Search Results (11,685)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is initiated by the viral spike proteins, which are key structural components that mediate host cell binding and entry and alter downstream signaling through multiple interactions with endothelial surface receptors. Endothelial dysfunction is a central consequence of COVID-19, contributing to vascular inflammation, barrier disruption, thrombosis, and multi-organ injury affecting the pulmonary, cardiovascular, cerebral, and renal systems. Emerging evidence demonstrates that spike protein-mediated effects, independent of productive viral infection, disrupt endothelial homeostasis through angiotensin-converting enzyme 2 (ACE2) dysregulation, integrin engagement, altered calcium signaling, junctional protein remodeling, oxidative stress, and pro-inflammatory and pro-apoptotic pathways. This review is intentionally focused on spike (S) protein-driven mechanisms of endothelial dysfunction; pathogenic vascular effects attributed to other SARS-CoV-2 structural proteins, including the nucleocapsid (N) protein, are beyond the scope of this discussion. In this review, we synthesize current experimental and translational data detailing the molecular mechanisms by which the SARS-CoV-2 spike protein drives endothelial dysfunction across multiple organ systems and discuss potential therapeutic strategies aimed at preserving endothelial integrity in acute COVID-19 and its long-term vascular sequela. Full article

This study presents a first-of-its-kind investigation into retrofitting domestic vessels with a novel hybrid system integrating a Solid Oxide Fuel Cell (SOFC) and an Internal Combustion Engine (ICE). Using a Lake Ferry and an Island Ferry as case studies, three power-sharing scenarios (10–20% SOFC contribution) were examined for cruise and port operations. The results show that increasing the SOFC power share enhances overall system efficiency, reducing daily fuel energy consumption by up to 9% while achieving SOFC efficiencies of 58–60% in port. The design analysis confirms the physical retrofit feasibility for both vessels, with all scenarios occupying 72–92% of available machinery space. However, increasing the SOFC share from 10% to 15–20% raised total system weight by 10–20% and volume by 12–27%. Economically, the system demonstrates strong viability for high-utilization vessels, with Levelized Cost of Energy (LCOE) values of 236–248 EUR/MWh, while the sensitivity analysis highlights the SOFC capital cost as the dominant economic driver. Environmentally, the hybrid system achieves annual CO₂ reductions of 46–51% and NOx reductions of 51–62% compared to conventional diesel systems, with zero NOx emissions in port. The SOFC-ICE hybrid system proves to be a robust transitional pathway for maritime decarbonization, particularly for vessels with significant port-side operating hours. Full article

In industrial combustion processes, high concentrations of propane (C₃H₈) gas are employed. Therefore, developing gas-detecting devices that operate under high concentrations, elevated temperatures, and short response times is crucial. This paper presents the design, simulation, and construction of a novel propane (C₃H₈) gas detector. The design was based on the dynamic electrical response of a gas sensor fabricated with cobalt antimoniate (CoSb₂O₆). The simulation considered the device structure and programming criteria, and the final prototype was constructed according to the sensor response, design parameters, and operating principles. Design, simulation, and fabrication results were in concordance, confirming the correct operation of the detector at high gas concentrations. A mathematical model was derived from the sensor’s electrical response, establishing a resistance value that allowed a two-second response time. This resistance was used to adapt the signal between the gas sensor and the PIC18F2550 microcontroller. Input/output signals, safety criteria, and functionality principles were considered in the programming device. The resulting propane (C₃H₈) gas detector operates at 300 °C, detects high C₃H₈ concentrations, and achieves a 2 s response time, making it ideal for industrial applications where combustion monitoring is essential. Full article

The article presents an extensive review of modern technological solutions for pulverized coal combustion, with emphasis on combustion modifiers and biomass co-firing. It highlights the role of coal in the national energy system and the need for its sustainable use in the context of energy transition. The pulverized coal combustion process is described, along with factors influencing its efficiency, and a classification of modifiers that improve combustion parameters. Both natural and synthetic modifiers are analyzed, including their mechanisms of action, application examples, and catalytic effects. Special attention is given to the synergy between transition metal compounds (Fe, Cu, Mn, Ce) and alkaline earth oxides (Ca, Mg), which enhances energy efficiency, flame stability, and reduces emissions of CO, SO₂, and NO_x. The article also examines biomass-coal co-firing as a technology supporting energy sector decarbonization. Co-firing reduces greenhouse gas emissions and increases the reactivity of fuel blends. The influence of biomass type, its share in the mixture, and processing methods on combustion parameters is discussed. Finally, the paper identifies directions for further technological development, including nanocomposite combustion modifiers and intelligent catalysts integrating sorption and redox functions. These innovations offer promising potential for improving energy efficiency and reducing the environmental impact of coal-fired power generation. Full article

Trichomoniasis is the most prevalent non-viral sexually transmitted infection worldwide and is caused by Trichomonas vaginalis. The development of resistance against the standard treatment, metronidazole, highlights the need for alternative therapeutic approaches. The role of innate immune cells is crucial for understanding trichomoniasis; however, the contribution of monocytes remains poorly characterized. We previously reported that the antimicrobial peptides LL-37 and its derivative KR-20 are trichomonacidal. In other systems, LL-37 displays immunomodulatory effects. Nevertheless, whether these peptides modulate monocyte responses in the presence of T. vaginalis remains unknown, which was the aim of this study. U937 monocytes were co-incubated with LL-37 or KR-20 (3 h), with or without parasite. Monocyte metabolic activity, nitric oxide production, and relative expression of innate immune genes were assessed. LL-37 decreased monocyte metabolic activity and upregulated TNF-α expression (10 and 5 μM, respectively) in parasite-challenged monocytes. Meanwhile, KR-20 (2.5–10 μM) preserved metabolic activity, bound microbial components (LPS), reduced parasite-induced nitric oxide production, and downregulated the expression of IL-8, TNF-α, IL-1β, and COX-2 in infected monocytes. This work provides initial evidence that KR-20 modulates innate immune response in monocytes during T. vaginalis infection, suggesting its potential—yet to be fully validated—as an immunomodulatory candidate for trichomoniasis. Full article

Methanol is a promising alternative marine fuel due to its favorable combustion characteristics and potential to reduce exhaust emissions under increasingly stringent International Maritime Organization (IMO) regulations. This study presents a three-dimensional computational fluid dynamics (CFD) analysis of a four-stroke, medium-speed marine engine operating in methanol–diesel dual-fuel (DF) mode. Simulations were performed using AVL FIRE for a MAN B&W 6H35DF engine, covering the in-cylinder process from intake valve closing to exhaust valve opening. Nine operating cases were investigated, including seven methanol–diesel DF cases with equivalence ratios (Φ) from 0.18 to 0.30, one methane–diesel DF case (Φ = 0.22), and one pure diesel baseline. A power-matched condition (IMEP ≈ 20 bar) enabled consistent comparison among fueling strategies. The results show that methanol–diesel DF operation reduces peak in-cylinder pressure, heat-release rate, turbulent kinetic energy, and wall heat losses compared with diesel operation. At low to moderate Φ, methanol DF combustion significantly suppresses nitric oxide (NO), soot, and carbon monoxide (CO emissions), while carbon dioxide (CO₂) emissions increase with Φ and approach diesel levels under power-matched conditions. These results highlight methanol’s potential as a viable low-carbon fuel for marine engines. Full article

Rice is a vital staple food crop worldwide and also one of the major sources of greenhouse gas (GHG) emissions, generating substantial methane (CH₄) and nitrous oxide (N₂O). As one of the key management practices for rice production, the GHG mitigation potential of water management has attracted extensive attention, whereas its global scalability remains to be further investigated. Based on 15,458 global observations of field experimental data, we employed advanced machine learning methods to quantify the GHGs and soil carbon sequestration of global rice systems around 2020. Furthermore, we identified the optimal spatial distribution of GHG mitigation for five rice water management practices (continuous flooding (CF), flooding–midseason drainage–reflooding (FDF), alternate wetting and drying irrigation (AWD), flooding–midseason drainage–intermittent irrigation (FDI), and rainfed cultivation (RF)) through scenario simulation, under the premise of no yield reduction. The results of machine learning simulation showed that optimizing water management could reduce global rice greenhouse gas emissions by 39.17%, equivalent to 340.46 Mt CO₂ eq, while increasing rice yields by 3.55%. This study provides valuable insights for the optimization of agricultural infrastructure and the realization of agricultural sustainable development. Full article

This study investigated the combined effects of climate change-related salinity extremes and nanoparticle pollution on the seagrass Posidonia oceanica and the macroalga Caulerpa prolifera. Both species were exposed, individually and in co-occurrence, to different salinity regimes (34; 38 and 42 g kg⁻¹) and to the emerging contaminant nano-TiO₂ (0.7 mg L⁻¹, environmentally relevant concentration, and 5.0 mg L⁻¹, high-stress exposure). Biochemical and physiological responses were assessed at baseline (T0) and after 3, 6, and 12 days of exposure, followed by a 12-day recovery phase to evaluate post-stress resilience. This multifactorial design enabled the evaluation of interactive and cumulative effects of salinity shifts associated with climate change and nanoparticle contamination. Results showed that P. oceanica was particularly sensitive to nano-TiO₂ at a concentration of42 g kg⁻¹. Reduced photosynthetic performance was associated with enhanced oxidative stress and limited recovery capacity, suggesting potential long-term impacts on meadow persistence and ecosystem functioning. In contrast, C. prolifera exhibited higher tolerance and recovery efficiency, potentially gaining a competitive advantage under climate-induced environmental variability and increasing the risk of seagrass decline and community shifts in coastal ecosystems. These biochemical markers of early stress do not necessarily reflect direct population effects, particularly in long-lived foundation species such as Posidonia oceanica. Full article

Background: Climate change is a serious threat to global health. The healthcare sector contributes substantially to greenhouse gas (GHG) emissions, with anaesthetic gases being a major source of Scope 1 emissions. We aimed to evaluate the 2024 impact of the Sustainable Anesthesia Project, designed to reduce the environmental footprint of anaesthetic gases by eliminating and/or replacing the most polluting agents (nitrous oxide and desflurane) with more sustainable alternatives (sevoflurane, total intravenous anaesthesia, and regional/local anaesthesia). Methods: We conducted a descriptive analysis of anaesthetic gas consumption in 2023 and 2024, as well as a comparison of emissions in tons of CO₂, the impact on the carbon footprint, and the potential future emissions savings that full implementation of the project would entail. Results: In the first year, nitrous oxide consumption decreased by 64% and desflurane by 63%. Overall anaesthetic-gas emissions fell by 8386 tCO₂e versus 2023, a 54% relative reduction. Furthermore, the contribution of these gases to the total Scope 1 emissions markedly declined from 35.18% in 2023 to 21.22% in 2024. An additional reduction potential of around 4800 tCO₂e was identified for consolidation by 2025 with full implementation. Conclusions: The results observed in this study demonstrate the success of the Sustainable Anesthesia Project, whose strategy represents an extensible and applicable option to other centers and companies in the health sector to reduce their environmental impact. Full article

Background/Objectives: Sulfated polysaccharides from Spirulina platensis have shown various promising biological activities, but their anticancer effects in lung cancer models remain poorly characterized. In this study, sulfated polysaccharide-rich fractions (SPPs) were tested on A549 non-small cell lung cancer (NSCLC) cells to evaluate their cytotoxic, oxidative, and immunomodulatory activity. Methods: The potential of SPPs to interfere with A549 cell viability, to modulate intracellular reactive oxygen species (ROS) levels, to produce pro-inflammatory effects, and to induce apoptosis was evaluated. Co-administration experiments were also performed using Gefitinib, a drug commonly used in NSCLC therapy. Non-cancerous human bronchial epithelial cells (16HBE) were included to assess the ability of SPPs to selectively target tumoral cells. Results: Our findings show that SPPs significantly reduced A549 cell viability in a concentration-dependent manner and increased ROS levels. This effect was associated with apoptotic DNA fragmentation and modulation of apoptosis-related genes, including upregulation of BAX and CASP-9, and downregulation of BCL-2, MTOR, and BIRC5. SPPs also induced a controlled pro-inflammatory response by increasing ACE2, NF-κB1, and CCL2 expression while reducing COX-2 levels. In co-administration experiments with Gefitinib, a cancer drug used to treat NSCLC, enhanced cytotoxic and pro-apoptotic effects were observed. Importantly, at active concentrations (150–250 µg/mL) SPPs were not found to produce cytotoxicity or apoptosis in 16HBE cells. Conclusions: Overall, these findings suggest that SPPs may selectively target NSCLC cells by promoting redox imbalance, apoptosis, and immune response, without affecting healthy cells, supporting their potential as natural adjuvants in lung cancer treatment. Full article

Supercapacitors have attracted significant interest as increased energy storage devices due to their high power density, rapid charge/discharge performance, and long cyclability. In this study, NiO, Co₃O₄, NCO, and NCO/rGO composite electrodes were prepared and evaluated for high-performance supercapacitor applications. The uniform distribution of elements and the effective incorporation of rGO into the composite were confirmed by structural and morphological characterizations. Among the evaluated materials, the NCO/rGO electrode exhibited high electrochemical performance, delivering a specific capacitance of 998 F g⁻¹ in a three-electrode configuration, attributed to the enhanced redox activity of NiCo₂O₄ coupled with the enhanced electrical conductivity of rGO. Additionally, an asymmetric supercapacitor device with activated carbon as the negative electrode and NCO/rGO as the positive electrode showed a power density of 750 W kg⁻¹, an energy density of 29.2 Wh kg⁻¹, and a specific capacitance of 93.7 F g⁻¹. After 5000 charge/discharge cycles, the device maintained 85% of its initial capacitance and a coulombic efficiency of 99%, demonstrating exceptional cyclability. These results highlight the strong potential of the NiCo₂O₄/rGO composite as an advanced electrode material for next-generation energy storage systems. Full article

A numerical simulation is conducted to investigate the interaction and burnout characteristics of mixed coal under O₂/CO₂ atmosphere in a 200 MW tangential firing boiler. Multiple models are utilized to simulate the flow and combustion processes inside the furnace, and a three-dimensional full-furnace model is constructed using an improved Weighted-Sum-of-Gray-Gases (WSGG) model. Using two types of coal and their mixed coal, the combustion of mixed coal under four O₂/CO₂ atmospheres is examined. Results show that there exists a significant interactive effect of promoting ignition and inhibiting burnout between difficult-to-ignite coal and easy-to-ignite coal. Increasing the proportion of easy-to-ignite coal helps improve the ignition performance of mixed coal. With a high proportion of easy-to-ignite coal, the oxygen-grabbing ability is enhanced. Increasing the inlet oxygen concentration can facilitate coal ignition and effectively enhance the burnout rate of difficult-to-ignite coal, mitigating the adverse effects of burnout inhibition. Among five typical oxidant-stream distribution methods, the positive pagoda oxidant-stream distribution can satisfy the combustion requirements of each layer, achieve relatively high burnout rates for difficult-to-ignite coal and mixed coal, and demonstrate the optimal comprehensive combustion performance. The findings can provide valuable references for optimizing oxygen-enriched combustion in boilers, thereby promoting the sustainability of coal-fired power generation. Full article

Direct ethanol fuel cells (DEFCs) have gained considerable attention as promising power sources for sustainable energy conversion due to their high energy density, low toxicity, and renewable ethanol feedstock. However, the sluggish ethanol oxidation reaction (EOR) kinetics and the formation of strongly adsorbed intermediates (e.g., CO*, CH_x*) severely hinder catalytic efficiency and durability. Rhodium (Rh)-based catalysts stand out for their balanced intermediate adsorption, efficient C–C bond cleavage, and superior CO tolerance arising from their unique electronic structure. This review summarizes recent advances in Rh-based EOR catalysts, including monometallic Rh nanostructures, Rh-based alloys, and Rh–support composites. The effects of morphology, alloying, and metal–support interactions on activity, selectivity, and stability are discussed in detail. Strategies for structural and electronic regulation—such as nanoscale design, alloying modulation and interfacial engineering—are highlighted to enhance catalytic performance. Finally, current challenges and future directions are outlined, emphasizing the need for Rh-based catalysts with high activity, selectivity and stability, integrating in situ characterization with theoretical modeling. This work provides insights into the structure–activity relationships of Rh-based catalysts and guidance for designing efficient and durable anode catalysts for practical DEFC applications. Full article

Facet engineering has emerged as a promising approach to tailor the catalytic performance of metal oxides for environmental electrocatalysis. Herein, we synthesized spinel Co₃O₄ nanocrystals with predominantly exposed {110}, {111}, and {112} facets to investigate their facet-dependent electrocatalytic activity toward chlorine-mediated ammonia oxidation. Structural characterization confirmed the successful fabrication of well-defined {110} nanorods, {111} octahedra, and {112} nanoplates. Electrochemical evaluation revealed a distinct activity trend: {110} > {112} > {111}. The Co₃O₄ {110} facet exhibited the lowest chlorine evolution potential, the smallest charge-transfer resistance, and the highest ammonia removal rate, achieving nearly complete oxidation of 75 mg L⁻¹ NH₄⁺-N within 2 h at 15 mA cm⁻². Mechanistic studies demonstrated that free chlorine species (HOCl/OCl⁻), rather than hydroxyl or chlorine radicals, serve as the primary oxidants. XPS and CV analyses further indicated that the superior activity of the {110} facet is attributed to its higher proportion of Co³⁺ sites and greater oxygen vacancy density, which enhance chloride adsorption and facilitate the Co³⁺/Co²⁺ redox cycle critical for the chlorine evolution reaction. This work elucidates the intrinsic structure–activity relationships of Co₃O₄ facets and provides a rational strategy for designing efficient electrocatalysts for electrochemical ammonia removal. Full article

Cadmium (Cd) contamination in agricultural systems poses significant ecotoxicological risks through bioaccumulation in food chains. While lime-based amendments are widely applied for Cd immobilization, mechanistic understanding of bioavailability control pathways remains limited. This study employed a meta-analysis methodology based on 260 datasets from 55 publications to systematically investigate the mechanisms and differences in the effectiveness of calcium hydroxide, calcium carbonate, and calcium oxide in regulating Cd migration in acidic soil–plant systems. The study revealed that lime-based materials synergistically regulated Cd migration through two processes: chemical fixation and ionic competition. Results showed lime application reduced soil available Cd by 33.0%, decreased grain Cd by 44.8%, increased soil pH by 15.6%, and enhanced exchangeable Ca by 35.2%. Chemical fixation was evidenced by Cd transformation from labile to stable forms (residual Cd: +29.5%, acid-soluble Cd: −17.5%). Ionic competition was quantitatively confirmed through strong negative correlation between exchangeable Ca and grain Cd (R² = 0.704). Among the materials, Ca(OH)₂ exhibits the highest efficiency in rapid pedogenic passivation (58.7% reduction in available Cd), whereas CaCO₃ demonstrates superior long-term grain Cd attenuation (65.7% inhibition) via sustained Ca²⁺ release and rhizosphere-regulated dissolution. This study advances mechanistic understanding of Cd bioavailability control and establishes quantitative frameworks for predicting ecotoxicological outcomes, providing scientific basis for optimizing remediation strategies to minimize Cd transfer through agricultural food chains. Full article