Increase In Magnesium Concentration Research Articles

Influence of Magnesium Ion Binding on the Adenosine Diphosphate Structure and Dynamics, Investigated by 31P NMR and Molecular Dynamics Simulations.

Magnesium (Mg2+) is the most abundant divalent cation in the cell and is essential to nearly every biochemical reaction involving adenosine triphosphate (ATP) and its lower energy counterpart, adenosine diphosphate (ADP). In this work, we examine the solution dynamics of ADP at different concentrations and record the changes thereof due to the presence of Mg2+ ions. Relaxation and diffusion experiments were performed on a range of ADP solutions with increasing magnesium concentration. The most significant changes of both relaxation and diffusion behaviors are observed when adding Mg2+ up to 0.5 ADP equivalent (eq), with most of the changes complete at 1 eq. Molecular dynamics simulations also show a significant structure introduced by Mg2+ with very stable pyramidal coordination with the phosphate oxygens. A more extended structure found in the presence of Mg2+ is consistent with the experimental slowing of diffusion and an increase in the spin-lattice relaxation rate. We do not observe direct evidence of aggregation in solution, although translational diffusion is slowed down significantly at higher concentrations (while solvent diffusion remains constant).

Citrate-Buffered, Magnesium-Enriched Dialysate on Calcification Propensity in Hemodialysis Patients – The CitMag Study

IntroductionSerum calcification propensity (T50 time) is associated with mortality in dialysis patients. Several solitary interventions improve T50, but whether a combination of interventions yields further increases in T50 is unknown. We hypothesized that a combination of two interventions, namely increasing magnesium concentration while simultaneously substituting acetate for citrate in the dialysis fluid, leads to increases in T50 values. MethodsIn a randomized, controlled trial, 60 chronic hemodialysis patients were allocated to either continue on standard (S) dialysate (3 mmol/l acetate, 0.5 mmol/l magnesium) or a sequence of magnesium-enriched (Mg0.75) dialysate (3 mmol/l acetate, 0.75 mmol/l magnesium) for 2 weeks followed by combination treatment using citrate-buffered, magnesium-enriched (Cit+Mg0.75) dialysate (1 mmol/l citrate, 0.75 mmol/l magnesium) for 3 weeks. The primary endpoint was the difference in T50 times between the S group and the Cit+Mg0.75 group. ResultsThere was no significant difference in T50 time between the S group compared to the Cit+Mg0.75 group (236 ± 77 vs. 265 ± 97 minutes, p=0.23). The size of secondary calciprotein particles (CPP-2Rh) did not differ between the S group and the Cit+Mg0.75 group (294 ± 95 vs. 309 ± 91 nm, p=0.56). In longitudinal analyses, serum magnesium concentrations increased from 1.07 ± 0.17 to 1.24 ± 0.17 mmol/l with the Mg0.75 dialysate (p<0.0001) but decreased again to 1.19 ± 0.16 mmol/l with the Cit+Mg0.75 dialysate (p<0.0001). ConclusionThe combination of citrate-buffer with increased magnesium concentration in dialysate does not improve T50.

Development of BSCMF system of cathode materials and fabrication of symmetrical cell (BSCMF/GDC/BSCMF) for low temperature solid oxide fuel cell applications

ABSTRACT In the present work, cathode materials of Ba0.5Sr0.5(Co1-xMgx)0.2Fe0.8O3 system (x = 0, 0.2, 0.4, 0.6, 0.8, 1) have been produced and the effect of magnesium (Mg) doping level on cathode performance with Gadolinium doped Cerium (GDC) electrolyte was investigated. The polarisation resistance (RP) for cathode symmetric cells was measured from 600°C to 700°C under open circuit state. At 700 °C, the polarisation resistance of BSCF is 13.96 ohm-cm2 and with the addition of Mg it has decreased to 5.17 ohm-cm2. Further increase in the Mg concentration decreased the polarisation resistance up to 0.34 ohm-cm2, which is the minimum value obtained in the composition BSCMF8. It is observed that charge transfer (CT) is more in the case of Mg-rich compositions. With the increase of magnesium concentration in the cathode, RP value was observed as decreased. This is due to the high oxygen permeation flux behaviour of magnesium, which is in the B-site of the cathode. The coefficient of thermal expansion (CTE) of BSCF is measured to be 22.1 × 10−6/K and decreased to 17.45 × 10−6/K with Mg addition in the composition to BSCMF8, due to the constant oxidation state of Mg by which it suppressed the chemical expansion caused by Co.

Reconstituted TAD-size chromatin fibers feature heterogeneous nucleosome clusters

Large topologically associated domains (TADs) contain irregularly spaced nucleosome clutches, and interactions between such clutches are thought to aid the compaction of these domains. Here, we reconstituted TAD-sized chromatin fibers containing hundreds of nucleosomes on native source human and lambda-phage DNA and compared their mechanical properties at the single-molecule level with shorter ‘601’ arrays with various nucleosome repeat lengths. Fluorescent imaging showed increased compaction upon saturation of the DNA with histones and increasing magnesium concentration. Nucleosome clusters and their structural fluctuations were visualized in confined nanochannels. Force spectroscopy revealed not only similar mechanical properties of the TAD-sized fibers as shorter fibers but also large rupture events, consistent with breaking the interactions between distant clutches of nucleosomes. Though the arrays of native human DNA, lambda-phage and ‘601’ DNA featured minor differences in reconstitution yield and nucleosome stability, the fibers’ global structural and mechanical properties were similar, including the interactions between nucleosome clutches. These single-molecule experiments quantify the mechanical forces that stabilize large TAD-sized chromatin domains consisting of disordered, dynamically interacting nucleosome clutches and their effect on the condensation of large chromatin domains.

Evaluation of the complex approach effectiveness of atrophic colpitis treatment in menopausal aged women from the pathogenetic view

Objectives: to determine the status of connective tissue and ionized magnesium value before and after complex treatment of atrophic colpitis with the CO2 laser in menopausal women. Materials and methods. 160 women with atrophic colpitis took part in this prospective study and were divided into three groups depending on the therapy. The main group included 55 patients who underwent CO2 laser therapy. The comparison group included 40 women who underwent CO2 laser therapy and local hormonal treatment with suppositories containing estriol and magnesium saturation by magnesium lactate dihydrate. The control group consisted of 65 women who received only suppositories containing estriol. The duration of treatment was 12 months. In addition to general clinical studies, markers of collagen synthesis (Total PINP, Total PІІІNP), collagen resorption marker (Pyriliks-D), as well as the ionized magnesium value in blood serum were determined in all patients.Results. A significant increase and steady retention at the physiological level of the average value of the Total PINP in the comparison group was revealed. The average level of the Total PIІІNP in patients of this group underwent a significant decrease and remained steadily at the upper limit of the physiological norm. A significant decrease and stable retention at the physiological level of the Pyriliks-D was noted in the comparison group against the background of the proposed therapy. Correction of magnesium status in the comparison group leads to a reliable and stable increase in the Mg+ ions concentration in blood serum.Conclusions. The inclusion CO2 laser in combination with local hormonal therapy and long-term correction of mineral metabolism in the treatment of the comparison group led to the stable normalization and prolonged retention at the physiological level for 12 months of the procollagen type I N-terminal propeptide, procollagen type III N-terminal propeptide, collagen resorption marker Pyriliks-D and a significant increase in magnesium concentration. This is confirms the effectiveness of the proposed complex.

Extreme halophilic bacteria promote the surface dolomitization of calcite crystals in solutions with various magnesium concentrations

In this study, we conducted experiments on the transformation from calcite to protodolomite using bacteria. The surface dolomitization of calcite seed crystals was initiated by Vibrio harveyi J4, a newly isolated extreme halophilic bacterium, under increasing magnesium concentrations of 0, 0.05, 0.10, 0.15, to 0.20 mol L–1. The mineralogy, surface morphology, elemental composition, and lattice structure of the calcite crystals before and after bacterial treatment were analyzed by XRD, SEM-EDS, AFM and TEM, respectively. Organic functional groups within newly-formed minerals were determined by FTIR and XPS. The weight loss of minerals in the experimental group and control groups was measured by TGA and DSC. The experiments resulted in numerous nano-spheroidal-hemispheroidal precipitates being formed on the surface of the calcite seeds, whereas dissolution took place on the calcite crystal surfaces in control experiments with no bacteria. The nano-spheroids-hemispheroids were confirmed to be disordered protodolomite. The number of protodolomite spheroids on the calcite crystal surfaces increases dramatically with increasing concentration of magnesium. Since no calcium ions were added to the bioreactor, the protodolomite nano-spheroids-hemispheroids are considered to have been formed through some dissolution of the calcite to provide the Ca2+ ions in a local precipitation process. The mechanism of protodolomite precipitation is thought to be related to the presence of acidic amino acids and polysaccharides in the EPS of the extreme halophilic bacteria. These results suggest that in addition to promoting the precipitation of dolomite, micro-organisms may also play a key role in the dolomitization of calcite.

Drinking water magnesium and cardiovascular mortality: A cohort study in Denmark, 2005-2016.

Cardiovascular diseases are globally a major cause of death. Magnesium deficiency is associated with several diseases including cardiovascular diseases. To examine if a low concentration of magnesium in drinking water is associated with increased cardiovascular mortality and mortality due to acute myocardial infarction and stroke. A nationwide population-based cohort study using national health registries was used. A total of 4,274,132 individuals aged 30years or more were included. Magnesium concentration in drinking water was estimated by linkage of residential addresses in the period 2005-2016 with the national drinking water quality monitoring database. The association between magnesium concentration in drinking water and cardiovascular mortality and mortality due to acute myocardial infarction and stroke was examined using a Poisson regression of number of deaths and logarithmic transformation of follow-up time as offset. The incidence rate ratio (IRR) was adjusted for differences in age, sex, calendar year, cohabitation, country of origin, and socioeconomic status. Median magnesium concentration in drinking water at inclusion was 12.4mg/L (range: 1.37-54.2mg/L). The adjusted IRR for cardiovascular mortality was 0.96 (95% CI: 0.94; 0.97) for the lowest magnesium quintile (<6.5mg/L) as compared to the highest magnesium quintile (>21.9mg/L). The adjusted IRR for mortality due to acute myocardial infarction and stroke was 1.22 (1.17; 1.27) and 0.96 (0.93; 0.99), respectively, for the lowest magnesium quintile as compared to the highest quintile A decreasing mortality due to acute myocardial infarction was seen with an increasing magnesium concentration in a dose-response manner. Low concentrations of magnesium in drinking water were associated with an increased mortality due to acute myocardial infarction. Low concentrations of magnesium in drinking water were associated with decreased cardiovascular mortality, and mortality due to stroke.

The activity of specific hypophosphatasia-causing TNSALP mutants can be improved by increasing magnesium concentration

The activity of specific hypophosphatasia-causing TNSALP mutants can be improved by increasing magnesium concentration

Influence of physical load of maximum aerobic power on hemodynamics and morpho-biochemical changes in erythrocytes in female volleyball players

Purpose: to study the types of cardiohemodynamic response of the organism and morpho-biochemical changes of erythrocytes of peripheral blood of volleyball players to physical activity of maximum aerobic capacity.&#x0D; Material and methods In 18 highly qualified volleyball players aged 22.0±0.60 years, cardiohemodynamics (by functional methods), functional changes (by biochemical methods) and the structure of erythrocytes (using scanning electron microscopy) were studied before and after the maximum (3.5 W/kg of body weight) of physical activity.&#x0D; Results. It was found that maximal physical activity causes significant changes in cardiohemodynamics, which result in morphological rearrangement of peripheral blood erythrocytes (increase in erythrocyte deformation index) and closely correlate with biochemical changes (decrease in ATP concentration and increase in magnesium concentration in erythrocytes). Possible mechanisms of realization of features of reaction of an organism of volleyball players to physical activity of the maximum aerobic power depending on type of regulation of blood circulation and morpho-biochemical changes of erythrocytes of peripheral blood are discussed.&#x0D; Conclusions. Physical activity of maximum aerobic power in highly qualified female volleyball players reveals the typological features of the cardiohemodynamic response of the body of volleyball players, which is expressed by conformational changes in peripheral blood erythrocytes and depends on the concentration of individual macroelements in these cells and on the type of cardiohemodynamics.

Dynamic RNA Fitness Landscapes of a Group I Ribozyme during Changes to the Experimental Environment.

Fitness landscapes of protein and RNA molecules can be studied experimentally using high-throughput techniques to measure the functional effects of numerous combinations of mutations. The rugged topography of these molecular fitness landscapes is important for understanding and predicting natural and experimental evolution. Mutational effects are also dependent upon environmental conditions, but the effects of environmental changes on fitness landscapes remains poorly understood. Here, we investigate the changes to the fitness landscape of a catalytic RNA molecule while changing a single environmental variable that is critical for RNA structure and function. Using high-throughput sequencing of in vitro selections, we mapped a fitness landscape of the Azoarcus group I ribozyme under eight different concentrations of magnesium ions (1–48 mM MgCl2). The data revealed the magnesium dependence of 16,384 mutational neighbors, and from this, we investigated the magnesium induced changes to the topography of the fitness landscape. The results showed that increasing magnesium concentration improved the relative fitness of sequences at higher mutational distances while also reducing the ruggedness of the mutational trajectories on the landscape. As a result, as magnesium concentration was increased, simulated populations evolved toward higher fitness faster. Curve-fitting of the magnesium dependence of individual ribozymes demonstrated that deep sequencing of in vitro reactions can be used to evaluate the structural stability of thousands of sequences in parallel. Overall, the results highlight how environmental changes that stabilize structures can also alter the ruggedness of fitness landscapes and alter evolutionary processes.

Влияние поливитаминного комплекса на биохимические аспекты показателей крови цыплят-бройлеров

The article presents the results of a study of the influence of the multivitamin complex «Nitamin » on the biochemical aspects of blood parameters in broiler chickens. It was found that the introduction of this drug in addition to the basic diet of broiler chickens led to the intensification of protein metabolism, the concentration of total protein in the blood of the birds of the experimental group was higher than in the control by 19,6%. In addition, the introduction of the drug «Nitamin» into the diet of birds caused an increase in blood glucose in broiler chickens by 17,4%, a decrease in cholesterol in blood serum by an average of 8,9%, a tendency to increase uric acid in the blood by 58,6%, increase in magnesium concentration by 5,5% and pH level by 0,06 units. pH. In relation to the control group, the iron content in the blood of the birds of the experimental group increased by 18%, which indicates a better assimilation of the microelement by the body from the feed and the stimulating effect of the study drug on the intensity of mineral metabolism in general.

Anxiolytic effect of chronic intake of supplemental magnesium chloride in rat

Evidence suggest that magnesium dietary supplementation has several health benefits including lowering blood pressure, reducing insulin resistance, and improving symptoms of depression, anxiety, and migraine. Here, we aimed to study the effect of chronic magnesium supplementation on anxiety-like behavior in rats by supplementing with magnesium their drinking water for 30 days. Anxiety-like behavior was induced by subcutaneous injection of veratrin 30 min before performing elevated plus maze and open field tests to measure anxiety levels and locomotion, respectively. We quantify the concentration of magnesium in plasma and cerebrospinal fluid. We used diazepam to compare the efficacy of magnesium supplementation as an anxiolytic agent. Our results show that rats supplemented with magnesium had a statistically significant decrease in anxiety levels with not effects on locomotion and a statistically significant increase in concentration of magnesium in plasma and cerebrospinal fluid. However, the anxiolytic effect of magnesium supplementation washes-out in 12 days. We discuss the advantages of using supplemental magnesium as anxiolytic.

First-principles investigations of composition-dependent mechanical properties of zinc-blende constituents of MgxZn1−xSyTe1−y rectangular quaternary system

Mechanical properties of zinc-blende MgxZn1−xSyTe1−y alloys and cationic (Mg) and anionic (S) composition dependence of these properties have been investigated theoretically through First-principles calculations. The elastic stiffness constants increase nonlinearly with increasing sulfur concentration at each fixed magnesium concentration, while each of them reduces with increasing magnesium concentration at each fixed sulfur concentration in any binary–ternary/ternary–quaternary system. Hardness of specimens increases nonlinearly with increasing sulfur concentration at each fixed magnesium concentration, while it reduces with increasing magnesium concentration at each fixed sulfur concentration in any binary–ternary/ternary–quaternary system. Each of the considered specimens is mechanically stable, ductile, elastically anisotropic, fairly compressible and plastic in nature. Blending of covalent and ionic bonding with domination of covalent, bending over stretching in chemical bonds and central character of force between atoms have been observed in each specimen. Computed Debye temperature confirms MgS as the hardest and ZnTe as the softest among all the considered specimens. Computed Gruneisen parameter of each specimen demonstrates anharmonic character of atom–atom interactions in each crystal. Thermal conductivity and melting temperature of each of the considered specimens have also been computed in the present study.

Nanostructured Strain-Hardened Aluminum–Magnesium Alloys Modified by C60 Fullerene Obtained by Powder Metallurgy: Part 1. The Effect of the Magnesium Concentration on the Structure and Phase Composition of Powders

This paper provides the first part of a study on the effect of magnesium on the structural phase composition and physical and mechanical properties of nanostructured aluminum–magnesium composite materials with the composition AlxMgy + 0.3 wt % C60 fullerene. Composite powders are obtained by the simultaneous mechanical activation of the initial materials in a planetary ball mill in an argon atmosphere. It is found that the powders have a complex hierarchical structure made up of 50–200 μm aggregates consisting of 5–10 μm strong high-density agglomerates, which in turn are a combination of nanoscale (30–60 nm) crystallites. It is found that the increase in magnesium concentration in the composite up to 18 wt % makes it possible to obtain crystallites with an average size of less than 30 nm during mechanical activation, while the size of aggregates is less than 50 μm. The maximum solubility of magnesium in aluminum with a crystallite size of 30–70 nm during mechanical activation is 15 wt % (17 at %). Using the differential scanning calorimetry method, it is found that nanostructured composites undergo irreversible structural phase transformations during heat treatment in a temperature range of 250–400°C: recrystallization, decomposition of the α-solid solution of magnesium in aluminum, and the formation of intermetallic β-(Al3Mg2), γ-(Al12Mg17) and carbide (Al4C3) phases. In addition, the Raman spectra contain peaks that, according to some sources, correspond to covalent compounds of aluminum with C60 fullerene—aluminum–fullerene complexes. The data that have been obtained will be used in further research to determine the parameters for the thermobaric treatment of nanocomposite powder mixtures in order to obtain and test bulk samples.

Nanostructured strain-hardened aluminum-magnesium alloys modified by C60 fullerene obtained by powder metallurgy Part 2. The effect of magnesium concentration on physical and mechanical properties

This paper is intended to continue the studies of magnesium effects on the structural phase composition, physical and mechanical properties of the nanostructured strain-hardened aluminum-magnesium alloys modified with C60 fullerene [1]. Previously obtained mechanically alloyed composite powders [1] were consolidated by direct hot extrusion method. Consolidation parameters were chosen based on previous studies of the structure and phase composition formation during mechanical alloying and heat treatment. It was found that an increase in magnesium concentration improves mechanical properties of extruded nanosructured composite materials, and additives modified by C60 fullerene stabilize the grain structure and slow down decomposition of α solid solution of magnesium in aluminum to 300 °C. Under similar thermobaric treatment Al82Mg18 (AMg18) not modified with C60 demonstrates a reduced α solid solution lattice constant and an increased average crystallite size. These processes are accompanied by sequential formation of γ, β′, and β phases, while γ and β′ are intermediate phases. The grain structure of extruded samples is typical for materials obtained in this way – grains are closely packed, elongated and oriented along the extrusion axis. The grain structure of extruded samples inherits the morphology of mechanically alloyed powders. Thus, mechanical alloying methods followed by intense plastic deformation (extrusion) improved mechanical properties significantly. Materials with ultimate tensile strength of 880 MPa; ultimate bending strength of 1100 MPa; microhardness up to 3300 MPa; and with the same density of 2.4–2.6 g/cm3 were obtained. This result demonstrates the prospects for using powder metallurgy techniques in the production of new nanostructured composite materials modified by C60 fullerene with improved physical and mechanical properties.

Biogeography and Environmental Drivers of Legionella pneumophila Abundance and Genotype Composition Across the West Bank: Relevance of a Genotype-Based Ecology for Understanding Legionella Occurrence.

The West Bank can be considered as a high-risk area for Legionella prevalence in drinking water due to high ambient temperature, intermittent water supply, frequent pressure loss, and storage of drinking water in roof containers. To assess occurrence of Legionella species, especially L. pneumophila, in the drinking water of the West Bank, the drinking water distribution systems of eight hospitals were sampled over a period of 2.3 years covering the seasonal cycle and the major geographic regions. To gain insight into potential environmental drivers, a set of physico-chemical and microbiological parameters was recorded. Sampling included drinking water and biofilm analyzed by culture and PCR-based methods. Cultivation led to the isolation of 180 strains of L. pneumophila that were genotyped by Multi-Locus Variable Number of Tandem Repeat Analysis (MLVA). Surprisingly, the abundance of culturable L. pneumophila was low in drinking water of the sampling sites, with only three out of eight sites where Legionella was observed at all (range: 30–500 CFU/Liter). By contrast, biofilm and PCR-based analyses showed a higher prevalence. Statistical analyses with physico-chemical parameters revealed a decrease of L. pneumophila abundance for water and biofilm with increasing magnesium concentrations (>30 mg/L). MLVA-genotype analysis of the L. pneumophila isolates and their spatial distribution indicated three niches characterized by distinct physico-chemical parameters and inhabited by specific consortia of genotypes. This study provides novel insights into mechanisms shaping L. pneumophila populations and triggering their abundance leading to an understanding of their genotype-specific niches and ecology in support of improved prevention measures.

Nanostructured strain hardened aluminum-magnesium alloys modified by C&lt;sub&gt;60&lt;/sub&gt; fullerene obtained by powder metallurgy. Part 1. Effect of magnesium concentration on the structure and phase composition of powders

This paper provides the first part of the study on the magnesium effect on the structural phase composition, physical and mechanical properties of nanostructured aluminum-magnesium composite materials with the composition AlxMgy + 0.3 wt.% C60 fullerene. Composite powders were obtained by the simultaneous mechanical activation of initial materials in a planetary ball mill in an argon atmosphere. It was found that the obtained powders have a complex hierarchical structure made up of 50–200 μm aggregates consisting of 5–10 μm strong high-density agglomerates, which in turn are a combination of nanoscale (30–60 nm) crystallites. It was found that the increase in magnesium concentration in the composite up to 18 wt.% makes it possible to obtain crystallites with an average size of less than 30 nm during mechanical activation, while the size of aggregates is less than 50 μm. The maximum solubility of magnesium in aluminum with a crystallite size of 30–70 nm during mechanical activation was 15 wt.% (17 at.%). Using the differential scanning calorimetry method, it was found that nanostructured composites undergo irreversible structural phase transformations during heat treatment in a temperature range of 250–400 °C: recrystallization, decomposition of the α-solid solution of magnesium in aluminum and formation of intermetallic β-(Al3Mg2), γ-(Al12Mg17) and carbide (Al4C3) phases. In addition, the Raman spectra contain peaks that, according to some sources, correspond to covalent compounds of aluminum with C60 fullerene – aluminum-fullerene complexes. The data obtained will be used in further research to determine parameters for the thermobaric treatment of nanocmposite powder mixtures in order to obtain and test bulk samples.

Effect of Magnesium Substitution on Structural, Magnetic and Biological Activity of Co(1-x)Mg(x)Fe2O4 Nano-colloids

Citrate coated magnesium substituted cobalt ferrite nanoparticles Co(1-x)Mg(x)Fe2O4 (where, x = 0.0, 0.25, 0.50, 0.75, 1.0) were prepared by sonochemical method. X-ray diffraction, energy dispersive X-ray analysis, scanning electron microscopy and Fourier transform infrared spectroscopy results confirmed the formation of spinel structures for all concentration values of substitution (x = 0.0–1.0). Furthermore, saturation magnetization was decreased upon increasing magnesium content. Hemolysis assay in vitro confirmed safety of nanoparticles for systemic administration and was non-significant upon increasing magnesium content when compared to untreated control. In vitro cytotoxicity screening against HepG2 cells revealed that cytotoxicity had an inverse relation with increasing magnesium concentration. Highly significant result was observed in the presence of x = 0.25 with percentage viability of 33.5 ± 2.28%. Similarly, antibacterial studies showed highly significant bacterial inhibition against pathogenic strains in the presence of x = 0.25. The results reveal the optimal value of magnesium co-doped functional magnetic materials and their application in biomedicine.

Magnesium-Accelerated Maillard Reactions Drive Differences in Adjunct and All-Malt Brewing

Magnesium impacts key processes in brewing including yeast metabolism and mash pH but is typically overshadowed in brewing studies, owing to the established centrality of calcium. Using flame atomic absorption spectroscopy (FAAS), a 33.7% average increase in magnesium concentration in commercially available beers brewed with 100% barley malt versus those brewed with adjunct grains was identified. Parallel analysis of brewing grains implicates rice in driving this discrepancy. Given the known catalytic properties of magnesium, its role in beer color development via Maillard chemistry using model systems and wort (unfermented beer) was investigated. Kinetic data were obtained by ultraviolet-visible spectrometry and reaction species were identified by electrospray ionization mass spectrometry. Magnesium accelerated Maillard chemistry in all systems in a dose-dependent manner. These findings reveal a divergence in outcomes of all-malt and adjunct brewing driven by magnesium-catalyzed color formation in the brewhouse. It is proposed that magnesium inhibits water mobility and serves as a Lewis acid catalyst to facilitate Maillard reactions.

Indium as a critical mineral: A research progress report

Indium (In) is a post-transition metal of Group 13 in the Periodic Table. It is a highly volatile chalcophile element which behaves in a moderately to highly incompatible manner. Abundance of indium in the continental crust is estimated at 0.01 ppm. Indium has been widely used in high-tech products, especially in emerging industry technology and national defense and security sectors. Therefore, it is called “critical mineral” in developed countries. Indium becomes one of the critical metals to support vigorous development of China’s emerging strategic industries. More than 90% of indium is recovered as a by-product of zinc mining. The most recent assessment of global indium reserves in 2018 was 79000 tones. China accounts for more than 18.2% of global indium reserves, while Peru, Canada, USA and Russia together own more than 62.4%. Indium occurs in different types of ore deposits. Indium-rich deposits include volcanic- and sediment-hosted exhalative massive sulfide deposits, epithermal deposits, polymetallic base metal vein-type deposits, granite-related tin-base-metal deposits, skarn deposits and porphyry copper deposits. These deposits are commonly associated with active oceanic or continental plate margins and orogenic belts with steep geothermal gradients due to enhanced magmatic activities. Most of indium deposits are associated with highly differentiated granites. Biotite is the main carrier mineral of indium. Recent research indicates that the enrichment of indium does not increase with the increase of crystallization differentiation in felsic magmatic systems. The increase of magnesium concentration in biotite reduces the potential of indium mineralization. The joint action of alkaline and sub-alkaline mafic and granitic magmas is an important prerequisite for the formation of high-grade indium deposits. Volcanic systems provide favorable conducive environment for the enrichment of indium. There are few studies on the enrichment of indium in silicate minerals. Garnet is a major tin-bearing skarn mineral at the Dulong Sn-Zn deposit of Yunan Province. Based on LA-ICP-MS analysis, indium concentration is 166.0–629.0 ppm in the garnet that was formed in the early skarn stage and 1.6–10.0 ppm in the garnet that was formed in the late skarn stage. The data indicate that the earlier garnet is enriched in indium than the later one. The data also show that indium has an apparent covariant relationship with tin, but an inverse correlation with aluminum. Multi-stage fluid activities in the evolution of magmatic hydrothermal processes are the key to enrichment of indium. Overprinting of multi-stage hydrothermal processes plays an important role in the formation of high-grade indium deposits. For example, indium-rich sphalerite in the Hammerlein skarn polymetallic deposit in Germany occurs around the early indium-free sphalerite grain, demonstrating overprinting of later indium-rich ore fluids. There are three ways for indium to substitute for zinc in sphalerite: (1) Cu++In3+↔2Zn2+, (2) Cu+/Ag++In2+↔2Zn2+, and (3) In3++Sn3++(vacancy)↔3Zn2+. The substitute of indium for zinc in sphalerite is slightly different due to the ore-formingelement (Cu, Ag, Sn, Ga, Ge, etc.). Tin can replace zinc with different valence state and other elements depending on the precipitation environment of sphalerite. Recent studies have shown that there are “indium window” and “indium explosion” that exist during the process of indium mineralization. Modern analytical technology and experimental simulation reveal the mechanism for “indium explosion” effect in the Dulong Sn-Zn deposit of Yunan Province. In this mechanism, lattice displacement and vacancies in small number within sphalerite facilitate indium enrichment in {111} direction in sphalerite. In summary, several items should be followed for the future research and exploration of resources of critical mineral indium: (1) Fully understand the occurrence state of indium in major carrier minerals and reveal mechanism for selective super-enrichment of indium; (2) improve our understanding of indium enrichment mechanism in different geological settings, which would effectively guide future exploration of indium deposits; (3) renovate indium recycling technologies and seek its substitutes.