Objectives:To determine the incidence of resistance of Streptococcus(Strep).pneumoniae isolated in our locality to erythromycin,to screen for the two resistance determinants erm(B) and mef(A) genes,and to identify the...Objectives:To determine the incidence of resistance of Streptococcus(Strep).pneumoniae isolated in our locality to erythromycin,to screen for the two resistance determinants erm(B) and mef(A) genes,and to identify the susceptibility profile to commonly used antibiotics.Methods:Samples were collected from patients attending the Outpatient Department of Zagazig University Hospital,Zagazig,Egypt,between February 2006 and March 2007.Strep.pneumoniae was identified by conventional procedures.Susceptibilities to erythromycin and 15 antibiotics were identified by disc diffusion method,as outlined by CLSI.E-test was used for MIC determination of erythromycin.erm(B) and mef(A) genes were detected by PCR.Results:Eighty-one Strep. pneumoniae strains were identified.Fifty- one of them(63%) were erythromycin-resistant,and mef(A) gene was the predominant resistance determinant.Vancomycin,imipenem and gatifloxacin had the best activity against the isolates,whereas tetracycline had the least.Forty-two(51.85%) out of the 81 Strep.pneumoniae strains were multidrug-resistant.Conclusions:High incidence of resistance to erythromycin and multiple antimicrobials existed.mef(A) was the principal erythromycin-resistance gene.展开更多
The desolvation of erythromycin acetone solvate was investigated under non-isothermal conditions by a thermogravimetric analyzer. This paper emphasized the kinetic analysis of non-isothermal TG-DTA data by Achar metho...The desolvation of erythromycin acetone solvate was investigated under non-isothermal conditions by a thermogravimetric analyzer. This paper emphasized the kinetic analysis of non-isothermal TG-DTA data by Achar method and Coats-Redfern method to fit various solid-state reaction models, and to achieve kinetic parameters of desolvation. The mechanism of thermal desolvation was evaluated using the kinetic compensation effect. The results show that kinetics of desolvation of erythromycin acetone solvate was compatible with the mechanism of a two-dimensional diffusion controlled and was best expressed by Valensi equation. Corresponding to the integral method and the differential method, the activation energy of desolvation of erythromycin acetone solvate was estimated to be 51.26—57.11 kJ/mol, and the pre-exponential factor was 8.077×106 s-1—4.326×107 s-1, respectively.展开更多
随着全球化进程的推进,国内经济环境变化更为快速、影响因素也更加复杂,许多公司不仅仅关注会计利润的提升,更多的关注了对于风险的管理和控制方面,本文将使用CSMAR数据库中2013-2021年我国上市公司的数据,借鉴Beasley et al.(2005)中...随着全球化进程的推进,国内经济环境变化更为快速、影响因素也更加复杂,许多公司不仅仅关注会计利润的提升,更多的关注了对于风险的管理和控制方面,本文将使用CSMAR数据库中2013-2021年我国上市公司的数据,借鉴Beasley et al.(2005)中构建评估COSO提出的全面风险管理框架,实证研究公司ERM水平与其绩效之间的影响关系。研究结果表明,在控制了公司规模、股权集中度、公司国有性质、财务杠杆率、总资产增长率等影响因素后,公司企业风险管理水平的提升对其绩效水平有显著的促进作用,实施ERM程度更高的公司的业绩表现更好。展开更多
文摘Objectives:To determine the incidence of resistance of Streptococcus(Strep).pneumoniae isolated in our locality to erythromycin,to screen for the two resistance determinants erm(B) and mef(A) genes,and to identify the susceptibility profile to commonly used antibiotics.Methods:Samples were collected from patients attending the Outpatient Department of Zagazig University Hospital,Zagazig,Egypt,between February 2006 and March 2007.Strep.pneumoniae was identified by conventional procedures.Susceptibilities to erythromycin and 15 antibiotics were identified by disc diffusion method,as outlined by CLSI.E-test was used for MIC determination of erythromycin.erm(B) and mef(A) genes were detected by PCR.Results:Eighty-one Strep. pneumoniae strains were identified.Fifty- one of them(63%) were erythromycin-resistant,and mef(A) gene was the predominant resistance determinant.Vancomycin,imipenem and gatifloxacin had the best activity against the isolates,whereas tetracycline had the least.Forty-two(51.85%) out of the 81 Strep.pneumoniae strains were multidrug-resistant.Conclusions:High incidence of resistance to erythromycin and multiple antimicrobials existed.mef(A) was the principal erythromycin-resistance gene.
文摘The desolvation of erythromycin acetone solvate was investigated under non-isothermal conditions by a thermogravimetric analyzer. This paper emphasized the kinetic analysis of non-isothermal TG-DTA data by Achar method and Coats-Redfern method to fit various solid-state reaction models, and to achieve kinetic parameters of desolvation. The mechanism of thermal desolvation was evaluated using the kinetic compensation effect. The results show that kinetics of desolvation of erythromycin acetone solvate was compatible with the mechanism of a two-dimensional diffusion controlled and was best expressed by Valensi equation. Corresponding to the integral method and the differential method, the activation energy of desolvation of erythromycin acetone solvate was estimated to be 51.26—57.11 kJ/mol, and the pre-exponential factor was 8.077×106 s-1—4.326×107 s-1, respectively.
文摘随着全球化进程的推进,国内经济环境变化更为快速、影响因素也更加复杂,许多公司不仅仅关注会计利润的提升,更多的关注了对于风险的管理和控制方面,本文将使用CSMAR数据库中2013-2021年我国上市公司的数据,借鉴Beasley et al.(2005)中构建评估COSO提出的全面风险管理框架,实证研究公司ERM水平与其绩效之间的影响关系。研究结果表明,在控制了公司规模、股权集中度、公司国有性质、财务杠杆率、总资产增长率等影响因素后,公司企业风险管理水平的提升对其绩效水平有显著的促进作用,实施ERM程度更高的公司的业绩表现更好。
