   36222篇
特种医学   18528篇
外国民族医学   63篇
外科学   77287篇
综合类   8478篇
一般理论   118篇
预防医学   38972篇
眼科学   12138篇
药学   40571篇
中国医学   1006篇
肿瘤学   28167篇
  2018年   4943篇
  2015年   4528篇
  2014年   6080篇
  2013年   9587篇
  2012年   12909篇
  2011年   14316篇
  2010年   8324篇
  2009年   7799篇
  2008年   13736篇
  2007年   14747篇
  2006年   15011篇
  2005年   14430篇
  2004年   14107篇
  2003年   13453篇
  2002年   13339篇
  2001年   24124篇
  2000年   25143篇
  1999年   20599篇
  1998年   5459篇
  1997年   4730篇
  1996年   5061篇
  1995年   4634篇
  1994年   4326篇
  1993年   4145篇
  1992年   15747篇
  1991年   16326篇
  1990年   16436篇
  1989年   15807篇
  1988年   14582篇
  1987年   14432篇
  1986年   13606篇
  1985年   12986篇
  1984年   9636篇
  1983年   8253篇
  1982年   4563篇
  1981年   4234篇
  1979年   9430篇
  1978年   6863篇
  1977年   5778篇
  1976年   5607篇
  1975年   6402篇
  1974年   7644篇
  1973年   7134篇
  1972年   6964篇
  1971年   6688篇
  1970年   6174篇
  1969年   5899篇
  1968年   5568篇
  1967年   5015篇
  1966年   4453篇
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
121.
122.
Published data devoted to making and characterization of the properties of polymeric wound dressings with proteolytic action are reviewed. These data are indicative of individual dependence of the physicochemical properties, activity, and stability of each particular enzyme on the type of polymer matrix and the method of immobilization. In order to obtain wound dressings, which are active in physiological medium and retain their activity upon sterilization, it is necessary to optimize the composition and characteristics of a polymer matrix and the enzyme included into its structure. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 8, pp. 24–28, August, 2006.  相似文献   
123.
There is increasing evidence that the assessment of eosinophilic airway inflammation using induced sputum and measurement of airway hyperresponsiveness provides additional, clinically important information concerning asthma control. The aim of this study was to directly compare the effects of different treatments on these markers in patients with asthma and persistent symptoms, despite the use of low-dose inhaled corticosteroids. A double-blind four-way crossover study was performed, which compared a 1-month treatment with budesonide 400 mug b.i.d., additional formoterol, additional montelukast and placebo in 49 patients with uncontrolled asthma despite budesonide 100 mug b.i.d., with each treatment separated by a 4-week washout period. The change in sputum eosinophil count with formoterol (2.4 to 3.8% change, 0.6-fold reduction, 95% confidence interval (CI) 0.5-0.9) differed significantly from placebo (2.8 to 2.5% change, 1.1-fold reduction, 95% CI 0.7-1.6) and high-dose budesonide (2.7 to 1.6% change, 1.6-fold reduction, 95% CI 1.2-2.2). The effects of montelukast did not differ from placebo. The changes in methacholine airway responsiveness were small and did not differ between treatments. High-dose budesonide had the broadest range of beneficial effects on other outcomes, including symptom scores, morning peak expiratory flow and forced expiratory volume in one second. In conclusion, treatment given in addition to low-dose inhaled corticosteroids results in modest benefits. Formoterol and high-dose budesonide have contrasting effects on eosinophilic airway inflammation.  相似文献   
124.
An increase in chronic beryllium disease (CBD) has been suggested due to higher industrial use of beryllium alloys. Since occupational CBD is a perfect phenocopy of sarcoidosis, it might be misdiagnosed as sarcoidosis. In the current it was hypothesised that CBD exists in cohorts of sarcoidosis patients. In a prospective case study, sarcoidosis patients were evaluated for potential beryllium exposure. In those patients in whom beryllium exposure was confirmed and beryllium hypersensitivity demonstrated, the diagnosis of sarcoidosis was rejected and corrected to CBD. In 84 patients seen for re-evaluation or making a diagnosis of sarcoidosis, beryllium exposure was recognised and a diagnosis of CBD was made in 34 out of 84 patients. The time lag between clinical diagnosis of sarcoidosis and the final diagnosis of CBD ranged 0-18 yrs (median 3 yrs) and the mean (range) age at time of diagnosis of CBD was 43.9(25-80) yrs. Beryllium-contaminated workplaces causing disease encompassed a wide spectrum of industries and technical trades in which beryllium-exposure is generally not perceived as a health hazard. In conclusion, chronic beryllium disease still belongs to the spectrum of differential diagnoses of granulomatous disorders.  相似文献   
125.
126.
127.
128.
129.
Severe adverse effects during the use of ovulation inhibitors occur mostly in women who have an elevated risk for the development of certain diseases owing to hereditary or acquired factors. By means of a careful personal or family history analysis as well as specific laboratory examinations, an existing predisposition may frequently be diagnosed and the individual risk associated with the use of oral contraceptive inhibitors may be estimated. The present contribution describes the potential effects of treatment with ovulation inhibitors on women with thrombophilia, cardiovascular disease, diabetes mellitus, dyslipidemia, overweight or underweight, tumors, psychiatric and neurological diseases and autoimmune disease. The hormonal methods and non-hormonal alternatives available for contraception are elucidated according to existing lesions and risk factors and the advantages and disadvantages are discussed.  相似文献   
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