为探讨电子束灭菌技术应用于鱼类加工半成品的最佳剂量,采用0~8.56 k Gy辐照剂量对鲈鱼半成品进行灭菌,分析不同剂量电子束辐照对鲈鱼半成品菌落总数、p H、持水性、色度值、剪切力和挥发性成分的影响。结果表明,随辐照剂量的增加,杀菌...为探讨电子束灭菌技术应用于鱼类加工半成品的最佳剂量,采用0~8.56 k Gy辐照剂量对鲈鱼半成品进行灭菌,分析不同剂量电子束辐照对鲈鱼半成品菌落总数、p H、持水性、色度值、剪切力和挥发性成分的影响。结果表明,随辐照剂量的增加,杀菌效果增强;辐照剂量为3.70~4.41 k Gy时菌落总数即可降至≤10 CFU·g-1;辐照剂量在2.45~7.24 k Gy范围内能控制鲈鱼半成品p H的下降;辐照剂量高于8.56 k Gy时,辐照对鱼肉持水力和剪切力无显著影响;辐照剂量低于6.64 k Gy时,对鲈鱼半成品色泽的影响较小;与6.64 k Gy相比,低剂量(3.33 k Gy)辐照处理有利于减少烷类、烯类挥发性成分的产生。综上所述,电子束辐照剂量在4.00 k Gy左右时,可达到灭菌目的,并有效控制鱼肉色度、p H和持水性,最大限度地保持产品原有风味和品质。展开更多
目的:比较《国际功能、残疾和健康分类》(儿童和青少年版)(international classification of functioning,disability and health:children and youth version,ICF-CY)框架指导下的以案例为基础学习(Case-based Learning,CBL)教学方法+...目的:比较《国际功能、残疾和健康分类》(儿童和青少年版)(international classification of functioning,disability and health:children and youth version,ICF-CY)框架指导下的以案例为基础学习(Case-based Learning,CBL)教学方法+以问题为基础学习(Problem-Based Learning,PBL)的教学方法与传统的讲授式教学方法(Lecture-Based Learning,LBL)在儿童康复科临床实习教学中的应用效果。方法:将实习同学随机分为实验组和对照组,分别按照计划进行教学,实习结束进行闭卷考试进行教学效果比较,同时结合问卷调查了解学生对新教学模式的适应性。结果:实验组理论成绩及操作成绩结果明显优于对照组,实验组对新教学模式呈现良好的适应性,有利于学生对儿童康复专科知识的掌握。结论:在儿童康复科临床实习中运用ICF-CY下CBL+PBL方法进行教学,有利于提高学生的主动意识及对理论知识和临床操作的掌握。展开更多
Two Klebsiella pneumoniae isolates （Kpcl and Kpc2） were obtained from liver samples of seven dead chickens and identified with Vitek-32 automated identification system. Antimicrobial susceptibilities were determined...Two Klebsiella pneumoniae isolates （Kpcl and Kpc2） were obtained from liver samples of seven dead chickens and identified with Vitek-32 automated identification system. Antimicrobial susceptibilities were determined by the microdilution broth method. Detection of genes encoding class A β-lactamases was performed by PCR amplification, and cloning of the ESBL gene was by plasmid restriction and fragments ligation. Conjugation assay, transformation experiments and plasmid profile analysis were performed. The incompatibility group of ESBL-carrying plasmid was determined by the PCR-based replicon typing method. Lastly, the genetic environment was analysed by direct sequencing of the DNA surrounding the ESBL gene. The genes associated with tetracycline and gentamicin resistance were also sought by PCR. The results revealed that the ESBL phenotype-negative strain Kpc2 only showed resistance to ampicillin, amoxicillin, tetracycline, and doxycycline and carried bla TEM-1 and tet（A） genes. The ESBL-producing strain Kpcl exhibited multidrug resistant phenotype and harbored bla TEM-1 , bla CTX-M-14, tet（A）, tet（B）, and rmtB genes. K. pneumoniae Kpcl contained four plasmids with molecular sizes of approximately 59, 6.9, 2.8, and 1.6 kb, but only a 59-kb plasmid, carried bla TEM-1 and blac CTM-14 genes, was observed in its transconjugant. The incompatibility group of plasmid carrying blaCTX-M-14 gene could not be determined. The bla CTX-M-14 gene was flanked upstream by an ISEcpl insertion sequence and downstream by an IS903 element. This work shows that CTX-M-14 is present in K. pneumoniae isolates from chickens in China. The bla CTX -M-4 gene was associated with an upstream ISEcpl insertion sequence. Our results underline the need for continuous surveillance of the prevalence and evolution of this CTX-M-type β-lactamase in China.展开更多
文摘研究居住建筑采用不同保温墙体的节能效果,介绍混凝土夹心保温墙体构造,运用理论计算满足节能的最小保温厚度及其热工参数.以严寒地区某居住建筑为研究对象,通过DeST能耗模拟软件建立模型,分别研究挤塑聚苯板、岩棉、聚氨酯和真空绝热板夹心保温材料在不同厚度下对建筑能耗的影响,利用全生命周期法分析其经济性,Matlab曲线拟合净现值确定保温材料最优厚度.结果表明,4种保温材料相同厚度下保温隔热性能依次是真空绝热板、聚氨酯、挤塑聚苯板、岩棉,其对应最优厚度分别为20、50、75和90 mm.
文摘为探讨电子束灭菌技术应用于鱼类加工半成品的最佳剂量,采用0~8.56 k Gy辐照剂量对鲈鱼半成品进行灭菌,分析不同剂量电子束辐照对鲈鱼半成品菌落总数、p H、持水性、色度值、剪切力和挥发性成分的影响。结果表明,随辐照剂量的增加,杀菌效果增强;辐照剂量为3.70~4.41 k Gy时菌落总数即可降至≤10 CFU·g-1;辐照剂量在2.45~7.24 k Gy范围内能控制鲈鱼半成品p H的下降;辐照剂量高于8.56 k Gy时,辐照对鱼肉持水力和剪切力无显著影响;辐照剂量低于6.64 k Gy时,对鲈鱼半成品色泽的影响较小;与6.64 k Gy相比,低剂量(3.33 k Gy)辐照处理有利于减少烷类、烯类挥发性成分的产生。综上所述,电子束辐照剂量在4.00 k Gy左右时,可达到灭菌目的,并有效控制鱼肉色度、p H和持水性,最大限度地保持产品原有风味和品质。
文摘目的:比较《国际功能、残疾和健康分类》(儿童和青少年版)(international classification of functioning,disability and health:children and youth version,ICF-CY)框架指导下的以案例为基础学习(Case-based Learning,CBL)教学方法+以问题为基础学习(Problem-Based Learning,PBL)的教学方法与传统的讲授式教学方法(Lecture-Based Learning,LBL)在儿童康复科临床实习教学中的应用效果。方法:将实习同学随机分为实验组和对照组,分别按照计划进行教学,实习结束进行闭卷考试进行教学效果比较,同时结合问卷调查了解学生对新教学模式的适应性。结果:实验组理论成绩及操作成绩结果明显优于对照组,实验组对新教学模式呈现良好的适应性,有利于学生对儿童康复专科知识的掌握。结论:在儿童康复科临床实习中运用ICF-CY下CBL+PBL方法进行教学,有利于提高学生的主动意识及对理论知识和临床操作的掌握。
基金funded by the National Natural Science Foundation of China (31072170)
文摘Two Klebsiella pneumoniae isolates （Kpcl and Kpc2） were obtained from liver samples of seven dead chickens and identified with Vitek-32 automated identification system. Antimicrobial susceptibilities were determined by the microdilution broth method. Detection of genes encoding class A β-lactamases was performed by PCR amplification, and cloning of the ESBL gene was by plasmid restriction and fragments ligation. Conjugation assay, transformation experiments and plasmid profile analysis were performed. The incompatibility group of ESBL-carrying plasmid was determined by the PCR-based replicon typing method. Lastly, the genetic environment was analysed by direct sequencing of the DNA surrounding the ESBL gene. The genes associated with tetracycline and gentamicin resistance were also sought by PCR. The results revealed that the ESBL phenotype-negative strain Kpc2 only showed resistance to ampicillin, amoxicillin, tetracycline, and doxycycline and carried bla TEM-1 and tet（A） genes. The ESBL-producing strain Kpcl exhibited multidrug resistant phenotype and harbored bla TEM-1 , bla CTX-M-14, tet（A）, tet（B）, and rmtB genes. K. pneumoniae Kpcl contained four plasmids with molecular sizes of approximately 59, 6.9, 2.8, and 1.6 kb, but only a 59-kb plasmid, carried bla TEM-1 and blac CTM-14 genes, was observed in its transconjugant. The incompatibility group of plasmid carrying blaCTX-M-14 gene could not be determined. The bla CTX-M-14 gene was flanked upstream by an ISEcpl insertion sequence and downstream by an IS903 element. This work shows that CTX-M-14 is present in K. pneumoniae isolates from chickens in China. The bla CTX -M-4 gene was associated with an upstream ISEcpl insertion sequence. Our results underline the need for continuous surveillance of the prevalence and evolution of this CTX-M-type β-lactamase in China.
