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In this work, a glucose-derived carbon supported CrN composite is prepared by using a hydrothermal method and followed by a nitridating process. It is found that CrN nanoparticles in the composite are well-dispersed and separated by the carbon support. More importantly, the composite exhibits significantly enhanced oxygen reduction reaction activity than free-standing aggregated CrN nanoparticles, especially in acidic medium. The onset potential of the composite reaches 0.81 V in acidic medium, which is one of the highest values among the reported metal nitrides. The rotating ring disk electrode results indicate that the composite is more beneficial to O 2 dissociation than free-standing CrN nanoparticles. Results of X-ray photoelectron spectroscopy, O 2 temperature-programmed desorption and electrochemical impedance spectroscopy indicate that the significantly enhanced oxygen reduction reaction activity of the composite over free-standing CrN is derived not from the new formed active sites or enhanced oxygen adsorption but from the much enhanced electron transfer rate. This observation helps to understand the role of electron transfer rate playing in the oxygen reduction reaction activity of metal nitrides. Image 1 • Glucose-derived carbon supported well-dispersed CrN nanoparticles are prepared. • The ORR onset potential of the catalyst reaches 0.81 V in acidic medium. • The catalyst shows much enhanced ORR activity than aggregated CrN nanoparticles. • The catalyst is more beneficial to O 2 dissociation than aggregated CrN. • The much enhanced ORR activity is attributed to enhanced electron transfer rate. [ABSTRACT FROM AUTHOR]

Background: Salvia miltiorrhiza Bunge (S. miltiorrhiza), a traditional Chinese medicine, has demonstrated antioxidant, anti-inflammatory, and antibacterial activities. However, its effects against asthma that shows chronic inflammation and oxidative damage remain unknown.Purpose: To assess the effects of S. miltiorrhiza extracts on airway responsiveness, inflammation, and remodeling in ovalbumin (OVA)-induced asthmatic mice.Methods: Mice with ovalbumin (OVA)-induced allergic asthma were treated with S. miltiorrhiza extracts, and airway resistance (RL) to methacholine, inflammatory cell infiltration, Th1/Th2 cytokine levels, and airway remodeling were assessed. TGF-β1-induced BEAS-2B and MRC-5 cells were used to evaluate the effects of five S. miltiorrhiza compounds on epithelial-mesenchymal transition and fibrosis.Results: OVA-challenge resulted in remarkably increased RL, inflammatory cell infiltration, Th1/Th2 cytokine levels in BALF, goblet cell hyperplasia, collagen deposition, and airway wall thickening. Daily treatment with S. miltiorrhiza ethanolic (EE, 246 mg/kg) or water (WE, 156 mg/kg) extract significantly reduced OVA-induced airway inflammatory cell infiltration, Th1/Th2 cytokine amounts, and goblet cells hyperplasia. However, only WE remarkably decreased RL, collagen deposition, and airway wall thickening. Moreover, Chromatography showed that salvianic acid A and caffeic acid levels were much higher in WE than EE, while rosmarinic acid was slightly lower; salvianolic acid B and tanshinone IIA levels were much higher in EE than WE. Interestingly, caffeic acid and rosmarinic acid were more potent in reducing E-cadherin and vimentin levels in TGF-β1-induced BEAS-2B cells, and α-SMA and COL1A1 amounts in TGF-β1-induced MRC-5 cells.Conclusions: Both S. miltiorrhiza WE and EE alleviate airway inflammation in mice with OVA-sensitized allergic asthma. S. miltiorrhiza WE is more potent in reducing responsiveness and airway remodeling. [ABSTRACT FROM AUTHOR]

Aluminum oxynitride (AlON) ceramic was fabricated by in-situ hot pressing sintering (HPS) from Al 2 O 3 and AlN doped with Y 2 O 3 and La 2 O 3 as well as without dopant for comparison. Dense AlON ceramic with a relative density of 99.7% was obtained by HPS doped with 0.4 wt% Y 2 O 3 and 0.1 wt% La 2 O 3 at 1700 °C for 4 h. The maximum fracture toughness of AlON ceramic with and without dopant was 3.74 MPa m 1/2 and 2.27 MPa m 1/2 , respectively. The maximum Vickers hardness of AlON ceramic with and without dopant was 18.3 GPa and 16.5 GPa, respectively. Compared with those of undoped AlON ceramic, the relative density and the fracture toughness of Y 2 O 3 -La 2 O 3 co-doped AlON ceramic were obviously improved. Overlarge grain size would reduce the Vickers hardness of AlON. The sintering activation energy of Y 2 O 3 -La 2 O 3 co-doped AlON was about 57% of that of undoped AlON. The sintering activity of AlON was highly improved by co-doping with Y 2 O 3 and La 2 O 3 . [ABSTRACT FROM AUTHOR]

Aluminum oxynitride (AlON) ceramics were fabricated by spark plasma sintering (SPS) from Al 2 O 3 , AlN and different concentrations of Y 2 O 3 . Fully dense and single-phase AlON ceramics were obtained in a sample doped with 0.6 wt% Y 2 O 3 sintered at 1600 °C. A proper amount of Y 2 O 3 additive can reduce sintering activation energy and enhance sintering activity due to plasma activated effects. Excess Y 2 O 3 would result in the formation of Y 3 Al 5 O 12 (YAG) as a second phase which decreased grain boundary mobility and prevented grain growth. Vickers hardness slightly increased from 15.9 to 18.1 GPa, whereas fracture toughness firstly increased and then decreased with increased Y 2 O 3 concentration. This work demonstrates that the combination of doping Y 2 O 3 and SPS method will produce fully dense AlON ceramics with improved performance at relatively low temperature (1600 °C). It is notable that Y 2 O 3 concentration shall be about 0.6 wt%. SPS of AlON doped with Y 2 O 3 is a rate controlled sintering. [ABSTRACT FROM AUTHOR]

Highlights: [•] F/Sn and Al co-doped ZnO thin films were synthesized by sol–gel method. [•] The co-doped nanocrystals exhibit good crystal quality. [•] The origin of the photoluminescence emissions was discussed. [•] The films showed high transmittance and low resistivity. [ABSTRACT FROM AUTHOR]

Abstract: Yttrium oxide (Y2O3) transparent ceramics samples have been successfully fabricated by microwave sintering processing at relatively low temperatures. In comparison with the vacuum sintering processing, Y2O3 transparent ceramics can be obtained by microwave sintering at lower sintering temperature and shorter sintering time, and they possess higher transmittances and mechanical properties. The technologies of low-temperature microwave sintering and the relationships of the microstructures and properties of the specified samples have been investigated in detail. We have found out that the low-temperature microwave sintering technique has its obvious advantages over the conventional methods in manufacturing yttrium oxide transparent ceramics. [Copyright &y& Elsevier]

The iron-nitrogen co-doped carbon (Fe–N–C) materials have considered one of the oxygen reduction reaction catalysts with the best potential. Unfortunately, their insufficient intrinsic activity and low active sites result in thick cathode catalytic layers of fuel cell, which has limited discharge performance of the Fe–N–C catalysts in the fuel cells. Herein, a supramolecular assembly strategy is designed to prepare accessible Fe-N x sites and ultra-fine Fe 3 C nanoparticles in porous carbon nanosheet with optimized pore structure toward oxygen reduction electrocatalysis. It is found that supramolecular assembly strategy has significantly increased the specific surface area and Fe-N x site content, and induced the formation of highly dispersed Fe 3 C nanoparticles, which contributes to the high electrochemical active surface area and catalytic activity. The obtained FeNC-900-S catalyst exhibits a high half-wave potential of 0.860 V and a current density of up to 8.28 mA/cm2 (J k at 0.85 V) in 0.1 M KOH, outperforming the those of commercial Pt/C. More importantly, when the FeNC-900-S is employed as an air cathode catalyst towards zinc-air batteries, it obtains an open-circuit voltage of 1.548 V, a power density of 188.8 mW/cm2 and a specific capacity of 790.5 mAh/g. A supramolecular assembly strategy is designed to prepare accessible Fe 3 C/Fe-N x sites in porous carbon nanosheet, and it exhibits a half-wave potential of 0.86 V in 0.1 M KOH, with a power density of 188.8 mW/cm2 for zinc-air battery. [Display omitted] • A highly accessible Fe 3 C@Fe-N x active sites in porous carbon nanosheet is prepared via a supramolecular assembly strategy. • The melamine-cyanuric acid supramolecular promoted the formation of highly active sites and porosity. • The FeNC-900-S obtains high ORR activity in 0.1 M KOH, and zinc-air battery exhibits a power density of 188.8 mW cm−2. [ABSTRACT FROM AUTHOR]

Novel nanoporous g-C 3 N 4 /MnTiO 3 heterojunctions were synthesized by hydrothermal method using nanoporous g-C 3 N 4 and nano-MnTiO 3 as the raw materials. The effects of g-C 3 N 4 content on phase, microstructure and photocatalytic activity for dye degradation were studied. Hydrothermal synthesized nanoporous g-C 3 N 4 /MnTiO 3 (abbreviated as HS-CN/MT) exhibited facets coupling, well-structured heterojunctions with intimate interface, which displayed enhanced absorption intensity of visible light, as well as improved separation and migration efficiency of photogenerated carriers. The adsorption rate of HS-CN/MT for methylene blue gradually increased, while its photocatalytic degradation rate initially increased and subsequently decreased with increasing g-C 3 N 4 content. HS-CN/MT with 65 wt% g-C 3 N 4 presented the highest degradation rate constant of 0.0411 min −1 , which was up to 14.5, 2.4, and 3.9 times as high as that of bulk g-C 3 N 4 , nanoporous g-C 3 N 4 and mechanical mixed nanoporous g-C 3 N 4 /MnTiO 3 . EIS spectra revealed that HS-65CN/MT exhibited the highest separation efficiency of hole-electron pairs. Active specie capture experiments proved that OH and O 2 ¯ were the main active species, which indicated the HS-CN/MT with significantly enhanced photocatalytic performance exhibited a direct Z-scheme heterojunction mechanism, because it retained higher oxidation and reduction potentials while preventing the electron-hole pairs recombination. These were essentially attributed to the intimate contact of nanoporous g-C 3 N 4 /MnTiO 3 heterojunctions, which resulted from the synergistic effects of nanoporous adsorption and hydrothermal interaction. [ABSTRACT FROM AUTHOR]

Highlights: [•] BaO was introduced into the Ni-GDC anode of integral SOFC. [•] BaO/Ni-GDC has higher coking resistance and lower polarization than Ni-GDC. [•] The maximum power density of SOFC with BaO/Ni-GDC anode at 750°C is 824mWcm−2. [ABSTRACT FROM AUTHOR]

[Display omitted] • The infiltration reduction of the thermal barrier coating is achieved maintaining the internal porous structure and its thermal isolation capability. • A sealed layer is designed to hinder the molten calcium–magnesium–alumina–silicate infiltration into the porous ceramic coatings. • Three different sealing layers were studied, showing the capabilities of each one in the improvement of the hot corrosion resistance. Thermal barrier coatings (TBCs) can improve the high-temperature performance of turbine blades, however, the complex service environment such as Ca-Mg-Al-silicate (CMAS) is the main reason for the coating failure. The corrosive medium (Ca2+ and Si4+) penetrates the TBCs through the porous structure combined with surface defects. In this study, three different sealed layers (Zr, Al, and Al-Y) were deposited on the traditional TBCs by using magnetron sputtering. The cross-sectional morphologies showed the continuous structure of the sealed layer improved the pore filling effect. When O 2 is adsorbed at the top position of the Al atom, the lowest adsorption energy of the YAl 3 (0001) surface is −5.34 eV which can provide stronger chemical adsorption energies for Al and O. The Al-Y sealed layer was preferred to form an aluminum oxide film. The experimental results of CMAS corrosion showed that Al-Y sealed layer can achieve long-lasting protection because the aluminum yttrium oxide (Al 2 Y 4 O 9) reacts with CaO and SiO 2 at the interface and finally formed Ca 3 Y 2 (SiO 4) 6 O 2 , resulting in rapid crystallization of CMAS. [ABSTRACT FROM AUTHOR]

Direct methanol fuel cells (DMFCs) had been attracted considerable attention for its advantages of high energy density, simplified systems and readily transportation and storage of methanol. However, the notoriously sluggish kinetics of methanol oxidation reaction (MOR) of the anode reaction, had greatly affected the commercialization of DMFCs. On one hand, Pt based catalyst are still the most effective MOR catalysts, while the high cost caused by the high loadings of electrocatalyst to compensate the low MOR activity impedes the wide accessible of DMFCs. In addition, the occurrence of catalyst poisoning owing to the strong interaction between Pt and carbon monoxide (CO) generated during the MOR processing, further leading to the fast decay in the performance and stability of MOR electrocatalysts. Two-dimensional (2D) Pt based nanostructures is regarded to be one promising and effective class of MOR electrocatalysts, and attracted much attention due to the high electron mobility, highly exposed active sites, and extraordinary thermal conduction. In this review, the mechanism of MOR was firstly introduced, and then the synthesis conditions, structure characteristics and methanol oxidation performances both in acidic and alkaline dielectric of 2D Pt based nanocatalysts were introduced. Subsequently, we briefly analyzed the structural characteristics of 2D Pt based nanocatalysts and their advantages, including the low platinum loadings, high specific surface area and majority of atomic active sites exposed. Finally, the opportunities and challenges for designing of advanced 2D Pt based nanocatalysts was proposed and discussed. [Display omitted] • Recent advances of 2D Pt-based catalysts for methanol oxidation reaction (MOR) were introduced. • Some strategies for improving the MOR performance of 2D Pt-based catalysts were summarized. • The challenges and prospective were provided in detail for 2D Pt-based catalysts. [ABSTRACT FROM AUTHOR]

Memantine is a non-competitive antagonist of glutamatergic NMDA receptor that is mainly used in the treatment of Alzheimer's disease. The excitatory toxicity mediated by glutamate via glutamatergic receptor signals is considered to be one of the mechanisms mediating neuronal injury and cognitive impairment after exposure to a hypoxic environment at a high altitude. Therefore, in this study, we hypothesized that inhibiting glutamate signaling using memantine could alleviate neuronal injury and cognitive impairment in rats exposed to chronic hypoxia. we made animal models in the natural environment of the Qinghai-Tibet Plateau at an altitude of 4300 m, and used animal behavior, morphology, molecular biology and other methods to evaluate the impact of chronic hypoxia exposure on cognitive function and the neuroprotective effect of Memantine. Our results showed that the expression of NMDA receptors increased, while the expression of AMPA receptors decreased, after 4 weeks of chronic hypoxia exposure. Concomitantly, apoptotic neuronal cell death in the hippocampus and frontal cortex was significantly increased, along with levels of oxidative stress, whereas innate ability to inhibit free radicals decreased. Moreover, after 8 weeks of hypoxia exposure, learning, memory, and space exploration abilities were significantly decreased. Notably, after treatment with memantine, apoptotic neuronal cell death, oxidative stress, and free radical levels decreased, and the cognitive function of the animals improved. Present study shows that chronic hypoxia can produce the excitatory toxicity leading to neural injury and cognitive impairment that can be suppressed with memantine treatment by inhibiting excitatory toxicity. Unlabelled Image • The mechanism of cognitive impairment induced by chronic hypoxic exposure is unclear. • Here, we showed that apoptotic neuronal cell death in the hippocampus and frontal cortex was significantly increased, along with levels of oxidative stress, whereas innate ability to inhibit free radicals decreased. • Notably, after treatment with memantine, apoptotic neuronal cell death, oxidative stress, and free radical levels decreased, and the cognitive function of the animals improved. • Together, our study shows that chronic hypobaric hypoxic environmental exposure can produce excitatory toxicity leading to neural injury and cognitive impairment that can be suppressed with memantine treatment by inhibiting excitatory toxicity. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C 3 N 4 ) prepared by traditional methods has various disadvantages, e.g., small specific surface area, low band gap, high photo-generated carriers recombination and low exfoliation efficiency, which limits its practical application. In this study, folded nano-porous graphene-like g-C 3 N 4 (abbreviated as FNPGLCN) was prepared by a simple but quite effective method of calcining urea in water. The effects of calcination temperature on crystal structure, energy band and microstructure of g-C 3 N 4 were investigated. The photocatalytic activity for methylene blue (MB) degradation under visible-light was evaluated. The results revealed that the FNPGLCN had higher specific surface area (197 m 2 /g) and larger band gap (2.87 eV) than bulk g-C 3 N 4 . With calcination temperature rising from 450 to 500 °C, the pore size and specific surface area of FNPGLCN increased. However, the pore structure almost disappeared and the thickness of g-C 3 N 4 became thinner at 550 °C. Compared with bulk g-C 3 N 4 , the photocatalytic degradation rate of FNPGLCN for MB increased from 0.131 to 1.298 h −1 . The significant enhancement of visible photocatalytic activity was mainly attributed to folded nano-porous structure, which simultaneously improved visible-light absorption range and strength, and enlarged the band gap and specific surface area of g-C 3 N 4 . [ABSTRACT FROM AUTHOR]

In this study, a novel low-Pt core-shell catalyst is successfully prepared by depositing ultrathin Pt layer on the carbon nanotubes supported titanium nitride nanoparticles (TiN@Pt/CNTs) via a facile pulse electrochemical deposition approach. The catalyst is characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), High-angle annular dark field (HAADF) and energy-dispersive spectrometer (EDS) elemental mapping, X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. The results confirm the core-shell structure of the prepared TiN@Pt/CNTs catalyst. More importantly, the catalyst exhibits superb mass activity and durability for the methanol oxidation reaction (MOR) than that of the commercial JM Pt/C catalyst. Later experiments data demonstrate that the activity and stability of the catalyst can be further enhanced via copper doping, which results from the modified electronic structure of the Pt atoms and the synergistic effects of the core-shell structure. [ABSTRACT FROM AUTHOR]

Anion exchange membrane fuel cells (AEMFCs) have drawn great attention since the alkaline condition enables the use of non-platinum catalysts. Nevertheless, the lack of alkali-stable and highly conductive anion exchange membranes (AEMs) impedes the development of AEMFCs. Herein, a series of novel quaternized Tröger's base polymer AEMs are prepared via acid-promoted condensation reaction and Menshutkin reaction. It is found that QTBPCE-2.5 AEM demonstrates the highest hydroxide conductivity of 39.0 mS cm−1 at 30 °C, and this value is higher than that of commercialized Tokuyama AHA. The introduction of intrinsic microporosity into the polymer matrix, which is favorable to the rapid ion conduction, may account for the high conductivity. Furthermore, the loss of ionic exchange capacity and conductivity of QTBPCE-2.5 are both less than 10% after the stability test (1 M KOH, 80 °C, 192 h). The introduction of electron-donating crown ether is responsible for good alkaline stability. The present result shows that the as-designed AEMs have the potential for the applications in AEMFCs. Image 1 • Novel Tröger's base polymer AEMs were prepared. • The Tröger's base structure facilitated rapid ion conduction. • The highest conductivity of 91.4 mS cm−1 at 80 °C was obtained. • The crown ether unit improved the chemical stability of the cations. • High retention rate of IEC was achieved after stability test. [ABSTRACT FROM AUTHOR]