The kinetics of the reversible martensitic transformation in a Cu-Zn-Al-Mn-Ni shape memory alloy has been studied by means of differential scanning calorimetry.The apparent activation energy has been calculated and th...The kinetics of the reversible martensitic transformation in a Cu-Zn-Al-Mn-Ni shape memory alloy has been studied by means of differential scanning calorimetry.The apparent activation energy has been calculated and the kinetic equations of positive and adverse martensitic transformation have been established with the variations of temperature and time.展开更多
目的采用化学方法合成天然产物松柏醇(CA)并评价其抗炎镇痛活性。方法以阿魏酸为原料,与亚砜生成酰氯、再酯化,最后还原得到CA,其结构经红外、质谱和核磁确证。采用脂多糖(LPS)致RAW264.7细胞损伤模型评价CA的体外抗炎活性;构建小鼠足...目的采用化学方法合成天然产物松柏醇(CA)并评价其抗炎镇痛活性。方法以阿魏酸为原料,与亚砜生成酰氯、再酯化,最后还原得到CA,其结构经红外、质谱和核磁确证。采用脂多糖(LPS)致RAW264.7细胞损伤模型评价CA的体外抗炎活性;构建小鼠足肿胀炎症模型和醋酸致小鼠扭体模型分别评价CA的抗炎镇痛活性。结果本研究共合成1.1 g CA,其化学结构与已报到的结果相符合。MTT测定结果表明松柏醇(1~32μmol/L)本身对RAW264.7细胞生长无明显影响。LPS干预RAW264.7细胞后,细胞生长受到明显抑制。与LPS组相比,CA在4,8和16μmol/L时对LPS致RAW264.7细胞损伤具有保护作用。CA可剂量依赖性地降低细胞上清液中一氧化氮(NO)、前列腺素E_(2)(PGE_(2))、肿瘤坏死因子-α(TNF-α)、白介素6(IL-6)和白介素1-β(IL-1β)水平,显示出较好的抗炎作用。动物实验结果表明腹腔注射给予CA(20、40 mg/kg)能明显改善角叉菜胶致小鼠足肿胀程度,也能明显减少醋酸致小鼠扭体次数。结论CA具有良好的抗炎镇痛活性,在炎症疾病领域具有开发价值。展开更多
The atmospheric oxidation of a quenched CuZnAlMnNi alloy after ion-polishing was examined by transmission electron microscopy (TEM). It was found that a lot of oxide grains with various sizes yield homogeneously on th...The atmospheric oxidation of a quenched CuZnAlMnNi alloy after ion-polishing was examined by transmission electron microscopy (TEM). It was found that a lot of oxide grains with various sizes yield homogeneously on the surface of the alloy after exposure at room temperature for 90 d. The grains mainly form along the planes of stacking fault, meanwhile, they can also be observed at the stacking fault tetrahedrals or around the dislocation lines. The formation of the oxides gives rise to the reduction of the stacking faults, and even complete disappearance in some zones, which is partly responsible for the decrement of shape memory effect (SME) of the alloy quenched during long-term holding at room temperature.展开更多
文摘The kinetics of the reversible martensitic transformation in a Cu-Zn-Al-Mn-Ni shape memory alloy has been studied by means of differential scanning calorimetry.The apparent activation energy has been calculated and the kinetic equations of positive and adverse martensitic transformation have been established with the variations of temperature and time.
文摘目的采用化学方法合成天然产物松柏醇(CA)并评价其抗炎镇痛活性。方法以阿魏酸为原料,与亚砜生成酰氯、再酯化,最后还原得到CA,其结构经红外、质谱和核磁确证。采用脂多糖(LPS)致RAW264.7细胞损伤模型评价CA的体外抗炎活性;构建小鼠足肿胀炎症模型和醋酸致小鼠扭体模型分别评价CA的抗炎镇痛活性。结果本研究共合成1.1 g CA,其化学结构与已报到的结果相符合。MTT测定结果表明松柏醇(1~32μmol/L)本身对RAW264.7细胞生长无明显影响。LPS干预RAW264.7细胞后,细胞生长受到明显抑制。与LPS组相比,CA在4,8和16μmol/L时对LPS致RAW264.7细胞损伤具有保护作用。CA可剂量依赖性地降低细胞上清液中一氧化氮(NO)、前列腺素E_(2)(PGE_(2))、肿瘤坏死因子-α(TNF-α)、白介素6(IL-6)和白介素1-β(IL-1β)水平,显示出较好的抗炎作用。动物实验结果表明腹腔注射给予CA(20、40 mg/kg)能明显改善角叉菜胶致小鼠足肿胀程度,也能明显减少醋酸致小鼠扭体次数。结论CA具有良好的抗炎镇痛活性,在炎症疾病领域具有开发价值。
文摘The atmospheric oxidation of a quenched CuZnAlMnNi alloy after ion-polishing was examined by transmission electron microscopy (TEM). It was found that a lot of oxide grains with various sizes yield homogeneously on the surface of the alloy after exposure at room temperature for 90 d. The grains mainly form along the planes of stacking fault, meanwhile, they can also be observed at the stacking fault tetrahedrals or around the dislocation lines. The formation of the oxides gives rise to the reduction of the stacking faults, and even complete disappearance in some zones, which is partly responsible for the decrement of shape memory effect (SME) of the alloy quenched during long-term holding at room temperature.
