Evaluation of a New Automatic Calcium Ion Analyzer

Abstract We evaluated a new automatic analyzer for ionized cal¬cium (Ca2+), the Orion Model SS-20, based on a flow-through ion-exchange electrode. Ca2+ was measured in heparinized whole blood and serum. Within-day variation was 1.2%, day-to-day variation 1.6 %, and analytical re-covery 92.4%. Over the physiological range interference by K± and Mg2+ was negligible; major changes in ionic strength, induced by changes in Na+ concentration, made correction for a sodium error necessary. Within the physiological range, Ca2+ was inversely correlated to variations in pH. Therefore, to compare Ca2+ values, correction to an apparent pH of 7.40 should be made. The calcium binding effect of heparin was negligible when minimal (4.4 int. units/m1) concentrations of heparin were used. Storage of serum at 4 °C for one week resulted in a 4% decrease in apparent serum Ca2+, primarily owing to an increase in pH during storage. In normal material, mean values for blood- and serum-Ca2+ (1.10 and 1.07 mmol/liter, respectively) were close to results obtained by previous systems. Errors caused by disturbances in the fluid flow and non-function of half the electrodes we re¬ceived were the major inconveniences of the analyzer. We conclude that this new analyzer gives decisive advantages in measurement of Ca2+, making this important analysis possible as a routine laboratory test for the first time

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Binding of calcium ions to bovine αsl-casein and precipitability of the protein–calcium ion complexes

Journal of Dairy Research ◽

10.1017/s002202990002094x ◽

1980 ◽

Vol 47 (1) ◽

pp. 113-122 ◽

Cited By ~ 77

Author(s):

Douglas G. Dalgleish ◽

Thomas G. Parker

Keyword(s):

Ionic Strength ◽

Calcium Ions ◽

Calcium Ion ◽

Calcium Binding ◽

Calcium Concentration ◽

Binding Constants ◽

Substitution Effects ◽

Binding Isotherms ◽

Decreasing Ph ◽

Increasing Temperature

SummaryBinding isotherms for the calcium ion–αsl-casein system have been measured, as functions of ionic strength, temperature, and pH, and the isotherms have been analysed in terms of binding constants modified by substitution effects. The results demonstrate that the strength of binding is increased with increasing temperature and decreased by increasing ionic strength or decreasing pH, all of which may be explained semi-quantitatively. Parallel studies on the precipitability of the αsl-casein–Ca2+ complexes showed that there is considerable variation in the extent of calcium binding required to initiate precipitation of the protein, and in the calcium concentration necessary to achieve the required extent of ligand binding.

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A study of the Ca2+ – Arsenazo III system and its application to the spectrophotometric determination of free calcium in solution

Canadian Journal of Chemistry ◽

10.1139/v90-298 ◽

1990 ◽

Vol 68 (11) ◽

pp. 1932-1936 ◽

Cited By ~ 4

Author(s):

Byron Kratochvil ◽

Xi-Wen He

Keyword(s):

Ionic Strength ◽

Calcium Ion ◽

Calcium Binding ◽

Metal Ion ◽

Arsenazo Iii ◽

Free Calcium ◽

Ionic Calcium ◽

Free Metal ◽

Free Metal Ion

A two-wavelength method was applied to the determination of free, ionic calcium with Arsenazo III in solutions containing calcium-binding ligands. By this procedure impurities in the indicator can be corrected for, thereby allowing the use of commercial indicator preparations with purities as low as 80%. Only a 1:1 complex with a conditional log stability constant of 4.28 ± 0.13 at pH 4.6 and ionic strength 0.1 was found under the conditions studied. Key words: free metal ion determination, calcium ion speciation, spectrophotometry, arsenazo III, ion increment method for speciation.

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A concise python implementation of the lattice Boltzmann method on HPC for geo-fluid flow

Geophysical Journal International ◽

10.1093/gji/ggz423 ◽

2019 ◽

Vol 220 (1) ◽

pp. 682-702

Author(s):

Peter Mora ◽

Gabriele Morra ◽

David A Yuen

Keyword(s):

Fluid Flow ◽

Lattice Boltzmann Method ◽

Lattice Boltzmann ◽

Parallel Implementation ◽

Pedagogical Tool ◽

Python Scripting ◽

Flow Through ◽

Scripting Language ◽

Boltzmann Method ◽

First Time

SUMMARY The lattice Boltzmann method (LBM) is a method to simulate fluid dynamics based on modelling distributions of particles moving and colliding on a lattice. The Python scripting language provides a clean programming paradigm to develop codes based on the LBM, however in order to reach performance comparable to compiled languages, it needs to be carefully implemented, maximizing its vectorized tools, mostly integrated in the NumPy module. We present here the details of a Python implementation of a concise LBM code, with the purpose of offering a pedagogical tool for students and professionals in the geosciences who are approaching this technique for the first time. The first half of the paper focuses on how to vectorize a 2-D LBM code and show how if carefully done, this allows performance close to a compiled code. In the second part of the paper, we use the vectorization described earlier to naturally write a parallel implementation using MPI and test both weak and hard scaling up to 1280 cores. One benchmark, Poiseuille flow and two applications, one on sound wave propagation and another on fluid-flow through a simplified model of a rock matrix are finally shown.

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Pulsing Flows of a Viscous Incompressible Liquid in a Pipe with Elastic Walls

Psychology and Education Journal ◽

10.17762/pae.v58i2.2293 ◽

2021 ◽

Vol 58 (2) ◽

pp. 1436-1444

Author(s):

Navruzov Kuralbay Et al.

Keyword(s):

Fluid Flow ◽

Pulse Wave ◽

Pressure Distributions ◽

Pulsating Fluid Flow ◽

Synthetic Materials ◽

Flow Through ◽

Elastic Pipes ◽

Speed Of Propagation ◽

First Time ◽

Pulsating Fluid

As you know, the recent intensive introduction into practice of flexible pipelines made of polymer synthetic materials, pulsating fluid flow in elastic pipes is of great importance. As you know, the recent intensive introduction into practice of flexible pipelines made of polymer synthetic materials, pulsating fluid flow in elastic pipes is of great importance. By solving the problem, the necessary hydrodynamic parameters will be determined, such as pressure distributions, velocities, flow rates, the speed of propagation of the pulse wave pressure and their decay. For the first time in this article, a decrease in hydraulic resistance in a pulsating flow through pipes due to the elasticity of the wall will be determined. The dependence of the dimensionless value of the pressure pulse wave on the vibrational number was investigated .The speed of the pulse wave was compared with the speed of Moens-Korteweg , and significant differences were revealed between them occurring at lower values of the Womersley oscillatory parameter, at large values of which significant differences are not observed. The dependence of the reciprocal damping per wavelength on the vibrational number , was also investigated; it was shown that the damping is free at smaller values of the Womersley vibrational parameter, practically equal to zero, and at large values of which it asymptotically approaches unity.

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Antiheparin Activity of Human Serum and Platelet Factor 4

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649105 ◽

1973 ◽

Vol 30 (01) ◽

pp. 093-105 ◽

Cited By ~ 1

Author(s):

C.H.J Sear ◽

L Poller ◽

F.R.C Path

Keyword(s):

Molecular Weight ◽

Ionic Strength ◽

Blood Serum ◽

Whole Blood ◽

Platelet Rich Plasma ◽

Gel Filtration ◽

Normal Serum ◽

Platelet Factor ◽

Mean Values ◽

Antiheparin Activity

SummaryThe antiheparin activity of normal serum has been studied by comparing the antiheparin activities of sera obtained from normal whole blood, platelet-rich plasma and platelet-’free’ plasma with a purified platelet extract during differential isoelectric precipitation and by gel filtration chromatography.The mean values for the activity of PRP-serum and PFP-serum were 106% (S.D. 11) and 10% (S.D. 3) of untreated whole blood respectively. The activity of whole blood serum, PRP serum and whole blood serum plus platelet extract precipitated under identical physical conditions, i.e. pH 7.0, I =0.008, indicating that the activities of the three samples are probably associated with PF4. PF4 precipitated from human platelet extract at pH 4.0, but this is probably due to the difference in the two biochemical environments investigated, i.e. serum and platelet extract.The gel filtration experiments revealed striking similarities between the major antiheparin activities of serum and platelet extract. At physiological pH and ionic strength both activities were associated with high molecular weight material, but at physiological pH and elevated ionic strength both activities behaved as much smaller entities of molecular weight between 25,000 and 30,000 daltons and it seems very likely that both activities are associated with the same molecule, i.e. PF4.

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