Pristine/magnesium-loaded biochar and ZVI affect rice grain arsenic speciation and cadmium accumulation through different pathways in an alkaline paddy soil.

Cadmium (Cd) and arsenic (As) co-contamination has threatened rice production and food safety. It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors. Mg-loaded biochar with outstanding adsorption capacity for As and Cd was used for the first time to remediate Cd/As contaminated paddy soils. In addition, the effect of zero-valent iron (ZVI) on grain As speciation accumulation in alkaline paddy soils was first investigated. The effect of rice straw biochar (SC), magnesium-loaded rice straw biochar (Mg/SC), and ZVI on concentrations of Cd and As speciation in soil porewater and their accumulation in rice tissues was investigated in a pot experiment. Addition of SC, Mg/SC and ZVI to soil reduced Cd concentrations in rice grain by 46.1%, 90.3% and 100%, and inorganic As (iAs) by 35.4%, 33.1% and 29.1%, respectively, and reduced Cd concentrations in porewater by 74.3%, 96.5% and 96.2%, respectively. Reductions of 51.6% and 87.7% in porewater iAs concentrations were observed with Mg/SC and ZVI amendments, but not with SC. Dimethylarsinic acid (DMA) concentrations in porewater and grain increased by a factor of 4.9 and 3.3, respectively, with ZVI amendment. The three amendments affected grain concentrations of iAs, DMA and Cd mainly by modulating their translocation within plant and the levels of As(III), silicon, dissolved organic carbon, iron or Cd in porewater. All three amendments (SC, Mg/SC and ZVI) have the potential to simultaneously mitigate Cd and iAs accumulation in rice grain, although the pathways are different.

An injectable magnesium-loaded hydrogel releases hydrogen to promote osteoporotic bone repair via ROS scavenging and immunomodulation.

Background: The repair of osteoporotic bone defects remains challenging due to excessive reactive oxygen species (ROS), persistent inflammation, and an imbalance between osteogenesis and osteoclastogenesis. Methods: Here, an injectable H2-releasing hydrogel (magnesium@polyethylene glycol-poly(lactic-co-glycolic acid), Mg@PEG-PLGA) was developed to remodel the challenging bone environment and accelerate the repair of osteoporotic bone defects. Results: This Mg@PEG-PLGA gel shows excellent injectability, shape adaptability, and phase-transition ability, can fill irregular bone defect areas via minimally invasive injection, and can transform into a porous scaffold in situ to provide mechanical support. With the appropriate release of H2 and magnesium ions, the 2Mg@PEG-PLGA gel (loaded with 2 mg of Mg) displayed significant immunomodulatory effects through reducing intracellular ROS, guiding macrophage polarization toward the M2 phenotype, and inhibiting the IκB/NF-κB signaling pathway. Moreover, in vitro experiments showed that the 2Mg@PEG-PLGA gel inhibited osteoclastogenesis while promoting osteogenesis. Most notably, in animal experiments, the 2Mg@PEG-PLGA gel significantly promoted the repair of osteoporotic bone defects in vivo by scavenging ROS and inhibiting inflammation and osteoclastogenesis. Conclusions: Overall, our study provides critical insight into the design and development of H2-releasing magnesium-based hydrogels as potential implants for repairing osteoporotic bone defects.

Degradation Behavior of Medical MgZZC-1 in Various Simulated Body Fluids.

Magnesium-based biodegradable metal bone implants exhibit superior mechanical properties compared to biodegradable polymers for orthopedic and cardiovascular stents. In this study, MgZZC-x (x = 1, 1.2) alloys were screened by in vitro biocompatibility tests in three simulated body fluids under nontoxic conditions. The MgZZC-1 alloys with better biocompatibility were selected to predict the days required for complete degradation. The evolution of degradation products was analyzed, and the mechanism of formation of the product film was inferred. A degradation kinetic model was established to investigate the effect of MEM components on the degradation of the alloys. The results demonstrate that the proteins in MEM can greatly retard the degradation progress by attaching to the surface of MgZZC-1 alloys, which are predicted to degrade completely within 341 days. The carbonate and phosphate buffers were adjusted to pH in MEM solution, delaying the degradation of magnesium alloys. This process in MEM more accurately reflects the actual degradation in the body and is superior to that in Hanks and SBF solutions. This study will promote the application of biodegradable materials in clinical medicine.

A Divalent Metal Cation-Metabolite Interaction Model Reveals Cation Buffering and Speciation.

I present the perspective that the divalent metalome and the metabolome can be modeled as a network of chelating interactions instead of separate entities. I review progress in understanding the complex cellular environment, in particular recent contributions to modeling metabolite-Mg2+ interactions. I then demonstrate a simple extension of these strategies based approximately on intracellular Escherichia coli concentrations. This model is composed of four divalent metal cations with a range of cellular concentrations and physical properties (Mg2+, Ca2+, Mn2+, and Zn2+), eight representative metabolites, and interaction constants. I applied this model to predict the speciation of divalent metal cations between free and metabolite-chelated species. This approach reveals potentially beneficial properties, including maintenance of free divalent metal cations at biologically relevant concentrations, buffering of free divalent metal cations, and enrichment of functional metabolite-chelated species. While currently limited by available interaction coefficients, this modeling strategy can be generalized to more complex systems. In summary, biochemists should consider the potential of cellular metabolites to form chelating interactions with divalent metal cations.

Unraveling the influence of CRISPR/Cas13a reaction components on enhancing trans-cleavage activity for ultrasensitive on-chip RNA detection.

The CRISPR/Cas13 nucleases have been widely documented for nucleic acid detection. Understanding the intricacies of CRISPR/Cas13's reaction components is pivotal for harnessing its full potential for biosensing applications. Herein, we report on the influence of CRISPR/Cas13a reaction components on its trans-cleavage activity and the development of an on-chip total internal reflection fluorescence microscopy (TIRFM)-powered RNA sensing system. We used SARS-CoV-2 synthetic RNA and pseudovirus as a model system. Our results show that optimizing Mg2+ concentration, reporter length, and crRNA combination significantly improves the detection sensitivity. Under optimized conditions, we detected 100 fM unamplified SARS-CoV-2 synthetic RNA using a microtiter plate reader. To further improve sensitivity and provide a new amplification-free RNA sensing toolbox, we developed a TIRFM-based amplification-free RNA sensing system. We were able to detect RNA down to 100 aM. Furthermore, the TIRM-based detection system developed in this study is 1000-fold more sensitive than the off-coverslip assay. The possible clinical applicability of the system was demonstrated by detecting SARS-CoV-2 pseudovirus RNA. Our proposed sensing system has the potential to detect any target RNA with slight modifications to the existing setup, providing a universal RNA detection platform.

Mechanism of phosphate release from actin filaments.

After ATP-actin monomers assemble filaments, the ATP's [Formula: see text]-phosphate is hydrolyzedwithin seconds and dissociates over minutes. We used all-atom molecular dynamics simulations to sample the release of phosphate from filaments and study residues that gate release. Dissociation of phosphate from Mg2+ is rate limiting and associated with an energy barrier of 20 kcal/mol, consistent with experimental rates of phosphate release. Phosphate then diffuses within an internal cavity toward a gate formed by R177, as suggested in prior computational studies and cryo-EM structures. The gate is closed when R177 hydrogen bonds with N111 and is open when R177 forms a salt bridge with D179. Most of the time, interactions of R177 with other residues occlude the phosphate release pathway. Machine learning analysis reveals that the occluding interactions fluctuate rapidly, underscoring the secondary role of backdoor gate opening in Pi release, in contrast with the previous hypothesis that gate opening is the primary event.

Electrochemical and statistical study of Nickel ion assessment in daily children intake samples relying on magnesium aluminate spinel nanoparticles.

Lately, children's daily consumption of some products, such as cereals and candies, has been rising, which provides a compelling rationale for determining any metallic substances that may be present. Monitoring the concentration of certain metals, like nickel, in these products is necessary due to medical issues in humans when consumed regularly. So, in this work, a novel and highly selective carbon paste as a Ni(II) ion-selective sensor was prepared and investigated using ceramic magnesium aluminum spinel nanoparticles as the ionophore and tritolyl phosphate (TOCP) as a plasticizer. A modified co-precipitation method was used to synthesize the spinel nanoparticles. X-ray diffraction, scanning electron microscope with EDAX, transmission electron microscope, and BET surface area were used to determine the phase composition, microstructure, pores size, particle size, and surface area of the synthesized nanoparticles. The spinel nanoparticle was found to have a nano crystallite size with a cubic crystal system, a particle size ranging from 17.2 to 51.52 nm, mesoporous nature (average pore size = 8.72 nm), and a large surface area (61.75 m2/g). The composition ratio of graphite carbon as a base: TOCP as binder: spinal as ionophore was 67.3:30.0:2.7 (wt%) based on potentiometric detections over concentrations from 5.0 × 10-8 to 1.0 × 10-2 mol L-1 with LOD of 5.0 × 10-8 mol L-1. A measurement of 29.22 ± 0.12 mV decade-1 over pH 2.0-7.0 was made for the Nernstian slope. This sensor demonstrated good repeatability over nine weeks and a rapid response of 8 s. A good selectivity was shown for Ni(II) ions across many interferents, tri-, di-, and monovalent cations. The Ni(II) content in spiked real samples, including cocaine, sweets, coca, chocolate, carbonated drinks, cereals, and packages, were measured. The results obtained indicated no significant difference between the proposed potentiometric method and the officially reported ICP method according to the F- and t-test data. In addition to utilizing ANOVA statistical analysis, validation procedures have been implemented, and the results exceed the ICP-MS methodology.

Synthesis, characterization, and phosphorus adsorption of Mg/Fe-modified biochar from cotton stalk pretreated with Coriolus versicolor.

In recent years, the research potential in utilizing biochars as adsorbents in adsorption processes has grown due to their eco-friendly and economical nature. However, biochar often possesses a negative surface charge that limits its affinity for binding anions. Nitric acid washing and pretreatment with Coriolus versicolor can break down the lignocellulosic structure in cotton stalk waste, facilitating the subsequent impregnation of Mg and Fe metal oxides. These pretreatment steps can lead to the production of diverse and functionalized biochars with higher adsorption capacities. In this study, cotton stalk waste was first washed with diluted nitric acid and then subjected to biological pretreatment by incubation with C. versicolor, followed by impregnation with Mg and Fe to obtain CV-CS/Fe and CV-CS/Mg biochars. The results showed that the applied pretreatments altered the physicochemical properties and significantly increased the phosphorus adsorption capacity. The adsorption capacities of CV-CS/Fe and CV-CS/Mg biochars were found to be 277.88 and 507.01 mg g-1, respectively. The results indicate that the incorporation of multiple metal oxide impregnates enhances P adsorption. Furthermore, in the kinetic study, pseudo-first-order and pseudo-second-order models provided a well fit, determining chemical adsorption as the main adsorption mechanism for phosphorus adsorption. The biochars demonstrated compatibility with Langmuir-Freundlich models. Overall, the findings suggest the possibility of synthesizing biochars with improved adsorptive properties through pretreatment, and these engineered biochars hold promising potential as effective adsorbents in the field. PRACTITIONER POINTS: Eco-friendly, natural, and economical biochar was synthesized. Biochar was produced via Coriolus versicolor pretreatment. High adsorption capacities of CV-PS/Mg biochars were found to be 507.01 mg g-1. Adsorption capacities of biochars can be improved by pretreatment.

Development of implantable electrode based on bioresorbable Mg alloy for tissue welding application.

An implantable electrode based on bioresorbable Mg-Nd-Zn-Zr alloy was developed for next-generation radiofrequency (RF) tissue welding application, aiming to reduce thermal damage and enhance anastomotic strength. The Mg alloy electrode was designed with different structural features of cylindrical surface (CS) and continuous long ring (LR) in the welding area, and the electrothermal simulations were studied by finite element analysis (FEA). Meanwhile, the temperature variation during tissue welding was monitored and the anastomotic strength of welded tissue was assessed by measuring the avulsion force and burst pressure. FEA results showed that the mean temperature in the welding area and the proportion of necrotic tissue were significantly reduced when applying an alternating current of 110 V for 10 s to the LR electrode. In the experiment of tissue welding ex vivo, the maximum and mean temperatures of tissues welded by the LR electrode were also significantly reduced and the anastomotic strength of welded tissue could be obviously improved. Overall, an ideal welding temperature and anastomotic strength which meet the clinical requirement can be obtained after applying the LR electrode, suggesting that Mg-Nd-Zn-Zr alloy with optimal structure design shows great potential to develop implantable electrode for next-generation RF tissue welding application.

Granulation compared to co-application of biochar plus mineral fertilizer and its impacts on crop growth and nutrient leaching.

Mechanized biochar field application remains challenging due to biochar's poor flowability and bulk density. Granulation of biochar with fertilizer provides a product ready for application with well-established machinery. However, it's unknown whether granulated biochar-based fertilizers (gBBF) are as effective as co-application of non-granulated biochar with fertilizer. Here, we compared a gBBF with a mineral compound fertilizer (control), and with a non-granulated biochar that was co-applied at a rate of 1.1 t ha-1 with the fertilizer in a white cabbage greenhouse pot trial. Half the pots received heavy rain simulation treatments to investigate nutrient leaching. Crop yields were not significantly increased by biochar without leaching compared to the control. With leaching, cabbage yield increased with gBBF and biochar-co-application by 14% (p > 0.05) and 34% (p < 0.05), respectively. Nitrogen leaching was reduced by 26-35% with both biochar amendments. Biochar significantly reduced potassium, magnesium, and sulfur leaching. Most nitrogen associated with gBBF was released during the trial and the granulated biochar regained its microporosity. Enriching fertilizers with biochar by granulation or co-application can improve crop yields and decrease nutrient leaching. While the gBBF yielded less biomass compared to biochar co-application, improved mechanized field application after granulation could facilitate the implementation of biochar application in agriculture.

Exploring the physicochemical traits, antifungal capabilities, and 3D spatial complexity of hydroxyapatite with Ag+Mg2+ substitution in the biocomposite thin films.

The silver/magnesium doped hydroxyapatite (AgMgHAp, Ca10-x-yAgxMgy(PO4)6(OH)2, xAg=0.05 and yMg=0.02) nanocomposites coatings were deposited on Si substrate using the dip coating technique. The resulting coatings were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR-ATR) spectroscopy, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The EDS analysis highlighted the presence of the constitutive elements of the silver/magnesium doped hydroxyapatite (AgMgHAp) nanocomposites coatings. The surface microtexture of the AgMgHAp was assessed by atomic force microscopy (AFM) technique. The AFM data suggested the obtaining of a uniform deposited layer comprised of equally distributed nanoconglomerates. FT-IR studies highlighted the presence of vibrational modes associated with the phosphate and hydroxyl groups. No bands associated with silver or magnesium were observed. The XPS analysis highlighted the presence of the constituent elements of hydroxyapatite (Ca 2p, P 2 s, O 1 s), as well as dopants (Ag 3d, Mg 1 s and Mg 2p). The antifungal evaluation of AgMgHAp coatings was carried out using the Candida albicans ATCC 10231 fungal strain. The results of the antifungal assay revealed that the AgMgHAp coatings exhibited a strong inhibitory antifungal activity. Furthermore, the data highlighted that the AgMgHAp inhibited the development of biofilm on their surface. The results revealed that the antifungal activity of the coating varied based on the duration of incubation. On the other hand, the data also showed that AgMgHAp nanocomposites coatings inhibited the fungal cell adhesion and development from the early stages of the incubation. In addition to morphological analysis, we additionally take advantage of AFM images to investigate and explore the domain of fractal and multifractal analysis applied to the films under evaluation. Our studies indicates that nanocomposite coatings made from AgMgHAp demonstrate strong antifungal properties. Our studies indicates that nanocomposite coatings made from AgMgHAp demonstrate strong antifungal properties. These results suggest the potential of AgMgHAp nanocomposite coatings as a promising solution for developing innovative antifungal devices in biomedical applications.

Deciphering magnesium binding site and structure-function insights in a class II sesquiterpene cyclase.

Magnesium ions (Mg2+) are crucial in class II terpene cyclases that utilize substrates with diphosphate groups. Interestingly, these enzymes catalyze reactions without cleaving the diphosphate group, instead initiating the reaction through protonation. In our recent research, we discovered a novel class II sesquiterpene cyclase in Streptomyces showdoensis. Notably, we determined its crystal structure and identified Mg2+ within its active site. This finding has shed light on the previously elusive question of Mg2+ binding in class II terpene cyclases. In this chapter, we outline our methods for discovering this novel enzyme, including steps for its purification, crystallization, and kinetic analysis.

Croscarmellose Sodium as Pelletization Aid in Extrusion-Spheronization.

Only few excipients are known to be suitable as pelletization aids. In this study, the potential use of croscarmellose sodium (CCS) as pelletization aid was investigated. Furthermore, the impact of cations on extrusion-spheronization (ES) of CCS was studied and different grades of CCS were tested. The influence of different cations on the swelling of CCS was investigated by laser diffraction. Mixtures of CCS with lactose monohydrate as filler with or without the inclusion of different cations were produced. The mixtures were investigated by mixer torque rheometry and consequently extruded and spheronized. Resulting pellets were analyzed by dynamic image analysis. In addition, mixtures of different CCS grades with dibasic calcium phosphate anhydrous (DP) and a mixture with praziquantel (PZQ) as filler were investigated. Calcium and magnesium cations caused a decrease of the swelling of CCS and influenced the use of CCS as pelletization aid since they needed to be included for successful ES. Aluminum, however, led to an aggregation of the CCS particles and to failure of extrusion. The inclusion of cations decreased the uptake of water by the mixtures which also reduced the liquid-to-solid-ratio (L/S) for successful ES. This was shown to be dependent on the amount of divalent cations in the mixture. With DP or PZQ as filler, no addition of cations was necessary for a successful production of pellets, however the optimal L/S for ES was dependent on the CCS grade used. In conclusion, CCS can be used as a pelletization aid.

The chemical state of the watershed in Ras Elma region (South of Taza, Morocco) one of the parameters responsible for the decline in the formation of the current travertine formations.

The Ras Elma region, situated to the south of the city of Taza in northern Morocco, boasts abundant travertine formations that continue to develop, albeit selectively in specific sheltered sites. This development is influenced by various parameters, including the role of water chemistry. This article presents a spatio-temporal analysis of various hydrochemical parameters, including conductivity, pH, temperature, magnesium, calcium, and others. It's worth noting that the water from the Ras Elma Vauclusian spring, a key driver of travertinization in the region, is sourced from water infiltrating through faults and flowing into Lake Tompraire, known as Dayat Chikker near the Bab Boudir area. The findings suggest that the water in Ras Elma has turned aggressive, as revealed by the examination of the calcaro-carbonic equilibrium. CaCO3 precipitation occurs predominantly in the summer, significantly impacting the formation of travertines, particularly those of the spring and dam types. However, valley-type travertines exhibit more extensive development compared to the other two types.

Intraocular pressure control efficacy and safety of HA-Mg glaucoma drainage plate implantation in the anterior chamber of rabbit eyes.

The current clinical application of glaucoma drainage devices is made of non-degradable materials. These non-degradable drainage devices often trigger inflammatory responses and scar proliferation, possibly leading to surgical failure. We developed a biodegradable material hydroxyapatite-coated magnesium (HA-Mg) as a glaucoma drainage device. Twelve New Zealand white rabbits were randomly assigned to three groups: HA-Mg drainage plate group (6 right eyes), trabeculectomy group (6 right eyes), and control group (12 left eyes). Results showed that all HA-Mg drainage plates were completely degraded ~4 months postoperatively. At the 5th month postoperatively, there was no statistical difference in the corneal endothelium density between the HA-Mg drainage plate group and the control group (p = 0.857). The intraocular pressure (IOP) level in the HA-Mg drainage plate implantation group was lower than in the other two groups. The trypan blue dye still drained from the anterior chamber to the subconjunctiva 5 months after HA-Mg drainage plate implantation. HE staining revealed the scleral linear aqueous humor drainage channel and anterior synechia were observed after drainage plate completely degraded, with no obvious infiltration with the inflammatory cells. This study showed the safety and efficacy of HA-Mg glaucoma drainage plate in controlling IOP after implantation into the anterior chamber of rabbit eyes.

Magnesium malate-modified calcium phosphate bone cement promotes the repair of vertebral bone defects in minipigs via regulating CGRP.

Active artificial bone substitutes are crucial in bone repair and reconstruction. Calcium phosphate bone cement (CPC) is known for its biocompatibility, degradability, and ability to fill various shaped bone defects. However, its low osteoinductive capacity limits bone regeneration applications. Effectively integrating osteoinductive magnesium ions with CPC remains a challenge. Herein, we developed magnesium malate-modified CPC (MCPC). Incorporating 5% magnesium malate significantly enhances the compressive strength of CPC to (6.18 ± 0.49) MPa, reduces setting time and improves disintegration resistance. In vitro, MCPC steadily releases magnesium ions, promoting the proliferation of MC3T3-E1 cells without causing significant apoptosis, proving its biocompatibility. Molecularly, magnesium malate prompts macrophages to release prostaglandin E2 (PGE2) and synergistically stimulates dorsal root ganglion (DRG) neurons to synthesize and release calcitonin gene-related peptide (CGRP). The CGRP released by DRG neurons enhances the expression of the key osteogenic transcription factor Runt-related transcription factor-2 (RUNX2) in MC3T3-E1 cells, promoting osteogenesis. In vivo experiments using minipig vertebral bone defect model showed MCPC significantly increases the bone volume fraction, bone density, new bone formation, and proportion of mature bone in the defect area compared to CPC. Additionally, MCPC group exhibited significantly higher levels of osteogenesis and angiogenesis markers compared to CPC group, with no inflammation or necrosis observed in the hearts, livers, or kidneys, indicating its good biocompatibility. In conclusion, MCPC participates in the repair of bone defects in the complex post-fracture microenvironment through interactions among macrophages, DRG neurons, and osteoblasts. This demonstrates its significant potential for clinical application in bone defect repair.

Experimental and computational study on morin and its complexes with Mg2+, Mn2+, Zn2+, and Al3+: Coordination and antioxidant properties.

Morin (MRN), an intriguing bioflavonol, has received increasing interest for its antioxidant properties, as have its metal complexes (Mz+-MRN). Understanding their antioxidant behavior is critical to assess their pharmaceutical, nutraceutical potential, and therapeutic impact in the design of advanced antioxidant drugs. To this end, knowing the speciation of different H+-MRN and Mz+-MRN is pivotal to understand and compare their antioxidant ability. In this work, the protonation constant values of MRN under physiological ionic strength and temperature conditions (I = 0.15 mol L-1 and t = 37 °C), determined by UV-vis spectrophotometric titrations, are introduced. Thus, a reliable speciation model on H+-MRN species in aqueous solution is presented, which exhibits five stable forms depending on pH, supplemented by quantum-mechanical calculations useful to determine the proton affinities of each functional group and corresponding deprotonation order. Furthermore, potentiometry and UV-vis spectrophotometry have been exploited to determine the thermodynamic interaction parameters of MRN with different metal cations (Mg2+, Mn2+, Zn2+, Al3+). The antioxidant ability of H+-MRN and Mz+-MRN has been evaluated by the 2,2'-diphenyl-1-benzopyran-4-one (DPPH) method, and the Zn2+-MRN system has proven to afford the most potent antioxidant effect. Ab initio molecular dynamics simulations of Mz+-MRN species at all possible chelation sites and under explicit water solvation allowed for the fine characterization not only of the metal chelation modalities of MRN in explicit water, but also of the role played by the local water environment around the metal cations. Those microscopic patterns reveal to be informative on the different antioxidant capabilities recorded experimentally.

Sustained Release of Hydrogen and Magnesium Ions Mediated by a Foamed Gelatin-Methacryloyl Hydrogel for the Repair of Bone Defects in Diabetes.

Diabetic bone defects, exacerbated by hyperglycemia-induced inflammation and oxidative stress, present significant therapeutic challenges. This study introduces a novel injectable scaffold, MgH2@PLGA/F-GM, consisting of foamed gelatin-methacryloyl (GelMA) and magnesium hydride (MgH2) microspheres encapsulated in poly(lactic-co-glycolic acid) (PLGA). This scaffold is uniquely suited for diabetic bone defects, conforming to complex shapes and fostering an environment conducive to tissue regeneration. As it degrades, Mg(OH)2 is released and dissolved by PLGA's acidic byproducts, releasing therapeutic Mg2+ ions. These ions are instrumental in macrophage phenotype modulation, inflammation reduction, and angiogenesis promotion, all vital for diabetic bone healing. Additionally, hydrogen (H2) released during degradation mitigates oxidative stress by diminishing reactive oxygen species (ROS). This multifaceted approach not only reduces ROS and inflammation but also enhances M2 macrophage polarization and cell migration, culminating in improved angiogenesis and bone repair. This scaffold presents an innovative strategy for addressing the complexities of diabetic bone defect treatment.

Microenvironment-responsive release of Mg2+ from tannic acid decorated and multilevel crosslinked hydrogels accelerates infected wound healing.

The management of chronic infected wounds poses significant challenges due to frequent bacterial infections, high concentrations of reactive oxygen species, abnormal immune regulation, and impaired angiogenesis. This study introduces a novel, microenvironment-responsive, dual dynamic, and covalently bonded hydrogel, termed OHA-P-TA/G/Mg2+. It is derived from the reaction of tannic acid (TA) with phenylboronic acids (PBA), which are grafted onto oxidized hyaluronic acid (OHA-P-TA), combined with GelMA (G) via a Schiff base and chemical bonds, along with the incorporation of Mg2+. This hydrogel exhibits pH and ROS dual-responsiveness, demonstrating effective antibacterial capacity, antioxidant ability, and the anti-inflammatory ability under distinct acidic and oxidative microenvironments. Furthermore, the release of Mg2+ from the TA-Mg2+ network (TA@Mg2+) promotes the transformation of pro-inflammatory M1 phenotype macrophages to anti-inflammatory M2 phenotype, showing a microenvironment-responsive response. Finally, in vivo results indicate that the OHA-P-TA/G/Mg2+ hydrogel enhances epithelial regeneration, collagen deposition, and neovascularization, showing great potential as an effective dressing for infected wound repair.

Determination of operation parameters for magnesium-air fuel cell to recover nitrogen and phosphorus from wastewater.

Recovering phosphorus (P) and nitrogen (N) from wastewater not only contributes to environmental protection but also aligns with sustainable development goals. This study employed a magnesium-air fuel cell (Mg-O2-FC) to extract P and N from wastewater in the form of struvite (MgNH4·6H2O), based on the removal efficiency of ammonia and phosphate, electricity generation capacity and struvite purity to determine the optimal operation parameters. These parameters included hydraulic retention time (HRT), service life of magnesium sheet, and precipitation discharge frequency. The results showed that the removal efficiency of ammonia from 0 to 4h was 55.99%, and that from 4 to 12h was only 15.74%. The phosphate removal efficiency in the initial cycle was 97.68% but decreased to 63.25% after 24h. The phosphate removal rate in 2 min increased by 145% when the precipitation discharge frequency increased from 4 h/time to 24 h/time. Consequently, the HRT, service life of the magnesium sheet, and precipitation discharge frequency were selected as 4 h, 24 h, and 24 h/time. These optimized conditions provide valuable insights for the practical implementation of Mg-O2-FC in recovering N and P from wastewater.