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   889篇
  免费   48篇
  国内免费   6篇
耳鼻咽喉   5篇
儿科学   41篇
妇产科学   3篇
基础医学   146篇
口腔科学   8篇
临床医学   57篇
内科学   208篇
皮肤病学   19篇
神经病学   155篇
特种医学   49篇
外科学   134篇
综合类   3篇
预防医学   8篇
眼科学   15篇
药学   28篇
中国医学   2篇
肿瘤学   62篇
  2022年   9篇
  2021年   9篇
  2020年   9篇
  2019年   7篇
  2018年   15篇
  2017年   14篇
  2016年   10篇
  2015年   19篇
  2014年   33篇
  2013年   33篇
  2012年   49篇
  2011年   47篇
  2010年   23篇
  2009年   16篇
  2008年   38篇
  2007年   44篇
  2006年   50篇
  2005年   48篇
  2004年   56篇
  2003年   50篇
  2002年   53篇
  2001年   27篇
  2000年   11篇
  1999年   31篇
  1998年   17篇
  1997年   13篇
  1996年   10篇
  1995年   8篇
  1994年   13篇
  1993年   11篇
  1992年   20篇
  1991年   16篇
  1990年   10篇
  1989年   17篇
  1988年   9篇
  1987年   12篇
  1986年   9篇
  1985年   5篇
  1984年   7篇
  1983年   3篇
  1982年   6篇
  1981年   6篇
  1980年   6篇
  1979年   9篇
  1978年   4篇
  1976年   4篇
  1975年   8篇
  1969年   2篇
  1968年   4篇
  1967年   2篇
排序方式: 共有943条查询结果,搜索用时 15 毫秒
101.
Discrimination between aspergilloma and chronic necrotizing pulmonary aspergillosis (CNPA) based on radiological findings can difficult. We describe a patient with aspergilloma and organizing pneumonia that was possibly caused by Aspergillus niger infection and radiologically mimicked CNPA. A postmortem histological analysis showed diffuse alveolar damage that had originated in peri-cavitary lung parenchyma. Calcium oxalate or Aspergillus niger was located inside, but not outside the cavity in the right upper lobe. Calcium oxalate or other unknown hyphal bioactive components might provoke severe lung inflammation not only adjacent to the cavity, but also on the contralateral side.KEY WORDS : Calcium oxalate crystal deposition, aspergilloma, black deposits, Aspergillus niger  相似文献   
102.
Summary The measurement of neuron-specific enolase level in serum and cerebrospinal fluid was conducted time-sequentially in an autopsy confirmed patient with Creutzfeld-Jakob disease. The level was markedly high in the early stage of the disease at which time the brain CT showed no or minimal abnormalities, while falling into the normal range in the advanced stage. This is the first report of the elevated level of neuron-specific enolase in Creutzfeldt-Jakob disease.Abbreviations CT Computed tomography - CSF Cerebrospinal fluid - CJD Creutzfeldt-Jakob disease - NSE Neuronspecific enolase - CEA Carcinoembryonic antigen - PSD Periodic synchronous discharge - PET Positron emission tomography  相似文献   
103.
104.
BACKGROUND: We previously reported that puromycin aminonucleoside (PAN) increased adrenomedullin (AM) secretion and AM mRNA expression in podocytes, through overproduction of oxidative stress. To clarify the cytoprotective role of AM as antioxidative and antiapoptotic substance in podocytes, we investigated the effect of exogenous AM and AM antagonist on PAN-induced apoptosis in conditionally immortalized murine podocytes. METHODS: The expression of AM, RAMP 2 and RAMP 3 was investigated using real-time PCR, western blotting analysis and immunofluorescence microscopy. Reactive oxygen species (ROS) production was measured by CM-H(2)DCFDA fluorescence intensity method. The percentage of apoptotic cells was measured by Hoechst 33342 staining. RESULTS: PAN (100 microg/ml) significantly (P < 0.01) increased ROS production, associated with an increase in apoptosis; the percentage of apoptotic cells is 5.3% + 0.05% (P < 0.01) with 36 h treatment of PAN compared to 0.24 + 0.16% with no treatment. Several antioxidants could markedly reduce PAN-induced apoptosis in cultured podocytes, suggesting that PAN-induced apoptosis might be attributable to the overproduction of ROS. Accordingly, the administration of exogenous AM (10(-6) M) could significantly reduce not only ROS production via a PKA-dependent pathway, but also the resultant apoptosis induced by PAN. AM antagonists, CGRP8-37, augmented PAN-induced apoptosis, associated with increased ROS production, 2.2- and 2.3-Fold, respectively. RAMP 2 and RAMP 3 could be detected in podocytes and glomeruli. CONCLUSIONS: This suggests that ROS-induced up-regulation of AM with PAN could counteract ROS-induced apoptosis, by the suppression of ROS production. Therefore, AM might have the endogenous antioxidant potential to protect against ROS-induced podocyte injury.  相似文献   
105.
106.
107.
108.
Y Wakayama  E Bonilla  D L Schotland 《Neurology》1983,33(10):1368-1370
Muscle biopsies from one preclinical case, one early case, four symptomatic cases of Duchenne muscular dystrophy, and six controls were investigated for the presence of delta lesions by phase optics and conventional electronmicroscopy. By phase microscopy the frequency of delta lesions was 4.9% in the preclinical and early cases and 4.0% in the four symptomatic cases. The incidence of delta lesions in the controls was 0.4%. Electronmicroscopic studies of delta lesions revealed similar findings in the preclinical, early, and symptomatic cases. The common denominator of the delta lesions was disruption of the muscle plasma membrane. Plasma membrane lesions occur early in Duchenne muscular dystrophy.  相似文献   
109.
This is a review of the application of cell surface cytochemistry to the study of human neuromuscular disease. The advantages and limitations of the use of lectins coupled to peroxidase are discussed, and the application of this technique is illustrated by a study of the surface of muscle cells in Duchenne muscular dystrophy and polymyositis.  相似文献   
110.
The potassium permanganate method and the unlabeled immunoperoxidase (PAP) method were applied for distinguishing different types of amyloid fibril proteins in conventionally fixed, paraffin-embedded tissue sections obtained from fifty-one autopsied cases of systemic amyloidosis and three control cases of well-analysed fibril proteins. All of the eighteen cases "sensitive" to permanganate treatment, whose amyloid deposits lost completely their affinity to Congo red and birefringence under polarized light, were shown to have AA antigenic determinants by the PAP method. Meanwhile, all of the remaining thirty-three "resistant" cases, where Congo red affinity and birefringence were retained at various degree even only in minimal areas, were negative for AA antigenicity. This indicated the feasibility of potassium permanganate method for the identification of AA protein based on this criterion of "sensitivity". Twenty-eight cases were classified as AA, Aγ, Ak or AA+[Ak] the remaining twenty-three cases were unclassified, and there were some discrepancies between the preliminary clinicopathological classification and the protein nature of the amyloid. It is important to differentiate the types of amyloid fibril protein of individual patients because the expedience of selective therapeutic approaches had been suggested. The two methods applied herein are handy and useful for this purpose.  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