Concomitant urea stabilization and phosphorus recovery from source-separated fresh urine in magnesium anode-based peroxide-producing electrochemical cells.

In this study, we investigated the recovery of nitrogen (N) and phosphorus (P) from fresh source-separated urine with a novel electrochemical cell equipped with a magnesium (Mg) anode and carbon-based gas-diffusion cathode. Recovery of P, which exists primarily as phosphate (PO43-) in urine, was achieved through pH-driven precipitation. Maximizing N recovery requires simultaneous approaches to address urea and ammonia (NH3). NH3 recovery was possible through precipitation in struvite with soluble Mg supplied by the anode. Urea was stabilized with electrochemically synthesized hydrogen peroxide (H2O2) from the cathode. H2O2 concentrations and resulting urine pH were directly proportional to the applied current density. Concomitant NH3 and PO43- precipitation as struvite and urea stabilization via H2O2 electrosynthesis was possible at lower current densities, resulting in urine pH under 9.2. Higher current densities resulted in urine pH over 9.2, yielding higher H2O2 concentrations and more consistent stabilization of urea at the expense of NH3 recovery as struvite; PO43- precipitation still occurred but in the form of calcium phosphate and magnesium phosphate solids.

Kidney stone growth through the lens of Raman mapping.

Bulk composition of kidney stones, often analyzed with infrared spectroscopy, plays an essential role in determining the course of treatment for kidney stone disease. Though bulk analysis of kidney stones can hint at the general causes of stone formation, it is necessary to understand kidney stone microstructure to further advance potential treatments that rely on in vivo dissolution of stones rather than surgery. The utility of Raman microscopy is demonstrated for the purpose of studying kidney stone microstructure with chemical maps at ≤ 1 µm scales collected for calcium oxalate, calcium phosphate, uric acid, and struvite stones. Observed microstructures are discussed with respect to kidney stone growth and dissolution with emphasis placed on < 5 µm features that would be difficult to identify using alternative techniques including micro computed tomography. These features include thin concentric rings of calcium oxalate monohydrate within uric acid stones and increased frequency of calcium oxalate crystals within regions of elongated crystal growth in a brushite stone. We relate these observations to potential concerns of clinical significance including dissolution of uric acid by raising urine pH and the higher rates of brushite stone recurrence compared to other non-infectious kidney stones.

Enhanced efficiencies on purifying acid mine drainage in constructed wetlands based on synergistic adsorption of attapulgite-soda residue composites and microbial sulfate reduction.

Constructed wetlands (CWs) are a promising approach for treating acid mine drainage (AMD). However, the extreme acidity and high loads of heavy metals in AMD can easily lead to the collapse of CWs without proper pre-treatment. Therefore, it is considered essential to maintain efficient and stable performance for AMD treatment in CWs. In this study, pre-prepared attapulgite-soda residue (ASR) composites were used to improve the substrate of CWs. Compared with CWs filled with gravel (CWs-G), the removal efficiencies of sulfate and Fe, Mn, Cu, Zn Cd and Pb in CWs filled with ASR composites (CWs-ASR) were increased by 30% and 10-70%, respectively. These metals were mainly retained in the substrate in stable forms, such as carbonate-, Fe/Mn (oxide)hydroxide-, and sulfide-bound forms. Additionally, higher levels of photosynthetic pigments and antioxidant enzyme activities in plants, along with a richer microbial community, were observed in CWs-ASR than in CWs-G. The application of ASR composites alleviated the adverse effects of AMD stresses on wetland plants and microorganisms. In return, the increased bacteria abundance, particularly SRB genera (e.g., Thermodesulfovibrionia and Desulfobacca), promoted the formation of metal sulfides, enabling the saturated ASR adsorbed with metals to regenerate and continuously capture heavy metals. The synergistic adsorption of ASR composites and microbial sulfate reduction maintained the stable and efficient operation of CWs. This study contributes to the resource utilization of industrial alkaline by-products and promotes the breakthrough of new techniques for low-cost and passive treatment systems such as CWs.

Development of cell-laden photopolymerized constructs with bioactive amorphous calcium magnesium phosphate for bone tissue regeneration via 3D bioprinting.

The synthesis of ideal bioceramics to guide the fate of cells and subsequent bone regeneration within the chemical, biological, and physical microenvironment is a challenging long-term task. This study developed amorphous calcium magnesium phosphate (ACMP) bioceramics via a simple co-precipitation method. The role of Mg2+ in the formation of ACMP is investigated using physicochemical and biological characterization at different Ca/Mg molar ratio of the initial reaction solution. Additionally, ACMP bioceramics show superior cytocompatibility and improved osteogenic differentiation of co-cultured MC3T3-E1 cells. Regulation of the microenvironment with Mg2+ can promote early-stage bone regeneration. For this, bioprinting technology is employed to prepare ACMP-modified 3D porous structures. Our hypothesis is that the incorporation of ACMP into methacrylated gelatin (GelMA) bioink can trigger the osteogenic differentiation of encapsulated preosteoblast and stimulate bone regeneration. The cell-laden ACMP composite structures display stable printability and superior cell viability and cell proliferation. Also, constructs loading the appropriate amount of ACMP bioceramic showed significant osteogenic differentiation activity compared to the pure GelMA. We demonstrate that the dissolved Mg2+ cation microenvironment in ACMP-modified composite constructs plays an effective biochemical role, and can regulate cell fate. Our results predict that GelMA/ACMP bioink has significant potential in patient-specific bone tissue regeneration.

Understanding the role of zinc ions on struvite nucleation and growth in the context of infection urinary stones.

Taking into account that in recent decades there has been an increase in the incidence of urinary stones, especially in highly developed countries, from a wide range of potentially harmful substances commonly available in such countries, we chose zinc for the research presented in this article, which is classified by some sources as a heavy metal. In this article, we present the results of research on the influence of Zn2+ ion on the nucleation and growth of struvite crystals-the main component of infection urinary stones. The tests were carried out in an artificial urine environment with and without the presence of Proteus mirabilis bacteria. In the latter case, the activity of bacterial urease was simulated chemically, by systematic addition of an aqueous ammonia solution. The obtained results indicate that Zn2+ ions compete with Mg2+ ions, which leads to the gradual replacement of Mg2+ ions in the struvite crystal lattice with Zn2+ ions to some extent. This means co-precipitation of Mg-struvite (MgNH4PO4·6H2O) and Znx-struvite (Mg1-xZnxNH4PO4·6H2O). Speciation analysis of chemical complexes showed that Znx-struvite precipitates at slightly lower pH values than Mg-struvite. This means that Zn2+ ions shift the nucleation point of crystalline solids towards a lower pH. Additionally, the conducted research shows that Zn2+ ions, in the range of tested concentrations, do not have a toxic effect on bacteria; on the contrary, it has a positive effect on cellular metabolism, enabling bacteria to develop better. It means that Zn2+ ions in artificial urine, in vitro, slightly increase the risk of developing infection urinary stones.

Nucleic Acid Plate Culture: Label-Free and Naked-Eye-Based Digital Loop-Mediated Isothermal Amplification in Hydrogel with Machine Learning.

Digital nucleic acid amplification enables the absolute quantification of single molecules. However, due to the ultrasmall reaction volume in the digital system (i.e., short light path), most digital systems are limited to fluorescence signals, while label-free and naked-eye readout remain challenging. In this work, we report a digital nucleic acid plate culture method for label-free, ultrasimple, and naked-eye nucleic acid analysis. As simple as the bacteria culture, the nanoconfined digital loop-mediated isothermal amplification was performed by using polyacrylamide (PAM) hydrogel as the amplification matrix. The nanoconfinement of PAM hydrogel with an ionic polymer chain can remarkably accelerate the amplification of target nucleic acids and the growth of inorganic byproducts, namely, magnesium pyrophosphate particles (MPPs). Compared to that in aqueous solutions, MPPs trapped in the hydrogel with enhanced light scattering characteristics are clearly visible to the naked eye, forming white "colony" spots that can be simply counted in a label-free and instrument-free manner. The MPPs can also be photographed by a smartphone and automatically counted by a machine-learning algorithm to realize the absolute quantification of antibiotic-resistant pathogens in diverse real samples.

An innovative Fuller's earth-based film-forming formulation for skin decontamination, through removal and entrapment of an organophosphorus compound, paraoxon-ethyl.

Organophosphorus compounds (OPs), such as VX, pose a significant threat due to their neurotoxic and hazardous properties. Skin decontamination is essential to avoid irreversible effects. Fuller's earth (FE), a phyllosilicate conventionally employed in powder form, has demonstrated decontamination capacity against OPs. The aim of this study was to develop a formulation that forms a film on the skin, with a significant OP removal capacity (>95 %) coupled with sequestration capabilities, favorable drying time and mechanical properties to allow for easy application and removal, particularly in emergency context. Various formulations were prepared using different concentrations of polyvinyl alcohol (PVA), FE and surfactants. Their removal and sequestration capacity was tested using paraoxon-ethyl (POX), a chemical that simulates the behavior of VX. Formulations with removal capacity levels surpassing 95 % were mechanically characterized and cell viability assays were performed on Normal Human Dermal Fibroblast (NHDF). The four most promising formulations were used to assess decontamination efficacy on pig ear skin explants. These formulations showed decontamination levels ranging from 84.4 ± 4.7 % to 96.5 ± 1.3 %, which is equivalent to current decontamination methods. These results suggest that this technology could be a novel and effective tool for skin decontamination following exposure to OPs.

Room-temperature fabrication of fluorinated covalent organic polymer @ Attapulgite composite for in-syringe membrane solid-phase extraction and analysis of domoic acid in aquatic products.

A novel fluorinated covalent organic polymer @ attapulgite composite (F-COP@ATP) was prepared at room temperature for in-syringe membrane solid-phase extraction (SM-SPE) of domoic acid (DA) in aquatic products. Natural ore ATP has the advantages of low cost, good mechanical strength and abundant hydroxyl group on its surface, and in-situ modified F-COP layer can provide abundant adsorption sites. F-COP@ATP combining the advantages of F-COP and ATP, becomes an ideal adsorbent for DA extracting. Moreover, a high-throughput sample preparation strategy was carried out by using the F-COP@ATP membrane as syringe filter and assembling syringes with a ten-channel injection pump. In addition, the experimental factors were optimized, such as pH of extract, amount of adsorbent, velocity of extraction and desorption, type and volume of desorption solvent. The DA analytical method was established by SM-SPE-HPLC/tandem mass spectrometry. The method had a wide linear range with low limit of detection (0.344 ng/kg) and low limit of quantification (1.14 ng/kg). F-COP@ATP membrane can be reused more than five times. The method realized the analysis of DA in scallop and razor clam samples, which shows its application prospect in practical analysis. This study provided an efficient, low-energy and mild idea for preparing other reusable natural mineral ATP-based composite materials for separation and enrichment, which reduces the experimental cost and is closer to environmental protection and green chemistry to a certain extent.

The hemostatic performance and mechanism of palygorskite with structural regulate by oxalic acid gradient leaching.

Palygorskite (Pal) is a naturally available one-dimensional clay mineral, featuring rod-shaped morphology, nanoporous structure, permanent negative charges as well as abundant surface hydroxyl groups, exhibiting promising potential as a natural hemostatic material. In this study, the hemostatic performance and mechanisms of Pal were systematically investigated based on the structural regulate induced by oxalic acid (OA) gradient leaching from perspectives of structure, surface attributes and ion release.In vitroandin vivohemostasis evaluation showed that Pal with OA leaching for 1 h exhibited a superior blood procoagulant effect compared with the raw Pal as well as the others leached for prolonging time. This phenomenon might be ascribed to the synergistic effect of the intact nanorod-like morphology, the increase in the surface negative charge, the release of metal ions (Fe3+and Mg2+), and the improved blood affinity, which promoted the intrinsic coagulation pathway, the fibrinogenesis and the adhesion of blood cells, thereby accelerating the formation of robust blood clots. This work is expected to provide experimental and theoretical basis for the construction of hemostatic biomaterials based on clay minerals.

Construction of Magnesium Phosphate Chemical Conversion Coatings with Different Microstructures on Titanium to Enhance Osteogenesis and Angiogenesis.

Titanium (Ti) and its alloys are widely used as hard tissue substitutes in dentistry and orthopedics, but their low bioactivity leads to undesirable osseointegration defects in the early osteogenic phase. Surface modification is an important approach to overcome these problems. In the present study, novel magnesium phosphate (MgP) coatings with controllable structures were fabricated on the surface of Ti using the phosphate chemical conversion (PCC) method. The effects of the microstructure on the physicochemical and biological properties of the coatings on Ti were researched. The results indicated that accelerators in PCC solution were important factors affecting the microstructure and properties of the MgP coatings. In addition, the coated Ti exhibited excellent hydrophilicity, high bonding strength, and good corrosion resistance. Moreover, the biological results showed that the MgP coatings could improve the spread, proliferation, and osteogenic differentiation of mouse osteoblast cells (MC3T3-E1) and vascular differentiation of human umbilical vein endothelial cells (HUVECs), indicating that the coated Ti samples had a great effect on promoting osteogenesis and angiogenesis. Overall, this study provided a new research idea for the surface modification of conventional Ti to enhance osteogenesis and angiogenesis in different bone types for potential biomedical applications.

Surface functionalization of calcium magnesium phosphate cements with alginate sodium for enhanced bone regeneration via TRPM7/PI3K/Akt signaling pathway.

Although calcium­magnesium phosphate cements (CMPCs) have been widely applied to treating critical-size bone defects, their repair efficiency is unsatisfactory owing to their weak surface bioactivity and uncontrolled ion release. In this study, we lyophilized alginate sodium (AS) as a coating onto HAp/K-struvite (H@KSv) to develop AS/HAp/K-struvite (AH@KSv), which promotes bone regeneration. The compressive strength and hydrophilicity of AH@KSv significantly improved, leading to enhanced cell adhesion in vitro. Importantly, the SA coating enables continuous ions release of Mg2+ and Ca2+, finally leading to enhanced osteogenesis in vitro/vivo and different patterns of new bone ingrowth in vivo. Furthermore, these composites increased the expression levels of biomarkers of the TRPM7/PI3K/Akt signaling pathway via an equilibrium effect of Mg2+ to Ca2+. In conclusion, our study provides novel insights into the mechanisms of Mg-based biomaterials for bone regeneration.

Improving feed intake and rumen fermentation in lambs using mixed-dimensional attapulgite clay to adsorb naturally occurring mycotoxins.

This experiment was conducted to evaluate the effects of including a mixed-dimensional attapulgite clay (MDA) into a naturally moldly diet for Hu lambs. Fifty male Hu lambs with similar initial body weight (28.24 ±â€…1.80 kg) were randomly allocated into five dietary treatments: a basal diet containing naturally occurring mycotoxins with 0, 0.5, 1.0, and 2.0 kg/t MDA, and basal diet with a commercial mycotoxin adsorbent Solis with montmorillonite as the major component at 1 kg/t. Both MDA and Solis increased average daily gain (ADG) and dry matter intake (DMI; P ≤ 0.004), and there was no difference in growth performance between MDA and Solis (P ≥ 0.26). The final body weight, DMI, and ADG were linearly increased with increasing MDA supplementation (P < 0.01). Lambs treated with both MDA and Solis demonstrated greater apparent digestibility of dry matter (DM), organic matter (OM), and energy compared with the control group (P ≤ 0.03), and there were no differences in nutrient digestibilities between MDA and Solis (P ≥ 0.38). Digestibility of CP was linearly increased with the increasing MDA supplementation (P = 0.01). Neither MDA nor Solis affected rumen total volatile fatty acid (TVFA) concentration (P ≥ 0.39), but decreased the acetate-to-propionate ratio and molar proportion of n-butyrate (P ≤ 0.01), and MDA also increased the concentration of ammonia (P = 0.003). Besides, increasing MDA supplementation linearly reduced the acetate-to-propionate ratio and molar proportion of n-butyrate (P = 0.01), but linearly and quadratically increased the concentration of ammonia (P ≥ 0.003). These results showed that the incorporation of MDA into a naturally moldy diet of Hu lambs yielded comparable results to the Solis product, with higher growth performance and nutrient digestibility but lower acetate-to-propionate ratio observed. In conclusion, including ≥ 1 kg/t of MDA in high mycotoxin risk diets for growing lambs improves feed intake and rumen fermentation.

The issue of mycotoxin-contaminated animal feed has consistently presented a significant challenge in relation to animal health and production. The mixed-dimensional attapulgite clay (MDA) has been proven effective in binding polar mycotoxins such as aflatoxin, while also effectively adsorbing hydrophobic or weakly polar mycotoxins such as zearalenone (ZEN) and ochratoxin. Therefore, this study was undertaken to assess the impact of MDA inclusion in mycotoxin-contaminated diets on performance and rumen fermentation variables in lambs. The results indicated that MDA not only significantly improved the growth performance and nutrient digestibility of Hu lambs but also enhanced the molar proportion of propionate and ammonia concentration, and reduced the acetate to propionate ratio and the molar proportion of n-butyrate.

Medical waste incineration fly ash-based magnesium potassium phosphate cement: Calcium-reinforced chlorine solidification/stabilization mechanism and optimized carbon reduction process strategy.

The traditional solidification/stabilization (S/S) technology, Ordinary Portland Cement (OPC), has been widely criticized due to its poor resistance to chloride and significant carbon emissions. Herein, a S/S strategy based on magnesium potassium phosphate cement (MKPC) was developed for the medical waste incineration fly ash (MFA) disposal, which harmonized the chlorine stabilization rate and potential carbon emissions. The in-situ XRD results indicated that the Cl- was efficiently immobilized in the MKPC system with coexisting Ca2+ by the formation of stable Ca5(PO4)3Cl through direct precipitation or intermediate transformation (the Cl- immobilization rate was up to 77.29%). Additionally, the MFA-based MKPC also demonstrated a compressive strength of up to 39.6 MPa, along with an immobilization rate exceeding 90% for heavy metals. Notably, despite the deterioration of the aforementioned S/S performances with increasing MFA incorporation, the potential carbon emissions associated with the entire S/S process were significantly reduced. According to the Life Cycle Assessment, the potential carbon emissions decreased to 8.35 × 102 kg CO2-eq when the MFA reached the blending equilibrium point (17.68 wt.%), while the Cl- immobilization rate still remained above 65%, achieving an acceptable equilibrium. This work proposes a low-carbon preparation strategy for MKPC that realizes chlorine stabilization, which is instructive for the design of S/S materials.

Ca-Mg modified attapulgite for phosphate removal and its potential as phosphate-based fertilizer.

The urgent concerns of controlling water body eutrophication and the alleviating phosphorus shortage have led to an urgent need for action. The removal of phosphate from polluted waters and its reuse are essential for the prevention of eutrophication and for the sustainable utilization of phosphate resources. In this study, modified attapulgite with different Ca:Mg molar ratios was synthesized to facilitate the recovery of phosphate, with subsequent use of soil fertilizer. Ca-Mg modified attapulgite with the optimal ratio (ACM-5:3) exhibited an exceptional adsorption quality, achieving a maximum adsorption capacity of 63.2 mg/g. The pseudo-second-order model and Langmuir model could well describe the adsorption kinetics and isotherms, respectively. The adsorption mechanism analyses suggested that the interaction between ACM-5:3 and phosphate depended mainly on ion exchange and electrostatic attraction. Moreover, phosphate-laden-ACM-5:3 demonstrated a significant potential as a phosphorus-releasing fertilizer. It could promote corn growth by ensuring a continuous supply of phosphorus and minimizing phosphorus runoff losses. The above results suggested that ACM-5:3 was a potential adsorbent for efficient phosphate removal and recovery.

Highly efficient and selective removal of anionic dyes from aqueous solutions using polyacrylamide/peach gum polysaccharide/attapulgite composite hydrogels with positively charged hybrid network.

To avoid the weakness (lower adsorption rate and selectivity) of peach gum polysaccharide (PGP) and improve the adsorption performance of polyacrylamide (PAAm) hydrogel (lower adsorption capacity), in the present work, the PGP was chemically tailored to afford ammoniated PGP (APGP) and quaternized PGP (QPGP), and attapulgite (ATP) was bi-functionalized with cation groups and carbon­carbon double bond. Then, PAAm/APGP and PAAm/QPGP/ATP hydrogels were synthesized via redox polymerization. The synthesis procedure and properties of hydrogels were traced by FTIR, SEM, XPS, TGA, TEM, and BET methods, and the dye adsorption performance of the hydrogels was evaluated using the new coccine (NC) and tartrazine (TTZ) aqueous solutions as the model anionic dyes. Effects of initial dye concentration, pH, and ionic strength on the adsorption were investigated. Compared with PAAm/APGP hydrogel, PAAm/APGP/ATP hydrogel exhibits higher adsorption rate, superior adsorption capacity, stability, and selectivity towards anionic dye. The adsorption process of PAAm/QPGP/ATP hydrogel reached equilibrium in about 20 min and followed the pseudo-second-order kinetic model and Langmuir isotherm. The adsorption capacities towards NC and TTZ of PAAm/QPGP/ATP hydrogel were calculated as 873.235 and 731.432 mg/g. This hydrogel adsorbent originating from PAAm, PGP, and ATP shows great promise for application in practical water treatment.

Development of natural attapulgite derived ferromanganese spinel oxides as heterogeneous catalysts for persulfate activation of tetracycline degradation.

Ferromanganese spinel oxides (MnFe2O4, MFO) have been proven effective in activating persulfate for pollutants removal. However, their inherent high surface energy often leads to agglomeration, diminishing active sites and consequently restricting catalytic performance. In this study, using Al-MCM-41 (MCM) mesoporous molecular sieves derived from natural attapulgite as a support, the MFO/MCM composite was synthesized through dispersing MnFe2O4 nanoparticles on MCM carrier by a simple hydrothermal method, which can effectively activate persulfate (PS) to degrade Tetracycline (TC). The addition of Al-MCM-41 can effectively improve the specific surface area and adsorption performance of MnFe2O4, but also reduce the leaching amount of metal ions. The MFO/MCM composite exhibited superior catalytic reactivity towards PS and 84.3% removal efficiency and 64.7% mineralization efficiency of TC (20 mg/L) was achieved in 90 min under optimized conditions of 0.05 mg/L catalyst dosage, 5 mM PS concentration, room temperature and no adjustment of initial pH. The effects of various stoichiometric MFO/MCM ratio, catalyst dosage, PS concentration, initial pH value and co-existing ions on the catalytic performance were investigated in detail. Moreover, the possible reaction mechanism in MFO-MCM/PS system was proposed based on the results of quenching tests, electron paramagnetic resonance (EPR) and XPS analyses. Finally, major degradation intermediates of TC were detected by liquid chromatography mass spectrometry technologies (LC-MS) and four possible degradation pathways were proposed. This study enhances the design approach for developing highly efficient, environmentally friendly and low-cost catalysts for the advanced treatment process of antibiotic wastewater.

3D-Printed Magnesium Peroxide-Incorporated Scaffolds with Sustained Oxygen Release and Enhanced Photothermal Performance for Osteosarcoma Multimodal Treatments.

The hypoxic microenvironment in osteosarcoma inevitably compromises the antitumor effect and local bone defect repair, suggesting an urgent need for sustained oxygenation in the tumor. The currently reported oxygen-releasing materials have short oxygen-releasing cycles, harmful products, and limited antitumor effects simply by improving hypoxia. Therefore, the PCL/nHA/MgO2/PDA-integrated oxygen-releasing scaffold with a good photothermal therapy effect was innovatively constructed in this work to achieve tumor cell killing and bone regeneration functions simultaneously. The material distributes MgO2 powder evenly on the scaffold material through 3D printing technology and achieves the effect of continuous oxygen release (more than 3 weeks) through its slow reaction with water. The in vitro and in vivo results also indicate that the scaffold has good biocompatibility and sustained-release oxygen properties, which can effectively induce the proliferation and osteogenic differentiation of bone mesenchymal stem cells, achieving excellent bone defect repair. At the same time, in vitro cell experiments and subcutaneous tumorigenesis experiments also confirmed that local oxygen supply can promote osteosarcoma cell apoptosis, inhibit proliferation, and reduce the expression of heat shock protein 60, thereby enhancing the photothermal therapy effect of polydopamine and efficiently eliminating osteosarcoma. Taken together, this integrated functional scaffold provides a unique and efficient approach for antitumor and tumor-based bone defect repair for osteosarcoma treatment.

Acid modified attapulgite loaded with bacillomycin D for mold inhibition and mycotoxin removal.

Molds and mycotoxins pose severe threats to health. Bacillomycin D (BD) can effectively inhibit mold growth. Attapulgite (ATP) can provide a good carrier for antimicrobial agents. Natural ATP was acid-modified to obtain H-ATP. It was used to load BD to obtain a novel composite material (H-ATP-BD). The results showed H-ATP had better adsorption performance than ATP. BD was adsorbed up to 93.13 % by adding 30 mg H-ATP and stirring at 40 ℃ for 120 min. Fourier transform infrared spectra (FTIR), size and zeta potential, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results confirmed successful loading of BD onto H-ATP. The composite showed good inhibition of Aspergillus and adding 0.6 % H-ATP-BD composite was effective in removing 89.06 % of aflatoxin B1 (AFB1) at 50 °C. Model fitting indicated that AFB1 removal was a spontaneous exothermic reaction. This research will lay the foundation for the development of efficient and green antimicrobial and toxin-reducing materials.

Competitive encapsulation of multiple heavy metals by magnesium potassium phosphate cement: Hydration characteristics and leaching toxicity properties.

Magnesium potassium phosphate cement (MKPC) is increasingly used in the solidification/stabilization (SS) of heavy metal (HM) pollutants. However, research on composite HM pollutants remains limited. In this study, four heavy metals (Pb/Zn/Cu/Cd) were individually and simultaneously introduced into MKPC systems with different magnesium/phosphorus (M/P) molar ratios. The introduction of HMs altered the extent of hydration and morphology of MgKPO4·6H2O. Among the MKPC pastes, those with M/P = 2 and 3 had the highest HM solidification efficiency and strength, respectively. The HM solidification efficiency of all specimens exceeded 99 %. In samples with M/P = 3, the codoping of four HMs slightly increased the M/P ratio, thereby increasing MgKPO4·6H2O content and enhancing strength. Pb could generate additional low-solubility precipitates, such as PbHPO4, Pb3 (PO4)2, Pb5 (OH) (PO4)3, and Pb (OH)2, which easily accumulated in pores and were encapsulated by MgKPO4·6H2O, leading to the highest solidification efficiency of Pb by MKPC. Pb and Cu could also form the composite phosphate products Pb2Cu (PO4)3 (OH)·4H2O, thus promoting the S/S effect of Cu. Therefore, the use of MKPC with M/P ratio of 2-3 for the S/S of complex pollutants containing Pb and Cu is a promising approach.

Copper-doped magnesium phosphate nanopowders for critical size calvarial bone defect intervention.

Calvarial defects of bone present difficult clinical situations, and their restoration using biocompatible materials requires special treatments that enable bone regeneration. Magnesium phosphate (MgP) is known as an osteoinductive biomaterial because it contains Mg2+ ions and P ions that enhance the activity of osteoplast cells and help in bone regeneration. In this study, MgP and CuO-doped MgP were fabricated and characterized for their physicomechanical properties, particle size, morphology, surface area, antibacterial test, and in vitro bioactivity evaluation using the following techniques: X-rays diffraction, Fourier-transformer infrared, TEM, and Brunauer, Emmett and Teller (BET) surface area, X-rays photoelectron spectroscopy (XPS), and Scanning electron microscopy (SEM). Furthermore, these nanopowders were implanted in adult inbred male Wistar rats and studied after two periods (28 and 56 days). The results demonstrated that the obtained semiamorphous powders are in nanoscale (≤ 50 nm). XPS analysis ensured the preparation of MgP as mono MgP and CuO were incorporated in the structure as Cu2+ . The bioactivity was supported by the observation of calcium phosphate layer on the nanopowders' surface. The in vivo study demonstrated success of MgP nanopowders especially those doped with CuO in restoration of calvarial defect bone. Therefore, fabricated biomaterials are of great potential in restoration of bone calvarial defects.