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The glucose transporter 1 (GLUT1) belongs to the major facilitator superfamily (MFS) and is responsible for the constant uptake of glucose. However, the molecular mechanism of sugar transport remains obscure. In this study, homology modeling and molecular dynamics (MD) simulations in lipid bilayers were performed to investigate the combination of the alternate and multisite transport mechanism of glucose with GLUT1 in atomic detail. To explore the substrate recognition mechanism, the outward-open state human GLUT1 homology model was generated based on the template of xylose transporter XylE (PDB ID: 4GBZ), which shares up to 29% sequence identity and 49% similarity with GLUT1. Through the MD simulation study of glucose across lipid bilayer with both the outward-open GLUT1 and the GLUT1 inward-open crystal structure, we investigated six different conformational states and identified four key binding sites in both exofacial and endofacial loops that are essential for glucose recognition and transport. The study further revealed that four flexible gates consisting of W65/Y292/Y293-M420/TM10b-W388 might play important roles in the transport cycle. The study showed that some side chains close to the central ligand binding site underwent larger position changes. These conformational interchanges formed gated networks within an S-shaped central channel that permitted staged ligand diffusion across the transporter. This study provides new inroads for the understanding of GLUT1 ligand recognition paradigm and configurational features which are important for molecular, structural, and physiological research of the MFS members, especially for GLUT1-targeted drug design and discovery.

Barium zirconate titanate (BZT) (Ba(ZrTi)O) ceramics with Zr contents of x = 5, 10, 15, 20, 25, and 30 mol % were prepared using a solid-state reaction approach. The microstructures, morphologies, and electric properties were characterized using X-ray diffraction, scanning electron microscopy, and impedance analysis methods, respectively. The dielectric analyses indicate that the BZT bulk ceramics show characteristics of phase transition from a normal ferroelectric to a relaxor ferroelectric with the increasing Zr ionic content. The electrocaloric effect adiabatic temperature change decreases with the increasing Zr content. The highest adiabatic temperature change obtained is 2.4 K for BZT ceramics with a 5 mol % of Zr ionic content.

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A 61-year (1958–2018) global eddy-resolving dataset for phase 2 of the Ocean Model Intercomparison Project has been produced by the version 3 of Chinese Academy of Science, the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics/Institute of Atmospheric Physics (LASG/IAP) Climate system Ocean Model (CAS-LICOM3). The monthly and a part of the surface daily data in this study can be accessed on the Earth System Grid Federation (ESGF) node. Besides the details of the model and experiments, the evolutions and spatial patterns of large-scale and mesoscale features are also presented. The mesoscale features are reproduced well in the high-resolution simulation, as the mesoscale activities can contribute up to 50% of the total SST variability in eddy-rich regions. Also, the large-scale circulations are remarkably improved compared with the low-resolution simulation, such as the climatological annual mean SST (the RMSE is reduced from 0.59°C to 0.47°C, globally) and the evolution of Atlantic Meridional Overturning Circulation. The preliminary evaluation also indicates that there are systematic biases in the salinity, the separation location of the western boundary currents, and the magnitude of eddy kinetic energy. All these biases are worthy of further investigation.

Abstract(Ba1−xSrx)(MnyTi1−y)O3 (BSMT) ceramics with x = 35, 40 mol% and y = 0, 0.1, 0.2, 0.3, 0.4, 0.5 mol% were prepared using a conventional solid-state reaction approach. The dielectric and ferroelectric properties were characterized using impedance analysis and polarization-electric field (P–E) hysteresis loop measurements, respectively. The adiabatic temperature drop was directly measured using a thermocouple when the applied electric field was removed. The results indicate that high permittivity and low dielectric losses were obtained by doping 0.1–0.4 mol% of manganese ions in (BaSr)TiO3 (BST) specimens. A maximum electrocaloric effect (ECE) of 2.75 K in temperature change with electrocaloric strength of 0.55 K·(MV/m)−1 was directly obtained at ∼21 °C and 50 kV/cm in Ba0.6Sr0.4Mn0.001Ti0.999O3 sample, offering a promising ECE material for practical refrigeration devices working at room temperature.

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The electrocaloric effect (ECE) in dielectrics is characterized by the isothermal entropy change ΔS and adiabatic temperature change ΔT induced by changes of external electric fields. The Maxwell relation, which relates changes of polarization P with temperature T (pyroelectric coefficient) under a fixed electric field E to ΔS for finite intervals in E, provides a convenient way to deduce the ECE from polarization data P(T, E). Hence, this method, known as the indirect method, is widely used in ECE studies in ferroelectrics. Here, we first present the thermodynamic consideration for the Maxwell relation. We then use the indirect method and P(T, E) from bipolar and unipolar polarization curves to deduce the ECE in the normal ferroelectric phase of a P(VDF-TrFE) copolymer. The deduced ECE using the P(T, E) from bipolar polarization curves exhibits a giant negative ECE. In contrast, the directly measured ECE in the same polymer shows the weak and normal ECE. We discuss the constraints of the indirect method and its relation to the polarization–electric field curves measured in practical ferroelectric materials.