Search Results (1,703)

Calcium (Ca) deficiency is a major nutritional constraint for sugarcane, impairing stoichiometric homeostasis and biomass accumulation. In this context, silicon dioxide nanoparticles (nSiO₂) have emerged as a promising alternative due to their high reactivity and potential to modulate mineral homeostasis. This study evaluated the effects of nSiO₂ on C:N:P:Si homeostasis and on nutrient uptake, translocation, and use efficiencies in sugarcane plants grown under Ca deficiency and sufficiency. The experiment was conducted in a greenhouse using a 2 × 2 factorial design, with two Ca conditions (0 and 3 mmol L⁻¹) and two nSiO₂ conditions (0 and 1.77 mmol L⁻¹ of Si), with four replications. Calcium deficiency reduced nutrient accumulation and nutritional efficiencies of several macro- and micronutrients, disrupted stoichiometric ratios, and decreased shoot dry mass. The application of nSiO₂ under Ca deficiency increased Si concentration and accumulation along with other nutrients, reduced C:Si ratios, enhanced nutrient uptake, translocation, and use efficiencies, and resulted in increased shoot biomass. Under Ca-sufficient conditions, nSiO₂ promoted nutritional adjustments and improved nutrient efficiencies but did not affect biomass production. Overall, the results demonstrate that nSiO₂ acts as a nutritional modulator and is more effective in mitigating the adverse effects of Ca deficiency through stoichiometric rebalancing and improved nutrient use efficiencies. Full article

Magnetoelectric (ME) materials that exhibit simultaneous coupling between electric polarization and magnetization have attracted significant attention due to their potential technological applications in the emerging generation of multifunctional devices. In this research, Ba_0.85Ca_0.15Ti_0.92Zr_0.08O₃-CoFe₂O₄:x (x = 0.1, 0.2, 0.3% mol) composites were synthesized using solid-state and sol–gel combustion chemical methods to elucidate their ME coupling at ultra-low concentrations of the magnetic phase. Rietveld refinement and Raman spectroscopy results confirm a shift in the morphotropic phase boundary (MPB), evidenced by an increase in the tetragonal phase relative to the orthorhombic structure. High stability of the P4mm and Amm2 symmetries is reached at 1300 °C without diffusion of Fe and Co into the octahedral site. At this temperature, the CoFe₂O₄ spinel structure remains stable without secondary phases. The orthorhombic phase fraction decreases from 55% to 37% as the magnetic phase fraction increases, driven by stress and constraint rather than ionic interactions alone. The Curie temperature decreases from 99 to 90 °C, attributed to the grain-size reduction effect rather than structural disorder. The dielectric permittivity (ε_r) reaches an absolute value of 5070 and progressively decreases with increasing magnetic saturation. An increase in compressive residual stress is observed, which ensures the mechanical stability of the electroceramics. Magnetoelectric (ME) coupling, evaluated through measurements of electric polarization as a function of the magnetic field, shows an increase from 3.8 to 4.9 μC/cm² under a magnetic field of 50 Oe. The composites with x = 0.2 and 0.3 mol% exhibit potential for applications in fast-switching magnetoelectric devices and magnetic field sensors. Full article

Accurately tracing the geographical origin of Zanthoxylum schinifolium Sieb. et Zucc. is important for brand authentication, quality control, and food safety assurance. In this study, the stable isotope ratios (δ¹³C, δ¹⁵N, δ²H, δ¹⁸O) and the contents of 20 elements were analyzed in samples from three major production regions. Significant differences (p < 0.05) were observed in δ¹³C, δ²H, δ¹⁸O and most elemental profiles across origins. Chemometric methods—including principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and linear discriminant analysis (LDA)—were applied to classify samples by geographical origin. OPLS-DA identified key discriminators (VIP > 1) such as Ca, δ¹³C, Mg, δ²H, B, δ¹⁸O, Cr, Ni, Na, Pb, As, Co, Se, and Zn, achieving a classification accuracy of 96.8%. LDA based on the combined isotope and element datasets showed even higher performance, with an original discrimination rate of 98.4% and a cross-validated rate of 92.8%. The results demonstrate that integrating stable isotope and multi-element fingerprints with supervised classification models provides a reliable and effective approach for verifying the geographical origin of Zanthoxylum schinifolium, supporting its use in traceability systems and fair trade practices. Full article

Given the rising demand for phosphate, a critical mineral for many countries due to its essential role in fertilizer production and global food security, reprocessing waste generated during phosphate mining has become increasingly important to mitigate demand pressures and reduce the environmental impact of the mining industry. This study aims to develop a sustainable hydrometallurgical process to recover residual phosphate from a lithology present in mining waste rock. To this end, a thermodynamic analysis was first performed to assess reaction feasibility during leaching and precipitation. A two-step process was then proposed: the first step involves leaching carbonates (mainly calcite) using acetic acid, optimized through response surface methodology based on a Box–Behnken design; the second step consists of precipitating calcium with phosphoric acid to produce a value-added by-product (brushite) while simultaneously regenerating the acetic acid. A preliminary economic assessment was conducted to evaluate process feasibility. The results show that acetic acid is highly selective for carbonates, yielding a phosphate concentrate containing 30% P₂O₅ with complete phosphate recovery under the following conditions: 3.4 molL⁻¹ acid concentration, 28 °C reaction temperature, a liquid-to-solid ratio of 6 mLg⁻¹ (14.2% solids), and a reaction time of 49 min. In the precipitation step, a calcium recovery of 97% was achieved under optimal conditions (20 °C, 15 min, 500 rpm stirring, and a P:Ca ratio of 1). Furthermore, the preliminary economic assessment indicates that the developed process, based on the use of an organic acid and its recycling, generates a net profit, confirming its economic viability and its contribution to environmentally sustainable phosphate processing. Full article

To promote the high-value utilization of fly ash (FA) and address the prolonged setting time and limited strength associated with conventional single-alkali activation, this study proposes a synergistic dual-alkali activation strategy using Ca(OH)₂ and Na₂SiO₃ in combination with microwave-assisted curing for low-calcium fly ash. Samples containing varying amounts of Ca(OH)₂ were systematically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), compressive strength testing, and pore structure analysis. The results show that Ca(OH)₂ facilitates the formation of calcium aluminosilicate hydrate (C-A-S-H) gel, while Na₂SiO₃ sustains the alkaline environment and enhances the dissolution of SiO₂ and Al₂O₃ from FA. The dual-alkali synergistic system, when coupled with microwave treatment, markedly refines the pore structure, increases the degree of polymerization, and improves compressive strength from 0.5 MPa to 1.7 MPa with increasing Ca(OH)₂ content. In addition, the prepared fly ash-based geopolymer (FABG) demonstrates pronounced pH-buffering capacity in acidic environments and exhibits antibacterial activity, primarily attributable to its sustained release of alkalinity. This work highlights that integrating dual-alkali activation with microwave curing can simultaneously enhance microstructural development, chemical stability, and functional performance in low-calcium FA systems, thereby offering a viable route for the development of sustainable and multifunctional green building materials derived from industrial solid waste. Full article

Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare autosomal recessive disorder characterized by hyperphosphatemia and ectopic calcifications. Mutations in GALNT3, which encodes a key enzyme responsible for O-glycosylation of FGF23, represent a major genetic cause of HFTC. This modification is essential for the stability and secretion of FGF23. We investigated a 4-year and 6-month-old Chinese girl with HFTC to characterize the clinical features, identify the causative variants, and explore the underlying pathogenic mechanism. Whole-exome sequencing followed by Sanger validation identified novel compound heterozygous variants in GALNT3 (c.659T>A, p.Ile220Asn and c.1850C>A, p.Ser617*). The patient exhibited hyperphosphatemia with a biochemical profile consistent with FGF23 deficiency, including extremely low intact FGF23 and elevated C-terminal fragments. Functional studies using Western blotting and wheat germ agglutinin affinity chromatography demonstrated that the mutant GALNT3 caused a severe defect in FGF23 O-glycosylation, leading to impaired secretion of intact FGF23. Glycosylated FGF23 was detected only in the medium of cells expressing wild-type GALNT3. These findings indicate that defective O-glycosylation results in failure of FGF23 secretion and functional inactivation. This study expands the mutational spectrum of GALNT3 and provides mechanistic insight into the role of GALNT3 in phosphate homeostasis. Full article

The organization of safe industrial waste management is an integral part of the global sustainable development strategy. This study provides a preliminary assessment of the processing and recycling potential of strongly alkaline (pH 11–12) sediments accumulated in an abandoned sludge pond (Berezniki, Perm Krai, Russia), based on the initial characterization of their material composition. Sediment samples from the sludge pond were collected, layer-by-layer, over the entire depths of four sediment cores. The collected samples have the following characteristics: sediment particles are composed of up to 80% fine particles < 0.05 mm, with up to 20% fine particles < 0.002 mm. XRD data showed that the sediment consisted of calcite (67.7 wt.%), halite (11.5 wt.%), and other hydrogenic and terrigenous minerals. XRF data also found that the primary constituents in the sediment are CaO (up to 40%), Cl (up to 13%), and LOI (up to 35%). The results of the material composition study indicate a high degree of similarity between the accumulated sediments and solid waste from soda ash production, known as ammonia–soda residue (ASR). Based on experience with calcium-containing waste, this study recommends options for the secondary use of sludge, identifying two main possibilities: environmental protection and construction. We have developed an algorithm for the recycling and reuse of sludge that identifies risks, limitations, and recommended next steps. However, significant knowledge gaps regarding the environmental, toxicological, and the physical–mechanical properties of sludge prevent us from recommending a specific disposal option. The results of this review will serve as guidelines to help develop a roadmap for the disposal process. They will also inform decision-makers about sustainability issues related to industrial waste disposal. Full article

In permanently submerged coastal wetlands, interactions between biogeochemical processes and microbial communities strongly influence greenhouse gas (GHG) fluxes. To improve our understanding of how redox-driven processes shape GHG dynamics in these ecosystems, we investigated the relationships among iron (Fe) pools, microbial dynamics, and the potential GHG production in subaqueous soils from an interdunal wetland in San Vitale Park (Italy), permanently submerged and affected by seasonal oscillations of the saline water table. Two subaqueous soil columns (WAS-2 and WAS-4), collected from similar settings, were analyzed. Surface layers of WAS-4 showed higher salinity and carbonate content, whereas WAS-2 was characterized by overall higher Fe concentrations. Distinct vertical distributions of organic matter and sulfur (S) were shown along depth. Laboratory incubations revealed that nitrous oxide (N₂O) production was up to ten times higher in WAS-2 than in WAS-4, with peaks in the top 13–14 cm, consistent with more active nitrification-denitrification in surface layers. Methane (CH₄) and carbon dioxide (CO₂) fluxes decreased with depth, reflecting reduced availability of labile carbon. Methanomicrobiales dominated CH₄-producing layers, indicating hydrogenotrophic methanogenesis, while amoA-carrying Nitrosomonadales and Thaumarchaeota, occurred in shallow, organic-rich layers where ammonia supported nitrification and denitrification. Denitrifiers mainly belonged to α- and β-Proteobacteria, consistent with their direct contribution to N₂O peaks. Spearman’s correlations showed N₂O positively correlated to sulfur and labile carbon (C), supporting denitrification under moderately reducing conditions. CH₄ and CO₂ positively correlated with organic C (Corg), total nitrogen (TN), and reactive Fe forms, reflecting redox-mediated microbial respiration and methanogenesis. Trace elements (B, Cr, Cu, Ni) acted as micronutrients or inhibitors depending on concentration. Canonical correspondence analysis indicated depth-structured links among gas fluxes, soil chemistry (Corg, TN, S/C, CaCO₃, P), and microbial distributions: surface layers, rich in labile C and nutrients, supported active bacteria and archaea involved in decomposition, nitrification, and denitrification, whereas deeper layers hosted oligotrophic archaea adapted to inorganic substrates. Overall, Fe pools appeared to be associated with soil processes relevant to GHG dynamics, although the extent of their regulatory role remains uncertain due to potential alterations of redox-sensitive Fe fractions during sample handling. These results contribute to broader efforts to predict GHG emissions in submerged wetland soils by linking redox stratification, inorganic chemistry, and microbial functional groups. Full article

Colorectal cancer (CRC) is still a leading cause of cancer-related death worldwide, and often, conventional chemotherapeutics exhibit limited efficacy. The hydroalcoholic leaf extract of Cynara cardunculus subsp. cardunculus (wild artichoke) was investigated for its anticancer potential in CRC and effects on enteric pathogens. Nine phenolic compounds were identified by high-performance liquid chromatography with diode-array detection (HPLC-DAD), and spectrophotometric analyses were applied for total phenolic (TPC: 178.33 mg GAE/g) and total flavonoid (TFC: 52.21 mg CE/g) content quantification. The extract exhibited good antioxidant activity on DPPH (IC₅₀: 21.35 μg/mL), ^−•O₂ (IC₅₀: 1.56 μg/mL), and H₂O₂ (IC₅₀: 314.73 μg/mL) and was found to inhibit the growth of pathogenic enteric bacteria, with Enterococcus faecalis and Staphylococcus aureus being the most sensitive. In CaCo-2 CRC cells, the extract induced a concentration-dependent cytotoxicity (IC₅₀: 13.07 μg/mL at 24 h) through increased production of reactive oxygen species (ROS), upregulation of Nrf2, and induction of apoptosis, as evidenced by elevated p53, Bax, cytochrome c, and caspase-3 levels. No necrosis, measured by lactate dehydrogenase (LDH) release, or toxicity to HFF-1 normal fibroblasts was observed at concentrations up to 50 μg/mL. Additionally, CCE demonstrated synergistic effects with 5-FU (combination index < 0.8). This evidence suggests that CCE exhibits selective antitumor activity and chemosensitizing properties, supporting its possible development as an adjunctive agent in CRC therapy. Full article

The application of leguminous green manure (GM) can enhance the soil inorganic phosphorus (Pi) pool, offering considerable benefits for crop cultivation in slightly and moderately saline-alkali soils. To optimize its agronomic potential, systematic and science-based fertilization strategies are required. In this study, we researched the changes in the content, movement distance, and accumulation of Pi fractions at the GM microsites in coastal saline-alkali soils of differing salinity levels (slightly vs. moderately) following the application of Sesbania GM at two rates (30 and 60 t ha⁻¹) over 14- and 28-day incubation periods. The results indicated that GM application significantly (p < 0.05) increased the accumulation of all Pi fractions—including aluminum-bound phosphorus (Al-P), iron-bound phosphorus (Fe-P), occluded phosphorus (O-P), and forms of calcium-bound Pi (Ca-P: Ca₂-P, Ca₈-P, and Ca₁₀-P)—at the manure microsite, with the magnitude of increase declining with distance from the manure site. Further analysis revealed positive correlations between GM rate, two incubation periods and Pi-fraction movement distance, indicating that the observed effects were significantly influenced by incubation period, GM rate, and soil salinity-alkalinity. While temporal dynamics governed the rates of Pi movement and transformation, elevated salinity-alkalinity partially inhibited these processes. This study provides practical insights for improving GM utilization efficiency on saline-alkali soils. These results support optimized GM application to enhance P efficiency and reduce fertilizer reliance in saline systems. Full article

This study aimed to prepare experimental calcium silicate repair cements (ERCs) incorporating zirconium (Ca₃ZrSi₂O₉; CZS) or strontium substitution (Sr₅(PO₄)₂SiO₄; SPS), and to compare their physicochemical properties with white MTA-Angelus (WMTA), grey MTA-Angelus (GMTA), and Biodentine (BD). After synthesizing the CZS and SPS phases, powder–liquid cements were formulated. The setting time and radiopacity were assessed according to ISO 6876/12 and ASTM C266, the volumetric solubility by micro-CT, the pH by a pH meter, and the calcium/strontium ion release by FAAS/ICP-OES. Data were analyzed using ANOVA and Tukey’s tests (5%). The initial setting time was 11 min for SPS and 6 min for CZS (p < 0.05), while the final setting was significantly longer for SPS (49 min). Both ERCs showed radiopacity above the 3.0 mm Al minimum, with higher values for CZS (4.58 mm Al). The solubility remained controlled, with CZS presenting the highest value (3.09%). Both materials exhibited an alkaline pH, peaking at 24 h (CZS: 9.70; SPS: 10.04) and decreasing until 168 h (CZS: 7.80; SPS: 8.31). Sustained ionic release was observed: CZS showed intermediate calcium release (25.96 mg/L at 3 h), whereas SPS displayed lower values (10.95 mg/L at 168 h), without significant difference from WMTA (p > 0.05). Under these conditions, the experimental ERCs demonstrated adequate physicochemical performance comparable with commercial materials. Full article

Superhydrophobic materials have clear potential for mitigating rain/humidity-induced damage to cultural heritage. In the present study, the wetting properties of Paraloid B72 were tailored to achieve superhydrophobicity by incorporating modified calcium carbonate (CaCO₃) nanoparticles (NPs). B72 is a well-established conservation product while CaCO₃ is chemically compatible with calcareous materials commonly found in cultural heritage buildings and objects. Initially, the wettabilities of CaCO₃ NPs, functionalised with caproic (C6), caprylic (C8), lauric (C12), myristic (C14), palmitic (C16), and stearic (C18) acid, were evaluated by measuring water contact angles (CAs) on NP pellets. For NPs with short hydrocarbon chains, CA increased with chain length, from 66.3° for CaCO₃-C6 to 118.0° for CaCO₃-C12 NPs. For NPs with longer chains, CA remained stable and around 118°. Based on these results, CaCO₃-C12 NPs were selected for further investigation and subjected to transmission electron microscopy analysis, which revealed chain-like agglomerates of aggregated nanocrystallites (5–10 nm) forming 40–150 nm polycrystalline NPs. Scanning transmission electron microscopy combined with elemental mapping revealed a homogeneous distribution of Ca, C, and O within the NPs. Next, CaCO₃-C12 NPs were dispersed in B72 solutions and sprayed onto limestone, which was employed as a model calcite-rich substrate. At optimal NP concentration, the resulting composite coating exhibited superhydrophobicity (CA > 150°), while it induced minimal colour alteration to limestone and effective resistance to capillary water absorption. The fluorine-free coating also demonstrated good durability against UV exposure, drop impact, salt attack, freeze–thaw cycles, tape peeling, drop pH variations, and thermal treatment. Full article

Phosphorus is crucial for reconstructing long-term feedback mechanisms between climate, the environment and ecology, as well as for assessing global biogeochemical changes. This study documents two thin yet laterally continuous phosphorite beds from the lower Nenjiang Formation (Late Cretaceous) of the Songliao Basin in NE China and evaluates their mineralogical characteristics and paleoenvironmental significance. The phosphorite beds occur in sharp contact with adjacent black shale and contain well-preserved Ostracoda and conchostracan fossils, providing biological constraints on the depositional conditions. Bulk rock compositions indicate elevated P₂O₅ contents, ranging from approximately 20 to 30 wt%. Mineralogical analyses reveal that the dominant phosphate mineral is carbonate-fluorapatite (CFA), accompanied by minor quartz, hydromica, goethite and pyrrhotite. Integrated fossil, sedimentological, and geochemical evidence suggests that CFA precipitated in a deep, stratified, eutrophic lacustrine environment. Enhanced productivity, biological enrichment and microbial decomposition of organic matter likely promoted phosphorus enrichment in bottom waters, facilitating CFA precipitation at or near the sediment-water interface during deposition and early diagenesis. Variations in physicochemical conditions, including pH and Ca²⁺ concentrations, may have further influenced mineral precipitation and subsequent diagenetic processes. These findings contribute to our understanding of phosphorus precipitation mechanisms in lacustrine basins and provide new constraints on the Late Cretaceous paleoenvironment of the Songliao Basin. Full article

Trioctyl(alkyl)phosphonium chloride ionic liquids ([P_888n][Cl], n = 8, 14, and 16) were synthesized, characterized, and investigated for the extraction of Co, Ni, Mn, Mg, Zn, and Ca from chloride solutions. The three ionic liquids were very effective for the extraction of cobalt (over 95%) from solutions containing 1 g/L of Co(II) and 4 M HCl or NaCl. Equilibrium cobalt extraction was attained in less than 10 min at 25 °C using the most viscous ionic liquid [P₈₈₈₁₆][Cl]. Based on a speciation diagram for cobalt–chloride species and ultraviolet–visible spectrometric analysis of the phases, it was concluded that Co(II) extraction involved the extraction of the neutral species CoCl₂. Only at high chloride concentration, the anionic exchange mechanism involving $\mathrm{C}\mathrm{o}{\mathrm{C}\mathrm{l}}_4^{2-}$ was the most dominant. The stripping of the loaded ionic liquids can be carried out with water, and the stripped ionic liquids can be recycled up to five times maintaining their extraction effectiveness. In all of the conditions tested, the selectivity of [P_888n][Cl] ionic liquids for the extraction of cobalt over nickel was great, with a separation factor over 25,000 for 5M HCl solutions. Furthermore, very good selectivity for Co(II) over Mg(II) and Ca(II) extraction was also obtained. Conversely, Zn(II) can be selectively extracted over Co(II) and Mn(II) using only diluted [P₈₈₈₁₄][Cl]. Full article

Granitic soils in the Highlands support the cultivation of Arabica coffee in northern Thailand; however, their geochemical and radiological properties are inadequately defined. This study examined major oxides, trace elements, natural radionuclides, and extractable phosphorus in granitic-derived coffee soils from the Agricultural Innovation Research, Integration, Demonstration, and Training Center (AIRID) in Chiang Mai. Twenty soil samples were obtained from 10 locations at two depth intervals (0–30 cm and 30–60 cm). Major and trace elements were analyzed via X-ray fluorescence (XRF), natural radionuclides were analyzed through high-purity germanium (HPGe) gamma spectrometry, and extractable phosphorus was determined using the Bray II method. The soils demonstrate remarkably high ⁴⁰K activity concentrations (1.2–1.9 kBq kg⁻¹) and increased K₂O contents (4.9–7.8 wt%), about three to five times more than worldwide soil averages according to Reimann & de Caritat, indicating enrichment from potassium-rich granitic rocks. Major oxide compositions suggest extensive tropical weathering, characterized by elevated SiO₂ (>60 wt%) and Al₂O₃ (>14 wt%), alongside significant depletion of CaO and MgO (<1 wt%). In topsoil, Bray II–extractable phosphorus constitutes 10–25% of total phosphorus and has a robust positive connection with P₂O₅ (R² = 0.95, p < 0.001), signifying surface accumulation and restricted vertical mobility. Multivariate analysis indicates lithogenic grouping of trace elements with negligible vertical redistribution. These findings establish a geochemical and radiological baseline for highland coffee soils in northern Thailand, with implications for soil fertility assessment, soil–plant transfer research, and evaluations of natural radioactive exposure related to coffee production. Full article