Search Results (3,362)

Background/Objectives: Spinal osteoarthritis (sOA) is a degenerative condition marked by pain, inflammation, and restricted mobility. While surgical interventions such as spinal decompression and stabilization are common, their impact on redox status and inflammatory markers remains underexplored. This study aimed to assess the effects of surgery on clinical, hematological, biochemical, and redox parameters in patients with sOA. Methods: A total of 25 patients diagnosed with sOA underwent spinal decompression and stabilization surgery. Preoperative and postoperative assessments included hematological and biochemical analyses, redox status evaluation (TAS, TOS, GSH, AOPP, SOD), and inflammatory markers such as IL-6. Disease severity was graded using the Kellgren–Lawrence (K-L) system. Results: Postoperatively, there was a significant decrease in neutrophil count (p = 0.014) and AOPP levels (p < 0.001), with a corresponding increase in lymphocyte count (p = 0.016), erythrocyte count (p = 0.036), and IL-6 levels (p = 0.008). TAS levels decreased (p = 0.006), while enzymatic antioxidants, such as SOD increased (p = 0.031). Erythrocyte GSH remained low, with a non-significant postoperative decrease. Patients with higher K-L grades exhibited greater redox imbalance, with reduced preoperative GSH and elevated postoperative superoxide anion, TOS, and SOD levels. More severe cases also showed decreased postoperative erythrocyte, hemoglobin, and PTH levels, and increased TAS and AOPP levels. Factorial analysis highlighted clusters associated with oxidative stress, inflammation, and clinical performance. Conclusions: The results underscore the complex relationship between inflammation, oxidative stress, and recovery in sOA. These findings suggest the importance of targeted postoperative strategies to support redox homeostasis and modulate inflammation in sOA patients. Full article

This study investigated the sorption properties of the biomass of larch (LaC), pine (PiC) and spruce cones (SpC) in relation to the anionic dye Reactive Black 5 (RB5) and cationic Basic Red 46 (BR46). The scope of the study included the properties of the sorbents (FTIR, SSA, fiber content, elemental analysis C, N, H, pH_PZC), the effect of pH on the sorption efficiency of the dyes, the sorption kinetics (pseudo-first-order model, second-order model, intraparticle diffusion model) and the maximum sorption capacity of the sorbents (Langmuir 1 and 2 models, Freundlich). The sorption efficiency of RB5 on the sorbents tested was highest at pH 2 and BR46 at pH 6. The pH_PZC values determined for LaC, PiC and SpC were 6.86, 7.02 and 7.19, respectively. The sorption equilibrium time depended mainly on the initial dye concentration and ranged from 150 to 180 min for RB5 and from 120 to 210 min for BR46. The sorption capacities (Q_max) of LaC, PiC and SpC for RB5 were 1.05 mg/g, 1.12 mg/g and 1.61 mg/g, respectively, and for BR46 were 70.53 mg/g, 76.60 mg/g and 96.44 mg/g, respectively. The most efficient sorbent for both dyes was SpC, which was partly related to the high lignin content of the material. Full article

Modeling ion transport through membrane channels is crucial for understanding cellular processes, and Poisson–Nernst–Planck (PNP) equations provide a fundamental continuum framework for such ionic fluxes. We investigate a quasi-one-dimensional steady-state PNP system for two oppositely charged ion species, focusing on how large permanent charges within the channel and realistic boundary conditions impact ion transport. In contrast to classical models that impose ideal electroneutrality at the channel ends (a simplification that eliminates boundary layers near the membrane interfaces), we adopt relaxed neutral boundary conditions that allow small charge imbalances at the boundaries. Using asymptotic analysis treating the large permanent charge as a singular perturbation, we derive explicit first-order expansions for each ionic flux, incorporating boundary layer parameters $(\sigma ,\rho )$ to quantify slight deviations from electroneutrality. This analysis enables a qualitative characterization of individual cation and anion flux behaviors. Notably, we identify two critical transmembrane potentials, $V_{1c}$ and $V_{2c}$, at which the cation and anion fluxes, respectively, vanish, signifying flux-reversal thresholds that delineate distinct monotonic regimes in the flux-voltage response; these critical values depend on the permanent charge magnitude and the boundary layer parameters. We further show that both ionic fluxes exhibit saturation: as the applied voltage becomes extreme, each flux approaches a finite limiting value, with the saturation level modulated by the degree of boundary charge imbalance. Moreover, allowing even small boundary charge deviations reveals non-intuitive discrepancies in flux behavior relative to the ideal electroneutral case. For example, in certain parameter regimes, a large permanent charge that enhances an ionic current under strict electroneutral conditions will instead suppress that current under relaxed-neutral conditions (and vice versa). This new analytical framework exposes subtle yet essential nonlinear dynamics that classical electroneutral assumptions would otherwise obscure. It provides deeper insight into the interplay between large fixed charges and boundary-layer effects, emphasizing the importance of incorporating such realistic boundary conditions to ensure accurate modeling of ion transport through membrane channels. Numerical simulations are performed to provide more intuitive illustrations of our analytical results. Full article

In coastal countries facing a shortage of drinking water, seawater desalination is essential for the production of potable water. During desalination, a large volume of waste stream, known as brine, is generated. This stream contains high concentrations of salts, particularly those of economic importance to the European Union, such as magnesium and calcium. By further processing this stream, these materials can be recovered. One method studied for separating magnesium from wastewater is membrane crystallization (MCr). The MCr process developed in this work utilizes ion-exchange membranes that separate the model brine solution from a precipitating agent, which is a solution of sodium hydroxide. During the process, the membrane allows the transport of anions between the two solutions, enabling the reaction between OH⁻ anions and Mg²⁺ cations, which leads to the formation of a magnesium hydroxide precipitate. The formed precipitate can then be filtered out of the brine solution, which now has decreased salinity due to crystallization facilitated by the ion-exchange membrane. However, precipitation occurs near the membrane surface, resulting in the deposition of magnesium hydroxide onto the outer surface of the membrane. The aim of this study is to investigate methods for effectively removing magnesium hydroxide from the membrane surface, with a primary focus on maximizing the yield of magnesium hydroxide crystals in suspension. Crystal removal was induced by circulation of hydrochloric acid, followed by circulation of demineralized water through the membrane module after crystallization. In this study, a membrane module made of hollow-fiber anion-exchange membranes was employed. The production cost of these membranes is approximately 50% lower per square meter compared to flat-sheet membranes commonly used in electrodialysis, demonstrating strong potential for commercial application. More than 85% magnesium conversion was achieved during the process, yet the majority of the crystals remained attached to the membrane. Circulation of hydrochloric acid and demineralized water after the crystallization process caused detachment of the crystals into suspension, nearly doubling their yield. Full article

Understanding the molecular structure and water transport behavior in anion-exchange membranes (AEMs) is essential for advancing efficient and cost-effective alkaline fuel cells. In this study, large-scale all-atom molecular dynamics simulations of QPAF-4, a promising AEM material, were performed at multiple water uptakes (λ = 2, 3, 6, and 13). The simulated systems comprised approximately 1.4 to 2.1 million atoms and spanned approximately 26 nm, thus enabling direct comparison with both wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) experiments. The simulations successfully reproduced experimentally observed structure factors, accurately capturing microphase-separated morphologies at the mesoscale ($~$8 nm). Decomposition of the SAXS profile into atom pairs suggests that increasing water uptake may facilitate the aggregation of fluorinated alkyl chains. Furthermore, the calculated pair distribution functions showed excellent agreement with WAXS data, suggesting that the atomistic details were accurately reproduced. The water dynamics exhibited strong dependence on hydration level: At low water uptake, mean squared displacement showed persistent subdiffusive behavior even at long timescales ($~$200 ns), whereas almost normal diffusion was observed when water uptake was high. These results suggest that water mobility may be significantly influenced by nanoconfinement and strong interactions exerted by polymer chains and counterions under dry conditions. These findings provide a basis for the rational design and optimization of high-performance membrane materials. Full article

Municipal wastewater treatment relies primarily on biological methods, yet effective disposal of residual sludge remains a major challenge. Converting sludge into biochar via oxygen-limited pyrolysis presents a novel approach for waste resource recovery. This study prepared sludge-based biochar (SBC) through one-step pyrolysis of sewage sludge and applied it to activate peroxymonosulfate (PMS) for degrading diverse contaminants. Characterization (SEM, XPS, FTIR) revealed abundant pore structures and diverse surface functional groups on SBC. Using Acid Orange 7 (AO7) as the target pollutant, SBC effectively degraded AO7 across pH 3.0–9.0 and catalyst dosages (0.2–2.0 g·L⁻¹), achieving a maximum observed rate constant (k_obs) of 0.3108 min^–1. Salinity and common anions showed negligible inhibition on AO7 degradation. SBC maintained 95% degradation efficiency after four reuse cycles and effectively degraded sulfamethoxazole, sulfamethazine, and rhodamine B besides AO7. Mechanistic studies (chemical quenching and ESR) identified singlet oxygen (¹O₂) and superoxide radicals (O₂^•− ) as the dominant reactive oxygen species for AO7 degradation. XPS indicated a 39% reduction in surface carbonyl group content after cycling, contributing to activity decline. LC-MS identified five intermediates, suggesting a potential degradation pathway driven by SBC/PMS system. ECOSAR model predictions indicated significantly reduced biotoxicity of the degradation products compared to AO7. This work provides a strategy for preparing sludge-derived catalysts for PMS activation and pollutant degradation, enabling effective solid waste resource utilization. Full article

The advancement of efficient energy conversion and storage technologies is fundamentally linked to the development of electrochemical systems, including fuel cells, batteries, and electrolyzers, whose performance depends on key electrocatalytic reactions: hydrogen evolution (HER), oxygen evolution (OER), oxygen reduction (ORR), carbon dioxide reduction (CO₂RR), and nitrogen reduction (NRR). Beyond catalyst design, the electrolyte microenvironment significantly influences these reactions by modulating charge transfer, intermediate stabilization, and mass transport, making electrolyte engineering a powerful tool for enhancing performance. This review provides a comprehensive analysis of how fundamental electrolyte properties, including pH, ionic strength, ion identity, and solvent structure, affect the mechanisms and kinetics of these five reactions. We examine in detail how the electrolyte composition and individual ion contributions impact reaction pathways, catalytic activity, and product selectivity. For HER and OER, we discuss the interplay between acidic and alkaline environments, the effects of specific ions, interfacial electric fields, and catalyst stability. In ORR, we highlight pH-dependent activity, selectivity, and the roles of cations and anions in steering 2e⁻ versus 4e⁻ pathways. The CO₂RR and NRR sections explore how the electrolyte composition, local pH, buffering capacity, and proton sources influence activity and the product distribution. We also address challenges in electrolyte optimization, such as managing competing reactions and maximizing Faradaic efficiency. By comparing the electrolyte’s effects across these reactions, this review identifies general trends and design guidelines for enhancing electrocatalytic performance and outlines key open questions and future research directions relevant to practical energy technologies. Full article

Cadmium (Cd) is a major co-occurring, highly toxic heavy metal in uranium (U) tailings that poses synergistic risks to ecological and human health. This study aimed to investigate the effects of Cd on U accumulation and phytotoxicity in plants using radish (Raphanus sativus L.) as a model organism under hydroponic conditions. Treatments included U alone (25 μM and 50 μM), low-concentration Cd alone (10 μM), and U + Cd co-treatments (U25 + Cd and U50 + Cd). Results revealed that exposure exerted minimal phytotoxicity, whereas U treatment induced severe root toxicity, characterized by cell death and an 11.9–63.8% reduction in root biomass compared to the control. Notably, U + Cd co-treatment exacerbated root cell death and biomass loss relative to U alone. Physiologically, elevated U concentrations significantly increased superoxide anion radical (O₂⁻) production rate, hydrogen peroxide (H₂O₂) content, and malondialdehyde (MDA)—a marker of oxidative damage—inducing cellular oxidative stress. Under U + Cd co-treatment, O₂⁻ production, H₂O₂ content, and MDA levels in radish roots were all significantly higher than under U alone. Concurrently, activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], and peroxidase [POD]) were lower in U + Cd-treated roots than in U-treated roots, further exacerbating oxidative damage. Regarding heavy metal accumulation, the content of U in radish under U + Cd treatment was significantly higher than that in the U treatment group. However, no significant differences were observed in the expression of uranium (U)-related transport genes (MCA1, MCA3, and ANN1) between the single U treatment and the U-Cd co-treatment. Notably, the inhibitory effect of NRAMP3—a gene associated with Cd transport—was weakened under the coexistence of U, indicating that U exacerbates toxicity by promoting Cd transport. This study shows that Cd appears to enhance the accumulation of U in radish roots and exacerbate the phytotoxicity of U. Full article

Surfactants are used in various washing applications with potential negative environmental and health impacts. The ion-pair 1,3-dioctadecyl-1H-1,2,3-triazol-3-ium-tetraphenylborate (DODTA–TPB) was used to fabricate the potentiometric sensor for the quantification of anionic surfactants. The computational analysis of the DODTA⁺–TPB⁻ adduct reveals a dynamic, thermodynamically favorable interaction driven primarily by hydrophobic C–H∙∙∙π contacts and the flexibility of the C-18 chains, rather than electrostatic or π–π stacking forces. These findings, supported by the MM-PBSA, RDF, and structural analyses, align with broader trends in molecular recognition and provide a foundation for designing advanced ion-pair-based sensors. The sensor showed advanced analytical properties to anionic surfactants with low interfering effects of selected anions. The response of the SDS was investigated in the range from 8.1 × 10⁻⁸ M to 1.0 × 10⁻² M, with a slope of −59.2 mV and a limit of detection (LOD) of 3.1 × 10⁻⁷ M; and DBS was in the range of 8.1 × 10⁻⁸ M to 2.5 × 10⁻³ M with a slope of −57.5 mV and an LOD of 5.9 × 10⁻⁷ M. The sensor was tested on potential interfering ions. Potentiometric titrations of technical-grade anionic surfactants had high recovery rates from 100.2 to 100.4%. The recovery test for spiked samples of surface waters was from 94.2 to 96.5%. The sensor was tested on commercial samples containing anionic surfactants, and the results were compared and showed a good agreement with the two-phase titration method. Full article

Mitochondria-associated membranes (MAMs) are essential for cellular homeostasis. MAMs are specialized contact sites located between the endoplasmic reticulum (ER) and mitochondria and control apoptotic pathways, lipid metabolism, autophagy initiation, and calcium signaling, processes critical to the survival and function of neurons. Although this area of membrane biology remains understudied, increasing evidence links MAM dysfunction to the etiology of major neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS). MAMs consist of a network of protein complexes that mediate molecular exchange and ER–mitochondria tethering. MAMs regulate lipid flow in the brain, including phosphatidylserine and cholesterol; disruption of this process causes membrane instability and impaired synaptic function. Inositol 1,4,5-trisphosphate receptor—voltage-dependent anion channel 1 (IP3R-VDAC1) interactions at MAMs maintain calcium homeostasis, which is required for mitochondria to produce ATP; dysregulation promotes oxidative stress and neuronal death. An effective therapeutic approach for altering neurodegenerative processes is to restore the functional integrity of MAMs. Improving cell-to-cell interactions and modulating MAM-associated proteins may contribute to the restoration of calcium homeostasis and lipid metabolism, both of which are key for neuronal protection. MAMs significantly contribute to the progression of neurodegenerative diseases, making them promising targets for future therapeutic research. This review emphasizes the increasing importance of MAMs in the study of neurodegeneration and their potential as novel targets for membrane-based therapeutic interventions. Full article

Dipeptide carnosine has gained attention for its antioxidant and anti-inflammatory effects demonstrated in preclinical studies, but evidence from human trials remains limited. This study investigated whether dietary carnosine delivered through enriched chicken meat can modulate redox status in competitive athletes. This randomized controlled trial involved 35 male competitive athletes who were assigned to either a control group (N = 16; CTRL) consuming regular chicken meat (410 mg/day) or a carnosine group (N = 19; CAR) receiving carnosine-enriched chicken meat (590 mg/day) for 21 days. Blood sample collection, cells isolation and anthropometric measurements were performed before and after the intervention to assess antioxidant enzyme activity, intracellular reactive oxygen species production, 8-iso Prostaglandin F2α (8-iso PGF 2α) concentration, and cell adhesion molecules serum concentrations. Results were expressed as mean ± standard deviation (SD). Group comparisons were conducted using parametric and non-parametric tests, ANCOVA was applied to assess post-intervention differences adjusted for baseline values, while a two-way ANOVA was performed to determine the significance of interactions between time and treatment for each parameter, significance set at p < 0.05. CAR group showed a significant reduction in serum 8-iso PGF 2α and increased SOD activity compared to baseline and the CTRL group. Intracellular hydrogen peroxide and peroxynitrite production increased, while superoxide anion production decreased in the CAR group. Carnosine-enriched chicken meat consumption significantly reduced lipid peroxidation, increased serum enzyme activity, and decreased superoxide anion production in competitive athletes. While further research is needed to elucidate the mechanisms and key factors behind it, the observed changes indicate that carnosine-enriched chicken meat consumption affects SOD activity consequently producing an antioxidative effect. Full article

Water-soluble polymers are often used as additives to adjust the foam properties of surfactant. In this study, the effects of water-soluble polymer poly(ethylene oxide) (PEO) on foam properties of two anionic surfactants, i.e., ammonium lauryl ether sulfate (ALES) and sodium dodecyl sulfate (SDS), were investigated by experimental and molecular dynamics simulation methods. Experimental results show that the addition of PEO can reduce the foaming ability of the two surfactants, but the inhibitory effect of PEO on the foaming ability is weakened at high surfactant concentration. Compared with ALES, PEO has a more significant inhibitory effect on the foaming ability of SDS. With the increase in PEO concentration, the half-life time of foam drainage in surfactant/water-soluble polymer composite systems gradually increases. The synergistic effect between PEO and ALES is stronger than that between PEO and SDS, resulting in a longer half-life time of foam drainage in ALES/PEO composite system. Molecular dynamics simulation results indicate that the addition of PEO can decline the air–water interface thickness of bubble films and the tail tilt angle of surfactant molecules at the air–water interface. The reduction in tail tilt angle means that the surfactant molecules are more vertical to the air–water interface and the hydrophobic interaction between adjacent tail chains of surfactants is weakened, which is unfavorable to the formation of bubble films, thus decreasing the foaming ability of surfactants. Because the ALES/PEO system has larger air–water interface thickness and surfactant tail tilt angle than the SDS/PEO system, the inhibitory effect of PEO on the foaming ability of ALES is weaker than that of SDS. Adding PEO can lower the peak position of the first hydration layer of surfactant head groups, increase the number of hydrogen bonds, and reduce the diffusion coefficient of water molecules, so that the surfactant/water-soluble polymer system has longer half-life time of foam drainage than the pure surfactant system. Due to the synergistic effect between ALES and PEO, the ALES/PEO system has a higher peak value of the first hydration layer of surfactant head groups, more hydrogen bonds, and lower diffusion coefficient of water molecules than the SDS/PEO system. Therefore, the half-life time of foam drainage in the ALES/PEO system is longer than that in the SDS/PEO system. Full article

Boric acid/β-CD-based polymers (BA-CD) possess hierarchical porous structures and efficient functional groups for further molecular recognition, which are used for the adsorption of a series of cationic and anionic organic dyes. The effects of pH, contact time, initial concentration of solution, and temperature on the adsorption performance were experimentally investigated in detail. Surprisingly, the adsorption capacities of BA-CD towards RB exhibited a higher value of 733.2 mg g⁻¹ among a series of cationic and anionic dyes. The adsorption kinetics further indicated that the adsorption of dyes by BA-CD belonged to a quasi-second-order kinetic model, while the adsorption isotherms demonstrated the adsorption process as the Langmuir isotherm model. The characterization of the adsorption process was performed in the presence of monomolecular layer chemisorption. In addition, the reusability test showed that BA-CD had a high reusability rate of 90% in MG after five cycles, indicating its future potential for the treatment of dye wastewater. Full article

Ultraviolet B (UV-B) radiation is a key environmental factor that limits plant growth and development. High UV-B intensity is a typical environmental feature in Turpan-Hami (Tuha) Basin in Xinjiang, China. In this study, the altitude-dependent UV-B adaptation strategies of plants in Tuha Basin were analyzed. Chlorophyll (Chl) and flavonoid (Fla) play an important role in absorbing UV-B radiation, scavenging free radicals, and maintaining photosynthetic performance under UV-B stress. Principal component analysis indicated that the total chlorophyll (Chl t), Chl a, Chl b, and Fla contents and the Chl a/Chl b ratio are important indicators for evaluating plant tolerance to UV-B. Noticeably, with increased altitudes, the roles of Chl b, Chl a/Chl b, and Fla become markedly significant. The characteristics of stomata, epidermal hair, and wax layer are closely correlated with the UV-B amount that reaches leaves. Epidermal hair density and cuticle thickness in leaves decreased with increased altitudes, whereas hydrogen oxide (H₂O₂) was significantly accumulated, but superoxide anion (O₂⁻) remained unchanged. High altitude significantly increased the stomatal apparatus area, density and specific leaf area. Moreover, plants without epidermal hair had a larger stomatal apparatus area compared with plants with epidermal hair. However, the presence or absence of epidermal hair had no effect on cuticle thickness, H₂O₂ and O₂⁻ levels. The carbon (C), nitrogen (N), and hydrogen (H) contents were high in plant leaves at high altitude, but the sulfur (S) content and C/N ratio were low. Taken together, plants in Tuha Basin could cope with UV-B radiation by synergistically regulating epidermal structures and synthesis of secondary metabolites. Meanwhile, these plants could further allocate and reconstruct organic elements to optimize their resource distribution in adaptation to UV-B radiation with different altitudes. Full article

This study deciphers the anionic modulation mechanism of halide ions (F⁻/Cl⁻) in cobalt-based hydroxides for oxygen evolution reaction (OER). Phase-pure Co(OH)₂, Co(OH)F, and Co₂(OH)₃Cl were fabricated via substrate-independent hydrothermal synthesis to eliminate conductive support interference. Electrocatalytic evaluation on glassy carbon electrodes demonstrates fluoride’s superior regulatory capability over chloride. X-ray photoelectron spectroscopy (XPS) analyses revealed that F⁻ incorporation induces charge redistribution through Co → F electron transfer, optimizing the electronic configuration via ligand effects. F⁻ incorporation simultaneously guided the anisotropic growth of 1D nanorods and reduced surface energy, thereby enhancing the wettability of Co(OH)F. The engineered Co(OH)F catalyst delivers exceptional OER performance: 318 mV overpotential at 10 mA/cm² in 1 M KOH with 94% current retention over 20 h operation. This study provides a synthetic strategy for preparing pure-phase Co(OH)F and compares halide ions’ effects on enhancing OER activity through electronic structure modulation and morphological control of basic cobalt salts. Full article