Isolated Renal Magnesium Loss

Lung tissues have been obtained from workmen with defined asbestos fiber exposure. These tissues have been prepared by the carbon extraction technique and examined with the electron microprobe analyzer. The uncoated fibers present in these specimens have been chemically characterized and compared with standard reference asbestos samples. The bulk chemistry of the fibers observed in lung tissues is similar to that of the reference fibers so that identification may be made. However, a statistical analysis of the measured emission characteristics from anthophyllite and amosite indicates that some magnesium loss has taken place. This loss appears to correlate with the magnesium content of the fibers. A slight iron increase was also noted in the same fibers, probably related to an incipient asbestos body formation.

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Control of Magnesium Loss During Laser Welding of Al-5083 Using a Plasma Suppression Technique

Journal of Engineering for Industry ◽

10.1115/1.3185998 ◽

1985 ◽

Vol 107 (3) ◽

pp. 275-280 ◽

Cited By ~ 28

Author(s):

A. Blake ◽

J. Mazumder

Keyword(s):

Laser Welding ◽

Alloy Composition ◽

Tensile Tests ◽

Parent Material ◽

Plasma Formation ◽

Radiographic Examination ◽

Alloy Chemistry ◽

Suppression Technique ◽

Order Of Magnitude ◽

Magnesium Loss

A major problem of autogeneous laser welding Al-5083 is the loss of magnesium by evaporation or plasma formation. This consequently results in welds of low tensile strength and unacceptable porosity. A method has been developed to control plasma formation during welding resulting in satisfactory welds with little or no magnesium loss and porosity. Plasma formation was controlled by manipulation of a main gas jet in a shielding arrangement during welding. Shielding gas pressure needed to suppress the plasma was within an order of magnitude of the theoretically estimated pressure required to sustain a vapor filled “keyhole.” The experiment was carried out using a 10 kW CW-CO2 laser. A two-level factorial experimental design correlated the effects of the independent laser processing variables with as-welded alloy chemistry. Alloy composition was characterized quantitatively using electron probe microanalysis techniques. Observations revealed that magnesium loss could be minimized to as low as 0.9 percent. Radiographic examination and tensile tests further demonstrated that low porosity welds with strengths at least as great as the parent material may be produced by controlling alloy composition via a specially designed inert gas shield.

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Magnesium loss in magnesium deficient subjects with and without physical exercise during prolonged hypokinesia

Clinical & Investigative Medicine ◽

10.25011/cim.v31i1.3137 ◽

2008 ◽

Vol 31 (1) ◽

pp. 16 ◽

Cited By ~ 2

Author(s):

Costas B. Tsiamis ◽

Kostas K. Kakuris ◽

Viktor A. Deogenov ◽

Kosmas B. Yerullis

Keyword(s):

Physical Exercise ◽

Active Control ◽

Healthy Subjects ◽

Experimental Period ◽

The Body ◽

Healthy Male ◽

Control Subjects ◽

Healthy Male Volunteers ◽

Experimental Values ◽

Magnesium Loss

Objective: To show the effect of hypokinesia (HK; diminished movement) on magnesium (Mg2+) loss in Mg2+ deficient subjects and the effect of physical exercise and on Mg2+ deficiency with and without physical exercise: Mg2+ balance, serum Mg2+ concentration and Mg2+ loss were measured. Methods: Studies were conducted on 30 healthy male volunteers during a pre-experimental period of 30 days and an experimental period of 364 days. They were divided equally into three-groups: unrestricted active control subjects (UACS), continuous hypokinetic subjects (CHKS) and periodic hypokinetic subjects (PHKS). The UACS group ran average distances of 9.3 ± 1.2 km.day-l; the CHKS group walked average distances of 0.9 ± 0.2 km.day-l; and the PHKS group walked and ran average distances of 0.9 ± 0.2 km and 9.3 ± 1.2 km.day-l for 5-and 2-days per week, respectively. Results: Mg2+ deficiency, serum Mg2+ level, fecal and urine Mg2+ loss increased (P < 0.05), in the PHKS and CHKS groups compared with their pre-experimental values and the values in the UACS group. However, serum Mg2+ concentration, urine and fecal Mg2+ loss and Mg2+ deficiency increased more (P < 0.05) in the PHKS group than in the CHKS group. Conclusions: Mg2+ deficiency is more evident with than without physical exercise and Mg2+ loss is exacerbated more with higher than lower Mg2+ deficiency. This indicates that Mg2+ deficiency with and without physical exercise and Mg2+ loss with higher and lower Mg2+ deficiency is due to inability of the body to use Mg2+ and more so when physically healthy subjects are submitted to prolonged periodic than continuous hypokinesia.

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31P nuclear magnetic resonance and zero-point titration compared for measuring free magnesium concentration in erythrocytes

Clinical Chemistry ◽

10.1093/clinchem/37.12.2076 ◽

1991 ◽

Vol 37 (12) ◽

pp. 2076-2080 ◽

Cited By ~ 8

Author(s):

W B Geven ◽

G M Vogels-Mentink ◽

J L Willems ◽

C H v Os ◽

C W Hilbers ◽

...

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

31P Nmr ◽

Zero Point ◽

Magnesium Concentration ◽

Cell Water ◽

Ionized Magnesium ◽

31P Nuclear Magnetic Resonance ◽

L Cell ◽

Magnesium Loss

Abstract Intracellular ionized magnesium concentrations ([Mg2+]i) were measured in erythrocytes by 31P nuclear magnetic resonance (NMR) and zero-point titration in 14 controls and seven patients with renal magnesium loss. The mean intracellular ionized magnesium concentration in controls measured by 31P NMR was 0.20 (SD 0.03) mmol/L cell water, compared with 0.55 (SD 0.12) mmol/L cell water by zero-point titration. Total erythrocyte magnesium content measured with the lysate method was 0.63 mmol/L cell water higher than estimated by 31P NMR, probably because not all magnesium complexes are fully visible to the NMR technique. We found a positive correlation between plasma ultrafiltrable magnesium and [Mg2+]i irrespective of the [Mg2+]i assay used. [Mg2+]i measured with 31P NMR correlated modestly but significantly with [Mg2+]i determined by zero-point titration (r = 0.58, P less than 0.02). Washing erythrocytes before the zero-point titration decreased the ATP content and the cell water fraction, which led to overestimation of [Mg2+]i by zero-point titration. Although absolute values for [Mg2+]i differ with the assay used, both methods determined significantly lower values for [Mg2+]i in patients with isolated renal magnesium loss.

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