Search Results (4,196)

Background: Submarines represent extremely confined environments where breathing air is continuously recirculated for extended periods with minimal renewal, generating complex multipollutant atmospheres. Objectives: This critical narrative review aims to (i) summarize sources and composition of submarine indoor air, (ii) evaluate respiratory and cardiovascular risks for crews, and (iii) assess current purification technologies. Methods: A narrative review was conducted following PRISMA recommendations applicable to non-systematic reviews. The PubMed search covered all years from inception to September 2025, complemented by backward citation tracking and technical reports. Results: Eligible studies consistently report elevated levels of CO₂, VOCs, NO_X, CO, PM_2.5, and bioaerosols aboard submarines. Evidence from submariner cohorts and toxicological studies indicates risks of airway irritation, impaired mucociliary defenses, endothelial dysfunction, cardiovascular stress, and neurobehavioral alterations. Conclusions: Submarine indoor air quality is a credible determinant of crew health. Existing filtration systems mitigate some risks but do not address multipollutant mixtures adequately. Improved real-time monitoring, advanced filtration, CFD-guided airflow optimization, and longitudinal medical surveillance are necessary. 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

Achieving efficient and clean use of low-volatile coal is of vital importance to China’s energy system. This study aims to elucidate how the high-concentration-CO₂ atmosphere influences the migration pathways of fuel-bound nitrogen during the pyrolysis of low-volatile coal, thereby providing critical insights for the prediction and control of NO_x emissions under oxy-fuel conditions. A high-temperature drop-tube furnace system capable of high heating rates (up to 10⁴–10⁵ °C/s) was employed to comparatively investigate the pyrolysis behavior of a typical low-volatile coal (volatile matter content of 7.44%) under Ar and pure CO₂ atmospheres at 1000–1400 °C. The outcomes show that the CO₂ atmosphere significantly promoted the release of volatiles, with the volatile release rate at 1400 °C reaching 2.1 times that under the Ar atmosphere. While volatile nitrogen primarily consists of HCN and NH₃ with HCN dominance at lower temperatures, NH₃ release exceeds HCN by more than tenfold at 1400 °C. CO₂ promotes nitrogen release through enhanced gasification reactions, reducing char nitrogen proportion while increasing volatile nitrogen yield approximately fourfold at elevated temperatures. The X-ray photoelectron spectroscopy analysis reveals the transformation pathway of nitrogen functionalities from quaternary nitrogen to pyridine nitrogen and subsequently to pyridine under oxy-fuel conditions. These findings provide fundamental insights into fuel nitrogen evolution mechanisms and offer theoretical support for optimizing oxy-fuel combustion processes toward efficient NO_x control. Full article

Skeletal muscle atrophy underlies sarcopenia, frailty, and muscular dystrophies, but the molecular mechanisms linking oxidative stress to muscle degeneration remain incompletely understood. We previously identified protein complex formation between transient receptor potential canonical 3 (TRPC3) and NADPH oxidase 2 (Nox2) as a key driver of anthracycline-induced myocardial atrophy. Here, we investigated whether this complex also contributes to skeletal muscle wasting. In skeletal muscle from sciatic nerve transection model mice and Duchenne muscular dystrophy (mdx) mice, TRPC3-Nox2 complex formation was enhanced. TRPC3 deletion significantly attenuated denervation-induced soleus atrophy and reduced reactive oxygen species (ROS) production. TRPC3-Nox2 complex formation was upregulated in the soleus muscle (SM) of mdx mice. Pharmacological disruption of the TRPC3-Nox2 interaction improved muscle size and strength and reduced plasma creatine kinase in mdx mice. A recombinant adeno-associated virus (AAV) encoding a TRPC3 C-terminal peptide was used to suppress TRPC3-Nox2 complex formation in vivo. AAV-mediated expression of TRPC3 C-terminal peptide mitigated muscle wasting (CSA) in mdx mice, while muscle strength and plasma CK were not significantly improved. Thus, TRPC3-Nox2 complex formation may be a pivotal driver of oxidative stress-mediated skeletal muscle atrophy. Targeting this protein–protein interaction represents a promising therapeutic strategy for Duchenne muscular dystrophy (DMD) and other intractable muscle-wasting disorders. Full article

We aimed to investigate the association between oxidative stress (OS), inflammation, and kidney function and the predictive ability of OS for mortality and cardiovascular disease in 143 patients with type 2 diabetes (T2DM) and various degrees of kidney function. At baseline, we assessed catalase, nitrogen oxides (NOx), malondialdehyde (MDA), advanced oxidation products (AOPPs), myeloperoxidase (MPO)], kidney function, and C-reactive protein (CRP). All patients were followed for 57 months, with the combined primary outcome of death/cardiovascular (CV) event, whichever occurred first. NOx was an independent predictor of estimated glomerular filtration rate (B = −0.097, p = 0.006), and MPO was correlated with glycated hemoglobin (r = 0.17, p = 0.046), CRP (r = −0.18, p = 0.032), and serum albumin (r = 0.2, p = 0.011, Spearman’s rho). During the follow-up, 24 composite events were documented. Kaplan–Meier curves showed that smoking (p = 0.029), serum albumin (p = 0.014), and MPO (p = 0.024, log-rank test) were associated with the outcome. In multivariate Cox regression models, smoking and MPO were independent predictors of the composite outcome (hazard ratio—HR = 2.8, p = 0.004, 955 confidence interval—CI 1.05–7.5 and HR = 0.99, p = 0.015, 95% CI: 0.98–1.00, respectively), after adjustment for several cofactors. OS might be associated with CV disease in T2DM. Full article

Industrial air emissions are major contributors to human exposure to toxic pollutants, posing significant health risks. Life cycle assessment (LCA) is increasingly used to quantify human toxicity impacts from industrial processes. Conventional LCA often overlooks spatial and temporal variability, limiting its ability to capture actual inhaled doses and exposure-driven impacts. To address this, we developed a site-dependent dynamic LCA (SdDLCA) framework that integrates conventional LCA with Enhanced Structural Path Analysis (ESPA) and atmospheric dispersion modeling. Applied to the production of double-glazed PVC windows for a residential project, the framework generates high-resolution, site-specific emission inventories for three key pollutants: nitrogen oxides (NO_x), sulfur dioxide (SO₂), and fine particulate matter (PM_2.5). Local concentration fields are compared with World Health Organization (WHO) air quality thresholds to identify hotspots and periods of elevated exposure. By coupling these fields with the ReCiPe 2016 endpoint methodology and localized demographic and meteorological data, SdDLCA quantifies human health impacts in Disability-Adjusted Life Years (DALYs), providing a direct measure of inhalation toxicity. This approach enhances LCA’s ability to capture exposure-driven effects, identifies populations at greatest risk, and offers a robust, evidence-based tool to guide industrial planning and operations that minimize health hazards from air emissions. Full article

The present work adopts a cooled cooling air (CCA) technology based on the integrated aircraft/engine thermal management concept, by coupling an air-kerosene heat exchanger with a high-temperature combustor. Using the heat exchanger, kerosene is preheated to near-critical and supercritical conditions, and the combustion characteristics of kerosene at ambient, near-critical, and supercritical states were investigated. The combustion performance tests were carried out in a model combustor under varying fuel-to-air ratios (FARs) and different kerosene injection conditions. The experimental results show that when the combustor’s FAR is increased to 0.055, the supercritical kerosene exhibits significant advantages over kerosene of the ambient state. The comparison of the combustion performance parameters shows that the combustor outlet temperature distribution factor (OTDF) and radial temperature distribution factor (RTDF) decrease by 52.26% and 51.07%, respectively; in terms of the pollutant emissions, the CO emission index (EI_CO) and unburned hydrocarbon emission index (EI_UHC) are reduced by 66.63% and 68.33%, respectively, while the NOx emission index (EI_NOx) increases by 76.26%, and the combustion efficiency improves by 2.0%. It is noteworthy that once the kerosene reaches the supercritical state, the threshold for the optimal FAR in the combustor rises to 0.055, which carries the significant engineering value for enhancing an aero-engine combustor’s operability across variable conditions and its low-emission combustion performance. Full article

Background/Objectives: Astrocytic redox-inflammatory signaling has been implicated in Parkinson’s disease (PD) pathology and may constrain hippocampal neurogenesis. We previously identified an astrocytic NOX4–MPO–OPN axis associated with impaired neurogenic capacity. Here, we tested whether a saffron-derived antioxidant (SDA; Crocus sativus extract) and Passiflora incarnata L. extract (PI) modulate this pathway in an MPTP-induced PD mouse model. Methods: Male C57BL/6J mice were randomized to Sham, MPTP, and treatment groups (n = 9/group for behavior; n = 4–5/group for histology/immunoblotting). SDA or PI (50 mg/kg/day, oral, 5 weeks) was administered, with resveratrol as a positive control. Behavioral, histological, and molecular analyses were performed by investigators blinded to group allocation where feasible. Results: SDA and PI were associated with reduced NOX4/MPO/OPN signals, mainly in GFAP-positive astrocytes, along with recovery of neurogenesis markers (Ki67, DCX, BrdU/NeuN) and synaptic markers (PSD95, synaptophysin), and improved motor performance. Mitochondrial and oxidative injury markers (TIM23, TOM20, OXPHOS subunits; 4-HNE) and apoptotic markers (Bax, cleaved caspase-3, Bcl-2) also shifted toward Sham levels. Given previous reports of Passiflora extracts’ sedative effects, we note that metabolic measures (body weight, food intake, and water intake) were similar across groups; however, specific tests for sedation or arousal were not conducted. Conclusions: These findings offer preclinical evidence that SDA and PI modulate redox-inflammatory and mitochondrial stress signatures and are associated with neurogenic, synaptic, and behavioral improvements in an acute MPTP model. Further validation in chronic/genetic PD models and pharmacokinetic/brain exposure studies will be necessary to confirm their translational potential. Full article

Chronic liver disease (CLD) encompasses a spectrum of progressive disorders, including metabolic dysfunction steatotic-associated liver disease (MASLD) and primary biliary cholangitis (PBC), which together represent a significant global health burden with few effective therapeutic options. The fibrogenic process, common to most forms of CLD, is driven by a complex interplay of cellular stress, inflammation, and wound-healing responses. Nicotinamide adenine dinucleotide phosphate oxidase isoforms 1 and 4 (NOX1 and NOX4) have emerged as key enzymatic sources of reactive oxygen species (ROS), serving as central mediators of hepatic oxidative stress, fibrogenesis, and inflammation. Setanaxib is a first-in-class, orally bioavailable, selective dual inhibitor of NOX1 and NOX4 that has progressed to clinical evaluation. This review synthesizes current knowledge on the molecular pharmacology of the NOX1/4 axis, preclinical evidence from translational models, and clinical trial outcomes to critically assess the therapeutic potential of targeted NOX inhibition in hepatic fibrosis. By attenuating hepatic stellate cell activation, modulating TGF-β signaling, reducing extracellular matrix (ECM) deposition, and regulating hepatic macrophage polarization, setanaxib exhibits pleiotropic antifibrotic effects. The compound also demonstrates favorable pharmacokinetic properties and a good safety profile in patients with PBC, with emerging evidence suggesting meaningful improvements in fatigue and quality of life. Finally, we examine the complex, and sometimes paradoxical, roles of NOX4 in liver pathophysiology, compare the evolving therapeutic landscape with other approaches such as farnesoid X receptor (FXR) agonists, and propose future paradigms integrating artificial intelligence–driven predictive modeling to optimize patient stratification and therapeutic response in this new era of redox-targeted hepatoprotective therapy. Full article

Over the past decade, oxidative stress and neuroinflammation have been increasingly recognized as part of the pathology of Alzheimer’s disease (AD). This observation has led to extensive efforts and attempts to apply antioxidant compounds as therapeutic agents for AD and other pathologies. However, most, if not all, of these attempts have failed in preclinical or clinical trials. A tentative explanation for this failure is radical scavengers’ intrinsic lack of specificity in either their mode or district of action. The lack of specificity has been thought by some to be a source of so-called “reductive stress”, another form of redox imbalance that might be just as toxic as oxidative stress. Thus, research interest is shifting from developing simple radical scavengers to designing and refining compounds targeting the overproduction of Reactive Oxygen Species (ROS) in specific pathological conditions. This can be achieved, for instance, by targeting the enzymes that are mainly responsible for their production, namely NADPH oxidases (NOX). In this review, we will discuss, from the point of view of medicinal chemistry, the main innovations in the development of NOX inhibitors and their potential employment for AD therapy. We will also discuss the experimental hurdles that slow down research in this field and possible solutions. Full article

NO, NO₂, and O₃ were measured for 1 year at a suburban site in the southeast Mediterranean. NO preserved no seasonality, but significant seasonal variations were obtained for NO₂ and O₃. These pollutants exhibited inverse trends with higher NO₂ levels measured during wintertime, whilst higher O₃ levels were measured during summertime. Photochemistry was the primary reason for the opposing variations in both pollutants, although O₃ levels were frequently increased due to O₃-rich plumes travelling from northeast Europe, highlighting the impact of regional contributions in the measured concentrations. Nevertheless, anthropogenic sources were identified and contributed to both NO and NO₂. Diurnal variations analysis showed that NO increased usually in the early morning and was linked with primary emissions from traffic. NO₂ increased simultaneously with NO in the early morning, and besides primary vehicle emissions, it was associated with secondary formation from the emitted NO. Moreover, a significant contribution from domestic heating emissions on NO₂ was identified in the late evening during wintertime. Overall, a relative burden of weekdays was associated with NO (morning rush hours) and NO₂ (morning rush hours, evening), whereas weekends were burdened by O₃ due to the weekend effect. Comparison with European Union air quality standards showed that NO₂ was considerably lower than the limit values, but a significant number of exceedances were identified for O₃, especially during the warmer months. This finding suggested the relative burden of the study site from O₃. In conclusion, NO at the study site was influenced by primary traffic emissions, whereas NO₂ had both primary and secondary contributions, and together with photochemistry, both pollutants governed O₃ diurnal and seasonal cycles. Full article

To enhance the purification of exhaust gas, a g-C₃N₄/CeO₂/Bi₂O₃ dual type-II heterojunction photocatalysis was designed and prepared to suppress the recombination of electron–hole pairs and improve light energy utilization. The dual type-II heterojunction structure effectively reduced the bandgap (Eg) from 2.5 eV to 2.04 eV, thereby extending the light absorption of photocatalysis into the visible region. Following the design of the heterojunction, a self-cleaning process was developed and applied to asphalt pavement rut plates to evaluate its efficiency in degrading vehicle exhaust under real-road conditions. The coating was systematically characterized in terms of exhaust degradation efficiency, hardness, adhesion, water resistance, freeze–thaw durability, and skid resistance. Under 60 min of natural light irradiation, the purification efficiencies for HC, CO, CO₂, and NO_x reached 22.60%, 19.27%, 14.83%, and 50.01%, respectively. After three-repetition tests, the efficiencies remained high at 21.75%, 19.04%, 14.66%, and 49.83%, demonstrating excellent photocatalytic stability. All other road-performance indicators met the relevant China national standards. The application of this self-cleaning coating in road infrastructure presents a viable strategy for environmental remediation in transportation systems. 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

Neuropsychiatric disorders constitute an escalating public health challenge worldwide, with growing evidence suggesting that environmental factors like air pollution may contribute substantially. This prospective cohort study investigated the associations between long-term exposure to fine particulate matter (PM_2.5) and nitrogen oxides (NO_x) and the progression of eight neuropsychiatric disorders among 502,356 UK Biobank participants. Using multi-state models, we analyzed three distinct trajectory stages: stage 1 (transition from baseline healthy status to PHQ-4-positive mood disorders), stage 2 (transition from baseline to ICD-10-diagnosed disorders), and stage 3 (progression from PHQ-4-positive status to clinical diagnosis). Nonlinear exposure–response relationships were subsequently characterized using restricted cubic spline (RCS) regression models. The findings indicated that exposure to both PM_2.5 and NO_x per IQR increase was strongly associated with stage 1, with a corresponding hazard ratio of 1.28 (95% CI: 1.27–1.30) and 1.10 (95% CI: 1.09–1.11). Across the three stages, the risk pattern evolved from being broadly significant to one characterized by disease-specific significance. Alzheimer’s disease was consistently identified as the condition with the strongest association and highest risk linked to air pollution. Specifically, hazard ratios across stages were as follows: 1.08–1.13 in stage 2 and 1.14–1.20 in stage 3 for PM_2.5; and 1.04–1.05 in stage 2 and 1.05–1.10 in stage 3 for NO_x. Subgroup analyses identified heightened vulnerability in females (particularly subjects with depression, Parkinson’s disease, and sleep disorders), younger individuals, and socioeconomically deprived populations. These findings underscore the importance of considering air pollution as a modifiable risk factor in the prevention of neuropsychiatric disorders. Full article

As sustainable green fuels for heavy-duty engines, using hydrogen doping with ammonia helps to mitigate greenhouse gas emissions. Based on the background of hydrogen production from ammonia reforming, the combustion and emission characteristics of hydrogen-doped ammonia engines are studied. By employing 3D-CFD numerical simulation, this study systematically explores the combined effects of the ignition timing, hydrogen energy ratio (HER), and equivalence ratio (Φ) on the premixed combustion and emission performances of ammonia–hydrogen blends. The findings indicate that at the operating conditions of HER = 4% and Φ = 1.0, the indicated mean effective pressure (IMEP) reaches its maximum at −40 °CA aTDC, with the indicated thermal efficiency (ITE) reaching 48.2%. However, to mitigate knock hazards, the ignition timing should be adjusted to −37.5 °CA aTDC. With HER increasing from 4% to 25%, the flame propagation velocity is markedly improved, and the combustion duration is notably reduced. As the equivalence ratio rises from 0.8 to 1.0, the combustion intensity is strengthened while the proportion of indicated work declines. Notably, the lean burn condition (Φ = 0.8) exhibits no knock risk and achieves the highest ITE (49.2%). In terms of emission characteristics, advanced ignition timing, higher HER, and lower equivalence ratio all promote NO_X formation. In contrast, N₂O emissions decrease as the combustion temperature rises and the combustion duration shortens. Unburned NH₃ is mainly distributed in the low-temperature areas inside the cylinder, and its emission amount decreases with the improvement of combustion completeness. Full article