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   606309篇
  免费   31522篇
  国内免费   669篇
耳鼻咽喉   7623篇
儿科学   18626篇
妇产科学   14124篇
基础医学   102724篇
口腔科学   15198篇
临床医学   54507篇
内科学   114182篇
皮肤病学   13558篇
神经病学   40713篇
特种医学   21605篇
外国民族医学   53篇
外科学   88054篇
综合类   7969篇
现状与发展   2篇
一般理论   134篇
预防医学   45275篇
眼科学   13369篇
药学   46617篇
  1篇
中国医学   1386篇
肿瘤学   32780篇
  2021年   5052篇
  2019年   5120篇
  2018年   8030篇
  2017年   5608篇
  2016年   6426篇
  2015年   7439篇
  2014年   9289篇
  2013年   13598篇
  2012年   22197篇
  2011年   24200篇
  2010年   13036篇
  2009年   11080篇
  2008年   21456篇
  2007年   23346篇
  2006年   22826篇
  2005年   21926篇
  2004年   21040篇
  2003年   19964篇
  2002年   19192篇
  2001年   23867篇
  2000年   24870篇
  1999年   19887篇
  1998年   5500篇
  1997年   4560篇
  1996年   4592篇
  1995年   4315篇
  1992年   14572篇
  1991年   15958篇
  1990年   16053篇
  1989年   15742篇
  1988年   14388篇
  1987年   14272篇
  1986年   13255篇
  1985年   12781篇
  1984年   9517篇
  1983年   8076篇
  1982年   4280篇
  1979年   8994篇
  1978年   6437篇
  1977年   5192篇
  1976年   5548篇
  1975年   6650篇
  1974年   7470篇
  1973年   7199篇
  1972年   6616篇
  1971年   6326篇
  1970年   5903篇
  1969年   5486篇
  1968年   5164篇
  1967年   4655篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
On the basis of experience with the treatment of more than 1,500 patients with post-burn defects, deformities, and trophic ulcers, the authors distinguished types of affection in which the traditional methods are ineffective. These 133 patients were subjected to plasty with ++cutaneo-fascial grafts; the zones of donor areas from which the grafts are taken are determined. Plasty with ++cutaneo-fascial grafts is indicated in defects of the face, deformity of the neck, total adduction contracture of the arm, defect of the breast, and affections of the hand, leg, and foot. Concrete grafts and the site from which they are taken for restoration of certain regions of the body are suggested. ++Cutaneo-fascial grafts make it possible to restore the shape, function, and the skin of the involved region.  相似文献   
52.
53.
OBJECTIVE: To determine the most frequent clinical causes of a prolonged activated partial thromboplastin time (APTT) result, and to determine whether a new heparin-removal device (the Hepchek, Pall Biomedical, Glen Cove, NY 11542) is capable of efficiently detecting the causes of these values. DESIGN: A combination of chart review and laboratory testing comparing the criterion standard--the heparin chromogenic substrate assay--with the Hepchek. Laboratory investigations were blinded and controlled. SETTING: Inpatient, acute-care hospital. PATIENTS: A total of 1,000 hospital patients with a variety of hemostatic disorders. MAIN OUTCOME MEASURE: The extent to which the Hepchek accurately identified the etiology of a prolonged APTT result. RESULTS: The APTT was prolonged in 25.2% of samples. The presence of heparin in the sample was confirmed by chromogenic assay or by using the Hepchek heparin-removal filter. The presence of heparin was confirmed in 12.8% of all samples and in more than 50% of all abnormal samples. The cause of the abnormal APTT was often unappreciated by the clinician. Bayesian analysis of the Hepchek's ability to diagnose heparin correctly as the cause of the abnormal APTT showed a sensitivity of 100% and specificity of 99.9%. CONCLUSION: Use of the Hepchek in the routine clinical laboratory is an efficient and rapid method of detecting heparin as a cause of isolated prolonged APTT results, and should reduce demands for unwarranted coagulation analyses and inappropriate treatment with blood products.  相似文献   
54.
Using hierarchical cluster analysis, applied to 47 cases of Guillain-Barre Syndrome (GBS) incident in South-West Stockholm (SWS) during the period from January 1973 to June 1992, we identified three major clinicoepidemiological subgroups. The first subgroup, 25.5% of the cases (26.7 ± 6.7 years), recorded a peak incidence at ages 20–29 years and presented significant differences from other subgroups, a high proportion of cases with onset at low age preceded by respiratory infection (83.3%) and with normal motor conduction velocity (50.0%). Also found, were less affected biological parameters, a rapidly progressive course and independence in gait at one month after onset. A second subgroup, 27.7% of cases, was severely affected, clinically and functionally. It consisted predominantly of young individuals (22.7 ± 11.1 years), with a high incidence (69.2% of cases) in autumn. A third subgroup, comprising 40.47; of cases, was older (61.1 ± 11.0 years) and, in general, also severely affected. The incidence of this form appeared to be invariant with time.  相似文献   
55.
56.
In experiments on albino rats it was established that three administrations of indomethacin in a dose of 0.01 g/kg body weight induced a severe damage of the liver characterized by disturbances of hepatocytic membranes, bile-producing and protein-producing functions of the liver, an enhancement of lipid peroxidation, a decrease of reduced glutathione pool. Antioxidants (tocopherol acetate, essentiale, legalon, flacumin) limit manifestations of indomethacin, hepatotoxicity, as a result of which tha functional-biochemical disorders in the liver show up to a lesser degree. During the combined use of antioxidants in indomethacin-induced lesions of the liver their hepatoprotective activity increases.  相似文献   
57.
To determine the potential effect of screening on referral patterns, an adult population sample (4,404 men, 5,164 women, 20-69 years of age) was systematically recruited and screened for hypercholesterolemia and then analyzed by different cholesterol referral recommendations. Using levels suggested by the Lipid Research Clinics Coronary Primary Prevention Trial (greater than or equal to 265 mg/dL), 7.3% of men and 5.8% of women would be referred for follow-up. With the suggested recommendations of the National Cholesterol Education Program (NCEP), (greater than or equal to 200 mg/dL), 49.2% of men and 40.2% of women would be referred. The use of age-related definitions of the NIH Consensus Conference on Lipid Lowering results in 28.0% referrals in men and 21.8% in women. From this population, hypercholesterolemia subjects (greater than or equal to 265 mg/dL at screening; n = 624) were invited for a second cholesterol determination (58% returned), which found 36% below the 265 mg/dL level. Population screening for cholesterol is likely to produce large numbers of patients for follow-up, with the actual numbers strongly dependent on cutoff levels and age-sex distributions. Referral and follow-up of these patients may place a significant load on an unprepared health care community.  相似文献   
58.
59.
60.
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