Some thermodynamic properties of NHk fixation by loess soil in plowing and clay layers are discussed.The. results indicate that the four ion adsorption equations commonly used can describe the properties of NHk fixati...Some thermodynamic properties of NHk fixation by loess soil in plowing and clay layers are discussed.The. results indicate that the four ion adsorption equations commonly used can describe the properties of NHk fixation in these soils under constant temperature. Among the four adsorption equations, the singlesurface Langmuir equation is the best. When the concentration of NH4Cl solution is 10-1 mol below, the Freundlich equation can be used.The changes of apparent standard free energy (△Go), enthalpy (△Ho) and entropy (△So) illustrate that NHk fixation in soil is an endothermic adsorption and spontaneous reaction, and the process can be enhanced by a higher temperature and clay content in soil.The "proper value of NHk fixation by soil (K1×qm) increased with increasing clay content and temperature. The heat of NHk fixation in soil (Qm) confirms the conclusions made in this paper.展开更多
Influenza A(A/H_(x)N_(y))is a significant public health concern due to its high infectiousness and mortality.Neuraminidase,which interacts with sialic acid(SIA)in host cells,has become an essential target since its hi...Influenza A(A/H_(x)N_(y))is a significant public health concern due to its high infectiousness and mortality.Neuraminidase,which interacts with sialic acid(SIA)in host cells,has become an essential target since its highly conserved catalytic center structure,while resistance mutations have already generated.Here,a detailed investigation of the drug resistance mechanism caused by mutations was performed for subtype N9(A/H7N9).Molecular dynamics simulation and alanine-scanning-interaction-entropy method(ASIE)were used to explore the critical differences between N9 and Zanamivir(ZMR)before and after R294K mutation.The results showed that the mutation caused the hydrogen bond between Arg294 and ZMR to break,then the hydrogen bonding network was disrupted,leading to weakened binding ability and resistance.While in wild type(A/H7N9^(WT)),this hydrogen bond was initially stable.Meanwhile,N9 derived from A/H11N9 was obtained as an R292K mutation.Then the relative binding free energy of N9 with five inhibitors(SIA,DAN,ZMR,G28,and G39)was predicted,basically consistent with experimental values,indicating that the calculated results were reliable by ASIE.In addition,Arg292 and Tyr406 were hot spots in the A/H11N9^(WT)-drugs.However,Lys292 was not observed as a favorable contributing residue in A/H11N9^(R292K),which may promote resistance.In comparison,Tyr406 remained the hotspot feature when SIA,ZMR,and G28 binding to A/H11N9^(R292K).Combining the two groups,we speculate that the resistance was mainly caused by the disruption of the hydrogen bonding network and the transformation of hotspots.This study could guide novel drug delivery of drug-resistant mutations in the treatment of A/H_(x)N9.展开更多
The standard Gibbs energies of transfer (Δ tr G 0) for potassium tetraphenylborate (KBPh 4) have been studied in the systems of water and water +1 propanol (PrOH) as well as water and water + t butyl alcohol (TBA) at...The standard Gibbs energies of transfer (Δ tr G 0) for potassium tetraphenylborate (KBPh 4) have been studied in the systems of water and water +1 propanol (PrOH) as well as water and water + t butyl alcohol (TBA) at 298.15?K. The results show that -Δ tr G 0 exhibits a complicated changing pattern with the mole fraction of TBA( x (TBA)) or PrOH ( x (PrOH)), and Δ tr G 0 has the a maximum value at x (TBA) = 0.2 or x (PrOH)=0.2. Especially, -Δ tr G 0 of KBPh 4 changes unusually with increasing x (TBA) when x (TBA) < 0.05. The reasons for these changes were analyzed and discussed.展开更多
We study the entropy of Schwarzschild-de Sitter black holes based on generalized uncertainty principle with brick-wall method by counting degrees of freedom near the horizons and obtain the entropy proportional to the...We study the entropy of Schwarzschild-de Sitter black holes based on generalized uncertainty principle with brick-wall method by counting degrees of freedom near the horizons and obtain the entropy proportional to the surface area at the horizons without cut-off. And reveal the possible value of the minimum length.展开更多
文摘Some thermodynamic properties of NHk fixation by loess soil in plowing and clay layers are discussed.The. results indicate that the four ion adsorption equations commonly used can describe the properties of NHk fixation in these soils under constant temperature. Among the four adsorption equations, the singlesurface Langmuir equation is the best. When the concentration of NH4Cl solution is 10-1 mol below, the Freundlich equation can be used.The changes of apparent standard free energy (△Go), enthalpy (△Ho) and entropy (△So) illustrate that NHk fixation in soil is an endothermic adsorption and spontaneous reaction, and the process can be enhanced by a higher temperature and clay content in soil.The "proper value of NHk fixation by soil (K1×qm) increased with increasing clay content and temperature. The heat of NHk fixation in soil (Qm) confirms the conclusions made in this paper.
基金supported by the National Natural Science Foundation of China(No.11774207)。
文摘Influenza A(A/H_(x)N_(y))is a significant public health concern due to its high infectiousness and mortality.Neuraminidase,which interacts with sialic acid(SIA)in host cells,has become an essential target since its highly conserved catalytic center structure,while resistance mutations have already generated.Here,a detailed investigation of the drug resistance mechanism caused by mutations was performed for subtype N9(A/H7N9).Molecular dynamics simulation and alanine-scanning-interaction-entropy method(ASIE)were used to explore the critical differences between N9 and Zanamivir(ZMR)before and after R294K mutation.The results showed that the mutation caused the hydrogen bond between Arg294 and ZMR to break,then the hydrogen bonding network was disrupted,leading to weakened binding ability and resistance.While in wild type(A/H7N9^(WT)),this hydrogen bond was initially stable.Meanwhile,N9 derived from A/H11N9 was obtained as an R292K mutation.Then the relative binding free energy of N9 with five inhibitors(SIA,DAN,ZMR,G28,and G39)was predicted,basically consistent with experimental values,indicating that the calculated results were reliable by ASIE.In addition,Arg292 and Tyr406 were hot spots in the A/H11N9^(WT)-drugs.However,Lys292 was not observed as a favorable contributing residue in A/H11N9^(R292K),which may promote resistance.In comparison,Tyr406 remained the hotspot feature when SIA,ZMR,and G28 binding to A/H11N9^(R292K).Combining the two groups,we speculate that the resistance was mainly caused by the disruption of the hydrogen bonding network and the transformation of hotspots.This study could guide novel drug delivery of drug-resistant mutations in the treatment of A/H_(x)N9.
文摘The standard Gibbs energies of transfer (Δ tr G 0) for potassium tetraphenylborate (KBPh 4) have been studied in the systems of water and water +1 propanol (PrOH) as well as water and water + t butyl alcohol (TBA) at 298.15?K. The results show that -Δ tr G 0 exhibits a complicated changing pattern with the mole fraction of TBA( x (TBA)) or PrOH ( x (PrOH)), and Δ tr G 0 has the a maximum value at x (TBA) = 0.2 or x (PrOH)=0.2. Especially, -Δ tr G 0 of KBPh 4 changes unusually with increasing x (TBA) when x (TBA) < 0.05. The reasons for these changes were analyzed and discussed.
基金Supported by National Natural Science Foundation of China under Grant Nos.11275099,11435006,11405130the Double FirstClass University Construction Project of Northwest University
文摘We study the entropy of Schwarzschild-de Sitter black holes based on generalized uncertainty principle with brick-wall method by counting degrees of freedom near the horizons and obtain the entropy proportional to the surface area at the horizons without cut-off. And reveal the possible value of the minimum length.
