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.

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

Although calcium‑magnesium 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.

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.

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.

Sintered and 3D-Printed Bulks of MgB2-Based Materials with Antimicrobial Properties

Pristine high-density bulk disks of MgB₂ with added hexagonal BN (10 wt.%) were prepared using spark plasma sintering. The BN-added samples are machinable by chipping them into desired geometries. Complex shapes of different sizes can also be obtained by the 3D printing of polylactic acid filaments embedded with MgB₂ powder particles (10 wt.%). Our present work aims to assess antimicrobial activity quantified as viable cells (CFU/mL) vs. time of sintered and 3D-printed materials. In vitro antimicrobial tests were performed against the bacterial strains Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923, Enterococcus faecium DSM 13590, and Enterococcus faecalis ATCC 29212; and the yeast strain Candida parapsilosis ATCC 22019. The antimicrobial effects were found to depend on the tested samples and microbes, with E. faecium being the most resistant and E. coli the most susceptible.

Neurotrophic Effect of Magnesium Comenate in Normal and under Conditions of Oxidative Stress in Culture of Chicken Spinal Ganglia

The neurotrophic properties of magnesium comenate were studied under standard conditions and under conditions of oxidative stress. It was found that magnesium comenate has a stimulating effect on the neurotrophic processes of the spinal ganglia under normal conditions and under conditions of oxidative stress. Under standard conditions, magnesium comenate exhibits neurotrophic activity at a concentration of 0.0001 mM, under conditions of oxidative stress, magnesium comenate exhibits neurotrophic activity at concentration 0.1 mM.

Toward Tailoring the Degradation Rate of Magnesium-Based Biomaterials for Various Medical Applications: Assessing Corrosion, Cytocompatibility and Immunological Effects

Magnesium (Mg)-based biomaterials hold considerable promise for applications in regenerative medicine. However, the degradation of Mg needs to be reduced to control toxicity caused by its rapid natural corrosion. In the process of developing new Mg alloys with various surface modifications, an efficient assessment of the relevant properties is essential. In the present study, a WE43 Mg alloy with a plasma electrolytic oxidation (PEO)-generated surface was investigated. Surface microstructure, hydrogen gas evolution in immersion tests and cytocompatibility were assessed. In addition, a novel in vitro immunological test using primary human lymphocytes was introduced. On PEO-treated WE43, a larger number of pores and microcracks, as well as increased roughness, were observed compared to untreated WE43. Hydrogen gas evolution after two weeks was reduced by 40.7% through PEO treatment, indicating a significantly reduced corrosion rate. In contrast to untreated WE43, PEO-treated WE43 exhibited excellent cytocompatibility. After incubation for three days, untreated WE43 killed over 90% of lymphocytes while more than 80% of the cells were still vital after incubation with the PEO-treated WE43. PEO-treated WE43 slightly stimulated the activation, proliferation and toxin (perforin and granzyme B) expression of CD8⁺ T cells. This study demonstrates that the combined assessment of corrosion, cytocompatibility and immunological effects on primary human lymphocytes provide a comprehensive and effective procedure for characterizing Mg variants with tailorable degradation and other features. PEO-treated WE43 is a promising candidate for further development as a degradable biomaterial.

An upgraded and universal strategy to reinforce chitosan/polyvinylpyrrolidone film by incorporating active silica nanorods derived from natural palygorskite

Active silica nanorod (OPal) was prepared from natural palygorskite (RPal) using an updated acid leaching route, and then the effect of RPal and OPal as nano-filler on the network structure, mechanical, thermal and anti-aging properties of chitosan/polyvinylpyrrolidone (CS/PVP) films was studied comparatively. It was revealed that OPal had a better dispersibility than RPal in CS/PVP substrate, and its incorporation improved the mechanical properties and thermal stability of the films significantly. The optimal composite film containing OPal shows the maximum tensile strength of 27.53 MPa (only 14.87 MPa and 22.47 MPa for CS/PVP and CS/PVP/RPal films, respectively), resulting from the more uniform dispersion of OPal in polymer substrate and its stronger interaction with 3D polymer network. By a controllable acid-leaching process, the metal ions in octahedral sheets of RPal were dissolved out continuously, which is favorable to alleviate the adverse effects of variable metal ions on the film under UV light irradiation, and thus improve the aging-resistant ability of films. This study provides new ideas for improving the reinforcing ability of natural clay minerals towards biopolymer-based material, finds a new way to resolve the aging problem of polymer composites caused by incorporation of natural clay minerals.

Effect of Attapulgite-Doped Electrospun Fibrous PLGA Scaffold on Pro-Osteogenesis and Barrier Function in the Application of Guided Bone Regeneration

PURPOSE

Guided bone regeneration (GBR) therapy, which is a widely used technique in clinical practice and is effective in improving the repair of alveolar bone defects or bone mass deficiency regeneration, requires the use of membrane materials with good biocompatibility, barrier function, rigidity matching the space maintenance ability, economic benefits and excellent clinical applicability. The aim of this study was to develop an electrospun attapulgite (ATT)-doped poly (lactic-co-glycolic acid) (PLGA) scaffold (PLGA/ATT scaffold) as a novel material for GBR applications.

METHODS AND RESULTS

Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to determine the morphology and the crystalline structure of the PLGA/ATT scaffolds, respectively. Porosity and contact-angle measurements were also carried out to further characterize the physical properties of the PLGA/ATT scaffolds. The results of in vitro studies showed that bone marrow mesenchymal stem cells (BMSCs) attached more readily to and spread better over the PLGA/ATT scaffolds than the Bio-Gide membrane. Furthermore, in the in vitro osteoinductive experiments with BMSCs, the PLGA/ATT scaffolds were found to enhance the activity of alkaline phosphatase (ALP), promote the formation of mineralized bone nodules, and up-regulate the expression of several osteogenic markers-namely, runt-related transcription factor 2, alkaline phosphatase, osteopontin, and osteocalcin-which are similar to the effects of the Bio-Gide membrane. Further, in in vivo studies, the results of sequential fluorescent labeling, micro-computed tomography, and histological analysis suggest that using the PLGA/ATT scaffolds for repairing V-shaped buccal dehiscence on a dog's tooth root improved bone regeneration, which is not only similar to the result obtained using the Bio-Gide membrane but also much better than that obtained using PLGA scaffolds and the negative control.

CONCLUSION

To achieve satisfactory therapeutic results and to lower the cost of GBR treatment, this study provided a promising alternative material of bio-degradable membrane in clinical treatment.

The combined antibacterial and anticancer properties of nano Ce-containing Mg-phosphate ceramic

AIM

This paper was mainly aimed at synthesis of Ce-containing nano-Mg-phosphate ceramic as a multifunctional material.

MATERIALS AND METHODS

Two ceramics based on Mg₃(PO₄)₂ and Ce_0.2Mg_2.8(PO₄)₂ formulas (MP and MP-C, respectively) were synthesized. The synthesized powders were characterized by XRD, TEM, Zeta potential, and FTIR. Also, their dissolution behavior was tested in Tris-HCl buffer solution. Moreover, the antimicrobial efficacy was evaluated against gram-positive bacteria (Bacillus sphaericus MTCC 511 &Staphylococcus aureus MTCC 87) and gram-negative bacteria (Enterobacter aerogenes MTCC 111 &Pseudomonas aeruginosa MTCC 1034) using dick diffusion assay and microdilution method. Furthermore, the cell viability test was performed for the ceramics on Vero cells (African green monkey kidney cells), and their antitumor activity was determined by PC3 cell line (prostatic cancer). Also, the cellular uptake was determined by the flow cytometry.

KEY FINDINGS

The results showed that the substitution of Mg by Ce decreased the particle size from 40 to 90 nm for MP sample to 2-10 nm for MP-C sample and increased the degradation rate. Both samples showed excellent antimicrobial activities. Moreover, MP demonstrated more cell viability than MP-C on Vero cells at high concentrations, whereas, MP-C showed more antitumor activity on PC3 cells than MP sample. Moreover, MP-C showed a higher cell uptake than MP due to its smaller size and more negative charge.

SIGNIFICANCE

Mg-phosphate ceramic can be used in this study successfully as a delivery system for cerium ions and showed a high antitumor activity, which makes it highly recommended as safe and effective cancer treatment materials.

Application of encapsulated magnesium peroxide (MgO2) nanoparticles in permeable reactive barrier (PRB) for naphthalene and toluene bioremediation from groundwater

One of the challenges in the petroleum hydrocarbon contaminated groundwater remediation by oxygen releasing compounds (ORCs) is to identify the remediation mechanism and determine the impact of ORCs on the environment and the intrinsic groundwater microorganisms. In this research, the application of encapsulated magnesium peroxide (MgO₂) nanoparticles in the permeable reactive barrier (PRB) for bioremediation of the groundwater contaminated by toluene and naphthalene was studied in the continuous flow sand-packed plexiglass columns within 50 d experiments. For the biodiversity studies, next generation sequencing (NGS) of the 16S rRNA gene was applied. The results showed that naphthalene was metabolized (within 20 days) faster than toluene (after 30 days) by microorganisms of the aqueous phase. By comparing the contaminant removal in the biotic (which resulted in the complete contaminant removal) and abiotic (around 32% removal for naphthalene and 36% for toluene after 50 d) conditions, the significant role of microorganisms on the decontamination process was proved. Furthermore, the attached microbial communities on the porous media were visualized by scanning electron microscopy (SEM). Microbial community structure analysis by NGS technique revealed that the microbial species which were able to degrade toluene and naphthalene such as P. putida and P. mendocina respectively were stimulated by addition of MgO₂ nanoparticles. The presented study resulted in a momentous insight into the application of MgO₂ nanoparticles in the hydrocarbon compounds removal from groundwater.

Effect of Polyacrylamide/Attapulgite Composite on Foraging Behaviors of Formosan Subterranean Termites (Blattodea: Rhinotermitidae)

Moisture conditions of food and soil are essential for the survival and foraging activities of subterranean termites. Polyacrylamide/attapulgite composite is a water-retaining agent that has been applied to increase moisture of agricultural soils. We hypothesize that polyacrylamide/attapulgite composite may increase the moisture of bait matrixes and soil surrounding baiting containers and therefore attract termites and increase their foraging activities. In the present study, aggregation and feeding preferences, survivorship, body water percentage, and wood consumption of Formosan subterranean termites, Coptotermes formosanus Shiraki (Blattodea: Rhinotermitidae), were investigated when responding to polyacrylamide/attapulgite composite that was buried within soil (substrate) or filled in the void volume of baiting containers. Two-choice tests showed that termites consumed significantly more wood when polyacrylamide/attapulgite composite was buried within dry soil (27%-moisture) than the controls (no polyacrylamide/attapulgite composite was provided). However, polyacrylamide/attapulgite composite buried within wet soil (54%-moisture) did not significantly affect foraging behaviors of termites. Multiple-choice tests showed no aggregation or feeding preference of termites in the baiting containers filled with polyacrylamide/attapulgite composite compared with the soil-filled or unfilled ones, whenever the substrate was dry or wet. No-choice tests showed that the presence of polyacrylamide/attapulgite composite (buried within soil or filled in baiting containers) significantly increased wood consumption and body water percentage of termites as well as wood moisture under dry-substrate conditions. Our studies suggest that burying polyacrylamide/attapulgite composite within dry soil may enhance foraging activities of termites, but filling the bait stations with polyacrylamide/attapulgite composite may not effectively attract termites.

Effects of Modified Palygorskite Supplementation on Egg Quality and Mineral Element Content, and Intestinal Integrity and Barrier Function of Laying Hens

This study was conducted to investigate effects of modified palygorskite (MPal) supplementation on the laying performance, egg quality and mineral element content, immunity, oxidative status, and intestinal integrity and barrier function of laying hens. A total of 360 52-week-old Hyline Brown hens were randomly assigned into four dietary treatments for a 7-week feeding trial. The birds were fed a basal diet supplemented with 0 (control group), 0.25, 0.5, and 1 g/kg MPal, respectively. The supplementation of MPal did not alter laying performance and egg quality among groups. Compared with the control group, MPal inclusion decreased lead (Pb) content in yolks at 49 days, and either 0.5- or 1-g/kg MPal supplementation decreased Pb accumulation in yolks at 25 days and manganese (Mn) accumulation in yolks at 25 and 49 days. The contents of jejunal secretory immunoglobulin A (SIgA), ileal SIgA, and immunoglobulin G were decreased by the dietary 0.5-g/kg MPal supplementation. The supplementation of MPal also decreased malondialdehyde content in jejunum and ileum, and decreased serum diamine oxidase activity of the laying hens at 25 and 49 days. The inclusion of 0.5 and 1 g/kg MPal enhanced villus height in jejunum and ileum, and also increased the ratio of villus height to crypt depth in ileum. In conclusion, MPal supplementation decreased Pb and Mn contents in yolks, and exhibited beneficial effects on the intestinal immunity, oxidative status, and intestinal integrity and barrier function of laying hens and its optimal dosage was 0.5 g/kg.

Control of metabolic predisposition to cardiovascular complications of chronic kidney disease by effervescent calcium magnesium citrate: a feasibility study

Aims

Cardiovascular (CV) complications are common in chronic kidney disease (CKD). Numerous metabolic disturbances including hyperphosphatemia, high circulating calciprotein particles (CPP), hyperparathyroidism, metabolic acidosis, and magnesium deficiency are associated with, and likely pathogenic for CV complications in CKD. The goal of this feasibility study was to determine whether effervescent calcium magnesium citrate (EffCaMgCit) ameliorates the aforementioned pathogenic intermediates.

Methods

Nine patients with Stage 3 and nine patients with Stage 5D CKD underwent a randomized crossover study, where they took EffCaMgCit three times daily for 7 days in one phase, and a conventional phosphorus binder calcium acetate (CaAc) three times daily for 7 days in the other phase. Two-hour postprandial blood samples were obtained on the day before and on the 7th day of treatment.

Results

In Stage 5D CKD, EffCaMgCit significantly increased T50 (half time for conversion of primary to secondary CPP) from baseline by 63% (P = 0.013), coincident with statistically non-significant declines in serum phosphorus by 25% and in saturation of octacalcium phosphate by 35%; CaAc did not change T50. In Stage 3 CKD, neither EffCaMgCit nor CaAc altered T50. With EffCaMgCit, a significant increase in plasma citrate was accompanied by statistically non-significant increase in serum Mg and phosphate. CaAc was without effect in any of these parameters in Stage 3 CKD. In both Stages 3 and 5D, both drugs significantly reduced serum parathyroid hormone. Only EffCaMgCit significantly increased serum bicarbonate by 3 mM (P = 0.015) in Stage 5D.

Conclusions

In Stage 5D, EffCaMgCit inhibited formation of CPP, suppressed PTH, and conferred magnesium and alkali loads. These effects were unique, since they were not observed with CaAc. In Stage 3 CKD, neither of the regimens have any effect. These metabolic changes suggest that EffCaMgCit might be useful in protecting against cardiovascular complications of CKD by ameliorating pathobiologic intermediates.

Comparing the Effects of Chitosan Scaffolds Containing Various Divalent Metal Phosphates on Osteogenic Differentiation of Stem Cells from Human Exfoliated Deciduous Teeth

Inducing the differentiation of stem cells from human exfoliated deciduous teeth (SHEDs) proceeds with low efficiency, which greatly limits clinical applications. Divalent metal elements play an important role in osteoinductivity for bone remodeling because they can simulate bone formation and decrease bone resorption. The purpose of this study was to investigate the effect of some divalent metal phosphates on osteogenic differentiation from human exfoliated deciduous teeth. These divalent metal ions can be gradually released from the scaffold into the culture medium and continually induce osteoblastic differentiation. Experimental results revealed that SHEDs cultured in chitosan scaffolds containing divalent metal phosphates had notably increased osteoblastic differentiation compared with cells cultured without divalent metal phosphates. This effect was due to the high activity of alkaline phosphatase, as well as the bone-related gene expression of collagen type I, Runx2, osteopontin, osteocalcin, VEGF, and Ang-1, shown through RT-PCR and bone-related protein immunocytochemistry stains. A calcium-content assay further revealed significant enhancement of deposited minerals on the scaffolds after 21 days of culture, particularly for magnesium phosphate and zinc phosphate. Thus, divalent metals, except for barium phosphate, effectively promoted SHED cell differentiation and osteoblastic cell maturation. This study demonstrated that the divalent metal elements magnesium, strontium, and zinc could effectively induce SHED osteoblastic differentiation for use in tissue engineering and bone repair.

Effects of sintering temperature on surface morphology/microstructure, in vitro degradability, mineralization and osteoblast response to magnesium phosphate as biomedical material

Magnesium phosphate (MP) was fabricated using a chemical precipitation method, and the biological performances of MP sintered at different temperatures as a biomedical material was investigated. The results indicated that the densification and crystallinity of MP increased as the sintering temperature increased. As the sintering temperature increased, the degradability of MP in PBS decreased, and the mineralization ability in SBF significantly increased. In addition, the MP sintered at 800 °C (MP8) possessed the lowest degradability and highest mineralization ability. Moreover, the positive response of MG63 cells to MP significantly increased as the sintering temperature increased, and MP8 significantly promoted the cell spreading, proliferation, differentiation and expressions of osteogenic differentiation-related genes. Faster degradation of MP0 resulted in higher pH environments and ion concentrations, which led to negative responses to osteoblasts. However, the appropriate degradation of MP8 resulted in suitable pH environments and ion concentrations, which led to positive responses to osteoblasts. This study demonstrated that the sintering temperature substantially affected the surface morphology/microstructure, degradability and mineralization, and osteoblasts response to magnesium phosphate.

In vitro and in vivo evaluation of MgF2 coated AZ31 magnesium alloy porous scaffolds for bone regeneration

Porous magnesium scaffolds are attracting increasing attention because of their degradability and good mechanical property. In this work, a porous and degradable AZ31 magnesium alloy scaffold was fabricated using laser perforation technique. To enhance the corrosion resistance and cytocompatibility of the AZ31 scaffolds, a fluoride treatment was used to acquire the MgF₂ coating. Enhanced corrosion resistance was confirmed by immersion and electrochemical tests. Due to the protection provided by the MgF₂ coating, the magnesium release and pH increase resulting from the degradation of the FAZ31 scaffolds were controllable. Moreover, in vitro studies revealed that the MgF₂ coated AZ31 (FAZ31) scaffolds enhanced the proliferation and attachment of rat bone marrow stromal cells (rBMSCs) compared with the AZ31 scaffolds. In addition, our present data indicated that the extract of the FAZ31 scaffold could enhance the osteogenic differentiation of rBMSCs. To compare the in vivo bone regenerative capacity of the AZ31 and FAZ31 scaffolds, a rabbit femoral condyle defect model was used. Micro-computed tomography (micro-CT) and histological examination were performed to evaluate the degradation of the scaffolds and bone volume changes. In addition to the enhanced the corrosion resistance, the FAZ31 scaffolds were more biocompatible and induced significantly more new bone formation in vivo. Conversely, bone resorption was observed from the AZ31 scaffolds. These promising results suggest potential clinical applications of the fluoride pretreated AZ31 scaffold for bone tissue repair and regeneration.

Effects of Palygorskite Inclusion on the Growth Performance, Meat Quality, Antioxidant Ability, and Mineral Element Content of Broilers

The present study was conducted to investigate different levels of palygorskite supplementation on the growth performance, meat quality, muscular oxidative status, and mineral element accumulation of broilers. One hundred ninety-two 1-day-old Arbor Acres broiler chicks were allocated to four dietary treatments with six replicates of eight chicks per replicate. Birds in the four treatments were given a basal diet supplemented with 0, 5, 10 and 20 g/kg palygorskite for 42 days, respectively. Compared with the control group, neither 5 g/kg nor 10 g/kg palygorskite inclusion affected growth performance of broilers during the 42-day study (P > 0.05). However, the highest level of palygorskite supplementation at 20 g/kg increased feed/gain ratio (F/G) of broilers (P < 0.001). Yellowness (P < 0.001) and redness (P = 0.003) of breast muscle and yellowness of leg muscle (P = 0.001) were decreased by palygorskite supplementation at the levels of 10 g/kg and especially 20 g/kg. In addition, redness of leg muscle was also reduced by the inclusion of 20 g/kg palygorskite (P = 0.009). In contrast, malonaldehyde (MDA) accumulation in the breast muscle was significantly increased by 20 g/kg palygorskite supplementation (P < 0.001). Supplementation of palygorskite at either 10 or 20 g/kg significantly decreased lead (Pb) accumulation in the breast (P = 0.001) or thigh (P = 0.045) and copper (Cu) accumulation in the breast (P = 0.022). In conclusion, growth performance, meat color, and antioxidant capacity of meat would reduce with the increasing level of palygorskite supplementation, whereas a higher level of palygorskite (10 or 20 g/kg) can alter mineral element accumulations in muscles as evidenced by reduced muscular Cu and Pb contents.

Efficacy of scalp hair decontamination following exposure to vapours of sulphur mustard simulants 2-chloroethyl ethyl sulphide and methyl salicylate

Chemical warfare agents are an actual threat and victims' decontamination is a main concern when mass exposure occurs. Skin decontamination with current protocols has been widely documented, as well as surface decontamination. However, considering hair ability to trap chemicals in vapour phase, we investigated hair decontamination after exposure to sulphur mustard simulants methyl salicylate and 2-chloroethyl ethyl sulphide. Four decontamination protocols were tested on hair, combining showering and emergency decontamination (use of Fuller's earth or Reactive Skin Decontamination Lotion RSDL^®). Both simulants were recovered from hair after treatment, but contents were significantly reduced (42-85% content allowance). Showering alone was the least efficient protocol. Concerning 2-chloroethyl ethyl sulphide, protocols did not display significant differences in decontamination efficacy. For MeS, use of emergency decontaminants significantly increased showering efficacy (10-20% rise), underlining their usefulness before thorough decontamination. Our results highlighted the need to extensively decontaminate hair after chemical exposure. Residual amounts after decontamination are challenging, as their release from hair could lead to health issues.

Synthesis, characterization, and in-vitro cytocompatibility of amorphous β-tri-calcium magnesium phosphate ceramics

Biphasic mixtures of crystalline β-tricalcium magnesium phosphate (β-TCMP) and an amorphous calcium magnesium phosphate have been synthesized and reported to support enhanced hMSC differentiation in comparison to β-tricalcium phosphate (β-TCP) due to the release of increased amounts of bioactive ions. In the current study, completely amorphous β-TCMP has been synthesized which is capable of releasing increased amounts of Mg(2+) and PO4(3-) ions, rather than a biphasic mixture as earlier reported. The amorphous phase formed was observed to crystallize between temperatures of 400-600°C. The scaffolds prepared with amorphous β-TCMP were capable of supporting enhanced hMSC proliferation and differentiation in comparison to commercially available β-TCP. However, a similar gene expression of mature osteoblast markers, OCN and COL-1, in comparison to biphasic β-TCMP was observed. To further study the role of Mg(2+) and PO4(3-) ions in regulating hMSC osteogenic differentiation, the capability of hMSCs to mineralize in growth media supplemented with Mg(2+) and PO4(3-) ions was studied. Interestingly, 5mM PO4(3-) supported mineralization while the addition of 5mM Mg(2+) to 5mM PO4(3-) inhibited mineralization. It was therefore concluded that the release of Ca(2+) ions from β-TCMP scaffolds also plays a role in regulating osteogenic differentiation on these scaffolds and it is noted that further work is required to more accurately determine the exact role of Mg(2+) in regulating hMSC osteogenic differentiation.

A new magnesium bisulfite pretreatment (MBSP) development for bio-ethanol production from corn stover

This study established a new more neutral magnesium bisulfate pretreatment (MBSP) using magnesium bisulfate as sulfonating agent for improving the enzymatic hydrolysis efficiency of corn stover. Using the MBSP with 5.21% magnesium bisulfate, 170°C and pH 5.2 for 60 min, about 90% of lignin and 80% of hemicellulose were removed from biomass and more than 90% cellulose conversion of substrate was achieved after 48 h hydrolysis. About 6.19 kg raw corn stover could produce 1 kg ethanol by Saccharomyces cerevisiae. Meanwhile, MBSP also could protect sugars from excessive degradation, prevent fermentation inhibition formation and directly convert the hemicelluloses into xylooligosaccharides as higher-value products. These results suggested that the MBSP method offers an alternative approach to the efficient conversion of nonwoody lignocellulosic biomass to ethanol and had broad space for development.

Remediation of Cr(VI) contaminated soil using long-duration sodium thiosulfate supported by micro-nano networks

In this work, a long-duration remediation agent (LRA) on hexavalent chromium (Cr(VI)) was developed using sodium thiosulfate (ST) supported by attapulgite (ATP) micro-nano networks induced through high-energy electron beam (HEEB) irradiation. The ATP networks could effectively reduce the leaching amount of Cr(VI) in soil. More importantly, the ATP networks could significantly control the leaching behavior of ST, and then prolong the duration and increase the reduction efficiency of ST on Cr(VI). As a result, LRA displayed high performance on controlling the migration of Cr(VI) and reducing Cr(VI) to Cr(III). Additionally, pot experiment indicated that LRA could effectively decrease the absorbed amount of Cr(VI) in corn, and reduce the inhibition effect of Cr(VI) on the growth of corn. Therefore, this work could provide a facile approach to remediate the Cr(VI)-contaminated soil and lower the harmful effect of Cr(VI) on crop.

Comparative angioprotective effects of magnesium compounds

Magnesium (Mg) deficiency is implicated in the development of numerous disorders of the cardiovascular system. Moreover, the data regarding the efficacy of different magnesium compounds in the correction of impaired functions due to low magnesium intake are often fragmentary and inconsistent. The aim of this study was to compare the effects of the most bioavailable Mg compounds (Mg l-aspartate, Mg N-acetyltaurate, Mg chloride, Mg sulphate and Mg oxybutyrate) on systemic inflammation and endothelial dysfunction in rats fed a low Mg diet for 74 days. A low Mg diet decreased the Mg concentration in the plasma and erythrocytes, which was accompanied by a reduced concentration of eNOs and increased levels of endothelin-1 level in the serum and impaired endothelium-dependent vasodilatation. These effects increased the concentration of proinflammatory molecules, such as VCAM-1, TNF-α, IL-6 and CRP, indicating the development of systemic inflammation and endothelial dysfunction. The increased total NO level, which estimated from the sum of the nitrate and nitrite concentrations in the serum, may also be considered to be a proinflammatory marker. Two weeks of Mg supplementation partially or fully normalised the ability of the vascular wall to effect adequate endothelium-dependent vasodilatation and reversed the levels of most endothelial dysfunction and inflammatory markers (except CRP) to the mean values of the control group. Mg sulphate had the smallest effect on the endothelin-1, TNF-α and VCAM-1 levels. Mg N-acetyltaurate was significantly more effective in restoring the level of eNOS compared to all other studied compounds, except for Mg oxybutyrate. Taken together, the present findings demonstrate that all Mg compounds equally alleviate endothelial dysfunction and inflammation caused by Mg deficiency. Mg sulphate tended to be the least effective compound.

Transparent magnesium aluminate spinel: a prospective biomaterial for esthetic orthodontic brackets

Adult orthodontics is recently gaining popularity due to its importance in esthetics, oral and general health. However, none of the currently available alumina or zirconia based ceramic orthodontic brackets meet the esthetic demands of adult patients. Inherent hexagonal lattice structure and associated birefringence limits the visible light transmission in polycrystalline alumina and make them appear white and non transparent. Hence focus of the present study was to assess the feasibility of using magnesium aluminate (MgAl2O4) spinel; a member of the transparent ceramic family for esthetic orthodontic brackets. Transparent spinel specimens were developed from commercially available white spinel powder through colloidal shaping followed by pressureless sintering and hot isostatic pressing at optimum conditions of temperature and pressure. Samples were characterized for chemical composition, phases, density, hardness, flexural strength, fracture toughness and optical transmission. Biocompatibility was evaluated with in-vitro cell line experiments for cytotoxicity, apoptosis and genotoxicity. Results showed that transparent spinel samples had requisite physico-chemical, mechanical, optical and excellent biocompatibility for fabricating orthodontic brackets. Transparent spinel developed through this method demonstrated its possibility as a prospective biomaterial for developing esthetic orthodontic brackets.

Tailoring Mg(x)Mn(1-x)Fe(2)O(4) superparamagnetic nanoferrites for magnetic fluid hyperthermia applications

A superparamagnetic nanoferrite (SPNF) with high magnetic moment, AC magnetically induced heating (AC-heating) capacity, and good biocompatibility is the most vital part of magnetic fluid hyperthermia for utilizing it in the clinics. Herein, we precisely tune magnetic properties and AC-heating characteristics of MgxMn1-xFe2O4 SPNF via chemically controlling the cations' concentration and distribution to develop a tailored MgxMn1-xFe2O4 SPNF as a potential magnetic fluid hyperthermia agent. The magnetic and AC-heating characteristics of the tailored MgxMn1-xFe2O4 SPNF are strongly dependent on the Mg/Mn cations' concentration and distribution, and Mg0.285Mn0.715Fe2O4 SPNF exhibits the highest saturation magnetization and AC-heating capacity as well as high biocompatibility.

Influence of fluoride treatment on surface properties, biodegradation and cytocompatibility of Mg-Nd-Zn-Zr alloy

Fluoride treatment is a commonly used technique or pre-treatment to optimize the degradation kinetic and improve the biocompatibility of magnesium-based implant. The influence of changed surface properties and degradation kinetics on subsequent protein adsorption and cytocompatibility is critical to understand the biocompatibility of the implant. In this study, a patent magnesium alloy Mg-Nd-Zn-Zr alloy (JDBM) designed for cardiovascular stent application was treated by immersion in hydrofluoric acid. A 1.5 μm thick MgF2 layer was prepared. The surface roughness was increased slightly while the surface zeta potential was changed to a much more negative value after the treatment. Static contact angle test was performed, showing an increase in hydrophilicity and surface energy after the treatment. The MgF2 layer slowed down in vitro degradation rate, but lost the protection effect after 10 days. The treatment enhanced human albumin adsorption while no difference of human fibrinogen adsorption amount was observed. Direct cell adhesion test showed many more live HUVECs retained than bare magnesium alloy. Both treated and untreated JDBM showed no adverse effect on HUVEC viability and spreading morphology. The relationship between changed surface characteristics, degradation rate and protein adsorption, cytocompatibility was also discussed.

[Effects of magnesium on the onset time of rocuronium in patients for cesarean delivery]

BACKGROUND

Although magnesium can potentially shorten onset time of a muscle relaxant, it is unclear whether it does shorten the onset time of rocuronium for patients in cesarean delivery (CD). Thus the purpose of this study is to compare the onset time of rocuronium in patients with or without preoperative magnesium treatment.

METHODS

In 9 CD patients without magnesium (CD group) and 8 CD patients with magnesium (CD-Mg group), neuromuscular function was continuously assessed with acceleromyography immediately after induction of general anesthesia with intravenous injection of thiopental (4-5 mg x kg(-1)) and rocuronium (0.6 mg x kg(-1)). Onset time of muscle relaxation, defined by the time from rocuronium bolus injection until complete absence of twitch height, was measured.

RESULTS

The onset time of both groups did not significantly differ (50 +/- 10 seconds vs. 51 +/- 11 seconds; P = 0.93, unpaired t-test). Median magnesium concentration, 5.2 mg x dl(-1) (3.8-6.3), and the onset time of CD-Mg group did not correlate magnesium concentrations (P = 0.23, Pearson's correlation coefficient test).

CONCLUSIONS

Magnesium did not shorten the onset time of rocuronium 0.6 mg x kg(-1) in CD patients.

Optimization of struvite fertilizer formation from baker's yeast wastewater: growth and nutrition of maize and tomato plants

Struvite precipitate obtained from yeast industry anaerobic effluent with high ammonium nitrogen (NH4-N) was investigated for fertilizer effect on plant growth and nutrition according to applications of N, nitrogen/phosphorus/potassium (NPK), and control. Optimum struvite formation conditions were determined via Box-Behnken design. Optimum condition was obtained at pH 9.0 and Mg/N/P molar ratio of 1.5:1:1. Under these conditions, heavy metal concentrations in the obtained struvite precipitate (except Cu) were below the detection limits. In addition to high N, P, and Mg content, energy-dispersive X-ray (EDX) analysis showed that the struvite also included the nutritional elements Ca, K, Na, and Fe. X-ray diffraction (XRD) analysis revealed the complex structures of NaAl(SO4)2(H2O)12, NaMn(2+)Fe2(PO4)3, and (Na2,Ca)O2(Fe,Mn)O.P2O5 in the precipitate. High Na(+) and Ca(2+) concentrations in the anaerobic effluent reacted with phosphate during struvite precipitation. Different applications and struvite dosages significantly affected fresh and dry weights and nutrient element uptakes by plants (P < 0.05). N, P, and Mg uptakes of plants were significantly higher at struvite ×2, ×3, and ×4 dosages compared with NPK application. For adequate nutrition and supply of optimum dry weight, struvite ×2 dosage (5.71 g struvite/kg soil) was found appropriate for both maize and tomato plants.

Cytocompatibility evaluation of different biodegradable magnesium alloys with human mesenchymal stem cells

In the last few years, the use of biodegradable magnesium (Mg) alloys has evoked great interest in the orthopedic field due to great advantages over long-term implant materials associated with various side effects like allergy and sensitization and consequent implant removal surgeries. However, degradation of these Mg alloys results in ion release, which may cause severe cytotoxicity and undesirable complications after implantation. In this study, we investigated the cytological effects of various Mg alloys on cells that play an important role in bone repair. Eight different magnesium alloys containing varying amounts of Al, Zn, Nd and Y were either incubated directly or indirectly with the osteosarcoma cell line Saos-2 or with uninduced and osteogenically-induced human mesenchymal stem cells (MSCs) isolated from bone marrow specimens obtained from the femoral shaft of patients undergoing total hip replacement. Cell viability, cell attachment and the release of ions were investigated at different time points in vitro. During direct or indirect incubation different cytotoxic effects of the Mg alloys on Saos-2 cells and osteogenically-induced or uninduced MSCs were observed. Furthermore, the concentration of degradation products released from the Mg alloys differed. Overall, Mg alloys MgNd2, MgY4, MgAl9Zn1 and MgY4Nd2 exhibit good cytocompatibility. In conclusion, this study reveals the necessity of cytocompatibility evaluation of new biodegradable magnesium alloys with cells that will get in direct contact to the implant material. Furthermore, the use of standardized experimental in vitro assays is necessary in order to reliably and effectively characterize new Mg alloys before performing in vivo experiments.

Biodiesel production from Jatropha oil catalyzed by immobilized Burkholderia cepacia lipase on modified attapulgite

Lipase from Burkholderia cepacia was immobilized on modified attapulgite by cross-linking reaction for biodiesel production with jatropha oil as feedstock. Effects of various factors on biodiesel production were studied by single-factor experiment. Results indicated that the best conditions for biodiesel preparation were: 10 g jatropha oil, 2.4 g methanol (molar ratio of oil to methanol is 1:6.6) being added at 3h intervals, 7 wt% water, 10 wt% immobilized lipase, temperature 35°C, and time 24h. Under these conditions, the maximum biodiesel yield reached 94%. The immobilized lipase retained 95% of its relative activity during the ten repeated batch reactions. The half-life time of the immobilized lipase is 731 h. Kinetics was studied and the Vmax of the immobilized lipases were 6.823 mmol L(-1). This immobilized lipase catalyzed process has potential industrial use for biodiesel production to replace chemical-catalyzed method.

Antimicrobial properties and dentin bonding strength of magnesium phosphate cements

The main objective of this work was to assess the antimicrobial properties and the dentin-bonding strength of novel magnesium phosphate cements (MPC). Three formulations of MPC, consisting of magnesium oxide and a phosphate salt, NH4H2PO4, NaH2PO4 or a mixture of both, were evaluated. As a result of the setting reaction, MPC transformed into either struvite (MgNH4PO4·6H2O) when NH4H2PO4 was used or an amorphous magnesium sodium phosphate when NaH2PO4 was used. The MPC had appropriate setting times for hard tissue applications, high early compressive strengths and higher strength of bonding to dentin than commercial mineral trioxide aggregate cement. Bacteriological studies were performed with fresh and aged cements against three bacterial strains, Escherichia coli, Pseudomonas aeruginosa (planktonic and in biofilm) and Aggregatibacter actinomycetemcomitans. These bacteria have been associated with infected implants, as well as other frequent hard tissue related infections. Extracts of different compositions of MPC had bactericidal or bacteriostatic properties against the three bacterial strains tested. This was associated mainly with a synergistic effect between the high osmolarity and alkaline pH of the MPC. These intrinsic antimicrobial properties make MPC preferential candidates for applications in dentistry, such as root fillers, pulp capping agents and cavity liners.

Bacteria-adsorbed palygorskite stabilizes the quaternary phosphonium salt with specific-targeting capability, long-term antibacterial activity, and lower cytotoxicity

In order to extend the antibacterial time of quaternary phosphonium salt in bacteria, palygorskite (PGS) is used as the carrier of dodecyl triphenyl phosphonium bromide (DTP), and a DTP-PGS hybrid is prepared. Antibacterial performance of this novel hybrid is investigated for both Gram-positive and Gram-negative bacteria. The results show that the DTP could be absorbed on the surface of PGS which had bacteria-adsorbed capability. The DTP-PGS hybrid, combining the advantages of PGS and DTP, display specific-targeting capability, long-term antibacterial activity, and lower cytotoxicity, suggesting the great potential application as PGS-based antibacterial powder.

Olivine weathering in soil, and its effects on growth and nutrient uptake in Ryegrass (Lolium perenne L.): a pot experiment

Mineral carbonation of basic silicate minerals regulates atmospheric CO(2) on geological time scales by locking up carbon. Mining and spreading onto the earth's surface of fast-weathering silicates, such as olivine, has been proposed to speed up this natural CO(2) sequestration ('enhanced weathering'). While agriculture may offer an existing infrastructure, weathering rate and impacts on soil and plant are largely unknown. Our objectives were to assess weathering of olivine in soil, and its effects on plant growth and nutrient uptake. In a pot experiment with perennial ryegrass (Lolium perenne L.), weathering during 32 weeks was inferred from bioavailability of magnesium (Mg) in soil and plant. Olivine doses were equivalent to 1630 (OLIV1), 8150, 40700 and 204000 (OLIV4) kg ha(-1). Alternatively, the soluble Mg salt kieserite was applied for reference. Olivine increased plant growth (+15.6%) and plant K concentration (+16.5%) in OLIV4. At all doses, olivine increased bioavailability of Mg and Ni in soil, as well as uptake of Mg, Si and Ni in plants. Olivine suppressed Ca uptake. Weathering estimated from a Mg balance was equivalent to 240 kg ha(-1) (14.8% of dose, OLIV1) to 2240 kg ha(-1) (1.1%, OLIV4). This corresponds to gross CO(2) sequestration of 290 to 2690 kg ha(-1) (29 10(3) to 269 10(3) kg km(-2).) Alternatively, weathering estimated from similarity with kieserite treatments ranged from 13% to 58% for OLIV1. The Olsen model for olivine carbonation predicted 4.0% to 9.0% weathering for our case, independent of olivine dose. Our % values observed at high doses were smaller than this, suggesting negative feedbacks in soil. Yet, weathering appears fast enough to support the 'enhanced weathering' concept. In agriculture, olivine doses must remain within limits to avoid imbalances in plant nutrition, notably at low Ca availability; and to avoid Ni accumulation in soil and crop.

Antibiofilm surface functionalization of catheters by magnesium fluoride nanoparticles

The ability of bacteria to colonize catheters is a major cause of infection. In the current study, catheters were surface-modified with MgF(2) nanoparticles (NPs) using a sonochemical synthesis protocol described previously. The one-step synthesis and coating procedure yielded a homogenous MgF(2) NP layer on both the inside and outside of the catheter, as analyzed by high resolution scanning electron microscopy and energy dispersive spectroscopy. The coating thickness varied from approximately 750 nm to 1000 nm on the inner walls and from approximately 450 nm to approximately 580 nm for the outer wall. The coating consisted of spherical MgF(2) NPs with an average diameter of approximately 25 nm. These MgF(2) NP-modified catheters were investigated for their ability to restrict bacterial biofilm formation. Two bacterial strains most commonly associated with catheter infections, Escherichia coli and Staphylococcus aureus, were cultured in tryptic soy broth, artificial urine and human plasma on the modified catheters. The MgF(2) NP-coated catheters were able to significantly reduce bacterial colonization for a period of 1 week compared to the uncoated control. Finally, the potential cytotoxicity of MgF(2) NPs was also evaluated using human and mammalian cell lines and no significant reduction in the mitochondrial metabolism was observed. Taken together, our results indicate that the surface modification of catheters with MgF(2) NPs can be effective in preventing bacterial colonization and can provide catheters with long-lasting self-sterilizing properties.

[Pharmacotherapy for preventing calcium containing stone formation]

Many urinary tract stones consist of calcium, and has high relapse rate. Accordingly, it is very important to prevent calcium-containing stone formation. This paper describes about effects and mechanisms for Xanthine oxidase inhibitor, citrate formulation, magnesium formulation, thiazides, vitamin B(6), extract of Quercus salicina Blume and chorei-to (medical herb) . Recent new drugs and the elucidation of new metabolic pathways may lead to the development of prevention of urolithiasis.

[Effects of magnesium salts on the course of experimental calcium-oxalate urolithiasis]

Experimental urolithiasis was induced in 80 white non-inbred male rats by adding 0.75% ethylene glycol and 2% ammonium chloride to drinking water by Fan et al. After significant differences in crystalluria, oxaluria and urine pH were achieved in hyperoxaluric rats vs controls one, hyperoxaluric rats were given magnesium (Mg) salts Mg chloride, Mg L-aspartate either alone or in combination with pyridoxine hydrochloride (B6) in comparison with Mg sulfate and magne B6 (mg lactate in combination with B6) in a dose of 50 mg of elementary Mg per 1 kg of body weight. All the rats were fed with Mg-adequate diet containing 0.84 g of Mg oxide (0.5 g of elementary Mg per kg of diet). Calcium-oxalate urolithiasis has developed in rats taking ethylene glycol and ammonium chloride for 28 days. An urinary oxalates levels increased threefold, oxalate/creatinine--fourfold. Calcium oxalate crystals were detected in the urine of rats drinking solution of ethylene glycol and ammonium chloride, pH decreased by 20%, fractional excretion (FE) of Mg increased by 60%, FE of phosphate--by 58.2%, FE of calcium--by 95.8%, creatinine clearance lowered by 39.2% in comparison with intact group. Magnesium salts administration resulted in reduction of urine oxalates, crystalluria, phosphate excretion, Ca/Mg and oxalate/creatinine ratios, increased urine pH and creatinine clearance. Mg L-aspartate in combination with vitamin B6 appeared the most effective salt and significantly more effective than magnesium sulfate.

Low temperature fabrication of magnesium phosphate cement scaffolds by 3D powder printing

Synthetic bone replacement materials are of great interest because they offer certain advantages compared with organic bone grafts. Biodegradability and preoperative manufacturing of patient specific implants are further desirable features in various clinical situations. Both can be realised by 3D powder printing. In this study, we introduce powder-printed magnesium ammonium phosphate (struvite) structures, accompanied by a neutral setting reaction by printing farringtonite (Mg(3)(PO(4))(2)) powder with ammonium phosphate solution as binder. Suitable powders were obtained after sintering at 1100°C for 5 h following 20-40 min dry grinding in a ball mill. Depending on the post-treatment of the samples, compressive strengths were found to be in the range 2-7 MPa. Cytocompatibility was demonstrated in vitro using the human osteoblastic cell line MG63.

In vivo corrosion and corrosion protection of magnesium alloy LAE442

The aim of this study was to investigate whether the extruded magnesium alloy LAE442 reacts in vivo with an appropriate host response and to investigate how an additional magnesium fluoride (MgF(2)) coating influences the in vivo corrosion rate. Forty cylinders were machined from extruded LAE442 and 20 of these were coated additionally with MgF(2) and implanted into the medial femur condyle of adult rabbits. Synchrotron-radiation-based X-ray computed micro-tomography (SRmicroCT) was used to quantitatively analyse corrosion non-destructively in vivo and comparisons were made to magnesium degradation rates based on area measurements of the remaining metal on uncalcified sections. Blood concentrations of the alloying elements were measured below toxicological limits. The MgF(2) layer was no longer detected after 4 weeks of implantation by particle-induced gamma emission, and the MgF(2) coating reduced the blood content of alloying elements during the first 6 weeks of implantation with no elevated fluoride concentration in the adjacent bone. Histopathological examinations of liver showed in 9 out of 40 cases minimal infiltrations of heterophil granulocytes of unknown origin (5 LAE442, 4 LAE442+MgF(2)). The kidneys were mainly regular in structure. The synovial tissue showed a granular cell infiltration as a temporary observation in the LAE442+MgF(2) group after 2 weeks. No subcutaneous gas cavities were observed clinically and on postoperative X-rays in all animals. All specimens were scanned by SRmicroCT at 2, 4, 6 and 12 weeks postoperatively before uncalcified sections were performed. All magnesium implants have been observed in direct bone contact and without a fibrous capsule. Localized pitting corrosion occurred in coated and uncoated magnesium implants. This study shows that the extruded magnesium alloy LAE442 provides low corrosion rates and reacts in vivo with an acceptable host response. The in vivo corrosion rate can be further reduced by additional MgF(2) coating.

Influence of magnesium aluminium silicate on rheological, release and permeation characteristics of diclofenac sodium aqueous gels in-vitro

The effect of magnesium aluminium silicate (MAS) on rheological, release and permeation characteristics of diclofenac sodium (DS) aqueous gels was investigated. DS aqueous gels were prepared using various gelling agents, such as 15% w/w poloxamer 407 (PM407), 1% w/w hydroxypropylmethylcellulose (HPMC), and 1% w/w high and low viscosity grades of sodium alginate (HV-SA and LV-SA, respectively). Different amounts of MAS (0.5, 1.0 and 1.5% w/w) were incorporated into the DS gels. Incorporation of MAS into the DS gels prepared using SA or PM407 caused a statistical increase in viscosity (P&lt;0.05) and a shift from Newtonian flow to pseudoplastic flow with thixotropic property. The DS release rates of these composite gels were significantly decreased (P&lt;0.05) when compared with the control gels. This was due to an interaction between MAS and PM407 or SA, and adsorption of DS onto MAS particles. Moreover, a longer lag time and no change in DS permeation flux were found when MAS was added to the gels. The findings suggest that the rheological characteristics of gels prepared using PM407 or SA could be improved by incorporating MAS. However, the use of MAS could retard the DS release and extend the lag time of DS permeation.

[Chemotactic and adhesive properties of Azotobacter vinelandii and Bacillus subtilis]

The effects of some factors on the chemotaxis of Azotobacter vinelandii IMV V-7076 and Bacillus subtilis IMV V-7023 and on their adhesion to cucumber roots have been studied. Glucose chemotaxis and adhesion to roots reach peak values in pH ranges characteristic of each strain. These ranges are 7.0-8.0 for A. vinelandii IMV V-7076 and 6.0-7.0 for B. subtilis IMV V-7023. The adhesion values of each species decrease significantly in their mixed suspension. The interaction of each of the strains with the clay mineral montmorillonite improves their adhesion to cucumber roots. The clay mineral palygorskite improves the adhesion of A. vinelandii but reduces that of B. subtilis.

Use of an oxygen-releasing compound to aerate eutrophic reservoir water

This study examined the use of an Oxygen Release Compound (ORC) as a slow release chemical aeration agent within eutrophic surface water systems. Bench and pilot-scale experiments involving ORC treatment of eutrophic reservoir water were conducted to determine operational properties of ORC and examine its performance as an aeration agent within a surface water environment. The bench-scale study involved the application of 10, 25 and 50 g ORC doses to 1 L Erlenmeyer flasks containing various water and sediment samples. The pilot-scale study involved a scaled up simulation of full-scale reservoir systems using large fiberglass tanks, where water quality parameters in an ORC-treated tank were compared to an untreated tank over a 4 month period. The results of these experiments indicate that the application of ORC can result in substantial increases in dissolved oxygen and pH when applied to deoxygenated water systems. Within the pilot scale study, a 300 g/m2 dose of ORC at the sediment water interface prevented the onset of anoxic conditions over a 4 month growing season period, releasing approximately 20% of its mass as oxygen within this time frame.

[Effects of bischofit-based ointment on the tensile strength of scar tissues in infected and uninfected skin wounds]

[Bischofit-based ointment was found to produce a stimulatory effect on the regeneration processes in wounds and the biomechanical properties of scar tissues in both infected and uninfected wounds]

Kinetic analysis of beta-phosphoglucomutase and its inhibition by magnesium fluoride

The isomerization of beta-glucose-1-phosphate (betaG1P) to beta-glucose-6-phosphate (G6P) catalyzed by beta-phosphoglucomutase (betaPGM) has been examined using steady- and presteady-state kinetic analysis. In the presence of low concentrations of beta-glucose-1,6-bisphosphate (betaG16BP), the reaction proceeds through a Ping Pong Bi Bi mechanism with substrate inhibition (kcat = 65 s(-1), K(betaG1P) = 15 microM, K(betaG16BP) = 0.7 microM, Ki = 122 microM). If alphaG16BP is used as a cofactor, more complex kinetic behavior is observed, but the nonlinear progress curves can be fit to reveal further catalytic parameters (kcat = 74 s(-1), K(betaG1P) = 15 microM, K(betaG16BP) = 0.8 microM, Ki = 122 microM, K(alphaG16BP) = 91 microM for productive binding, K(alphaG16BP) = 21 microM for unproductive binding). These data reveal that variations in the substrate structure affect transition-state affinity (approximately 140,000-fold in terms of rate acceleration) substantially more than ground-state binding (110-fold in terms of binding affinity). When fluoride and magnesium ions are present, time-dependent inhibition of the betaPGM is observed. The concentration dependence of the parameters obtained from fitting these progress curves shows that a betaG1P x MgF3(-) x betaPGM inhibitory complex is formed under the reaction conditions. The overall stability constant for this complex is approximately 2 x 10(-16) M(5) and suggests an affinity of the MgF3(-) moiety to this transition-state analogue (TSA) of < or = 70 nM. The detailed kinetic analysis shows how a special type of TSA that does not exist in solution is assembled in the active site of an enzyme. Further experiments show that under the conditions of previous structural studies, phosphorylated glucose only persists when bound to the enzyme as the TSA. The preference for TSA formation when fluoride is present, and the hydrolysis of substrates when it is not, rules out the formation of a stable pentavalent phosphorane intermediate in the active site of betaPGM.

Successful transfer of plasmid DNA into in vitro cells transfected with an inorganic plasmid-Mg/Al-LDH nanobiocomposite material as a vector for gene expression

The delivery of a full plasmid, encoding the green fluorescent protein gene into African monkey kidney (Vero3) cells, was successfully achieved using nanobiocomposites based on layered double hydroxides. This demonstrated the potential of using the system as an alternative DNA delivery vector. Intercalation of the circular plasmid DNA, pEGFP-N2, into Mg/Al-NO(3)(-) layered double hydroxides (LDH) was accomplished through anion exchange routes to form the nanobiocomposite material. The host was previously synthesized at the Mg(2+) to Al(3+) molar ratio R(i) = 2 and subsequently intercalated with plasmid DNA. Size expansion of the interlamellae host from 8.8 A in LDH to 42 A was observed in the resulting nanobiocomposite, indicating stable hybridization of the plasmid DNA. The powder x-ray diffraction (PXRD) results, supplemented with Fourier-transform infrared (FTIR) spectroscopy, compositional and electrophoresis studies confirmed the encapsulation episode of the biomaterial. In order to elucidate the use of this resulting nanobiocomposite as a delivery vector, an MTT assay was performed to determine any cytotoxic effects of the host towards cells. The intercalated pEGFP-N2 anion was later successfully recovered through acidification with HNO(3) after treatment with DNA-degrading enzymes, thus also showing the ability of the LDH host to protect the intercalated biomaterial from degradation. Cell transfection studies on Vero3 cells were then performed, where cells transfected with the nanobiocomposite exhibited fluorescence as early as 12 h post-treatment compared to naked delivery of the plasmid itself.

A novel method for predicting chronic nickel bioavailability and toxicity to Daphnia magna in artificial and natural waters

In the present study, the individual effects of Ca, Mg, and pH on the chronic toxicity of Ni to Daphnia magna were examined in a series of 21-d reproduction tests in synthetic test solutions. Based on the linear increase of 21-d median effective concentrations expressed as Ni2+ activity (21-d EC50Ni2+) with increasing activities of Ca2+ and Mg2+, the effects of Ca and Mg were modeled according to single-site competition with log KCaBL = 3.53 and log KMgBL = 3.57 (BL = biotic ligand). Because the increase of 21-d EC50Ni2+ with increasing H+ activity was nonlinear, the effect of pH could not be described appropriately by single-site competition between Ni2+ and H+. Instead, the effect of pH was modeled based on an empirical linear relationship between pH and 21-d EC50pNi2+* (equal to -log [21-d EC50Ni2+ corrected for the presence of Ca and Mg]) and was superimposed on the effects of Ca and Mg. For all test solutions used for model development, the developed model predicted the observed 21-d EC50 expressed as dissolved Ni concentration with an error of less than a factor of two. The importance of dissolved organic carbon in protecting D. magna against chronic Ni toxicity was demonstrated by conducting 21-d reproduction tests in a series of Ni-spiked natural waters. Because the model tended to systematically overestimate chronic Ni toxicity in these natural waters, it was further optimized to yield more accurate predictions in natural waters. Although some room still exists for improvement, the developed model is, to our knowledge, the first to present a useful tool for assessing the risk of Ni to aquatic invertebrates.

Antidepressant activity of zinc and magnesium in view of the current hypotheses of antidepressant action

The clinical efficacy of current antidepressant therapies is unsatisfactory; antidepressants induce a variety of unwanted effects, and, moreover, their therapeutic mechanism is not clearly understood. Thus, a search for better and safer agents is continuously in progress. Recently, studies have demonstrated that zinc and magnesium possess antidepressant properties. Zinc and magnesium exhibit antidepressant-like activity in a variety of tests and models in laboratory animals. They are active in forced swim and tail suspension tests in mice and rats, and, furthermore, they enhance the activity of conventional antidepressants (e.g., imipramine and citalopram). Zinc demonstrates activity in the olfactory bulbectomy, chronic mild and chronic unpredictable stress models in rats, while magnesium is active in stress-induced depression-like behavior in mice. Clinical studies demonstrate that the efficacy of pharmacotherapy is enhanced by supplementation with zinc and magnesium. The antidepressant mechanisms of zinc and magnesium are discussed in the context of glutamate, brain-derived neurotrophic factor (BDNF) and glycogen synthase kinase-3 (GSK-3) hypotheses. All the available data indicate the importance of zinc and magnesium homeostasis in the psychopathology and therapy of affective disorders.

[Effect of some organic and inorganic magnesium salts on lipoprotein state in rats fed with magnesium-deficient diet]

Low serum magnesium (Mg) concentrations have been reported in patients with atherosclerosis. From the other hand numerous clinical reports suggest the beneficial effects of Mg adjuvant therapy for the treatment of atherosclerosis. The purpose of this present study was to compare the effect of Mg L-aspartate and Mg chloride alone and in combinations with pyridoxine, Mg sulfate and Magne B6 (Mg lactate with pyridoxine) on lipid profile in rats fed with Mg deficient diet. To induce hypomagnesemia, fifty-three rats were placed on a Mg-deficient diet (ICN Biomedicals Inc. Aurora, OH) and demineralized water for 7 weeks. Seven control rats were fed a basal control diet (Mg content = 500 mg/kg) and water (with Mg content 20 mg/l) for equal duration. On the forty-ninth day of Mg-deficient diet, rats were treated one of the six supplementations: Mg chloride, Mg L-aspartate alone and in combinations with pyridoxine, Mg sulphate and Magne B6 (50 mg Mg and 5 mg vitamin B6 per kg). In our study Mg deficiency resulted in increase of triglyceride (by 35.2 %p < 0.0001), LDL (more than fourfold p < 0.0001), total cholesterol (by 38.7% p < 0.0001), apolipoprotein B (by 74.1%, p = 0.0006) levels and decrease in concentration of HDL (by 28.7% p < 0.0001). The non-HDL cholesterol/HDL cholesterol ratio was more than threefold increased (p < 0.0001). Oral magnesium salts led to normalization of lipid state with a return to pre-deficient levels. Magnesium salts in combinations with pyridoxine tended to be significantly more effective as compared with salts without pyridoxine. The hypolipidemic effect of studied salts was comparable with those observed in Magne B6 treatment and significantly higher than in magnesium sulfate treatment.

Reduced toxicological activity of cigarette smoke by the addition of ammonia magnesium phosphate to the paper of an electrically heated cigarette: subchronic inhalation toxicology

Cigarette smoke is a complex chemical mixture that causes a variety of diseases, such as lung cancer. With the electrically heated cigarette smoking system (EHCSS), temperatures are applied to the tobacco below those found in conventional cigarettes, resulting in less combustion, reduced yields of some smoke constituents, and decreased activity in some standard toxicological tests. The first generation of electrically heated cigarettes (EHC) also resulted in increased formaldehyde yields; therefore, a second generation of EHC was developed with ammonium magnesium phosphate (AMP) in the cigarette paper in part to address this increase. The toxicological activity of mainstream smoke from these two generations of EHC and of a conventional reference cigarette was investigated in two studies in rats: a standard 90-day inhalation toxicity study and a 35-day inhalation study focusing on lung inflammation. Many of the typical smoke exposure-related changes were found to be less pronounced after exposure to smoke from the second-generation EHC with AMP than to smoke from the first-generation EHC or the conventional reference cigarette, when compared on a particulate matter or nicotine basis. Differences between the EHC without AMP and the conventional reference cigarette were not as prominent. Overall, AMP incorporated in the EHC cigarette paper reduced the inhalation toxicity of the EHCSS more than expected based on the observed reduction in aldehyde yields.

Reduced toxicological activity of cigarette smoke by the addition of ammonium magnesium phosphate to the paper of an electrically heated cigarette: smoke chemistry and in vitro cytotoxicity and genotoxicity

The effects of the addition of ammonium magnesium phosphate (AMP) to the paper of an electrically heated cigarette (EHC) prototype on smoke composition and toxicity were quantified and the underlying mechanisms investigated. Smoke from EHC prototypes with and without AMP and from conventional cigarettes, i.e. the University of Kentucky Standard Reference Cigarette 1R4F and eight American-blend market cigarettes, was compared. Endpoints for comparison were smoke chemistry, where toxic constituents were measured, cytotoxic activity, as measured in murine fibroblasts embryo cells by the Neutral Red Uptake Assay, and genotoxic activity, as measured in bacteria by the Salmonella Reverse Mutation Assay and in murine lymphoma cells by the TK Assay. The addition of AMP to the EHC led to a reduction of toxic substances and toxicological activity of approximately 30% compared to the EHC without AMP. Compared to the conventional cigarettes, the EHC with AMP showed reductions of 75-90%. Smoke from the EHCs generated in nitrogen atmospheres supplemented with different concentrations of ammonia and oxygen was assayed for its in vitro cytotoxicity and genotoxicity. The results indicate that the ammonia released by AMP at the heating site of the EHC is responsible for the reductions in cytotoxicity and mutagenicity for the EHC with AMP compared with the EHC without AMP. Thus, while the EHC approach distinctly reduces toxic smoke constituents compared to conventional cigarettes, the use of AMP in the paper of an EHC leads to further distinct reductions. In the study presented here, in vitro assays were used as quantitative tools to investigate toxicity-related mechanisms.