Abstract Magnesium Research Articles

Impression Creep Characteristics of Mg-Sn-Ag Alloy

Magnesium alloys with enhanced thermal stability are being developed for automobile engine applications. The available commercial Mg-alloys are usually alloyed with aluminum that are thermally stable only for T < 150o C. Development of new Mg-alloys is underway and Mg-Sn alloys are a promising option. In Mg-Sn alloy, the Mg2Sn phase has high thermal stability and is expected to enhance the high temperature properties. In this study, Mg-5Sn alloy is incorporated with Ag as a minor alloying element (0.175 wt. %). The creep behavior of the Mg-Sn-Ag alloy is investigated using the impression creep technique. The impression creep tests were carried out under punching stress in the range of 80-320 MPa and temperature of 373-573 K, for dwell times up to 5 hours. The results highlight that creep of the alloy was load and temperature dependent, i.e. increasing the load and temperature resulted in higher creep rates.

Characterizing magnesium–silicon binaries in Al–Mg–Si supersaturated solid solution by first-principles calculations

Abstract Magnesium silicide Mg2Si is a well-studied binary of Mg and Si due to its potential technological applications like infrared photonic and thermoelectric. In many experimental scenarios, e.g., in supersaturated solid solution of Al–Mg–Si, some other Mg-Si binaries, e.g., Mg9Si5 and Mg5Si6, co-exist with Mg2Si. It was then computationally found that Mg9Si5 and Mg5Si6 are thermodynamically favorable under some non-zero pressures. Other than this, very little is known about these two new binaries. This paper aims to unveil some structural, electronic, and vibrational properties of Mg9Si5 and Mg5Si6, providing some information that may be useful for further possible investigations on the Al–Mg–Si solid solution.

Nanostructured self assembled monolayers on magnesium for improved biological performance

Magnesium (Mg) and its alloys are being extensively investigated for its use as a biodegradable metallic implant material. Surface modification strategies are critical for Mg to be able to address application-specific criterion for applications such as cardiovascular stent, orthopaedic bone screws/plates and as a metallic scaffold for bone tissue engineering. Self-assembled monolayers (SAMs) are nano-sized coatings that present a simple and flexible method of carrying out surface modification of biomaterials to tailor its surface properties for specific end applications without altering the bulk properties of the material. In this manuscript, we present a brief overview of Mg as a biodegradable metallic implant material followed by surface modification of Mg using SAMs.

Influence of Compressive Stress to the Corrosion Rate of Magnesium

Magnesium has made an attention as implant material. Because it is decomposed and absorbed in the body, and its mechanical strength is stronger than that of polymers. It is, however, reported that the corrosion rate increases under the compressive elastic stress. In the other hand, it decreases in the specimen whose surface is applied to compressive residual stress by laser shot peening. This implies that compressive plastic deformation reduces the corrosion rate. In the present paper, the corrosion rate of magnesium that was plastically deformed by uniform high compressive stress was researched. As the result, the corrosion rate decreased as the compressive stress increased.

Plasma Spraying of Al-Si and Silicon on Magnesium Alloy under Protective Atmosphere

Magnesium alloy AZ 91 is widely used as a structural material, but its use is limited at higher temperatures and high humidity. Plasma spraying technology allows to prepare protective metallic and nonmetallic coatings on magnesium and its alloys. In this study magnesium alloy AZ 91 was coated using plasma spraying method by AlSi30 wt. % and silicon. The Al-Si was applied to provide a bond-coat for topmost layer of silicon. This study focused on feeding distance (FD) on the quality of the prepared layers. The layers were prepared with a thickness of about 100 μm. The layers were observed with a scanning electron microscope with elemental map analysis. The layers were measured by Electrochemical impedance spectroscopy.

The in vitro biocompatibility and osteoinductive activity study of magnesium composed PLGA/TCP porous scaffold for bone regeneration

Magnesium is a kind of biodegradable metal and widely concerned for its good mechanical properties and bioactivity ability in biomedical fields, but limited with low corrosion resistance for clinical application. Bioactive ceramic alkaline calcium phosphate (TCP) was proven helpful to bone healing due to its biocompatibility and osteoconductivity. In this study, magnesium powder was incorporated into the mixed solution of poly lactide-co-glycolic acid (PLGA) and TCP, then fabricated PLGA/TCP/Mg composited porous scaffold by low-temperature 3D printing technology to optimized the initial mechanical properties of PLGA/TCP scaffold and yield osteogenesis potential of the scaffold for bone regeneration.

Modification of magnesium silicate with 13(1)-N-methylamide-17-methyl-15-diethylene glycol ester of chlorin е 6

Magnesium silicates modified with 13(1)-N-methylamide-17-methyl-15-diethylene glycol ester of chlorin е 6 have been prepared for the first time via heat treatment. The studies by means of X-ray diffraction analysis, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis have revealed that variation of the synthesis conditions affords products differing in the size, particles morphology, and chlorin concentration.

Enhancing the sorption efficiency of polystyrene by immobilizing MgO and its application for uranium (VI) removal from aqueous solutions

Abstract Magnesium oxide immobilized polystyrene (PS/MgO) was prepared by the thermal attachment method for the removal of U(VI) from aqueous solutions. PS/MgO was characterized by different techniques [scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD)]. The effects of pH, adsorbent amount, contact time, initial U(VI) concentration, temperature and co-existing cations on the removal process were investigated by using batch technique. The results showed that the maximum adsorption capacity was 163 (mg g−1) at pH 6 and 293 K. The adsorption kinetics of U(VI) onto PS/MgO followed pseudo-second order and intra-particle kinetic models. The adsorption isotherms obeyed the Freundlich isotherm model. The thermodynamic parameters show that the process is endothermic and spontaneous. PS/MgO is an attractive adsorbent for U(VI) removal from aqueous solutions due to its accessibility, low preparation cost and high removal capacity

Oral Magnesium Treatment Reduces Anemia and Levels of Inflammatory Markers in Experimental Diabetes

ABSTRACT Magnesium has been reported to improve glucose utilization in diabetes mellitus. However, information on its effects on anemic and inflammatory markers in diabetes mellitus is limited. This study investigated the effect of oral magnesium (Mg) treatment on some markers of anemia and inflammation in 25 male Wistar rats. Rats (200 ± 15 g) were randomly divided into five groups (n = 5). Group 1 was control (received orally 0.2 mL distilled water daily), group 2 (Diabetic Untreated), group 3 (Diabetic Mg treated—100 mg/kg bw), group 4 (Diabetic Mg treated—250 mg/kg bw), group 5 (Diabetic Insulin treated—1 IU/kg bw). Diabetes was induced with a single dose of alloxan (100 mg/kg intraperitoneal (i.p.)). All treatments were done for 14 days. Anemic and inflammatory markers were investigated on blood samples obtained from each animal using standard laboratory methods. Significant increase (p < 0.05) in total white blood cell (WBC) count was observed in diabetic untreated rats (7.67 ± 0.397 × 109/L) compared to control (5.88 ± 0.25 × 109/L), DMg 100 (5.86 ± 0.74 × 109/L) and DMg 250 (5.06 ± 0.78 × 109/L). Hemoglobin concentration, packed cell volume (PCV) and red blood cell (RBC) count was decreased (p < 0.05) in DU compared to control, DMg 100, and DI rats. Erythrocyte sedimentation rate (ESR) was significantly increased (p < 0.05) in DU compared to control, DMg 100, DMg 250, and DI groups. Fibrinogen level was increased (p < 0.05) in DU rats (0.44 ± 0.02 g/dL) compared to control(0.26 ± 0.02 g/dL). Values obtained in DMg 100 (0.30 ± 0.03 g/dL), DMg 250 (0.22 ± 0.04 g/dL), and DI (0.36 ± 0.02 g/dL) rats were comparable to control (0.26 ± 0.02 g/dL). Total protein, albumin, and globulin levels were decreased in DU rats compared to normal control, DMg 100, DMg 250, and DI rats. In conclusion, anemia and increased hematologic and metabolic inflammatory markers may be associated with untreated diabetes mellitus. Treatment of alloxan-induced diabetic rats with magnesium improved the anemic state and reduced hematologic and metabolic inflammatory markers.

STRUCTURAL CHARACTERIZATION OF SULFOBORATE GLASSES CONTAINING MAGNESIUM OXIDE

Magnesium sulfoborate glasses of different compositions were prepared using melt quenching method with the purpose of using it for optical properties. The Fourier Transform Infra-red (FTIR) Spectroscopy, Nuclear Magnetic Resonance (NMR) and X-Ray Diffraction (XRD) have been carried out. Density and molar volume have been evaluated and analysed. From the results of XRD, the absent of discrete and continuous sharp peaks confirmed the amorphous nature of the glass compositions while the results from both FTIR and NMR revealed the existence of BO3, BO4 units. Addition of MgO to sulfoborate influenced the conversion of the dominant BO3 groups to BO4 groups. The BO4 groups are known for creating complex defects that transform into that stable trap good for optical phenomena. It was observed that the density of glass increases while the molar volume is decreases with respect to increase in concentration of alkaline earth oxide in the glass compositions.

Investigation of MgTiO3 as an anode material for rechargeable Li-ion batteries

Magnesium Titanate (MgTiO 3 ) is a common and commercially available dielectric material used in electronics applications. The potential of using MgTiO 3 as an anode material in rechargeable Li-ion batteries has been investigated under this study. MgTiO 3 particles were synthesized by both wet-chemical Pechini method and solid state ball milling method. The subsequent material characterizations were carried out using X-ray diffraction and scanning electron microscopic techniques. The electrochemical performance of MgTiO 3 as an anode material in Li-ion rechargeable battery was carried out with Li metal electrode in coin half cells. For wet-chemically synthesized MgTiO 3 , the potentials associated with lithiation were 1.14 V and 0.76 V vs Li/Li + with an initial discharge capacity of 103 mAh/g at C/10 rate. Lithiation potential for ball milled MgTiO 3 was found to be at 1.3 V vs Li/Li + with an initial discharge of 63 mAh/g cycled at C/10 rate.

PREPARATION OF MAGNESIUM HYDROXIDE NANOPARTICLES FROM BITTERN

Magnesium hydroxide is an important material with high decomposition temperature. It is the important precursor for magnesium oxide. In the present study, nanoparticles of magnesium hydroxide were prepared from bittern. Bittern is the waste liquid formed during the production of salt. Since it is rich in magnesium, magnesium hydroxide nanoparticles can be prepared. The nanoparticles were characterized by SEM, EDS and TG-DTA.

Implementation of diverse non-centrosymmetric layer concepts for tuning the interface activity of a magnesium alloy

Magnesium and its alloys are the lightest metallic materials used for structural applications. Tuning the surface functionalization of magnesium alloys may contribute to increasing their durability. Dry or wet processes may be effective for the modification of magnesium alloy surfaces. The resulting layers may cover surface inhomogeneities and separate the substrate surface from molecular films. This work demonstrates the feasibility and effectiveness of the concepts and techniques comprising laser or plasma based pretreatment processes or dipping procedures that involve synthetic amphiphilic polymers or biopolymers. In detail, the effects of barrier layers that have been applied by the deposition of siliceous polymer coatings in low pressure plasma processes, by laser surface treatments in controlled gas atmospheres or by dipping in liquid formulations containing a recently developed polymeric inhibitor or a mixture of the enzyme laccase and the polysaccharide maltodextrin are monitored. In this respect, a time-resolved hydrogen bubble formation test is performed, revealing interactions between water films and the modified surfaces. The surface modification is shown with X-ray photoelectron spectroscopy investigations and, in addition, the alloy surface and grain structure is characterized using energy dispersive X-ray analysis, scanning electron microscopy and scanning force microscopy. These investigations reveal that the thus established layer/substrate and layer/environment interphases differ in their composition as a result of the non-centrosymmetric layer concepts for surface functionalization applied here.

Abstract 140: Magnesium Lithospermate B Inhibits Blood Coagulation and Platelet Aggregation: Novel Mechanism of a Traditional Drug for Cardiovascular Diseases

Magnesium lithospermate B (MLB) is one of the major components of Salvia miltiorrhiza root (Danshen). Danshen extracts have been used to control cardiovascular disease for centuries. In 2005, intravenous injection of Danshen depside salt was approved in China for treatment of chronic angina. Although clinical observations have suggested that Danshen extracts inhibited thrombosis, the exact mechanism has not been adequately explored. Using an in vitro whole blood clotting assay, we observed that MLB (250 μM) significantly reduced clot size. Both the clot wet and dry weights were decreased following treatment (108.3 mg vs. 63.5 mg, and 32.8 mg vs. 18.5 mg, p&lt;0.05, respectively). Using thromboelastography, we found that MLB markedly decreased the mechanical strength of the clot and modestly delayed initiation of coagulation in cell-free blood plasma prepared by centrifugation (10,000 хg, 10 min). Under confocal microscopy, we further observed that MLB significantly reduced the density of the fibrin network formed in plasma following thrombin treatment, suggesting that MLB targets coagulation factors to inhibit coagulation. Recent network pharmacology analyses predict that MLB may interact with VWF, factor XIII (FXIII), or thrombin in the coagulation cascade. We found that MLB did not inhibit VWF-dependent platelet agglutination induced by botrocetin. ELISA revealed that MLB also did not significantly alter the binding of activated FXIII (FXIIIa) to fibrinogen. However, when native FXIII from blood plasma was used for the same assay, MLB significantly reduced the binding of FXIIIa to fibrinogen. Since generation of FXIIIa from FXIII is thrombin-dependent, these data suggest that MLB inhibits thrombin activity or thrombin generation. Indeed, we found that MLB markedly inhibited thrombin-induced gel-filtered human and mouse platelet aggregation. These data demonstrated a novel role for MLB in the inhibition of blood coagulation and platelet aggregation, likely through direct inhibition of thrombin function, although we cannot exclude its additional anti-thrombotic activities. Thus, purified MLB may represent an efficient, low-cost agent for treatment of artery and deep vein thrombosis.

Comparison between Addition of Titanium and Titanium Plus Boron to MgAZ31 on its Grain Size and its Mechanical Characteristics

Magnesium and its alloys are the lightest constructional available materials on earth with a maximum density of 1.78 g /cc and melting point of 650 ͦC, with good damping characteristics. Therefore; they are alloyed or micro alloyed with other elements. In this paper comparison between the addition of Ti and Ti+ B to this alloy on its grain size and its mechanical characteristics is investigated both in the cast and after direct extrusion and the obtained results are presented and discussed.

Fetal neuroprotective role of magnesium sulphate

Magnesium sulphate (MgSO4) is used for very long time in Oobstetrics as anticonvulsivant, antihypertensive and tocolytic and in pediatrics as anticonvulsivant, anti-anaphylactic and antispasmodic. In recent years we have found that the use of antenatal MgSO4 to women with imminence of premature birth may have fetal neuroprotective role. Babies born too early have a higher risk of dying in the first weeks of life than babies born at term, and those who survive often have damage in the form of cerebral palsy, blindness, deafness or physical disabilities. Neonatal morbidity and mortality rates attributed to prematurity, increase proportionally with the lower the gestational age is at the moment of birth. In the mid 1990s, observational studies suggests that premature infants born by mothers who received MgSO4 as tocolytic or for other obstetrical indications had a lower rate of cerebral palsy compared to children born prematurely by women who haven’t been exposed to therapy with MgSO4. The objective of this review is to analyze the results of randomized, controlled studies which investigates the neuroprotective effect of MgSO4 against to specific neurological disease of prematurity.

Analysis on Influence Factors of Greenhouse Gas Emissions of Magnesium Production Process

Magnesium is a promising lightweight and green metallic engineering material, but the environmental impact of primary magnesium production stage, especially greenhouse gas (GHG) emissions cannot be ignored. In this study, the life cycle energy consumption and GHG emissions caused by the production of primary magnesium in the years of 2003-2013 in China were calculated; the factor decomposition was conducted to analyze the GHG emissions of magnesium production process by using logarithmic mean Divisia index method (LMDI), including energy GHG emission factors, energy structure, energy consumption per ton of primary magnesium, production, emissions per unit of dolomite and ferrosilicon, and dolomite and ferrosilicon consumptions per ton of primary magnesium. The results showed that GHG emissions of primary magnesium production increased 260.29*104 t CO2eq in total from 2003 to 2013. The variety magnesium production contributed the biggest part of GHG emissions, accounting for 418.17%. The energy structure took second place on the contribution of GHG emissions, accounting for-161.49%. The nest part was energy consumption per ton of primary magnesium, accounting for-138.97%. While, the contribution of energy GHG emission factors, emissions per unit of dolomite and ferrosilicon, and dolomite and ferrosilicon consumptions per ton of primary magnesium was relatively small, which were 0.88%, 0.00% -2.72% -4.73% and-11.13%, respectively. Thus, it is the key methods to reduce GHG emissions by optimizing the energy structure and decreasing the energy consumption.

Anti-aging effect of Magnesium Lithospermate B from Salvia miltiorrhiza Bunge on skin

Magnesium lithospermate B (MLB, also called salvianolic acid B), one of the hydrophilic phenolic compounds of Salvia miltiorrhiza Bunge has been reported to possess numerous health benefits, but a role for MLB in the prevention of skin aging has not been fully explored. In a recent publication, we reported that the skin anti-aging action of MLB depends on its ability to suppress collagen degradation via its anti-oxidant activity, and subsequently, to increase the expressions of type I and III collagen genes through PPARb/d activation. For this research highlight, we describe the salient findings from our recent study on the anti-wrinkle effect of MLB and the molecular mechanism underlying its skin anti-aging action.

Has a mixture of amino acids and micronutrients influence on glucose metabolism and dietary fatty acid pattern in chronic psychosocially stressed persons? A pilot study

Brain food, e.g. L-tryptophan, antioxidative substances, B vitamins and magnesium are thought to be beneficial for obesity, inflammation and insulin resistance. In the present pilot study we hypothesised that a specific amino acid mixture with micronutrients improves the cardiometabolic situation of chronically stressed persons. Cardiovascular and metabolic parameters were analysed as per protocol in 32 patients. Chronic stress disorders in the same patients were assessed by a psychological neurological questionnaire (PNF). After dietary intervention a reduction of the fasting serum insulin concentrations occurred in the treatment group. An association was found between PNF values, insulin concentrations at baseline and an insulin reduction after 12 weeks. The results support the use of our specific dietary supplement for improved stress management and a decrease in metabolic dysfunction.

Property Oriented Wire Rolling Technology for Mg-Al Alloys

Magnesium and magnesium alloys offer high potential as lightweight materials. Current works are mainly focused on the metal forming technologies and material development for sheet and strips to provide magnesium flat products for industrial applications. However, the technology for the production of magnesium long products for fasteners or other connecting elements is exclusive the extrusion process. A cost-efficient alternative can be the caliber rolling technology for magnesium rods and wire with regard to refined microstructure and specific required properties. But this whole process is rarely applied up to now and all material-specific as well as deformation relevant basics must be developed and additionally validated under industrial conditions. This paper gives the overview for a magnesium-specific wire rolling technology under consideration of chemical composition (AZ31, AZ61, AZ80) and their influence to final mechanical properties in correlation with the microstructure evolution along the whole process line. Therefore, the process-and material-dependent microstructural evolution during rolling process was investigated. The structural constitution is detailed by the grain size and the precipitation conditions. For the determination of the mechanical properties hardness measurement as well as tensile testing was carried out. To preliminary design and determine the material flow, the temperature distribution, and the logarithmic strain, a commercial numerical simulation tool was applied on base of the implemented material-specific deformation and recrystallization behavior. Hence, it was possible to design a magnesium specific caliber sequence for the production of fine-grained magnesium wires with Ø 8 mm and excellent mechanical properties.