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The realization of a rechargeable zinc-air battery (ZAB) is hindered by the low intrinsic oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) activities. In this work, an abundant built-in electric field is noticed in a 1D/2D CoO/CoS2heterostructure, triggering electron transfer from CoO to CoS2associated with a downshifted d band center of the Co atom mitigating the strong electrochemical adsorption of *OH species on active sites; thereby, boosted OER and ORR performance are achieved. Namely, the OER specific activity of CoO/CoS2is enhanced by 3.8- and 2.2-fold compared to the counterpart of CoO and CoS2, respectively. Furthermore, the kinetic current density of CoO/CoS2, a fingerprint of intrinsic ORR activity, is promoted by 46 and 6.6 times relative to CoO and CoS2. The rechargeable ZAB performance attains 215.6 mW cm–2, 1.6-times better than Pt/C-IrO2. Moreover, the superior performance remained for 600 h. Besides, the battery performance of the all-solid-state ZAB reaches 83.8 mW cm–2, revealing its promising application in wearable device.

Noncontact surface potential measurement approaches with high spatiotemporal resolution are suitable for insulating and conducting materials and have the advantages of noninvasiveness and high sensitivity. These methods show promising application prospects in fields, such as material surface charge imaging. However, reduced electrode size leads to issues such as induction signal attenuation and interference between electrode arrays, limiting the improvement in the spatial resolution and test accuracy. Inspired by the visual principle of lateral inhibition, we propose a biomimetic measurement method that addresses these issues by utilizing the weighted summation of multichannel induction signals and lateral inhibition spatial functions. A lateral inhibition biomimetic circuit is designed, and a circuit parameter calculation method is established. A biomimetic sensor is implemented, and a prototype experimental system is constructed. The proposed method is experimentally validated using test samples featuring line and dot matrix pattern potential distributions. The results indicate that appropriately selected lateral inhibition weights can effectively improve surface potential imaging quality. Optimal weights can increase the structural similarity between the test and simulation results from 0.71 to 0.83 and the peak signal-to-noise ratio from 23.63 to 25.70 dB. The Gershon lateral inhibition function demonstrates higher validity and generality than other inhibition functions.

This paper is concerned with a diffuse interface model called Navier-Stokes/Cahn-Hilliard system. This model is usually used to describe the motion of immiscible two-phase flows with a diffusion interface. For the periodic boundary value problem of this system in torus T3, we prove that there exists a global unique strong solution near the phase separation state, which means that no vacuum, shock wave, mass concentration, interface collision or rupture will be developed in finite time. Furthermore, we establish the large time behavior of the global strong solution of this system. In particular, we find that the phase field decays algebraically to the phase separation state.

Tendon injuries are some of the most commonly diagnosed musculoskeletal diseases. Tendon regeneration is sensitive to the topology of the substitute as it affects the cellular microenvironment and homeostasis. To bionic in vivo three-dimensional (3D) aligned microenvironment, an ordered 3D sandwich model was used to investigate the cell response in the tendon. First, high-resolution 3D printing provided parallel-grooved topographical cues on the hydrogel surface. Then the cells were seeded on its surface to acquire a 2D model. Afterward, an additional hydrogel coating layer was applied to the cells to create the 3D model. The interaction between cells and order structures in three-dimensions is yet to be explored. The study found that the tendon stem/progenitor cells (TSPCs) still maintain their ordering growth in the 3D model as in the 2D model. The study also found that the 3D-aligned TSPCs exhibited enhanced tenogenic differentiation through the PI3K-AKT signaling pathway and presented a less inflammatory phenotype than those in the 2D model. The in vivo implantation of such a 3D-aligned TSPC composite promoted tendon regeneration and mitigated heterotopic ossification in an Achilles defect model. These findings demonstrated that 3D-aligned TSPCs within a biomimetic topology environment are promising for functional tendon regeneration.

The complex electromagnetic environment makes the electromagnetic susceptibility (EMS) test challenging for the unmanned aerial vehicle (UAV) data link. The EMS test can be regarded as an optimization problem to obtain the maximum signal-to-interference ratio that makes the data link losing lock. In this article, we proposed an adaptive EMS test design method based on Bayesian optimization to expand the ability of the EMS test toward the UAV data link. The sensitive electromagnetic interference parameters can be automatically searched according to the adaptive test design method. The Gaussian process is used as the surrogate model for the EMS threshold. Besides, acquisition functions are discussed, including the probability of improvement, expected improvement, and upper confidence bound to balance the exploration and exploitation. Then, two test examples are applied to verify the adaptive test design method. Compared with the traditional EMS test methods, the proposed method introducing Bayesian optimization into the EMS test design can significantly improve the test efficiency and achieve an excellent human-in-the-loop effect.

The battery performance associated with longevity are the priorities for the industrialization of rechargeable zinc air battery (ZAB). Herein, we have reported the construction of WN-CoS2heterostructure enveloped by nitrogen and phosphorus co-doped carbon nanotubes (WN-CoS2@NPCNT). WN-CoS2@NPCNT performs a superior oxygen evolution reaction (OER) catalytic activity of 279 mV overpotential to reach 10 mA cm−2, lowered by 85 mV with relative to CoS2@NCNT attributing to the heterostructure efficiently modulating the electronic structure of active sites. Besides, the half-wave potential reaches 0.875 V vs. RHE for WN-CoS2@NPCNT under oxygen reduction reaction (ORR) condition, corresponding to a 3.2-time higher kinetic current density compared to commercial Pt/C. Due to the exceptional bifunctionality, the battery performance is 205 mW cm−2for WN-CoS2@NPCNT, 1.54 times higher than commercial counterpart, Pt/C + IrO2. Impressively, the battery performance sustains for 1000 h for WN-CoS2@NPCNT stemming from the confinement effect caused by NPCNT. In addition, the all-solid-state ZAB shows a high-power density of 55 mW cm−2.

1,3-dioxolane (DOL) shows low interfacial impedance and high Coulombic efficiency, thus its polymer electrolytes have attracted extensive attention. In order to initiate DOL polymerization, catalyst amount of LiPF6is usually used rather than as the main lithium salt. Totally replacement of LiTFSI with low cost of LiPF6could bring the heat explosion and high viscosity when mixing DOL with 0.9 M LiPF6electrolyte (carbonate ester solvent). Here, based on the Lewis acid-base interaction, a new type of Lewis base, pyridine, is added to control the explosive polymerization of 1,3-dioxolane in LiPF6electrolyte. Through tuning the pyridine content, the gelling process and electrochemical properties could be controlled. It is demonstrated that the optimized monomer conversion and electrochemical window are up to 85.2 % and 4.6 V; meanwhile, the optimized conductivity and transfer number are 0.99 × 10−3 S/cm (25 °C) and 0.68, respectively. The stable interface between PDOL and lithium metal anode could be proved by the stable over-potential (50mv, 700 h) at current density of 0.5 mA cm−2. After 500 cycles at 2C, the assembled Li/PDOL@py0.125/LiFePO4battery delivers 115 mAh/g and 90 % capacity retention, with high average Coulombic efficiency of 99.83 %. The present results demonstrate the heat suppression role of pyridine toward mixing DOL with 0.9 M LiPF6electrolyte, which solves the heat and viscosity problems for PDOL based gelling polymer electrolytes.

The in-situ polymerization of 1,3-dioxolane (PDOL) in battery cells has attracted extensive attention, however, the differences of Lewis acid initiators on the DOL monomer conversion (C%) and electrochemical properties has been ignored. Here, it is demonstrated that compare with Sn(OTf)2Lewis acid initiator, the gelation of DOL is achieved at the lower addition of In(OTf)3. By optimizing their content in the gelation process, their C% are comparable which are 95.7 % and 93.5 % for In(OTf)3and Sn(OTf)2, respectively. However, the higher ionic conductivity (7.1 × 10−4 S cm−1at room temperature), electrochemical window (~4.5 V) and Li+transference number (0.42) are obtained for DOL initiated with In(OTf)3, due to its lower molecular weight which is helpful to the intermolecular Li+transport along PDOL main chain; In addition, the Li/Li symmetrical cell of In(OTf)3can be stably cycled for >500 h at 3 mA cm−2, with an over-potential of 178mv. The storage and cycling impedances of half cells further proves the stable interface of In(OTf)3initiated DOL toward to lithium metal in comparison with those of Sn(OTf)2. Scanning electron microscopy results show a denser and thinner interface in the DOL catalyzed by In(OTf)3. Finally, the assembled Li/LiFePO4battery delivers specific discharge capacity and capacity retention rates of 115.5mAh g−1and 85 %, respectively after 300 cycles at 1C. Through the initiator selection, the DOL synthesis and electrochemical properties can be tuned, which further broadens the design idea of PDOL based solid polymer electrolyte.

The return stroke of cloud‐to‐ground (CG) lightning is an impulsive radiator of very low‐frequency/low‐frequency (VLF/LF) electromagnetic signals allowing for the remote sensing of lower ionosphere over large spatial coverage. In this study, we examined the LF magnetic fields measured in Malacca, Malaysia, to probe reflection heights of the lower ionosphere near the equator on three different nights in 2021. The results show that the virtual ionospheric height at nighttime typically ranged from 82.0 to 90.0 km, with a mean value of 85.3 km. Our measurements also revealed significant variations in the virtual ionospheric height across different regions over a spatial scale of about 800 km. The maximum height difference was about 5.0 km. Moreover, the fluctuation characteristics are observed in both estimated ionospheric height and calculated peak reflection ratio during similar periods. This fluctuation may be related to atmospheric gravity waves in the nighttime ionosphere. In addition, we compared the virtual ionospheric height estimated from CG strokes of different polarities, and the results showed that the virtual reflection height for positive CG strokes is lower than that for negative ones. The ionosphere is the border zone between Earth's atmosphere and exterior space environment. The lowest part of ionosphere, at the altitude range of 60–100 km is particularly tough to measure and impacts both ground‐to‐ground and satellite‐to‐ground communications. Due to the limited coverage range of artificial very low‐frequency and low‐frequency (VLF/LF) techniques by a fixed number of transmitters, the global distribution of broadband radio atmospherics, or sferics, originating from cloud‐to‐ground (CG) lightning strokes has higher detection efficiency. These sferics propagating hundreds of kilometers provide a higher signal‐to‐noise ratio and more detailed information on the lower ionosphere. Currently, the applications of lightning‐induced electromagnetic pulses for remote sensing the lower ionosphere are primarily focused on mid‐to‐high latitude regions. Despite being a hotspot of lightning, there is still a lack of related research in the equatorial areas. Therefore, this study aims to investigate nighttime ionospheric variations using LF magnetic fields generated by lightning strokes in the equatorial region near Malacca, Malaysia, to fill the gap in this field. Our analysis reveals the variation in the virtual reflection height of the equatorial nighttime lower ionosphere by using the magnetic field information contained in lightning sferics and discusses the possible reasons for this variation. Variation in the nighttime lower ionospheric height near the equator is estimated with the measurement of low‐frequency lightning sfericsIonospheric reflection height at night in equatorial region shows significant temporal fluctuation, similar for peak reflection ratioEstimation of nighttime lower ionospheric height appears to considerably depend on the polarity of lightning strokes Variation in the nighttime lower ionospheric height near the equator is estimated with the measurement of low‐frequency lightning sferics Ionospheric reflection height at night in equatorial region shows significant temporal fluctuation, similar for peak reflection ratio Estimation of nighttime lower ionospheric height appears to considerably depend on the polarity of lightning strokes

Differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs) is regulated by a variety of cues of their surrounding microenvironments. In particular, mechanical properties of cell culture matrices have been recently disclosed to play a pivotal role in stem cell differentiation. However, it remains elusive how viscosity affects the chondrogenic differentiation of hMSCs during three-dimensional (3D) culture. In this study, a 3D culture system that was established by embedding viscous gelatin solution in chemically cross-linked gelatin hydrogels was used for 3D culture of hMSCs in gelatin solutions with different viscosities. The influence of solution viscosity on chondrogenic differentiation of hMSCs was investigated. Viscous gelatin solutions promoted cell proliferation in the order of low, middle and high viscosity while elastic hydrogels restricted cell proliferation. High viscosity gelatin solution led to increased production of the cartilaginous matrix. Under the synergistic stimulation of chondrogenic induction factors, high viscosity was beneficial for the chondrogenic differentiation of hMSCs. The results suggested the role of viscosity should be considered as one of the dominant mechanical cues affecting stem cell differentiation. [ABSTRACT FROM AUTHOR]

Efficient and stable electrocatalyst for oxygen evolution reaction (OER) in acidic environment is vital for polymer electrolyte membrane water electrolysis (PEMWE). In this work, we have devised the formation of heterostructured RuO2/MnO2with nanoflower structure for acidic OER catalysis. Compared to commercial RuO2, the overpotential at 50 mA/cm2is decreased by 36 mV, corresponding to a 3.7-fold better mass activity. The boosted acidic OER performance is attributed to the heterostructure inducing more electrons are filled in egorbital of Ru atom triggering a better deprotonation of bridge oxygen atom in Ru-Obri-Mn structure evidenced by pH-independent cyclic voltammetry test. Moreover, RuO2/MnO2sustains its acidic OER activity within 20 h, longer than commercial RuO2. The membrane electrode assembly (MEA) test suggests than only 2.18 V is required to achieve a current density of 5 A/cm2. The theoretical calculation reveals that the egfilling of Ru atom is increased from 2.18 to 2.39 after MnO2incorporation, reducing the energy for the formation of *OOH moiety.

Extracellular matrixes (ECMs) play a vital role in controlling cell functions because of their similarity to the in vivo microenvironment. The composition of ECMs is not constant but dynamically remolded during stem cell differentiation and tissue development. Development of three-dimensional (3D) biomimetic ECM scaffolds is desirable for investigation of ECM–cell interactions and tissue engineering applications. Here, 3D ECM scaffolds that mimicked the dynamic ECM remodeling during stepwise adipogenesis of human mesenchymal stem cells (hMSCs) were developed. A biodegradable hybrid mesh of poly-(dl-lactic-co-glycolic acid) and collagen was used as a template for cell culture. hMSCs were cultured in the hybrid mesh, and their adipogenic differentiation was controlled at early, late, and undifferentiated stages. Three types of stepwise 3D ECM hybrid scaffolds were prepared from the cultured cells after decellularization. They are mesenchymal stem cell ECM scaffold (SC-ECM scaffold), early-stage adipogenesis-mimicking ECM scaffold (EA-ECM scaffold), and late-stage adipogenesis-mimicking ECM scaffold (LA-ECM scaffold). The stepwise 3D ECM scaffolds had a different composition that was dependent on the differentiation stage of hMSCs. They also showed a different influence on the adipogenic differentiation of hMSCs. The EA-ECM scaffold promoted, while the SC-ECM and LA-ECM scaffolds inhibited the adipogenic differentiation of hMSCs.

Low methanol permeability is one of the most critical factors for proton exchange membranes utilized in direct methanol fuel cells (DMFCs). Here, sulfonated poly(ether ether ketone) (SPEEK) polymer chains are interpenetrated into the semi‐interpenetrating polymer networks (semi‐IPNs) constructed by the alkylation reaction between bromobenzyl groups of bromomethylated poly(phenylene oxide) and amine groups of 2,2′‐(ethylenedioxy)bis(ethylamine) cross‐linker. The influences of crosslinking network contents on the key properties of SPEEK membranes are systematically investigated. Dimensional stability and methanol‐permeability resistance are enhanced as the increase of the crosslinking network contents. The relative selectivity is significantly improved due to the largely reduced methanol permeability. The DMFC assembled by the membrane with 20 wt.% crosslinking networks demonstrates four times higher power output than the Nafion 117 DMFC in 5 M methanol solution. SPEEK polymer chains are interpenetrated into the semi‐interpenetrating polymer networks with acid‐base ion pairs to improve dimensional stability and methanol‐permeability resistance. The DMFC assembled by the membrane with 20 wt.% crosslinking networks demonstrates four times higher power output than the Nafion 117 DMFC in 5 M methanol solution.

Poly-γ-l-glutamic acid (PGA) is an outstanding drug carrier candidate owning to its excellent biodegradability and biocompatibility. The PGA carrier may shield toxic drugs from the body and enable the delivery of poorly soluble or unstable drugs and thereby minimize the side effects and improve drug efficacy. However, the limitation of PGA as a drug carrier is low drug loading efficiency (DLE), which is usually below 30%. In this study, we reported a chemical modification method using l-phenylalanine ethyl ester (PAE). PGA–PAE construct was amphiphilic, which could form micelles in aqueous solution. Cisplatin (CDDP), a commonly used chemotherapy drug whose side effect is well-known, was used as a model molecule to test the drug-loading efficiency of PGA–PAE. In this paper, two sizes of CDDP-loaded PGA–PAE micelles (M(Pt)-1 and M(Pt)-2) were prepared, the average diameter of M(Pt)-1 was 106 ± 6 nm and M(Pt)-2 was 210 ± 9 nm. The DLE of M(Pt)-1 and M(Pt)-2 was 52.8 ± 2.2 and 55.8 ± 1.2%, respectively. Both exhibited excellent biocompatibility, stability, and drug-retaining capability in physiological condition. The in vitro accumulative drug-releasing profile, IC50for different tumor cell lines HeLa, A549, and HCCC9810, and in vivo pharmacokinetics were similar between these two micelles; however, M(Pt)-1 showed higher tumor tissue retention and longer efficient cancer cell internalization time (up to 20 d). Our results suggested PGA–PAE micelle carriers reduced the toxicity of CDDP and its size at around 100 nm was the better for CDDP high-efficacy.

The prevailing paradigm of host-parasite evolution is that arms races lead to increasing specialisation via genetic adaptation. Insect herbivores are no exception and the majority have evolved to colonise a small number of closely related host species. Remarkably, the green peach aphid, Myzus persicae, colonises plant species across 40 families and single M. persicaeclonal lineages can colonise distantly related plants. This remarkable ability makes M. persicaea highly destructive pest of many important crop species. To investigate the exceptional phenotypic plasticity of M. persicae, we sequenced the M. persicaegenome and assessed how one clonal lineage responds to host plant species of different families. We show that genetically identical individuals are able to colonise distantly related host species through the differential regulation of genes belonging to aphid-expanded gene families. Multigene clusters collectively upregulate in single aphids within two days upon host switch. Furthermore, we demonstrate the functional significance of this rapid transcriptional change using RNA interference (RNAi)-mediated knock-down of genes belonging to the cathepsin B gene family. Knock-down of cathepsin B genes reduced aphid fitness, but only on the host that induced upregulation of these genes. Previous research has focused on the role of genetic adaptation of parasites to their hosts. Here we show that the generalist aphid pest M. persicaeis able to colonise diverse host plant species in the absence of genetic specialisation. This is achieved through rapid transcriptional plasticity of genes that have duplicated during aphid evolution.

Jasmonates (JAs) are important phytohormones that regulate a wide range of plant processes including growth, development, senescence, and defense. Jasmonate ZIM-domain (JAZ) proteins are repressors in JA signaling. In Arabidopsis thaliana, 12 JAZencoding genes were identified, but only a few have been studied in detail. In this study, we focused on characterizing the molecular networks involving JAZ2and JAZ7. To understand the phenotypes and elucidate the regulatory functions of JAZ2and JAZ7, shoot and root tissues from wild type (WT), jaz2, and jaz7were harvested for RNA sequencing and metabolomics. Distinct changes of transcripts and metabolites in JA biosynthesis, primary and specialized metabolism, and oxidative stress were observed among the three genotypes. In particular, many defense or stress-associated metabolites and specialized metabolites were increased in response to methyl jasmonate (MeJA) treatment. Most importantly, these changes were subjected to quantitative modulation by the JAZ proteins at both transcriptional and metabolic levels, the degree of which may control resource allocation between growth and defense. This study not only reveals MeJA-induced molecular reprogramming but also demonstrates the functions of JAZ proteins as key regulators in fine-tuning JA signal transduction.

Lithium–sulfur batteries are deemed to have the opportunity to replace lithium‐ion batteries because of their high energy density. Nonetheless, the shuttling of soluble long‐chain polysulfides severely deteriorates the cyclic performances of the batteries. Herein, an encapsulated sulfur electrode to tackle the shuttle effect is designed. This high‐performance electrode is fabricated by encapsulating the active sulfur inside a sealing configuration composed of lithiated Nafion (Li‐Nafion), carbon black (BP2000), and a binder of polytetrafluoroethylene. The dense surface of the encapsulated configuration can physically obstruct the mobility of soluble polysulfides. Meanwhile, the sulfonic acid groups fixed on the Li‐Nafion backbone provide a robust electrostatic repulsion to inhibit the negatively charged polysulfides from migrating into the electrolyte. Therefore, the encapsulated sulfur electrode delivers 522.6 mAh g−1at the 600th cycle with a retention of 80.36%, exhibiting a more competitive cyclic stability than the pristine sulfur electrode. A Li‐Nafion‐supported sealing configuration is fabricated to encapsulate the pristine sulfur electrode to confine the polysulfides shuttle effectively. The dense surface of the configuration can physically obstruct the diffusion of soluble polysulfides. Meanwhile, the SO3−groups fixed on the Li‐Nafion backbone provide a robust electrostatic repulsion to prevent the negatively charged polysulfides from migrating into the electrolyte.

Accumulating evidence indicates that stem cell fate can be regulated by mechanical properties of the extracellular matrix. Most studies have focused onthe influence of matrix elasticity and viscoelasticity on stem cell differentiation. However, how matrix viscosity affects stem cell differentiation has been overlooked. In this study, a biphasic gelatin solution/hydrogel system is used for 3D culture of human bone marrow–derived mesenchymal stem cells (MSCs) to investigate the influence of gelatin solution viscosity on simultaneous osteogenic and adipogenic differentiation at the same culture condition. Gelatin solution promotes cell proliferation, while its promotive effect decreases with the increase of viscosity. The influence of viscosity on osteogenic and adipogenic differentiation of MSCs shows opposite trends. A high‐viscosity gelatin solution results in an increase of alkaline phosphatase (ALP) activity, calcium deposition, and expression of osteogenesis‐related genes. On the other hand, in a low‐viscosity gelatin solution, a lot of lipid vacuoles are formed and adipogenesis‐related genes are highly expressed. The results indicate high viscosity is beneficial for osteogenic differentiation, while low viscosity is beneficial for adipogenic differentiation. These findings suggest the importance of matrix viscosity on stem cell differentiation in 3D microenvironments. A 3D biphasic gelatin solution/hydrogel system is used to investigate the influence of solution viscosity on balancing osteogenic and adipogenic differentiation of mesenchymal stem cells (MSCs). The differentiation of MSCs in gelatin solutions is dependent on their viscosities. High viscosity is beneficial for osteogenic differentiation while low viscosity for adipogenic differentiation.

In article number 2000617by Guoping Chen and co‐workers, a 3D biphasic gelatin solution/hydrogel system is used to investigate the influence of solution viscosity on balancing osteogenic and adipogenic differentiation of mesenchymal stem cells (MSCs). The differentiation of MSCs in gelatin solutions is dependent on their viscosities. High viscosity is beneficial for osteogenic differentiation while low viscosity for adipogenic differentiation.

Diamine Cross‐linker on Semi‐Interpenetrating Polymer Networks: The cover feature picture shows the high methanol‐permeability resistance of the semi‐interpenetrating polymer network membranes. In the image, the large fish represent methanol molecules while the small fish stand for protons. The large fish cannot pass through the fishing net, implying the efficient methanol‐permeability resistance of the semi‐interpenetrating polymer networks. More details can be found in the Full Paper by Xupo Liu et al. on page 2264 in Issue 11, 2018(10.1002/ente.201800274).