Search Results (9,215)

Environmental exposure to persistent and non-persistent endocrine-disrupting chemicals (EDCs), including per- and polyfluoroalkyl substances (PFAS), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), dioxins, phthalates, and bisphenols, has been increasingly associated with elevated cardiovascular disease (CVD) risk. Emerging evidence suggests the importance of gene–environment interactions in modulating individual susceptibility to EDC-related cardiovascular effects. This review summarizes current knowledge by synthesizing the main classes of EDCs, evaluating the evidence linking them to cardiovascular outcomes, and highlighting how genetic variability may modulate EDC-induced cardiovascular risk. Across the studies analyzed, the most extensively investigated genetic polymorphisms involve pathways related to oxidative stress regulation, xenobiotic metabolism and detoxification, hormone signaling, and lipid homeostasis. Variants in antioxidant defense genes, such as CAT, eNOS, and PON1, have been associated with increased hypertension risk and vascular dysfunction following exposure to bisphenols and PAHs. Polymorphisms in GSTP1, CYP2C19, CYP1A2, CYP2E1, ABCB1, and MTHFR may influence susceptibility to cardiometabolic alterations and congenital heart defects, whereas variants in ESR2, FTO, LEPR, and INSIG2 have been linked to obesity, dyslipidemia, and hypertension associated with PFAS, PBDEs, and bisphenols. A deeper understanding of gene–environment interactions is essential to advance preventive cardiology and mitigate the cardiovascular impact of environmental pollutants. Full article

Electrospun sulfonated polyketone (PK) nanofiber membranes were prepared to investigate the sulfonation-time-dependent structure–property relationships of hydrocarbon-based polymer electrolyte membranes for PEMFC (Polymer Electrolyte Membrane Fuel Cell) applications. NaCl addition to the electrospinning solution increased solution conductivity and enabled the formation of uniform PK nanofibers with an average diameter of approximately 270 nm. Subsequent sulfonation introduced sulfonic-acid-related groups into the PK nanofiber framework, and the resulting membrane properties were strongly governed by sulfonation time. Among the tested membranes, PK-NC16 exhibited the highest proton conductivity of 0.107 ± 0.031 S cm⁻¹ and an ion exchange capacity of 2.82 m_eq g⁻¹, exceeding or comparable to those of Nafion 115 under the tested conditions. FTIR-based analysis indicated that the relative sulfonation index increased up to 16 h, whereas extended sulfonation for 24 h generated additional sulfone/sulfonate-related bands, suggesting possible side reactions or structural changes under prolonged acid treatment. The high water uptake of PK-NC16 enhanced proton transport but also revealed a hydration-sensitive polymer network, as reflected by a voltage degradation rate of approximately −590 μV h⁻¹ during a 100 h short-term stability constant-current test. These results demonstrate that sulfonation time is a key parameter controlling the balance among ionic functionality, hydration, mechanical response, proton conductivity, and PEMFC-relevant single-cell performance in electrospun PK nanofiber membranes. Full article

Polycyclic aromatic hydrocarbons (PAHs) are widespread, persistent pollutants that can be sequestered within human adipose tissue due to their lipophilic nature. While this accumulation poses toxicological risks depending on dose and individual susceptibility, the specific morphological impact of chronic PAH storage on tissue architecture remains poorly defined. Here, we performed a histopathological and morphometric analysis on human subcutaneous adipose tissue samples characterized by high pyrene levels. We evaluated tissue organization, collagen distribution, the presence of inflammatory, neural, and vascular alterations and adipocyte morphometry to assess the structural response to PAH sequestration. Despite high pyrene concentrations, PAH-positive tissues maintained preserved overall architecture with normal collagen distribution, absence of lymphocytic infiltration, low macrophages, unaltered nerve fiber patterns, without evidence of vascular remodeling. Morphometry revealed smaller adipocyte area in PAH-positive samples, although not statistically significant. Our experimental data indicate that high PAH accumulation does not necessarily induce subcutaneous adipose tissue remodeling, suggesting that biochemical or metabolic alterations might occur even in the absence of evident histological changes. Further studies, with a broadened cohort, are needed to define the threshold at which PAHs’ presence translates into permanent tissue damage. Full article

Atmospheric wet deposition represents a major pathway for the transfer of organic micropollutants into terrestrial and aquatic ecosystems. This study investigates the occurrence and spatial distribution of polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs), and BTEX compounds in rainwater across Northern Serbia (Vojvodina region). Rainwater samples were collected during the 2025–2026 heating season at three locations: a petrochemical site in Kikinda, a traffic- and residentially influenced site in Sremska Mitrovica, and an urban background site in Sombor. Total concentrations showed pronounced spatial variability, with the highest ΣBTEX and ΣPAE levels recorded in Kikinda (∑BTEX = 2.818 μg L^∑1; ∑PAE = 0.930 μg L^∑1). Diagnostic ratios identified a dominant petrogenic signature in Kikinda (LMW/HMW > 1), while pyrogenic sources prevailed in Sremska Mitrovica and Sombor ((Fla/Fla + Pyr) > 0.5). BTEX profiles across all sites were characterised by the absence of benzene and elevated toluene and xylene levels (B/T ≈ 0; T/X > 1). Health risk assessment indicated an acceptable but non-negligible carcinogenic risk from PAHs, particularly for children in industrial areas. These findings highlight the role of precipitation as an efficient scavenger of organic pollutants and emphasise the need for integrated atmospheric–hydrological monitoring frameworks in industrialised regions. Full article

Dryland soils of the Caspian region of western Kazakhstan are exposed to environmental stress, including drought, alkalinity, low soil organic matter content, and anthropogenic pressure. In this preliminary study, bacterial communities were investigated in 18 soil samples collected from six sampling groups across Makat (M1, M2), Isatay (I1, I2), and Beyneu (B1, B2) districts. Soil physicochemical properties were measured, and bacterial diversity was analyzed using 16S rRNA gene sequencing of the V3–V4 region. Community composition analysis indicated spatial heterogeneity among the sampled groups. M1 and I1 showed the highest taxon richness, whereas B2 contained the highest number of unique taxa. Genus-level profiles showed that B1 and M2 were mainly associated with Rubrobacter and related actinobacterial taxa; B2 contained higher proportions of Marinobacter, Tychonema, Qipengyuania, and Halomonas; and I2 was enriched with Antarcticibacterium, Salinimicrobium, Rhodococcus, Gillisia, Marinobacter, Dietzia, and Pontibacter. Correlation analysis showed that several bacterial taxa were associated with soil organic matter content, total nitrogen, total phosphorus, exchangeable cations, and pH, although the overall Mantel relationship between soil properties and community structure was not significant. FAPROTAX-based prediction indicated differences in putative heterotrophic, nitrogen-related, sulfur-related, and hydrocarbon-associated functional categories among sites. Because FAPROTAX predictions are based on taxonomic composition, these results should be interpreted only as putative functional potential and not as evidence of actual microbial metabolic activity. These findings suggest that the sampled Caspian dryland soils contain distinct bacterial assemblages and taxa with potential ecological relevance; however, their role in dryland soil resilience or bioremediation should be verified through future culture-based, metagenomic, and functional validation studies. Full article

Environmental pollution by polycyclic aromatic hydrocarbons (PAHs) is a serious environmental problem. One of the effective methods of cleaning the environment from these toxicants is the use of sorbents based on clay minerals. Special organo-mineral, bio-mineral and bio-organo-mineral complexes were obtained. Organo-mineral complexes (organoclays) were synthesized on the basis of Na-bentonite and anionic, amphoteric and nonionic surfactants. Bio-mineral and bio-organo-mineral complexes were produced by inoculating bentonite and organoclays with a consortium of bacteria. The adsorption characteristics of the complexes to benzopyrene and naphthalene were studied. Modification of bentonite with various types of surfactants leads to a significant increase in the percentage adsorption of both benzopyrene and naphthalene, with benzopyrene being more so. All bio-organo-mineral complexes adsorb more benzopyrene than pure bentonite and the bentonite + bacteria complex. In most cases, this pattern is also characteristic of naphthalene adsorption. Organoclay complexes with bacteria adsorb PAHs in greater quantities than organoclays, typically at the average concentrations of benzopyrene and naphthalene used (30–60 μg mL⁻¹) and when modified with individual surfactants. Based on the determination coefficients, the adsorption of benzopyrene and naphthalene by all studied sorbents is best described by the Langmuir equation. The maximum (limiting) adsorption of benzopyrene by all organo-mineral complexes (organoclays) exceeds the maximum adsorption of benzopyrene by bentonite. Modification of bentonite with surfactants may not change, decrease, or increase the maximum adsorption of naphthalene compared to the original bentonite, depending on the surfactant used. Colonization of the organoclay surface by bacteria, with rare exceptions, results in a decrease in the maximum adsorption values of benzopyrene and naphthalene compared to organoclay, or has no effect at all. Full article

Tight oil and gas reservoirs have become an important alternative to conventional hydrocarbon resources worldwide. They are characterized by dense formations, strong heterogeneity, and the low natural productivity of individual wells, making well pattern deployment and injection–production parameter optimization highly challenging. In real development, tight oil and gas fields usually involve hundreds or even thousands of wells. If each well is analyzed and optimized individually, a large amount of computation is required. Meanwhile, uncertainty in geological models further increases the complexity of development scheme design. Traditional manual adjustment methods based on engineering experience are inefficient and make it difficult to obtain an optimal well pattern suitable for the efficient development of tight oil and gas reservoirs under complex constraints, thus showing obvious limitations. To address these problems, this study first analyzes the strengths, weaknesses, and applicability of existing well placement optimization methods. Based on this analysis, we propose an optimization design method that integrates numerical simulation software for tight oil and gas reservoirs with modern intelligent optimization algorithms, enabling rapid and effective integrated optimization of horizontal well placement and fracturing in tight reservoirs. After being applied to Block X of a tight oil field, this optimization method achieved favorable field results, with an average cumulative oil and gas equivalent production of 31,400 metric tons per well, providing a new approach for the effective development of similar tight oil and gas reservoirs. Full article

Characterizing the human health risk posed by constituents in drinking water is often challenging due to a lack of published toxicity values. The PIANO (Paraffin, Isoparaffin, Aromatic, Naphthene, and Olefin) analytical method measures nearly 300 compounds in JP-5 jet fuel, 43 of which have published oral reference doses (RfDs). The remaining compounds are typically assigned surrogate toxicity values. We predict RfDs for 290 PIANO compounds using Quantitative Structure–Activity Relationship (QSAR) models based on stepwise linear regression of 2-dimensional molecular descriptors (MDs) and published toxicity values. Five training groups, created by randomly selecting 80% of the non-PIANO compounds and 50% of the 43 PIANO compounds that have RfDs within a master dataset of 1113 compounds, were used to develop five QSAR models. We used the geometric means of four QSAR model results of sufficient quality to predict RfDs for compounds lacking toxicological information. For compounds with known RfDs, 884 (79%) were within 8-fold of published RfDs, well within the acknowledged uncertainty inherent in published RfDs. Our approach has applicability beyond PIANO compounds and represents a new alternative methodology (NAM) that may be used to reduce uncertainty in human health risk assessment and guide regulatory decisions. Full article

In gas-condensate reservoirs, the phase behavior of reservoir fluids is inherently dynamic during pressure depletion. When the rate of external pressure decline exceeds the intrinsic relaxation rate governing phase equilibrium, the system deviates from thermodynamic equilibrium and exhibits pronounced non-equilibrium effects. These transient behaviors significantly influence fluid properties; meanwhile, conventional equilibrium models neglect phase transition lag, resulting in inaccurate phase behavior and biased production predictions. In this study, a non-equilibrium dynamic phase transition model is developed to quantitatively couple the pressure depletion rate with the relaxation kinetics of the system. This model, established based on controlled non-equilibrium phase transition experiments performed on the condensate-gas fluid investigated in this work, provides an analytical framework for describing the temporal evolution of phase behavior under dynamic conditions. Model validation through integrated experimental measurements and numerical simulations shows good agreement between calculated and measured results for the studied condensate-gas system, with average relative errors below 5%. Results reveal that accelerated pressure depletion strengthens non-equilibrium effects. At a rate of 15 MPa/h, the relative volume and retrograde condensate saturation decrease by 9.09% and 5.38%, respectively, while condensate recovery improves by 13.85%. Moreover, the characteristic relaxation time toward equilibrium exhibits a strong dependence on the depletion rate, increasing as the depletion rate rises. This work provides an experimentally constrained analytical framework for describing rate-dependent non-equilibrium phase behavior during pressure depletion and for interpreting its impact on condensate recovery in the specific condensate-gas system studied. Although the governing framework may be transferable to other rate-sensitive hydrocarbon systems after fluid-specific recalibration, the parameterized analytical model and validation presented in this study are limited to the investigated condensate-gas fluid, and its applicability to other hydrocarbon fluid types remains to be evaluated in future studies. Full article

This Communication reports limited engineering screening data on polymer liner candidates for flexible composite pipes used in oil and gas service. Three exposure conditions were considered: hydrothermal aging in superheated water, thermal-oxidative aging in dry air, and hydrocarbon-medium exposure. Superheated-water immersion for up to 1000 h, dry-air aging for 168 h, and 7-day hydrocarbon exposure were used to describe changes in tensile properties, Shore hardness, mass, and thickness. Complete replicate records were available only for the thermal-oxidative aging dataset; therefore, most hydrothermal and hydrocarbon-medium results are reported as descriptive summary data. In the recorded data, EPDM formulation CL-2-1 retained approximately 89% of its tensile strength after 1000 h in superheated water. Sample L showed a smaller mean tensile-strength decrease than Sample Z after 168 h at 150 °C in dry air. In the hydrocarbon-medium summary data, XL95A/05B-S1 showed lower mass increase and smaller tensile-strength and yield-stress decreases than PERT XRT70H across the tested temperature range. The Communication provides case-specific screening evidence and identifies the need for replicated testing, statistical analysis, longer aging series, and structural characterization before general material-selection or durability conclusions are made. Full article

The Late Triassic Bolila Formation in the central Qiangtang Basin is a typical carbonate buildup deposited during a regional transgression in the eastern Tethyan realm. Understanding its sedimentary evolution and reservoir-forming mechanisms is crucial for hydrocarbon exploration. This study integrates petrology, detrital zircon U-Pb geochronology, carbon-oxygen isotopes, and reservoir property analysis of the Quemudongda section. The results show: (1) detrital zircon dating provides a maximum depositional age of 225.7–235.7 Ma (Carnian–Norian), correcting the previous Jurassic misassignment on the 1:250,000 geological map. Carbon-oxygen isotopes (average δ¹³C = +3.2‰, δ¹⁸O = −11.1‰) are consistent with the global Carnian–Norian positive δ¹³C excursion. (2) The section reveals a platform-margin reef (hexactinellid and calcareous sponges) and slump breccia (seven layers) association, representing a steep-rimmed carbonate platform margin. The sedimentary evolution comprises three stages: reef initiation, reef flourishing with frequent slumping, and reef decline with dolomitization. (3) Reservoirs are mainly breccia and reef dolostones, with intergranular, intercrystalline, and fracture-related pores. Porosity averages 2.8% (0.8%–7.2%), permeability averages 0.35 mD (0.001–8.5 mD), defining a low-porosity, ultra-low-permeability fracture-pore reservoir. Breccia dolostone has better properties (porosity 3.71%, permeability 2.412 mD). (4) Reservoir formation is controlled by sedimentation (platform-margin facies), diagenesis (dolomitization generates pores, but high-temperature recrystallization causes densification), and tectonics (microfractures enhance permeability). High-quality reservoirs occur where breccia dolostone and fractures overlap. (5) The Bolila reef-shoal complex and the overlying Bagong Formation source rocks form a “lower reservoir—upper source” assemblage, representing a new exploration target in the Tuonamu area. The breccia dolostone–fracture overlap zone is the core “sweet spot”. Full article

The pyrolysis of polypropylene (PP) microplastics offers a potential route to convert plastic waste into fuel-range hydrocarbon mixtures and chemical feedstocks. However, the elementary radical pathways underlying the formation of medium-chain hydrocarbon fragments remain insufficiently resolved. In this study, a representative isotactic PP oligomer model (C₄₅H₉₂) was evaluated using a comparative density functional theory (DFT) framework. The main mechanistic analysis was based on M06-2X, ωB97X-D, and M11 calculations combined with the def2-TZVP basis set, whereas LANL2DZ was retained only as a lower-cost comparative level during reaction-pathway exploration. Thermochemical profiles were evaluated over a temperature range of 298–923 K. Three selected pathways involving mid-chain homolytic cleavage, intramolecular hydrogen transfer (backbiting), radical rearrangement, and β-scission were examined. Within the selected reaction set, Route 1 exhibited a comparatively more favorable thermochemical profile than Routes 2 and 3 and provided a mechanistically plausible sequence toward medium-chain hydrocarbon fragments. The −TΔS contribution strongly influenced the calculated Gibbs free-energy profiles because fragmentation increases the number of molecular species under the ideal-gas thermochemical approximation. Accordingly, the ΔG values were interpreted comparatively and were not treated as direct evidence of spontaneous fragmentation under condensed-phase pyrolysis conditions or as quantitative predictions of experimental product selectivity. Differences among the evaluated functionals further indicate that the relative description of radical intermediates and transition-state regions is method-dependent. These results provide a molecular-level framework for future studies integrating quantum-chemical calculations, microkinetic modeling, and experimental product characterization. Full article

The consumption of vegetable oils is steadily increasing, especially in Asian countries. Once used, the utilized cooking oils are either thrown into landfills or dumped there, endangering both the environment and people. One common method is to convert waste cooking oil (WCO) into biofuel; however, since WCO contains many free radicals, burning it releases large quantities of pollutants, meaning that disposal of WCO poses significant environmental risks. To stabilize the WCO (Cocos nucifera) before converting it into biofuel, this study analyzed the extraction, optimization, and use of antioxidant-rich bio-oil from Anisomeles malabarica leaves as a natural additive. Solvent screening revealed that a hexane–ethanol ratio of 4:2 was optimal for generating 76.7% bio-oil at room temperature. A maximum yield of 77% was attained by temperature and time optimization, which determined that 50 °C and 20 min were ideal. The extraction exhibits zero-order kinetics during the increasing phase, according to kinetic studies, with rate constants ranging from 0.54 to 1.44% min⁻¹ (R² = 0.950–0.997). The Peleg equilibrium model (average R² = 0.806) was used to describe the extraction profile. The regression equation ln(k) = 1799.3 × (1/T) − 10.828 (R² = 0.9748, p = 0.0002) was obtained using Arrhenius analysis. It was found that the compounds responsible for the antioxidant scavenging activity were found to be phytol, hexadecenoic acid, and tocopherol (vitamin E). The DPPH (2,2-diphenyl-1-picrylhydrazyl) test confirmed that 3% (v/v) bio-oil scavenged about 95% of free radicals, whereas the conjugated diene experiment demonstrated that over 90% of lipid oxidation in WCO was prevented. The combustion and emission properties of biofuel (WCB), which was created by transesterifying bio-oil-treated WCO, were compared to those of neat diesel and untreated WCO-derived biofuel (WC). In comparison to both WC50 and neat diesel, WCB50 demonstrated an equivalent in-cylinder pressure and heat release rate, but significantly reduced emissions of NO_x, CO, hydrocarbons, and smoke. These results show that Anisomeles malabarica bio-oil works well as a natural antioxidant addition for clean combustion and biodiesel stabilization. Full article

Introduction: Temperature is a key environmental factor influencing the physiological and biochemical processes of aquatic organisms, including xenobiotic metabolism. Understanding how temperature modulates the toxicological effects of pollutants such as polycyclic aromatic hydrocarbons (PAHs) is crucial in the context of climate change. Among these compounds, benzo[a]pyrene (BaP) and benzo[a]anthracene (BaA) are priority pollutants in aquatic environments, resulting from incomplete combustion. Their relevance is attributed to persistence and metabolic bioactivation potential. Fish primary hepatocyte cultures represent a relevant in vitro model for studying combined effects of thermal stress and chemical exposures, while supporting the 3Rs principles (Replacement, Reduction, and Refinement). Objective: This study aims to assess temperature-dependent effects of BaP and BaA, and their mixtures in brown trout hepatocytes using cytochrome P450 1A (CYP1A) immunohistochemistry as an indicator of xenobiotic metabolism. Methodology: Primary hepatocytes were isolated using a two-step collagenase perfusion method and cultured in 24-well plates at 18 °C and 22 °C. Cells were exposed for 72 h to supplemented L-15 medium (control) or to 0.1% dimethyl sulfoxide in supplemented L-15 medium (solvent control), as well as to single exposures of 1 and 10 µM of BaP and BaA and to equimolar mixtures of both compounds (1 and 10 µM). Viability was assessed using the lactate dehydrogenase (LDH) assay. CYP1A immunostaining was quantified based on cytoplasmic staining intensity relative to background area. Results: No significant effects on cell viability were observed under any condition. Temperature significantly reduced CYP1A expression in single exposures at 22 °C compared to 18 °C. BaP induced a significant dose-dependent increase, while BaA differed from controls only at 10 µM. In mixtures, only treatment- and dose-dependent effects were observed, with no temperature influence detected. Conclusions: Overall, the data highlight temperature as a key modulator of biochemical responses to PAHs, with single and mixed exposures eliciting distinct effects and suggesting potential synergism in mixtures. Full article

Introduction: The temperature of rivers in the Iberian Peninsula has increased due to global warming. In addition, these rivers are polluted by contaminants of emerging concern, such as polycyclic aromatic hydrocarbons (PAHs). Higher temperatures and pollution concurrently impose threats to the Iberian Peninsula’s endemic species, including the brown trout (Salmo trutta), a cold-water species widely used in ecotoxicological studies. Because the liver is the main biotransformation organ, and is particularly sensitive to both chemical and temperature changes, in vitro liver models may represent valuable alternatives for assessing combined stressor effects, complying with the 3Rs principle. Objective: In line with the above, the present study aimed to evaluate the combined effects of a 4 °C temperature increase and the model PAH benzo[k]fluoranthene (B[k]F) on fish liver cells using a primary brown trout hepatocyte culture as a model. Methodology: Primary hepatocytes were seeded in 6-well plates at a density of 1.0 × 10⁶ cells/mL and exposed for 48 h to 1, 10, and 20 µM B[k]F at 18 °C (normothermia) and 22 °C (warming scenario). Cell viability was assessed using trypan blue, alamarBlue, and lactate dehydrogenase (LDH) assays. Cytochrome P450 (CYP)1A was evaluated in terms of its gene expression by RT-qPCR and its protein expression through immunocytochemistry (ICC). The immunostaining was quantified using a score system which considered five intensity staining levels. Results: Exposure to B[k]F and to the higher temperature increased LDH leakage without interaction effects. In contrast, the other viability assays did not show significant differences across conditions. Regarding CYP1A, both gene and protein expression increased with all B[k]F concentrations in relation to the controls, but were not influenced by temperature. Notably, the lowest B[k]F concentration (1 µM) elicited the highest CYP1A gene expression, suggesting a non-monotonic response. Conclusions: Overall, the model was responsive to both temperature (4 °C) increase and to B[k]F, validating its usefulness for assessing liver pollutant effects in the context of global warming. These findings support the application of fish primary hepatocyte models as relevant tools in ecotoxicology under environmentally realistic multi-stressor scenarios. Full article