Investigating the Regulation of Neural Differentiation and Injury in PC12 Cells Using Microstructure Topographic Cues.

In this study, we designed and manufactured a series of different microstructure topographical cues for inducing neuronal differentiation of cells in vitro, with different topography, sizes, and structural complexities. We cultured PC12 cells in these microstructure cues and then induced neural differentiation using nerve growth factor (NGF). The pheochromocytoma cell line PC12 is a validated neuronal cell model that is widely used to study neuronal differentiation.

Reduced Ionic Conductivity but Enhanced Local Ionic Conductivity in Nanochannels.

The ionic transport in nanoscale channels with the critical size comparable to ions and solvents shows excellent performance on electrochemical desalination, ion separation, and supercapacitors. However, the key quantity ionic conductivity (σ) in the nanochannel that evaluates how easily the electric current is driven by an external voltage is still unknown because of the challenges in experimental measurement. In this work, we present an atomistic simulation-based study, which shows that how the ion concentration, nanoconfinement, and heterogeneous solvation modify the ionic conductivity in a two-dimensional graphene nanochannel.

Numerical study of the effect of LVAD inflow cannula positioning on thrombosis risk.

Left ventricular assist devices (LVADs) have been increasingly used as a therapy for patients with end-stage heart failure. However, a growing number of clinical observations have shown that LVADs are associated with thromboembolic events, which are potentially related to the changes in intraventricular flow. Particularly, the flow fields around the inflow cannula (IC) of the LVAD.

Effect of Direct Fluorination on the Transport Properties and Swelling of Polymeric Materials: A Review.

Fluorine-containing polymers occupy a peculiar niche among conventional polymers due to the unique combination of physicochemical properties. Direct surface fluorination of the polymeric materials is one of the approaches for the introduction of fluorine into the chemical structure that allows one to implement advantages of fluorinated polymers in a thin layer. Current review considers the influence of the surface interaction of the polymeric materials and membranes with elemental fluorine on gas, vapor and liquid transport as well as swelling and related phenomena.

Effects of substrate stiffness on mast cell migration.

Mast cells (MCs) play important roles in multiple pathologies, including fibrosis; however, their behaviors in different extracellular matrix (ECM) environments have not been fully elucidated. Accordingly, in this study, the migration of MCs on substrates with different stiffnesses was investigated using time-lapse video microscopy. Our results showed that MCs could appear in round, spindle, and star-like shapes; spindle-shaped cells accounted for 80-90 % of the total observed cells.

Influence of particle-fluid density ratio on the dynamics of finite-size particles in homogeneous isotropic turbulent flows.

In this paper, direct numerical simulations of particle-laden homogeneous isotropic turbulence are performed using lattice Boltzmann method incorporating interpolated bounce-back scheme. Four different particle-fluid density ratios are considered to explore how particles with different particle-fluid density ratios respond to the turbulence. Overall particle dynamics in the homogeneous isotropic turbulence such as the Lagrangian statistics of single particle and the preferential concentration of particles are investigated.

Critical Evaluation of Various Spontaneous Polarization Models and Induced Electric Fields in III-Nitride Multi-Quantum Wells.

In this paper, ab initio calculations are used to determine polarization difference in zinc blende (ZB), hexagonal (H) and wurtzite (WZ) AlN-GaN and GaN-InN superlattices. It is shown that a polarization difference exists between WZ nitride compounds, while for H and ZB lattices the results are consistent with zero polarization difference. It is therefore proven that the difference in Berry phase spontaneous polarization for bulk nitrides (AlN, GaN and InN) obtained by Bernardini et al.

Mechanical activation of spike fosters SARS-CoV-2 viral infection.

The outbreak of SARS-CoV-2 (SARS2) has caused a global COVID-19 pandemic. The spike protein of SARS2 (SARS2-S) recognizes host receptors, including ACE2, to initiate viral entry in a complex biomechanical environment. Here, we reveal that tensile force, generated by bending of the host cell membrane, strengthens spike recognition of ACE2 and accelerates the detachment of spike's S1 subunit from the S2 subunit to rapidly prime the viral fusion machinery.

Continuous Water Filling in a Graphene Nanochannel: A Molecular Dynamics Study.

Low dimensional materials especially carbon materials hold high promise in the fields of water purification, mineral separation, energy harvesting/conversion, and so on. The fluidic devices fabricated by direct synthesis, lithography, or self-assembly of low dimensional materials provide opportunities for exploring the novel properties and applications of nanoconfined transport. Here, continuous filling of water and acetone molecules into a graphene nanochannel is investigated.

Effect of misfit strain on the buckling of graphene/MoSvan der Waals heterostructures.

Van der Waals heterostructures inherit many novel electronic and optical properties from their constituent atomic layers. Mechanical stability is key for realizing high-performance nanodevices based on van der Waals heterostructures. However, buckling instability is a critical mechanical issue for heterostructures associated with its two-dimensional nature.

On limits of contact tracing in epidemic control.

Contact tracing and quarantine are well established non-pharmaceutical epidemic control tools. The paper aims to clarify the impact of these measures in evolution of epidemic. The proposed deterministic model defines a simple rule on the reproduction number [Formula: see text] in terms of ratio of diagnosed cases and, quarantine and transmission parameters.

Time-domain analysis of a three-dimensional numerical model of the human spiral cochlea at medium intensity.

For the processing and detection of speech and music, the human cochlea has an exquisite sensitivity and selectivity of frequency and a dynamic range. How the cochlea performs these remarkable functions has fascinated auditory scientists for decades. Because it is not possible to measure sound-induced vibrations within the cochlea in a living human being, mathematical modeling has played an important role in cochlear mechanics.

Role of soft bi-layer coating on the protection of turtle carapace.

The turtle carapace is a biological armor exhibiting enhanced protection performance. Despite considerable efforts to characterize the structure-property relations of the turtle carapace, how the design of soft keratin-collagen bi-layer coating contributes to the protection of this biological armor remains largely unknown. In this study, calculations are carried out for fracture of the turtle carapace subjected to impact loading.

A potential barrier in the diffusion of nanoparticles in ordered polymer networks.

Diffusion of nanoparticles (NPs) in a polymer matrix is of significant importance in diverse research fields, such as bio-engineering and nano-technology. Although the prediction of the effective diffusivity has been extensively explored, it remains a great challenge for theoretical investigation. In the present study, the single-particle Dissipative Particle Dynamics (DPD) is employed to study the diffusion of nanoparticles in an unentangled ordered polymer network.

Appearance of Temporal and Spatial Chaos in an Ecological System: A Mathematical Modeling Study.

The ecological theory of species interactions rests largely on the competition, interference, and predator-prey models. In this paper, we propose and investigate a three-species predator-prey model to inspect the mutual interference between predators. We analyze boundedness and Kolmogorov conditions for the non-spatial model.

Effects of incomplete inter-hospital network data on the assessment of transmission dynamics of hospital-acquired infections.

In the year 2020, there were 105 different statutory insurance companies in Germany with heterogeneous regional coverage. Obtaining data from all insurance companies is challenging, so that it is likely that projects will have to rely on data not covering the whole population. Consequently, the study of epidemic spread in hospital referral networks using data-driven models may be biased.

Modeling and Simulation in Capacity Degradation and Control of All-Solid-State Lithium Battery Based on Time-Aging Polymer Electrolyte.

The prediction of electrochemical performance is the basis for long-term service of all-solid-state-battery (ASSB) regarding the time-aging of solid polymer electrolytes. To get insight into the influence mechanism of electrolyte aging on cell fading, we have established a continuum model for quantitatively analyzing the capacity evolution of the lithium battery during the time-aging process. The simulations have unveiled the phenomenon of electrolyte-aging-induced capacity degradation.

Experimental data on fracture of open-hole composite laminates subjected to tension loading.

In this data article, we present detailed failure process of big open-hole carbon fibre reinforced polymer (CFRP) composite laminates subjected to tension loading, which are tested by digital image correlation (DIC) system and electrical strain gauge system. In experiments, three different lay-ups are applied tension loading until specimens' failure. Several strain gages are distributed in different locations of specimens to measure strains during loading, at the same time, DIC is adopted to obtain field strains of specimens.

Magnetism-Responsive Anisotropic Film with Self-Sensing and Multifunctional Shape Manipulation.

At small scales, shape-programmable magnetic materials and self-sensing conductive materials have an enticing potential for realizing the functionalities that are unattainable by traditional machines. This work reports a facile preparation method of aself-sensing magnetism-responsive anisotropic films (SMAF) in which magnetic materials and conductive materials can be predesigned, oriented, and patterned without requiring an external magnetic field generator or other expensive devices. A variety of shaped magnetoactive films with complex chain-orientation structures that can achieve advanced actuation functions have been developed, such as magnetically driven flowers, windmills, and leaves.

Evolution of populations with strategy-dependent time delays.

We study the effects of strategy-dependent time delays on the equilibria of evolving populations. It is well known that time delays may cause oscillations in dynamical systems. Here we report a novel behavior.

Relevance of intra-hospital patient movements for the spread of healthcare-associated infections within hospitals - a mathematical modeling study.

The aim of this study is to analyze patient movement patterns between hospital departments to derive the underlying intra-hospital movement network, and to assess if movement patterns differ between patients at high or low risk of colonization. For that purpose, we analyzed patient electronic medical record data from five hospitals to extract information on risk stratification and patient intra-hospital movements. Movement patterns were visualized as networks, and network centrality measures were calculated.

Energetics of stochastic BCM type synaptic plasticity and storing of accurate information.

Excitatory synaptic signaling in cortical circuits is thought to be metabolically expensive. Two fundamental brain functions, learning and memory, are associated with long-term synaptic plasticity, but we know very little about energetics of these slow biophysical processes. This study investigates the energy requirement of information storing in plastic synapses for an extended version of BCM plasticity with a decay term, stochastic noise, and nonlinear dependence of neuron's firing rate on synaptic current (adaptation).

Anomalous shape effect of nanosized helium bubble on the elastic field in irradiated tungsten.

Bubble pressure and elastic response in helium-irradiated tungsten are systematically investigated in this study. An anomalous shape effect is found that the radial normal stress and mean stress distributions around a nanosized void or bubble are far from the spherical symmetry, which is ascribed to polyhedral geometry characteristic of the nanosized bubble and physical mechanism transition from crystal surfaces dominated to the surface ledges and triple junctions dominated. Molecular simulation shows that Young-Laplace equation is not suitable for directly predicting equilibrium pressure for nanosized bubble in crystals.

Polycrystalline Few-Layer Graphene as a Durable Anticorrosion Film for Copper.

Corrosion of metals in atmospheric environments is a worldwide problem in industry and daily life. Traditional anticorrosion methods including sacrificial anodes or protective coatings have performance limitations. Here, we report atomically thin, polycrystalline few-layer graphene (FLG) grown by chemical vapor deposition as a long-term protective coating film for copper (Cu).