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   1572篇
  免费   64篇
  国内免费   2篇
耳鼻咽喉   7篇
儿科学   41篇
妇产科学   16篇
基础医学   172篇
口腔科学   28篇
临床医学   173篇
内科学   327篇
皮肤病学   66篇
神经病学   164篇
特种医学   37篇
外科学   193篇
综合类   10篇
一般理论   2篇
预防医学   187篇
眼科学   33篇
药学   95篇
中国医学   1篇
肿瘤学   86篇
  2024年   8篇
  2023年   14篇
  2022年   22篇
  2021年   28篇
  2020年   30篇
  2019年   46篇
  2018年   45篇
  2017年   34篇
  2016年   39篇
  2015年   34篇
  2014年   48篇
  2013年   55篇
  2012年   88篇
  2011年   91篇
  2010年   46篇
  2009年   53篇
  2008年   82篇
  2007年   115篇
  2006年   86篇
  2005年   89篇
  2004年   78篇
  2003年   78篇
  2002年   63篇
  2001年   31篇
  2000年   15篇
  1999年   24篇
  1998年   16篇
  1997年   9篇
  1996年   20篇
  1995年   9篇
  1994年   10篇
  1992年   12篇
  1991年   11篇
  1990年   9篇
  1989年   15篇
  1987年   11篇
  1986年   10篇
  1985年   14篇
  1984年   7篇
  1983年   14篇
  1982年   15篇
  1981年   10篇
  1980年   9篇
  1979年   10篇
  1978年   8篇
  1977年   10篇
  1976年   8篇
  1973年   7篇
  1972年   6篇
  1966年   9篇
排序方式: 共有1638条查询结果,搜索用时 0 毫秒
61.
OBJECTIVES: This study investigated whether previous findings of an increased risk of gliomas among workers in some pulp and paper mills could be confirmed for all Swedish pulp and paper mill workers and whether the increase could be attributed to certain occupational groups. METHODS: The study was based on the Swedish Cancer Environment Register, which links the incidence of cancer from 1971 to 1990 and the 1960 and 1970 census data on codes of occupation and industry for the whole population. Standardized incidence ratios (SIR) were used to estimate the risks for men in different occupations in pulp (N = 28,142) and paper (N = 39,169) mills in 1960, 1970 or both years as compared with those of all gainfully employed men in Sweden. RESULTS: Maintenance workers employed in pulp or paper mills in 1960, 1970 or both years, as well aspulp workers, showed an increased incidence of gliomas in 1971-1990 [SIR 1.5, 95% confidence interval (95% CI) 1.1-2.1 and SIR 1.5,95% CI 1.0-2.2, respectively], whereas the incidence among process workers in paper mills was lower than expected (SIR 0.6, 95% CI 0.3-0.9). Taken together, all employed men in the pulp mill industry had an increased incidence of gliomas (SIR 1.3, 95% CI 1.0-1.7). CONCLUSIONS: Pulp mill workers, but not paper mill workers, were found to have more gliomas in 1971-1990 than expected. There was an increased risk of gliomas among maintenance workers in both pulp and paper mills. Few risk factors for brain tumors are recognized, and the causes of the increase are not obvious.  相似文献   
62.
63.
64.
65.
Tor Langeland 《Allergy》1983,38(6):399-412
The occurrence of proteins cross-reacting with allergens in hen's egg white was studied in turkey, duck, goose and seagull egg whites, in hen egg yolk, and in hen and chicken sera and flesh. The study was based upon quantitative immunoelectrophoretic techniques. The different egg whites were all found to contain proteins cross-reacting with most of the allergens in hen's egg white, but the degree of cross-reactivity varied considerably among the various egg whites. All egg whites contained proteins able to bind human IgE-antibody in the sera of patients with allergy to hen's egg white. Several proteins cross-reacting with allergens in hen's egg white were also detected in egg yolk and in hen and chicken sera and flesh. Clinical implications of the results are discussed.  相似文献   
66.
Maladjustment, with social and mental dysfunction, is one of the most prevalent health problems threatening children in many countries. A method for the early identificantion of maladjusted schoolchildren is described and evaluated. The method involves the completion of a questionnaire for each child by the teacher and the calculation of a test score based on a set of weighting factors assigned to each question. The factors are determined by discriminant analysis. For a proper evaluation of the method an independent clinical assessment of maladjustment among 524 school children was performed, making calculations of specificity and sensitivity possible.  相似文献   
67.
Abstract During 1974 and 1975 a sample of individuals in Sweden between 20 and 60 years were interviewed about dental care habits. 938 oft them were then clinically examined. An estimation of the time needed for treatment of dental caries and periodontitis was based upon the clinical examination. Dental status and the estimated treatment time were then related to the dental care carried out during one period of 18 months and one of 48 months after the clinical examination. For these calculations, information on dental care was acquired from the patient register of the National Social Insurance Board. The results derived from the analyses showed that the requisite time for treating caries related well to the treatment executed. On the other hand the time for treating periodontal disease showed a poorer agreement with what could have been expected from the clinical periodontal status. The treatment time devoted to periodontal disease was considerably higher in the metropolitan areas, with their higher density of dentists, than in other parts of Sweden. Thus, dental care in Sweden between 1974 and 1978 concentrated primarily on restorative procedures while a progression of periodontal disease was largely ignored by dental practitioners.  相似文献   
68.
In a series of 110 liveborn infants who died within 24 h of birth, and six 14- to 17-week-old fetuses, the development of perirenal brown fat was studied by morphometric and biomathematical methods. Brown fat was present at the 20th week of age and, taking as index of maturity the population of multilocular adipocytes, its development progressed according to a 3-parametric logistic growth function, with a half-time of 26 weeks and a tendency to asymptotic stabilization by the 35th week. Unilocular adipocytes appeared early and their low percentage (10.9%) remained relatively stable. Brown fat development in 75% of the cases of small-for-dates corresponded to that of infants with matched postconceptional age but appropriate birth weight. Abnormal cases presented whether a persistence of immature patterns or an unusual predominance of unilocular cells. No changes due to lipolysis were detected in any case.  相似文献   
69.
A 42-year-old male with a history of chronic aortic valve disease and urethra stenosis, was admitted with fever, dysuria, and vomiting. Escherichia coli (E. coli) was cultured from blood and urine. Repeated transesophageal echocardiographic studies performed during the early phase of the hospitalization did not exclude the possibility of infective endocarditis. A definite diagnosis was, however, not established until 6 weeks after admission. At that time a large paravalvular aortic abscess cavity had developed and urgent surgery was necessary. A possible explanation for the delayed diagnostic evaluation was the low level of suspicion, as the septicemia was believed to originate from the urinary tract, without involvement of other organs. The possibility of endocarditis due to E. coli should be considered, especially in subjects with underlying cardiac valve disease, despite an alternative source of septicemia and despite the rarity of this condition. Frequent echocardiographic studies are recommended since extensive tissue destruction may occur without any striking symptoms.  相似文献   
70.
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