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   60571篇
  免费   3037篇
  国内免费   327篇
耳鼻咽喉   514篇
儿科学   1224篇
妇产科学   857篇
基础医学   7921篇
口腔科学   1364篇
临床医学   3894篇
内科学   15318篇
皮肤病学   1146篇
神经病学   4451篇
特种医学   2258篇
外科学   10986篇
综合类   284篇
预防医学   1779篇
眼科学   1000篇
药学   4163篇
中国医学   164篇
肿瘤学   6612篇
  2023年   316篇
  2022年   624篇
  2021年   1107篇
  2020年   641篇
  2019年   848篇
  2018年   1135篇
  2017年   871篇
  2016年   1038篇
  2015年   1141篇
  2014年   1550篇
  2013年   1788篇
  2012年   2910篇
  2011年   3178篇
  2010年   1791篇
  2009年   1529篇
  2008年   2826篇
  2007年   3082篇
  2006年   3043篇
  2005年   3211篇
  2004年   3289篇
  2003年   3218篇
  2002年   3108篇
  2001年   1937篇
  2000年   1832篇
  1999年   1841篇
  1998年   914篇
  1997年   732篇
  1996年   670篇
  1995年   584篇
  1994年   555篇
  1993年   496篇
  1992年   1144篇
  1991年   1065篇
  1990年   934篇
  1989年   1001篇
  1988年   882篇
  1987年   793篇
  1986年   835篇
  1985年   764篇
  1984年   530篇
  1983年   444篇
  1982年   255篇
  1981年   255篇
  1980年   202篇
  1979年   361篇
  1978年   288篇
  1977年   255篇
  1975年   240篇
  1974年   210篇
  1973年   196篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
Principle for video-assisted thoracic surgery.   总被引:2,自引:0,他引:2  
  相似文献   
72.
To establish a unified classification system for mandibular osteomyelitis, various diagnostic terms were critically assessed and clinicopathologic findings of the lesions were carefully reviewed. We recommend classifying mandibular osteomyelitis into bacterial osteomyelitis and osteomyelitis associated with the synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. Other diagnostic terms were excluded because they were not appropriate for classification. Diagnostic criteria for bacterial osteomyelitis are suppuration and osteolytic change. The lesions are easily cured by antibiotic treatments. Mandibular osteomyelitis in SAPHO syndrome is characterized by nonsuppuration and a mixed pattern on radiography, with solid type periosteal reaction, external bone resorption, and bone enlargement. The presence of osteomyelitis in other bones, arthritis, or skin diseases (palmoplantar pustulosis, pustular psoriasis, and acne) strongly suggests this syndrome. Antibiotic therapy is usually ineffective and the symptoms of SAPHO syndrome are often persistent.  相似文献   
73.
Antibodies to brain proteins in paraneoplastic cerebellar degeneration   总被引:2,自引:0,他引:2  
A 68-year-old man had subacute cerebellar degeneration and a non-Hodgkin's lymphoma. Using an immunoblotting method, we found serum antibodies to rat cerebral 250-kd and 110-kd and cerebellar 110-kd acidic cytoplasmic proteins. The antibodies did not react unless the antigens were prepared soon after death with protease inhibitors. Two hundred fifty-kd and 110-kd proteins are minor components of soluble cytoplasmic proteins of the brain. The molecular weights differed from other soluble brain-specific proteins already characterized.  相似文献   
74.
75.
Electrical stimulation of several brain sites produces profound analgesia in humans, and inhibits nocifensor reflexes in animal studies. Responses of the dorsal horn nociceptive neurons evoked by stimulation onto the receptive fields are also inhibited by brain stimulation. These brain sites are Periaqueductal Gray Matter (PAG), Nucleus Raphe Magnus (NRM), Nucleus Reticularis magnocellularis (NRmc), Locus Coeruleus (LC), Lateral Hypothalamus, and others. We have explained in a general way the mechanism of these stimulation produced analgesia. The mechanism of PAG stimulation analgesia is partly due to an activation of serotonin containing neurons which descend from NRM to the spinal dorsal horn and activated by PAG stimulation. Activation of NRM neurons may produce inhibition of the nociceptive neurons of the dorsal horn by the mechanism of direct postsynaptic inhibition. Currently there is no evidence to support the theory of presynaptic inhibition. Endogenous opioid peptides do not play an important role in PAG stimulation analgesia. On the other hand, the mechanism of NRmc or LC stimulation analgesia may be due to an activation of noradrenaline containing neurons which similarly inhibit the dorsal horn nociceptive neurons in the spinal cord. At present, it still remains unknown whether endogenous opioid peptides play an important role in this type of analgesia.  相似文献   
76.
A case of an odontogenic tumor which invaded the intracranial space from the mandible is reported. Judging from the radiographic images it was similar to a malignant tumor. The patient died 17 years after the first visit. According to the final pathological diagnosis, it was malignant odontogenic mixed tumor of low grade which did not belong to any of the WHO classification.  相似文献   
77.
This report concerns the long-term outcome of living donor liver transplantation (LDLT) for pediatric patients at a single center. Between June 1990 and December 2003, a total of 600 LDLTs, including 568 primary transplantations and 32 retransplantations, were performed for pediatric patients, who were immunosuppressed with FK506 and low-dose corticosteroids. Patient survival at 1, 5, and 10 years were 84.6%, 82.4%, and 77.2%, respectively, and the corresponding findings for graft survivals were 84.1%, 80.9%, and 74.5%. Multivariate analysis demonstrated that fulminant hepatic failure (FHF), a graft vs. body weight (GBWR) ratio of <0.8, and ABO-incompatible transplants were independently associated with both patient and graft survival. The retransplantation rate was 6%, and 55 patients (9.7%) have been completely weaned off immunosuppressants. Long-term patient and graft survival after pediatric LDLT for a large cohort of children at our hospital were found to be as good as those for cadaveric liver transplantation, although this series includes 13% liver transplantations with ABO-incompatible donors, which are obviously inferior in patient and graft survival. To obtain better outcomes for patients with FHF and for patients with ABO-incompatible transplants, immunosuppressive therapy needs to be improved.  相似文献   
78.
Neoplastic angioendotheliosis has rarely been described as a respiratory disease. A patient is described with pulmonary vascular involvement induced by neoplastic angioendotheliosis in pulmonary vessels.  相似文献   
79.
The case of a 75-year-old man with three synchronous carcinomas of the lung (large cell carcinoma, adenocarcinoma, and small cell carcinoma) is reported. This is the eighth well-documented case report in the literature; however, our case is the first to be reported with the newly described histological combination.  相似文献   
80.
We present herein the rare case of a young man who was found to have a solitary tumor in the right upper lobe of his lung by a routine chest X-ray. The tumor was removed by thoracoscopic surgery, and pathological examinations confirmed the diagnosis of a primary lymphangioma of the lung. A brief review of the available literature on this extremely rare type of benign tumor follows the case report.  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