Search Results (323)

Surface and sub-surface atomic configurations are critical for catalysis as they host the active sites governing electrochemical processes. This study employs density functional theory (DFT) calculations and Monte Carlo simulations combined with the cluster-expansion approach to investigate atom distribution and Pt segregation in Pt-Fe alloys across varying Pt/Fe ratios. Our simulations reveal a strong tendency for Pt atoms to segregate to the surface layer while Fe atoms enrich the sub-surface region. Crucially, the calculations predict the stability of a periodic Pt₂Fe alloy surface model, characterized by specific defect structures, at low platinum content and low annealing temperatures. Electronic structure analysis indicates that forming this Pt₂Fe surface alloy lowers the d-band center of Pt atoms, weakening CO adsorption and thereby enhancing resistance to CO poisoning. Although defect-induced strains can modulate the d-band center, crystal orbital Hamilton population (COHP) analysis confirms that such strains generally strengthen Pt-CO interactions. Therefore, the theoretical design of Pt₂Fe alloy surfaces and controlling defect density are predicted to be effective strategies for enhancing catalyst resistance to CO poisoning. This work highlights the advantages of periodic Pt₂Fe surface models for anti-CO poisoning and provides computational guidance for designing efficient Pt-based electrocatalysts. Full article

In Gram-negative bacteria, lipopolysaccharides (LPSs, also known as endotoxin) can induce extensive immune responses that will enable victims to produce severe septic shock syndrome. Because of the high mortality of sepsis in the face of standard treatment, advance detoxification schemes are urgently needed in clinics. Herein, we described a supramolecular detoxification approach via direct host–guest complexation by a giant macrocycle. Cationic pentaphen[3]arene (CPP3) bearing multiple quaternary ammonium groups was screened as a candidate antidote. CPP3 exhibited robust binding affinity toward LPS with an association constant of (4.79 ± 0.29) × 10⁸ M⁻¹. Co-dosing with an equivalent amount of CPP3 has been demonstrated to decrease LPS-induced cytotoxicity on a cellular level through inhibiting ROS generation and proinflammatory cytokine expression. In vivo experiments have further proved that post-treatment by CPP3 could significantly improve the survival rate of LPS-poisoned mice from 0 to 100% over a period of 3 days, and inflammatory abnormalities and tissue damage were also alleviated. Full article

The methanol oxidation reaction (MOR) of direct methanol fuel cells (DMFCs) is limited by the slow kinetic process and high reaction energy barrier, significantly restricting the commercial application of DMFCs. Therefore, developing MOR catalysts with high activity and stability is very important. In this paper, oxygen-functionalised activated carbon (FAC) with controllable oxygen-containing functional groups was prepared by adjusting the volume ratio of H₂SO₃/HNO₃ mixed acid, and Pd/AC and Pd/FAC catalysts were synthesised via the hydrazine hydrate reduction method. A series of characterisation techniques and electrochemical performance tests were used to study the catalyst. The results showed that when V(H₂SO₃):V(HNO₃) = 2:3, more defects were generated on the surface of the AC, and more oxygen-containing functional groups represented by C=O and C–OH were attached to the surface of the support, which increased the anchor sites of Pd and improved the dispersion of Pd nanoparticles (Pd NPs) on the support. At the same time, the mass–specific activity of Pd/FAC for MOR was 2320 mA·mg_Pd, which is 1.5 times that of Pd/AC, and the stability was also improved to a certain extent. In situ infrared spectroscopy further confirmed that oxygen functionalisation treatment promoted the formation and transformation of *COOH intermediates, accelerated the transformation of CO_L into CO_B, reduced the poisoning of CO_ads species adsorbed to the catalyst, optimised the reaction path and improved the catalytic kinetic performance. Full article

Vibrio parahaemolyticus is the leading cause of bacterial diarrhea in humans from shellfish consumption. In Thailand, blood clam is a popular shellfish, but homemade cooking often results in insufficient heating. Therefore, consumers may suffer from food poisoning due to Vibrio infection. This study aimed to determine the effect of chitooligosaccharide conjugated with epigallocatechin gallate (COS-EGCG) at different concentrations (200 and 400 ppm) combined with high-voltage atmospheric cold plasma (HVACP) on inhibiting V. parahaemolyticus in vitro and in challenged blood clam meat. Firstly, HVACP conditions were optimized for gas composition and treatment time (20 and 60 s); a 70% Ar and 30% O₂ gas mixture resulted in the highest ozone formation and a treatment time of 60 s was used for further study. COS-EGCG conjugate at 400 ppm with HVACP (ACP-CE400) completely killed V. parahaemolyticus after incubation at 37 °C for 6 h. Furthermore, an antibacterial ability of ACP-CE400 treatment against bacterial cells was advocated due to the increased cell membrane damage, permeability, and leakage of proteins and nucleic acids. Scanning electron microscopy (SEM) showed cell elongation and pore formation, while confocal microscopy revealed disrupted biofilm formation. Additionally, the shelf life of challenged blood clam meat treated with ACP-CE400 was extended to nine days. SEM analysis revealed damaged bacterial cells on the meat surface after ACP-CE400 treatment, indicating the antibacterial activity of the combined treatment. Thus, HVACP combined with COS-EGCG conjugate, especially at a highest concentration (400 ppm), effectively inhibited microbial growth and extended the shelf life of contaminated blood clam meat. Full article

Plant–endophyte symbioses are widespread in grasslands. While symbiotic interactions often provide hosts with major fitness enhancements, the role of the endophyte Alternaria oxytropis, which produces swainsonine in locoweeds (Oxytropis and Astragalus spp.), remains enigmatic. We compared endophyte-infected (E+) and endophyte-free (E−) plants of three main Chinese locoweed species (O. kansuensis, O. glabra, and O. ochrocephala) under controlled conditions, and analyzed environmental factors at locoweed poisoning hotspots for herbivores. The results demonstrated significant species-specific effects: E+ plants of O. glabra and O. ochrocephala exhibited 26–39% reductions in biomass, net photosynthetic rate, and stomatal conductance, with elevated CO₂ levels, while O. kansuensis showed no measurable impacts. Swainsonine concentrations were 16–20 times higher in E+ plants (122.6–151.7 mg/kg) than in E− plants. Geospatial analysis revealed that poisoning hotspots for herbivores consistently occurred in regions with extreme winter conditions (minimum temperatures ≤ −17 °C and precipitation ≤ 1 mm during the driest month), suggesting context-dependent benefits under abiotic stress. These findings suggest that the ecological role of A. oxytropis may vary depending on both host species and environmental context, highlighting a trade-off between growth costs and potential stress tolerance conferred by A. oxytropis. The study underscores the need for field validation to elucidate the adaptive mechanisms maintaining this symbiosis in harsh environments. Full article

In this study, density functional theory (DFT) was used to analyze the processes that govern the interactions among triethylaluminum (TEAL), the Ziegler–Natta (ZN) catalyst, and the inhibitory compounds dimethylamine (DMA) and diethylamine (DEA) during olefin polymerization. The structural and charge characteristics of these inhibitors were examined through steric maps and DFT calculations. Combined DFT calculations (D3-B3LYP/6-311++G(d,p)) and IR spectroscopic analysis show that the most efficient way to deactivate the ZN catalyst is via the initial formation of the TEAL·DMA complex. This step has a kinetic barrier of only 27 kcal mol⁻¹ and a negative ΔG, in stark contrast to the >120 kcal mol⁻¹ required to form TEAL·DEA. Once generated, TEAL·DMA adsorbs onto the TiCl₄/MgCl₂ cluster with adsorption energies of −22.9 kcal mol⁻¹ in the gas phase and −25.4 kcal mol⁻¹ in n-hexane (SMD model), values 5–10 kcal mol⁻¹ more favorable than those for TEAL·DEA. This explains why, although dimethylamine is present at only 140 ppm, its impact on productivity (−19.6%) is practically identical to that produced by 170 ppm of diethylamine (−20%). The persistence of the ν(Al–N) band at ~615 cm⁻¹, along with a >30% decrease in the Al–C/Ti–C bands between 500 and 900 cm⁻¹, the downward shift of the N–H stretch from ~3300 to 3200 cm⁻¹, and the +15 cm⁻¹ increase in ν(C–N) confirm Al←N coordination and blockage of alkyl transfer, establishing the TEAL·DMA → ZN pathway as the dominant catalytic poisoning mechanism. Full article

Proton exchange membrane fuel cells (PEMFCs) have been widely studied as an efficient and environmentally friendly energy conversion technology in recent years. However, the high cost, easy poisoning and complex synthesis methods of noble metal catalysts have hindered their commercialization. Therefore, in this paper, a non-noble metal composite catalyst CuFeCo/C for the oxygen reduction reaction (ORR) was prepared by using a facile liquid-phase reduction method. The ORR kinetic performance of CuFeCo/C was evaluated by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and rotating ring-disk electrode (RRDE) tests. The results show that the oxygen reduction peak of CuFeCo/C appears at about 0.64 V, the half-wave potential is about 0.73 V, the limiting current density is about −16.51 A·m⁻², and the Tafel slope is about −0.08. The 10,800 s chronoamperometry test shows that the catalyst has a very good long-term cycle stability. This indicates that the CuFeCo/C composite catalyst has strong stability, good conductivity and ORR catalytic activity under alkaline conditions, which can promote the large-scale commercial application of PEMFCs. Full article

Background:Envenomation by poisonous creatures is a major global cause of mortality. Its concomitant impact on the postmortem corpse decomposition and associated insect succession pattern is still poorly understood. Purpose of the study: This study comparatively investigates the impact of envenomization with the venoms of the snake Walterinnesia aegyptia L. versus the scorpion, Androctonus crassicauda L., on rabbit corpse decomposition and beetle succession. Methods: Three groups of rabbits (five animals each) were injected with the snake venom, the scorpion venom, or 0.9% saline (control) prior to euthanasia with CO₂. The corpse decomposition stages and beetle succession were monitored over 11 days. Results: Four stages of decomposition with venom-dependent duration variation were observed. The scorpion-envenomized corpses showed a longer decay stage and a delayed dry stage. A total of 1094 beetles belonging to 27 species of 14 families were reported. Histeridae, Dermestidae, Scarabaeidae, and Tenebrionidae were the most diversified and prevalent families. Chrysomelidae, Elateridae, Hybosoridae, and Ptinidae were incidentally attracted to control corpses, while Nitidulidae and Zopheridae were only found on control and snake-envenomized ones. Four species belonging to the families Anthicidae, Histeridae, Scarabaeidae, and Tenebrionidae were predominant on all corpses. Four species belonging to the families Chrysomelidae, Curculionidae, Elateridae, and Hybosoridae were distinctively associated with the control corpses. Conclusions: These findings provided evidence that envenomation impacted the decomposition process and beetle succession in a venom-dependent manner, which could be significant for forensic investigations. Full article

Evaluating the bioaccessibility and health risks of seafood is extremely important because, although it is a significant source of vital minerals, it may also contain potentially toxic elements. This study aimed to determine the content of metals and minerals in different seafood species before and after thermal processing. Also, given the risk of overestimating the actual final concentration available in the body, a study was carried out to determine the bioaccessibility of these elements by simulating the digestion process in the gastrointestinal tract. Assessment of the potential toxic effects on consumer health in terms of exposure to heavy metals was carried out through risk analysis by Estimated Daily Intake, Hazard Index, and Cancer Risk parameters. Three bivalve mollusks, one gastropod mollusk, four cephalopod mollusks, and one crustacean species were analyzed in terms of minerals (P, S, K, Ca, and Se) and heavy metals (Cd, Pb, Ni, Cr, Fe, Zn, Co, Mn, and As) content. The lead (Pb) concentration recorded the strongest bioaccessibility increase, even reaching 100% in P. vannamei. Generally, the bioaccessibility of all metalloids dropped below 100%, which suggests that only a part of the amount of metal in the initially ingested sample can be absorbed by the human organism. Potassium and sulfur registered the greatest value, up to 23% for minerals’ bioaccessibility in the same samples. The highest intake rate of metals occurred after the consumption of M. gigas, which registered the highest Estimated Daily Intake for Cr (chromium) (0.321 mg kg⁻¹ d⁻¹), Cu (copper) (10.15 mg kg⁻¹ d⁻¹), and Zn (zinc) (12.67 mg kg⁻¹ d⁻¹). The Hazard Index values indicated no significant risk of poisoning. All calculated Cancer Risk scores remained below the acceptable threshold. Moreover, the Pearson coefficient revealed a positive correlation between the Hazard Index and the most abundant elements in the samples, Cr, Zn, and Cu. This study could provide a framework for evaluating both the nutritional benefits and toxicological concerns of seafood intake in public health applications. Full article

The gas adsorption and sensing properties of a transition metal oxide (TMO)-ZnO heterojunction-based sensor for H₂, CO, and C₂H₄ are analyzed. It is found that CuO, Ag₂O, and Cu₂O stably composite onto the surface of ZnO by forming heterojunctions, which helps to improve the gas sensing and selectivity of the sensor. The adsorption results show that CuO-ZnO shows physical adsorption for H₂ and good gas sensing performance for CO and C₂H₄, while Ag₂O-ZnO and Cu₂O-ZnO have significant responses for H₂, CO, and C₂H₄. In addition, the introduction of the TMO-ZnO heterojunction structure can effectively avoid the sensor poisoning phenomenon, as the gas adsorption process does not destroy the original geometric configuration of the heterojunction. This study lays a theoretical foundation for preparing TMO-ZnO heterojunction-based sensors for transformer defect detection and energy efficiency analysis. Full article

Direct methanol fuel cells (DMFCs) represent a promising pathway for energy conversion, yet their reliance on platinum-group metal (PGM)-based anode catalysts poses critical sustainability challenges, which stem from finite mineral reserves, environmentally detrimental extraction processes, and prohibitive lifecycle costs. Current anode catalysts for DMFCs are dominated by platinum materials; therefore, this review systematically evaluates the following three emerging eco-efficient design paradigms using platinum materials as a starting point: (1) the atomic-level optimization of low-Pt alloy surfaces to maximize catalytic efficiency per metal atom, (2) Earth-abundant transition metal compounds (e.g., nitrides and sulfides) and coordination-tunable metal–organic frameworks as viable PGM-free alternatives, and (3) mechanically robust carbon architectures with engineered topological defects that enhance catalyst stability through covalent metal–carbon interactions. Through comparative analysis with pure Pt benchmarks, we critically examine how these strategic material innovations collectively mitigate CO intermediate poisoning risks and improve electrochemical durability. Such fundamental advances in catalyst design not only address immediate technical barriers, but also establish essential material foundations for the development of DMFC technologies compatible with circular economy frameworks and United Nations Sustainable Development Goal 7 targets. Full article

Titanium (Ti) and its alloys have attracted more interest, as they are widely employed as biomaterials due to their great biocompatibility, excellent strength ratio, and lightweight. However, corrosion occurs slowly due to an electrochemical reaction once the Ti material has been placed in the human body, contributing to infection and failure of implants in medical applications. Thus, the corrosion phenomenon has caused great concern in the biomedical field. It is desirable to make the surface modification to provide better corrosion resistance. The fabrication techniques of the coatings fabricated onto Ti and/or Ti alloy surfaces have been reported, including sol–gel, annealing, plasma spraying, plasma immersion ion implantation, physical vapor deposition, chemical vapor deposition, anodization, and micro-arc oxidation. This review first describes the corrosion types, including localized corrosion (both pitting and crevice corrosion), galvanic corrosion, selective leaching, stress corrosion cracking (SCC), corrosion fatigue (CF), and fretting corrosion. In the second part, the effects of corrosion on the human body were discussed, and the primary cause for clinical failure and allergies has been identified as the excessive release of poisonous and dangerous metal ions (Co, Ni, and Ti) from corroded implants into bodily fluids. The inclusion and exclusion criteria during the selection of literature are described in the third section. In the last section, we emphasized the current research progress of Ti alloy (particularly Ti6Al4V alloy) coatings in biomaterials for medical applications involving dental, orthopedic, and cardiovascular implants for anticorrosive applications. However, there are also several problems to explore and address in future studies, such as the release of excessive metal ions, etc. This review will draw attention to both researchers and clinicians, which could help to increase the coatings fabricated onto Ti and/or Ti alloy surfaces for anticorrosive applications in biomaterials for medical applications. Full article

Background: Hyperbaric oxygen therapy (HBOT) is the standard treatment for moderate to severe carbon monoxide (CO) poisoning, but middle ear barotrauma (MEB) remains a common complication. This study identified risk factors associated with MEB in patients undergoing monoplace HBOT. Methods: This retrospective cohort study included patients treated for CO poisoning with monoplace HBOT at a tertiary academic hospital between May 2021 and December 2023. MEB severity was assessed before and after treatment using video otoscopy and graded according to the modified O’Neill Grading System. Results: MEB occurred predominantly at lower severity grades according to the O’Neill scale. In univariate analysis, significant risk factors for MEB included altered mental status at presentation (OR: 3.16, 95% CI: 1.35–7.40, p = 0.008), serum albumin > 4.3 g/dL (OR: 0.22, 95% CI: 0.10–0.65, p = 0.004), and magnesium levels (OR: 0.21, 95% CI: 0.05–0.98, p = 0.046). Multivariate analysis confirmed altered mental status (OR: 3.16, 95% CI: 1.05–9.52, p = 0.041), albumin > 4.3 g/dL (OR: 0.26, 95% CI: 0.10–0.65, p = 0.004), and magnesium level (OR: 0.21, 95% CI: 0.05–0.88, p = 0.033) as independent predictors of MEB. Patients with higher albumin and magnesium levels showed lower risk. Conclusions: Altered mental status, lower albumin, and lower magnesium levels predicted middle ear barotrauma in patients undergoing monoplace HBOT for CO poisoning. These findings highlight the importance of careful pre-treatment evaluation and close monitoring during therapy to reduce the incidence of MEB. Full article

Carbon monoxide (CO) is an important air pollutant generated from the incomplete combustion of fossil fuels, particularly in industrial processes such as iron and steel smelting, power generation, and waste incineration, posing environmental challenges that demand effective removal strategies. Recent advances in noble metal catalysts for catalytic oxidation of CO, particularly Pt-, Pd-, and Rh-based systems, have been extensively studied. However, there is still a lack of systematic review on noble metal-based catalytic oxidation of CO, especially regarding the effects of different active components of the catalysts and the mechanism of sulfur resistance. Based on extensive research and literature findings, this study comprehensively concluded the advances in noble metal-based catalytic oxidation of CO. The effects of preparation methods, supports, and physicochemical properties on the catalytic performance of CO were explored. In addition, the mechanism of the catalytic oxidation of CO were further summarized. Furthermore, given the prevalence of SO₂ in the flue gas, the mechanism of sulfur poisoning deactivation of catalysts and the anti-sulfur strategies were further reviewed. Exploration of new supporting materials, catalyst surface reconstruction, doping modification, and other catalyst design strategies demonstrate potential in improving sulfur resistance and catalytic efficiency. This study provides valuable insights into the design and optimization of noble metal-based catalysts for the catalytic oxidation of CO. Full article

The challenging problem of chlorine “poisoning” SnO₂ for poorly recoverable detection of dichloromethane has been solved in this work. The materials synthesized by Ni or/and Mo doping SnO₂ were spread onto the micro-hotplates (<1 mm³) to fabricate the MEMS sensors with a low power consumption (<45 mW). The sensor based on Mo·Ni co-doped SnO₂ is evidenced to have the best sensing performance of significant response and recoverability to dichloromethane between 0.07 and 100 ppm at the optimized temperature of 310 °C, in comparison with other sensors in this work and the literature. It can be attributed to a synergetic effect of Mo·Ni co-doping into SnO₂ as being supported by characterization of geometrical and electronic structures. The sensing mechanism of dichloromethane on the material is investigated. In situ infrared spectroscopy (IR) peaks identify that the corresponding adsorbed species are too strong to desorb, although it has demonstrated a good recoverability of the material. A probable reason is the formation rates of the strongly adsorbed species are much slower than those of the weakly adsorbed species, which are difficult to form significant IR peaks but easy to desorb, thus enabling the material to recover. Theoretical analysis suggests that the response process is kinetically determined by molecular transport onto the surface due to the free convection from the concentration gradient during the redox reaction, and the output steady voltage thermodynamically follows the equation only formally identical to the Langmuir–Freundlich equation for physisorption but is newly derived from statistical mechanics. Full article