The determination of calcium and magnesium in acetylene flames

Ramakrishna, T. V.; West, Philip W.; Robinson, James W.

doi:10.1016/s0003-2670(00)86737-9

Cited by 33 publications

(9 citation statements)

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“…K (5 mg/ml) was present in both samples and standards to overcome ionization and La (2 mg/ml) was added as a releasing agent (Ramakrishna, West & Robinson, 1968).…”

Section: Measurements Of Ca and Mg Bound To Membranesmentioning

confidence: 99%

Role of membrane-bound Ca in ghost permeability to Na and K

Romero

1976

J. Membrain Biol.

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The permeability of red cell ghosts to K is determined by the amount of membrane-bound Mg which, in turn, depends on internal Mg. Contrasting with such effect, an increase in cellular Ca raises K permeability. To test whether this action is due to a competitive displacement of membrane Mg, the free Ca content of human red cell ghosts was altered by means of Ca-EGTA buffers. Net Na and K movements as well as Ca and Mg bindings were assessed after incubation in a Na-medium at 37 degrees C. Raising Ca from 3 X 10(-7) to 1 X 10(-2) M caused a large K efflux with very little Na gain. Under similar conditions, Ca binding was increased without affecting membrane-bound Mg. Both Ca binding and K loss were markedly diminished by either adding ATP to the hemolytic medium or increasing internal Mg at a fixed Ca concentration. A Scatchard analysis showed three Ca binding sites, two of them having high affinity. It is concluded that Ca action does not arise from a displacement of membrane-bound Mg but from binding to different sites in the membrane. Presumably, high affinity sites are involved in the control of K permeability.

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“…K (5 mg/ml) was present in both samples and standards to overcome ionization and La (2 mg/ml) was added as a releasing agent (Ramakrishna, West & Robinson, 1968).…”

Section: Measurements Of Ca and Mg Bound To Membranesmentioning

confidence: 99%

Role of membrane-bound Ca in ghost permeability to Na and K

Romero

1976

J. Membrain Biol.

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“…This solution was used for P and Ca determination. The Ca concentration was determined using an atomic absorption spectrophotometer (Perkin-Elmer Analyst 700 MHS) using the method of Ramakrishna et al (1968). The concentration of P was determined spectrophotometrically using the method of Cavell (1955).…”

Section: Methodsmentioning

confidence: 99%

Effect of phytase supplementation on growing pigs performance

Šefer¹,

Petrujkić²,

Marković³

et al. 2012

ACTA VET-BEOGRAD

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Dietary concentrations of phytate are crucial for its anti-nutritive properties and its negative impact on P availability. The increase of dietary phytate level is shown to increase endogenous losses of amino acids and minerals in pigs. The partial availability of the P component of phytate to simple-stomached species attains importance as the world's rock phosphate reserves are not renewable, which could lead to a P supply crisis in the future. Supplementing phytase is becoming increasingly common as a method to improve the availability of P in plant ingredients containing high levels of phytate P. Fourty-eight pigs (Swedish Landrace boars × Dutch landrace sows) weaned at day 35 with an initial BW of 8.72±0.28 kg were used for a 40-day weaner performance study. The study was structured as a complete randomized design to evaluate the response of weaner pigs to four concentrations of microbial phytase produced by Aspergillus niger: (T1) basal diet; (T2) basal diet + 1000 FTU/kg; (T3) diet with decreased dicalcium phosphate + 1000 FTU/kg; and (T4) diet with no dicalcium phosphate + 1000 FTU/kg. Control group of piglets (T1) has achieved standard body mass while addition of phytase in meal increased body mass by 6.59% in T2 and 7.52% in T3. Phytase supplementation prevented decreased body weight gain diets where available phosphorous level was reduced by 50. The amount of consumed feed per day was not significantly different. Feed efficiency of T2 and T3 groups was by 3.23% better and of T4 for 11.29% lower compared to the control group of piglets (T1). Lower production results achieved by the use of low phosphorous diets can be avoided to a certain level by the use of microbial phytase. The use of phytase in pig diet significantly improved phosphorous availability, as well as of other mineral substances from the phytate complex. [Projekat Ministarstva nauke Republike Srbije, br. III46002

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“…For P determination, a series of concentrations were used ranging from 10 to 50 ppm P and digested samples diluted to fit this curve. The Ca concentration of diets was determined using a Varian '50' atomic absorption spectrophotometer using the ashed sample (Ramakrishna et al, 1968). For Ca determination, a series of concentrations were used ranging from 1 to 5 ppm Ca and digested samples diluted to fit this curve.…”

Section: Laboratory Analysis Of Dietsmentioning

confidence: 99%

“…This solution was used for P and Ca determination. The Ca concentration was determined using a Varian '50' atomic absorption spectrophotometer (Ramakrishna et al, 1968). The concentration of P was determined spectrophotometrically using the method of Cavell (1955).…”

Section: Bone Analysismentioning

confidence: 99%