ABSTRACT
Improving the hydroxide conductivity and dimensional stability of anion exchange membranes (AEMs) while retaining their high alkaline stability is necessary to realize the commercialization of AEM water electrolysis (AEMWE). A strategy for improving the hydroxide conductivity and dimensional stability of AEMs by inserting fluorine atoms in the core structure of the backbone is reported, which not only reduces the glass transition temperature of the polymer due to steric strain, but also induces distinct phase separation by inducing polarity discrimination to facilitate the formation of ion transport channels. The resulting PFPFTP-QA AEM with fluorine into the core structure shows high hydroxide conductivity (>159 mS cm-1 at 80 °C), favorable dimensional stability (>25% at 80 °C), and excellent alkaline stability for 1000 h in 2 m KOH solution at 80 °C. Moreover, the PFPFTP-QA is used to construct an AEMWE cell with a platinum group metal (PGM)-free NiFe anode, which exhibits the current density of 6.86 A cm-2 at 1.9 V at 80 °C, the highest performance in Pt/C cathode and PGM-free anode reports so far and operates stably for over 100 h at a constant current of 0.5 A cm-2.
ABSTRACT
Designing low-cost hybrid electrocatalysts for hydrogen production is of significant importance. Recently, MXene-based materials are being increasingly employed in energy storage devices owing to their layered structure and high electrical conductivity. In this study, we propose a facile hydrothermal strategy for producing WS2/Ti3C2 nanosheets that function as electrocatalysts in the hydrogen evolution reaction (HER). WS2 provides a high surface area and active sites for electrocatalytic activity, whereas MXene Ti3C2 facilitates charge transfer. As a result, the synthesized WS2/Ti3C2 offers an increased surface area and exhibits an enhanced electrocatalytic activity in acidic media. The WS2/Ti3C2 (10%) catalyst exhibited a low onset potential of -150 mV versus RHE for the HER and a low Tafel slope of â¼62 mV dec-1. Moreover, WS2/Ti3C2 (10%) exhibited a double-layer capacitance of 1.2 mF/cm-2, which is 3 and 6 times greater than those of bare WS2 and Ti3C2, respectively. This catalyst also maintained a steady catalytic activity for the HER for over 1000 cycles.
ABSTRACT
Efficient alkaline hydrogen evolution electrodes must be used for hydrogen production in anion exchange membrane water electrolyzers (AEMWEs). Therefore, we fabricated a NiMnS catalyst with a Mn-rich surface, which was self-supported on Ti paper through one-step electrodeposition. Mn doping endowed the catalyst with a unique hollow morphology and lattice-distorted structure. Consequently, the NiMnS/Ti electrode exhibited a large number of exposed electrochemical surfaces and effective active sites and a high hydrogen evolution reaction (HER) activity. Specifically, in half-cell measurements, the NiMnS/Ti electrode exhibited an overpotential of 65 mV at 10 mA cm-2, which was lower than that of NiS/Ti (102 mV) and indicated its superior HER activity. When the proposed cathode was applied in an AEMWE single cell, the device achieved a high current density of up to 0.9 A cm-2 at a cell potential of 2.0 V.
ABSTRACT
Low-temperature standard NH3-SCR over copper-exchanged zeolite catalysts occurs on NH3-solvated Cu-ion active sites in a quasi-homogeneous manner. As key kinetically relevant reaction steps, the reaction intermediate CuII(NH3)4 ion hydrolyzes to CuII(OH)(NH3)3 ion to gain redox activity. The CuII(OH)(NH3)3 ion also transfers between neighboring zeolite cages to form highly reactive reaction intermediates. Via operando electron paramagnetic resonance spectroscopy and SCR kinetic measurements and density functional theory calculations, we demonstrate here that such kinetically relevant steps become energetically more difficult with lower support Brønsted acid strength and density. Consequently, Cu/LTA displays lower Cu atomic efficiency than Cu/CHA and Cu/AEI, which can also be rationalized by considering differences in their support topology. By carrying out hydrothermal aging to eliminate support Brønsted acid sites, both CuII(NH3)4 ion hydrolysis and CuII(OH)(NH3)3 ion migration are hindered, leading to a marked decrease in Cu atomic efficiency for all catalysts.
ABSTRACT
PURPOSE: Excessive exercise causes various gastric dysfunction. Gastritis is common among athletes who perform high-intensity training. Gastritis is a digestive disease involving mucosal damage caused by inflammatory reactions and oxidative stress. In this study, the effects of a complex natural extract on gastric mucosal damage and the expression of inflammatory factors were evaluated in an animal model of alcohol-induced gastritis. METHODS: A mixed herbal medicine (Ma-al-gan; MAG) was prepared with four natural products (Curcumae longae Rhizoma, Schisandrae chinensis Fructus, Artemisiae scopariae herba, and Gardeniae Fructus) identified by a systemic analysis using the Traditional Chinese Medicine Systems Pharmacology platform. The effects of MAG on alcohol-induced gastric damage were evaluated. RESULTS: MAG (10-100 µg/mL) significantly reduced the mRNA and protein levels of inducible nitric oxide synthase and cyclooxygenase-2 in lipopolysaccharide-stimulated RAW264.7 cells. MAG (500 mg/kg/d) effectively prevented alcohol-induced gastric mucosal injury in vivo. CONCLUSION: MAG regulates inflammatory signals and oxidative stress and is a potential herbal medicine for gastric disorders.
ABSTRACT
For an anion exchange membrane water electrolyzer (AEMWE), exploring bifunctional electrodes with low cost and high efficiency is a crucial task for future renewable energy systems. Herein, we report a simple method to fabricate cobalt iron oxyhydroxide (CozFe1-zOxHy) bifunctional electrodes for AEMWEs. The bifunctional electrodes were prepared via one-pot electrodeposition on Ti paper (TP). By adjusting the electrodeposition conditions, the morphology and composition of CozFe1-zOxHy/TP could be controlled. The Co65Fe35OxHy/TP electrode demonstrated the highest activity for overall water electrolysis owing to the maximized synergy effect between Co and Fe. The bifunctional activities of Co65Fe35OxHy/TP were well retained at -50 and 50 mA cm-2 for 12 h. Co65Fe35OxHy/TP, which shows the highest bifunctional activity, was employed in an AEMWE single cell as the anode and cathode. The AEMWE single cell employing Co65Fe35OxHy/TP showed a current density of 0.605 A cm-2 at a cell voltage of 2.0 Vcell. The calculated energy efficiency of the single cell is 55.7% at 2.0 A cm-2, which is comparable with those of the state-of-the-art AEMWE single cells with bifunctional electrodes. Furthermore, the cell voltage of the single cell with Co65Fe35OxHy/TP showed negligible degradation for 50 h at 0.6 A cm-2.
ABSTRACT
Human vision is mediated by the retina, one of the most critical tissues in the central nervous system. Glaucoma is a complex retinal disease attributed to environmental, genetic, and stochastic factors, all of which contribute to its pathogenesis. Historically, glaucoma had been thought of primarily as a disease of the elderly; however, it is now becoming more problematic as the incidence rate increases among young individuals. In recent years, excessive light exposure has been suggested as contributing to the rise in glaucoma among the younger generation. Blue light induces mitochondrial apoptosis in retinal ganglion cells, causing optic damage; red light increases cytochrome c oxidase activity in the electron transport system, reducing inflammation and increasing antioxidant reactions to promote cell regeneration. In conclusion, the minimization of blue light exposure and the general application of red light treatment strategies are anticipated to show synergistic effects with existing treatments for retinal disease and glaucoma and should be considered a necessary prospect for the future. This review introduces the recent studies that support the relationship between light exposure and the onset of glaucoma and discusses new treatments, such as photobiomodulation therapy.
ABSTRACT
Metal-organic frameworks (MOFs) constitute a class of crystalline porous materials employed in storage and energy conversion applications. MOFs possess characteristics that render them ideal in the preparation of electrocatalysts, and exhibit excellent performance for the hydrogen evolution reaction (HER). Herein, H-Ni/NiO/C catalysts were synthesized from a Ni-based MOF hollow structure via a two-step process involving carbonization and oxidation. Interestingly, the performance of the H-Ni/NiO/C catalyst was superior to those of H-Ni/C, H-NiO/C, and NH-Ni/NiO/C catalysts for the HER. Notably, H-Ni/NiO/C exhibited the best electrocatalytic activity for the HER, with a low overpotential of 87 mV for 10 mA cm-2 and a Tafel slope of 91.7 mV dec-1. The high performance is ascribed to the synergistic effect of the metal/metal oxide and hollow architecture, which is favorable for breaking the H-OH bond, forming hydrogen atoms, and enabling charge transport. These results indicate that the employed approach is promising for fabricating cost-effective catalysts for hydrogen production in alkaline media.
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Environmental problems such as global warming are one of the most prominent global challenges. Researchers are investigating various methods for decreasing CO2 emissions. The CO2 reduction reaction via electrochemical, photochemical, and photoelectrochemical processes has been a popular research topic because the energy it requires can be sourced from renewable sources. The CO2 reduction reaction converts stable CO2 molecules into useful products such as CO, CH4 , C2 H4 , and C2 H5 OH. To obtain economic benefits from these products, it is important to convert them into hydrocarbons above C2 . Numerous investigations have demonstrated the uniqueness of the CC coupling reaction of Cu-based catalysts for the conversion of CO2 into useful hydrocarbons above C2 for electrocatalysis. Herein, the principle of semiconductors for photocatalysis is briefly introduced, followed by a description of the obstacles for C2+ production. This review presents an overview of the mechanism of hydrocarbon formation above C2 , along with advances in the improvement, direction, and comprehension of the CO2 reduction reaction via electrochemical, photochemical, and photoelectrochemical processes.
ABSTRACT
The electrochemical reduction of CO2 to diverse value-added chemicals is a unique, environmentally friendly approach for curbing greenhouse gas emissions while addressing sluggish catalytic activity and low Faradaic efficiency (FE) of electrocatalysts. Here, zeolite-imidazolate-frameworks-8 (ZIF-8) containing various transition metal ions-Ni, Fe, and Cu-at varying concentrations upon doping are fabricated for the electrocatalytic CO2 reduction reaction (CO2 RR) to carbon monoxide (CO) without further processing. Atom coordination environments and theoretical electrocatalytic performance are scrutinized via X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations. Upon optimized Cu doping on ZIF-8, Cu0.5 Zn0.5 /ZIF-8 achieves a high partial current density of 11.57 mA cm-2 and maximum FE for CO of 88.5% at -1.0 V (versus RHE) with a stable catalytic activity over 6 h. Furthermore, the electron-rich sp2 C atom facilitates COOH* promotion after Cu doping of ZIF-8, leading to a local effect between the zinc-nitrogen (Zn-N4 ) and copper-nitrogen (Cu-N4 ) moieties. Additionally, the advanced CO2 RR pathway is illustrated from various perspectives, including the pre-H-covered state under the CO2 RR. The findings expand the pool of efficient metal-organic framework (MOF)-based CO2 RR catalysts, deeming them viable alternatives to conventional catalysts.
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PURPOSE: Exercise helps modify the lipid profile in the body, partly through its impact on sterol regulatory element binding protein-1 (SREBP-1) and peroxisome proliferator-activated receptor-γ (PPAR-γ). Individual differences in response to exercise and genetic variations may influence the response to PA. Therefore, this study explored Rosae multiflorae fructus (RMF) as a supplement candidate that improves exercise capacity and controls non-alcoholic fatty liver disease (NAFLD) by suppressing lipogenesis and controlling lipid peroxidation. METHODS: RMF is a natural herbal medicine used in Dongui Bogam. RMF has antioxidant, anti-inflammatory, and anti-allergic effects. However, the effects of RMF on NAFLD have not yet been investigated. In this study, we examined the effects of RMF in a mouse model of high-fat diet-induced NAFLD. Mouse livers were isolated and analyzed using H&E staining and immunohistochemistry. RESULTS: RMF downregulated lipid peroxidation markers, such as CYP2E1, in the livers of mice with high-fat diet-induced NAFLD. Additionally, the RMF significantly reduced the lipid accumulation-related protein expression of CD36, SREBP-1, and PPAR-γ. CONCLUSION: RMF exerts anti-lipid peroxidation and anti-lipogenic effects in a high-fat diet-induced NAFLD mouse model.
ABSTRACT
Psoriasis is a chronic, immune-mediated inflammatory skin disorder. Rheum palmatum L. is a common traditional medicinal herb with anti-inflammatory and immunomodulatory activities. This study aimed to investigate the anti-psoriatic effects of the ethanolic extract from R. palmatum L. (RPE) and its chemical constituents, as well as the mechanisms underlying their therapeutic significance. An imiquimod (IMQ)-induced psoriasis-like mouse model was used to examine the anti-psoriatic effect of RPE in vivo. Network pharmacological analysis was performed to investigate the potential targets and related pathways of the RPE components, including rhein, emodin, chrysophanol, aloe-emodin, and physcion. The anti-inflammatory effects and underlying mechanisms of these components were examined using in vitro models. Topical application of RPE alleviated psoriasis-like symptoms and reduced levels of inflammatory cytokines and proliferation markers in the skin. Network pharmacological analysis revealed that RPE components target 20 genes that are linked to psoriasis-related pathways, such as IL-17, MAPK, and TNF signaling pathways. Among the five components of RPE, rhein and emodin showed inhibitory effects on TNF-α and IL-17 production in EL-4 cells, attenuated the production of CXCL8, CXCL10, CCL20, and MMP9, and reduced proliferation in HaCaT cells. Chrysophanol, aloe-emodin, and physcion were less effective than rhein and emodin in suppressing inflammatory responses and keratinocyte proliferation. The effects of these compounds might occur through the inhibition of the ERK, STAT3, and NF-κB signaling pathways. This study suggested the anti-psoriatic effect of RPE, with rhein and emodin as the main contributors that regulate multiple signaling pathways.
Subject(s)
Emodin , Psoriasis , Rheum , Animals , Mice , Anthraquinones/pharmacology , Anti-Inflammatory Agents/pharmacology , Emodin/pharmacology , Interleukin-17/metabolism , Psoriasis/drug therapy , Psoriasis/chemically induced , Rheum/chemistryABSTRACT
Dedications to achieve the highly efficient metal oxide semiconductor for the photoelectrochemical water splitting system have been persisted to utilize the TiO2 as the promising photoanode material. Herein, we report notable progress for nanostructured TiO2 photoanodes using facile sequential one-pot hydrothermal synthesis and annealing in hydrogen. A photocurrent density of 3.04 mA·cm-2 at 1.23 V vs. reversible hydrogen electrode was achieved in TiO2 nanorod arrays annealed in hydrogen ambient, which is approximately 4.25 times higher than that of pristine TiO2 annealed in ambient air. 79.2% of incident photon-to-current efficiency at 380 nm wavelength demonstrates the prominence of the material at the near-UV spectral range region and 100 h chronoamperometric test exhibits the stability of the photoanode. Detailed studies regarding crystallinity, bandgap, and elemental analysis provide the importance of the optimized annealing condition for the TiO2-based photoanodes. Water contact angle measurement displays the effect of hydrogen annealing on the hydrophilicity of the material. This study clearly demonstrates the marked improvement using the optimized hydrogen annealing, providing the promising methodologies for eco-friendly mass production of water splitting photoelectrodes.
ABSTRACT
A mechanosensitive ion channel, Piezo1 induces non-selective cation flux in response to various mechanical stresses. However, the biological interpretation and underlying mechanisms of cells resulting from Piezo1 activation remain elusive. This study elucidates Piezo1-mediated Ca2+ influx driven by channel activation and cellular behavior using novel Förster Resonance Energy Transfer (FRET)-based biosensors and single-cell imaging analysis. Results reveal that extracellular Ca2+ influx via Piezo1 requires intact caveolin, cholesterol, and cytoskeletal support. Increased cytoplasmic Ca2+ levels enhance PKA, ERK, Rac1, and ROCK activity, which have the potential to promote cancer cell survival and migration. Furthermore, we demonstrate that Piezo1-mediated Ca2+ influx upregulates membrane ruffling, a characteristic feature of cancer cell metastasis, using spatiotemporal image correlation spectroscopy. Thus, our findings provide new insights into the function of Piezo1, suggesting that Piezo1 plays a significant role in the behavior of cancer cells.
ABSTRACT
Molybdenum disulfide (MoS2)-based materials are extensively studied as promising hydrogen evolution reaction (HER) catalysts. In order to bring out the full potential of chalcogenide chemistry, precise control over the active sulfur sites and enhancement of electronic conductivity need to be achieved. This study develops a highly active HER catalyst with an optimized active site-controlled cobalt molybdenum sulfide (CoMo3S13) chalcogel/graphene oxide aerogel heterostructure. The highly active CoMo3S13 chalcogel catalyst was achieved by the synergetic catalytic sites of [Mo3S13]2- and the Mo-S-Co bridge. The optimized GO/CoMo3S13 chalcogel heterostructure catalyst exhibited high catalytic HER performance with an overvoltage of 130 mV, a current density of 10 mA cm-2, a small Tafel slope of 40.1 mV dec-1, and remarkable stability after 12 h of testing. This study presents a successful example of a synergistic heterostructure exploiting both the appealing electrical functionality of GO and catalytically active [Mo3S13]2- sites.
ABSTRACT
PURPOSE: We aimed to investigate the systemic pharmacological analysis of gardenia fructus (GF) and the proof of concepts. We examined the antioxidant and anti-inflammatory effects in high-fat (HF) diet mice. METHODS: The active compounds of GF and the target genes were identified using the Traditional Chinese Medicine Database and Analysis Platform (oral bioavailability ≥ 30%, Caco-2 permeability ≥ -0.4, and drug-likeness ≥ 0.18). The rats were divided into four groups: untreated group, HF group, HF and metformin (17 mg/kg) treated group, and HF and treated with GF (28 mg/kg) for 8 weeks group. Hepatic lesion changes and markers were analyzed using hematoxylin and eosin staining and immunohistochemistry assay. RESULTS: In the systemic analysis, we identified 14 active compounds including A, B, and C. From these 14 compounds, 242 biological target genes were identified. The top 10 Gene Ontology were analyzed using GO-biological process analysis: removal of superoxide radicals, regulation of endothelial cell apoptotic process, and cellular response to lipopolysaccharide. GF extracts in high-fat diet-induced non-alcoholic fatty liver disease (NAFLD) mice models significantly regulated hepatic lesion markers, such as mTOR, 8-Hydroxy- 2'-deoxyguanosine as well as oxidative stress activities, TGF-ß, and phosphorylation of ERK1/2. CONCLUSION: These results suggest that GF, as an exercise supplement, can alleviate NAFLD disease or fatty liver inflammation. Further studies are required to verify the synergistic effect of GF treatment combined with exercise, which is known to alleviate NAFLD and fatty liver inflammation.
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A clear understanding of the acidic properties of bridging Si-OH-Al groups containing crystallographically different oxygen atoms in zeolites is a prerequisite for optimizing their performance as industrial solid catalysts and developing new acid-catalyzed reactions, but presents many challenges. Here, we report the direct observation of yet unrecognized bridging Si-OH-Al groups in the LTA zeolite whose oxygen atoms are crystallographically different from those of already known Brønsted acid sites. We also report that the creation of a crystallographically particular type of bridging OH groups in zeolites and its concentration and acid strength can vary strongly with the content and spatial distribution of framework Al atoms, thus being synthetic in nature, which has been rationalized in terms of the secondary building unit concept.
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Rhynchosia volubilis, a small black bean, has been used as a traditional remedy to treat diseases and maintain health in East Asia, but its cellular effects and molecular mechanisms are not fully understood. The purpose of this study was to investigate the effect of ethanol extract from Rhynchosia volubilis (EERV) on cell survival and to elucidate the biochemical signaling pathways. Our results showed that EERV stimulated the cyclic AMP (cAMP) signal revealed by a fluorescent protein (FP)-based intensiometric sensor. Using a Förster resonance energy transfer (FRET)-based sensor, we further revealed that EERV could activate PKA and ERK signals, which are downstream effectors of cAMP. In addition, we reported that EERV could induce the phosphorylation of CREB, a key signal for cell survival. Thus, our results suggested that EERV protects against apoptosis by activating the cell survival pathway through the cAMP-PKA/ERK-CREB pathway.
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Numerous studies have explored new materials for electrocatalysts, but it is difficult to discover materials that surpass the catalytic activity of current commercially available noble metal electrocatalysts. In contrast to conventional transition metal alloys, high-entropy alloys (HEAs) have immense potential to maximize their catalytic properties because of their high stability and compositional diversity as oxygen evolution reactions (OERs). This work presents medium-entropy alloys (MEAs) as OER electrocatalysts to simultaneously satisfy the requirement of high catalytic activity and long-term stability. The surface of MEA electrocatalyst is tailored to suit the OER via anodizing and cyclic voltammetry activation methods. Optimized electrical properties and hydrophilicity of the surface enable an extremely low overpotential of 187 mV for achieving the current density of 10 mA cm-2 alkaline media. Furthermore, a combined photovoltaic-electrochemical system with MEA electrocatalyst and a perovskite/Si tandem solar cell exhibits a solar-to-hydrogen conversion efficiency of 20.6% for an unassisted hydrogen generation system. These results present a new pathway for designing sustainable high efficiency water splitting cells.
ABSTRACT
Despite its importance for the establishment of a carbon-neutral society, the electrochemical reduction of CO2 to value-added products has not been commercialized yet because of its sluggish kinetics and low selectivity. The present work reports the fabrication of a low-crystalline trimetallic (AuCuIn) CO2 electroreduction catalyst and demonstrates its high performance in a gaseous CO2 electrolyzer. The high Faradaic efficiency (FE) of CO formation observed at a low overpotential in a half-cell test is ascribed to the controlled crystallinity and composition of this catalyst as well as to its faster charge transfer, downshifted d-band center, and low oxophilicity. The gaseous CO2 electrolyzer with the optimal catalyst as the cathode exhibits superior cell performance with a high CO FE and production rate, outperforming state-of-the-art analogs. Thus, the obtained results pave the way to the commercialization of CO2 electrolyzers and promote the establishment of a greener society.