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   22135篇
  免费   411篇
  国内免费   37篇
耳鼻咽喉   689篇
儿科学   467篇
妇产科学   2030篇
基础医学   3111篇
口腔科学   974篇
临床医学   702篇
内科学   3449篇
皮肤病学   749篇
神经病学   2021篇
特种医学   296篇
外科学   2251篇
综合类   70篇
一般理论   1篇
预防医学   1494篇
眼科学   1050篇
药学   2685篇
中国医学   27篇
肿瘤学   517篇
  2019年   178篇
  2018年   390篇
  2017年   265篇
  2016年   283篇
  2015年   323篇
  2014年   495篇
  2013年   664篇
  2012年   855篇
  2011年   971篇
  2010年   488篇
  2009年   231篇
  2008年   587篇
  2007年   774篇
  2006年   882篇
  2005年   805篇
  2004年   898篇
  2003年   884篇
  2002年   742篇
  2001年   669篇
  2000年   662篇
  1999年   545篇
  1998年   146篇
  1992年   363篇
  1991年   309篇
  1990年   346篇
  1989年   394篇
  1988年   453篇
  1987年   438篇
  1986年   441篇
  1985年   420篇
  1984年   336篇
  1983年   250篇
  1982年   104篇
  1981年   94篇
  1980年   96篇
  1979年   515篇
  1978年   308篇
  1977年   249篇
  1976年   242篇
  1975年   333篇
  1974年   503篇
  1973年   504篇
  1972年   421篇
  1971年   396篇
  1970年   383篇
  1969年   406篇
  1968年   351篇
  1967年   267篇
  1966年   290篇
  1965年   175篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
41.
Microbial transformation of selected azacarbazoles, compounds noted for their activity as antitumor agents, conducted with Kitasatosporia setae strain resulted in N-methylation of pyridine nucleus of alpha-, beta- and gamma-carboline molecule. Formed quaternized intermediates were converted in alkaline conditions into corresponding iso-carbolines. The structure of the final products, alpha-, beta- and gamma-iso-carbolines have been established on the basis of spectral data and confirmed by chemical synthesis.  相似文献   
42.
The paper presents the possibilities of applying the posterior thigh flap in the treatment of ischial pressure sores. Between 2000 and 2004 the flap was used in three cases treated in the Orthopaedics and Traumatology Department of the Medical Universtity in Bialystok. The indications, contraindications, operative technique and advantages of the posterior thigh flap are described. In all three cases the ischial bed sores healed well without recurrences. The posterior fasciocutaneous pedicled flap is a good method of treatment for not too extensive bed sores in the ischial region.This flap can be applied in recurrences found after primary bed sore treatment with another method. However the fasciocutaneous flap has a limited range of transposition as compared with cutaneous flaps.  相似文献   
43.
In reaction of alpha-phenyl, alpha-p-chlorophenyl and alpha-m-chlorophenylsuccinic acid with various aminopyridines, N-pyridyl-substituted succinimides (compounds 1-14) were obtained. These compounds were investigated for their CNS activity. Compounds 1, 2, 5, 6 and 7 displayed anticonvulsant properties in the maximum electroshock test. Compounds 5 and 6 were also active in the pentetrazole test.  相似文献   
44.
45.
In 10 children with acute lymphoblastic leukaemia (mean leucocyte count 452 x 10(9)/l) 17 exchange transfusions were done for rapid reduction of this count. The control group comprised 11 children with similar values of white blood cell counts (mean 324 x 10(9)/l) treated initially with small, increasing doses of corticosteroids. In contrast to acute myeloid leukaemia the results do not support the usefulness of exchange transfusions in children with hyperleukocytosis during ALL.  相似文献   
46.
Esters of N,N-diethylaminoacetic acid and hydroxyamines, obtained from structurally different natural monoterpenes, were pharmacologically examined. It was proved that salts of the obtained compounds had local anesthetic properties in infiltration anesthesia, compounds 9, 6 and 8 having been more potent than lidocaine. Compounds 7-9 slightly increased the arrhythmogenic dose, and compound 12 - the lethal dose of strophanthin. All the examined compounds transiently decreased the arterial blood pressure and displayed a cardiopressive activity.  相似文献   
47.
The authors' aim was to evaluate the range of uroflowmetry in diagnostics of stress urinary incontinence (sui) in women. The examinations were carried out in 59 women with sui, aged from 35 to 45 years (group I). The control group consisted of 20 asymptomatic women (group II). To evaluate volumes of urine voided during micturition in a unit of time a urological flowmeter UF-1 (produced by COTM, Bia?ystok) was used. Numeric data of flow were analysed, as well as registered curves of flow were ascribed to one of the following flow patterns: normal, multi-peak or interrupted. The conducted studies revealed statistically significant differences in flow values in group I, compared to group II. A more frequent incidence of multi-peak and interrupted flow patterns was found in women with sui, which could be related to a neurogenic component in etiology of the disease.  相似文献   
48.
Sympathetic skin response in scleroderma.   总被引:1,自引:0,他引:1  
Examination of the sympathetic skin response (SSR) was performed in 32 patients with systemic sclerosis, morphea and mixed connective tissue disease displaying scleroderma-like features. The control group consisted of 26 healthy subjects and 12 patients with other skin diseases and asymmetrical cutaneous changes. Right and left median and tibial nerves were stimulated successively and the responses were recorded from the palms and soles simultaneously. SSR abnormalities (delayed latency, decrease and/or asymmetry of amplitude, absent response) were observed in 68.8% of the patients, most frequently in linear scleroderma. An amplitude asymmetry of the responses from upper extremities was the most characteristic pattern of abnormalities. There was no correlation between the SSR and the localization, degree and character (inclurated oedema, atrophy, sclerosis) of skin changes, the duration of the disease, symptoms of the disorder of the autonomic nervous system symptoms (vasomotor and/or sudomotor) and the changes in capillaroscopy. All patients with slow motor conduction and sensor conduction velocities (MCV and SCV) had lower SSR amplitude and the patients with prolonged skin sensory chronaxy had more often delayed latency. The results revealed presence of disturbances of the autonomic nervous system in all varieties of scleroderma, both systemic and localized forms, even without any other signs of autonomic dysfunction.  相似文献   
49.
Experimental and clinical tests proved that cultured, autologous chondrocytes retain their properties and have ability to reconstruct hyaline-like cartilage, which represents chemical composition and biomechanical characteristics similar to normal hyaline cartilage. The aim of this part of the study was microscopic evaluation of repair tissue structural integrity and surface regularity after autologous chondrocyte transplantation. MATERIAL AND METHODS: Repair of partial thickness cartilage defect (ICRS III(o) grade) on distal femur joint surface was evaluated (25 adolescent rabbits). Procedures were performed in two groups: I--autologous chondrocyte transplantation under periosteal flap, II--periosteal graft. Chondrocytes were isolated from the cartilage specimens by enzymatic digestion and cultured in vitro. The follow-up periods were established at 4, 8, 12 weeks. Repair tissue was evaluated microscopically according to modified O'Driscoll scale. RESULTS: In group I, 4 weeks after the procedure surface of the reconstructed tissue was irregular. 8- and 12-week observation found the surface regular and plain, and repair tissue exhibited complete structural integrity. In group II, in all follow-up periods regenerate surface was irregular, there was many fissures and cracks in graft tissue, and in several cases--regenerate disintegration. CONCLUSION: Obtained results indicate, that hyaline-like cartilage reconstructed after autologous chondrocyte transplantation was characterized by regular, plain surface and complete structural integrity.  相似文献   
50.
Presented are the results of examination of 75 men, workers of the Chemical Works in Police, in whom in the scheme of complex clinical examinations detailed ophthalmological examinations have been carried out. The period of a professional contact with fluor amounted 6-15 years. The examined persons showed a variety of changes; the most important were opacities of the lens capsule, attenuation of the retinal arteries and a pathological record of the ERG.  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