Flow Behavior of Entangled Polymer Nanoparticle Composites in a Nanotube: Insights into Jamming State.

Using molecular dynamics simulations, this study investigates the equilibrium properties and flow behaviors of entangled polymer nanoparticle composites (PNCs) within a nanotube. The results show that the density distribution of nanoparticles (NPs), displacement of polymer chains and NPs, and the moduli of PNCs remain relatively unaffected when NP volume fractions (Φ) ≤0.10.

Self-Healing and Shape-Editable Wearable Supercapacitors Based on Highly Stretchable Hydrogel Electrolytes.

Shape editability combined with a self-healing capability and long-term cycling durability are highly desirable properties for wearable supercapacitors. Most wearable supercapacitors have rigid architecture and lack the capacity for editability into desirable shapes. Through sandwiching hydrogel electrolytes between two electrodes, a suite of wearable supercapacitors that integrate desirable properties namely: repeated shape editability, excellent self-healing capability, and long-term cycling durability is demonstrated.

Shear Banding in Entangled Polymers: Stress Plateau, Banding Location, and Lever Rule.

Using molecular dynamics simulation, we study shear banding of entangled polymer melts under a steady shear. The steady shear stress vs shear rate curve exhibits a plateau spanning nearly two decades of shear rates in which shear banding is observed, and the steady shear stress remains unchanged after switching the shear rates halfway in the range of shear rates within the plateau region. In addition, we find strong correlation in the location of the shear bands between different shear rates starting from the same microstate configurations at equilibrium, which suggests the importance of the inherent structural heterogeneity in the entangled polymer network for shear banding.

Local-Average Free Volume Correlates with Dynamics in Glass Formers.

Glass formers exhibit a pronounced slowdown in dynamics, accompanied by progressive heterogeneity as they approach the glass transition. There is intense debate over whether the dramatic slowdown is caused by dynamical heterogeneity and whether the enhanced dynamical heterogeneity originates from structural causes. However, the connection between dynamical heterogeneity and the spatial distribution of the single-particle free volume (a purely static structural quantity) was found to be rather weak, which raises the question of whether dynamic heterogeneity has a purely structural origin.

Critical roles of the activation of ethylene pathway genes mediated by DNA demethylation in Arabidopsis hyperhydricity.

Hyperhydricity (HH) often occurs in plant tissue culture, seriously influencing the commercial micropropagation and genetic improvement. DNA methylation has been studied for its function in plant development and stress responses. However, its potential role in HH is unknown.

Integration of DSF and Temperature Signals for RpfC/RpfG Two-Component System Modulating Protease Production in Stenotrophomonas maltophilia FF11.

Two-component signal system (TCS) is the predominant bacterial sense-and-response machinery. RpfC/RpfG TCS involved in quorum sensing molecule Diffuse Signal Factor (DSF) signal perception and transduction was well studied in many bacteria. However, whether other environmental factors participating in the signal perception and transduction of RpfC/RpfG was still unclear.

Polymer Translocation Time.

The force- and flow-induced translocation processes of linear and ring polymers are studied using a combination of multiparticle collision dynamics and molecular dynamics, focusing on the behavior of the polymer translocation time. We compare the force- and flow-induced translocations of linear and ring polymers. It is found that when the translocation time (τ*) is characterized by scaling exponents, δ, δ', and α, via the relations τ* ∼ and τ* ∼ , the scaling exponents are not constants.

Salt-Induced Liquid-Liquid Phase Separation: Combined Experimental and Theoretical Investigation of Water-Acetonitrile-Salt Mixtures.

Salt-induced liquid-liquid phase separation in liquid mixtures is a common phenomenon in nature and in various applications, such as in separation and extraction of chemicals. Here, we present results of a systematic investigation of the phase behaviors in water-acetonitrile-salt mixtures using a combination of experiment and theory. We obtain complete ternary phase diagrams for nine representative salts in water-acetonitrile mixtures by cloud point and component analysis.

Bone marrow mesenchymal stem cell-derived exosomes promote plasminogen activator inhibitor 1 expression in vascular cells in the local microenvironment during rabbit osteonecrosis of the femoral head.

Background: Nontraumatic osteonecrosis of the femoral head (NONFH) is a highly disabling orthopedic disease in young individuals. Plasminogen activator inhibitor 1 (PAI-1) has been reported to be positively associated with NONFH. We aimed to investigate the dysregulating PAI-1 in bone marrow mesenchymal stem cells (BMMSCs) and vascular cells in rabbit steroid-induced NONFH.

The bacterial potassium transporter gene MbtrkH improves K+ uptake in yeast and tobacco.

K+ is an essential nutrient for plant growth and is responsible for many important physiological processes. K+ deficiency leads to crop yield losses, and overexpression of K+ transporter genes has been proven to be an effective way to resolve this problem. However, current research on the overexpression of K+ transporter genes is limited to plant sources.

Long-term Production of Glycogen and Hepatic-Derived, Cell-Invasion-Promoting Chemokines by Ultrasound-Driven Hepatic-Differentiated Human Bone Marrow Mesenchymal Stem Cells.

The current treatment for liver failure is restricted to surgical liver transplantation, which is technically complicated, limited by the shortage of available organs and presents major risks to the patient. Bone marrow mesenchymal stem cells (BMSCs) represent promising sources of hepatocyte-like cells for cell transplantation treatment. However, a safe and efficient induction method for their differentiation remains to be defined.

Potassium channels and their role in glioma: A mini review.

K channels regulate a multitude of biological processes and play important roles in a variety of diseases by controlling potassium flow across cell membranes. They are widely expressed in the central and peripheral nervous system. As a malignant tumor derived from nerve epithelium, glioma has the characteristics of high incidence, high recurrence rate, high mortality rate, and low cure rate.

Two-step relaxation and the breakdown of the Stokes-Einstein relation in glass-forming liquids.

It is well known that glass-forming liquids exhibit a number of anomalous dynamical phenomena, most notably a two-step relaxation in the self-intermediate scattering function and the breakdown of the Stokes-Einstein (SE) relation, as they are cooled toward the glass transition temperature. While these phenomena are generally ascribed to dynamic heterogeneity, specifically to the presence of slow- and fast-moving particles, a quantitative elucidation of the two-step relaxation and the violation of the SE relation in terms of these concepts has not been successful. In this work, we propose a classification of particles according to the rank order of their displacements (from an arbitrarily defined origin of time), and we divide the particles into long-distance (LD), medium-distance, and short-distance (SD) traveling particle groups.

Transient Deregulation of Canonical Wnt Signaling in Developing Pyramidal Neurons Leads to Dendritic Defects and Impaired Behavior.

During development, the precise implementation of molecular programs is a key determinant of proper dendritic development. Here, we demonstrate that canonical Wnt signaling is active in dendritic bundle-forming layer II pyramidal neurons of the rat retrosplenial cortex during dendritic branching and spine formation. Transient downregulation of canonical Wnt transcriptional activity during the early postnatal period irreversibly reduces dendritic arbor architecture, leading to long-lasting deficits in spatial exploration and/or navigation and spatial memory in the adult.

Individual circular polyelectrolytes under shear flow.

Individual circular polyelectrolytes in simple shear flow are studied by means of mesoscale hydrodynamic simulations, revealing the complex coupling effects of shear rate, electrostatic interaction, and circular architecture on their conformational and dynamical properties. Shear flow deforms the polyelectrolyte and strips condensed counterions from its backbone. A decrease in condensed counterions alters electrostatic interactions among charged particles, affecting shear-induced polymer deformation and orientation.

Ion Polarizabilities in Binary Liquid Mixtures of Water/Organic Solvents.

Using our recently proposed method to obtain salt and ion polarizabilities in aqueous solutions, we determine the polarizabilities of five salts (LiCl, NaCl, NaBr, KBr, and MgSO) in water-acetonitrile, water-ethanol, and water-acetone solutions at eight different water-organic solvent compositions at the D-line of sodium (589.3 ± 0.1 nm).

LotS/LotR/Clp, a novel signal pathway responding to temperature, modulating protease expression via c-di-GMP mediated manner in Stenotrophomonas maltophilia FF11.

Stenotrophomonas maltophilia as one of increasing food spoilage bacteria and fish pathogens has become a threat to aquiculture industry. A major factor contributing to the success of bacterium is its outstanding ability to secrete protease at low temperatures. Here, a cAMP receptor like protein (Clp) shows a positive regulation on this protease, named S.

Eosinophils Mediate Tissue Injury in the Autoimmune Skin Disease Bullous Pemphigoid.

Eosinophils are typically associated with unique inflammatory settings, including allergic inflammation and helminth infections. However, new information suggests that eosinophils contribute more broadly to inflammatory responses and participate in local immune regulation and the tissue remodeling/repair events linked with a variety of diseases. Eosinophilic infiltration has long been a histologic hallmark of bullous pemphigoid (BP), a subepidermal autoimmune blistering disease characterized by autoantibodies directed against basement membrane protein BP180.

Point-to-set dynamic length scale in binary Lennard-Jones glass-formers.

Our recent molecular dynamics simulation results of binary particle glass-former systems demonstrated that the non-monotonic temperature T-dependence of the point-to-set dynamic length scale ξ in harmonic (HM) systems is not an intrinsic property of bulk liquids but originates from wall effects. We would expect our results to apply equally to other simple models, such as Lennard-Jones (LJ) systems. However, Hocky et al.

Nonmonotonic dynamic correlations in quasi-two-dimensional confined glass-forming liquids.

It has been broadly accepted that the behavior of glass-forming liquids, where their relaxation dynamics exhibit a pronounced slowdown as they are cooled toward the glass transition temperature, is caused by the increase in one or more correlation lengths. However, the role of length scales in the dynamics of glass-forming liquids is not clearly established, and past simulation work that suggests a surprising nonmonotonic temperature evolution of spatial dynamical correlations near the mode-coupling crossover temperature has been both questioned and supported by subsequent work. Here, using molecular dynamics simulation, we also show a striking maximum in the dynamic length scale ξ_{c}^{dyn} at a given temperature, but the temperature of this maximum is found to shift as the size of the confined system increases.

Accurate Determination of Ion Polarizabilities in Aqueous Solutions.

We present a novel method for obtaining salt polarizabilities in aqueous solutions based on our recent theory for the refractive index of salt solutions, which predicts a linear relationship between the refractive index and the salt concentration at low concentrations, with a slope determined by the intrinsic values of the salt polarizability and the density of the solution. Here we apply this theory to determine the polarizabilities of 32 strong electrolyte salts in aqueous solutions from refractive index and density measurements. Setting Li as the standard ion, we then determine the polarizabilities of seven cations (Na, K, Rb, Cs, Ca, Ba, and Sr) and seven anions (F, Cl, Br, I, ClO, NO, and SO), which can be used as important reference data.

The influence of polymer architectures on the dewetting behavior of thin polymer films: from linear chains to ring chains.

The dewetting behavior of ring polystyrene (RPS) film and linear polystyrene (LPS) film on silanized Si substrates with different grafting densities and PDMS substrate was investigated. Results showed that polymer architectures greatly influenced the dewetting behavior of the thin polymer film. On the silanized Si substrate with 69% grafting density, RPS chains exhibited stronger adsorption compared with LPS chains, and as a result the wetting layer formed more easily.