Search Results (8,402)

Sodium sulfate-activated slag cement is considered a highly promising low-carbon cementitious material; however, its application is limited by low early-age activation efficiency and slow strength development. This study aims to systematically elucidate the coupled regulatory mechanism of alkalinity (2% and 4% Na₂O equivalent) and sodium sulfate dosage on the performance of alkali-activated slag (AAS). Under standard curing conditions (20 ± 2 °C, relative humidity ≥ 95%), the macroscopic properties of the samples (workability, setting time, and compressive strength) and the evolution of their microstructure (analyzed by XRD, FTIR, and SEM-EDS) were evaluated. The results indicate that the effect of sodium sulfate on alkali-activated slag (AAS) strongly depends on the alkalinity. Under low-alkalinity conditions (2% Na₂O), sodium sulfate exhibits a synergistic activation effect by increasing the ionic concentration, promoting slag depolymerization and the nucleation of ettringite (AFt). Specifically, compared with the control, incorporating 6 wt% sodium sulfate (N2S6 mix) increased compressive strength by approximately 82% at 3 days and 21% at 28 days. In contrast, under high-alkalinity conditions (4% Na₂O), excessive sodium sulfate (≥2 wt%) shows an inhibitory effect. This is likely because an excess of sodium sulfate interferes with the normal polymerization pathways of the aluminosilicate network, suppressing the formation of the primary C-(A)-S-H gel and thus significantly reducing later-age strength. Microstructural analysis revealed that the hydration products in the composite-activated system mainly consist of C-(A)-S-H gel, ettringite (AFt), monosulfate (AFm), and hydrotalcite. This study investigates the observed kinetic trends of anion-competitive hydration under different alkalinity conditions, providing a theoretical basis for the mix design of low-carbon alkali-activated materials and the valorization of coal chemical industrial salts. Full article

Global climate change and air pollution jointly threaten respiratory health. Asthma, a prevalent chronic inflammatory airway disease, is exacerbated by both traditional air pollutants such as particulate matter (PM_2.5), ozone (O₃), nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and emerging contaminants like microplastics (MPs) and per- and polyfluoroalkyl substances (PFAS), with effects amplified under extreme temperature conditions. In reality, individuals face complex combined exposures, yet the synergistic effects of these factors on asthma pathogenesis remain poorly understood. This narrative review synthesizes epidemiological and toxicological evidence. It aims to elucidate both the individual and the notably synergistic effects of these factors on asthma pathogenesis. The central mechanistic pathway is initiated by oxidative stress, which activates key inflammatory signaling pathways, thereby driving immune imbalance and airway inflammation. Our review underscores that the combined exposure to traditional pollutants, emerging pollutants, and extreme temperatures may pose a greater threat than individual factors. These findings underscore the critical need for an integrated perspective in asthma research and public health policy. Moving beyond single-pollutant approaches, we advocate for combinatorial risk assessment and synergistic intervention strategies to effectively mitigate the growing burden of asthma in a changing climate. Full article

Cadmium (Cd) and lead (Pb) co-contamination in construction and demolition waste landfill soils presents a significant challenge to ecosystem health, necessitating effective remediation strategies. This study investigated a synergistic approach combining a composite amendment (compost, superphosphate, desulfurized gypsum) with seven plant species to elucidate the interactions driving metal immobilization and phytoextraction. The amendment significantly altered soil properties: it reduced total Cd while increasing its bioavailability, and enhanced soil fertility (e.g., elevated organic matter and total nitrogen). Plant responses varied: Solanum americanum Mill. and Tagetes patula L. exhibited high Cd phytoextraction capacity, whereas Lolium perenne L. sequestered Cd/Pb primarily in roots. The bacterial community shifted from an oligotrophic, stress-tolerant state (e.g., Sphingomonas-dominated) in contaminated soil to a copiotrophic, functionally active state (e.g., Streptomyces-enriched) in amended soil. Community structure was strongly correlated with available Cd, pH, and nutrient levels. Key microbial biomarkers were specifically enriched in different plant rhizospheres. In contrast, the fungal community exhibited minimal responsiveness. These findings demonstrate that remediation efficiency is governed by an integrated “amendment–plant–microbe” framework: amendments regulate metal bioavailability, plants execute extraction or stabilization, and the restructured microbiome supports nutrient cycling and plant health. This integrated remediation strategy directly supports the Sustainable Development Goals of the 2030 Agenda, especially on environmentally sound management of chemicals and wastes and land degradation neutrality. This mechanistic understanding underscores the necessity of combined biological and chemical strategies for sustainable remediation of co-contaminated soils, ultimately enabling ecological reclamation and safe recycling of such urban marginal lands into productive uses. Full article

Oxidative stress is a key contributor to aging and chronic diseases, highlighting the need for safe and effective natural antioxidants. Monascus yellow pigments (MYPs) and ginsenoside Rg3 exhibit antioxidant activity, but their applications are restricted by low solubility and limited natural abundance. In this research, a bidirectional liquid fermentation system of Monascus ruber using ginseng decoction was established for the simultaneous production of water-soluble MYPs (WSMYPs) and ginsenoside Rg3. Process conditions were optimized to enhance the yields and the antioxidant activity of the system. Antioxidant assays and H₂O₂-induced RAW264.7 cell models confirmed that WSMYPs were strongly correlated with antioxidant capacity, with ABTS and DPPH scavenging activities showing 2.28-fold and 3.33-fold increases, respectively, compared to the control. Their combination with Rg3 exerted synergistic protective effects by enhancing the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT). Network pharmacology and molecular docking further revealed that Monapurone C, a representative WSMYP, and Rg3 act through a multi-target, multi-pathway antioxidant network involving signaling pathways such as PI3K-Akt. This study demonstrates a cost-effective strategy for co-producing WSMYPs and Rg3, providing new insights into the value-added utilization of edible and medicinal resources. Full article

Colorectal cancer remains a global health challenge due to its high mortality and therapy resistance. While Wedelia trilobata (L.) (WT) exhibits pharmacological potential, its specific mechanisms against this cancer are not fully understood. We investigated the anticancer effects of W. trilobata leaf ethanol extract and its n-hexane and chloroform fractions on HT-29 cells. The WT extract significantly inhibited proliferation by inducing G1/S phase arrest and downregulating PCNA mRNA. It triggered substantial DNA damage (increased γ-H2AX) and suppressed the mitogen-activated protein kinase (ERK) pathway. Notably, the WT extract-induced autophagy-mediated cell death, marked by acidic vesicular organelle formation and increased LC3-II levels. Inhibition of autophagy with N-acetylcysteine and 3-methyladenine partially rescued cell viability, restored p-Akt levels, and reduced LC3-II, indicating that cell death is regulated via the ROS-mediated Akt/mTOR signaling axis. Additionally, autophagic flux was validated using chloroquine, which led to a synergistic accumulation of LC3-II. GC-MS analysis identified 48 and 52 compounds in the n-hexane and chloroform fractions, respectively, including metabolites with known antioxidant and antitumoral properties. These findings demonstrate that W. trilobata induces autophagic cell death through ROS-mediated Akt/mTOR inhibition, supporting its potential as a source of innovative colorectal cancer therapeutics. Full article

Bacterial infections pose a persistent global threat to public health, driving the demand for rapid, sensitive, and specific detection technologies applicable to disease diagnosis, food safety, and environmental monitoring. Conventional methods like plate culture and polymerase chain reaction are often hampered by lengthy procedures, dependence on complex instrumentation, and requirements for specialized personnel. The emergence of nanozymes and nanomaterials with enzyme-like catalytic activities has introduced a paradigm shift in biosensing, offering superior stability, cost-effectiveness, and tunable functionality compared to their natural counterparts. This review provides a comprehensive and systematic analysis of the latest advancements in nanozyme-mediated bacterial detection. It is structured around the primary signal transduction modalities: colorimetric, fluorescence, electrochemical, and surface-enhanced Raman scattering (SERS) analyses. For each approach, we outline the fundamental design principles, which commonly integrate a synergistic cascade of specific recognition, catalytic signal amplification, and signal readout, and present representative applications for detecting key pathogens like Staphylococcus aureus, Salmonella, and Listeria monocytogenes in complex samples. We evaluate and contrast the advantages, analytical performance, and appropriateness of these different platforms for various practical scenarios. Finally, we address current challenges, including achieving high specificity in complex matrices, precise modulation of nanozyme activity, and method standardization. Perspectives on future research directions aimed at developing next-generation, high-performance, and potentially portable bacterial detection systems are also provided. Full article

Ultra-high-performance concrete incorporating coarse aggregates (UHPC-CA) exhibits pronounced multi-scale heterogeneity and staged damage evolution. However, existing single-scale reinforcement strategies often fail to address the complete micro-to-macro fracture process, leaving a critical research gap in achieving full-stage crack control. To address this, this study introduces a novel cross-scale toughening strategy using hybrid steel fibers (SF) and calcium carbonate whiskers (CCW), and decouples the coupled influences of water-to-binder (W/B) ratio, coarse aggregate (CA), and multi-scale fibers via an orthogonal design. Mechanical properties, fiber dispersion, and pore structure are jointly characterized to establish structure–property relationships. An optimal composition (W/B = 0.32, CA = 18%, SF = 2%, CCW = 1%) is identified, achieving a balanced enhancement of strength and ductility. Results indicate that matrix densification is primarily controlled by W/B via pore refinement, while mechanical performance is governed by the interplay between fiber spatial uniformity and interfacial integrity; the roles of CA and CCW are clearly stress-state dependent. Furthermore, a novel cross-scale synergistic mechanism is revealed, in which micro-scale CCW regulates microcrack initiation and stabilizes the pre-peak response, whereas macro-scale SF dominates post-peak behavior through crack bridging and pull-out energy dissipation. This sequential activation enables a full-stage enhancement of tensile performance, shifting failure from brittle localization to pseudo-ductile multiple cracking. The findings provide a correlative framework for tailoring UHPC-CA through multi-scale hybrid reinforcement. Full article

Continuous discharges from diverse industrial activities have severely degraded the water quality of the Lerma River, turning it into a major environmental, social, and public health concern. Conventional wastewater treatment processes are often insufficient for eliminating persistent and refractory organic pollutants; therefore, the implementation of advanced oxidation processes (AOPs) is increasingly required to restore water quality. In this context, the present study systematically evaluated the individual and combined effects of ozonation and electrochemical oxidation using boron-doped diamond (BDD) electrodes for the treatment of contaminated river water. Ozonation alone achieved an 89% reduction in turbidity and a 19% decrease in total organic carbon (TOC), while electrochemical oxidation reduced turbidity by 82% and TOC by 57%. Remarkably, the simultaneous application of both treatments resulted in a 98% reduction in turbidity and an 80% decrease in TOC, clearly demonstrating a strong synergistic effect. Regarding true color at 436 nm, associated with yellow chromophore compounds, removal efficiencies of 98.9%, 94.7%, and 67.3% were obtained for the combined process, electrochemical oxidation, and ozonation, respectively. Phytotoxicity tests with Lactuca sativa seeds showed no statistically significant difference in toxicity in water treated with the O₃–EO System compared to raw water. These results highlight, for the first time under real river water conditions, the superior performance of the integrated O₃–EO system as an effective strategy for the intensified degradation and partial mineralization of persistent organic contaminants, thereby underscoring its strong potential for advanced remediation of heavily polluted surface waters. Full article

Background: Chronic low back pain (CLBP) is a leading cause of disability worldwide, with exercise endorsed as first-line treatment and non-steroidal anti-inflammatory drugs (NSAIDs) among the most used pharmacologic options. These interventions are frequently combined in clinical practice, yet their synergistic effects remain unclear. To evaluate whether NSAID use modifies the association between physical activity (PA) and CLBP using nationally representative data from NHANES 2009–2010. Methods: We analyzed 988 adults aged ≥20 years with complete data on chronic low back pain, physical activity, medication use, and modeled covariates. Results: Among participants not using NSAIDs, moderate recreational physical activity was associated with lower odds of CLBP (adjusted OR = 0.47, 95% CI 0.25–0.91; p = 0.029). Active transport showed a similar direction but was not statistically significant (OR = 0.38, 95% CI 0.13–1.12; p = 0.074). In interaction models, active transport x aspirin was associated with higher odds of CLBP (OR = 2.24, 95% CI 1.02–4.90; p = 0.044), and moderate recreational PA x any NSAID use was also associated with higher odds of CLBP (OR = 2.26, 95% CI 1.01–5.06; p = 0.047). Subgroup analyses were exploratory and heterogeneous, including a significant potential protective interaction (OR ≈ 0.19, 95% CI 0.06–0.69; p = 0.015). Conclusions: In a nationally representative sample, NSAID use appeared to modify the association between physical activity and chronic low back pain. These findings are exploratory and hypothesis-generating. Therefore, longitudinal studies are needed to clarify the temporal and causal relationships and the potential influence of NSAIDs. Full article

In the present work, eleven self-shielded flux-cored wires with nickel (Ni) contents ranging from 1.42 wt.% to 4.02 wt.% were designed for the semi-automatic welding of X80 pipeline steel. The effects of Ni on the microstructural evolution and mechanical properties of the weld metal were investigated. The results indicate that when the Ni content is below 2.06 wt.%, the microstructures of both the solidification zone and the inter-pass reheating zone are dominated by coarse granular bainite and martensite/austenite (M/A) constituents. As the Ni content increases from 2.06 wt.% to 3.73 wt.%, the microstructure transforms to fine lath bainite with M/A constituents characterized by low content, small size, and uniform distribution. When the Ni content reaches 3.73 wt.%, the microstructure becomes almost fully bainite. Furthermore, with increasing the Ni content, both the yield strength and tensile strength of the weld metal increase from ~600 MPa to ~700 MPa and from ~660 MPa to ~730 MPa, respectively. However, the impact energy at −20 °C of the weld metal initially increases and then decreases, reaching a peak of ~110 J with the lowest degree of dispersion at a Ni content of approximately 3.73 wt.%. When the Ni content exceeds 3.73 wt.%, the ductility decreases slightly. Further analyses indicate that the synergistic effects of Ni in refining the microstructure and reducing the activity coefficient and solubility of nitrogen (N) jointly contribute to the impact toughness of the weld metal. Full article

Mercury pollution from artisanal and small-scale gold mining remains one of the most persistent environmental threats due to the high toxicity, mobility, and bioaccumulation of Hg(II). In this work, Colombian banana pseudostem waste is valorized into a lignocellulosic carbocatalyst through pyrolysis at 500 °C followed by MnCO₃-derived MnOx functionalization, producing a sustainable material for Hg(II) remediation. The transformation of the biomass leads from a fibrous structure (~25 µm) to a pyrolyzed carbon matrix (9.56 µm), and finally to a heterogeneous Mn-modified system with bimodal particle distribution (~25 µm and ~0.85 µm), the latter being associated with highly dispersed MnOx redox-active domains. Structural and textural analyses reveal that Mn incorporation significantly enhances surface properties, increasing the BET surface area from 140.8 to 213 m² g⁻¹ while reducing pore size to the meso–microporous range (~1.9 nm). Importantly, the material retains intrinsic minerals such as Ca, Mg, K, and Si, which contribute to surface basicity and ion-exchange capacity, supporting additional Hg(II) interaction pathways. Optical and electronic characterization shows a wide band gap semiconductor behavior (≈3.4 eV) and a conduction band position at −0.892 V vs. NHE, sufficiently negative to thermodynamically drive Hg²⁺ reduction to Hg⁰ under UV-A irradiation. Hg(II) quantification was validated using a UV–Vis method based on the Hg²⁺–dipicolinic acid (DPA) complex, confirming stable complex formation with 1:2 stoichiometry (Hg²⁺:DPA) and high analytical reliability (R² = 0.948, LOD = 1.85 mg L⁻¹). Photocatalytic experiments demonstrated negligible Hg(II) reduction under UV-A light in the absence of catalyst, whereas the carbon-based materials enabled significant Hg transformation through adsorption-assisted photoinduced electron transfer. Electrochemical analyses (Rct ≈ 11 Ω) confirmed efficient charge transport, while cyclic voltammetry evidenced reversible Mn(IV)/Mn(III)/Mn(II) redox cycling, which sustains electron mediation during photocatalysis. Overall, pristine biochar acts primarily through adsorption driven by oxygenated functional groups and porous structure, whereas Mn-functionalized biochar operates via a synergistic adsorption–photocatalytic mechanism. In this system, MnOx species function as redox-active centers that facilitate electron transfer from the carbon matrix to Hg(II), while the conductive lignocellulosic-derived framework enhances charge mobility. The combination of structural carbon stability, dispersed Mn active sites, and inherent mineral functionality establishes a highly efficient and sustainable carbocatalyst, demonstrating a green and scalable approach for mercury remediation in mining-impacted regions. Full article

Ammonium nitrogen pollution presents a significant challenge in wastewater treatment. Traditional activated sludge processes often suffer from limitations such as low efficiency and high energy consumption when treating high-ammonium nitrogen wastewater. This study utilized previously screened high-efficiency heterotrophic nitrification aerobic denitrification (HN-AD) bacterial strains (Pseudomonas alcaliphila and Paracoccus versutus) synergistically with microalgae to construct an immobilized bacteria algae symbiotic system (IBAS). The nitrogen removal performance and microbial community response of the system were investigated under different nitrogen sources, carbon to nitrogen (C/N) ratios, and light intensities. Results demonstrated that the system achieved a removal rate of over 95% for nitrite and nitrate. Under conditions of C/N = 15 and high light intensity (335.36 μmol/(m² · s)), the removal rates of NH₄⁺-N, TN, and COD exceeded 90% without nitrite accumulation. Microbial community analysis revealed that high C/N conditions significantly enriched HN-AD functional bacteria (such as Acinetobacter) in the Pseudomonadota phylum and Gammaproteobacteria class. High light intensity promoted the proliferation of microalgae (Chlorella and Halochlorella), enhanced algal bacterial interaction, and improved system stability. This study elucidated the nitrogen removal mechanism of the IBAS under multi-factor regulation, providing a theoretical foundation and demonstrating application potential for low-carbon and high-efficiency wastewater treatment technologies. Full article

This study proposes a novel synergistic design strategy to enhance the oxidation resistance of FeNiCuAl-based high-entropy alloys by integrating multi-element alloying (Cr-Co-Mn), trace Y modification, and laser-cladding-induced nanocrystallization. While the Base Alloy exhibited a mass gain of approximately 15 mg/cm² after oxidation at 900 °C for 120 h, the addition of Cr_2.5Co_2.5Mn_2.5 promoted the formation of a multilayered oxide scale (outer MnCr₂O₄/inner Al₂O₃), reducing the parabolic oxidation rate constant to 1.7 × 10⁻⁵ mg²·cm⁻⁴·s⁻¹. The originality of this work lies in the coupling of compositional and microstructural engineering; further addition of 0.5 at.% Y decreased this constant to 1.7 × 10⁻⁶ mg²·cm⁻⁴·s⁻¹—a three-order-of-magnitude reduction relative to the Base Alloy, while increasing the apparent oxidation activation energy to ~350 kJ/mol. After 100 thermal cycles at 1000 °C, the designed alloy showed a mass change of only 0.05 ± 0.02 mg/cm², with its critical load and interfacial fracture energy reaching 78 N and 14.8 J/m², respectively. Furthermore, the alloy retained a hardness of 310 HV, an elastic modulus of 135 GPa, and a tensile strength of 240 MPa at elevated temperature. These results demonstrate that the synergistic integration of chemical and structural optimization provides a new paradigm for designing low-cost, high-performance FeNiCuAl-based protective coatings. Full article

p-nitrophenol (p-NP) is a pollutant with environmental persistence, bioaccumulation potential, and significant health risks, and is widely dispersed in wastewater, so efficient removal of p-NP is imperative. Among the various methods, the catalytic reduction of p-NP to p-aminophenol (p-AP) using sodium borohydride (NaBH₄) is a particularly promising one and, herein, catalysts play a crucial role. Among the various metals, Au shows unique catalytic activity for p-NP reduction. However, nanosized Au often exhibit limited activity and stability due to their high surface free energy. To address this challenge, we designed and synthesized Au-SnO_x hybrid nanoparticles confined within hollow mesoporous silica nanoreactors (Au-SnO_x@hm-SiO₂) via a soft-template-assisted co-adsorption strategy. The resulting bimetallic Au-SnO_x@hm-SiO₂ nanoreactor showed significantly enhanced catalytic activity toward the NaBH₄-mediated reduction of p-nitrophenol (p-NP) compared with its monometallic Au@hm-SiO₂ counterpart, owing to the synergistic effect between Au and SnO_x. Among various Au/Sn ratios, the catalyst with an Au/Sn molar ratio of 1:0.1 demonstrated the highest activity, achieving complete conversion of p-NP within 5 min at a p-NP/Au molar ratio of 529:1—a tenfold improvement over Au@hm-SiO₂. Moreover, the catalyst maintained high efficiency over six consecutive cycles, with only slight deactivation, benefiting from the protective silica shell. Full article

Bone grafting remains limited, and the strategies to design even more structurally complex scaffolds—able to reproduce the hierarchical architecture of bone extracellular matrix—are rapidly growing. In this study, we report the fabrication of a hierarchically structured scaffold produced by layering poly(ε-caprolactone)/gelatin (PCL/Gt) or poly(lactic acid)/gelatin (PLA/Gt) electrospun nanofibers via coaxial electrospinning onto 3D-printed poly(lactic acid) (PLA) scaffolds via fused deposition modeling (FDM). After the printing process, PLA disks (10 × 1 mm, 20% infill, ~80% porosity, pore size ~1.57 mm) were coated with core/shell (PCL/Gt, PLA/Gt) fibers to investigate the in vitro interfacial response of osteoblasts in comparison with monocomponent fibrous coatings (PCL, PLA, Gt). SEM and TEM confirmed that core/shell fibers exhibited bead-free morphologies, with a significant reduction in fiber diameter (≈287–316 nm) and higher interfibrillar porosity compared to monocomponent fibers. FTIR and thermogravimetric analyses indicated the presence of hydrogen bonding between the polyester and gelatin, and the absence of residual solvent after deposition. At the same time, water contact angle measurements confirmed an increase in hydrophilic properties from 80–86° to 120° ascribable to the presence of gelatin. Accordingly, in vitro response of human fetal osteoblasts (hFOB 1.19) exhibited an evident improvement in the case of Gt-based fibrous coatings (i.e., PCL/Gt and PLA/Gt) in terms of early adhesion (4–24 h) and metabolic activity from 3 to 21 days, cell spreading into star-shaped morphologies, formation of extracellular matrix, and mineral phase deposition. In more detail, a remarkable increase in alkaline phosphatase activity was observed in Gt-based coaxial coatings from day 7 onward, with the highest values recorded for PLA/Gt. Overall, we demonstrated that the Gt-based coaxial fibrous coating provided a mix of topological and biochemical cues that synergistically promoted key osteoblast activities at the interface, supporting the regeneration of new bone tissue in highly tailored 3D-printed scaffolds, thus suggesting a promising strategy for personalized regenerative medicine. Full article