Search Results (29,890)

This research presents a novel methodology to classify copper tailings according to their potential as alkali-activated materials (AAMs) for construction applications. The methodology includes geochemical and mineralogical characterization via QEMSCAN and X-ray fluorescence, with mechanical performance evaluation through compressive strength test (UCS). A three-phase diagram based on Al₂O₃, Fe₂O₃, and CaO-MgO-K₂O is proposed for a fast screening of copper tailing potential to be used as a construction material. In this paper, three copper tailings were chosen to test the methodology, and a set of five samples for each tailing have been geopolymerized for testing. Copper tailing samples were mixed with 0, 2.5, 5, 7.5 and 10% by mass of Ordinary Portland Cement (OPC) to evaluate the effect on performance when a chemical co-activator is used to improve material reactivity. Compressive strength testing was applied on 2 cm³ cubes after 28 days of curing at 60 °C, yielding values from 6 to 26.1 MPa. The best performing sample featured a Si/Al ≅ 3 ratio and a mineralogy with significant presence of reactive species such as plagioclase and K-feldspar (≅42%). In contrast, high levels of Fe₂O₃ (≥12%), clay (≥7%), and pyrite (≥4%) were associated with reduced mechanical performance. Full article

High-calcium fly ash (HCFA), produced from the lignite combustion, has emerged as a global concern due to its fine particle size and adverse environmental impacts. This study presents the characteristics of dispersed microspheres from HCFA obtained using modern techniques, such as XRD, SEM-EDS, ⁵⁷Fe Mössbauer spectroscopy, DSC-TG, particle size analysis, and magnetic measurements. It is found that an increase in microsphere size is likely due to the growth of the silicate glass-like phase, while the magnetic crystalline phase content remains stable. According to the ⁵⁷Fe Mössbauer spectroscopy, there are two substituted Ca-based ferrites—CaFe₂O₄ and Ca₂Fe₂O₅ with a quite different magnetic behavior. Besides, the magnetic ordering temperature of the brownmillerite (Ca₂Fe₂O₅) phase increases with the average diameter of the microspheres. FORC analysis reveals enhanced magnetic interactions as microsphere size increases, indicating an elevation in the concentration of magnetic microparticles, primarily on the microsphere surface, as supported by electron microscopy data. The discovered the magnetic crystallographic phases distribution on the microsphere’s surface claims the accessibility for further enrichment of the magnetically active particles and the possible application of fly ashes as a cheap source for magnetic materials synthesis. Full article

Microminerals such as cobalt (Co), copper (Cu), iodine (I), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se), and zinc (Zn) play key roles in cattle health. However, trace element imbalances are often underdiagnosed. This study retrospectively analyzed serum samples from 1273 cows across 117 herds in Spain, encompassing conventional dairy (n = 46), pasture-based dairy (n = 11), organic dairy (n = 25), and semi-extensive beef (n = 35) systems. Trace elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). All herds were investigated for clinical or productive issues where mineral deficiencies were suspected. Significant differences were found in serum trace mineral concentrations between production systems. Adequacy rates were highest in conventional dairy herds receiving routine mineral supplementation, while deficiencies in Se, I, and Cu were frequently detected in pasture-based, organic, and beef herds. Zinc deficiencies were rare and typically involved complex, combined deficiencies. At the farm level, multielement deficiencies (≥3 elements) were detected in 39–45% of organic, pasture-based, and beef herds, but in only 5% of conventional dairy herds (p < 0.001). Principal component and cluster analyses produced consistent groupings of minerals according to dietary supplementation and soil-driven exposure. These findings highlight the increased vulnerability of low-input systems to complex micromineral imbalances and underline the importance of system-adapted mineral-monitoring and supplementation strategies in herd health management. However, as the study is based on diagnostic submissions rather than a randomized herd survey, the findings should be interpreted with caution due to potential selection bias. Full article

Little information is available on the yellow-fleshed Zespri Zesy002 kiwifruit dynamic of mineral nutrient uptake and partitioning within organs. The aim of the present experiment was to find nutrient requirements and supply data for a specific nutrient management plan for Zesy002. The trial was conducted, for three years, in northern Italy, on a six-year-old kiwifruit orchard of the variety Zespri Zesy002. During the experiment organs were periodically sampled and analyzed for macro- and micronutrient concentration. A yearly nutrient uptake of 175 g N plant⁻¹, 16 g P plant⁻¹, 138 g K plant⁻¹, 235 g Ca plant⁻¹, 48 g Mg plant⁻¹, 17 g S plant⁻¹, 247 mg B plant⁻¹, 673 mg Cu plant⁻¹, 5.20 g Fe plant⁻¹, 473 mg Mn plant⁻¹, and 263 mg Zn plant⁻¹ was calculated, confirming that kiwifruit is a high-nutrient-demanding species. The nutrients found in the tree organs were divided in two factions: removed (not returned into the soil) and recycled (returned into the soil during and at the end of the growing cycle). The two fractions were similar for N, P, K, S, and Mn. The fraction recycled of Ca, Mg, Cu, and Zn was higher than the fraction removed, and the reverse was observed for Fe. These data created the basis for the determination of the correct nutritional plans that take into consideration not only nutrient requirements but also the dynamics of uptake during the season. Full article

Gelatin from bovine hide, especially yak hide, is valued in the food and pharmaceutical industries; however, as the most common domestic cattle in China, gelatin made from yellow cattle hide remains unexplored. Thus, the physicochemical properties, nutritional components, and flavor characteristics of gelatin produced from yellow cattle hides and yak hides, both before and after hair removal, were analyzed. It was found that yellow cattle hide gelatin (YCHG) not only had a higher protein content (68.45–71.51%) than yak hide gelatin (YHG) (66.81–67.56%) but also had a higher Fe content (86.75 ± 1.650 mg/kg). Additionally, 17 amino acids were detected in the four bovine hide gelatin samples; among them, dehaired yellow cattle hide gelatin (DYCHG) was richer in sweet-tasting amino acids than the others. Notably, non-dehaired yellow cattle hide gelatin (NDYCHG) featured 4-methyl-3-penten-2-one (with a honey aroma), whereas non-dehaired yak hide gelatin (NDYHG) featured β-pinene, 1-nonanal, acetic acid-D, (E)-2-pentenal, and allyl sulfide. Therefore, yellow cattle hide gelatin (YCHG) exhibits prominent nutritional and flavor properties, suggesting its potential as an alternative raw material for food industry applications. Full article

This study develops a four-dimensional value-assessment framework encompassing economic, innovation, social, and cultural dimensions to evaluate the multidimensional performance of family firms in China. Drawing on the entropy weighting method, we construct a composite value index for 251 A-share listed family firms from 2014 to 2023 and apply spatial statistical techniques—including Dagum Gini coefficients, Theil indices, and coefficients of variation—to examine temporal evolution and regional disparities. We further estimate explanatory panel models with firm and year fixed effects (Hausman test favoring FE) to identify the firm-level determinants of composite value. Leverage exhibits a significantly negative association with value, while firm size and innovation capacity are positively related; no significant moderating effect of technology-intensive industry is found. A robustness check using equal weights (0.25 for each dimension) yields an almost perfect correlation (0.9999) with the entropy-weighted index, confirming that the dominance of the innovation dimension in the weighting scheme does not materially affect the overall conclusions. The results highlight the importance of integrating multidimensional value perspectives into both academic research and policy design to promote balanced, inclusive, and sustainable development trajectories for family enterprises. Full article

This review aims to provide a comprehensive overview of how oxidative stress drives inflammation, structural remodeling, and clinical expression of childhood asthma, while critically appraising emerging redox-sensitive biomarkers and antioxidant-focused preventive and therapeutic strategies. Oxidative stress arises when reactive oxygen species (ROS) and reactive nitrogen species (RNS) outpace airway defenses. This surplus provokes airway inflammation: ROS/RNS activate nuclear factor kappa-B (NF-κB) and activator protein-1 (AP-1), recruit eosinophils and neutrophils, and amplify type-2 cytokines. Normally, an antioxidant network—glutathione (GSH), enzymes such as catalase (CAT) and superoxide dismutase (SOD), and nuclear factor erythroid 2-related factor 2 (Nrf2)—maintains redox balance. Prenatal and early exposure to fine particulate matter <2.5 micrometers (µm) (PM_2.5), aeroallergens, and tobacco smoke, together with polymorphisms in glutathione S-transferase P1 (GSTP1) and CAT, overwhelm these defenses, driving epithelial damage, airway remodeling, and corticosteroid resistance—the core of childhood asthma pathogenesis. Clinically, biomarkers such as exhaled 8-isoprostane, hydrogen peroxide (H₂O₂), and fractional exhaled nitric oxide (FeNO) surge during exacerbations and predict relapses. Therapeutic avenues include Mediterranean-style diet, regular aerobic exercise, pharmacological Nrf2 activators, GSH precursors, and mitochondria-targeted antioxidants; early trials report improved lung function and fewer attacks. Ongoing translational research remains imperative to substantiate these approaches and to enable the personalization of therapy through individual redox status and genetic susceptibility, ultimately transforming the care and prognosis of pediatric asthma. Full article

This work investigated the effect of high-nitrogen/low-hydrogen mixed atmosphere heat treatment on the electrochemical corrosion and wear resistance of plasma-sprayed FeCoNiCrAl high-entropy alloy (HEA) coatings. The HEA coatings were sequentially prepared through annealing at 400, 600, and 800 °C for 6 h. The heat treatment method was conducted in a vacuum tube furnace under 0.1 MPa total pressure, with gas flow rates set to 300 sccm N₂ and 100 sccm H₂. The XRD results indicated that the as-deposited coating exhibited α-Fe (BBC) and Al_0.9Ni_4.22 (FCC) phases, with an Fe_0.64N_0.36 nitride phase generated after 800 °C annealing. The electrochemical measurements suggested that an exceptional corrosion performance with higher thicknesses of passive film and double-layer capacitance can be detected based on the point defect model (PDM) and effective capacitance model. Wear tests revealed that the friction coefficient at 800 °C decreased by 3.84% compared to that in the as-sprayed state due to the formation of a dense nitride layer. Molecular orbital theory pointed out that the formation of bonding molecular orbitals, resulting from the overlap of valence electron orbitals of different atomic species in the HEA coating system, stabilized the structure by promoting atomic interactions. The wear mechanism associated with stress redistribution and energy balance from compositional synergy is proposed in this work. Full article

Tryptophan hydroxylase 2 (TPH2) hydroxylates L-tryptophan to L-5-hydroxytryptophan (5-HTP) the first and rate-limiting step of serotonin (5-HT) synthesis in the mammalian brain. Some mutations in the Tph2 gene reducing TPH2 activity are associated with hereditary depressive disorders. The P447R substitution in the mouse TPH2 molecule reduces its thermal stability in vitro and its activity in the brain. The effects of iron ions on thermal stability in vitro and the activity in the brain of the mutant TPH2 were investigated. In the in vitro experiment effects of 0.01, 0.05, and 0.2 mM of FeSO₄ and FeCl₃ on the enthalpy (ΔH) and Gibbs free energy (ΔG) of thermal denaturation of the mutant TPH2 extracted from the midbrain of Balb/c mice were assayed. All FeSO₄ concentrations and 0.05 and 0.2 mM concentrations of FeCl₃ increased these thermodynamic characteristics of the mutant TPH2. Repeated (for 7 days) intramuscular administration of Fe(III) hydroxide dextran complex (15 and 30 mg/kg/day) increased TPH2 activity in the hippocampus, but not in the midbrain in Balb/c mice. Repeated (for 7 days) intramuscular administration of Fe(III) hydroxide dextran complex (15 and 30 mg/kg/day) together with thiamine (8 mg/kg/day) and cyanocobalamin (0.8 mg/kg/day) increased TPH2 activity in the hippocampus, while 30 mg/kg of Fe(III) hydroxide dextran also increased the enzyme activity in the midbrain in Balb/c mice. These results are the first evidence for chaperone-like effects of iron ions on thermal stability in vitro and activity in the brain of the mutant TPH2. Full article

Pervious concrete is a promising sustainable pavement material for sponge city construction. The incorporation of Steel Slag Aggregate (SSA) as a substitute for natural aggregates has the double role of clean production with significant economic and environmental benefits. While the strength and permeability, known as two critical design parameters of pervious concrete, are closely linked to its porosity, there is limited research on the influence of the porosity on the mechanical properties of pervious concrete. In this paper, both experimental and numerical investigations were performed, focusing on the influence of target porosity on the strength and permeability of pervious concrete with and without SSA. Three different target porosities (15%, 20%, and 25%), five distinct water-to-cement (w/c) ratios (0.25, 0.28, 0.30, 0.33, and 0.35), and five SSA replacement ratios (0, 25%, 50%, 75%, and 100%) were considered in this study. A two-dimensional (2D) finite-element (FE) model was developed, with which the failure mode and the strength variation of pervious concrete under different target porosities were analyzed and verified with the experimental results. The results showed that the porosity had a significant influence on both the strength and permeability of pervious concrete, while the influence of the w/c ratio is marginal. There existed an optimal w/c ratio of 0.3, for which pervious concrete with porosities of 15%, 20%, and 25% achieved 28-day compressive strengths of 27.8, 20.6, and 15.6 MPa and permeability coefficients of 0.32, 0.58, and 1.02 cm/s, respectively. Specifically, at the lowest porosity of 15%, the replacement of 100% SSA resulted in the largest improvement in the compressive strength up to 37.86%. Based on the regression analysis, a series of empirical equations correlating the porosity, strength and permeability of pervious concrete was formulated and validated against the experimental data. The findings presented herein are expected to provide references to the practical evaluation of the optimal mix proportion of previous concrete, considering specific and demanding engineering requirements. Full article

Cilantro (Coriandrum sativum L.) is a popular annual culinary herb grown for its leaves or seeds. With the increase in hydroponic herb production in controlled environments, a need exists for leaf tissue nutrient standards specific to this production system. The objective of this study was to develop comprehensive foliar mineral nutrient interpretation ranges for greenhouse-grown cilantro. Cilantro plants were grown in a hydroponic sand culture system to induce and document nutritional disorders. Plants were supplied with a modified Hoagland’s solution, which was adjusted to individually add or omit one nutrient per treatment while holding all others constant. Deficiency and toxicity symptoms were photographed, after which the plant tissue was collected to determine plant dry weight and critical tissue nutrient concentrations. Nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), boron (B), iron (Fe), and zinc (Zn) deficiencies, as well as B toxicity, were induced. Deficiencies of copper (Cu), manganese (Mn), and molybdenum (Mo) were not observed during the experiment. Additional foliar tissue analysis data (n = 463) were compiled to create nutrient interpretation ranges for 12 essential elements based on a hybrid meta-analysis Sufficiency Range Approach (SRA). This approach defines ranges for deficient, low, sufficient, high, and excessive values. For each element, the optimal distribution was selected according to the lowest Bayesian Information Criterion (BIC) value. A Normal distribution best represented K and S. A Gamma distribution best represented P, Ca, Mn, and Mo, whereas a Weibull distribution best represented N, Mg, B, Cu, Fe, and Zn. These interpretation ranges, along with descriptions of typical symptomology and critical tissue nutrient concentrations, provide useful tools for both diagnosing nutritional disorders and interpreting foliar nutrient analysis results of greenhouse-grown cilantro. Full article

Type 2 diabetes mellitus (T2DM) and metabolic syndrome (MS) are chronic disorders characterized by hyperglycemia. Sechium edule (S. edule) has emerged as a complementary option due to its bioactive compounds. A systematic review of preclinical and clinical studies was carried out until 25 May 2025 in the databases PubMed, Scopus, Web of Science, SciELO, and TESIUNAM. The keywords were “diabetes mellitus”, “Sechium edule”, “Squash”, “Chayote”, “hypoglycemic effect”, and “Older adults”. A total of 110 articles were found; 11 met eligibility criteria (six clinical trials and five preclinical trials). Three clinical trials met the requirements for meta-analysis. The mean difference (MD) was calculated, and data were analyzed using RevMan 5.4 software. The meta-analysis showed a statistically significant decrease in serum glucose after three months (MD = −20.56, 95%CI −29.35 to −11.77, p < 0.0001) and six months after intervention (MD = −12.96, 95%CI = −21.90 to −4.02, p = 0.004). Likewise, there was a significant decrease in glycosylated hemoglobin (HbA1c) after three months (MD = −1.12, 95% CI = −1.45, −0.78, p < 0.0001) and after six months of intervention (MD = −0.92, 95% CI = −1.13, −0.25, p = 0.002). Our findings showed that S. edule intake has a statistically significant hypoglycemic effect in older adults with T2DM or MS by decreasing serum glucose and HbA1c levels. However, the magnitude of the decrease is clinically modest, so it cannot be a substitute for pharmacological treatment. For this reason, the intake of S. edule can only be considered as a complement to pharmacological treatment. Full article

This study evaluates and compares the sorption performance of natural zeolite (NZ) and Fe(III)-modified zeolite (FeZ) in removing Cu(II) ions from aqueous solutions, with the goal of assessing their potential for environmental remediation. NZ was modified with Fe(NO₃)₃, NaOH and NaNO₃ solutions to improve its sorption properties. The modification led to a slight decrease in crystallinity (XRD), increase in pore volume (BET), functional groups (FTIR) and negative surface charge (zeta potential), thereby improving the affinity of FeZ towards Cu(II). Batch sorption experiments were conducted to optimize key parameters including pH, solid/liquid ratio (S/L), contact time, and initial Cu(II) concentration. The pH_o and S/L ratio were identified as key factors significantly influencing Cu(II) sorption on both zeolites, with a particularly pronounced effect observed for FeZ. The optimal conditions determined were pH_o = 3–5 for NZ, pH_o = 3 for FeZ, S/L = 10 g/L and a contact time of 600 min. Experimental results confirmed that FeZ has almost twice the sorption capacity for Cu(II) compared to NZ (0.271 mmol/g vs. 0.156 mmol/g), as further supported by elemental analysis, SEM-EDS and mapping analysis of saturated samples. The sorption of Cu(II) followed a mechanism of physical nature driven by ion exchange, dominated by intraparticle diffusion as the rate-controlling step. Leaching of copper-saturated zeolites according to the standard leaching method, DIN 38414 S4, demonstrated the ability of both zeolites to fully retain Cu(II) within their structure over a wide pH range, 4.01 ≤ pH_o ≤ 10.06. These findings highlight the superior performance of FeZ and its potential as an effective material for the remediation of copper-contaminated environments. Full article

To enhance surface hardness, laser surface remelting (LSR) was performed to treat the surface of a novel nuclear-grade Zr-1.0Sn-1.0Nb-0.3Fe zirconium alloy. A combination of advanced characterization techniques was used to systematically analyze the microstructural features of the samples before and after the LSR treatment, and their correlation with hardness variations was studied. Results show that the LSR-treated surface consists of two distinct microstructural regions: (i) the remelted zone (RZ), characterized by fine lath structures and precipitates distributed along the lath boundaries; and (ii) the heat-affected zone, comprising blocky α phase, α laths, and precipitates. The surface of the LSR-treated samples exhibits a random texture, which is attributed to the selection suppression of α variants during the laser-induced rapid transformation. The average hardness of the RZ reaches 285.7 ± 8.3 HV, ~40% higher than the substrate. This hardness enhancement is ascribed to LSR-induced grain refinement. Full article

Stuffing sand, as a critical auxiliary material, plays an important role in ladle teeming during the continuous casting process and is closely related to steel cleanliness. Based on thermodynamic calculations, a melting test in a vacuum induction furnace, and industrial statistical data analysis, the reoxidation of IF steel caused by conventional Cr₂O₃-based stuffing sand was investigated. The results show that Cr₂O₃-based stuffing sand is one of the main factors resulting in the reoxidation of IF steel. [Al] and [Ti] in IF steel can be oxidized by FeO, Cr₂O₃, and SiO₂ from the Cr₂O₃-based stuffing sand, which leads to the mass burning loss of [Al] and [Ti], thus resulting in the deterioration of steel cleanliness. After reoxidation caused by Cr₂O₃-based stuffing sand, the [Cr] content in IF steel increases by 70 ppm on average. To avoid reoxidation pollution by conventional Cr₂O₃-based stuffing sand, a new kind of Al₂O₃-based stuffing sand with low reactivity was developed and applied in industrial production. After adopting this new kind of stuffing sand, the burning loss of [Al] and [Ti] decreases by 41.3% and 24.2%, respectively, and the total oxygen content (T.[O]) of the steel in the tundish decreases by 35.2% compared with the conventional Cr₂O₃-based stuffing sand. Full article