Ce 4+ extraction rate from aqueous sulphate solutions by Cyanex923 in heptane was studied using a constant interfacial cell with laminar flow at 30 ℃. The experimental hydrodynamic conditions were chosen and the...Ce 4+ extraction rate from aqueous sulphate solutions by Cyanex923 in heptane was studied using a constant interfacial cell with laminar flow at 30 ℃. The experimental hydrodynamic conditions were chosen and the contribution of diffusion to the measured rate of reaction was minimized. Cerium extraction rate was measured at different chemical composition by varying the concentrations of hydrogen ion, sulphate and Cyanex923. A cerium Cyanex923(B) extractive is formed at the interface. The data were analyszed in terms of pseudo first order constants and a reaction mechanism was developed.展开更多
The cerium complex bound to the derivative of oligoDNA has been synthesized successfully that can hydrolyze DNA with sequence-specificity. The synthesized derivative of oligoDNA, 5′-EDTA-P-10 mers ODN, was demonstrat...The cerium complex bound to the derivative of oligoDNA has been synthesized successfully that can hydrolyze DNA with sequence-specificity. The synthesized derivative of oligoDNA, 5′-EDTA-P-10 mers ODN, was demonstrated by HPLC. The fluorescence spectrum of Tb3+ was detected after its interaction with the hybrid of 10-mers ODN and 26-mers ODN and the results show that the artificial endo-enzyme can recognize and combine firmly with the substrate DNA. The electrophorogram shows that the cerium-oligoDNA hybrid can specifically hydrolyze its substrate DNA and the cleavage site of this hydrolysis reaction is also discussed. This artificial nuclease can be widely used in molecular biology and genetic engineering as one kind of endo-enzyme.展开更多
Rare earth elements have been extensively used as micro-fertilizers for crops in China. To?understand the potential benefits or damages of Ce4+ on rice, the effects of Ce4+ on viability and membrane integrity of rice ...Rare earth elements have been extensively used as micro-fertilizers for crops in China. To?understand the potential benefits or damages of Ce4+ on rice, the effects of Ce4+ on viability and membrane integrity of rice were investigated under hydroponic cultures. It has been found that the cell viability, electrical conductivity, pH changes, and concentration of malonyl dialdehyde did not change obviously when the content of Ce4+ was 0.5 mg/L, but varied markedly when the contents of Ce4+ were raised to 10 mg/L or more, indicating that the Ce4+ at higher concentrations severely affected the cell membrane permeability.展开更多
文摘Ce 4+ extraction rate from aqueous sulphate solutions by Cyanex923 in heptane was studied using a constant interfacial cell with laminar flow at 30 ℃. The experimental hydrodynamic conditions were chosen and the contribution of diffusion to the measured rate of reaction was minimized. Cerium extraction rate was measured at different chemical composition by varying the concentrations of hydrogen ion, sulphate and Cyanex923. A cerium Cyanex923(B) extractive is formed at the interface. The data were analyszed in terms of pseudo first order constants and a reaction mechanism was developed.
基金This work was supported by the Natural Science Foundation of Shanghai(Grant No.02ZA14068)the Science and Technology Committee of Shanghai(Grant No.011511021).
文摘The cerium complex bound to the derivative of oligoDNA has been synthesized successfully that can hydrolyze DNA with sequence-specificity. The synthesized derivative of oligoDNA, 5′-EDTA-P-10 mers ODN, was demonstrated by HPLC. The fluorescence spectrum of Tb3+ was detected after its interaction with the hybrid of 10-mers ODN and 26-mers ODN and the results show that the artificial endo-enzyme can recognize and combine firmly with the substrate DNA. The electrophorogram shows that the cerium-oligoDNA hybrid can specifically hydrolyze its substrate DNA and the cleavage site of this hydrolysis reaction is also discussed. This artificial nuclease can be widely used in molecular biology and genetic engineering as one kind of endo-enzyme.
文摘Rare earth elements have been extensively used as micro-fertilizers for crops in China. To?understand the potential benefits or damages of Ce4+ on rice, the effects of Ce4+ on viability and membrane integrity of rice were investigated under hydroponic cultures. It has been found that the cell viability, electrical conductivity, pH changes, and concentration of malonyl dialdehyde did not change obviously when the content of Ce4+ was 0.5 mg/L, but varied markedly when the contents of Ce4+ were raised to 10 mg/L or more, indicating that the Ce4+ at higher concentrations severely affected the cell membrane permeability.
