Abstract Magnesium Research Articles

Alendronate-loaded gelatin microparticles as templating agents for macroporous magnesium phosphate-based bone cements

Magnesium phosphate-based cements (MPCs) have recently attracted great attention as materials for bone repair. However, the lack of macroporosity, fundamental for cells permeation and bone ingrowth, is one of the main limitations hampering MPCs full exploitation. In this work gelatin microparticles are exploited as templating agents for the creation of macroporosities in MPCs. In addition, gelatin particles were loaded with a well-recognized drug for the treatment of osteoporosis, alendronate, to locally release the therapeutic agent. Gelatin microparticles of different size were prepared with a simple water-in-oil emulsion method and included in MPCs at various concentrations. The properties of both the MPCs and the final material were characterized by assessing the composite in terms of injectability, setting time, infrared spectroscopy, scanning electron microscopy and confocal Raman microscopy. The MPC-gelatin composites were then incubated in water at physiological temperature, to promote the dissolution of the gelatin, obtain a macroporous cement, and release gelatin and alendronate. The obtained results show that gelatin microparticles have a twofold action as they allow for the formation of MPC with an interconnected and hundreds of µm-sized porosity and the local release of alendronate, resulting in a material with ideal features for bone repair.Graphical abstract

Magnesium metabolism and its assessment

Magnesium is the fourth most abundant cation in the body. It has several functions in the human body including its role as a cofactor for more than 300 enzymatic reactions. Magnesium balance in the body is controlled by a dynamic interplay among intestinal absorption, exchange with bone, and renal excretion. Intestinal magnesium absorption proceeds in both a passive paracellular and an active transcellular manner. Regulation of serum magnesium concentrations is achieved mainly by control of renal magnesium reabsorption. In the kidney passive paracellular transport via claudins facilitates bulk magnesium absorption, whereas active transcellular pathways mediate the fine-tuning of magnesium absorption. There are no readily available and easy methods to assess magnesium status. Serum magnesium and the magnesium tolerance test are the most widely used. Measurement of ionized magnesium may become more widely available with the development of ion selective electrode analyzers.​

<i>In Vitro</i> Corrosion Study of Selected Laser Melted WE43 Magnesium Alloy in Hank ́s Balanced Salt Solution

Magnesium (Mg) and its alloys have been intensively investigated as potential biocompatible materials with appropriate structural, mechanical and corrosion properties for preferable orthopedic applications. Selective Laser Melting (SLM) technique was developed for the fabrication of three-dimensional components with high structural integrity at a low cost and is compatible with various materials, including biocompatible magnesium alloys. In this study, WE43 magnesium alloy samples produced by SLM technique were examined by in vitro static test in Hank's balanced salt solution (HBSS) under physiological temperature conditions for six days. A hydrogen evolution method for the estimation of the corrosion rate was used. The phase composition of samples before and after the immersion test was investigated by X-ray diffraction (XRD). The surface morphology and chemical composition of the initial material and tested samples were characterized by scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDX).

Strain Rate and Temperature Effects on Formability and Microstructure of AZ31B Magnesium Alloy Sheet

Magnesium alloys play an important role in lightweight structures, which are extensively used in different industries due to their excellent mechanical and physical properties. In this paper, the formability of the AZ31B magnesium alloy sheet was studied by using tensile tests at different temperatures (from 25 to 250 °C) and strain rates (from 0.017 s−1 to 0.34 s−1). The results showed that the material behaves with positive temperature sensitivity when forming at a temperature lower than 200 °C. The effect of the strain rates on the formability of AZ31B was larger at high temperatures. The metallography of AZ31B at different temperatures and strain rates was observed by OM. The results showed that the partially recrystallized structure was exhibited at a temperature of 150 °C. With the increase in temperature, the approximate complete recrystallization was exhibited at a temperature of 250 °C. The fracture morphology of AZ31B was observed at different strain rates and temperatures by SEM. Additionally, the main fracture pattern was quasi-cleavage at room temperature. However, with the increase in temperature, the fracture pattern was transited from a quasi-cleavage pattern to a ductile fracture pattern. The ductile fracture pattern was the main fracture pattern at a temperature of 250 °C.

Metallo-phthalocyanines containing triazole substituents: Synthesis, spectroscopic and photophysicochemical properties

Magnesium(II) (4), lead(II) (5) and zinc(II) (6) phthalocyanines were prepared. The structures of 4–6 were confirmed by the spectroscopic characterization such as FT-IR, 1H-NMR, MALDI-TOF mass, UV-vis and fluorescence spectral data. The aggregation behavior of the triazole substituted phthalocyanines (4–6) was investigated in different solvents and no aggregation was observed. The photophysicochemical properties of 4–6 were investigated in DMSO. The photophysical and photochemical behaviors varied depending on the type of metal in the center of phthalocyanine. The zinc(II) phthalocyanine 6 showed the highest singlet oxygen quantum yield and the highest photostability. The magnesium(II) phthalocyanine 4 exhibited the highest fluorescence quantum yield. The zinc(II) phthalocyanine 6 has good photosensitizer performance due to its high singlet oxygen generation ability, high photostability and formation of non-aggregated species.

An additively manufactured magnesium-aluminium alloy withstands seawater corrosion

Magnesium, the lightest structural metal, has inherently poor corrosion resistance. In this study, we developed a magnesium-aluminium Mg-10.6Al-0.6Zn-0.3Mn alloy, additively manufactured by laser powder bed fusion. We reveal that this alloy has a record low degradation rate amongst all magnesium alloys in practically relevant corrosive solutions, and it even withstands seawater corrosion. As tested by a number of methods, the alloy shows even more enhanced passivation with longer immersion periods. The alloy surface following immersion maintained a nearly corrosion-free appearance and was determined to have a thin aluminium-containing surface film, due to surface enrichment of aluminium from the supersaturated matrix. Aluminium enrichment near the sample surface was also observed when the sample is immersed in phosphoric acid or exposed to atmosphere at room temperature. This study demonstrates the prospects for additively manufactured ultra-lightweight magnesium structure with outstanding corrosion resistance.

Effect of potassium and magnesium application on growth, yield and nutrient uptake of rainfed maize in the sub-montaneous region of Punjab, India

Potassium (K) and magnesium (Mg) are essential plant macronutrients responsible for mitigation of biotic and abiotic stresses as well as enhancement in yield of maize. In rainfed maize, low productivity due to imbalanced use of fertilizers, erratic rainfall and periodic dry spells are major constraints. Hence, a field experiment was conducted in rainy season during 2015, 2016 and 2017 on an Inceptisol to optimize the levels of K and Mg in rainfed maize. The experiment consisted of four levels of K; control, K @20 kg ha−1, K@30 kg ha−1 and K 40 kg ha−1 and four levels of Mg; control, Mg@15 kg ha−1, Mg@30 kg ha−1, and Mg@45 kg ha−1. Application of K and Mg improved leaf area Index, chlorophyll content and relative water content in maize. Yield attributes of maize also improved significantly with application of K and Mg over control. Highest grain yield (3205 and 3169 kg ha−1) was recorded with the application of 40 kg K ha−1and 45 kg Mg ha−1, respectively which was at par with 30 kg K ha−1 (3103 kg ha−1) and 30 kg Mg ha−1 (3106 kg ha−1), respectively. The highest net returns (US $347 ha−1) and BC ratio (1.72) was recorded with 40 kg K ha−1 while application of 30 kg Mg ha−1 recorded highest net returns (US $332 ha−1) and BC ratio (1.71). Application of 30 kg K ha−1 and 30 kg Mg ha−1 was found to be optimum to improve growth, yield and nutrient uptake in rainfed maize.

Magnesium in aging and aging-related disease

Magnesium (Mg2+) is an essential divalent cation in human body. Its balance is tightly controlled via a balanced interplay among intestinal absorption, storage, and renal excretion, involving multiple transporters across cell membrane that regulate Mg2+ influx and efflux. Mg2+ is involved in a variety of physiological and pathological processes such as enzymatic reactions, energy metabolism, cell proliferation, apoptosis, oxidative stress, and inflammation. In particular, Mg2+ contributes to the molecular hallmarks of aging. Emerging evidence demonstrates that altered Mg2+ status has been associated with many aging-related diseases, including cancer, cardiovascular disease, neurodegenerative disease, musculoskeletal function, metabolic syndrome, and COVID-19. In this review, we focus on Mg2+ and its association with molecular hallmarks of aging. We also summarize recent findings supporting an important role of Mg2+ in aging-related disease including the COVID-19 pandemic.

Strategies to Control In Vitro Degradation of Mg Scaffolds Processed by Powder Metallurgy

Magnesium scaffolds are biodegradable, biocompatible, bioactive porous scaffolds, which find applications within tissue engineering. The presence of porosity increases surface area and enhances cell proliferation and tissue ingrowth. These characteristics make Mg scaffolds key materials to enhance the healing processes of tissues such as cartilage and bone. However, along with the increment of porosity, the corrosion of magnesium within a physiological environment occurs faster. It is, therefore, necessary to control the degradation rate of Mg scaffolds in order to maintain their mechanical properties during the healing process. Several studies have been performed to increase Mg scaffolds’ corrosion resistance. The different approaches include the modification of the Mg surface by conversion coatings or deposited coatings. The nature of the coatings varies from ceramics such as hydroxyapatite and calcium phosphates to polymers such as polycaprolactone or gelatin. In this work, we propose a novel approach to generating a protective bilayer coating on the Mg scaffold surface composed of a first layer of naturally occurring Mg corrosion products (hydroxide and phosphates) and a second layer of a homogeneous and biocompatible coating of polylactic acid. The Mg scaffolds were fabricated from Mg powder by means of powder metallurgy using ammonium bicarbonate as a space holder. The size and amount of porosity were controlled using different size distributions of space holders. We addressed the influence of scaffold pore size on the conversion and deposition processes and how the coating process influences the in vitro degradation of the scaffolds.

Prospective of Magnesium and Alloy-based Composites for Lightweight Railway Rolling Stocks

Magnesium and its alloy have superior characteristics and matches to great potential in railway rolling stocks. The low density and high strength make it ideal for lightweight applications, exceptionally for car bodies and rolling stocks. In this study, a comprehensive review has been carried out on magnesium alloy towards its prospective in railroad vehicles, emphasizing fatigue damage, vibration, energy savings, and overcoming wear or friction loss. Furthermore, with better stiffness and strength, the weight reduction contributes to the better energy and fuel-saving for low-speed trains than bullet and high-speed trains. However, the potential application of magnesium and its alloy has a colossal study gap in the railway industry's processing, fabrication, and maintenance that needs further studies and research.

Extraction of Magnesium and Nickel from Nickel-Rich Serpentine with Sulfation Roasting and Water Leaching

Magnesium and nickel were recovered from nickel-rich serpentine through sulfation roasting and water leaching. The factors affecting the extraction percentages of Mg and Ni were discussed. Under the conditions of the ratio of acid to ore of 0.8:1 and roasting temperature of 650 °C for 120 min, 91.6% of Mg and 88.7% of Ni but only 4.8% of Fe were extracted. The roasting kinetics of Mg and Ni were investigated. The results showed that the roasting stage was governed by internal diffusion in the temperature range of 350–650 °C, and the activation energy of nickel and magnesium were different in the time ranges of 0–30 min and 60–120 min, with 17.45 kJ⋅mol−1 (0–30 min) and 14.12 kJ⋅mol−1 (60–120 min) for magnesium and 15.48 kJ⋅mol−1 (0–30 min) and 12.46 kJ⋅mol−1 (60–120 min) for nickel. The kinetic equations were obtained.

ЭЛЕКТРОЛИТИЧЕСКОЕ ПОЛУЧЕНИЕ МАГНИЕВЫХ ПОКРЫТИЙ

Magnesium, its compounds, and alloys arise recently the heightened interest among scientists all over the world. The interest in magnesium research is caused by its combination of many promising properties that find practical application in various sectors of the national economy. On an industrial scale, the bulk of magnesium is produced by the electrolysis from the melt. However, there is a problem with the environmental security of this process. This method is environmentally unfriendly since it is accompanied by the release of hazardous chlorine and organochlorine compounds into the environment. In some cases, the electrodeposition from solutions may serve as an alternative. The task to produce magnesium and magnesium-containing coatings using electrodeposition from solutions was already raised, but it is not yet possible to obtain a stable electrolyte that allows obtaining high-quality coatings. The authors propose an electrolyte in which isopropyl alcohol is used as a solvent. Magnesium-containing coatings were produced by electrodeposition on a conductive base. The authors prepared an electrolyte based on anhydrous magnesium sulfate. To increase the conductivity of the electrolyte, sodium, potassium, and calcium chlorides in different concentrations were added to the solution. The authors carried out the experimental studies of the effect of the electrolyte composition and electrodeposition modes on the morphology and elemental composition of magnesium-containing coatings. Electron microscopic studies and the studies of the elemental composition of samples by the energy-dispersive X-ray fluorescence spectrometer show that the non-stationary (two-step) electrodeposition mode is the optimal one for producing magnesium coatings with a fine crystalline structure, low porosity, and high magnesium content.

Mechanical behavior of graphene magnesium matrix composites based on molecular dynamics simulation

Magnesium alloy is regarded as a lightest engineering structural metal material due to its low density, but its wide application is limited due to poor plastic deformation behavior. Therefore, the comprehensive mechanical properties of enhanced magnesium alloy have become a research focus in the material science. Here, the effect of graphene on the deformation behavior and that on the mechanical properties of magnesium under tensile loading are studied by molecular dynamics simulation. The results show that the introduction of graphene can significantly improve the mechanical properties of pure magnesium. Comparing with pure magnesium, the Young's modulus and the first peak stress of the graphene magnesium matrix (GR/Mg) composites are increased by about 27.5% and 36.5% respectively, which is mainly due to the excellent mechanical properties of graphene. The results also indicate that the embedded position of graphene has little effect on the Young's modulus or peak stress of the GR/Mg composites, but it will significantly affect the plastic deformation behavior of the GR/Mg composites after the second peak stress. With the increase of the embedded height of graphene, the average flow stress of the GR/Mg composites first increases in the later stage of plastic deformation. When the embedded height reaches 0.4<i>L</i>, the average flow stress of the GR/Mg composites reaches a maximum value, and then decreases. This phenomenon of the Gr/Mg composites can be explained by the plastic deformation behavior of the magnesium matrix above and below graphene. The embedded position of graphene has a great influence on the plastic deformation behavior of the upper and lower magnesium matrix of the GR/Mg composites. When the embedded height of graphene is small, the plastic deformation capability of magnesium matrix under graphene is strong and dislocation slip is easy to occur. And when the embedded height of graphene is large, the plastic deformation capabilities of the two parts of magnesium matrix above and below graphene are equal, and their plastic deformation behavior tends to be synchronous. The results show that the plastic deformation behavior of the GR/Mg composite is the same as that of pure magnesium, and the phase transition from HCP to BCC and then to HCP occurs in the process of the plastic deformation. The phase transition mechanism of magnesium matrix is also analyzed in detail. The results of this study have certain theoretical guiding significance in designing the high performance graphene metal matrix composites.

Magnesium–Magnetic Field Synergy Enhances Mouse Bone Marrow Mesenchymal Stem Cell Differentiation into Osteoblasts Via the MAGT1 Channel

Magnesium ion (Mg2+)‐based materials are known to exert osteogenic effects that can be enhanced by the bioelectrical properties of magnetic fields. In this study, we examined the effect of a medium‐strength static magnetic field (SMF), combined with a Mg2+‐containing medium, on the proliferation and osteogenic differentiation of mouse bone marrow mesenchymal stem cells (BMSCs). Mouse BMSCs were divided into a control group, 7.5 mM Mg2+ group, 15 mT SMF group, and 7.5 mM Mg2+ plus 15 mT SMF group. Osteoblast proliferation was measured using a Cell Counting Kit‐8 assay, whereas osteogenic differentiation was detected using alkaline phosphatase (ALP) staining and western blot analysis, respectively. The number and size of calcium nodules were determined using Alizarin Red staining. Compared with those in the control group, the ALP activity, calcium nodule formation, and osteogenic protein expression were promoted in other groups. In particular, Mg2+‐SMF had a significant effect after 7 days of intervention and more effectively promoted BMSC differentiation and proliferation than either Mg2+ or the SMF alone, suggesting that Mg2+‐SMF synergistically contributed to osteogenic differentiation and cell proliferation. To examine their roles in bone differentiation, the Magt1 and Creb1 genes were silenced in BMSCs, and the findings indicated that the synergistic intervention with Mg2+ and magnetic fields might exert osteogenic effects via the MAGT1 channel and CREB1 protein. This study provides an experimental basis for a potential Mg2+‐SMF synergistic artificial bone material that could be clinically applied in the treatment of bone defects.

Research status and prospect of dissimilar light alloy welding technology

Magnesium alloys, aluminum alloys and titanium alloys are currently widely used light alloy materials with good prospects. The welding of Mg/Al/Ti dissimilar light alloys has a wide range of application requirements in aerospace, automobile manufacturing, electronic information and other fields, and is a hot topic of current research. This article summarizes the welding research results of Mg/Al/Ti dissimilar light alloys in recent years, outlines the current research status of welding technology of Mg/Al/Ti dissimilar light alloys, analyzes the common problems and solutions in welding, and proposes further Carry out the research of Mg/Al/Ti welding technology and basic theory, look forward to the effective ways to improve the welding performance of Mg/Al/Ti dissimilar light alloys and future research directions, and promote the promotion of Mg/Al/Ti dissimilar light alloy joints The practicality of it is of great significance.

Synthesis and Characterization Studies of Pure MgO by Sol-Gel Method

Magnesium oxide nanoparticles were synthesized by Sol-gel Method. The synthesized nanoparticles were characterized by Powder XRD, UV-VIS, SEM and EDAX. The XRD studies of the sample confirmed the formation of cubic structure and the particle size and lattice constants were analyzed. SEM results show Spherical shape for MgO. A broad absorbance band from UV-Vis spectra is located at around 2.32eV. EDAX is used to analyze the functional groups of synthesized nanoparticles. This is the simple synthesis method and they are used in optical and gas sensor applications, telecommunication cables, conductor wires, connector wires and automotive switches.

The influence of friction stir welding tool shape on quality of AZ31 Magnesium welding product

Magnesium is one type of material that can be used as a base metal in welding. Magnesium has superior properties, including low density, good ductility, medium strength and excellent corrosion resistance. Because of its properties, the metal is widely used, ranging from household goods to aircraft components. These base metals are categorised as mild when viewed from the specific gravity of magnesium (1.74 g/cm3 and 1.83 g/cm3). Welding is the process of merging two or more base metals which are merged at the contact surface with or without additives or fillers. Welding is divided into two main categories, Liquid and Solid-State Welding. Friction Stir Welding (FSW) is an example of Solid-State Welding (Non-Fusion Welding). FSW is a friction welding process that twists the tool by utilising heat energy and pressing without additives or fillers until the base metal is in a phase change. The welding process in this study used the cone and spiral shape with a tool rotation at 2000 rpm and a welding speed of 16 mm/min. The tests carried out are tensile and hardness testing. This study found that the tool shape, tool rotation, and welding speed significantly affect the mechanical properties of the welded AZ31 magnesium. The spiral shape will make the welding area wider. Although the cone shape will have a small area, the weld will look perfect with good tensile strength, while the hardness values for the two tool shapes are almost the same, but the cone shape is better.

Nebulized Magnesium Sulphate vs Normal Saline as an Adjunct in Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Magnesium revealed to have properties of bronchodilation in chronic obstructive pulmonary disease (COPD) and asthma. A clinical benefit of nebulization with magnesium has been observed in asthma. The aim of the analysis was the therapeutic benefits comparison of using magnesium sulphate in nebulized form as an adjuvant of the normal saline solution among patients with exacerbations of COPD. Study Design: A randomized single blind interventional study. Place and Duration: In the Department of Medicine, Islam Medical College and Teaching Hospital Sialkot for six months duration from March 2021 to September 2021 Methods: This study involved 132 cases of acute COPD exacerbations with PEFR <300 L / min, evaluated twenty mints after initial therapy. Patients were administered salbutamol 5mg mixed with 3 ml of saline or 3 ml of isotonic magnesium sulphate three times at thirty-minute intervals using a nebulizer. At 90 minutes: Primary outcome of PEFR were measured and admission to hospital, invasive or non-invasive ventilation along with mortality were measured as 2ndry outcomes. Results: After nebulization with magnesium sulphate, the mean PEFR was 86.3 ± 11.9 l / min, 97.6 ± 19.1 l / min and 99.6 ± 15.2 l / min and 79.17 ± 14.11 l / min, 90.17 ± 18.27 l / min, and 93.17. ± 20.63 L. Statistically significant differences were found in the normal saline group at thirty, sixty and ninety minutes, correspondingly. In the magnesium group, 91.9% were admitted to the ward, 8.1% to the intensive care unit, 81.7% to the ward, and 18.3% to the salt group to the intensive care unit. The differences in ventilation and mortality were negligible. Conclusions: In the context of AECOPD, nebulized magnesium sulphate in combination with salbutamol has a therapeutic advantage over PEFR, but has no effect on hospitalization, the need for mortality and non-invasive or invasive ventilation. Keywords: Peak expiratory flow, magnesium sulphate and chronic obstructive pulmonary disease.

Unraveling Mg 〈c + a〉 slip using neural network potential

ABSTRACT Magnesium (Mg) activates 〈c + a〉 dislocation slip on the second order pyramidal slip plane. This slip mode is very complex compared to other modes including several metastable structures. Due to the complexity and very similar energies of the different structures, reliably modelling this slip mode is challenging. The problem is exacerbated when considering alloying, in which a combination of 1st order and 2nd order pyramidal slip is usually observed. Motivated by the need for a high fidelity potential for Mg alloys, we have developed first a highly accuracy potential for pure Mg. The new potential shows better agreement with density functional theory and experimental calculations than previous interatomic potentials for Mg. With the help of this new potential, we demonstrate that the basal dissociated 〈c + a〉 core is not sessile, as previously thought, and that constant stress molecular dynamics demonstrate clear preference for the 2nd order pyramidal system over the 1st order system.

Preliminary Studies for One-Step Fabrication of Metallic Iron-Based Coatings on Magnesium as Temporary Protection in Biodegradable Medical Application

Iron and magnesium are being considered as promising candidates for biodegradable materials in medical applications, both materials having their specific advantages and challenges. A hybrid of metallic iron and magnesium in a layered composite is studied in the present work, to combine the merits of both metals. A single-step dip-coating method was employed to prepare the layered composite material. Morphology, composition, crystal structure and corrosion behavior of the Mg/Fe sheet were assessed by SEM, EDX, XRD, and electrochemical measurements. The Mg/Fe layered composite sheet is composed of the magnesium substrate, a 1–2 µm metallic iron coating, and a pompon-like Mg(OH)2/MgO top layer. Long-term open-circuit potential measurements revealed that the Mg/Fe sheet samples exhibit a “self-healing” effect in Dulbecco’s modified Eagle’s medium.