Search Results (28,533)

Recalcitrant azo dyes in textile wastewater are a significant environmental concern due to their persistence and potential impacts on human and ecosystem health. Heterogeneous Fenton-like processes offer a promising approach for their removal, although catalyst performance depends strongly on the physicochemical characteristics of the active material. This study investigated Fe-functionalized silicon oxide (Fe-SiO) catalysts for sodium percarbonate (SPC)-activated removal of Reactive Orange 84 (RO84). The catalysts were prepared using silicon oxide supports with and without thermochemical pretreatment and different amounts of Fe during synthesis. Their structural, morphological, and elemental characteristics were evaluated by transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS), complemented by textural analysis. Increasing the amount of Fe used during synthesis shifted removal from adsorption-influenced to oxidation-associated, as reflected in the kinetic behavior. Thermochemical pretreatment promoted more homogeneous Fe dispersion and reduced aggregation in the S2 series, consistent with its higher catalytic response under several evaluated conditions. The PFO model empirically described the observed removal kinetics. Overall, the Fe-SiO materials showed potential for SPC-assisted RO84 removal under the evaluated conditions. Full article

Laser-induced graphene (LIG) has great potential for multiple applications because of its large specific surface area, facile fabrication process, and tunable properties. However, abundant lattice defects severely degrade its conductivity. Herein, from an innovative perspective of precursor design, the poly-phenylamines (P-PAs) with improved solubility and strong light absorption were synthesized, which act as an intercalated polymer for graphene oxide (GO) nanosheets. On this basis, the composite precursors show remarkably enhanced photothermal conversion capability and a compact stacked structure. These bring a 60% reduction in I_D/I_G in LIG after laser irradiation. To explain the above phenomenon, an isolation effect induced by the compact stacking precursor is proposed based on experimental results. Furthermore, the cooperative effect between P-PAs and Fe²⁺ is introduced, and a fluffy LIG aerogel with the lowest I_D/I_G ratio of 0.17 is prepared, which is barely achievable in conventional LIGs. When the obtained graphene aerogel is compounded with PDMS, the as-prepared thermal-conductive composite gel reaches a thermal conductivity of 1.05 W·m⁻¹·K⁻¹ and an ultralow interfacial thermal resistance of 37.2 mm²·K·W⁻¹ under a low graphene loading of 3.3 wt%. This intercalation strategy in GO precursor supplies a new route for preparing high-quality LIGs and thermal-conductive gels, which show great application prospects in thermal management devices. Full article

Industrial effluents containing persistent synthetic dyes represent an important environmental challenge because of their high chemical stability, low biodegradability, and potential adverse effects on aquatic ecosystems. This study evaluates electrochemical advanced oxidation processes (EAOPs) as remediation strategies for dye-contaminated tanery dyes, with particular emphasis on conditions representative of complex industrial effluents. Electrochemical oxidation (EOx), electro-Fenton (EF), and photoelectro-Fenton (PEF) processes using boron-doped diamond (BDD) electrodes were comparatively investigated for the degradation of Violet S4B and a multicomponent mixture containing Violet S4B, Brown DR, and Black NT2. The effects of current density and pollutant concentration were assessed through discoloration, pseudo-first-order kinetics, chemical oxygen demand (COD) removal, and HPLC analysis of oxidation intermediates. For the multicomponent system, PEF achieved approximately 99% discoloration after 120 min, compared with nearly 97% for EF and 95% for EOx, with apparent rate constants increasing in the order EOx < EF < PEF. More importantly, COD analysis demonstrated extensive mineralization during PEF treatment, while HPLC revealed negligible accumulation of oxalic acid, indicating effective oxidation of refractory intermediates. The results demonstrate that combining anodic oxidation, electrochemically generated Fenton chemistry, and photo-assisted reactions enhances the remediation of complex dye mixtures. These findings support BDD-based EAOPs, particularly PEF, as promising technologies for reducing persistent organic pollution associated with tannery dye solutions. Full article

Background/objectives: Perinatal hypoxia–ischemia (HI) is a major cause of brain injury and is associated with long-term neurological impairments, including white matter injury, astrogliosis, microgliosis, and hypomyelination. Maternal exercise has emerged as a potential non-pharmacological strategy to improve fetal development and increase resilience to prenatal insults. This study investigated whether maternal exercise during pregnancy protects against neuroglial alterations in the corpus callosum of offspring subjected to prenatal HI. Methods: Adult female Wistar rats were assigned to sedentary or exercise groups. The exercise protocol consisted of daily swimming sessions with progressive durations (3–30 min/day) over 10 days. Blood glucose levels and oxidative stress markers (GSH, TBARS, and DPPH) were evaluated to characterize the physiological effects of the protocol. Prenatal HI was induced on gestational day 18 by transient occlusion of the uterine arteries for 45 min, whereas sham-operated dams underwent identical surgical procedures without arterial occlusion. Offspring were euthanized on postnatal days (P) 16 and 23, and brain sections were processed for immunohistochemistry using antibodies against glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP). Images were quantitatively analyzed using Image-Pro Plus, and statistical analyses were performed using SPSS software. Results: The exercise protocol did not show oxidative stress, hypoglycemia, or exhaustion. Female offspring from HI group exhibited astrogliosis at P16, which persisted until P23; however, maternal exercise prevented this response at P23. No changes in MBP immunoreactivity were detected in females. Male offspring did not develop astrogliosis but displayed hypomyelination at P23, which was prevented by maternal exercise. Conclusion: These findings demonstrate that maternal exercise during pregnancy attenuates sex-dependent neuroglial alterations induced by prenatal HI, supporting its potential as a preventive strategy to reduce white matter injury and improve neurodevelopmental outcomes. Full article

Understanding microbial community assembly mechanisms in aquatic habitats is fundamental to predicting ecosystem responses to environmental change, yet systematic comparisons of deterministic versus stochastic process contributions among different water types remain limited. We conducted monthly sampling over one year from four freshwater habitats, including two aquaculture ponds (WC01, WC02), an enclosed urban lake (TZ), and a flowing river (XJ), and applied a phylogenetic-bin-based null model framework to uncover how bacterial community assembly processes change among habitats and time/season. The results indicated that homogeneous selection (33.5%), dispersal limitation (31.0%), and drift (26.5%) jointly governed community assembly across all samples. Among the four investigated systems, water type, rather than season or their interactions, emerged as the primary factor regulating assembly process differentiation. Specifically, homogeneous selection was significantly stronger in the two aquaculture ponds (WC01, WC02) than in the natural water bodies (TZ and XJ), while the flowing river XJ exhibited the highest dispersal limitation and the lowest drift. At the phylogenetic bin level, over 98% of bins switched their dominant assembly strategies across the four water bodies, especially between the two aquaculture ponds and the two natural water bodies. Environmental factor analyses also revealed habitat-specific driving patterns: nitrogen and phosphorus nutrients dominated homogeneous selection in the aquaculture ponds, whereas dissolved oxygen, turbidity and oxidation reduction potential mainly regulated dispersal limitation in the natural waters. Collectively, these findings reveal a hierarchical pattern of freshwater bacterial assembly with multi-process coordination, habitat dominance, and lineage-level differentiation, and underscore that lineage-level analyses are essential for uncovering assembly patterns hidden at the community level, offering practical guidance for microbial management under diverse hydrological conditions. Full article

Synthesis of multilayer graphene oxide (GO) was achieved through a Hummers method with meticulous control over the addition of the oxidizing agent. Precursors were immersed in an ice bath during the synthesis to maintain a temperature of approximately 275 K in oxidation stages I and II, temperature was measured with a thermocouple inside the cooling bath, in direct contact with the vacuum filter flask at the level of the reactants. In contrast to the variety of Hummers synthesis methods—where the system is maintained at certain temperature during the initial oxidation stage and heat continues to be supplied during the second stage—our setup operates at low temperature from the beginning to the conclusion of the process. A detailed analysis of the compositional, structural, and optical properties of the fabricated GO was conducted, revealing a notable photoluminescent band in the 380–480 nm region. This property is of interest for a potential future application in the field of optoelectronics. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) revealed that the structure of the material consists of a sp³ matrix with sp² domains. Raman spectroscopy revealed an I_D/I_G ratio of 2.7, which could indicate a high density of structural defects or extremely small sp² graphitic domains. Furthermore, deconvolution of the 2D band suggests the presence of multilayers in the GO. Fourier transform infrared spectroscopy (FTIR) analysis revealed the presence of all functional groups associated with the GO. Upon observation of the photoluminescence exhibited by the material, a broadband centered on the violet-blue emission, with a possible mechanism consistent with the literature associated with the transitions between sp² domains and localized states in the basal plane defects or it might be caused by quantum confinement effects. The diminished contribution from the green emission could be caused by the transitions between localized states sp² and the functional groups associated with oxygen. Full article

Background: Lung adenocarcinoma (LUAD) is the most common subtype of non-small-cell lung cancer and is one of the leading causes of cancer-related deaths globally. Despite current developments, reliable biomarkers for effective diagnosis, prognosis, and patient stratification are still lacking. Methods: We analyzed publicly available TCGA-LUAD and GEO datasets using integrative bioinformatics approaches, including differential gene expression, weighted gene co-expression network analysis (WGCNA), survival modeling, mutation profiling, immune cell infiltration scores, machine learning, and bulk-RNA and single-cell RNA sequencing. Results: A total of 5581 deregulated genes were identified, with the turquoise module (298 genes) showing strong correlation with LUAD (Corr = −0.79, p < 2.2 × 10⁻³⁰⁸). The integration of two analyses yielded 281 overlapping genes, out of which nine candidates (ANO2, CHIAP2, CPED1, DNASE1L3, GSTM5, HTR3C, PRKCE, SLC14A1, and WNT3A) were selected via LASSO Cox regression to build a prognostic risk model. High-risk patients have significantly worse survival (log-rank p = 0.0027). CPED1 exhibited the highest mutation frequency, with 41% of TCGA-LUAD samples harboring mutations. Among all CPED1 mutation events, missense mutations were the most common (47%). GSEA and KEGG analysis revealed significant enrichment of pathways such as nucleocytoplasmic transport, oxidative phosphorylation, protein processing in the endoplasmic reticulum, ribosome, and ribosome biogenesis in high-risk patients. Immune infiltration analysis indicated differences in immune cell infiltration scores between high- and low-immune-score groups, with M1 macrophages showing strong statistical correlation with aDC, monocytes, and CD4⁺ naïve T cells. Machine learning confirmed that the combined Enet+PLS model predicted CPED1 as a core predictor, and CPED1 was successfully validated in independent GEO datasets (GSE43458 and GSE31210), showing strong diagnostic accuracy (AUCs up to 0.98). Finally, single-cell RNA sequencing revealed that CPED1 was mostly expressed in fibroblasts and myeloid cells, with CPED1 significantly downregulated in LUAD compared with normal samples. Conclusions: This study integrates multi-omics and machine learning to highlight CPED1 as a promising candidate biomarker, with potential diagnostic and prognostic relevance in LUAD. The nine-gene risk signature stratified patients by survival outcomes in the TCGA cohort. Genomic and immune analyses revealed features associated with the high-immune-score group. As the study is entirely computational and the prognostic model lacks external survival validation, these findings should be regarded as preliminary and hypothesis-generating, requiring future independent validation and functional studies to confirm the biological significance and clinical utility of CPED1 and related genes. Full article

Citrus processing by-products represent a sustainable source of bioactive plant complexes with potential applications in intestinal health. This study investigated the effects of standardized food-grade orange (OE) and lemon (LE) pomace extracts and their simulated gastrointestinal digestates (DIGs) on intestinal epithelial responses and selected probiotic strains. Caco-2 cells were used to assess cytotoxicity, epithelial wound closure, and, in differentiated monolayers challenged with lipopolysaccharide (LPS), extracellular levels of SOD2, catalase, Nrf2, IL-6, IL-8, TNF-α, and IL-1β. In parallel, the effects of OE, LE, and their corresponding DIGs on the growth and cell-surface hydrophobicity of four probiotic lactic acid bacteria were evaluated. OE and LE DIGs were non-cytotoxic and promoted epithelial wound closure in a concentration- and time-dependent manner. In LPS-challenged monolayers, both DIGs counteracted alterations in extracellular oxidative stress-related proteins and reduced pro-inflammatory cytokine levels without affecting cell viability. OE and LE also produced strain-dependent effects on probiotic growth and cell-surface hydrophobicity, which were modified by gastrointestinal digestion. Overall, these findings extend previous evidence on the intestinal bioactivity of Citrus pomace-derived plant complexes and support their further investigation as sustainable food-grade ingredients for gut health applications. Full article

Ethyl mercaptan is one of the most persistent sulfur-containing impurities in natural gas and requires efficient adsorbent/catalyst systems for removal under mild conditions. In this study, two types of halloysite-supported metal oxide catalysts, namely Mn- and Cu-based catalysts, were prepared via reflux-wet impregnation using three alkaline precipitation agents (NaOH; Ca(OH)₂; Ba(OH)₂), with and without the use of acetic acid added during the synthesis process. The objective was to evaluate how acidic and alkaline synthesis environments influence catalyst structure, surface chemistry, active metal distribution, and ethyl mercaptan adsorption performance. Characterization techniques used to examine the catalysts included Brunauer–Emmett–Teller surface area analysis (BET), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The characterization results showed that halloysite (support) possessed a mesoporous structure with a surface area of 51.2 m²/g, while metal incorporation modified the pore structure, surface composition, crystallinity, and morphology of the support. Acid addition during synthesis produced base-dependent effects: it improved the textural properties of Mn-Ca(OH)₂ and Cu-NaOH catalysts but generally reduced active metal surface concentration, modified hydroxyl environments, and increased structural disorder in several systems. XRD and XPS studies suggested that Cu catalysts were comprised primarily of well-defined CuO/Cu₂O surface domains, while Mn catalysts were mostly amorphous or poorly crystallized MnO_x species. Adsorption testing using 200 ppm ethyl mercaptan in methane demonstrated that several synthesized catalysts significantly outperformed the commercial catalyst, which showed a breakthrough time of approximately 1200 min. The best Mn catalyst was Mn-Ba(OH)₂ synthesized without acid, reaching approximately 3600 min. The Cu catalysts showed superior performance overall, with Cu-Ca(OH)₂ synthesized without acid achieving the highest breakthrough time of approximately 8550 min, corresponding to more than a six-fold improvement over the commercial catalyst. These findings demonstrate that catalyst performance is governed not by surface area alone, but by the combined effects of active metal chemistry, precipitation environment, surface composition, crystallinity, metal–support interactions, and accessibility of adsorption-active sites. Full article

To investigate the corrosion resistance and service life of water-based epoxy-coated reinforcing bars under severe environmental conditions, HRB400 ribbed reinforcing bars were used as the substrate. Four types of water-based epoxy-coated reinforcing bars were prepared, containing 0.3% graphene–polyaniline (PAG), 0.3% iron oxide, 10% zinc phosphate, and 10% zinc–iron powder, respectively, with a bare reinforcing bar control group also included. In accordance with standards such as the ‘Design Standard for Durability of Concrete Structures’, durability tests were conducted under various conditions, including long-term immersion in marine chloride solutions, wet–dry cycling, de-icing salt freeze–thaw cycles, baking and immersion in saline soil, and concrete mixed with seawater. Corrosion current density (I_corr) was monitored using a three-electrode system and the linear polarisation method, and service life was predicted based on the Wiener process. The results indicate that, under all severe environmental conditions, the corrosion current density of the coated reinforcing bars was significantly lower than that of the bare reinforcing bars (BRBs). After 70 cycles of marine wet–dry cycling, the corrosion current density of the bare reinforcing bars reached 0.4569 μA·cm⁻², whilst that of the 0.3% PAG coating was 0.1103 μA·cm⁻², substantially lower than that of the bare bars (0.4569 μA·cm⁻²); after 110 freeze–thaw cycles in a de-icing salt environment, the corrosion current density of the bare reinforcing bars was 0.4480 μA·cm⁻², whilst that of the PAG-coated bars was 0.1003 μA·cm⁻². After 80 cycles of baking and immersion in a saline soil environment, the corrosion current density of the graphene–polyaniline-coated steel increased from 4.97 × 10⁻³ μA·cm⁻² to 0.1021 μA·cm⁻² (approximately a 20-fold increase), whilst that of the bare steel rose to 0.4489 μA·cm⁻². In concrete mixed with seawater, the corrosion current density of bare reinforcing bars reached as high as 8.60 μA·cm⁻² after 120 days, whereas that of coated reinforcing bars was 0.24 μA·cm⁻², markedly lower than 8.60 μA·cm⁻² for the bare bars. Lifespan predictions indicate that, provided that the specifications for concrete strength and protective layer thickness are met, water-based epoxy coatings have the potential to delay the onset of severe corrosion (I_corr ≥ 1 μA·cm⁻²) beyond the 50-year design threshold in seawater wet–dry cycling zones and saline soil environments, and are projected to meet the 100-year design requirements in de-icing salt environments. It should be noted that these projections are based on accelerated tests and require validation through long-term field performance data. Graphene-containing polyaniline nanocomposite coatings exhibited the best overall protective performance, whilst zinc phosphate coatings demonstrated outstanding stability in high-chloride environments. For the specific formulations tested in this study, the enhanced corrosion resistance is attributed to the synergistic combination of the epoxy matrix, inorganic fillers (TiO₂ and BaSO₄) and functional additives; these components collectively provide physical shielding, chemical passivation and dynamic pore-blocking effects. Within the scope of this study, the nanocomposite coating containing 0.3 per cent PAG exhibited the best overall protective performance. Full article

Silica aerogels are among the most extraordinary porous materials produced through sol–gel chemistry, distinguished by ultralow density, exceptionally high porosity, large specific surface area, and extremely low thermal conductivity. Despite these characteristics, widespread application of conventional silica aerogels has been constrained by inherent brittleness, poor mechanical strength, and moisture sensitivity. Significant research has therefore focused on silica aerogel composites, in which reinforcing or functional phases—fibers, polymers, carbon nanomaterials, metal oxides, and biopolymers—are integrated into the silica network to enhance mechanical robustness, flexibility, hydrothermal stability, electrical conductivity, catalytic activity, and multifunctionality while largely preserving the parent aerogel’s desirable properties. We review the synthesis, characterization, properties, and applications of silica aerogel composites. Sol–gel processing and drying technologies are discussed, followed by composite-formation strategies and the advanced techniques used to evaluate structural, mechanical, thermal, surface, and functional properties. The effects of reinforcing phases on mechanical performance, thermal conductivity, and hydrothermal stability are analyzed, and current and emerging applications in thermal insulation, environmental remediation, catalysis, acoustic damping, aerospace systems, biomedical engineering, and energy storage are highlighted. Finally, key challenges and future directions involving multifunctional materials, green synthesis, and data-driven materials design are discussed. Full article

The methanation of pyrolysis gas was investigated using the open access software DWSIM v9.0.5 to assess its potential for producing methane-rich gas. The pyrolysis gas composition was derived from known experimental tests of anthropogenic residues, namely sewage sludge and digestate. Four gas compositions were considered; they were obtained by the pyrolysis of residues with and without a sorbent for CO₂ capture. The methanation process was simulated by a non-stoichiometric thermodynamic approach to calculate the chemical equilibrium composition of the gas. A parametric investigation was carried out under a temperature range of 300–500 °C and a pressure range of 10–40 bar. Carbon oxide conversion, methane selectivity and methane yield were calculated. CO almost underwent quantitative conversion, while CO₂ showed significantly lower or negative conversion. Synthetic biogas was obtained from the pyrolysis gas of the residues, showing a methane content of about 50 mol%. Synthetic natural gas was obtained from the pyrolysis gas residues plus sorbent, showing a methane content of about 90 mol%. Full article

Malachite green (MG), a triarylmethane dye extensively used in the textile and aquaculture industries, is a persistent aquatic contaminant with documented carcinogenic, mutagenic, and teratogenic effects even at trace concentrations. In the present work, a natural, low-cost Serpentine clay was surface-modified with copper oxide nanoparticles generated in situ through a green, lemon-extract-mediated reduction of copper nitrate, yielding a novel SER/CuO nanocomposite. The as-prepared adsorbent was characterized by FTIR, XRD, BET, and SEM to confirm the successful anchoring of CuO nanoparticles onto the Serpentine lattice. Batch adsorption experiments demonstrated that the removal of MG was governed by solution pH, adsorbent dose, contact time, and initial dye concentration, with maximum uptake obtained close to neutral pH, consistent with the point of zero charge (pH_pzc = 7.6) of the composite relative to the pKa (6.9) of the dye. Equilibrium data were described comparably well by the Langmuir and Freundlich isotherms at 25 and 55 °C, with a maximum monolayer capacity of 279.06 mg g⁻¹ at 25 °C, while kinetic analysis showed the closest statistical agreement with the Elovich model, pointing to an energetically heterogeneous, chemisorption-assisted process supported by a three-stage intraparticle-diffusion profile. The individual and combined effects of solution pH, adsorbent dose, and contact time on removal efficiency were systematically evaluated using a one-factor-at-a-time approach. Thermodynamic estimation from the two-temperature Langmuir constants indicated a spontaneous and exothermic, and entropy-favored adsorption process. The spent adsorbent was regenerated using dilute hydrochloric acid and retained appreciable efficiency over successive cycles. Comparison to previously reported adsorbents supported the competitiveness of SER/CuO in terms of capacity, cost, and simplicity of preparation, and a techno-economic appraisal supported the feasibility of scale-up. As a waste-valorization step, both the bare SER/CuO adsorbent and its MG-loaded form were evaluated as electrode materials for the urea oxidation reaction: MG loading raised the anodic current density from 143.10 to 176.46 mA cm⁻² at 1.0 M urea, nearly doubled the electrochemically active surface area (7.34 to 14.41 cm²), and lowered the charge-transfer resistance, while sustaining a higher stable current density (111 vs. 81 mA cm⁻²) over 3600 s of continuous operation demonstrating a promising route for coupling water remediation with energy recovery. Full article

Pecan oil is a valuable source of unsaturated fatty acids and bioactive compounds whose recovery and stability may be influenced by the extraction process. This study compared Soxhlet extraction (SE), ultrasound-assisted extraction (UAE), and supercritical CO₂ extraction (sCO₂) in terms of extraction yield, fatty acid profile, physicochemical properties, total phenolic content (TPC), antioxidant activity, and oxidative stability. SE achieved the highest extraction yield (69.21%), followed by sCO₂ (52.89%) and UAE (48.68%). The fatty acid profile was relatively stable among extraction methods, although differences were observed in the relative proportions of oleic and linolenic acids. UAE produced oil with the highest TPC (32.55 µg GAE/g oil), whereas sCO₂ showed the highest initial antioxidant activity (2681 µmol TE/100 g oil). After 12 days, UAE oil exhibited the lowest peroxide value (10.49 meq O₂/kg) and the highest TPC retention, whereas sCO₂ oil showed the greatest peroxide accumulation (28.16 meq O₂/kg) and the largest decrease in TPC. These results demonstrate that extraction conditions differently affect oil recovery, antioxidant-related properties, and oxidative stability. Under the conditions evaluated, UAE showed particular advantages in preserving TPC and limiting primary oxidation during accelerated storage, despite its lower extraction yield. Full article

Wastewater treatment systems are under increasing pressure to improve nitrogen removal while reducing carbon emissions, yet the deployment of anaerobic ammonium oxidation (anammox) remains constrained by uncertainty about technical readiness, operational robustness, nitrous oxide (N₂O) emissions, life-cycle carbon performance, monitoring capacity, and transferability across wastewater contexts. This study uses dynamic topic modelling and trend assessment of 998 publications from 2001 to 2025 to synthesize deployment-relevant evidence for anammox-based wastewater treatment. The results indicate that the field has shifted from reactor start-up and process-parameter optimization toward microbial regulation, mainstream process integration, coupled nitrogen-removal strategies, and intelligent control. Building on these topic-evolution patterns and reported engineering evidence, this study provides an evidence-based qualitative appraisal of deployment-readiness signals and evidence gaps, distinguishing comparatively mature side-stream applications from mainstream systems that still require monitored demonstrations, transparent N₂O accounting, life-cycle assessment, and locally validated operating data. The study argues that anammox should be evaluated as a technology with potential but conditional carbon-saving benefits: its potential carbon-saving benefits depend on operational evidence specific to each application stage, carbon-accounting credibility, and implementation capacity, rather than assuming that research activity alone justifies broad deployment. Full article