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   675624篇
  免费   34870篇
  国内免费   685篇
耳鼻咽喉   8960篇
儿科学   21753篇
妇产科学   15849篇
基础医学   114716篇
口腔科学   16906篇
临床医学   60598篇
内科学   121740篇
皮肤病学   16285篇
神经病学   48928篇
特种医学   26426篇
外国民族医学   53篇
外科学   99916篇
综合类   8282篇
现状与发展   2篇
一般理论   148篇
预防医学   46269篇
眼科学   14998篇
药学   51782篇
  1篇
中国医学   1346篇
肿瘤学   36221篇
  2021年   5261篇
  2019年   5449篇
  2018年   8739篇
  2017年   6741篇
  2016年   8242篇
  2015年   8384篇
  2014年   10503篇
  2013年   16281篇
  2012年   23004篇
  2011年   25809篇
  2010年   14834篇
  2009年   12258篇
  2008年   24288篇
  2007年   26472篇
  2006年   25659篇
  2005年   24860篇
  2004年   24048篇
  2003年   23544篇
  2002年   22899篇
  2001年   27493篇
  2000年   29314篇
  1999年   22563篇
  1998年   6902篇
  1997年   5714篇
  1996年   5494篇
  1995年   5049篇
  1992年   15184篇
  1991年   16481篇
  1990年   16585篇
  1989年   16274篇
  1988年   14877篇
  1987年   14820篇
  1986年   13681篇
  1985年   13406篇
  1984年   10105篇
  1983年   8608篇
  1982年   4829篇
  1979年   9447篇
  1978年   6868篇
  1977年   5666篇
  1976年   5944篇
  1975年   7058篇
  1974年   7843篇
  1973年   7518篇
  1972年   6888篇
  1971年   6630篇
  1970年   6179篇
  1969年   5723篇
  1968年   5426篇
  1967年   4878篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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   
62.
63.
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   
64.
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   
65.
66.
67.
68.
The in vitro activities of povidone iodine, potassium peroxymonosulfate, and dimethyldidecylammonium chloride were investigated against 379 nosocomial isolates of Staphylococcus aureus and Pseudomonas aeruginosa responsible for surgical wound infections in patients operated on between July 1995 and June 2001. Overall, the isolates were inhibited by the antiseptics at concentrations below those used routinely. In spite of increasing resistance to the various antibiotics used to treat surgical wound infections, no significant variation in the susceptibility to antiseptics was demonstrated during this 6-year study. Electronic Publication  相似文献   
69.
70.
Deep venous thrombosis and pulmonary embolism   总被引:2,自引:0,他引:2  
All surgical patients are at risk for the development of deep venous thrombosis and subsequent pulmonary embolism or postphlebitic syndrome. The evolution of ultrasonographic imaging has increased the awareness of prevention, diagnosis, and treatment of deep venous thrombosis. Duplex imaging and Doppler color flow imaging have made the diagnosis of deep venous thrombosis relatively simple, painless, inexpensive, and definitive. These procedures have gained acceptance by both patients and physicians. Several risk factors have been identified that increase the chance of the development of deep venous thrombosis. These factors include a history of deep venous thrombosis, presence of a malignant process, increasing age, cigarette smoking, obesity, prolonged bed rest, and general anesthesia. The greater the number of risk factors, the more aggressive prophylaxis should be. Means of prophylaxis have improved, and surgeons now generally agree that some form of prophylaxis is required. Heparin and intermittent compression devices appear to be equally effective in preventing deep venous thrombosis. The addition of venous monitoring in high-risk patients permits immediate identification of the presence of deep venous thrombosis. During the last decade, the treatment of patients with deep venous thrombosis has changed little. Heparin followed by warfarin remains the treatment of choice. A small group of patients receive fibrinolytic therapy for deep venous thrombosis. Although the incidence of postoperative deep venous thrombosis has decreased during the last decade, it remains a significant complication.  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