Cyanine Polymersomes Inbreathe Gas Signaling Molecule: SO2-Driven Bilayer Tubular Deformation for Transmembrane Traffic Regulation

Fabricating nanoscale assemblies that can respond to gas signaling molecules has emerged as a field of growing interest owing to their unique biomedical applications in gas-guided delivery and gas therapeutics. Yet, among a variety of endogenous gaseous biosignals, exploiting sulfur dioxide (SO₂) as a cue for controllable self-assembly remains elusive, despite its crucial two-sided roles both in physiology and pathology. Here we show a SO₂-responsive polymersome system assembled from a novel class of cyanine-containing block copolymers. By intake of SO₂ gas, the tautomerism of cyanine drives such vesicles to continuously deform, and change into long nanotubes through axial stretching and anisotropic extrusion of the membranes. Unexpectedly, during this order-to-order phase transition, their membranes manifest well SO₂-dose-dependent permselectivity, which allows the cargos of different sizes loaded therein to be selectively transferred across the bilayers. This study would inspire us to better understand and mimic the function of gas signaling molecules in shifting biomembrane shape and managing transmembrane traffic.     

Amorphous Co-P Film: an Efficient Electrocatalyst for Hydrogen Evolution Reaction in Alkaline Seawater

Seawater electrolysis is considered an attractive alternative to conventional freshwater electrolysis for hydrogen production due to the abundance of seawater in nature. For this reason, efficient electrocatalysts for hydrogen evolution reaction (HER) in alkaline seawater are highly desired. In this study, we report an amorphous Co−P alloy on nickel foam (Co−P/NF) that behaves as an efficient and stable HER electrocatalyst for alkaline seawater electrolysis. The Co−P/NF presents high catalytic performance for HER, requiring a low overpotential of 213 mV to drive a current density of 100 mA cm⁻² and a Tafel slope of 120.2 mV dec⁻¹ in alkaline seawater. Furthermore, it shows remarkable electrochemical and structural stability in alkaline seawater.     

多溶剂响应自折叠水凝胶

本文基于寡聚乙二醇甲醚甲基丙烯酸酯(OEGMA)和2-甲基-2-丙烯酸-2-(2-甲氧基乙氧基)乙酯(MEO₂MA)设计了一种自折叠水凝胶. 在室温下,P(MEO₂MA-co-OEGMA)凝胶能够在多种溶剂中自折叠形成三维结构. 凝胶不均匀膨胀导致内应力增强,从而使得片状凝胶可以在三维结构和二维形状之间进行可逆转换. 研究表明,凝胶组成、固化气体环境和成型过程对水凝胶的自折叠过程起着重要的影响.     

Magnetic after-effect in Ni–Mn–Sb Heusler alloy

The ferromagnetic Heusler-type alloy _Ni50Mn35Sb15${\mathrm{Ni}}_{50}{\mathrm{Mn}}_{35}{\mathrm{Sb}}_{15}$ exhibits well defined shape memory behaviour. We have investigated the transport and magnetic properties of this alloy across the martensitic transformation. Pronounced thermo-magnetic irreversibility between zero-field-cooled and field-cooled susceptibility data was observed below the martensitic transition temperature. We observe significant magnetic after-effect in magnetisation in both austenite and martensitic phases. However, a clear change in the nature of relaxation is observed as the sample is cooled across the martensitic transition temperature. These observations can be explained on the basis of complex domain dynamics in presence of rich micro-structure formation in the martensite.     

Experimental study and thermodynamic calculation of Au–Bi–Sb system phase equilibria

Phase equilibria in the Au–Bi–Sb ternary system have been studied experimentally and calculated by the CALPHAD method. Three calculated isopleths with molar ratios Au:Bi=1, Bi:Sb=1 and Au:Sb=1 were compared with the DTA results from this work. The liquidus projection has been calculated. Two ternary invariant reactions were noted. Calculated phase diagram of isothermal section at 573 K was compared with the results of SEM/EDX analysis.     

Shape optimisation of wall structures located in solitary wave flows

ABSTRACT

In this paper, we present a shape optimisation method for wall structures due to the wave force induced by a solitary wave. The fluid is assumed to be incompressible. Introducing the adiabatic assumption in addition, the acoustic velocity method presented by the author's group, the SUPG finite element method, is effectively used. To evaluate the wave force, we use the performance functional, which consists of the sum of the square of the wave force integrated between the starting and final times. The coordinates of the wall structure are regulated to obtain the minimum performance functional. The adjoint equation method is utilised to derive the gradient of the performance functional with respect to the coordinates. The simple weighted gradient method is employed as the minimisation procedure. Two numerical studies show that the results are consistent with existing structures and provide useful information on the practical design of coastal structures.     

Experimental observation of negative differential characteristic of corona discharge in ultraviolet spectrum

Corona discharge is a self-sustained discharge which appears at electrodes with a small radius curvature in gas insulation. An almost invisible glow occurs just above the inception voltage. Corona phenomenon is mainly used in electro-technological processes to obtain space charge for electrostatic precipitation, separation of different particles, electrostatic liquid or solid coating, neutralization of space charge, etc. All of these processes rely on a strong nonhomogeneous electric field generated by a point – plate electrode system. When the critical value of the applied voltage is reached, the ionization processes near the point electrode start and give rise to the current between two electrodes. If the pointed electrode is positive, it is possible to observe an anomaly of the current – voltage (I-U) characteristic for the point-plate space. It means that while the voltage is raising the current density decreases in a narrow voltage area (2–3 kV). The anomaly was technically named as negative differential conductivity (dI/dU < 0). Unstable current can have a negative influence on electro-technological processes. The anomaly was detected for different shapes and materials of the electrode as well as for various temperatures and distances between electrodes. An oxidation layer, which appears on the metal electrode, also influences the ionization processes near the pointed electrode and causes a decrease of a current. In this paper measuring of the discharge activity in a point – plate electrode system is presented. Ionization of gas atoms and molecules in a high electric field and the following recombination of electrons and positive ions in the corona region can give rise to high-energy photons which produce new electrons in the field of discharge. Corona discharges are detected by DayCor Corona camera which can register UV emission generated by corona in a day light. The experiment was conducted with various shapes of the pointed electrode and distances between the high voltage and the grounded electrode under applied direct voltage with positive and negative polarity.     

Growing actin networks regulated by obstacle size and shape

Growing actin networks provide the driving force for the motility of cells and intracellular pathogens. Based on the molecular-level processes of actin polymerization, branching, capping, and depolymerization, we have devel-oped a modeling framework to simulate the stochastic and cooperative behaviors of growing actin networks in pro-pelling obstacles, with an emphasis on the size and shape effects on work capacity and filament orientation in the grow-ing process. Our results show that the characteristic size of obstacles changes the protrusion power per unit length, with-out influencing the orientation distribution of actin filaments in growing networks. In contrast, the geometry of obstacles has a profound effect on filament patterning, which influ-ences the orientation of filaments differently when the drag coefficient of environment is small, intermediate, or large. We also discuss the role of various parameters, such as the aspect ratio of obstacles, branching rate, and capping rate, in affecting the protrusion power of network growth.     

Spline based least squares integration for two-dimensional shape or wavefront reconstruction

In this work, we present a novel method to handle two-dimensional shape or wavefront reconstruction from its slopes. The proposed integration method employs splines to fit the measured slope data with piecewise polynomials and uses the analytical polynomial functions to represent the height changes in a lateral spacing with the pre-determined spline coefficients. The linear least squares method is applied to estimate the height or wavefront as a final result. Numerical simulations verify that the proposed method has less algorithm errors than two other existing methods used for comparison. Especially at the boundaries, the proposed method has better performance. The noise influence is studied by adding white Gaussian noise to the slope data. Experimental data from phase measuring deflectometry are tested to demonstrate the feasibility of the new method in a practical measurement.     

Automatic selection of focal lengths in a Depth From Defocus measurement system based on liquid lenses

A simple and compact Depth-From-Defocus (DFD) setup, using telecentric illumination and liquid-lens based camera observation, was shown to perform well for 3D shape acquisition over extended measuring range. A further step to ameliorate the system performance is described in this paper. We focused on finding an algorithm to speed up the calibration step of the method, that automatically determines the minimum number of focal lengths to be used in the calibration and measurement procedure. As a result, the calibration is significantly shortened (up to 80% with respect to the original procedure), and the need to manually (and to some extent arbitrarily) select the focal length pairs is overcome. Measurement errors down to 0.73 mm over the measurement depth range of 130 mm, corresponding to 0.55% of the depth range are achieved, in total agreement with the original system.