Ru nanocrystals modified porous FeOOH nanostructures with open 3D interconnected architecture supported on NiFe foam as high-performance electrocatalyst for oxygen evolution reaction and electrocatalytic urea oxidation.

The construction of binder-free electrodes with well-defined three-dimensional (3D) morphology and optimized electronic structure represents an efficient strategy for the design of high-performance electrocatalysts for the development of efficient green hydrogen technologies. Herein, Ru nanocrystals were modified on 3D interconnected porous FeOOH nanostructures with open network-like frameworks on NiFe foam (Ru/FeOOH@NFF), which were used as an efficient electrocatalyst. In this study, a 3D interconnected porous FeOOH with an open network structure was first electrodeposited on NiFe foam and served as the support for the in-situ modification of Ru nanocrystals. Subsequently, the Ru nanocrystals and abundant oxygen vacancies were simultaneously incorporated into the FeOOH matrix via the adsorption-reduction method, which involved NaBH4 reduction. The Ru/FeOOH@NFF electrocatalyst shows a large specific surface area, abundant oxygen vacancies, and modulated electronic structure, which collectively result in a significant enhancement of catalytic properties with respect to the oxygen evolution reaction (OER) and urea oxidation reaction (UOR). The Ru/FeOOH@NFF catalyst exhibits an outstanding OER performance, requiring a low overpotential (360 mV) at 200 mA cm-2 with a small Tafel slope (58 mV dec-1). Meanwhile, the Ru/FeOOH@NFF catalyst demonstrates more efficient UOR activity for achieving 200 mA cm-2 at a lower overpotential of 272 mV. Furthermore, an overall urea electrolysis cell using the Ru/FeOOH@NFF as the anode and Pt as the cathode (Ru/FeOOH@NFF||Pt) reveals a cell voltage of 1.478 V at 10 mA cm-2 and a prominent durability (120 h at 50 mA cm-2). This work will provide a valuable understanding of the construction of high-performance electrocatalysts with 3D microstructure for promoting urea-assisted water electrolysis.

High-performance flexible asymmetric supercapacitor based on hierarchical MnO2/PPy nanocomposites covered MnOOH nanowire arrays cathode and 3D network-like Fe2O3/PPy hybrid nanosheets anode.

The configuration of asymmetric supercapacitors (ASCs) has proven to be an effective approach to increase the energy storage properties due to the expanded working voltage resulting from the well-separated potential windows of the cathode and anode. However, carbonaceous anode materials generally suffer from relatively low capacitance, which restricts the enhancement of the energy storage performance of the full device in a traditional asymmetrical design. Herein, a rational design of all-pseudocapacitive ASCs (APASCs) using pseudocapacitive materials with a novel hierarchical nanostructure on both electrodes was developed to optimize the electrochemical properties for high-performance ASC devices. The assembled APASC employed the MnO2/PPy nanocomposites covered MnOOH nanowire arrays with core-shell hierarchical architecture as the cathode and Fe2O3/PPy hybrid nanosheets with 3D porous network-like structure as the anode. Owing to the coordinated pseudocapacitive properties and unique hierarchical nanostructures, this assembled APASC exhibited an exceptional volumetric capacitance of 4.92F cm-3 in a stable voltage window of 2 V, a maximum volumetric energy density of 2.66 mWh cm-3 at 19.72 mW cm-3, and excellent cyclic stability over 10,000 cycles (90.6 % capacitance retention), as well as remarkable flexibility and mechanical stability, providing insights for the design of flexible energy storage systems with enhanced performance.

Platelet-Based Nanoparticles with Stimuli-Responsive for Anti-Tumor Therapy.

In addition to hemostasis and coagulation, years of studies have proved that platelets are involved in the whole process of tumor progression, including tumor invasion, intravasation, extravasation, and so on. It means that this property of platelets can be used in anti-tumor therapy. However, traditional platelet-based antitumor drugs often cause autologous platelet damage due to lack of targeting, resulting in serious side effects. Therefore, the researchers designed a variety of anti-tumor drug delivery systems based on platelets by targeting platelets or platelet membrane coating. The drug delivery systems have special response modes, which is crucial in the design of nanoparticles. These modes enhance the targeting and improve the anti-tumor effect. Here, we present a review of recent discoveries in the field of the crosstalk between platelets and tumors and the progress of platelet-based anti-tumor nanoparticles.

Bulk CrCoNiFe alloy with high conductivity and density of grain boundaries for oxygen evolution reaction and urea oxidation reaction.

Multiple-principal-element alloys (MPEAs) with maximized configurational entropy show high catalytic activities for oxygen evolution reaction (OER) and urea oxidation reaction (UOR). However, the accurate relationship between their complex components (i.e., elements, phase structure, grain boundary density) and intrinsic catalytic activity is still unclear. Herein, a series of bulk MPEAs with face-centered cubic (FCC) phase structures were fabricated by the arc-melting method under an argon atmosphere. Compared to the CrCoNi and CrCoNiFeMn, the CrCoNiFe affords a higher UOR performance with the lowest overpotential of 331 mV at 10 mA·cm-2 in 1 M KOH with 0.33 M urea, due to excellent conductivity and high density of grain boundaries. The urea electrolyzer using CrCoNiFe as anode and Pt as cathode shows a low voltage of 1.622 V at 10 mA cm-2 and long-term stability of 60 h at 20 mA cm-2 (4.08% decrease). These findings offer a facile strategy for designing bulk MPEAs electrodes for energy conversion.

Fabrication of High-Performance Colorimetric Membrane by Incorporation of Polydiacetylene into Polyarylene Ether Nitriles Electrospinning Nanofibrous Membranes.

Polyarylene ether nitrile (PEN) is a novel high-performance engineering plastic with various applications, particularly in thermoresistance-required fields. In this study, a well-known stimuli-response polydiacetylene monomer, 10, 12-pentacosadiynoic acid (PCDA), was encapsulated within electrospun PEN nanofibers to fabricate a colorimetric membrane with satisfactory thermal and corrosion resistance. To optimize the compatibility with PCDA, two PENswith distinct molecular chains were utilized: PEN−PPL and PEN−BPA. The chemical structure and elemental mapping analysis revealed that the PCDA component was successfully incorporated into the PEN fibrous. The PCDA bound significantly better to the PEN−PPL than to the PEN−BPA; due to the carboxyl groups present on the side chains of PEN−PPL, the surface was smooth and the color changed uniformly as the temperature rose. However, owing to its poor compatibility with PEN−BPA, the PCDA formed agglomerations on the fibers. The thermal analysis demonstrated that the membranes obtained after PCDA compounding maintained their excellent heat resistance. The 5% weight loss temperatures of composite nanofibrous membranes manufactured by PEN−PPL and PEN−BPA were 402 °C and 506 °C, respectively, and their glass transition temperatures were 219 °C and 169 °C, respectively, indicating that the blended membranes can withstand high temperatures. The evaluation of application performance revealed that the composite membranes exhibited good dimensional stability upon high thermal and corrosive situations. Specifically, the PEN−P−PCDA did not shrink at 170 °C. Both composite membranes were dimensionally stable when exposed to the alkali aqueous solution. However, PEN−P−PCDA is more sensitive to OH−, exhibiting color transition at pH > 8, whereas PEN−B−PCDA exhibited color transition at high OH− concentrations (pH ≥ 13), with enhanced alkali resistance stability owing to its nanofibrous architecture. This exploratory study reveals the feasibility of PEN nanofibers functionalized using PCDA as a desirable stimulus-response sensor even in high-temperature and corrosive harsh environments.

Large-Scale Preparation of Uniform Millet Bread-like Durable Benzoxazine-Phthalonitrile Foam with Outstanding Mechanical and Thermal Properties.

It is essentially important to develop durable polymer foams for services in high-temperature conditions. The current study reported the preparations and properties of a high-performance benzoxazine-phthalonitrile (BZPN) foam by utilizing azodicarbonamide and tween-80 as the blowing agent and stabilizer, respectively. Rheological and curing studies indicated that the appropriate foaming temperature for BZPN foam is below 180 °C, and its foaming viscosity window is below 20 Pa·s. Guided by these results, uniform millet bread-like BZPN foams with decimeter leveling size were successfully realized, suggesting the high prospect of large-scale production. The structural, mechanical, and thermal properties of BZPN foams were then investigated in detail. BZPN foam involves a hierarchical fracture mechanism during the compressive test, and it shows a high compression strength of over 6 MPa. During a burning test over 380 °C, no visible smoke, softening, or droplet phenomena appeared and the macroscopic structure of BZPN foam was well maintained. Mechanically robust, flame-retardant, and uniform large-size BZPN foam are promising light durable materials with high service temperatures, i.e., as filling materials even in a very narrow pipette.

Astragaloside IV attenuated TGF-ß1- induced epithelial-mesenchymal transition of renal tubular epithelial cells via connexin 43 and Akt/mTOR signaling pathway.

INTRODUCTION: The objective of the study was to observe whether connexin 43 (Cx43) could regulate epithelial mesenchymal transformation (EMT) of renal tubular epithelial cells (RTECs) by influencing Akt/mTOR signaling pathway, and whether ASV could inhibit the development of renal interstitial fibrosis by regulating Cx43. METHODS: Lentivirus infection was transfected into RTECs with the final concentration of 50 ×PFU/ cell to regulate the expression of Cx43. And RTECs were intervened by different doses of Astragaloside IV (ASV). After synchronous culture of RTECs in each group，the expression levels of EMT-related indicators and Cx43 were detected by fluorescence microscope and Western-Blotting (WB), even the protein expressions and phosphorylation levels of AKT and mTOR in different groups were detected by WB. RESULTS: When the expression of Cx43 in RTECs was regulated by lentivirus infection, the degree of EMT induced by TGF­ß1 and the phosphorylation level of Akt and mTOR were changed accordingly, indicating that Akt/mTOR pathway might be a downstream molecular mechanism by which Cx43 could regulate EMT. After intervention with different doses of ASV, the expression level of Cx43 increased with obvious concentration dependence, and the expression levels of p-Akt and p- mTOR were significantly altered, suggesting that ASV could effectively increase the protein expressions of TGF­ß1-induced Cx43 in RTECs and inhibit the phosphorylation levels of Akt and mTOR. CONCLUSION: Cx43 were the main material basis of RTECs' injury, and ASV could inhibit TGF-ß1- induced RTECs' transdifferentiation. In-depth study of the mechanism might provide a broad application prospect for the treatment of renal interstitial fibrosis.

Experimental validation for the quasi-shear wave behavior of LiF single crystal along a low-symmetry orientation under uniaxial shock loading.

To investigate the quasi-shear wave behavior and the underlying microscopic mechanism of an anisotropic solid under dynamic deformation beyond its Hugoniot elastic limit, LiF single crystals are shock-compressed along the [310] low-symmetry crystallographic orientation via normal plate-impact method. Interfacial velocity profiles are measured with a Doppler pin system. Peak normal stresses in samples vary between 1.91 GPa and 3.23 GPa. Under the lowest stress in this study, the resultant wave profile shows typical elastoplastic two-wave structures. In the second lowest stress experiment, an irregularity of the plastic wave or the inelastic deformation wave appears in the wave profile. At two higher stresses, a third wave is found following the elastoplastic two waves propagating along the normal direction. Our observations of three-wave structures in the [310] LiF are in excellent agreement with the simulation result of literature. This fact confirms that the immobilization of dislocations and rotation of slip planes are responsible for the microscopic mechanism of the three-wave propagations in the [310] LiF under uniaxial shock loading. The mechanism of the elastoplastic two-wave to anomalous three-wave structures evolution of material under different peak normal stresses will also be discussed.

A 532 nm fiber-optic displacement interferometer for low-velocity impact experiments.

Conventional fiber-optic displacement interferometers operated at 1550 nm suffer from low temporal or velocity resolution for lower velocity measurements. To overcome this drawback, a fiber-optic Doppler pin system operated at 532 nm is developed, and its capability is demonstrated with low-velocity plate impact experiments. The new instrument would be an important supplemental to the existed systems.

[Development of the stroke rehabilitation apparatus based on EMG-biofeedback].

This Stroke Rehabilitation Apparatus uses the electromyography triggered neuromuscular electrical stimulation as the means of the major therapeutics, and the fastigial nucleus stimulation as the means of the assistant therapeutics. This paper introduces the overall structure of the apparatus, the principle of its component, the EMG processing based on local nonlinear projective filtering algorithm and the alternating treatment modes. The therapeutic apparatus has the features of non-invasiveness, safety, convenience and strong alternating capability.