Regulation of brain-specific kinases 1 and 2 (BRSK1/2) by Ca2+/calmodulin.

Influence of trace addition of Ca on the mechanical property and corrosion behavior of extruded micro-alloyed Mg0.5Zn0.2Ge alloy

Pleurotus species are nutritionally rich fungi, yet their potential to bioaccumulate environmental fluoride (F⁻) necessitates careful scientific evaluation further. In this study, Pleurotus mushrooms cultivated on F⁻ enriched substrates exhibited significant bioaccumulation of F⁻, indicating their sensitivity to substrate quality and environmental contamination. Supplementation with calcium (Ca) played a crucial physiological role by reducing F⁻ toxicity within the fruiting bodies of mushroom, although its effects were species dependent. Notably, Ca addition mitigated F⁻ stress at the biochemical and cellular level in Pleurotus ostreatus, whereas P. djamor experienced a reduction in growth performance, demonstrating differential tolerance mechanisms. Molecular-level assessment through FTIR-spectroscopy highlighted marked alterations in functional groups associated with proteins, lipids, and carbohydrates under combined F⁻ and Ca exposure, emphasizing stress-induced metabolic shifts. Field-based evaluations further validated laboratory observations, revealing substantial F⁻ accumulation in mushrooms grown using fluoridated-straw and F⁻ rich groundwater, particularly in Set 1N (96.6mg/kg-dw) and Set 4N (46mg/kg-dw). Subcellular fractionation studies confirmed that accumulated fluoride predominantly localized within the cell wall fraction, suggesting a sequestration strategy for detoxification. Bioconcentration factor (BCF) analysis indicated higher accumulation in P. ostreatus relative to P. djamor. However, despite partial mitigation by Ca supplementation and health risk assessments demonstrated that both mushroom species exceeded the non-carcinogenic risk threshold for children when cultivated in traditional way under contaminated conditions. These findings underscore the importance of using controlled, F⁻ free substrates and clean irrigation sources to ensure food safety and promote sustainable mushroom cultivation practices, particularly in fluoride-affected regions such as West Bengal, India.

Mechanical performance and wear characteristics of extruded Mg-Zn-Y alloys with diverse elemental additions in Hank’s solution

Based on compiled mineralogical and geochemical data, we show that burbankite-rich ferrocarbonatite is altered to calcite–bastnäsite–monazite ore at Swartbooisdrift, NW Namibia. The magmatic carbonatite assemblage comprises ankerite, magnetite, pyrochlore, fluorapatite, and locally abundant burbankite. All of these minerals can be enriched in layers that define a magmatic flow banding. Burbankite formation can be restrained to ~ 650 °C. Late-magmatic to hydrothermal alteration proceeds in situ from burbankite to carbocernaite (I to II) ± calcite ± barite ± strontianite, then cordylite-(Ce), monazite-(Ce) and finally ancylite-(Ce). Pyrochlore alters to columbite-(Fe) and fluorapatite to secondary monazite-(Ce). The calcite–bastnäsite–monazite ore forms below ~ 460 °C as veins, lenses and bands confined to the main ferrocarbonatite dikes. Its pinkish color results from minor hematite. Mass-balance calculations indicate fluid-assisted removal of Sr, Na, Mg, Ba and addition of Ca, P, Fe, Mn and LREE with modest volume loss to reach ore grades. C-O stable isotope analyses for the ferrocarbonatite, burbankite and LREE ore show an increasingly heavier δ18O signature linked to the hydrothermal alteration with an interpreted rising crustal influence and decreasing temperatures. Additionally, in-situ trace element analysis further provides arguments for the hydrothermal character of LREE redistribution through fluid-sensitive element ratios (Th/U; Y/Ho; Pb/Th). Our data suggest that formation of the Swartbooisdrift LREE ore results from instability and reaction of early Na-carbonates, apatite, and pyrochlore with progressive fluid evolution (decreasing Na and increasing oxygen fugacity with decreasing T), finally leading to a transformation of burbankite-rich zones of ferrocarbonatite into pink ore along carbonatite-hosted structures. This establishes a coherent magmatic–hydrothermal pathway from primary burbankite to economic LREE mineralization.

The activation of surface-enhanced Raman scattering (SERS) signals is commonly attributed to nanoparticle aggregation, while the contribution of analyte adsorption is often overlooked. Here, we show that silver nanoparticles act as nanoelectrodes, with their electrochemical potential (Fermi level) tuned in situ by atomic ions. This modulation of surface potential dictates the selective adsorption of anionic and cationic analytes, thereby enabling controlled SERS activation. Specifically, the addition of Ca²⁺ to colloidal AgNPs depletes electrons from the metal and promotes the formation of surface Ag⁺, as confirmed by X-ray photoelectron spectroscopy. In our model, Ca²⁺ addition increases the ionic strength of the medium, reducing the Debye radius around the nanoparticles. Under these conditions, ion transport is governed by diffusion rather than migration. Because H⁺ diffuses faster than OH⁻, localized acidification at the nanoparticle surface occurs, which further enhances electron depletion, drives surface Ag⁺ formation, and lowers the Fermi level. This favors adsorption of anionic species such as citrate, thereby activating their SERS signal. Conversely, Cl⁻ adsorption induces partial charge transfer to the nanoparticle, resulting in a Fermi level upshift. This more negative electrochemical potential promotes the adsorption and ultrasensitive SERS detection of cationic analytes such as Nile Blue (10⁻⁸ M). Overall, these findings demonstrate that SERS is switched on when analytes adsorb to the metal surface, where the localized electromagnetic near field is maximized.

To investigate the corrosion behaviours of different refractories (MgO and Al 2 O 3 ) by Al-killed liquid steel after calcium treatment, high-temperature experiments were carried out in laboratory with different Ca additions. The phases and the composition of the reaction layer at the refractory-steel boundary were analysed, and its thickness was measured. It was found that, when the MgO refractory contacted with the liquid steel, a thin MgO-Al 2 O 3 layer was generated without Ca addition. When the Ca content in steel increased to 28 ppm, a dotted (even a continuous) CaO-Al 2 O 3 layer was formed on the edges of the MgO and Al 2 O 3 refractories, with its thickness reaching up to 695 μm. Vaporized Ca gas also caused evident corrosion of refractory, producing CaO as the reaction product. In addition, the microstructure of the refractory influenced the corrosion of the refractory as well, and less porous refractory had weaker corrosion. Due to the corrosion of refractory, the spalling of the refractory grains and the detachment of the CaO-Al 2 O 3 reaction layer both would lead to the formation of large-sized inclusions in steel. Therefore, the addition amount of Ca should be strictly controlled during calcium treatment.

The development of oxygen electrodes for reversible solid oxide cells (RSOCs) is hindered by insufficient catalytic activity, limited stability, and a mismatch in the thermal expansion coefficients (TEC) with electrolytes. Herein, we design and synthesize a novel perovskite oxide, La0.6Ca0.4Fe0.8Ni0.1Co0.1O3-δ (LCFNC), using a multi-element B-site synergistic doping strategy. Systematic investigations reveal that the incorporation of Fe stabilizes the perovskite lattice, while the addition of Ni and Ca effectively suppresses the TEC (to 12.7×10-6 K-1 after GDC compositing), ensuring excellent electrolyte compatibility. Furthermore, the cooperative interplay between Ni, Co, and Fe establishes ternary active centers, significantly increasing the concentration of surface oxygen vacancies. Full-cell measurements demonstrate a peak power density of 1.60 W·cm-2 at 800°C and a high electrolysis current density of 1.82 A·cm-2 at 1.3V. Stability tests, including 100h of constant-current electrolysis at 750°C and 24 reversible operation cycles, highlight exceptional interfacial and structural stability. More importantly, the assembled industrial-sized RSOCs (15×15 cm2) achieve an output power of 64W in fuel cell mode and a maximum current of 105 A in electrolyzer mode at 800°C, demonstrating its potential for practical applications. This work elucidates the mechanistic role of multi-element B-site regulation and provides an effective design principle for oxygen electrode materials that enhance activity, stability, and compatibility simultaneously, thus advancing the practical deployment of high-performance RSOCs.

This study examined the performance of limestone calcined clay cement (LC3) produced with Indonesian clays containing low–medium kaolinite (20–30%) and clinker contents below 50%. Material characterization was carried out using XRF, XRD, and particle size analysis, followed by evaluation of fresh and mechanical properties. LC3 mixtures incorporating local clays exhibited good workability and required less superplasticizer than metakaolin-based controls, indicating favourable fresh behaviour despite reduced clinker content. A notable strength reduction was observed when clinker content dropped below 35%, reflecting insufficient portlandite required for pozzolanic reactions. The addition or substitution of Ca(OH)₂ did not improve strength and hindered calcined clay reactivity due to elevated pH level (12.5–13.5). Microstructural analysis confirmed that mixtures with higher kaolinite and clinker contents produced denser hydration products. The results demonstrated that Indonesian clays are suitable for LC3 development, with promising fresh properties and microstructural behaviour supporting further optimization and future durability studies.

Enhancing the dealloying kinetics and microstructural control of Mg–Ti composites through Ca addition to the Mg melt

With the progressive depletion of petroleum resources and the worsening greenhouse effect, the demand for sustainable materials has become increasingly urgent. In this study, a composite film was fabricated using waste tobacco stems as the raw material by integrating the TEMPO oxidation process with the in situ growth of metal–organic frameworks (MOFs) and subsequent Ca2+ cross-linking. The incorporation of ZIF-8 significantly enhanced the film’s thermal stability, hydrophobicity, and water vapor barrier performance. Compared with pure cellulose nanofiber (CNF), the ZIF-8-loaded composite film exhibited a markedly higher water contact angle (68.2°) and tensile strength (130.54 MPa). The structural characteristics of the films were comprehensively analyzed using FTIR, XRD, and XPS. Moreover, the composite film demonstrated outstanding antibacterial activity, with the addition of Ca2+ facilitating the sustained release of antibacterial agents. The film effectively extended the postharvest storage life of grapes. Owing to its multifunctional properties, the ZIF-8/CNF-Ca composite film shows great potential as a biodegradable alternative to conventional plastic packaging materials.

The influence of solidification cooling rate on the microstructure, particularly Fe-rich particles, in a Mg-0.1Ca (wt%) alloy is studied, as well as the corresponding effect on the corrosion resistance. It is revealed that a slow cooling rate (<5 K s−1) is required for Mg–Ca lean alloys to achieve high corrosion resistance, with corrosion rates <0.2 mm y−1 (in 3.5 wt% NaCl solution). With a low cooling rate, Fe-rich particles with a few hundred nanometers in size are found but largely wrapped by CaMgSi intermetallics at the micrometer scale introduced by Ca addition. Therefore, Fe is sequestered from the matrix, which suppresses micro-galvanic corrosion and cathodic hydrogen evolution kinetics, contributing to the improved corrosion resistance by three orders of magnitude in comparison to that of a high-purity Mg (~20 ppm Fe). However, high cooling rates (like 260 K s−1) result in obviously decreased size of CaMgSi, leaving more Fe-rich particles incompletely wrapped or even fully isolated, which promote cathodic hydrogen-evolution kinetics and intensify micro-galvanic corrosion. Thus, the Mg-0.1Ca alloy shows decreased corrosion resistance when the cooling rate increases. This work demonstrates the significance of Ca micro-alloying and solidification control for developing corrosion-resistant Mg by eliminating the detrimental effect associated with parts-per-million-level Fe impurity.

ABSTRACT Artificial acceleration of Microcystis buoyancy was attempted by manipulating temperature (15-35 °C) to reduce intracellular polysaccharides and increase gas vesicles, as well as varying the amount of Ca2+ (500 and 1,000 mg/L) and tightly bound extracellular polysaccharides (TB-EPS) (200 mg/L) to expand the colony size in preculture. In preculture, changes in temperature affected the floating velocity of Microcystis, and the floating velocity was 4.9 and 6.4 times higher at 35 °C than that at 15 and 25 °C in dark conditions, respectively. Since the content of intracellular polysaccharides at each temperature condition was not largely different (range: 9.9-11.1 pg/cell, p &amp;gt; 0.05), gas vesicle volume would be concerned with the buoyancy, whereas in dark conditions at 35 °C, the addition of Ca2+ (1,000 mg/L) and TB-EPS (200 mg/L) into the medium containing Microcystis enlarged colony size from 280 μm as the mean for the control to 390 μm, which resulted in 1.9 times faster floating velocity. It was expected that Ca2+ could promote colony size expansion of Microcystis by forming cross-linking structures with the negatively charged functional groups originally present, and externally added TB-EPS. These findings provide new insights into strategies for more efficient removal of Microcystis in lakes.

<br><i>Bruguiera gymnorrhiza</i> and <i>Acanthus ilicifolius</i> are key mangrove species, but their populations have declined recently due tohuman activities. Topromote their restoration, this study optimised seed germination and seedling cultivation using the plant factory method. The parameters, such asillumination, salinity, temperature and nutrient conditions, were examined. Our results showed that suitable illumination, salinity and temperature promoted seed germination ofboth species. Nutrient addition promoted the germination of<i>B</i>. <i>gymnorrhiza</i> but had little effect on<i>A</i>. <i>ilicifolius</i>. Both species ofseedlings grew best inshort illumination duration and moderate illumination intensity. Although both species can tolerate high salinity, low salinity (0–10‰ for <i>B</i>. <i>gymnorrhiza</i> and 0–5‰ for <i>A</i>. <i>ilicifolius</i>) promoted seedlings’ growth. High temperature (28–32C) accelerated the growth ofboth species ofseedlings. Nutrient addition enhanced the growth ofboth species’ seedlings, especially the addition ofCa²⁺/Mg²⁺ and trace elements strongly promoted the growth of<i>B</i>. <i>gymnorrhiza</i> seedlings. We obtained optimal conditions for seed germination and seedling growth of both species in the plant factory, demonstrating that environmental control significantly enhanced their germination and growth rates. Our findings provide valuable insights into the efficiency of mangrove restoration and the sustainable development of mangrove ecosystems.

Grain refinement and enhanced mechanical properties of rolled and annealed Mg–3Al alloy through trace Ca addition

The direct regeneration of spent lithium-ion batteries has attracted considerable attention due to its potential to maximize economic benefits while minimizing environmental impacts. However, fluorine-containing contaminants severely interfere with the regeneration process through chemical interactions, often resulting in the cathode fluorination. Moreover, constrained by the technical limitations inherent in the original synthesis processes of waste electrodes, the cycling stability of regenerated cathode materials struggles to meet the current technical standards. Herein, we elucidate the underlying mechanisms of F-induced degradation in spent cathode materials and develop a flash Joule heating (FJH) technique with a Ca(OH)2 medium to achieve the coupling effect of fluorination inhibition and lattice stabilization in a single processing step. The addition of Ca(OH)2 can effectively capture the secondary HF, mitigating its corrosion of the cathodes to form a metal fluoride. Furthermore, the high temperature during FJH treatment facilitates in situ Ca doping into the LiCoO2 lattice, enhancing its electronic and ionic conductivity. Following hydrothermal relithiation and a brief sintering regeneration process, the regenerated Ca-doped LiCoO2 demonstrates a high capacity of 150.2 mAh/g (0.1 C) and enhanced cycling stability from 64.3 to 91.2% compared to that without Ca doping. This work provides a mechanistically guided and industrially adaptable strategy for the efficient regeneration of fluorinated cathodes, advancing the practical implementation of sustainable battery recycling.

Bone tissue engineering necessitates the utilization of scaffolds that amalgamate biocompatibility, mechanical robustness, and antimicrobial properties to effectively address the challenges of regeneration and infection control. Natural polymers, such as chitosan, inherently offer bioactivity; however, they require reinforcement to achieve optimal functionality. To formulate an eco-friendly calcium/exfoliated bentonite/chitosan (Ca/EXF-BE/CS) nanocomposite scaffold with enhanced mechanical strength and antimicrobial efficacy for applications in bone tissue engineering. Calcium oxide was derived from waste eggshells through the process of calcination at 600 °C. The Egyptian bentonite was subjected to purification and exfoliation via CTAB-assisted ultrasonication. Ca/EXF-BE nanocomposites were synthesized employing green tea-mediated precipitation, followed by the encapsulation with chitosan through ionic gelation utilizing tripolyphosphate as a crosslinking agent. Characterization was conducted using XRD, FE-SEM, FTIR, BET analysis, and mechanical testing. The antimicrobial efficacy was evaluated against E. coli, S. aureus, and C. albicans using well diffusion and MIC/MBC assays. The Ca/EXF-BE/CS exhibited the highest surface area value of 134.6 m2/g, coupled with an average pore width of 44.5 Å. The mechanical properties of EXF-BE were significantly enhanced with the addition of Ca and CS, as evidenced by the ultimate tensile strength (σuts) values of 15.38 ± 0.40MPa, 16.19 ± 0.38 MPa, and 17.84 ± 0.42 MPa; toughness measurements of 1.435 ± 0.23 MJ/m3, 1.713 ± 0.25 MJ/m3, and 2.067 ± 0.31 MJ/m3; and strain at breakdown percentages of approximately 28.5 ± 0.31%, 28.69 ± 0.3%, and 30.1 ± 0.33% for EXF-BE, Ca/EXF-BE, and Ca/EXF-BE/CS, respectively. The antimicrobial properties, evaluated through the well diffusion method, revealed inhibition zones measuring 27.13, 21.25, and 23 mm against E. coli, S. aureus, and Candida albicans, respectively, at 1000 µg/mL of Ca/EXF-BE, thereby demonstrating promising multifunctional capabilities. The Ca/BE/CS nanocomposite, produced via sustainable synthesis from eggshell waste, demonstrates enhanced strength, toughness, porosity, and antimicrobial activity. Its multifunctional performance makes it a promising scaffold for load-bearing bone tissue engineering and infection control in orthopedic applications.

Ultra-High-Performance Concrete (UHPC) is being increasingly utilized in major engineering projects due to its excellent mechanical properties, strong durability, and superior overall performance. Nevertheless, the widespread use of premium cementitious materials leads to high expenses and a substantial environmental impact. In this work, crushed recycled paste was calcined at 600 °C for two hours to produce calcined recycled fine powder (RFP) with varying hydration reactivity. UHPC was produced using the RFP in place of some of the cement. Chemical activation was accomplished by adding a composite activator system made up of Ca(OH)2, Na2SO4, Na2SiO3·9H2O, and K2SO4 in order to further improve the performance of UHPC. Particle size, viscosity, fluidity, mechanical properties, and hydration products were analyzed to establish the best activator type and dosage, as well as the ideal activation procedure for recycled fine powder. By mass replacement of cementitious materials, when 15.0% of the calcined recycled fine powder was added, the compressive strength of UHPC reached 149.1 MPa, a 23.2% increase over reference UHPC without calcined recycled fine powder. The results show that the calcined recycled fine powder ground for 60 min exhibits the highest activity. More hydrated products were formed in UHPC as a result of the addition of Ca(OH)2. The compressive strength peaked at 162.2 MPa at an incorporation rate of 1.5%, which is 8.8% higher than UHPC without an activator.

ABSTRACT The Lugiin Gol deposit is one of four REE deposits (Khalzan Burged, Mushigai Khudag, and Khotor) in Mongolia. It consists of a nepheline syenite stock, equivalent dike rocks, and more than 400 carbonatite veins within an area of approximately 13 km 2 . This study focuses mainly on the western part of the Lugiin Gol deposit. The western Lugiin Gol deposit consists of many carbonatites that fill NE‐trending fractures in sedimentary rock. The minerals in the carbonatites include calcite, dolomite, strontianite, kutnohorite, ankerite, fluorite, synchysite‐(Ce), bastnaesite‐(Ce), parisite‐(Ce), synchysite‐bastnaesite intergrowths, rutile, apatite, goyazite, quartz, K‐feldspar, muscovite, chlorite, Al‐Si mineral, Na‐Si mineral, pyrite, sphalerite, chalcopyrite, galena, Fe hydroxide, and graphite. Synchysite‐(Ce), bastnaesite‐(Ce), parisite‐(Ce), and synchysite‐bastnaesite intergrowths are REE fluorocarbonates. Synchysite‐(Ce), the most abundant REE fluorocarbonate, occurs as disseminated euhedral crystals in carbonates, Fe hydroxide, and K‐feldspar. It is LREE‐dominant, with La/Ce ratios ranging from 0.47 to 0.84, and its LREE abundance decreases in the order Ce &gt; La &gt; Nd &gt; Gd &gt; Sm &gt; Eu. Bastnasesite‐(Ce), the second most abundant REE fluorocarbonate, occurs as granular crystals closely intergrown with synchysite‐(Ce). It is also LREE‐dominant, with La/Ce ratios ranging from 0.68 to 0.91, and LREE abundances in the order Ce &gt; La &gt; Nd &gt; Gd &gt; Eu &gt; Sm. Parisite‐(Ce), the third most abundant REE fluorocarbonate, occurs as anhedral or granular crystals that are closely intergrown with or replaced by synchysite‐(Ce). It is LREE‐dominant, with La/Ce ratios ranging from 0.38 to 0.61, and LREE abundances in the order Ce &gt; La &gt; Nd &gt; Gd &gt; Sm &gt; Eu. The synchysite‐bastnaesite intergrowths occur as granular crystals and are LREE‐dominant, with La/Ce ratios ranging from 0.81 to 0.97, and LREE abundances in the order Ce &gt; La &gt; Nd &gt; Gd &gt; Eu. The grain size and intergrowth textures of the REE minerals govern the grinding fineness required to achieve sufficient mineral liberation. REE mineral grains in this deposit range from fine (&lt; 150 μm) to moderately coarse (&lt; 400 μm), but they commonly occur locked with gangue minerals. This indicates that the ore must be ground sufficiently fine to break the intergrowths and liberate the REE minerals. Based on the observed REE mineral textures, REE mineralization was formed by the addition of Ca and a decrease in temperature in ore‐bearing fluids (from approximately 100°C to over 400°C) at relatively low pressures. Therefore, information on the occurrence and chemical composition of REE minerals can be used as basic data for understanding REE minerals genesis and improving their recovery rates.

This research aimed to investigate the modulation of broiler-chickens gut microbiota by dietary particle size (PS), exogenous phytase, and calcium (Ca) concentration. Eight experimental diets varied in PS (fine 222 µm (PF) and coarse 309 µm (PC)), Ca concentration (4.9 and 7.2 g/kg), and exogenous phytase (0 and 1000 FTU/kg). A total of 560 Ross 308 broiler chickens were allocated to 56 metabolism units at 7 days of age and randomly assigned to each diet (7 replicates per treatment). On days 22 and 23, the birds were slaughtered, and the digesta from the gizzard, ileum, and ceca were sampled and pooled on a metabolism unit basis. DNA extraction was followed by 16S rRNA gene amplicon sequencing. Thirteen amplicon sequence variants (ASV) were present across the gizzard, ileum, and ceca, most of which were assigned to Limosilactobacillus and represented a substantial share of the total relative abundance in each section, 86 % in the gizzard, 88 % in the ileum, and 30 % in the ceca. Six of these L. reuteri ASVs were significantly enriched by coarse particle feeding, suggesting strain-specific adaptation to enhanced phosphorus availability. In the ileum, Candidatus arthromitus (p < 0.001) and Rombustia (p < 0.05) showed a significant increase in relative abundance in PC compared to PF. Phytase supplementation reduced the relative abundance of Lactobacillus and Streptococcus (p < 0.05), while higher Ca concentration decreased that of C. arthromitus (p < 0.05). In the ceca, increases in the relative abundance of Anaerostipes (p < 0.05) and Clostridia vadin BB60 were found for PC diets compared to PF (p < 0.001). The addition of phytase and Ca also significantly affected several genera, albeit the variations were less than 1 %. Dietary PS, exogenous phytase, and Ca concentration modulated the gut microbiota, specifically influencing the abundance of key microorganisms like Candidatus arthromitus, Anaerostipes, and Clostridia vadin BB60, involved in phosphorus metabolism and overall broiler chickens' health.