Fully Band Resolved Scattering Rate in MgB2 Revealed by Nonlinear Hall Effect and Magnetoresistance Measurements

We have measured the normal state temperature dependence of the Hall effect and magnetoresistance in epitaxial MgB2 thin films with variable disorders characterized by the residual resistance ratio RRR ranging from 4.0 to 33.3. A strong nonlinearity of the Hall effect and magnetoresistance have been found in clean samples, and they decrease gradually with the increase of disorders or temperature. By fitting the data to the theoretical model based on the Boltzmann equation and ab initio calculations for a four-band system, for the first time, we derived the scattering rates of these four bands at different temperatures and magnitude of disorders. Our method provides a unique way to derive these important parameters in multiband systems.Comment: 4 pages, 4 figure

Mesenchymal stem cells alleviate bacteria‐induced liver injury in mice by inducing regulatory dendritic cells

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102718/1/hep26670.pd

The scaling of charging rate and cycle number of commercial batteries

Health management for commercial batteries is crowded with a variety of great issues, among which reliable cycle-life prediction tops. By identifying the cycle life of commercial batteries with different charging histories in fast-charging mode, we reveal that the average charging rate c and the resulted cycle life N of batteries obey c = c(0)N(b), where c(0) is a limiting charging rate and b is an electrode-dependent constant. This c-N law, resembling the classic stress versus cycle number relationship (the S-N curve or Wohler curve) of solids subject to cyclic loading, could be applicable to most batteries. Such a scaling law, in combination with a physics-augmented machine-learning algorithm, could foster the predictability of battery life with high fidelity. The scaling of charging rate and cycle number may pave the way for cycle-life prediction and the directions of optimization of advanced batteries

Regulation of anionic lipids in binary membrane upon the adsorption of polyelectrolyte: A Monte Carlo simulation

We employ Monte Carlo simulations to investigate the interaction between an adsorbing linear flexible cationic polyelectrolyte and a binary fluid membrane. The membrane contains neutral phosphatidyl–choline, PC) and multivalent anionic (phosphatidylinositol, PIP2) lipids. We systematically study the influences of the solution ionic strength, the chain length and the bead charge density of the polyelectrolyte on the lateral rearrangement and the restricted mobility of the multivalent anionic lipids in the membrane. Our findings show that, the cooperativity effect and the electrostatic interaction of the polyelectrolyte beads can significantly affect the segregation extent and the concentration gradients of the PIP2 molecules, and further cooperate to induce the complicated hierarchical mobility behaviors of PIP2 molecules. In addition, when the polyelectrolyte brings a large amount of charges, it can form a robust electrostatic well to trap all PIP2 and results in local overcharge of the membrane. This work presents a mechanism to explain the membrane heterogeneity formation induced by the adsorption of charged macromolecule

Compositional redistribution and dynamic heterogeneity in mixed lipid membrane induced by polyelectrolyte adsorption: Effects of chain rigidity

Monte Carlo simulation is employed to investigate the interaction between a polyelectrolyte and a fluid mixed membrane containing neutral (phosphatidyl-choline, PC), monovalent anionic (phosphatidylserine, PS), and multivalent anionic (phosphatidylinositol, PIP2) lipids. The effects of the intrinsic polyelectrolyte rigidity and solution ionic strength on the lateral rearrangement and dynamics of different anionic lipid species are systematically studied. Our results show that, the increase of polyelectrolyte chain rigidity reduces the loss of polyelectrolyte conformational entropy and the energy gains in electrostatic interaction, but raises the demixing entropy loss of the segregated anionic lipids. Therefore, the polyelectrolyte/membrane adsorption strength exhibits a non-monotonic dependence on the polyelectrolyte rigid parameter k ang, and there exists a certain optimal k ang for which the adsorption strength is maximal. Because the less loss of chain conformational entropy dominates the increase of the demixing entropy loss of the segregated anionic lipids and the decreases of the electrostatic energy gains, the semiflexible polyelectrolyte adsorbs onto the membrane more firmly than the flexible one. Whereas, for the adsorption of rigid polyelectrolyte, larger anionic lipid demixing entropy loss and less energy gain in the electrostatic interaction dominate over the decrease of the polyelectrolyte conformation entropy loss, leading to the desorption of the chain from the membrane. By decreasing the ionic concentration of the salt solution, the certain optimal k ang shifts to larger values. The cooperative effects of the adsorbing polyelectrolyte beads determine the concentration gradients and hierarchical mobility of the bound anionic lipids, as well as the polyelectrolyte dynamics

Correction to “Monte Carlo Simulation on Complex Formation of Proteins and Polysaccharides”

Correction to “Monte Carlo Simulation on Complex Formation of Proteins and Polysaccharides

The scaling of charging rate and cycle number of commercial batteries

Health management for commercial batteries is crowded with a variety of great issues, among which reliable cycle-life prediction tops. By identifying the cycle life of commercial batteries with different charging histories in fast-charging mode, we reveal that the average charging rate c and the resulted cycle life N of batteries obey c = c(0)N(b), where c(0) is a limiting charging rate and b is an electrode-dependent constant. This c-N law, resembling the classic stress versus cycle number relationship (the S-N curve or Wohler curve) of solids subject to cyclic loading, could be applicable to most batteries. Such a scaling law, in combination with a physics-augmented machine-learning algorithm, could foster the predictability of battery life with high fidelity. The scaling of charging rate and cycle number may pave the way for cycle-life prediction and the directions of optimization of advanced batteries

Monte Carlo Simulation on Complex Formation of Proteins and Polysaccharides

In protein–polysaccharide complex systems, how nonspecific interactions such as electrostatic and van der Waals interactions affect complex formation has not been clearly understood. On the basis of a coarse-grained model with the specificity of a target system, we have applied Monte Carlo (MC) simulation to illustrate the process of complex coacervate formation from the association of proteins and polysaccharides. The coarse-grained model is based on serum albumin and a polycation system, and the MC simulation of pH impact on complex coacervation has been carried out. We found that complex coacervates could form three ways, but the conventional association through electrostatic attraction between the protein and polysaccharide still dominated the complex coacervation in such systems. We also observed that the depletion potential always participated in protein crowding and was weakened in the presence of strong electrostatic interactions. Furthermore, we observed that the sizes of polysaccharide chains nonmonotonically increased with the number of bound proteins. Our approach provides a new way to understand the details during protein–polysaccharide complex coacervation at multiple length scales, from interaction and conformation to aggregation

Spatial Rearrangement and Mobility Heterogeneity of an Anionic Lipid Monolayer Induced by the Anchoring of Cationic Semiflexible Polymer Chains

We use Monte Carlo simulations to investigate the interactions between cationic semiflexible polymer chains and a model fluid lipid monolayer composed of charge-neutral phosphatidyl-choline (PC), tetravalent anionic phosphatidylinositol 4,5-bisphosphate (PIP2), and univalent anionic phosphatidylserine (PS) lipids. In particular, we explore how chain rigidity and polymer concentration influence the spatial rearrangement and mobility heterogeneity of the monolayer under the conditions where the cationic polymers anchor on the monolayer. We find that the anchored cationic polymers only sequester the tetravalent PIP2 lipids at low polymer concentrations, where the interaction strength between the polymers and the monolayer exhibits a non-monotonic dependence on the degree of chain rigidity. Specifically, maximal anchoring occurs at low polymer concentrations, when the polymer chains have an intermediate degree of rigidity, for which the PIP2 clustering becomes most enhanced and the mobility of the polymer/PIP2 complexes becomes most reduced. On the other hand, at sufficiently high polymer concentrations, the anchoring strength decreases monotonically as the chains stiffen—a result that arises from the pronounced competitions among polymer chains. In this case, the flexible polymers can confine all PIP2 lipids and further sequester the univalent PS lipids, whereas the stiffer polymers tend to partially dissociate from the monolayer and only sequester smaller PIP2 clusters with greater mobilities. We further illustrate that the mobility gradient of the single PIP2 lipids in the sequestered clusters is sensitively modulated by the cooperative effects between anchored segments of the polymers with different rigidities. Our work thus demonstrates that the rigidity and concentration of anchored polymers are both important parameters for tuning the regulation of anionic lipids