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   3016098篇
  免费   213679篇
  国内免费   8317篇
耳鼻咽喉   40623篇
儿科学   99738篇
妇产科学   82712篇
基础医学   430834篇
口腔科学   82852篇
临床医学   274773篇
内科学   591513篇
皮肤病学   72165篇
神经病学   243106篇
特种医学   115116篇
外国民族医学   801篇
外科学   449023篇
综合类   60886篇
现状与发展   6篇
一般理论   1090篇
预防医学   229334篇
眼科学   67811篇
药学   221422篇
  9篇
中国医学   6920篇
肿瘤学   167360篇
  2019年   23826篇
  2018年   33706篇
  2017年   25954篇
  2016年   30001篇
  2015年   33725篇
  2014年   46231篇
  2013年   69423篇
  2012年   92037篇
  2011年   97195篇
  2010年   58503篇
  2009年   56015篇
  2008年   90775篇
  2007年   96542篇
  2006年   98216篇
  2005年   93867篇
  2004年   90584篇
  2003年   87310篇
  2002年   84405篇
  2001年   146956篇
  2000年   150389篇
  1999年   126414篇
  1998年   35934篇
  1997年   31783篇
  1996年   32074篇
  1995年   31008篇
  1994年   28478篇
  1993年   26615篇
  1992年   98055篇
  1991年   94863篇
  1990年   91895篇
  1989年   89163篇
  1988年   81509篇
  1987年   79779篇
  1986年   74806篇
  1985年   71227篇
  1984年   52986篇
  1983年   44888篇
  1982年   26306篇
  1981年   23477篇
  1979年   46723篇
  1978年   32992篇
  1977年   28048篇
  1976年   26111篇
  1975年   27906篇
  1974年   32901篇
  1973年   31243篇
  1972年   29307篇
  1971年   27176篇
  1970年   25350篇
  1969年   24097篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
991.
A new technology is developed for the production of activated charcoal (AU-L) tablets from cotton lignin, a readily available local raw plant material. The physicochemical and technological properties of the parent substance (powder) have been studied and the optimum composition of tablets has been determined. The best technological characteristics of both the initial mass and the ready-to-use tablets are achieved for the composition involving a 3% methyl cellulose gel as a binding component and microcrystalline cellulose as a filler. The qualitative characteristics of AU-L tablets have been studied and their sorption capacity has been determined. The new technology will be implemented at the Tashkent Pharmaceutical Plant (Uzfarmprom Company). __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 5, pp. 49–52, May, 2007.  相似文献   
992.
The amount of protein bound per 1 mL of the perfluorocarbon (PFC) emulsion depends on the emulsifier composition and the particle size. A relationship between the amount of bound protein on the particle surface and the physicochemical parameters of the PFC emulsion interaction with the blood serum, which indirectly characterize the surface properties of the PFC particles, is established. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 12, pp. 40–43, December, 2007.  相似文献   
993.
PURPOSE: The purpose of this study was to test the functional and histologic fate of costochondral grafts (CG) in temporomandibular joint (TMJ) reconstruction for unilateral ankylosis in the sheep. MATERIALS AND METHODS: Five pure-bred adult Merino sheep were used. Ankylosis was induced by articular damage, disc removal, and placement of a bone graft. At 3 months, a gap arthroplasty was performed with a CG from the thirteenth rib. The sheep were sacrificed 3 months after CG reconstruction. The range of jaw movements were recorded at first operation, at lysis of ankylosis, and at sacrifice. The joints were examined radiologically, macroscopically, and histologically. RESULTS: All sheep showed a decrease in masticatory function, as shown by weight loss and decreased jaw opening, during the ankylosis period. On release, they regained weight and increased the range of jaw movement. Histologically, the joint space was filled with fibrous tissue. However, the partial spaces around the CG head were covered by fibrous tissue and/or fibrous cartilage. CONCLUSIONS: This study shows that, when CGs are used with a gap arthroplasty in a fibrous and bony ankylosed TMJ, masticatory function is restored.  相似文献   
994.
995.
Meningitis     
The most frequent pathogens causing bacterial meningitis in Germany are Neisseria meningitidis, Streptococcus pneumoniae, Borrelia burgdorferi, Listeria monocytogenes and staphylococci. Since immunization against Haemophilus influenzae has become a routine vaccination procedure, this pathogen no longer plays a significant role in the etiology of bacterial meningitis. A number of pilot studies have indicated that selected PCR methods most probably represent the future etiological diagnosis of bacterial meningitis. The easiest and most rapid diagnostic method is, however, still a simple gram stain preparation. In fatal cases that ran a peracute course, especially in the Waterhouse-Friderichsen syndrome, only increased congestion of the surface of the brain is detectable at autopsy. In such cases, there is hardly any histological evidence of an inflammatory reaction of the leptomeninges. In cases of purulent meningitis, in addition to the typical infiltration of the subarachnoid space with abundant granulocytes, after some days of illness there is a wide-spread histomorphological picture of pathological alterations with fibrinoid vessel wall necroses, thromboses, ventriculitis, infarctions as well as venous and arterial vasculitis. The breakdown of the integrity of the blood-brain-barrier in bacterial meningitis is obviously due to a separation of intercellular tight junctions of the endothelium of the capillaries of the leptomeninges. The cause of death in meningitis, depending on the severity and duration of a concomitant sepsis, is an increase in intracranial pressure that leads to a circulus vitiosus (via a reduced central perfusion associated with metabolic acidosis) with cerebral vasodilatation. This is followed by an additional rise of intracranial pressure and finally a reduced cerebral blood supply and central dysregulation. The medico-legal expert is occasionally confronted with this topic against the background of a possible misjudgement of the disease due to insufficient diagnostics or delayed diagnosis and in the light of a posttraumatic or nosocomial origin of the illness.  相似文献   
996.
997.
Phenytoin-induced gingival overgrowth is a recognized side effect in many cerebral palsy patients using diphenyl hydantoin for the control of seizures. Severe gingival overgrowth in these patients can affect normal masticatory function, lead to poor occlusal development, and compromise esthetics. This report addresses the complex nature of treating phenytoin-induced gingival overgrowth in a mentally retarded 20-year-old female patient. For this patient, full-mouth gingivectomy procedure was performed under general anesthesia in a single session. Post operative follow-up was uneventful. This article discusses major indications, contraindications, and protocols to be followed for periodontal surgical procedures done under general anesthesia.  相似文献   
998.
999.
Experience in the treatment of 129 patients with esophagogastric hemorrhage due to portal hypertension is discussed. An original modification of the design of Blakemore's tube is suggested, with the use of which the results of nonoperative treatment were improved and the mortality among this category of patients was reduced. Operation was performed on 75 patients. The total mortality among all hospitalized patients was 6.2%. The Tanner-Petrov operation was carried out on 55 patients, splenorenal anastomosis was formed in 6, organopexy was conducted on 4, splenectomy in combination with organopexy in 8, and portocaval anastomosis was formed in 2 patients. Three patients died after the operation.  相似文献   
1000.
Cognitive functions were investigated in 37 patients with myotonic dystrophy (MD) and correlated with clinical and neuroradiological variables. The whole cognitive performance was at a low-average level; in about 1/3 of the subjects, in fact, the scores at the neuropsychological tests were below the normal range. There was a consistent trend for patients with inheritance on maternal side to perform worse on Wechsler verbal score and to present cerebral atrophy. In 7 out of 12 subjects focal white matter lesions were found at nuclear magnetic resonance. The significance of these findings and its relation to cognitive performance are discussed.  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