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   435篇
  免费   16篇
  国内免费   2篇
耳鼻咽喉   16篇
儿科学   17篇
妇产科学   4篇
基础医学   55篇
口腔科学   3篇
临床医学   11篇
内科学   96篇
皮肤病学   3篇
神经病学   35篇
特种医学   28篇
外科学   107篇
综合类   6篇
预防医学   12篇
眼科学   1篇
药学   11篇
肿瘤学   48篇
  2023年   4篇
  2022年   2篇
  2021年   4篇
  2020年   9篇
  2019年   16篇
  2018年   5篇
  2017年   4篇
  2016年   10篇
  2015年   6篇
  2014年   3篇
  2013年   7篇
  2012年   15篇
  2011年   23篇
  2010年   14篇
  2009年   7篇
  2008年   16篇
  2007年   18篇
  2006年   22篇
  2005年   26篇
  2004年   12篇
  2003年   21篇
  2002年   21篇
  2001年   15篇
  2000年   22篇
  1999年   13篇
  1998年   10篇
  1997年   6篇
  1996年   14篇
  1995年   11篇
  1994年   5篇
  1993年   1篇
  1992年   12篇
  1991年   13篇
  1990年   11篇
  1989年   10篇
  1988年   8篇
  1987年   9篇
  1986年   13篇
  1985年   7篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1959年   1篇
排序方式: 共有453条查询结果,搜索用时 31 毫秒
1.
2.
Incidence of cervical cancer is high among Bolivian Andean women. Human papillomavirus (HPV) infection is known as the major risk factor of cervical cancer. The host immune system plays an important role in the outcome of HPV infection and associated malignancies. In order to study the immunogenetic background of Bolivian Andean women with regard to HPV infection status, we compared HLA class I and class II allele frequencies between 37 HPV positive and 68 HPV negative Bolivian women. Demographic variables, including distribution of Andean ethnicities, were similar in both groups. Comparison of HLA class I allele frequencies between both groups indicated no significant difference. In contrast, HLA class II DRB1*1602 allele, an Amerindian allele, was significantly higher in the HPV positive women compared with HPV negative controls (chi(2) = 5.2, p < 0.05, odds ratio = 3.17; 95% confidence interval = 1.4-8.8). HPV types present in the HPV positive group were HPV-18, -16, -31, -33, and -58. These results suggest that HLA class II DRB1*1602 may confer susceptibility to infection with genetically related HPV types. This is the first report of an HLA class II association with HPV infection in an Andean population.  相似文献   
3.
4.
BACKGROUND: Antihistamines have been evaluated for usefulness in the treatment of asthma for more than 50 years. Interest was limited until the introduction of newer compounds that were free of much of the dose-limiting sedation associated with the earlier drugs. OBJECTIVE: In a murine model of allergen-induced airway inflammation and hyperresponsiveness, the efficacy of an H1 receptor antagonist to prevent allergic inflammation and altered airway function was evaluated. METHODS: Mice were sensitized and challenged to an allergen, ovalbumin, which elicited marked airway and tissue eosino-philia and airway hyperresponsiveness. Fexofenadine was administered before challenge, and airway responsiveness to inhaled methacholine, airway and tissue eosinophilia, bronchoalveolar lavage fluid cytokine levels, and serum IgE levels were assayed. In a second group of experiments, sensitized and challenged mice were treated or not treated with fexofenadine before challenge. T cells were isolated from the lungs and adoptively transferred into naive recipients before exposure to limited airway allergen challenge, and lung function and inflammation were evaluated. RESULTS: Fexofenadine treatment of sensitized mice prevented the development of airway hyperresponsiveness in both the primary sensitization and challenge, as well as in the adoptive transfer experiments. These changes were accompanied by decreases in bronchoalveolar lavage and tissue eosinophilia, lymphocyte numbers, and T(H)2 cytokine production. CONCLUSION: The results demonstrate the efficacy of an H1 receptor antagonist in preventing allergen-induced alterations in pulmonary inflammation and airway function. The data support the evaluation of drugs such as fexofenadine in the treatment of allergic asthma.  相似文献   
5.
PURPOSE: The aim of this study was to determine the usefulness of MR cholangiopancreatography (MRCP) of intraductal papillary-mucinous tumors. METHOD: Thirteen patients with intraductal papillary-mucinous tumors were examined by breath-hold MRCP using a half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence with a body phased-array coil. RESULTS: Endoscopic retrograde cholangiopancreatography (ERCP) and MRCP completely imaged the entire main pancreatic duct in 12 and in all 13 patients, respectively. ERCP demonstrated the whole opacification of the cystic lesion in only one patient. MRCP depicted the whole of the cystic lesion in all 11 patients who had cystic lesions. ERCP and MRCP source images depicted a communicating duct between the main pancreatic duct and the cystic lesion in 8 and in all 11 patients, respectively. ERCP depicted papillary projections in the main pancreatic ducts in two patients. MRCP source images depicted papillary projections in the main pancreatic ducts or cystic lesions in five patients. CONCLUSION: MRCP may be more useful to reveal the main pancreatic duct, cystic lesion, communicating duct between the main pancreatic duct and cystic lesion, and papillary projections than ERCP in patients with intraductal papillary-mucinous tumors of the pancreas.  相似文献   
6.
7.
8.
Strictureplasty for short duodenal stenosis in Crohn's disease   总被引:2,自引:0,他引:2  
Involvement of the gastroduodenum is extremely rare in Crohn's disease. For obstructing duodenal Crohn's disease, bypass procedures have traditionally been selected. However, more recently, strictureplasty has become an acceptable surgical option. We treated two Crohn's disease patients with short proximal duodenal stenosis, using Finney-type strictureplasty. Their postoperative courses were uneventful and they have remained asymptomatic during follow-up periods of more than 5 years, and 4 months, respectively. Owing to the good clinical results of our two patients, we consider strictureplasty to be indicated for short proximal duodenal stenosis in Crohn's disease. Received: October 14, 1999 / Accepted: February 25, 2000  相似文献   
9.
Abstract

To clarify the topographical relationship between peri-Rolandic lesions and the central sulcus, we carried out presurgical functional mapping by using magnetoencephalography (MEG), functional magnetic resonance imaging (f-MRI), and motor evoked potentials (MEPs) on 5 patients. The sensory cortex was identified by somatosensory evoked magnetic fields using MEG (magnetic source imaging (MSI)). The motor area of the hand region was identified using f-MRI, during a hand squeezing task. In addition, transcranial magnetic stimulation localized the hand motor area on the scalp, which was mapped onto the MRI. In all cases, the sensory cortical vein or the lack of any functional activation in the area of peri-lesional edema. MEPs were also unable to localize the entire motor strip. Therefore, at present, MSI is considered to be the most reliable method to localize peri-Rolandic lesions. [Neurol Res 1995; 17: 361-367] cortical vein or the lack of any functional activation in the area of peri-lesional edema. MEPs were also unable to localize the entire motor strip. Therefore, at present, MSI is considered to be the most reliable method to localize peri-Rolandic lesions. [Neurol Res 1995; 17: 361-367]  相似文献   
10.
The taiep rat is a myelin mutant in which immobility episodes (IEs) can be induced in adult males by gripping. EEG recordings during gripping-induced IEs show a rapid eye movement (REM) sleep-like pattern, similar to that reported for narcolepsy-cataplexy suggesting that IEs represent a disorder of REM-sleep. An alpha(2) adrenoceptor agonist increases gripping-induced IEs, whereas alpha(2) antagonists decrease these. We have studied the effect of prazosin on IEs and the levels of alpha(1) adrenoceptors were evaluated in cerebro-cortical homogenates of taiep and control rats. Systemic administration of prazosin results in a significant increase in both the frequency and duration of gripping-induced IEs. Our results show that cerebro-cortical tissue is not an adequate candidate for the expression of cataplexy-like symptoms, but prazosin, an alpha(1) antagonist, is a potent inducer of gripping-induced immobility episodes in taiep rats.  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