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   1603192篇
  免费   131571篇
  国内免费   2585篇
耳鼻咽喉   21663篇
儿科学   53085篇
妇产科学   46247篇
基础医学   227888篇
口腔科学   47245篇
临床医学   140991篇
内科学   315082篇
皮肤病学   34118篇
神经病学   130180篇
特种医学   64840篇
外国民族医学   474篇
外科学   243895篇
综合类   39761篇
现状与发展   3篇
一般理论   545篇
预防医学   122906篇
眼科学   36520篇
药学   121514篇
  3篇
中国医学   2979篇
肿瘤学   87409篇
  2018年   14787篇
  2016年   12920篇
  2015年   15046篇
  2014年   20701篇
  2013年   31397篇
  2012年   42614篇
  2011年   44821篇
  2010年   26371篇
  2009年   25345篇
  2008年   43055篇
  2007年   45291篇
  2006年   46093篇
  2005年   44722篇
  2004年   44139篇
  2003年   42225篇
  2002年   41326篇
  2001年   75712篇
  2000年   78347篇
  1999年   66419篇
  1998年   17750篇
  1997年   16355篇
  1996年   16334篇
  1995年   16032篇
  1994年   15081篇
  1993年   14224篇
  1992年   55460篇
  1991年   53813篇
  1990年   52587篇
  1989年   50866篇
  1988年   47257篇
  1987年   46585篇
  1986年   44309篇
  1985年   42870篇
  1984年   32063篇
  1983年   27603篇
  1982年   16166篇
  1981年   14453篇
  1980年   13581篇
  1979年   30483篇
  1978年   21086篇
  1977年   17778篇
  1976年   16707篇
  1975年   17582篇
  1974年   21504篇
  1973年   20690篇
  1972年   18873篇
  1971年   17786篇
  1970年   16304篇
  1969年   15288篇
  1968年   13964篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
993.
We report histological changes in four patients with port wine stains treated with 578 nm yellow light from a high power copper vapour laser. Histology showed that selective damage occurred to the ectatic blood-vessels in the dermis, without haemorrhage and damage to non-vascular structures, and without scarring. The initial damage to the overlying epidermis was not permanent, and the damaged ectatic vessels returned to normal size or were completely necrosed and replaced by collagen.  相似文献   
994.
The present status of total colectomy with ileorectal anastomosis in the surgical treatment of inflammatory bowel disease is examined. Special reference is made to the different indications for the use of the operation in Crohn's disease and in ulcerative colitis. The late results are illustrated by the outcome in the 59 patients in a personal series, and other published results.  相似文献   
995.
Synovectomy of the knee in patients with hemophilia presenting in countries with demographic characteristics that make central referral difficult is the subject of this article. Ten patients, six surgeons, and two countries contributed to this study, which demonstrated that approximately 40% of these patients had no further hemarthroses into the affected joint and the remainder had reduced frequency and severity of bleeding. Continuous passive motion has an important place in postoperative management, and manipulation with the patient under anesthesia is of doubtful value. The possible relationship between diminished range of movement and a successful outcome in terms of abolition of hemorrhage is explored. One patient underwent synovectomy of the knee without complication; the other nine suffered significant complications.  相似文献   
996.
Indirect evidence suggests that amphetamine (AMPH) releases dopamine (DA) from an extravesicular, cytoplasmic pool. Disruption of vesicular DA storage by reserpine has been hypothesized to increase the concentration of extravesicular DA available for release by AMPH, which is consistent with the observation that reserpine does not prevent but augments the behavioral response to AMPH. In order to more directly test this hypothesis, the in vivo microdialysis technique was used to concurrently examine the behavioral and striatal dopaminergic response to AMPH (1.25 or 2.5 mg/kg) 24 h following reserpine pretreatment (2.5 mg/kg). Reserpine decreased tissue levels of DA by approximately 90% and reduced baseline dialysate DA concentrations by approximately 80%. Reserpine augmented the behavioural effects of AMPH, particularly increasing the occurrence and intensity of stereotypies. In contrast, reserpine did not alter the amount or duration of AMPH-induced DA release. This observation confirms that DA release by AMPH does not depend on vesicular stores but is inconsistent with the hypothesis that augmentation or behaviour by reserpine results from increased striatal DA release.  相似文献   
997.
The results of this controlled study of the treatment of 57 patients with Gilles de la Tourette's syndrome suggested that both haloperidol and pimozide were more effective than placebo, but that haloperidol was slightly more effective than pimozide. Adverse effects occurred more frequently with haloperidol vs placebo than with pimozide vs placebo, but the frequency was not significantly different for haloperidol compared with pimozide. Clinically significant cardiac effects did not occur at a maximum dosage of 0.3 mg/kg or 20 mg/d for pimozide and 10 mg/d for haloperidol. However, the QTc interval was prolonged during pimozide treatment compared with that during haloperidol treatment, although the values for both medications were not in an abnormal range.  相似文献   
998.
To date, chronic myopathy has not been reported (to our knowledge) to occur in carnitine palmityltransferase (CPT) deficiency, a disorder of muscle lipid metabolism. We describe two patients with CPT deficiency: a mother, who had a partial CPT deficiency associated with fixed proximal weakness but without rhabdomyolysis, and her son, who had a complete CPT deficiency (95% reduction in enzyme activity) and who suffered from classic attacks of exercise-induced rhabdomyolysis but had normal strength on recovery. Careful examination of family members of patients with complete CPT deficiency is suggested in order to identify clinically affected heterozygotes.  相似文献   
999.
Paracoccidioidomycosis of the central nervous system presents either as meningeal or pseudotumoral lesions. Although occurring more frequently in the brain and meninges, they can occasionally involve the spinal cord. A case of paracoccidioidomycosis in the cervical spinal cord is reported in this paper. Difficulties in establishing the etiologic diagnosis, the importance of radiologic examination of the thorax, and the treatment of the patient are commented. In an extensive review of the literature on the subject, only three other cases have been found, which are also discussed.  相似文献   
1000.
The effect of apomorphine on regional cerebral blood flow in schizophrenia   总被引:1,自引:0,他引:1  
A double-blind, placebo-controlled crossover study of the effects of apomorphine on regional cerebral blood flow (rCBF) during a prefrontal cortex activation task was undertaken to explore the role of dopamine on cortical function. The subjects were eight drug-free, chronically psychotic patients; six patients had schizophrenia. In each, apomorphine increased the relative prefrontal flow. The results suggest that enhanced prefrontal dopamine activity may reverse deficits in prefrontal cortex metabolism in schizophrenia.  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