Search Results (10,280)

Volcanic super-eruptions can perturb atmospheric composition and climate-relevant radiative properties in ways that are not captured by simple scaling from Pinatubo-like events. This study presents a reduced-order regime theory for the coupled evolution of stratospheric sulfur, sulfate aerosol burden, reactive halogens, ozone loss, stratospheric thermal adjustment, and aerosol residence time. The analysis is intended as an interpretive tool for organizing sulfur-rich volcanic scenarios, comparing literature-based benchmark classes, and designing chemistry–climate model experiments, rather than as an event-specific calibration or a substitute for three-dimensional models. Four control parameters structure the response: sulfur loading relative to microphysical saturation, effective halogen strength, ash-uptake efficiency, and dynamical lifetime sensitivity, with hemispheric asymmetry treated diagnostically. An external consistency check against published Pinatubo-like, idealized 10–40 teragrams of sulfur (Tg S), Toba-like, and Los Chocoyos-like responses is used to evaluate whether the reduced theory reproduces the expected rank ordering of aerosol saturation, forcing-efficiency decline, ozone-loss amplification, ash-driven sulfur suppression, and residence-time sensitivity. This comparison does not assign pointwise error margins against three-dimensional model output; it evaluates regime membership, sign of response, rank ordering, and broad magnitude behavior. The main conclusion is that volcanic super-eruption impacts are governed by interacting regime transitions rather than by sulfur mass alone. Microphysical saturation can limit forcing efficiency, halogens can shift the system toward chemically amplified ozone depletion, ash uptake can reduce the effective sulfur burden during the early phase, and dynamical state can control persistence and hemispheric expression. By separating these mechanisms, the study provides a compact basis for interpreting large volcanic perturbations to atmospheric chemistry and for designing targeted model experiments on extreme eruption scenarios. Full article

Smilacis Glabrae Rhizoma is a traditional Chinese medicine commonly used for hyperuricemia. Engeletin, one of its major flavonoids, exhibits various pharmacological activities, but its in vivo uric acid-lowering activity and metabolic processes remain unclear. This study aims to elucidate the in vivo existence forms of engeletin and the pharmacological basis underlying its uric acid-lowering effects. The in vivo metabolites of engeletin were identified by using UHPLC-Q-TOF-MS. The xanthine oxidase inhibitory activity was investigated using in vitro enzymatic assays. The in vivo uric acid-lowering effect was evaluated in hyperuricemic mice. A total of 11, 34, 7, 6, and 5 compounds were detected in urine, feces, serum, liver, and kidney samples, respectively. After removing duplicates, 52 compounds were preliminarily identified as in vivo existence forms of engeletin. The main metabolic reaction types were glucuronidation, sulfation, and hydrolysis. Engeletin exhibited no xanthine oxidase inhibitory activity in vitro but possessed uric acid-lowering activity in vivo. Neoisoastilbin and naringenin were metabolites with both xanthine oxidase inhibitory activity and uric acid-lowering activity. The in vivo uric acid-lowering activity of engeletin may be attributable to its two metabolites rather than itself. This study elucidated the pharmacological basis of engeletin and laid the foundation for developing potential therapeutics for hyperuricemia. Full article

This study examined the chemical composition and quantitative source contributions of coarse (PM_10–2.5) and fine (PM_2.5) particles in ship-based PM₁₀ and PM_2.5 filter samples from 2020 to 2024 across the Yellow Sea. The observations were primarily conducted during the spring season, when the influence of continental air masses from East Asia is pronounced, and detailed analyses of water-soluble ions and elemental species were performed. In coarse particles, sea salt components (e.g., Na⁺ and Cl⁻) and soil-derived species (e.g., nss-Ca²⁺ and CO₃²⁻) were predominant, whereas fine particles were dominated by secondary inorganic species such as nss-SO₄²⁻, NO₃₋, and NH₄⁺. Source contributions were estimated using Dispersion Normalized Positive Matrix Factorization (DN-PMF), and eight common factors were identified, including sea salt, soil, secondary nitrate, secondary sulfate, oil combustion, biomass burning, marine biogenic emissions, and plant growth. Additionally, an industry factor was uniquely resolved in coarse particles, whereas a mobile source factor was identified in fine particles. In coarse particles, sea salt (30.9%) and soil (15.1%) were the major contributing sources, whereas fine particles were dominated by secondary nitrate (48.6%) and secondary sulfate (15.6%). Potential Source Contribution Function (PSCF) analysis indicated that the sea salt and oil combustion factors in coarse particles were associated with coastal regions of the Yellow Sea and the East China Sea, while the soil factor corresponded spatially with inland regions of northern China. In contrast, the secondary nitrate, secondary sulfate, and biomass burning factors in fine particles showed strong associations with inland regions of eastern China. Using size-resolved DN-PMF and five years of repeated observations over the same marine region, this study provides the first quantitative source apportionment analysis of interannual atmospheric composition variability and long-range transport affecting air quality over the Yellow Sea. Full article

The environmental impacts of treated acid mine drainage on receiving river systems remain insufficiently understood. This study investigated four typical closed coal mines in northern Sichuan Province, China, by analyzing heavy metals, sulfate, pH, UV-Vis spectroscopy, and dissolved organic matter (DOM) characteristics at 24 sampling sites along the receiving reaches. Parallel factor analysis (PARAFAC) and two-dimensional correlation spectroscopy (2D-COS) were employed to examine the longitudinal response sequence of DOM components. Results showed that pollutant concentrations generally increased immediately after the inflow of treated acid mine drainage and then progressively attenuated downstream, although the dominant pollution factors varied significantly among the reaches. DOM composition exhibited spatial heterogeneity, with protein-like components dominating three reaches and humic-like components prevailing in one reach. Based on the co-variation characteristics of DOM and heavy metals along the river course, four response patterns were identified: rapid-recovery, slow-recovery, disturbance–oscillation recovery, and delayed-recovery patterns. The 2D-COS analysis validated the rationality of these four patterns and revealed differences in the sensitivity of various DOM components to longitudinal disturbances. This study provides a scientific basis for the environmental impact assessment of mine water from remediated closed coal mines. Full article

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by recurrent intestinal inflammation and mucosal injury. This study evaluated the protective potential of red ginseng ethanolic extract (RGEE) using a dextran sulfate sodium (DSS)-induced colitis mouse model and an LPS-stimulated RAW 264.7 macrophage model. Preliminary LC-MS profiling was also performed to characterize the detectable chemical features of RGEE. In vivo, RGEE alleviated DSS-induced body weight loss, disease activity, colon shortening, spleen enlargement, and histopathological injury, with the histopathological score reduced by approximately 51.1%. RGEE also partially improved DSS-induced hematological alterations without causing obvious changes in major organ weights. In vitro, RGEE showed no obvious cytotoxicity up to 250 μg/mL and reduced LPS-induced NO, TNF-α, IL-6, and IL-1β production by approximately 60.0–67.1%. LC-MS analysis putatively annotated several saponin-related features, including notoginsenoside R1 and ginsenosides Rb1, Rb2, Rh1, Rh4, and Rh2. These findings suggest that RGEE has protective potential against DSS-induced colitis, which is associated with the suppression of inflammatory mediator production. Further studies are needed to clarify its active constituents and mechanisms of action. Full article

Chronic kidney disease (CKD) affects approximately 700 million people worldwide and is a major contributor to end-stage renal disease (ESRD), cardiovascular morbidity, and premature mortality. Although oxidative stress has long been considered central to CKD progression, conventional antioxidant strategies have not consistently improved clinical outcomes, suggesting that excess reactive oxygen species (ROS) alone cannot fully account for the underlying disease pathophysiology. Emerging evidence supports a broader paradigm of redox network failure, characterized by the disruption of coordinated signaling among ROS, nitric oxide (NO), and reactive sulfur species (RSS). Within this framework, hydrogen sulfide (H₂S), a major endogenous RSS, functions as a key regulator of renal redox homeostasis. CKD is consistently associated with systemic and renal H₂S deficiency, accompanied by downregulation of cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3-MST), as well as impaired transsulfuration and disrupted mitochondrial sulfide oxidation. Importantly, this deficiency cannot be explained solely by reduced renal function but instead reflects active suppression of H₂S biosynthesis. Uremic toxins, particularly indoxyl sulfate (IS), contribute to this process through activation of the aryl hydrocarbon receptor (AhR), which inhibits specificity protein 1 (Sp1)-dependent transcription of H₂S-producing enzymes. This IS–AhR–Sp1 axis provides a mechanistic link between toxin accumulation and disruption of the sulfur arm of the redox network, amplifying oxidative stress, endothelial dysfunction, mitochondrial impairment, ferroptotic vulnerability, and fibrotic remodeling. Beyond H₂S itself, downstream RSS, including persulfides, polysulfides, and thiosulfate, may represent the principal bioactive mediators of sulfur-dependent redox signaling, and their coordinated depletion in CKD may impair redox buffering capacity beyond what H₂S measurement alone reflects. This review integrates current evidence to propose a conceptual model in which CKD progression involves failure of coordinated redox signaling—characterized by feed-forward network collapse and threshold-dependent transition to a self-sustaining high-ROS state—with H₂S deficiency representing one mechanistically supported component of this broader network disruption. This framework highlights the therapeutic potential of targeting redox network restoration rather than isolated oxidative pathways in CKD. Full article

To efficiently degrade tetracycline (TC) antibiotic pollution, cobalt-based (Co-OMCs/F) and cobalt–copper bimetallic ((Co+Cu)-OMCs/F) monolithic mesoporous carbon catalysts were synthesized using resorcinol–formaldehyde resin as a carbon precursor, with hexamethylenetetramine (HMT) and formaldehyde (CH₂O) as crosslinking agents, followed by high-temperature carbonization under N₂. The materials were characterized by XRD, SEM-EDX, HRTEM, and EPR. Key factors-metal loading, PMS concentration, initial pH, and flow rate-were investigated for their effects on TC degradation. Degradation mechanisms and stability were assessed via radical quenching and continuous-flow cycling tests. Results show optimal performance at a cobalt loading of 0.6 g. Compared to CH₂O, HMT favors a three-dimensional interconnected mesoporous carbon framework with uniform metal distribution and high crystallinity. Under conditions of 25 mg/L TC, 0.33 mmol/L PMS, pH 7, and 2 mL/min flow rate, the (Co+Cu)-OMCs/F (HMT) catalyst achieved ~93% TC degradation over 9 h of continuous operation, and 95% after three reuse cycles, significantly outperforming the single-metal Cu-OMCs/F catalyst. Radical quenching and EPR identified superoxide radicals (·O₂⁻) as the dominant active species (~78% contribution), with sulfate radicals (SO₄^·−), hydroxyl radicals (·OH), and singlet oxygen (¹O₂) playing synergistic roles. The synergistic Co-Cu bimetallic effect, combined with the confinement effect of the mesoporous carbon support and HMT-induced uniform nucleation, endows the catalyst with high activity and long-term stability. This work provides a theoretical basis for designing efficient, reusable, monolithic mesoporous carbon-based PMS activation catalysts for advanced antibiotic wastewater treatment. Full article

Early-age strength development and carbon emissions represent specific operational constraints in underground cemented tailings backfill (CTB) operations. A pH and ionic pre-conditioning-assisted CO₂ mineralization process was evaluated for carbonate-rich cemented tailings backfill designed to improve early UCS while retaining measurable CO₂ uptake through systematic process control and optimization. Skarn-type tailings (CaO 16.74 wt%, total carbonates 34.7 wt%) were subjected to screening under nominal pH and ionic pre-conditioning treatments (4.0–11.5), CO₂ pressure (0–0.5 MPa), cement-to-tailings ratio (1:3–1:12), and slurry concentration (66–78%). Strength evolution (1–28 d), mineralization products were characterized using TGA as the primary CO₂-uptake method, with XRD used for semi-quantitative phase-trend assessment, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) with selected-area electron diffraction (SAED), X-ray computed tomography (CT), and nuclear magnetic resonance (NMR). Under optimal conditions (pH 8.5, 0.3 MPa CO₂ pressure, 48 h mineralization, 72–74% solids), mineralized specimens achieved 2-day uniaxial compressive strength equivalent to 1.47-times the 3-day control strength (p < 0.01), with peak net CO₂ sequestration of 37.1 g/kg. EBSD analysis of 347 grain boundaries and TEM-SAED examination of multiple foil sections supported the occurrence of syntaxial calcite overgrowth on primary carbonate debris as a major interfacial transition zone strengthening mechanism. Interconnected pore cluster volume decreased by 70.6%; Zn²⁺ and Pb²⁺ leaching decreased by 67.2% and 71.8%, respectively. A shrinking-core kinetics-Ryshkewitch model with pH-dependent correction functions predicted 3-day strength with acceptable accuracy for TW-A and TW-B, whereas TW-C showed a −27.3% deviation, identifying acidic and sulfate-rich wastewater as a boundary condition outside the reliable model domain. Field coring at −500 m depth provided pilot-scale evidence that a 23 mm mineralized shell was consistent with localized reduction of shallow exposed-face instability risk during the early free-standing period. Overall, the pH and ionic pre-conditioning-assisted CO₂ mineralization process is proposed as a laboratory-supported and field-informed screening framework for simultaneous early-strength enhancement and partial carbon sequestration in carbonate-rich cemented tailings systems. The resulting models and parameter guidance should be interpreted as preliminary design tools requiring further factorial optimization and long-term field validation before full site-specific deployment. Full article

Fat deposition in laying hens involves lipid synthesis, transport, storage, and allocation across multiple tissues, yet the metabolic links between abdominal fat (AF) and egg yolk (EY) lipid deposition remain unclear. Here, we integrated whole-genome resequencing data with untargeted metabolomic profiles from the liver, duodenum, ileum, cecum, and serum of 248 purebred Rhode Island Red hens at 100 weeks of age. We estimated metabolite-explained variance (me²) for 22 fat deposition-related traits, evaluated metabolite heritability, and combined Spearman correlation analysis with bidirectional generalized summary-data-based Mendelian randomization (GSMR) to identify shared metabolites and pathways associated with AF and EY traits. The me² showed clear tissue specificity, with the liver, serum, and duodenum showing significant explanatory signals for 77.3% (17/22), 72.7% (16/22), and 68.2% (15/22) of fat-related traits. Liver-, AF-, and body weight-related traits showed stronger metabolomic explanatory signals, with significant proportions of 71.4–100.0%, 28.6–100.0%, and 100.0% across tissues, respectively, whereas EY-related traits showed more restricted and tissue-specific associations (0–33.3%). Correlation analysis identified liver-enriched AF–EY shared metabolites (e.g., NADPH, cholesteryl sulfate, N6,N6,N6-trimethyllysine), most of which showed opposite association patterns between AF- and EY-related traits. Bidirectional GSMR prioritized 20 candidate metabolites with opposite putative effects on AF and EY traits, including CDP-choline, phosphorylcholine, and allantoin. Pathway integration highlighted fructose/mannose metabolism, glycerophospholipid metabolism, ABC transporters, folate/one-carbon metabolism, amino acid metabolism, and energy metabolism as core components of the AF–EY shared network. These findings reveal tissue-specific and shared metabolic bases of fat deposition and identify candidate metabolic signatures associated with lipid partitioning between abdominal fat and egg yolk in laying hens. Full article

Type 2 diabetes mellitus (T2DM) is a major global health burden characterized by insulin resistance, progressive pancreatic β-cell dysfunction, and chronic metabolic dysregulation. Marine seaweeds have emerged as a valuable source of bioactive natural products, particularly polyphenols and polysaccharides, with promising potential for diabetes management. This review focuses on three major contributions: first, the structural diversity of seaweed-derived polyphenols and polysaccharides; second, their multi-target mechanisms of glucose regulation; and third, the structure–activity relationships governing their bioactivities. Current evidence shows that these compounds may help manage type 2 diabetes in several ways, including inhibition of α-amylase and α-glucosidase, attenuation of oxidative stress and chronic inflammation, enhancement of insulin secretion and insulin sensitivity, regulation of lipid metabolism, and modulation of gut microbiota. Key structural determinants such as degree of polymerization, hydroxyl group density, sulfation level, molecular weight, and chemical modifications are discussed in relation to their functional properties. By linking chemical structure with biological function, these findings highlight marine seaweeds as a rich reservoir of multi-target therapeutic candidates for T2DM management and provide a scientific basis for their development as functional food ingredients or lead compounds for novel diabetes management drugs. Full article

Background: Postbiotics, including cell-free supernatants and their fractions, have emerged as a safe and effective alternative to live probiotics for managing intestinal inflammation. This study investigated the protective effects of low-molecular-weight fractions (<3 kDa) of the probiotic Limosilactobacillus fermentum CECT5716 (LMW-LF) in a murine model of experimental colitis. Methods: Male C57BL/6J mice were orally administered LMW-LF for 10 days prior to colitis induction with 3% dextran sodium sulfate (DSS) for 5 days. Colonic damage was assessed via the Disease Activity Index (DAI), histology, and immunofluorescence (Ocln and Ki67). Immune cell populations were analyzed by flow cytometry, while mucosal gene expression and gut microbiota composition were evaluated using RT-qPCR and 16S rRNA sequencing, respectively. Results: LMW-LF administration significantly attenuated clinical symptoms and macroscopic colonic damage. Treatment restored epithelial barrier integrity by upregulating tight junction proteins (Tjp1) and mucin genes (Muc1-3) while normalizing DSS-induced epithelial hyperproliferation. Immunologically, LMW-LF reduced pro-inflammatory monocyte infiltration; downregulated Il6, Tnfa, and Ifng; and promoted an immunoregulatory phenotype by enhancing Ampk expression and partially restoring regulatory T cell (Treg) populations. Furthermore, LMW-LF reshaped the gut microbiota by increasing alpha diversity and promoting the enrichment of beneficial taxa, specifically Akkermansia muciniphila, which correlated with improved mucus layer preservation. Conclusions: LMW-LF is an active fraction acting across the host–microbiota axis. By integrating epithelial protection, immunomodulation, and microbial reshaping, it represents a promising dietary strategy for the management of Inflammatory Bowel Diseases. Full article

Sulfate attack is a major cause of deterioration in tunnel lining concrete under aggressive underground conditions. This study investigates the sulfate resistance of fiber-reinforced ferroaluminate cement concrete incorporating steel slag powder through combined experimental and numerical approaches. Specimens with different fiber contents (0, 0.2%, and 0.4%) were subjected to dry–wet cycles in a 5% sodium sulfate solution. The results show that fiber incorporation significantly enhances sulfate resistance, with the optimal performance achieved at 0.2% fiber content. Compared with ordinary Portland cement concrete, ferroaluminate cement-based concrete exhibits improved durability, including lower mass variation, reduced strength degradation, and more stable dynamic elastic modulus. Microstructural analyses indicate that hydration products refine the pore structure, while fibers effectively inhibit crack propagation and expansion damage. Numerical simulation of tunnel lining structures further demonstrates that the optimized material reduces stress concentration, displacement, and crack development. Overall, the proposed material shows superior performance and promising application potential for tunnel linings in sulfate-rich environments. Full article

The successful realization of a circular economy in the cement industry, coupled with a substantial reduction in carbon emissions, relies on the development of sustainable alternative binder systems. This study investigated the physicomechanical performance and sulfate resistance of composites produced by alkali activation of natural perlite and blast furnace slag. The aim of the research was to improve mechanical properties under low- and medium-alkalinity conditions (5–10 M NaOH). The samples were cured at an ambient temperature of 20 °C and then treated with heat at 60 °C. These samples were then mechanically processed and subjected to five soak–dry cycles in 5% and 10% Na₂SO₄ solutions. The results showed that heat treatment resulted in the formation of a dense C-A-S-H gel, increasing compressive strength approximately eightfold, from 11.64 MPa to 92 MPa. However, perlite’s porous and brittle structure limits its flexural strength to 0.27 MPa; this value is insufficient for structural applications. Under severe sulfate attack (10% Na₂SO₄), samples cured at ambient temperature showed a 12% mass increase in the first cycle due to solution infiltration into capillary voids. As a consequence of extensive ettringite and gypsum formation, the specimens experienced severe deterioration, resulting in a complete loss of mechanical integrity and a residual compressive strength of 0 MPa. In contrast, heat-treated samples showed limited ion diffusion due to a denser matrix and an improved aggregate interface transition zone, resulting in a 2.6% mass increase and a residual compressive strength of 5.17 MPa. Consequently, the obtained findings indicate that thermally treated alkali-activated slag–perlite composites exhibit high resistance against sodium sulfate attack and may have potential for use in specific industrial environments with high sulfate concentrations. However, the performance of these materials under more complex aggressive conditions, such as mining environments involving magnesium sulfate exposure and acidic drainage waters, should be further validated through future studies. Full article

Microbially induced corrosion is a common problem in the petroleum industry. In this study, weight loss and surface analysis of grade 20 carbon steel corrosion witness samples were used to evaluate biocorrosion in produced fluids from different wells (Romashkino oilfield, Republic of Tatarstan, Russia). The structure of the resulting microbial communities in the systems with high corrosion indicators was elucidated. The addition of acetate/lactate, yeast extract, and sulfate was found to promote the growth of individual microorganisms in the designed systems and to increase the corrosion rate in several samples (to an average of 0.12 mm year⁻¹). The results of 16S rRNA gene sequence analysis showed that water from different wells from the Romashkino oilfield had distinct microbial compositions. The main genera in the analyzed waters were Oleidesulfovibrio, Halanaerobium, Proteiniphilum, Acetobacterium, Fusibacter, and Methanocrinis, but their relative abundances depended on the water itself and the type of stimulation. Acetogenic bacteria of the genera Fusibacter, Proteiniphilum, Acetobacterium, and acetoclastic methanogenic archaea Methanocrinis became dominant in the microbial community structure in the acetate-enriched systems in water from one of the studied wells. Electron donors, generated by various bacteria and artificially introduced ones, facilitated active dissimilatory sulfate reduction by Oleidesulfovibrio, Desulfotignum, Desulfocurvus, and Pseudodesulfovibrio in water from another production well. The obtained results are important for identifying the causes of premature failures of oilfield equipment, particularly in areas where microbial enhanced oil recovery is used. Full article

Lameness in cattle is generally described as a condition characterized by an abnormal walking or posture which is often managed with copper sulfate (CuSO₄) hoofbaths, e.g., in case of digital dermatitis (DD). This review evaluates in vivo trials from the last 15 years (January 2010–March 2026) and the efficacy of CuSO₄ hoofbaths, their environmental impact, and the availability and performance of alternative products and agents (e.g., nanomaterials), with the aim of identifying sustainable management strategies for dairy farms and One Health goals. The selection criteria focused on peer-reviewed references and technical reports published in English. Hoofbath wastes can introduce high copper (Cu) loads into manure (500–2000 mg/L), leading to soil accumulation, impaired non-pathogenic microbial populations, and potential co-selection for pathogen resistance. Therefore, CuSO₄ can be effective but poses environmental risks due to Cu accumulation in soil and water, with mean concentrations reaching 5.7 ± 6.6 ppm Cu in areas where hoofbath effluent is discharged. Cu-free alternatives (e.g., quaternary ammonium compounds, organic acids) show comparable efficacy in some studies, but independent data on their environmental degradation and ecotoxicity are lacking. Although CuSO₄ hoofbaths pose environmental risks, they remain the most effective solution in improving hoof health. Controlled in vivo trials revealed that weekly 5% CuSO₄ hoofbaths can reduce the occurrence of lameness caused by hoof problems including DD by over 50%. Full article