为研究高剂量率对牛血清辐照灭菌中的活性下降的抑制作用,将新生牛血清分别经平均剂量率为60、600 Gy/min钴源和300 k Gy/min电子加速器3种方式辐照30 k Gy后,分析牛血清蛋白的生化特性和结构变化及其与剂量率的关系。结果表明,与未辐...为研究高剂量率对牛血清辐照灭菌中的活性下降的抑制作用,将新生牛血清分别经平均剂量率为60、600 Gy/min钴源和300 k Gy/min电子加速器3种方式辐照30 k Gy后,分析牛血清蛋白的生化特性和结构变化及其与剂量率的关系。结果表明,与未辐照牛血清相比,辐照后蛋白浊度、疏水氨基酸荧光强度、放热峰出峰时间分别从0.742、24.1 u和16.5 min升高至0.802、99.3 u和17.2 min,而蛋白浓度、放热峰温度分别从0.473和76.4℃下降至0.444和74.5℃。电泳分析(SDS-PAGE)显示,600 Gy/min钴源辐照牛血清中相对分子质量为175 k Da和58 k Da的蛋白组分含量明显大于低剂量率辐照牛血清。经扫描电镜(SEM)分析,辐照后牛血清中沉淀部分呈现密集的网络结构,未沉淀部分呈现碎片和球状体混合的形貌结构,低剂量率辐照的样品蛋白球状体形貌不突出。可见高剂量率有抑制辐照灭菌牛血清蛋白分子变性的作用,3种方式中600 Gy/min钴源效果最明显。展开更多
Alginate were hydrophobically modified by coupling of heptylamine onto it.The composition and structure of the product were characterized by IR and 1HNMR.The result of fluorescence analysis showed that S-0 and S-3 for...Alginate were hydrophobically modified by coupling of heptylamine onto it.The composition and structure of the product were characterized by IR and 1HNMR.The result of fluorescence analysis showed that S-0 and S-3 formed self-aggregates in 0.15mol/L aqueous NaCl solution and their critical aggregation concentration were 0.7g/L and 1.1g/L respectively.The new heptylamine-alginate conjugate was used for immobilization of BSA in the presence of calcium chloride.In addition,the encapsulation rate and the release behavior in deionized water and Tris-Hcl buffer solution(pH7.2) were investigated.Comparing to unmodified alginate,the modified sodium alginate has relative higher encapsulation rate and prolonger release behavior.展开更多
文摘为研究高剂量率对牛血清辐照灭菌中的活性下降的抑制作用,将新生牛血清分别经平均剂量率为60、600 Gy/min钴源和300 k Gy/min电子加速器3种方式辐照30 k Gy后,分析牛血清蛋白的生化特性和结构变化及其与剂量率的关系。结果表明,与未辐照牛血清相比,辐照后蛋白浊度、疏水氨基酸荧光强度、放热峰出峰时间分别从0.742、24.1 u和16.5 min升高至0.802、99.3 u和17.2 min,而蛋白浓度、放热峰温度分别从0.473和76.4℃下降至0.444和74.5℃。电泳分析(SDS-PAGE)显示,600 Gy/min钴源辐照牛血清中相对分子质量为175 k Da和58 k Da的蛋白组分含量明显大于低剂量率辐照牛血清。经扫描电镜(SEM)分析,辐照后牛血清中沉淀部分呈现密集的网络结构,未沉淀部分呈现碎片和球状体混合的形貌结构,低剂量率辐照的样品蛋白球状体形貌不突出。可见高剂量率有抑制辐照灭菌牛血清蛋白分子变性的作用,3种方式中600 Gy/min钴源效果最明显。
文摘Alginate were hydrophobically modified by coupling of heptylamine onto it.The composition and structure of the product were characterized by IR and 1HNMR.The result of fluorescence analysis showed that S-0 and S-3 formed self-aggregates in 0.15mol/L aqueous NaCl solution and their critical aggregation concentration were 0.7g/L and 1.1g/L respectively.The new heptylamine-alginate conjugate was used for immobilization of BSA in the presence of calcium chloride.In addition,the encapsulation rate and the release behavior in deionized water and Tris-Hcl buffer solution(pH7.2) were investigated.Comparing to unmodified alginate,the modified sodium alginate has relative higher encapsulation rate and prolonger release behavior.
