Search Results (804)

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder marked by progressive kidney enlargement and cyst formation, often resulting in end-stage renal disease (ESRD). Oxidative stress (OxS) significantly contributes to renal damage in chronic kidney disease (CKD) and ADPKD. While the Mediterranean diet (Med-diet) is known for its antioxidative and anti-inflammatory effects, its impact on OxS in ADPKD remains unclear. This study aimed to assess the relationship between adherence to the Med-diet, OxS levels, and renal function in ADPKD patients. We enrolled 63 ADPKD patients aged 18–70 years with CKD stages G2–G4. Adherence to the Med-diet was evaluated using the PREDIMED questionnaire. OxS markers (NOX2-derived peptide [sNOX2-dp] and hydrogen peroxide [H₂O₂]) were measured via ELISA. Correlations between these markers, Med-diet adherence, serum creatinine, and estimated glomerular filtration rate (eGFR) were analyzed. Higher adherence to the Med-diet was associated with significantly lower OxS markers (sNOX2, p < 0.001; H₂O₂, p = 0.04). Reduced NOX2 and H₂O₂ levels correlated with lower creatinine and higher eGFR (NOX2, p < 0.001; H₂O₂, p < 0.001), suggesting an inverse relationship between OxS and renal function. In conclusion, adherence to the Mediterranean diet appears to be associated with lower levels of oxidative stress and may slow the progression of chronic kidney disease. These findings suggest that dietary interventions could mitigate disease progression by modulating OxS. Further studies are needed to confirm these results and explore the long-term effects of the Med-diet on disease progression. Full article

This study provides a comprehensive analysis of the impact of different marine fuels such as heavy fuel oil (HFO), methane, methanol, ammonia, or hydrogen, on energy efficiency and pollutant emissions in maritime transport, using a combined application of the Energy Efficiency Design Index (EEDI), Energy Efficiency Operational Indicator (EEOI), and Carbon Intensity Indicator (CII). The results show that methane offers the most balanced alternative, reducing CO₂ by more than 30% and improving energy efficiency, while methanol provides an intermediate performance, eliminating sulfur and partially reducing emissions. Ammonia and hydrogen eliminate CO₂ but generate NO_x (nitrogen oxides) emissions that require mitigation, demonstrating that their environmental impact is not negligible. Unlike previous studies that focus on a single fuel or only on CO₂, this work considers multiple pollutants, including SO_x (sulfur oxides), H₂O, and N₂, and evaluates the economic cost of emissions under the European Union Emissions Trading System (EU ETS). Using a representative model ship, the study highlights regulatory gaps and limitations within current standards, emphasizing the need for a global system for monitoring and enforcing emissions rules to ensure a truly sustainable and decarbonized maritime sector. This integrated approach, combining energy efficiency, emissions, and economic evaluation, provides novel insights for the scientific community, regulators, and maritime operators, distinguishing itself from previous multicriteria studies by simultaneously addressing operational performance, environmental impact, and regulatory gaps such as unaccounted NO_x emissions. Full article

CO₂ corrosion remains a critical challenge for the safe and reliable operation of Carbon Capture, Utilization, and Storage (CCUS) infrastructure. This review summarizes CO₂ corrosion implications from material selection, exposure time, CO₂ phase behavior, flow conditions, and impurities such as H₂O, O₂, SO_x, NO_x, and H₂S. CO₂ corrosion modeling has, since early works by de Waard in 1975, expanded to a wide range of models and software tools, many of which have already been reviewed and compared. This work provides a historical timeline and a comparative summary of models and software tools to assist in selecting models for CCUS applications. Modeling approaches are classified into empirical, semi-empirical, and mechanistic categories, with their assumptions, strengths, and limitations. CO₂ corrosion modeling has persistent challenges relating to data quality, data quantity, and parameter interactions, which reduce model accuracy, especially for machine learning approaches. The provided perspective emphasizes that machine learning and hybrid modeling approaches for CO₂ corrosion prediction are gaining popularity, and their effectiveness is currently limited by the quality and quantity of available corrosion data. The provided opportunities include recommendations for standardized experimental procedures and hybrid modeling strategies that combine physics-based insights from mechanistic modeling approaches with data-driven machine learning approaches. Full article

The behavior of the carbon cycle within the Land-Ocean Aquatic Continuum (LOAC) is shaped not only by aquatic processes but also by chemical interactions occurring at the atmosphere–water interface. In particular, the transport of acid rain precursors such as SO₂ and NO_x to surface waters via deposition can alter the water’s pH balance, thereby affecting Dissolved Inorganic Carbon (DIC) fractions and CO₂ emission potential. In this study, air quality measurements from three monitoring stations (Bosna, Karatay, and Meram) in Konya province of Türkiye, along with precipitation and temperature data from a representative meteorological station for the period 2021–2023, were analyzed using the Mann–Kendall Trend Test. Additionally, seasonal pH values of groundwater were examined, and their trends were compared with those of the other variables. The findings reveal striking differences on a station basis. At the Bosna station, while NO (Z = 10.80), NO₂ (Z = 9.47), and NO_x (Z = 10.04) showed strong increasing trends, O₃ decreased significantly (Z = −15.14). At the Karatay station, significant increasing trends were detected for CO (Z = 10.01), PM₁₀ (Z = 8.59), SO₂ (Z = 5.55), and NO_x (Z = 2.44), whereas O₃ exhibited a negative trend (Z = −6.54). At the Meram station, a significant decrease was observed in CO (Z = −11.63), while NO₂ showed an increasing trend (Z = 3.03). Analysis of meteorological series indicated no significant trend in precipitation (Z = −0.04), but a distinct increase in temperature (Z = 2.90, p < 0.01). These findings suggest that the increasing NO_x load in the Konya atmosphere accelerates O₃ consumption and, combined with rising temperatures, creates a potential for change in the carbon chemistry of aquatic systems. The results demonstrate that atmospheric pollutant trends constitute an indirect but significant pressure factor on the aquatic carbon cycle in semi-arid regions and highlight the necessity of integrating atmospheric processes into carbon budget analyses within the scope of LOAC. Full article

Nitrogen oxides (NO_x) emitted mainly from vehicle exhaust significantly contribute to urban air pollution, leading to photochemical smog and secondary particulate matter. Photocatalytic technology has emerged as a promising solution for continuous NO_x decomposition under ultraviolet (UV) irradiation. This study developed an eco-friendly permeable concrete incorporating activated loess and zeolite to improve roadside air quality. The high porosity and adsorption capability of the concrete provided a suitable substrate for a TiO₂-based photocatalytic coating. A single-component coating system was optimized by introducing colloidal silica to enhance TiO₂ particle dispersibility and adding a binder to secure durable adhesion on the concrete surface. The produced permeable concrete met sidewalk quality standards specified in SPS-F-KSPIC-001-2006. Photocatalytic NO_x removal performance evaluated by ISO 22197-1 showed a maximum removal efficiency of 77.5%. Even after 300 h of accelerated weathering, the activity loss remained within 13.8%, retaining approximately 80% of the initial performance. Additionally, outdoor mock-up testing under natural light confirmed NO_x concentration removal and formation of nitrate by-products, demonstrating practical applicability in real environments. Overall, the integration of permeable concrete and a durable, single-component TiO₂ photocatalytic coating provides a promising approach to simultaneously enhance pavement sustainability and reduce urban NO_x pollution. Full article

The continuous tightening of emission regulations and the escalating costs of palladium (Pd) and rhodium (Rh) have renewed interest in platinum (Pt)-based three-way catalysts (TWCs) as cost-effective alternatives for gasoline aftertreatment. However, despite extensive studies on Pt/CeO₂ and Pt/Ba-based formulations, the cooperative roles of Ba and Ce and, in particular, the fundamental influence of the Ba/Ce ratio on oxygen mobility, NO_x storage behavior, and Pt–support interactions remain poorly understood. In this work, we address this gap by systematically tuning the Ba/Ce molar ratio in a series of Pt–Ba–Ce/Al₂O₃ catalysts prepared from Ba(CH₃COO)₂ and CeO₂ precursors, and evaluating their structure–function relationships in both fresh and hydrothermally aged states. Through comprehensive characterization (N₂ physisorption, XRD, XPS, H₂-TPR, NO_x-TPD, SEM, CO pulse adsorption, and dynamic light-off testing), we establish previously unrecognized correlations between Ba/Ce ratio–dependent structural evolution and TWC performance. The results reveal that the Ba/Ce ratio exerts a decisive control over catalyst textural properties, Pt dispersion, and interfacial Pt–CeO₂ oxygen species. Low Ba/Ce ratios uniquely promote Pt–Ce interfacial oxygen and O₂ spillover—providing a new mechanistic basis for enhanced low-temperature oxidation and reduction reactions—while higher Ba loading selectively drives BaCO₃ formation and boosts NO_x storage capacity. A clear volcano-type dependence of NO_x storage on the Ba/Ce ratio is demonstrated for the first time. Hydrothermal aging at 850 °C induces PtO_x decomposition, BaCO₃–Al₂O₃ solid-state reactions forming inactive BaAl₂O₄, and Pt sintering, collectively suppressing Pt–Ce interactions and reducing TWC activity. Importantly, an optimized Ba/Ce ratio is shown to mitigate these degradation pathways, offering a new design principle for thermally durable Pt-based TWCs. Overall, this study provides new mechanistic insight into Ba–Ce cooperative effects, establishes the Ba/Ce ratio as a critical and previously overlooked parameter governing Pt–support interactions and NO_x storage, and presents a rational strategy for designing cost-effective, hydrothermally robust Pt-based alternatives to Pd/Rh commercial TWCs. Full article

The impact of the aviation sector on the Earth’s atmosphere and climate is not limited to the effects of CO₂ emissions generated by the combustion of hydrocarbon-based fuel in an aircraft engine. It is complemented by other combustion products and non-CO₂ emissions, such as CO, NO_x, unburnt hydrocarbons (UHCs), and soot, as well as the formation of condensation trails (contrails) as a result of emitted H₂O and condensation nuclei. To evaluate the overall atmospheric impact of an aircraft mission, it is necessary to model the aero engine and the combustion chamber in context with the atmospheric conditions over the course of the flight trajectory. Following that rationale, this paper presents the novel multidisciplinary ‘Modeling and System analysis of Aero Engines’ (MSAE) platform, aiming to evaluate the emission products over the flight trajectory with realistic atmospheric and operative boundary conditions. MSAE comprises an ambient condition model, an aircraft operating model, an aero engine performance model, and a combustion chamber model. The functionality of the individual models as well as their interconnections are demonstrated using the example of an Airbus A320 powered by an International Aero Engines V2500-A1 turbofan engine. Non-CO₂ emissions, including CO, NO_x, UHC, and soot emission indices, can be predicted at a selected operating point. Furthermore, an evaluation of contrail formation for both annually averaged and intraday ambient conditions is conducted, showing the benefit of considering ambient conditions in a finer temporal resolution. The results show the functionality of the presented MSAE platform and the necessity of performance and emission analysis under realistic conditions. Full article

In response to the challenges of deep peak shaving of coal-fired power plants and co-firing with combustible gases for achieving carbon neutrality and peaking emissions, this paper synthesizes combustion and ignition models for pulverized coal, with particular emphasis on volatilization analysis, gas-phase combustion, solid-phase combustion, and NOx formation mechanisms. It reviews studies on the combustion behaviors of pulverized coal when co-firing with gases such as CH₄, H₂, and NH₃, as well as the application of typical co-firing gases in pulverized coal furnaces. The ignition process hinges on whether the concentration of released combustible gases reaches the combustion range and ignition temperature, necessitating detailed volatilization analysis models and simplified gas-phase reaction models. Co-firing enhances combustion stability by facilitating gas ignition and sustained combustion, while pulverized coal achieves extended burning duration. Fuel-type NOx serves as a critical factor in ensuring the reliability of NOx numerical simulations and should be integrated with carbon combustion models. Full article

Hydrogen internal combustion engines are a promising propulsion technology due to their zero-carbon emission potential and high efficiency. However, achieving stable mixture formation during direct hydrogen injection remains a key challenge affecting ignition stability and NO_x emissions. Although numerous studies address the combustion characteristics of hydrogen, only a limited number have examined the transient behavior of hydrogen/air mixing during the intake stroke, particularly its interaction with in-cylinder flow structures prior to ignition. This lack of detailed insight into early mixture stratification and jet-driven turbulence represents a significant research gap that currently limits further optimization of DI-H₂ICE systems. This study therefore deals with the numerical analysis of the process of mixing hydrogen with air in the combustion chamber of a direct hydrogen injection engine (DI-H₂ICE). A 3D CFD model of a hydrogen direct-injection engine was used to evaluate in-cylinder mixing during the intake and early compression strokes. Unlike most existing publications that focus primarily on combustion or emission formation, this work examines the mixing process from the beginning of the intake stroke and provides a new evaluation of the evolution of the hydrogen jet and its interaction with the piston-induced swirl as the crankshaft angle changes. The simulation covers the section from the exhaust top dead center (TDC) to the early compression phase, during which hydrogen is injected at a high pressure. The results show that the shape of the combustion chamber and the interaction of the hydrogen jet with the piston significantly affect the distribution of the equivalent ratio and the intensity of the swirl. Quantitative evaluation showed that the mixture remained lean overall throughout the cycle: typical hydrogen mass fractions in the cylinder ranged from 0.01 to 0.05, corresponding to equivalence ratios of φ = 0.35–1.81 (λ = 2.85–0.55). Only the core of the jet reached an instantaneous local mass fraction of 0.96, representing undiluted hydrogen and not a combustible mixture. No persistent zones with φ > 1 were detected, confirming that the chosen injection strategy prevents the formation of locally rich pockets. This study confirmed that a suitably selected injection configuration and combustion chamber geometry can significantly contribute to a uniform mixture distribution, a more stable combustion process, and lower NO_x production. The presented findings provide a methodological basis for improving mixture formation strategies in hydrogen engines and may support the development of efficient, zero-carbon powertrains in future mobility systems. Full article

The selective catalytic reduction (SCR) system is a key component for addressing NOx emissions from internal combustion engines. To resolve the issues of modeling distortion in SCR systems and the difficulty in characterizing the local reaction mechanism, a multi-dimensional SCR reaction model based on the coupling of Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) dual mechanisms was established and conducted by experiment. The SCR catalytic characteristics and the dual-mechanism reaction process were systematically investigated. Additionally, based on the combined analysis of species concentration distribution coupled with temperature characteristics, a calculation method for the synergy of concentration-temperature fields was developed, and the synergistic characteristics of the concentration-temperature fields were explored. The results showed that high load accelerated the light-off speed, but this effect was counteracted by the negative impact of high flow rate. A strong negative correlation was maintained between temperature and NOx concentration across the full load range, and the axial consistency increased with load increasing. The results provide important theoretical support for the mechanism analysis of diesel engine SCR reactions and the optimization of thermal management. Full article

Isoprene (C₅H₈), the most abundant biogenic volatile organic compound (400–600 Tg C yr⁻¹), exerts complex NO_x-dependent influence on tropospheric ozone, yet its representation remains absent in many climate models. This study aims to quantify isoprene’s impact on tropospheric chemical composition using the Russian Earth system model INM-CM6.0 with newly implemented isoprene oxidation chemistry. Two 12-year experiments (2008–2019) were conducted: a control run without isoprene and an experiment with the Mainz Isoprene Mechanism (MIM1: 44 reactions, 16 species). Results reveal a NO_x-dependent two-layer vertical structure. In the tropical surface layer (0–5 km, 20° S–20° N), ozone decreases by 10–15 ppb through radical termination under low-NO_x (<100 ppt), with 15–30% OH reduction and 30–60% CO increase. In the middle troposphere (8–12 km), ozone increases by 10–15 ppb through thermal decomposition of vertically transported PAN and MPAN. In subtropics (20–35°) with elevated NO_x (>500 ppt), isoprene stimulates ozone formation at all altitudes (+3–12 ppb). Oxidation product distributions establish a spatial hierarchy: local (ISON, NALD: 0–5 km), regional (MPAN: to 8 km), and global (PAN: reaching high latitudes at 8–12 km). Comparison with CAMS, MERRA-2, and ERA5 reanalyses shows substantial improvement: tropical CO discrepancies decrease from 20–30% to 10–15%, OH by factors of 2–3, and ozone overestimation from 30–40% to 10–15%. These findings demonstrate that explicit isoprene chemistry is essential for accurate tropospheric composition simulation, particularly given the projected 21–57% emission increases by 2100 under climate warming. Full article

This study explores the effects of exogenous SELENOV on cellular migration, viability, mitochondrial function, ROS production, and Ca²⁺ signaling in mouse fibroblast L-929 and testicular teratoma F-9 cells. In scratch assays, 50–100 µg/mL SELENOV significantly inhibited F-9 cell migration after 48 h, while in L-929 fibroblasts, only 100 µg/mL had a suppressive effect. Viability assays revealed strong cytotoxicity in F-9 cells. Critically, at a dose of 50 µg/mL (where the corresponding volume of solvent buffer alone was non-toxic), SELENOV reduced survival to 19%, triggering late apoptosis in 76% of cells, whereas in L-929 cells, comparable effects required 100 µg/mL. Mitochondrial depolarization (JC-1/Rhodamine-123 assays) was pronounced in F-9 cells even at 50 µg/mL, while L-929 cells responded only to 100 µg/mL. Similarly, 50 µg/mL SELENOV induced significant ROS overproduction in F-9 but not in L-929 cells, correlating with upregulated NOX1, NOX4, GPX3, and GPX4 expression. Ca²⁺ imaging showed dose-dependent [Ca²⁺]ᵢ elevation, with 50 µg/mL SELENOV inducing a sustained rise in F-9 cells, whereas L-929 cells required higher doses. Strikingly, 50 µg/mL SELENOV in F-9 cells downregulated BCL-2 and BCL-xL while upregulating pro-apoptotic BAX and PUMA, suggesting selective activation of intrinsic apoptosis. These results demonstrate that F-9 cancer cells are significantly more sensitive to SELENOV than normal fibroblasts, with 50 µg/mL sufficient to trigger mitochondrial dysfunction, oxidative stress, and apoptosis. The findings highlight SELENOV’s potential as a targeted anticancer agent, particularly for germ cell tumors. Full article

Green coconut husk is an abundant and underutilized agro-industrial residue in Brazil, contributing significantly to landfill overload. This study investigates the pyrolysis of pellets derived from this biomass as a technological alternative for its valorization, focusing on the integrated characterization of the three resulting products. Pellets were subjected to pyrolysis in a fixed-bed reactor under two distinct conditions: at 400 °C to maximize biochar production, and at 600 °C to enhance gas generation. The raw material and resulting solid, liquid, and gaseous fractions were characterized using physicochemical, thermal, morphological, and chromatographic analyses. Pyrolysis at 400 °C yielded biochar with high fixed carbon content (67.03%) and elevated heating value (27.80 MJ/kg), suitable for soil amendment and carbon sequestration. At 600 °C, the non-condensable gas exhibited a higher hydrogen concentration (35.84%) and an H₂/CO ratio of 1.84, favorable for chemical synthesis applications. Notably, palletization resulted in a significant bio-oil and gas yield even under 400 °C. The bio-oil underwent chemical upgrading, which significantly increased the phenolic content and raised its heating value to 20.40 MJ/kg. Additionally, combustion tests revealed that the gas produced emitted lower levels of NOx compared to natural gas. Full article

Nitric acid (HNO₃) is predominantly produced in large production plants using the Ostwald process. In view of its widespread application as synthetic fertilizer, small- scale and local production has become of interest. The chemical precursor of nitric acid is NO_x gas, which can be produced from air at percentage-level concentrations using small-scale, electrically powered warm plasma reactors. Using gas-phase plasma, the downstream conversion of NO_x into fertilizer is a crucial, but as yet understudied step. This work aims to help close this gap and support the further development of plasma-driven nitrogen fixation and subsequent NO_x scrubbing. The chemistry of NO_x absorption through gas scrubbing is investigated at a 1% NO_x concentration using a synthetic mimic of a plasma-produced NO_x stream in order to maintain maximal controllability. pH values of the scrubber solution were kept in the range of 1 to 5 and it was recirculated for up to 30 h. The kinetics of NO_x absorption were found to be strongly pH-dependent, requiring several hours of recirculation to reach steady state conditions. Once at steady state, the NO_x removal efficiency turned out to be rather pH independent and reached around 84% for experiments at pH 1–4. The formation of nitrous acid (HNO₂) byproduct reached a constant value of around 3.43 mM based on a dynamic equilibrium of its formation and decomposition. Approaches to minimize undesired nitrite and nitrous acid byproduct formation are discussed. Full article

Simultaneous catalytic elimination of nitrogen oxides (NO_x) and volatile organic compounds (VOCs) represents a promising technology for addressing the synergistic pollution of fine particulate matters of <2.5 μm diameter (PM_2.5) and O₃. Nevertheless, it has been maintaining significant challenges in practical implementation, particularly the inherent mismatch in temperature windows between NO_x reduction and VOCs oxidation pathways, coupled with catalyst poisoning and deactivation phenomena. These limitations have hindered the industrial application of bifunctional catalysts for the removal of concurrent pollutant. This review systematically explored the fundamental mechanisms and functional roles of active sites in controlling synchronous catalytic processes. The mechanism of catalyst deactivation caused by multiple toxic substances has been comprehensively analyzed, including sulfur dioxide (SO₂), water vapor (H₂O), chlorine-containing species (Cl*), reaction by-products, and heavy metal contaminants. Furthermore, we critically evaluated the strategies of doping regulation, nanostructure engineering and morphology optimization to enhance the performance and toxicity resistance of catalysts. Meanwhile, emerging regeneration techniques and reactor design optimizations are discussed as potential solutions to improve the durability of catalysts. Based on the above critical aspects, this review aims to provide insights and guidelines for developing robust catalytic systems capable of controlling multi-pollutants in practical applications, and to offer theoretical guidance and technical solutions to bridge the gap between laboratory research and industrial environmental governance applications. Full article