Search results for "Magnesium"

Biochemical characteristics of the soluble organic matrix from the shell of three recent terebratulid brachiopod species.

2008

7 pages; International audience; To build their shells, brachiopods secrete a mixture of proteins and polysaccharides, collectively called the organic matrix. This matrix mediates the calcification process by allowing crystal nucleation followed by elongation and finally by stopping the crystal growth. Ultimately, the matrix controls the different microstructures formed. Brachiopod shells are composites with both organic and inorganic constituents intimately associated. This work represents an attempt to characterize the matrices using two combined approaches: (1) scanning electron microscopy for localization within the shell, (2) analysing extracted matrices at the molecular level to deter…

Probing the Extremes of Covalency in M-Al bonds: Lithium and Zinc Aluminyl Compounds.

2022

Synthetic routes to lithium, magnesium, and zinc aluminyl complexes are reported, allowing for the first structural characterization of an unsupported lithium-aluminium bond. Crystallographic and quantum-chemical studies are consistent with the presence of a highly polar Li-Al interaction, characterized by a low bond order and relatively little charge transfer from Al to Li. Comparison with magnesium and zinc aluminyl systems reveals changes to both the M-Al bond and the (NON)Al fragment (where NON=4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene), consistent with a more covalent character, with the latter complex being shown to react with CO<sub>2</sub> vi…

Artificial cartilage bio-matrix formed of hyaluronic acid and Mg2+-polyphosphate.

2016

Here we show that inorganic polyphosphate (polyP), a polyanionic metabolic regulator consisting of multiple phosphate residues linked by energy-rich phosphoanhydride bonds, is present in the synovial fluid. In a biomimetic approach, to enhance cartilage synthesis and regeneration, we prepared amorphous polyP microparticles with Mg2+ as counterions. The particles were characterised by X-ray diffraction (XRD), energy-dispersive X-ray (EDX) and Fourier transformed infrared spectroscopic (FTIR) analyses. Similar particles were obtained after addition of Mg2+ ions to a solution containing hyaluronic acid, as a major component of the synovial fluid, and soluble Na-polyP. The viscous paste-like ma…

MAGNESIUM IN AGING

2011

Magnesium and aging.

2009

Over the past decades, the clinical relevance and biological significance of magnesium (Mg) have been documented. Deficiency in Mg, aside from having a negative impact on the energy production pathway required by mitochondria to generate ATP, also reduces the threshold antioxidant capacity of the aging organism and its resistance to free-radical damage. Mg also acts as an antioxidant against free radical damage of the mitochondria. Chronic inflammation and oxidative stress have both been identified as pathogenic factors in aging and in several age-related diseases. Chronic Mg deficiency results in excessive production of oxygen-derived free radicals and low grade inflammation. Aging is very…

Magnesium and Health

2019

Magnesium (Mg) is the second most abundant cation after potassium in the intracellular compartment and has a critical role in modulating a large variety of cellular activities and metabolic pathways. Mg is cofactor in over 300 enzymatic reactions including all reactions that involve ATP utilization and transfer [1,2]. Over the past decades, the clinical relevance of Mg and its impact on health has been documented. In the human body, around 24 grams (1 mole) of Mg are present. Less than 1% of total Mg is in the serum; normal serum Mg concentrations range between 0.75-0.95 mmol/L (1.7-2.5 mg/dL or 1.5-1.9 meq/L). In healthy adults, daily Mg requirement is around 300-400 mg (5 to 6 mg/kg/day) …

Effect of Magnesium Supplementation on Inflammatory Parameters: A Meta-Analysis of Randomized Controlled Trials

2022

Magnesium (Mg) may have several beneficial effects on human health outcomes. One hypothesized mechanism eliciting such effects is the action of Mg on serum inflammatory parameters. However, studies on this topic to date have several important limitations. Therefore, the present systematic review and meta-analysis aimed to summarize the current state of the art of all randomized control trials (RCTs) investigating the effects of Mg supplementation versus placebo on serum parameters of inflammation. We searched several databases until 23rd November 2021 for RCTs. Eligible studies were RCTs investigating the effect of oral Mg supplementation vs. placebo and having serum inflammatory markers as…

Some observations on the use of matrix modifiers in the determination of aluminum by electrothermal atomic absorption spectrophotometry

1989

Abstract Some evidence demonstrating that the use of matrix modifiers is necessary to obtain good calibration lines in the determination of aluminum by graphite furnace atomic absorption spectrophotometry is provided. It was found that the most sensitive results were obtained when Mg(NO 3 ) 2 was used instead of NH 4 H 2 PO 4 .

Sodium Chloride and Magnesium Chloride affected by Ripening of Camembert Cheese

1993

Ripening of cheese with three kinds of salt treatment was studied using MgCl 2 , NaCl or a mixture of the two. Proteolysis was followed by determination of TCA-soluble nitrogen and quantitative electrophoresis. A rapid one-step method for free fatty acids was used to determine short and long-chin fatty acids. In the presence of magnesium, proteolysis increased, even with NaCl, which seemed to delay the magnesium activation. Lipolysis was retarded by NaCl, which decreased the level of free fatty acids. An imbalance between proteolysis and lipolysis could be responsible for the unpleasant flavor of the cheese containing both MgCl 2 and NaCl

Relationship between PTH, sex steroid and bone turnover marker measurements and bone density in recently postmenopausal women

2003

Objective: It is conceivable that, since menopause accelerates the continuous bone loss determined by age, a specific configuration of bone mass determinants during the first postmenopausal years occurs. Methods: To establish their value as indicators of bone mass in women with recent natural menopause, we assessed relationships between bone mineral density (BMD) and age, menopausal age, body mass index (BMI), PTH, sex steroid hormones (estradiol and testosterone), and several markers of bone turnover in urine (N-telopeptide and calcium/creatinine ratio) or serum (osteocalcin (OC), total alkaline phosphatase (ALP), total and ionic calcium (iCa), phosphate (P) and magnesium (Mg)) for a group…