Search results for "Magnesium"
showing 10 items of 490 documents
AZ31 magnesium alloy recycling through friction stir extrusion process
2015
Friction Stir Extrusion is a novel technique for direct recycling of metal scrap. In the process, a dedicated tool produces both the heat and the pressure to compact and extrude the original raw material, i.e., machining chip, as a consolidated component. A proper fixture was used to carry out an experimental campaign on Friction Stir Extrusion of AZ31 magnesium alloy. Variable tool rotation and extrusion ratio were considered. Appearance of defects and fractures was related to either too high or too low power input. The extruded rods were investigated both from the metallurgical and mechanical points of view. Tensile strength up to 80 % of the parent material was found for the best combina…
Impact of Green Vegetables and Green Smoothies on Enamel Mineral Composition In Vitro
2019
Background: Recently, smoothies with a high vegetable content have become very popular, especially among young adults. Objectives: This in vitro study was conducted to determine the erosive potential of selected green vegetables and green smoothies on human dental enamel. Methods: A total of ten green smoothies and eight freshly mixed vegetables were chosen, and pH, calcium and oxalic acid contents were measured. The enamel specimens were obtained from wisdom teeth and incubated with 3 selected foods (spinach, parsley, or green smoothie) for 12 and 24 hours (N = 6). Control samples were incubated with a physiological salt solution. An electron probe microanalyzer (Jeol JXA 8900RL) was utili…
Mineral Profile of Children’s Fast Food Menu Samples
2017
Abstract Children’s fast food menus, including hamburgers served with french fries, dessert, and a soft drink, were analyzed to obtain the mineral profile of trace elements. The developed analytical methodology involved sample digestion under pressure inside a microwave oven with a mixture of HNO3 and H2O2 and inductively coupled plasma-optical emission spectrometry. The method was validated by carrying out the analysis of certified reference materials (NIST 1570a spinach leaves, NCS ZC73016 chicken, and NIST 1568a rice flour) and using recovery experiments. Repeatability was verified by analyzing replicate samples. Twenty-six elements were studied, 12 of which—aluminum, barium, calcium, co…
Magnesium Status in Alzheimer's Disease: A Systematic Review
2016
The interest in poor magnesium (Mg) status as risk factor for Alzheimer's disease (AD) is increasing due to its antioxidant and neuroprotective properties. A systematic PubMed literature search of studies investigating Mg status was undertaken comparing AD to healthy controls (HCs) or patients with medical illness (medical controls [MCs]). Standardized mean differences (SMDs) ± 95% confidence intervals (CIs) were calculated for all outcomes. Of 192 potentially eligible studies, 13 were included (559 patients with AD, 381 HCs, and 126 MCs). Compared to HCs, patients with AD had significantly lower Mg in cerebrospinal fluid (2 studies; SMD = -0.35; P =.02) and in hair (2 studies; SMD = -0.75;…
Specific interaction of IM30/Vipp1 with cyanobacterial and chloroplast membranes results in membrane remodeling and eventually in membrane fusion.
2016
The photosynthetic light reaction takes place within the thylakoid membrane system in cyanobacteria and chloroplasts. Besides its global importance, the biogenesis, maintenance and dynamics of this membrane system are still a mystery. In the last two decades, strong evidence supported the idea that these processes involve IM30, the inner membrane-associated protein of 30kDa, a protein also known as the vesicle-inducing protein in plastids 1 (Vipp1). Even though we just only begin to understand the precise physiological function of this protein, it is clear that interaction of IM30 with membranes is crucial for biogenesis of thylakoid membranes. Here we summarize and discuss forces guiding I…
Magnesium and Other Biometals in Oxidative Medicine and Redox Biology
2017
No abstract available.
Mg2+ homeostasis and transport in cyanobacteria – at the crossroads of bacterial and chloroplast Mg2+ import
2018
Abstract Magnesium cation (Mg2+) is the most abundant divalent cation in living cells, where it is required for various intracellular functions. In chloroplasts and cyanobacteria, established photosynthetic model systems, Mg2+ is the central ion in chlorophylls, and Mg2+ flux across the thylakoid membrane is required for counterbalancing the light-induced generation of a ΔpH across the thylakoid membrane. Yet, not much is known about Mg2+ homoeostasis, transport and distribution within cyanobacteria. However, Mg2+ transport across membranes has been studied in non-photosynthetic bacteria, and first observations and findings are reported for chloroplasts. Cyanobacterial cytoplasmic membranes…
Ruegeria denitrificans sp. nov., a marine bacterium in the family Rhodobacteraceae with the potential ability for cyanophycin synthesis.
2018
Strain CECT 5091T, an aerobic, marine, Gram-reaction- and Gram-stain-negative, chemoheterotrophic bacterium was isolated from oysters harvested off the Spanish Mediterranean coast. Analysis of the 16S rRNA gene sequence placed the strain within the genus Ruegeria , in the family Rhodobacteraceae , with 16S rRNA gene similarities of 98.7, 98.7 and 98.4 % to Ruegeria conchae , Ruegeria atlantica and Ruegeria arenilitoris , respectively. Average nucleotide identities (ANI) and in silico DNA–DNA hybridization (DDH) were determined, comparing the genome sequence of CECT 5091T with those of the type strains of 12 species of the genus Ruegeria : the values obtained were always below the thresholds…
Effects of alternative electron acceptors on the activity and community structure of methane-producing and consuming microbes in the sediments of two…
2017
The role of anaerobic CH4 oxidation in controlling lake sediment CH4 emissions remains unclear. Therefore, we tested how relevant EAs (SO42−, NO3−, Fe3+, Mn4+, O2) affect CH4 production and oxidation in the sediments of two shallow boreal lakes. The changes induced to microbial communities by the addition of Fe3+ and Mn4+ were studied using next-generation sequencing targeting the 16S rRNA and methyl-coenzyme M reductase (mcrA) genes and mcrA transcripts. Putative anaerobic CH4-oxidizing archaea (ANME-2D) and bacteria (NC 10) were scarce (up to 3.4% and 0.5% of archaeal and bacterial 16S rRNA genes, respectively), likely due to the low environmental stability associated with shallow depths.…
Magnesium and Micro-Elements in Older Persons
2021
Macro- and micro-element deficiencies are widely diffused in older people. The deficiency of these elements in older people is often attributable to malnutrition, even if other medical conditions (such as gastrointestinal problem) or non-medical conditions (such as polypharmacy) can lead to these deficiencies [1]. It is estimated that malnutrition is present in 1.3–47.8% of older people living in the community, being higher in other settings and in low-middle income countries [2].