全文获取类型
收费全文 | 2450529篇 |
免费 | 176302篇 |
国内免费 | 4845篇 |
专业分类
耳鼻咽喉 | 33167篇 |
儿科学 | 80112篇 |
妇产科学 | 67059篇 |
基础医学 | 349616篇 |
口腔科学 | 71147篇 |
临床医学 | 221426篇 |
内科学 | 470694篇 |
皮肤病学 | 55849篇 |
神经病学 | 190159篇 |
特种医学 | 93925篇 |
外国民族医学 | 437篇 |
外科学 | 370934篇 |
综合类 | 53879篇 |
现状与发展 | 5篇 |
一般理论 | 757篇 |
预防医学 | 179845篇 |
眼科学 | 57989篇 |
药学 | 185366篇 |
13篇 | |
中国医学 | 6195篇 |
肿瘤学 | 143102篇 |
出版年
2021年 | 18508篇 |
2019年 | 19163篇 |
2018年 | 27757篇 |
2017年 | 21307篇 |
2016年 | 23697篇 |
2015年 | 26765篇 |
2014年 | 36954篇 |
2013年 | 54061篇 |
2012年 | 74621篇 |
2011年 | 78635篇 |
2010年 | 46618篇 |
2009年 | 43529篇 |
2008年 | 72832篇 |
2007年 | 77727篇 |
2006年 | 78416篇 |
2005年 | 74920篇 |
2004年 | 72049篇 |
2003年 | 68816篇 |
2002年 | 66308篇 |
2001年 | 127996篇 |
2000年 | 131012篇 |
1999年 | 108693篇 |
1998年 | 28524篇 |
1997年 | 24943篇 |
1996年 | 25005篇 |
1995年 | 23895篇 |
1994年 | 21799篇 |
1993年 | 20373篇 |
1992年 | 82077篇 |
1991年 | 79154篇 |
1990年 | 76924篇 |
1989年 | 73831篇 |
1988年 | 67121篇 |
1987年 | 65414篇 |
1986年 | 61814篇 |
1985年 | 58576篇 |
1984年 | 42900篇 |
1983年 | 36514篇 |
1982年 | 20499篇 |
1979年 | 38186篇 |
1978年 | 26259篇 |
1977年 | 22847篇 |
1976年 | 20724篇 |
1975年 | 22537篇 |
1974年 | 26926篇 |
1973年 | 25945篇 |
1972年 | 24241篇 |
1971年 | 22620篇 |
1970年 | 20928篇 |
1969年 | 19794篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
991.
K S Bjerve L Thoresen S B?rsting 《JPEN. Journal of parenteral and enteral nutrition》1988,12(5):521-525
N-3 fatty acid deficiency is described in a 7-year-old girl who had been fed solely by gastric tube from the age of 3 years. She had received the same nutrient during the last 22 months, supplying 16.2% of calories from linoleate and 0.07% from alpha-linolenate. She weighed 9.5 kg at the age of 3, and 10.3 kg at the start of the study, the weight being constant the last 15 months. She was now supplemented daily with 1.2 ml of a linseed- and cod liver-oil mixture (5:1, v/v), thereby increasing her alpha-linolenate intake to 0.71% and total N-3 fatty acids to 0.74% of total energy. Two months later, her rate of weight gain was 0.43 kg/month. After 5 months, the fatty acid supplement was changed to 7.5 ml of cod liver oil daily, thereby changing alpha-linolenate and total N-3 acid intake to 0.10% and 1.3% of total energy, respectively. Her rate of weight gain now increased to 0.64 kg/month, and her length increased from 117 to 122 cm in 5 months. The results indicate that the optimal dietary requirement for N-3 fatty acids in this child is higher than 0.74%, and extrapolation estimated the optimal requirement to be 1.1%-1.2% of total calories. The results suggest that N-3 fatty acids are required for normal growth in man. 相似文献
992.
993.
Exposure to high pressure produces neurologic changes in humans which manifest as tremor, EEG changes, and convulsions. Since previous studies have implicated the involvement of the serotoninergic system in these symptoms, it was of interest to study serotonin release at high pressure. Synaptosomes isolated from guinea pig striatum were used to follow serotonin efflux at 68 ATA. The major observation was a decrease in [3H]serotonin release from depolarized striatal synaptosomes at 68 ATA. In view of the role of serotonin as an inhibitory neurotransmitter in this area, the observed decrease in synaptic release leads us to conclude that decreased serotoninergic activity in striatal neurons probably is contributing to the hyperexcitability associated with HPNS. 相似文献
994.
995.
996.
D Bild L S Geiss S M Teutsch B Gabella B A Hudspeth R M Schubert C W Gollmar D J Kaplan F A Connell J C Will 《Journal of clinical epidemiology》1988,41(10):999-1006
The pilot study for a sentinel health events surveillance system for deaths among persons under age 45 with diabetes was conducted in six states in 1984 and 1985. Two hundred and thirty-three events were identified. Information from death certificates, physicians, and families revealed that 22% died from acute complications of diabetes and 53% from chronic complications. Blood pressure measurement and urinalysis testing had been performed in the last year for almost all of the decedents, but other preventive practices were reported less frequently. Hypertension was present in 57% and of those, was not controlled in 73%. Forty-four percent were cigarette smokers at the time of death. Agreement between physicians and families was generally higher for clinical conditions than for care practices. This surveillance system appears to yield information about the health care of persons with diabetes not readily available from other sources, although modifications may be necessary before implementation. 相似文献
997.
SRIVASTAVA Z. I.; MATHUR N.; RASTOGI S. K.; GUPTA B. N. 《Occupational medicine (Oxford, England)》1988,38(4):134-136
Eighty-nine cases of chronic bronchitis were matched against167 asymptomatic controls from the glass bangle industry ofFirozabad. Factors of age, social status, smoking habit andduration of exposure were studied. Duration of exposure wasfound to be a factor contributing significantly to the causationof disease.
Requests for reprints should be addressed to: Dr B. N. Gupta, Division of Epidemilogy, Industrial Toxicology Research Centre, Mahatma Gandhi Marg, Lucknow P.O. Box 80, 226001, India 相似文献
998.
999.
We examined six patients with Gardner's syndrome, eight first-degree relatives, and 31 age- and sex-matched controls to document the presence, distribution, and morphologic features of congenital hypertrophy of the retinal pigment epithelium. Patients with Gardner's syndrome had multiple, bilateral lesions, with 288 of 346 foci (83%) located posterior to the equator. Linear-shaped congenital hypertrophy of the retinal pigment epithelium, a distinctive finding in these patients, accounted for 44 of 140 large lesions (31%). Despite multifocal fundus involvement, results of electro-oculography were normal in all eyes tested. 相似文献
1000.
A Watanabe K Ohizumi M Motomiya K Takeuchi T Yoshida S Ida Y Miura K Nishioka Y Tanno T Takishima 《The Japanese journal of antibiotics》1990,43(8):1392-1401
We evaluated the therapeutic efficacy of miconazole (MCZ, Florid-F inj.), a new antifungal agent for parenteral use, in deep-seated fungal infections of respiratory tract system. A daily dose of 400-1,800 mg of MCZ was given intravenously for 12-38 days (mean: 23.4 days) to 7 patients: 2 patients with pulmonary aspergillosis, 1 patient with bronchial aspergillosis, 1 patient with pulmonary candidiasis and 3 patients with candidemia. One additional patient with pulmonary aspergillosis received three instillations of 20 mg of MCZ into the thoracic cavity. The clinical effects were excellent in 1, good in 4 and poor in 3 patients. The efficacy rate was 100% in 5 cases with respiratory fungal infections but 3 cases with candidemia did not respond well to the treatment. Four strains each of Aspergillus sp. and Candida sp. were identified as causative organisms. Seven of the 8 strains were eradicated by administration of MCZ. Side effects observed were irritation and heat in a leg in 1 patient, hyperlipoidemia in 2 patients and eosinophilia in 1 patient. The adverse reactions disappeared after the completion of the therapy. From the above results, we conclude that MCZ is one of the most useful antifungal agents for parenteral use as a first choice on deep-seated fungal infections in the respiratory tract. 相似文献