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   530381篇
  免费   27658篇
  国内免费   498篇
耳鼻咽喉   6707篇
儿科学   16932篇
妇产科学   12562篇
基础医学   92674篇
口腔科学   12366篇
临床医学   48531篇
内科学   95521篇
皮肤病学   11871篇
神经病学   34042篇
特种医学   19771篇
外国民族医学   53篇
外科学   78089篇
综合类   7610篇
现状与发展   2篇
一般理论   107篇
预防医学   38555篇
眼科学   11940篇
药学   41427篇
  1篇
中国医学   1126篇
肿瘤学   28650篇
  2021年   3902篇
  2018年   5737篇
  2017年   4133篇
  2016年   4879篇
  2015年   5363篇
  2014年   7122篇
  2013年   10517篇
  2012年   15583篇
  2011年   17405篇
  2010年   9966篇
  2009年   8831篇
  2008年   15726篇
  2007年   17457篇
  2006年   16958篇
  2005年   16278篇
  2004年   15894篇
  2003年   15277篇
  2002年   14811篇
  2001年   22453篇
  2000年   22994篇
  1999年   18929篇
  1998年   5239篇
  1997年   4366篇
  1996年   4399篇
  1995年   4126篇
  1992年   14420篇
  1991年   15821篇
  1990年   15953篇
  1989年   15632篇
  1988年   14315篇
  1987年   14199篇
  1986年   13170篇
  1985年   12691篇
  1984年   9398篇
  1983年   8006篇
  1982年   4177篇
  1979年   8939篇
  1978年   6384篇
  1977年   5149篇
  1976年   5505篇
  1975年   6614篇
  1974年   7419篇
  1973年   7159篇
  1972年   6598篇
  1971年   6310篇
  1970年   5890篇
  1969年   5470篇
  1968年   5164篇
  1967年   4629篇
  1966年   3977篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
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   
72.
73.
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   
74.
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   
75.
76.
77.
78.
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   
79.
80.
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