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   1566篇
  免费   97篇
耳鼻咽喉   17篇
儿科学   28篇
妇产科学   22篇
基础医学   191篇
口腔科学   203篇
临床医学   144篇
内科学   336篇
皮肤病学   25篇
神经病学   144篇
特种医学   49篇
外科学   155篇
综合类   7篇
预防医学   173篇
眼科学   30篇
药学   120篇
中国医学   4篇
肿瘤学   15篇
  2023年   7篇
  2022年   11篇
  2021年   31篇
  2020年   24篇
  2019年   28篇
  2018年   44篇
  2017年   46篇
  2016年   52篇
  2015年   53篇
  2014年   51篇
  2013年   78篇
  2012年   120篇
  2011年   136篇
  2010年   50篇
  2009年   43篇
  2008年   92篇
  2007年   94篇
  2006年   105篇
  2005年   92篇
  2004年   70篇
  2003年   59篇
  2002年   62篇
  2001年   36篇
  2000年   40篇
  1999年   23篇
  1998年   11篇
  1997年   8篇
  1996年   6篇
  1995年   5篇
  1992年   14篇
  1991年   23篇
  1990年   10篇
  1989年   5篇
  1988年   8篇
  1987年   7篇
  1986年   8篇
  1985年   10篇
  1984年   7篇
  1980年   4篇
  1979年   11篇
  1978年   9篇
  1976年   4篇
  1975年   4篇
  1974年   3篇
  1972年   4篇
  1971年   4篇
  1970年   11篇
  1969年   4篇
  1968年   6篇
  1967年   6篇
排序方式: 共有1663条查询结果,搜索用时 15 毫秒
101.
Friedreich's ataxia is commonly associated with depression. Treatment of the depression can be difficult due to numerous morbid medical conditions. ECT is a safe and effective treatment option.  相似文献   
102.
Basal cell adenoma is a benign epithelial neoplasm with a uniform histologic appearance dominated by basaloid cells. Those cells may be distributed in various arrangements as solid, trabecular, tubular and membranous. Canalicular adenoma is also a benign neoplasm composed by columnar cells arranged in branching and interconnecting cords of single or double cell thick rows. There is some disagreement among investigators about whether canalicular adenoma should be included within the basal cell adenoma histologic spectrum. In the present study we compared the expression of cytokeratins (CK), vimentin and muscle-specific actin, utilizing immunohistochemical technique, in three cases diagnosed as basal cell adenomas predominantly of the solid type, and three cases of canalicular adenomas. The results obtained showed a distinct immunoprofile for both neoplasms. Solid areas of basal cell adenomas did not stain for any of the tested antibodies; only when there was tubular differentiation, those structures expressed CKs 7, 8, 14, and 19 in luminal cells and vimentin in non-luminal cells. On the other hand, canalicular adenomas strongly expressed CKs 7 and 13. The panel of antibodies utilized supports the separation of the two entities.  相似文献   
103.
This study describes the antinociceptive activity of some N-aryl-glutaramic acids and N-aryl-glutarimides in writhing and formalin tests, two classical models of pain in mice. These compounds show high activity, being more active than acetyl salycilic acid, acetaminophen and indomethacin, used as standard drugs for comparison. The introduction of different substituent groups in the aromatic ring caused a significant change in activity. The results obtained here are promising from a pharmacological point of view, since these simple compounds might be used as models to obtain new and potent analgesic drugs.  相似文献   
104.
Eleven chalcones were prepared and tested as antinociceptive agents using the writhing test in mice. Some compounds, given intraperitoneally, caused potent and dose-related antinociception, being several times more active than some reference drugs. The results evidenced that some physico-chemical parameters are involved in the pharmacological activity. 3,4-Dichlorochalcone (2) was the most effective compound, and was also studied in another model of pain in mice, the formalin test. Here it inhibited only the inflammatory pain (second phase), being equipotent to the reference drugs.  相似文献   
105.
Computerized mapping of atrial fibrillation was performed in animals and man. To study atrial fibrillation in a systematic manner, we developed a clinically relevant experimental model of atrial fibrillation. Chronic mitral regurgitation was created surgically in 25 dogs without opening the pericardium. After several months of chronic mitral regurgitation, the atria became enlarged and sustained atrial fibrillation could be induced by standard programmed electrical stimulation techniques. Computerized isochronous activation maps of the atria were recorded during atrial fibrillation from 208 bipolar electrodes simultaneously. In a parallel study, human atrial fibrillation was mapped with a separate 160-channel intraoperative mapping system in patients with paroxysmal atrial fibrillation who were undergoing surgical correction of the Wolff-Parkinson-White syndrome. The canine activation sequence maps demonstrated a spectrum of rhythm abnormalities ranging from simple atrial flutter to complex atrial fibrillation. They also showed that macroreentrant circuits within the atrial myocardium were responsible for the entire spectrum of arrhythmias. Atrial reentry was also documented during human atrial fibrillation. All patients had nonuniform conduction around regions of bidirectional block in both atria resulting in multiple discrete wave fronts. In addition, six patients had a single reentrant circuit in the right atrium in which bidirectional block of the activation wave front occurred along the sulcus terminals between the venae cavae. The left atrium in all patients demonstrated multiple wave fronts and conduction block, but left atrial reentry could not be detected. Both the experimental study and the clinical study demonstrated that multiple wave fronts, nonuniform conduction, bidirectional block, and large (macroreentrant) reentrant circuits occur during atrial fibrillation. The presence of macroreentrant circuits and the absence of either microreentrant circuits or evidence of atrial automaticity suggests that atrial fibrillation should be amenable to surgical ablation.  相似文献   
106.
Fournier''s gangrene of scrotum in a patient with AIDS.   总被引:4,自引:2,他引:2       下载免费PDF全文
Fournier's gangrene of the scrotum, a form of necrotising fasciitis, is a rare but potentially fatal disorder. Predisposing conditions include chronic alcoholism and diabetes mellitus, possibly as a result of impaired immunity. Fournier's syndrome, occurring in a patient with AIDS, is described.  相似文献   
107.
Calvarial haemangiomas are rare benign tumours that may be suspected by their characteristic expansile ‘sunburst’ appearance. It is important to recognize them as such and to make the surgeon aware of haemorrhage after biopsy or resection.  相似文献   
108.
109.
The objective of this study was to obtain a better characterization of Dirofilaria immitis (Leidy, 1856) Railliet & Henry, 1911, in Brazil, ratifying previous accounts and adding new data on the rugose area on the ventral surface of the spiralled posterior portion of males observed by scanning electron microscopy, which presents a different arrangement compared to other species of the genus, and differs also from the genera Litomosoides Chandler, 1931, and Wuchereria Silva Araújo, 1877, adding another taxonomic character to Dirofilariinae and Onchocercinae. Scanning electron microscopy studies also showed some aspects of the distribution of caudal papillae in D. immitis that have not been described before. Received: 4 April 1999 / Accepted: 23 April 1999  相似文献   
110.
The frequency of neurological manifestations was evaluated in 653 HIV infected patients admitted in a university hospital in Rio de Janeiro city, Brazil, in the 1985-1989 period. A total of 172 (26%) patients developed neurological symptoms. Central nervous system complications included: cerebral toxoplasmosis (80), cryptococcal meningitis (57), subacute encephalitis (17), tuberculosis (8) and aseptic meningitis (2), progressive multifocal leukoencephalopathy (2) and vacuolar myelopathy (6). Peripheral neuropathy occurred in three cases. The clinical and tomographic aspects were analysed. The majority of the patients died within six months after the onset of the neurological disease.  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