The standard electromotive forces of the reversible cells consisted of the Corning monovalent general cation selective electrode (M + ISE) and chloride selective electrode (Cl ISE), namely Cl --ISE｜RbCl( m ),H 2O(1- ...The standard electromotive forces of the reversible cells consisted of the Corning monovalent general cation selective electrode (M + ISE) and chloride selective electrode (Cl ISE), namely Cl --ISE｜RbCl( m ),H 2O(1- x ),DMF( x )｜M +-ISE have been measured, and the standard free energies of transfer(Δ S t ) of RbCl from H 2O to mixtures of H 2O DMF have been calculated, the standard transfer entropies(Δ S t ) have been also calculated from temperature coefficients of Δ G t of RbCl at seven temperatures from 283.15 K to 318.15 K. The behavior of change of Δ S t of RbCl with experimental temperature and mole fraction ( x ) of DMF in the mixed solvents and its influence on the structure of the mixed solvents were discussed on the basis of solvation theory ofelectrolyte solution.展开更多
Metallothionein, a class of low molecular weight, metal- and cysteine-rich Proteins, are postulated to play a central role in metal-related biological processes such as the detoxification of Cd2+and Pb2+. The thermal ...Metallothionein, a class of low molecular weight, metal- and cysteine-rich Proteins, are postulated to play a central role in metal-related biological processes such as the detoxification of Cd2+and Pb2+. The thermal Properties of the interactions of rabbit liver Zn7MT2 and apo-MT2 with Cd2+ and Pb2+ were studied using isothermal titration calorimeter. The same product Cd7MT formed in the reactions of Cd2+ with Zn7MT2 and apo-MT2, while the reactions of Ph2+ with Zn7MT2 and apo-MT2 Produced two MT species Ph7MT and Ph7MT’. The thermodynamic parameters （△H、 △G、 △S, etc. ） for the reactions of MT with 1 mol metal ions were measured at 293. 15 K, pH 4.70. All of these reachons are spontaneous, exothermic processes. The values of △G and K show that Cd2+ is more affinitive to MT than Ph2+. The equilibrium constants K of the replacement reactions of Zn7MT2 by 1 mol Cd2+ and Pb2+ are 2. 7×105 and 1. 3×105 respectively, that means the concentrations of free Cd2+ and Pb2+ are depressed to about 1. 0×10-5 after the reactions with Zn7MT2. These data can be used to evaluate quantitatively the ability of MT in Cd2+ and Ph2+ detoxificatio.展开更多
文摘The standard electromotive forces of the reversible cells consisted of the Corning monovalent general cation selective electrode (M + ISE) and chloride selective electrode (Cl ISE), namely Cl --ISE｜RbCl( m ),H 2O(1- x ),DMF( x )｜M +-ISE have been measured, and the standard free energies of transfer(Δ S t ) of RbCl from H 2O to mixtures of H 2O DMF have been calculated, the standard transfer entropies(Δ S t ) have been also calculated from temperature coefficients of Δ G t of RbCl at seven temperatures from 283.15 K to 318.15 K. The behavior of change of Δ S t of RbCl with experimental temperature and mole fraction ( x ) of DMF in the mixed solvents and its influence on the structure of the mixed solvents were discussed on the basis of solvation theory ofelectrolyte solution.
文摘Metallothionein, a class of low molecular weight, metal- and cysteine-rich Proteins, are postulated to play a central role in metal-related biological processes such as the detoxification of Cd2+and Pb2+. The thermal Properties of the interactions of rabbit liver Zn7MT2 and apo-MT2 with Cd2+ and Pb2+ were studied using isothermal titration calorimeter. The same product Cd7MT formed in the reactions of Cd2+ with Zn7MT2 and apo-MT2, while the reactions of Ph2+ with Zn7MT2 and apo-MT2 Produced two MT species Ph7MT and Ph7MT’. The thermodynamic parameters （△H、 △G、 △S, etc. ） for the reactions of MT with 1 mol metal ions were measured at 293. 15 K, pH 4.70. All of these reachons are spontaneous, exothermic processes. The values of △G and K show that Cd2+ is more affinitive to MT than Ph2+. The equilibrium constants K of the replacement reactions of Zn7MT2 by 1 mol Cd2+ and Pb2+ are 2. 7×105 and 1. 3×105 respectively, that means the concentrations of free Cd2+ and Pb2+ are depressed to about 1. 0×10-5 after the reactions with Zn7MT2. These data can be used to evaluate quantitatively the ability of MT in Cd2+ and Ph2+ detoxificatio.
