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   216篇
  免费   6篇
耳鼻咽喉   6篇
儿科学   1篇
妇产科学   6篇
基础医学   38篇
口腔科学   11篇
临床医学   12篇
内科学   49篇
皮肤病学   1篇
神经病学   10篇
特种医学   2篇
外科学   24篇
预防医学   15篇
眼科学   8篇
药学   31篇
中国医学   1篇
肿瘤学   7篇
  2023年   1篇
  2022年   3篇
  2021年   8篇
  2020年   10篇
  2019年   5篇
  2018年   4篇
  2017年   2篇
  2016年   5篇
  2015年   3篇
  2014年   6篇
  2013年   9篇
  2012年   13篇
  2011年   19篇
  2010年   4篇
  2009年   5篇
  2008年   7篇
  2007年   20篇
  2006年   14篇
  2005年   15篇
  2004年   8篇
  2003年   10篇
  2002年   10篇
  2001年   5篇
  2000年   5篇
  1999年   2篇
  1998年   1篇
  1997年   2篇
  1996年   2篇
  1995年   6篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   3篇
  1986年   4篇
  1985年   4篇
  1980年   1篇
  1978年   1篇
  1976年   1篇
排序方式: 共有222条查询结果,搜索用时 46 毫秒
1.
The AA. refer on the first Italian case of amoebae "Limax" primitive myelitis in a 25-year-old man. Microscopical observation showed amoebae free-living, but their cultivation and identification were not possible. The patient recovered because of the propriety of diagnosis and therapy with amphotericin B.  相似文献   
2.
Summary The ionic composition of the internal environment was altered in rabbits by means of gastric washing, combined with intramuscular administration of 3-Beta-aminoethylpyrazole. The effects of this treatment on cortical spreading depression (SD) were studied. C1- and Na+ concentrations decreased significantly in serum and in cerebrospinal fluid after the treatment. This made the animals much more susceptible to SD, as established by the high incidence of spontaneous SD, increased SD velocity of propagation and facilitated its interhemispheric transfer. An intensification of the epileptiform activity associated with SD was also observed. Intravenous replacement of NaCl abolished the above effects on SD. When the intravenous replacement was done with Na-Isethionate, those effects were enhanced. It is concluded that chloride deficiency was the main factor responsible for the observed facilitating effects.This work was supported by grants from the BNDE (FUNTEC-74 e 143), CNPq and CAPES  相似文献   
3.
Transcriptional block of HTLV-I LTR by sequence-specific methylation   总被引:2,自引:0,他引:2  
  相似文献   
4.
The diarrhetic shellfish toxin composition in the hepatopancreas of mussels from the northern Adriatic sea was investigated. The major toxins were shown to be yessotoxin (YTX), homoyessotoxin (homoYTX) and 45-hydroxyyessotoxin (45-OHYTX), identified by comparison of their chromatographic and spectral properties with those reported in the literature.  相似文献   
5.
6.
Kelly RF  Tran T  Holmstrom A  Murar J  Segurola RJ 《Chest》2004,125(4):1413-1423
STUDY OBJECTIVES: This retrospective study of patients who were referred for surgical resection of non-small cell lung cancer (NSCLC) assessed the accuracy and cost-effectiveness of positron emission tomography (PET) with radiolabeled [18F]-2-fluoro-deoxy-D-glucose (FDG) in staging mediastinal lymph nodes (MLNs). DESIGN: From January 2001 to September 2002, 90 patients with suspected or proven NSCLC who had been referred for curative resection were retrospectively reviewed. All patients were without evidence of metastatic disease. Sixty-nine of the 90 patients had undergone thoracic FDG-PET imaging as part of their evaluation and are the focus of this study. Sensitivity, specificity, accuracy, and positive and negative predictive values for metastasis to the MLN were calculated for CT scanning vs FDG-PET scanning. Four algorithms for staging MLN with mediastinoscopy and/or FDG-PET scan were compared. MEASUREMENTS AND RESULTS: Sixty-nine patients underwent preoperative CT and FDG-PET scans, and 32 of 69 patients underwent mediastinoscopy. Fifty-seven patients underwent thoracotomy with complete mediastinal lymphadenectomy. Sensitivity, specificity, accuracy, and positive and negative predictive values for CT scans and FDG-PET scans were 46%, 86%, 78%, 43%, and 87%, and 62%, 98%, 91%, 89% and 92%, respectively. Mediastinoscopy was accurate in 32 of 32 patients (100%). Routine mediastinoscopy remains the most economically reasonable strategy with excellent sensitivity. Selective FDG-PET imaging improved the sensitivity of noninvasive staging for patients with normal MLNs on CT scans. CONCLUSIONS: Selective use of FDG-PET imaging improves staging accuracy compared to CT scanning alone and makes it a cost-effective adjunct to the preoperative staging of NSCLC. However, in patients with adenocarcinoma and MLNs of < 1 cm, FDG-PET scanning cannot yet replace mediastinoscopy.  相似文献   
7.
Cardiopulmonary exercise testing (CPET) provides a global assessment of the integrated response to exercise involving the pulmonary, cardiovascular, haematopoietic, neuropsychological, and skeletal muscle systems. This information cannot be obtained through investigation of the individual organ systems in isolation. The non-invasive, dynamic physiological overview permits the evaluation of both submaximal and peak exercise responses, providing the physician with relevant information for clinical decision making. The use of CPET in management of the chronic heart failure patient is increasing with the understanding that resting pulmonary and cardiac function testing cannot reliably predict exercise performance and functional capacity and that, furthermore, overall health status and prognosis are predicted better by indices of exercise tolerance than by resting measurements. Our aim is to produce a statement which provides recommendations on the interpretation and clinical application of CPET in heart failure, based on contemporary scientific knowledge and technical advances: the focus is on clinical indications, issues of standardization, and interpretative strategies for CPET.  相似文献   
8.
BACKGROUND: The objective of this study was to determine the effects of a moderate exercise training program on functional capacity, quality of life, and hospital readmission rate in chronic heart failure patients with implantable cardioverter defibrillators and cardiac resynchronization therapy. METHODS AND RESULTS: We studied 52 men (mean age 55+/-10 years, ejection fraction 31+/-7%) in chronic heart failure II (n=29) and III (n=23) NYHA functional class with ischemic cardiomyopathy who received implantable cardioverter defibrillators with or without cardiac resynchronization therapy. Patients were randomized into two groups. Group T (n=30 patients, 15 implantable cardioverter defibrillator, 15 implantable cardioverter defibrillator+cardiac resynchronization therapy) underwent a supervised exercise training program at 60% of peak VO2 three times a week for 8 weeks. Group C (n=22 patients, 12 implantable cardioverter defibrillator, 10 implantable cardioverter defibrillator+cardiac resynchronization therapy) avoided physical training. At 8 weeks, only trained patients had improvements in peak VO2 (P<0.01 versus C), endothelium-dependent dilatation of the brachial artery (P<0.001 versus C) and quality of life (P<0.001 versus C). Among trained patients, those with cardiac resynchronization therapy had greater improvements in peak VO2 and quality of life. During the follow-up (24+/-6 months), eight controls had sustained ventricular tachycardia requiring hospital readmission, while no trained patients had adverse events (log rank 8.56; P<0.001). The improvement in peak VO2 was correlated with the improvement in endothelium-dependent dilatation (r=0.65). CONCLUSION: Moderate exercise training is safe and has beneficial effects after implantable cardioverter defibrillator implantation, especially when cardiac resynchronization therapy is present. These effects are associated with improvement in quality of life and outcome.  相似文献   
9.
New ceramic formulations based on scheelite tailing were developed, and their potential in the ceramic industry was evaluated. Green bodies with different contents of scheelite tailing (0–8 wt%) were sintered (1150 °C, 1200 °C, and 1250 °C) and characterized in terms of the main mineralogical phases, microstructure, and physico-mechanical properties. The mullite was the main phase identified in all sintered temperatures. This result was also ratified with the aid of scanning electron microscope (SEM) images, in which small needles of the mullite were detected. The presence of mullite is required because it contributes to increasing the mechanical resistance of the material. The physico-mechanical properties measured (water absorption, linear shrinkage, apparent porosity, and flexural strength) were compared to the ISO 13006, and the samples sintered at 1150 °C presented potential to be used as semi-stoneware, while those sintered at 1200 °C and 1250 °C can be employed stoneware and porcelain tiles, respectively.  相似文献   
10.
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