(n.) A light silver-white metallic element, malleable and ductile, quite permanent in dry air but tarnishing in moist air. It burns, forming (the oxide) magnesia, with the production of a blinding light (the so-called magnesium light) which is used in signaling, in pyrotechny, or in photography where a strong actinic illuminant is required. Its compounds occur abundantly, as in dolomite, talc, meerschaum, etc. Symbol Mg. Atomic weight, 24.4. Specific gravity, 1.75.
Example Sentences:
(1) The following conclusions emerge: (i) when the 3' or the 3' penultimate base of the oligonucleotide mismatched an allele, no amplification product could be detected; (ii) when the mismatches were 3 and 4 bases from the 3' end of the primer, differential amplification was still observed, but only at certain concentrations of magnesium chloride; (iii) the mismatched allele can be detected in the presence of a 40-fold excess of the matched allele; (iv) primers as short as 13 nucleotides were effective; and (v) the specificity of the amplification could be overwhelmed by greatly increasing the concentration of target DNA.
(2) Subunits maintained under the above ionic conditions were compared with 30S and 50S particles at low (6 mM) magnesium concentration with respect to the reactivity of individual ribosomal proteins to lactoperoxidase-catalyzed iodination.
(3) The association constants K'A, KN, and K'N in the scheme (see article), were determined for the magnesium salts of ADP, adenyl-5'-yl imidodiphosphate AMP-P(NH)P, and PPi.
(4) Simple interconversion cannot account for the changes in binding that occur upon adding GMP-PNP or removing magnesium, since the increase in [R2]t exceeds the decrease in [R1]t. Moreover, the apparent amount of high-affinity complex exhibits a biphasic dependence on the concentration of [3H]histamine; an increase at low concentrations is offset by a decrease that occurs at higher concentrations.
(5) There were no relationships between blood pressure and calorie-adjusted intakes of fats, carbohydrates, sodium, potassium, calcium or magnesium.
(6) Renal excretion of calcium and magnesium postflight was higher than preflight.
(7) Although GTP most potently inhibited [125I]beta h-endorphin binding in the presence of sodium, inhibition of [125I]beta h-endorphin binding by GTP was also observed in the presence of the monovalent cations lithium and potassium, but not the divalent cations magnesium, calcium, or manganese.
(8) The contents of magnesium, potassium and zinc plasma did not correlate with the corresponding concentrations in skeletal muscle or circulating blood cells, as investigated in healthy controls, diabetics and in all subjects together, implying that the plasma concentrations are not useful in the assessment of electrolyte status.
(9) The decomposition of nafcillin and penicillin G solutions was hastened significantly by magnesium sulphate due to effect on the pH values of the solutions.
(10) In the present study, maternal and fetal zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), magnesium (Mg), and calcium (Ca) status has been studied in Sprague-Dawley (SD) and Wistar rats.
(11) The effect of age of the ewe and pregnancy on concentrations of plasma calcium, phosphorus and magnesium and its relationship to the bent-leg syndrome in lambs, were investigated.
(12) The slight radioprotective action of inosine, when injected intraperitoneally to mice shortly before gamma-irradiation, can be enhanced by the administration of magnesium aspartate.
(13) Thus, magnesium may be useful in the management of ventricular fibrillation during ischemia.
(14) It depended on the quantal content and 3-exponential EPC could be transformed in 2-exponential and later to monoexponential ones if increasing concentration of magnesium ions.
(15) The effect of volume expansion on sodium, calcium and magnesium remaining in the proximal tubule was relatively modest and not affected by furosemide.
(16) The dietary intake of magnesium is borderline compared with the recommended dietary allowances.
(17) Metabolism of carbaryl by the fat body is affected by the age of the larva, the pH of the incubation medium, and the concentration of magnesium chloride in the incubation medium.
(18) All calcium, magnesium, and zinc contents per bone decreased in the 1- and 2-mg caffeine groups as compared to either controls or 0.5-mg caffeine group, whereas phosphorus stayed relatively constant regardless of the different levels of caffeine intake.
(19) Magnesium (Mg) deficiency, nicotine, and high dietary cholesterol are contributing factors that accentuate adverse effects of vitamin D.
(20) With magnesium-Ringer as external bathing solutions, amiloride and ouabain failed to stimulate oxygen consumption.
Strontium
Definition:
(n.) A metallic element of the calcium group, always naturally occurring combined, as in the minerals strontianite, celestite, etc. It is isolated as a yellowish metal, somewhat malleable but harder than calcium. It is chiefly employed (as in the nitrate) to color pyrotechnic flames red. Symbol Sr. Atomic weight 87.3.
(n.) A radioactive isotope of strontium produced by certain nuclear reactions, and constituting one of the prominent harmful components of radioactive fallout from nuclear explosions; also called radiostrontium. It has a half-life of 28 years.
Example Sentences:
(1) Specimens of human bone from the site exhibited lower strontium levels and strontium-to-calcium ratios than deer specimens from the same site, reinforcing paleodemographic evidence that the human populations that inhabited this site included substantial amounts of meat in their diets.
(2) Revascularisation was evaluated with radioactive microspheres; formation of new bone was assessed by incorporation of strontium, and resorption was assessed by measuring the reduction of graft weight.
(3) Compared with the transected control group, resection decreased strontium absorption per unit weight of mucosa (specific absorption) in the proximal segment.
(4) Human spermatozoa incubated in a strontium- or lanthanum-based medium, or T6 + 10% maternal human serum (HS) supplemented with 12 mM 8-bromo cyclic guanosine 3,5'-monophosphate and 10 mM imidazole for a 4-hour period before transfer to fresh T6 + 10% HS for a further 6 hours, demonstrated a significant increase (P less than 0.05) in acrosomal loss compared with T6 + 10% HS for a total 10-hour incubation.
(5) Concentration factors of strontium-90 in aquatic organisms and substrates are higher in a dystrophic lake than in the other types.
(6) In the absence of calcium, other divalent cations such as magnesium, strontium, or manganese were not efficient substitutes for calcium.
(7) A similar effect was obtained by strontium, but magnesium was ineffective.4.
(8) The predicted fallout of strontium-90 in 1970 is less than 1 percent of that during the peak year 1963.
(9) The decontamination of strontium was checked by applying non-dispersive fluorescence X-ray analysis using 133Ba as irradiating source.
(10) Strontium ions, added to a calcium-deficient bathing solution, were shown to attenuate the increased 45Ca uptake by the lens.
(11) Results are presented to show that calcium and strontium act at the same site but strontium is a more sensitive probe for that site.
(12) The elements added to increase radiopacity in the composite materials are barium, strontium, zinc, zirconium, and ytterbium.
(13) Heat-induced release of dipicolinic acid occurred much faster with barium and strontium spores than with calcium spores.
(14) Annual dose rates of 27 millirads to bone and 4 millirads to the whole body correspond to the highest average concentrations of strontium-90 and cesium-137 so far observed.
(15) Strontium (2.5 mM) significantly attenuated the response to CCK-OP and bethanechol, but not to KCl.
(16) Strontium can replace calcium in a number of physiological and biochemical processes.
(17) A high percentage of the strontium retained during both oral and intravenous administration was excreted in 30 days after the discontinuation of the strontium administration and there was no evidence of long term retention.
(18) Enhanced HR with strontium was greater with basophils from normal subjects than from subjects with allergic rhinitis.
(19) In vascular smooth muscle that does not contract spontaneously, similar deposits of strontium were only seen if the muscle was depolarized during or glycerinated before exposure to the strontium-containing solution.
(20) The results of a study of 975 pterygia treated surgically and immediately with Strontium 90 are presented.