114 research outputs found
A Gaussian field approach to the solvation of spherical ions in electrolyte solutions
In this work, the electrostatic response of an electrolyte solution to a spherical ion is studied with a Gaussian field theory. In order to capture the ionic correlation effect in concentrated solutions, the bulk dielectric response function is described by a two-Yukawa response function. The modified response function of the solution is solved analytically in the spherical geometry, from which the induced charge density and the electrostatic energy are also derived analytically. Comparisons with results for small ions in electrolyte solutions from the hyper-netted chain theory demonstrate the validity of the Gaussian field theory.This is an accepted manuscript of the article Published as Xiao, Tiejun, and Xueyu Song. "A Gaussian field approach to the solvation of spherical ions in electrolyte solutions." The Journal of Chemical Physics 160, no. 3 (2024). doi: https://doi.org/10.1063/5.0187141. Posted with Permission. Copyright 2024 The Authors
Recommended from our members
Parallelization and I/O performance optimization of a global nonhydrostatic dynamical core using MPI
The Global ‐ Regional Integrated forecast SysTem (GRIST) is the next-
generation weather and climate integrated model dynamic framework developed by
Chinese Academy of Meteorological Sciences. In this paper, we present several changes
made to the global nonhydrostatic dynamical (GND) core, which is part of the ongoing
prototype of GRIST. The changes leveraging MPI and PnetCDF techniques were targeted
at the parallelization and performance optimization to the original serial GND core.
Meanwhile, some sophisticated data structures and interfaces were designed to adjust
flexibly the size of boundary and halo domains according to the variable accuracy in
parallel context. In addition, the I/O performance of PnetCDF decreases as the number of
MPI processes increases in our experimental environment. Especially when the number
exceeds 6000, it caused system-wide outages (SWO). Thus, a grouping solution was
proposed to overcome that issue. Several experiments were carried out on the
supercomputing platform based on Intel x86 CPUs in the National Supercomputing
Center in Wuxi. The results demonstrated that the parallel GND core based on grouping
solution achieves good strong scalability and improves the performance significantly, as
well as avoiding the SWOs
A Stochastic Programming Approach for an Enhanced Performance of a Multi-committees Byzantine Fault Tolerant Algorithm
Entropy production in a mesoscopic chemical reaction system with oscillatory and excitable dynamics
Stochastic thermodynamics of chemical reaction systems has recently gained
much attention. In the present paper, we consider such an issue for a system
with both oscillatory and excitable dynamics, using catalytic oxidation of
carbon monoxide on the surface of platinum crystal as an example. Starting from
the chemical Langevin equations, we are able to calculate the stochastic
entropy production P along a random trajectory in the concentration state
space. Particular attention is paid to the dependence of the time averaged
entropy productionP on the system sizeN in a parameter region close to the
deterministic Hopf bifurcation.In the large system size (weak noise) limit, we
find that P N^{\beta} with {\beta}=0 or 1 when the system is below or abovethe
Hopf bifurcation, respectively. In the small system size (strong noise) limit,
P always increases linearly with N regardless of the bifurcation parameter.
More interestingly,P could even reach a maximum for some intermediate system
size in a parameter region where the corresponding deterministic system shows
steady state or small amplitude oscillation. The maximum value of P decreases
as the system parameter approaches the so-called CANARD point where the maximum
disappears.This phenomenon could be qualitativelyunderstood by partitioning the
total entropy production into the contributions of spikes and of small
amplitude oscillations.Comment: 13 pages, 6 figure
Influence of Global Warming on the RC Structures and Durability Monitoring in Civil Engineering
Intestinal Microbiota-Derived GABA Mediates Interleukin-17 Expression during Enterotoxigenic Escherichia coli Infection
Intestinal microbiota has critical importance in pathogenesis of intestinal infection; however, the role of intestinal microbiota in intestinal immunity during enterotoxigenic Escherichia coli (ETEC) infection is poorly understood. The present study tested the hypothesis that the intestinal microbiota is associated with intestinal interleukin-17 (IL-17) expression in response to ETEC infection. Here, we found ETEC infection induced expression of intestinal IL-17 and dysbiosis of intestinal microbiota, increasing abundance of γ-aminobutyric acid (GABA)-producing Lactococcus lactis subsp. lactis. Antibiotics treatment in mice lowered the expression of intestinal IL-17 during ETEC infection, while GABA or L. lactis subsp. lactis administration restored the expression of intestinal IL-17. L. lactis subsp. lactis administration also promoted expression of intestinal IL-17 in germ-free mice during ETEC infection. GABA enhanced intestinal IL-17 expression in the context of ETEC infection through activating mechanistic target of rapamycin complex 1 (mTORC1)-ribosomal protein S6 kinase 1 (S6K1) signaling. GABA–mTORC1 signaling also affected intestinal IL-17 expression in response to Citrobacter rodentium infection and in drug-induced model of intestinal inflammation. These findings highlight the importance of intestinal GABA signaling in intestinal IL-17 expression during intestinal infection and indicate the potential of intestinal microbiota-GABA signaling in IL-17-associated intestinal diseases
Modeling a New Water Channel That Allows SET9 to Dimethylate p53
SET9, a protein lysine methyltransferase, has been thought to be capable of transferring only one methyl group to target lysine residues. However, some reports have pointed out that SET9 can dimethylate Lys372 of p53 (p53-K372) and Lys4 of histone H3 (H3-K4). In order to understand how p53 can be dimethylated by SET9, we measured the radius of the channel that surrounds p53-K372, first on the basis of the crystal structure of SET9, and we show that the channel is not suitable for water movement. Second, molecular dynamic (MD) simulations were carried out for 204 ns on the crystal structure of SET9. The results show that water leaves the active site of SET9 through a new channel, which is made of G292, A295, Y305 and Y335. In addition, the results of molecular docking and MD simulations indicate that the new water channel continues to remain open when S-adenosyl-L-methionine (AdoMet) or S-adenosyl-L-homocysteine (AdoHcy) is bound to SET9. The changes in the radii of these two channels were measured in the equilibrium phase at the constant temperature of 300 K. The results indicate that the first channel still does not allow water to get into or out of the active site, but the new channel is large enough to allow this water to circulate. Our results indicate that water can be removed from the active site, an essential process for allowing the dimethylation reaction to occur
- …