According to the nonequilibrium solvation theory studies, a constrained equilibrium principle is introduced and applied to the derivations of the nonequilibrium solvation energy, and a reasonable expression of the spe...According to the nonequilibrium solvation theory studies, a constrained equilibrium principle is introduced and applied to the derivations of the nonequilibrium solvation energy, and a reasonable expression of the spectral shift of the electronic absorption spectra is deduced. Furthermore, the lowest transition of p-nitroaniline （pNA） in water is investigated by time-dependent density functional theory method. In addition, the details of excited state properties of pNA are discussed. Using our novel expression of the spectral shift, the value of -0.99 eV is obtained for π→π^＊ transition in water, which is in good agreement with the available experimental result of -0.98 eV.展开更多
When species in the solution undergo multiple chemical reactions, the solution may be treated as a solution of all species actually present or as a hypothetical solution composed of elemental species. Based on the fu...When species in the solution undergo multiple chemical reactions, the solution may be treated as a solution of all species actually present or as a hypothetical solution composed of elemental species. Based on the fundamental thermodynamic principle, the relationships of mole numbers, molar fractions, thermodynamic properties, partial molar properties, potential and fugacity between the hypothetical solution of elemental species and the equilibrated solution of actual species were derived. The hypothetical elemental solution provides a way of reducing the dimensionality of problem, simplifying the analysis and visualizing the phase behavior.展开更多
A novel algorithm was designed and implemented to realize the numerical calculation of the solvent reorganization energy for electron transfer reactions, on the basis of nonequilibrium solvation theory and the dielect...A novel algorithm was designed and implemented to realize the numerical calculation of the solvent reorganization energy for electron transfer reactions, on the basis of nonequilibrium solvation theory and the dielectric polarizable continuum model. Applying the procedure to the well-investigated intramoleeular electron transfer in biphenyl-androstane-naphthyl and biphenyl-androstane-phenanthryl systems, the numerical results of solvent reorganization energy were determined to be around 60 k J/mol, in good agreement with experimental data. Koopman＇s theorem was adopted for the calculation of the electron transfer coupling element, associated with the linear reaction coordinate approximation. The values for this quantity obtained are acceptable when compared with experimental results.展开更多
Major histocompatibility complex （MHC） is a family of highly polymorphic genes activating adaptive immunity in vertebrates. However, the underlying mecha- nism of MHC evolution is still not fully understood. In this...Major histocompatibility complex （MHC） is a family of highly polymorphic genes activating adaptive immunity in vertebrates. However, the underlying mecha- nism of MHC evolution is still not fully understood. In this study, we investigated genetic variation of three classical MHC class I genes in the giant panda （Ailuropoda mela- noleuca） and tested for selection effect and recombination event across exonic and intronic sequences to understand maintenance mechanism of polymorphism at Aime-MHC class I genes. In total, we isolated 21 MHC class I haplotypes （exon 2-intron 2-exon 3） from 46 captive giant pandas, of which eight were for Aime-C, seven for Aime-I and six for Aime-L; however, we only identified six unique sequences from these haplotypes. The subsequent maximum-likeli- hood and Chi-square analyses both detected evidence of recombination acting on the 21 haplotypes. These results indicate that the giant panda still retains a relatively high adaptive variation at Aime-MHC-I genes, and that the intronic segments have been homogenized along evolu- tionary time by recombination and subsequent genetic drift.We calculated nucleotide substitution rates of the antigen- binding regions （exons 2 and 3） and the noncoding intron 2, and found two pieces of evidence supporting the presence of balancing selection in the giant panda： an excess of nonsynonymous over synonymous substitutions at the antigen-binding sites, and an obviously higher synonymous substitutions in the exons than nucleotide substitutions in the intron. Thus, this study reveals that balancing selection and recombination together shape the diversity pattern at Aime- MHC-I loci of the giant panda.展开更多
基金ACKNOWLEDGMENTS This work was supported Science Foundation of China by the National Natural （No.91016002）.
文摘According to the nonequilibrium solvation theory studies, a constrained equilibrium principle is introduced and applied to the derivations of the nonequilibrium solvation energy, and a reasonable expression of the spectral shift of the electronic absorption spectra is deduced. Furthermore, the lowest transition of p-nitroaniline （pNA） in water is investigated by time-dependent density functional theory method. In addition, the details of excited state properties of pNA are discussed. Using our novel expression of the spectral shift, the value of -0.99 eV is obtained for π→π^＊ transition in water, which is in good agreement with the available experimental result of -0.98 eV.
基金Supported by the National Natural Science Foundation of China (No. 29976035) and the Natural Science Foundation of Zhejiang and Fujian Province.
文摘When species in the solution undergo multiple chemical reactions, the solution may be treated as a solution of all species actually present or as a hypothetical solution composed of elemental species. Based on the fundamental thermodynamic principle, the relationships of mole numbers, molar fractions, thermodynamic properties, partial molar properties, potential and fugacity between the hypothetical solution of elemental species and the equilibrated solution of actual species were derived. The hypothetical elemental solution provides a way of reducing the dimensionality of problem, simplifying the analysis and visualizing the phase behavior.
文摘A novel algorithm was designed and implemented to realize the numerical calculation of the solvent reorganization energy for electron transfer reactions, on the basis of nonequilibrium solvation theory and the dielectric polarizable continuum model. Applying the procedure to the well-investigated intramoleeular electron transfer in biphenyl-androstane-naphthyl and biphenyl-androstane-phenanthryl systems, the numerical results of solvent reorganization energy were determined to be around 60 k J/mol, in good agreement with experimental data. Koopman＇s theorem was adopted for the calculation of the electron transfer coupling element, associated with the linear reaction coordinate approximation. The values for this quantity obtained are acceptable when compared with experimental results.
基金supported by a special grant(SG1411)for the giant panda from the State Forestry Administration of China
文摘Major histocompatibility complex （MHC） is a family of highly polymorphic genes activating adaptive immunity in vertebrates. However, the underlying mecha- nism of MHC evolution is still not fully understood. In this study, we investigated genetic variation of three classical MHC class I genes in the giant panda （Ailuropoda mela- noleuca） and tested for selection effect and recombination event across exonic and intronic sequences to understand maintenance mechanism of polymorphism at Aime-MHC class I genes. In total, we isolated 21 MHC class I haplotypes （exon 2-intron 2-exon 3） from 46 captive giant pandas, of which eight were for Aime-C, seven for Aime-I and six for Aime-L; however, we only identified six unique sequences from these haplotypes. The subsequent maximum-likeli- hood and Chi-square analyses both detected evidence of recombination acting on the 21 haplotypes. These results indicate that the giant panda still retains a relatively high adaptive variation at Aime-MHC-I genes, and that the intronic segments have been homogenized along evolu- tionary time by recombination and subsequent genetic drift.We calculated nucleotide substitution rates of the antigen- binding regions （exons 2 and 3） and the noncoding intron 2, and found two pieces of evidence supporting the presence of balancing selection in the giant panda： an excess of nonsynonymous over synonymous substitutions at the antigen-binding sites, and an obviously higher synonymous substitutions in the exons than nucleotide substitutions in the intron. Thus, this study reveals that balancing selection and recombination together shape the diversity pattern at Aime- MHC-I loci of the giant panda.
