Search Results (512)

Developing highly efficient and stable electrocatalysts from inexpensive and earth-abundant elements represents a significant advancement in overall water splitting (OWS). This study focuses on the synthesis and evaluation of palladium-modified cobalt–phosphorus (PdCoP) and cobalt–iron–phosphorus (PdCoFeP) coatings for use as electrocatalysts in hydrogen evolution (HER), oxygen evolution (OER) and overall water splitting (OWS) in alkaline media. A facile electroless plating method is adopted to deposit the CoP and CoFeP coatings onto a copper surface (Cu sheet), with sodium hypophosphite (NaH₂PO₂) acting as the reducing agent. Pd crystallites were incorporated on CoP and CoFeP coatings using the galvanic displacement method. This study details morphological characterization (using SEM, EDX, and XRD), as well as electrochemical activity testing, for both HER and OER using linear sweep voltammetry (LSV) at different temperatures. The stability of the catalysts for HER was evaluated using chronoamperometry (CA) and chronopotentiometry (CP). The results show that the Pd-modified CoFeP and CoP catalysts exhibited lower overpotentials of 207 and 227 mV, respectively, for HER and 396 mV for OER at a current density of 10 mA cm⁻² compared to the unmodified CoFeP and CoP catalysts. The innovation achieved in this study lies in combining a facile, low-cost deposition method (electroless plating followed by galvanic displacement) with a novel, highly effective ternary composition (PdCoFeP) that exploits synergistic electronic and morphological effects to achieve superior bifunctional performance for alkaline OWS, achieving a low cell voltage of 1.69 V at a current density of 10 mA cm⁻². Overall, this research demonstrates that these synthesized materials are promising candidates for sustainable and economical hydrogen production. Full article

There is a knowledge gap about the effect of pharmaceutical agents on the biodegradation of Mg-based resorbable implants. The present work investigates how three common antibiotics and three anti-inflammatory drugs affect the corrosion of high-purity Mg, with and without ceramic and hybrid ceramic/polymeric coatings, using electrochemical impedance spectroscopy and hydrogen evolution tests. A Ca-P-Si-based ceramic coating is developed using plasma electrolytic oxidation (PEO), after the AC voltage and frequency parameters are optimized. A hybrid coating included a PEO and a poly(ε-caprolactone) (PCL) top layer formed by dip coating. High-purity Mg exhibited an instantaneous onset of corrosion with a corrosion rate of 90 μm/year after 24 h of immersion in a modified α-MEM. A hybrid PEO/PCL coating prevents the onset of corrosion for at least 5 h and reduces the H₂ evolution during the following 90 h by two times by the precipitation of 5–40 μm thick Ca-P surface deposits. Gentamicin, naproxen, streptomycin, ciprofloxacin and paracetamol were found to be corrosion accelerators with respect to bare h.p. Mg, whereas aspirin was found to be an inhibitor. Streptomycin-functionalized PEO/PCL system exhibited an active protection mechanism, triggered upon the release of the coating and substrate cations, associated with the coating defect-blocking action of the insoluble Me(II)-streptomycin chelates. Full article

Background/Objectives: Chronic diseases linked to obesity represent a major global health challenge. Although pharmaceutical treatments show efficacy, their use is often limited by side effects. Methods: This study investigated the anti-obesity effects of acid-processed Citrus reticulata Blanco peels extract (CRBE) prepared through reflux extraction with 50% ethanol, followed by acid treatment using 3 M hydrogen chloride and neutralization. Results: Following acid treatment, the composition of the extract showed a marked increase in the 5-demethylated forms of polymethoxyflavones, particularly 5-demethylnobiletin (31.86 mg/g) and 5-demethyltangeretin (34.68 mg/g), whereas the concentrations of the typical citrus polymethoxyflavones, nobiletin (14.82 mg/g) and tangeretin (10.61 mg/g), decreased. Using 3T3-L1 preadipocytes, CRBE inhibited adipogenesis concentration dependently, substantially decreasing the expression of adipogenic transcription factors and lipid metabolism-related proteins. In ob/ob mice, oral CRBE substantially suppressed body weight gain without affecting food intake, while normalizing liver function indicators and improving serum lipid profiles by reducing total cholesterol, triglycerides, and low-density lipoprotein. Conclusions: Acid-processed CRBE effectively inhibits adipocyte differentiation and exhibits anti-obesity effects in vivo, offering potential as a natural agent for obesity management with minimal side effects. Full article

Oxidative stress plays an important role in the progression of neurodegenerative diseases (NDDs), and N-acetylcysteine (NAC) has gained attention as a potential agent due to its antioxidant capabilities. This study investigated the synergistic neuroprotective effects of combining NAC with non-contact, high-frequency, low-intensity pulsed electric field (H-LIPEF) stimulation on SH-SY5Y human neuronal cells subjected to hydrogen peroxide (H₂O₂)-induced oxidative damage. It was found that after SH-SY5Y cells were pretreated with NAC and exposed to H-LIPEF stimulation, the oxidative stress of cells was reduced in the subsequent treatment with H₂O₂. The results showed that the combined NAC and H-LIPEF treatment significantly improved cell viability and more effectively reduced mitochondrial apoptosis. Mechanistic analyses revealed that the combination substantially decreased levels of superoxide and intracellular H₂O₂, which was associated with enhanced activation of the phosphorylated Akt (p-Akt)/nuclear factor erythroid 2-related factor 2 (Nrf2)/superoxide dismutase type 2 (SOD2) signaling pathway. Furthermore, the treatment reduced the accumulation of 8-oxo-2′-deoxyguanosine triphosphate (8-oxo-dG) accumulation and elevated MutT homolog 1 (MTH1) expression, indicating a protective effect against oxidative DNA damage. These results suggest that H-LIPEF enhances the neuroprotective efficacy of low-dose NAC, highlighting the potential of this combination approach as a new therapeutic strategy for the treatment of NDDs. Full article

Peripheral edema is a pathological condition caused by abnormal fluid accumulation in the interstitial space due to elevated vascular permeability and inflammation. This study evaluated the therapeutic efficacy of Terminalia chebula fruit extract (TCE) in inflammation-induced peripheral edema and clarified its molecular mechanisms. Using hydrogen peroxide (H₂O₂)-stimulated human umbilical vein endothelial cells (HUVECs), TCE was tested for effects on cell viability, inflammatory gene expression, intracellular reactive oxygen species, endothelial barrier integrity, and vascular endothelial growth factor (VEGF)-induced migration. Its influence on nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling was examined. In vivo, TCE was assessed in acetic acid-induced peritoneal vascular permeability and carrageenan-induced paw edema models, followed by histological analysis and serum tumor necrosis factor-α (TNF-α) measurement. TCE restored cell viability (76.2% to 94.8%), reduced TNF, IL6, and PTGS2 mRNA expression, and decreased reactive oxygen species by 27.2%. It enhanced barrier integrity, increased transendothelial electrical resistance, and inhibited VEGF-induced migration. TCE suppressed NF-κB and MAPK activation. In vivo, TCE reduced Evans blue extravasation by 41.6% and paw edema by 67.5%. Histology showed reduced dermal thickening and inflammatory infiltration, and serum TNF-α levels were lowered. TCE attenuates peripheral edema by preserving endothelial barrier function and suppressing inflammatory signaling, supporting its potential as a therapeutic agent for inflammation-associated vascular dysfunction and edema. Full article

Background/Objectives: Oxidative stress is the major cause of retinal pigment epithelial cell death. We used oxidative stress-injured retinal pigment epithelial cells to investigate the protective effects of curcumin, a strong antioxidant, on the Nod-like receptor protein 3 (NLRP3) inflammasome pathway. Methods: To evaluate the effect of curcumin, cell viability was measured with cell counting kit-8 and lactate dehydrogenase assays. Hydrogen peroxide (H₂O₂)-injured ARPE-19 cells were treated with different curcumin concentrations. We performed a wound healing assay and dichlorodihydrofluorescein diacetate staining. Western blotting and immunofluorescence staining were performed to evaluate the changes in inflammasome levels in the ARPE-19 cells. Result: H₂O₂ (300 μM) reduced the viability of ARPE-19 cells. However, treatment with 7.5 μM curcumin enhanced ARPE-19 cell viability and reduced cell toxicity. Curcumin also reduced reactive oxygen species (ROS) levels in the H₂O₂-induced damaged ARPE-19 cells and attenuated the H₂O₂-dependent levels of the NLRP3 inflammasome and its related signaling proteins. Conclusions: Curcumin demonstrated protective effects against oxidative stress in retinal pigment epithelial cells by attenuating the activation of the NLRP3 inflammasome pathway. These findings suggest the therapeutic potential of curcumin as an anti-inflammatory and antioxidant agent for macular degeneration. Full article

Today, hydrogen is already widely regarded as up-and-coming source of energy. It is essential to meet energy needs while reducing environmental pollution, since it has a high energy capacity and does not emit carbon oxide when burned. However, for the widespread application of hydrogen energy, it is necessary to search new technical solutions for both its production and storage. A promising effective and cost-efficient method of hydrogen generation and storage can be the use of solid materials, including nanomaterials in which chemical or physical adsorption of hydrogen occurs. Focusing on the recommendations of the DOE, the search is underway for materials with high gravimetric capacity more than 6.5% wt% and in which sorption and release of hydrogen occurs at temperatures from −20 to +100 °C and normal pressure. This review aims to summarize research on hydrogen generation and storage using silicon nanostructures and silicon composites. Hydrogen generation has been observed in Si nanoparticles, porous Si, and Si nanowires. Regardless of their size and surface chemistry, the silicon nanocrystals interact with water/alcohol solutions, resulting in their complete oxidation, the hydrolysis of water, and the generation of hydrogen. In addition, porous Si nanostructures exhibit a large internal specific surface area covered by SiH_x bonds. A key advantage of porous Si nanostructures is their ability to release molecular hydrogen through the thermal decomposition of SiHx groups or in interaction with water/alkali. The review also covers simulations and theoretical modeling of H₂ generation and storage in silicon nanostructures. Using hydrogen with fuel cells could replace Li-ion batteries in drones and mobile gadgets as more efficient. Finally, some recent applications, including the potential use of Si-based agents as hydrogen sources to address issues associated with new approaches for antioxidative therapy. Hydrogen acts as a powerful antioxidant, specifically targeting harmful ROS such as hydroxyl radicals. Antioxidant therapy using hydrogen (often termed hydrogen medicine) has shown promise in alleviating the pathology of various diseases, including brain ischemia–reperfusion injury, Parkinson’s disease, and hepatitis. Full article

Osteoarthritis (OA) is primarily a degenerative disease triggered by joint inflammation and oxidative stress. While Aster glehni is an edible and traditionally medicinal herb, the beneficial effect of A. glehni on OA progression remains unknown. This study aimed to investigate the effect of A. glehni extract (AGE) and its primary biological compound—3,5-dicaffeoylquinic acid (3,5-DCQA)—on inflammation and oxidative stress in chondrocytes. AGE effectively inhibited the expression of interleukin (IL)-6, cyclooxygenase (COX)-2, matrix metalloproteinase (MMP)-1, and MMP-13 in chondrocytes stimulated by IL-1β for 24 h. In contrast, 3,5-DCQA did not inhibit IL-6, COX-2, and MMP expressions under the same conditions. However, when chondrocytes were stimulated by IL-1β for a short duration (6 h), 3,5-DCQA suppressed IL-6, COX-2, and MMP expressions. The inhibition of IL-6, COX-2, and MMP expressions by AGE was associated with the p38 kinase and nuclear factor-κB signaling pathways, but not ERK and JNK signaling pathways. Furthermore, AGE prevented cell apoptosis and reduced intracellular reactive oxygen species levels in chondrocytes induced by hydrogen peroxide (H₂O₂). AGE restored the decreased superoxide dismutase 1 and catalase mRNA expressions caused by H₂O₂. Collectively, AGE may protect against cartilage deterioration by inhibiting inflammation and oxidative stress, making it a promising therapeutic agent for alleviating OA. Full article

This study used Rosa roxburghii Tratt. crude extract (RR) as a reducing, stabilizing, and modifying agent for the green synthesis of gold nanoparticles (RR-AuNPs) via the one-pot method for the first time and established a novel colorimetric sensor for detecting tiopronin. Initially, RR-AuNPs with a uniform particle size and stable dispersion were prepared using the reducing property of RR. Upon the introduction of tiopronin, the drug binds to the surface of RR-AuNPs through Au-S bonds and hydrogen bonds, inducing a significant aggregation of RR-AuNPs. The absorbance of the RR-AuNP solution exhibited a linear relationship with the tiopronin concentration in the range of 0.17 μM to 16.67 μM (y = 1.9157 − 0.0972x), with a detection limit of 0.19 μM. The colorimetric sensor was successfully applied to detect tiopronin in urine samples. Compared with other detection methods, this approach is simple to operate and has a high sensitivity, a wide linear range, and a low detection limit. Full article

In this study, the use of spent coffee waste as a green precursor of polyphenolic compounds, which are subsequently employed as reducing agents for the synthesis of zero-valent iron nanoparticles (nZVI) aimed at the efficient removal of dyes from aqueous systems, has been investigated. The nanoparticles, generated in situ in the presence of controlled amounts of hydrogen peroxide, were applied in the removal of organic dyes—including methylene blue, methyl orange, and orange G—through a heterogeneous Fenton-like catalytic process. The synthesized nZVI were thoroughly characterized by nitrogen adsorption at 77 K, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and powder X-ray diffraction (XRD). A statistical design of experiments and response surface methodology were employed to evaluate the effect of polyphenol, Fe(III), and H₂O₂ concentrations on dye removal efficiency. Results showed that under optimized conditions, a 100% removal efficiency could be achieved. This work highlights the potential of nZVI synthesized from agro-industrial waste through sustainable routes as an effective solution for water remediation, contributing to circular economy strategies and environmental protection. Full article

In producing docosahexaenoic acid (DHA) with Schizochytrium sp., the production yield of DHA can be effectively increased through using hydrogen peroxide (H₂O₂) and controlling its concentration at the desired level, since H₂O₂ is a common regulatory mediator for lipid accumulation in oleaginous microorganisms. However, when exposed to the environment of oxidative stress induced by the long-term exogenous addition of H₂O₂ over an extended time span, cells’ metabolic activity would be gradually decreased or even stopped, which ultimately results in a limited duration for producing DHA efficiently. In fact, the severe accumulation of ROS cannot be avoided when implementing the normal DHA fermentation batch without the use of exogenous H₂O₂ because of the necessity of supplying a mass of oxygen for cell respiration. Aiming to overcome these issues, a novel periodic feeding strategy for H₂O₂ and p-aminobenzoate was proposed, and the underlying principle of this strategy is that the substantial harm inflicted on cells due to their continuous exposure to the oxidative stress environment can be effectively alleviated through the implementation of a recovery treatment (p-aminobenzoate, reducing agent) subsequent to the environmental stimulus. When using this strategy, it was achieved that, concurrently, activities of the vital enzymes participating in lipid biosynthesis were maintained at their maximum levels and the maintenance coefficient of glucose reduced to its minimum level (0.0034 1/h vs. 0.0027 1/h) by controlling ROS concentration at lower and desired levels, and thus DHA concentration reached the maximum value of 1.49 ± 0.20 g/L, with a 49% increase compared to the control group. Full article

Age-related macular degeneration (AMD) progresses to vision-threatening dry and wet forms, with no effective dry AMD treatments available. The sulfated polysaccharide (GNP, 25.8 kDa) derived from Gelidium crinale exhibits diverse biological activities and represents a potential source of novel therapeutic agents. This study employed a hydrogen peroxide (H₂O₂)-induced oxidative stress and epithelial–mesenchymal transition (EMT) model in retinal pigment epithelial (RPE) cells to investigate GNP’s protective mechanisms against both oxidative damage and EMT. The results demonstrated that GNP effectively suppressed oxidative stress, with the 600 μg/mL dose significantly inhibiting excessive reactive oxygen species (ROS) generation to levels comparable to untreated controls. Concurrently, at concentrations of 200–600 μg/mL, GNP inhibited NF-κB signaling and increased the Bax/Bcl-2 ratio, effectively counteracting H₂O₂-induced oxidative damage and cell apoptosis. Furthermore, in H₂O₂-treated ARPE-19 cells, 600 μg/mL GNP significantly reduced the secretion of N-cadherin (N-cad), Vimentin (Vim), and α-smooth muscle actin (α-SMA), while increasing E-cadherin (E-cad) expression, consequently inhibiting cell migration. Mechanistically, GNP activated the Nrf2/HO-1 pathway, thereby mitigating oxidative stress. These findings suggest that GNP may serve as a potential therapeutic agent for dry AMD. Full article

Epoxidized soybean oil (ESO) is the oxidation product of soybean oil with hydrogen peroxide and either acetic or formic acid obtained by converting the double bonds into epoxy groups, which is non-toxic and of higher chemical reactivity. Oxidized soybean oil (ESO) has gained significant attention as a renewable and environmentally friendly alternative to petroleum-based epoxy resins. Derived from soybean oil through epoxidation of its unsaturated fatty acids, ESO offers a bio-based platform with inherent flexibility, low toxicity, and excellent chemical resistance. When used as a reactive diluent or primary component in epoxy formulations, ESO enhances the sustainability profile of coatings, adhesives, and composite materials. This study explores the mechanical properties of ESO-based epoxy systems, with particular attention to formulation strategies, crosslinking agents, and performance trade-offs compared to conventional epoxies. The incorporation of ESO not only reduces the reliance on fossil resources but also imparts tunable thermal and mechanical properties, making it suitable for a range of industrial and eco-friendly applications. The results underscore the potential of ESO as a viable component in next-generation green materials, contributing to circular economy and low-impact manufacturing. For the application of these materials in pultrusion and FW technologies, the Taguchi method is used to determine the most influential process parameters. Full article

Tooth whitening is increasingly sought in both clinical and home settings, raising concerns about the efficacy and safety of various whitening agents and their delivery systems. This narrative review compares the whitening performance and biocompatibility of active ingredients, including hydrogen peroxide, carbamide peroxide, activated charcoal, sodium bicarbonate, fluoride compounds, and blue covarine, with particular emphasis on the role of polymer-based carriers in formulation strategies. Hydrogen peroxide and carbamide peroxide remain the most effective agents for intrinsic whitening, but are associated with risks of enamel surface alterations, microhardness reduction, and potential cytotoxicity, particularly at higher concentrations. Sodium bicarbonate provides moderate whitening effects through extrinsic stain removal, while fluoride compounds play a supportive role by reducing demineralization and tooth sensitivity, thereby preserving enamel integrity. These properties make them valuable adjuncts or alternatives for patients with high sensitivity risks. Blue covarine offers immediate optical effects without inducing intrinsic color changes, whereas activated charcoal poses risks of enamel abrasion and surface roughness with limited long-term efficacy. Polymer-based carriers such as Carbopol gels, polyvinylpyrrolidone, and hydroxypropyl methylcellulose are incorporated into whitening formulations to improve viscosity, adhesion, and modulate the release of active ingredients. These polymers might help minimize diffusion of bleaching agents into deeper dental tissues, potentially reducing cytotoxic effects, and may improve handling characteristics. However, dedicated studies evaluating the unique advantages of polymers in different whitening systems remain limited. A comprehensive understanding of both the active ingredients and delivery technologies is critical to balancing esthetic outcomes with long-term oral health. From a clinical perspective, polymer-based carriers might contribute to reducing whitening-related tooth sensitivity, improving patient comfort, and providing more predictable treatment outcomes. Continued research is needed to clarify optimal formulations and application protocols, ensuring safer and more effective tooth-whitening practices in both clinical and home-use scenarios. Full article

Hypoxia-induced oxidative stress and inflammation in the brain are critical contributors to neurological disorders. Hydrogen gas has emerged as a therapeutic agent with potent antioxidant and anti-inflammatory properties. In this study, we evaluated the protective effects of hydrogen against acute hypoxia-induced brain injuries in medaka. Fish were exposed to hypoxia and then recovered in water bubbled with air, hydrogen, or ozone. LOX-1 hypoxia probe imaging and HIF-1α immunostaining showed persistent tissue hypoxia in the air and ozone groups, which was significantly reduced by hydrogen treatment. Histological analysis revealed extensive vascular congestion in the midbrain after hypoxia, which was markedly alleviated by hydrogen. TUNEL assay demonstrated that hydrogen suppressed hypoxia-induced neuronal apoptosis. Immunohistochemistry and ELISA showed elevated levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG) and proinflammatory markers (COX-2, IL-6, TNF-α) in the brains of air- and ozone-treated fish; these increases were significantly attenuated by hydrogen. ORAC assay confirmed that hydrogen restored brain antioxidant capacity. Behavioral analysis further demonstrated that hydrogen treatment improved locomotor activity and stabilized respiratory function. These results indicate that hydrogen protects medaka against hypoxia-induced oxidative and inflammatory injuries and may represent a promising therapeutic strategy for hypoxia-related neurological disorders. Full article