scholarly journals THERMOCHEMICAL STUDY OF ACID-BASE REACTIONS IN AQUEOUS SOLUTION OF PYRIDOXINE

2020 ◽  
Vol 63 (6) ◽  
pp. 25-29
Author(s):  
Alexander I. Lytkin ◽  
Olga N. Krutova ◽  
Pavel D. Krutov ◽  
Victoriya V. Dudar ◽  
Elena Yu. Tyunina
Keyword(s):  
Ionic Strength ◽  
Confidence Interval ◽  
Thermal Effects ◽  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Background Electrolyte ◽  
The Body ◽  
Water Dissociation ◽  
Thermochemical Study ◽  
Acid Base

Vitamin B6 is one of the most important vitamins necessary for the life of living organisms. Vitamin B6, which in the body is represented by coenzyme forms - pyridoxal phosphate and pyridoxamine phosphate, is a part of more than 100 enzymes. As the object of study, we chose pyridoxine. The thermal effects of interaction of the solution of pyridoxine with solutions of nitric acid and potassium hydroxide at 298.15K and ionic strength values of 0.25; 0.5 and 0.75 against the background of electrolyte-supporting potassium nitrate were measured with direct calorimetric method. The measurements were carried out in a calorimeter with an isothermal shell equipped with a 60 cm3 reaction vessel and electric calibration at T = 298.15 ± 0.01 К and P = 100.5 ± 0.7 kPa and automatic recording of the temperature-time curve. Relative measurement error for heats of dissolution of a standard substance was -0.1-0.3%. Calculation of the equilibrium composition of the system taking into account processes a step dissociation and water dissociation was carried out according to the KEV program. The thermal effects of dissociation of pyridoxine in a standard solution were found by extrapolating the heats of stepwise dissociation at fixed values of ionic strength to zero ionic strength. Since the thermal effects of dilution were measured in three concentration ranges of KNO3, the number of experiments in each series was at least three. To calculate the confidence interval of the average value of DН the Student's criterion was taken at a confidence interval of 0.95. Standard thermodynamic characteristics (DrH°, DrG°, DrS°) of reactions of acid-base interaction in aqueous solutions of pyridoxine were calculated. With an increase in the background electrolyte concentration, the endothermicity of stepwise pyridoxine ionization processes increases.

scholarly journals THERMODYNAMIC CHARACTERISTICS OF ACID-CORE REACTIONS INTERACTIONS IN THE WATER SOLUTION PIRIDOXAL-5'-PHOSPHATE

2020 ◽  
Vol 63 (7) ◽  
pp. 10-14
Author(s):  
Alexander I. Lytkin ◽  
Olga N. Krutova ◽  
Ekaterina D. Krutova ◽  
Yuliya V. Mokhova ◽  
Elena Yu. Tyunina
Keyword(s):  
Confidence Interval ◽  
Thermal Effects ◽  
Water Solution ◽  
Thermodynamic Characteristics ◽  
Equilibrium Composition ◽  
Potassium Nitrate ◽  
Biologically Active ◽  
Water Dissociation ◽  
Time Curve ◽  
Step Dissociation

As the object of the study, we selected 3-hydroxy-2-methyl-5-(phosphonic) methyl-4-pyridincarboxaldehyde (pyridoxal-5'-phosphate) which is one of the most important biologically active compounds. Direct calorimetric method was used to measure the thermal effects of interaction of the solution of pyridoxal-5'-phosphate with solutions of nitric acid and potassium hydroxide at 298.15K and ionic strength values of 0.5; 1.0 and 1.5 against the background of electrolyte-supporting potassium nitrate. The measurements were carried out in a calorimeter with an isothermal shell equipped with a 60 cm3 reaction vessel and electric calibration at T = 298.15K ± 0.01 К and P = 100.5± 0.7 kPa and automatic recording of the temperature-time curve. Relative measurement error for heats of dissolution of a standard substance was -0.1-0.3%. Close values of constant sequencing of pyridosal-5'-phosphate do not allow to distinguish such an area of pH where only one of the processes of step dissociation would occur. In this regard the total thermal effect of protonation of pyridoxal-5'-phosphate would be measured. Calculation of the equilibrium composition of the system took into account processes step dissociation and water dissociation was carried out according to the KEV program. The thermal effects of stepwise dissociation of pyridoxal-5'-phosphate are calculated using the universal HEAT program. Because, the thermal effects of dilution were measured in three concentration ranges of KNO3: 0.4-0.5;0.9-1.0; 1.4-1.5 mol /l, the number of experiments in each series was at least four. To calculate the confidence interval of the average value of DН Student's criterion was taken at a confidence interval of 0.95 The standard thermal effects of stepwise ionization of pyridoxal-5'-phosphate were found by extrapolation of experimentally obtained amounts of piridoxyxal-5'-phosphate to zero ion force of the solution.

scholarly journals The Affinity of Carboplatin to B-Vitamins and Nucleobases

2021 ◽  
Vol 22 (7) ◽  
pp. 3634
Author(s):  
Beata Szefler ◽  
Przemysław Czeleń ◽  
Przemysław Krawczyk
Keyword(s):  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Antitumor Agents ◽  
Lone Pair ◽  
Chemical Compounds ◽  
Free Energies ◽  
Aromatic Rings ◽  
Anti Cancer ◽  
Potential Impact ◽  
Reactive Molecule

Platinum compounds have found wide application in the treatment of various types of cancer and carboplatin is one of the main platinum-based drugs used as antitumor agents. The anticancer activity of carboplatin arises from interacting with DNA and inducing programmed cell death. However, such interactions may occur with other chemical compounds, such as vitamins containing aromatic rings with lone-pair orbitals, which reduces the anti-cancer effect of carboplatin. The most important aspect of the conducted research was related to the evaluation of carboplatin affinity to vitamins from the B group and the potential impact of such interactions on the reduction of therapeutic capabilities of carboplatin in anticancer therapy. Realized computations, including estimation of Gibbs Free Energies, allowed for the identification of the most reactive molecule, namely vitamin B6 (pyridoxal phosphate). In this case, the computational estimations indicating carboplatin reactivity were confirmed by spectrophotometric measurements.

The highs and lows of electrolytes part 2: calcium, phosphate and magnesium

2021 ◽  
Vol 12 (1) ◽  
pp. 20-25
Author(s):  
Paula Anderson
Keyword(s):  
Critical Care ◽  
Calcium Phosphate ◽  
The Body ◽  
Cellular Functions ◽  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance ◽  
Critical Care Patients

There are six electrolytes that are important in maintaining homeostasis within the body. They play vital roles in regulating neurological, myocardial, muscular and cellular functions and are involved in fluid and acid–base balance. Recognising and treating electrolyte derangements is an important role for veterinary nurses especially in emergency and critical care patients. This series of two articles will discuss the physiology behind each of the six major electrolytes and discuss to monitor and treat any abnormalities.

Study on Thermal Analysis of the Shape of Improved Electric Cooker Liner Based on ANSYS Workbench

2014 ◽  
Vol 487 ◽  
pp. 568-571
Author(s):  
Yan Li Su ◽  
Lei Li ◽  
Wei Guo Han
Keyword(s):  
Thermal Analysis ◽  
Thermal Stress ◽  
Stress Analysis ◽  
Thermal Effects ◽  
The Body ◽  
Total Deformation ◽  
Ansys Workbench

In this paper, a comparative thermal analysis is carried out according to the bottom of HR-FD51 electric cooker liner about a large or small fillet. And then the thermal analysis results are applied to stress analysis as the body loads. The results show that it can reduce thermal stress and total deformation with a large fillet, thereby, improves the lifespan of electric cooker liner and thermal effects as well.

COMMITTEE ON NUTRITION

PEDIATRICS ◽  
1966 ◽  
Vol 38 (6) ◽  
pp. 1068-1076
Author(s):  
Keyword(s):  
Vitamin B6 ◽  
Pyridoxal Phosphate ◽  
Normal Population ◽  
Clinical Signs ◽  
Normal Activity ◽  
Limited Information ◽  
Adequate Intake ◽  
Time Data ◽  
Binding Properties ◽  
Adequate Diet

Because of the limited information available it is not possible to derive precise figures for daily requirements of vitamin B6 in infants and children at this time. Data currently available suggest that the daily need in childhood is 0.5 to 1.5 mg and in adolescence is 1.5 to 2 mg. The requirement in infancy is clearly related to protein intake and is 20µg/gm of dietary protein. Requirements of a few individuals will undoubtedly be higher than the estimates for the normal population. Some of these patients will manifest frank biochemical and clinical signs of deficiency which will usually be promptly reversed by administration of small additional amounts of pyridoxine. Another group of patients will require large amounts of the vitamin to balance the heritable alteration in binding properties of a specific apoenzyme requiring pyridoxal phosphate for normal activity. It would appear that most infants, children and adults will have little difficulty in achieving an adequate intake of vitamin B6 if they receive what is considered to be in other respects an adequate diet.

Respiratory Acidosis and Alkalosis

2017 ◽  
Author(s):  
Horacio J Adrogué ◽  
Nicolaos E Madias
Keyword(s):  
Carbonic Acid ◽  
Clinical Manifestations ◽  
Respiratory Acidosis ◽  
Respiratory Alkalosis ◽  
Body Fluids ◽  
The Body ◽  
Acid Base ◽  
Acid Base Equilibrium ◽  
Therapeutic Principles ◽  
The Impact

Respiratory acid-base disorders are those disturbances in acid-base equilibrium that are expressed by a primary change in CO2 tension (Pco2) and reflect primary changes in the body’s CO2 stores (i.e., carbonic acid). A primary increase in Pco2 (and a primary increase in the body’s CO2 stores) defines respiratory acidosis or primary hypercapnia and is characterized by acidification of the body fluids. By contrast, a primary decrease in Pco2 (and a primary decrease in the body’s CO2 stores) defines respiratory alkalosis or primary hypocapnia and is characterized by alkalinization of the body fluids. Primary changes in Pco2 elicit secondary physiologic changes in plasma [HCO3ˉ] that are directional and proportional to the primary changes and tend to minimize the impact on acidity. This review presents the pathophysiology, secondary physiologic response, causes, clinical manifestations, diagnosis, and therapeutic principles of respiratory acidosis and respiratory alkalosis.  This review contains 4 figures, 3 tables, and 59 references. Key words: Respiratory acidosis, respiratory alkalosis, primary hypercapnia, primary hypocapnia, hypoxemia, pseudorespiratory alkalosis

Role of peripheral chemoreceptors and central chemosensitivity in the regulation of respiration and circulation.

1982 ◽  
Vol 100 (1) ◽  
pp. 23-40 ◽  
Author(s):  
R G O'Regan ◽  
S Majcherczyk
Keyword(s):  
The Body ◽  
Ion Concentration ◽  
Regulation Of Respiration ◽  
Acid Base Balance ◽  
Acid Base ◽  
Vascular Effects ◽  
Peripheral Chemoreceptor ◽  
Hydrogen Ion Concentration ◽  
Central Chemosensitivity ◽  
Base Balance

Adjustments of respiration and circulation in response to alterations in the levels of oxygen, carbon dioxide and hydrogen ions in the body fluids are mediated by two distinct chemoreceptive elements, situated peripherally and centrally. The peripheral arterial chemoreceptors, located in the carotid and aortic bodies, are supplied with sensory fibres coursing in the sinus and aortic nerves, and also receive sympathetic and parasympathetic motor innervations. The carotid receptors, and some aortic receptors, are essential for the immediate ventilatory and arterial pressure increases during acute hypoxic hypoxaemia, and also make an important contribution to respiratory compensation for acute disturbances of acid-base balance. The vascular effects of peripheral chemoreceptor stimulation include coronary vasodilation and vasoconstriction in skeletal muscle and the splanchnic area. The bradycardia and peripheral vasoconstriction during carotid chemoreceptor stimulation can be lessened or reversed by effects arising from a concurrent hyperpnoea. Central chemoreceptive elements respond to changes in the hydrogen ion concentration in the interstitial fluid in the brain, and are chiefly responsible for ventilatory and circulatory adjustments during hypercapnia and chronic disturbances of acid-base balance. The proposal that the neurones responsible for central chemoreception are located superficially in the ventrolateral portion of the medulla oblongata is not universally accepted, mainly because of a lack of convincing morphological and electrophysiological evidence. Central chemosensitive structures can modify peripheral chemoreceptor responses by altering discharges in parasympathetic and sympathetic nerves supplying these receptors, and such modifications could be a factor contributing to ventilatory unresponsiveness in mild hypoxia. Conversely, peripheral chemoreceptor drive can modulate central chemosensitivity during hypercapnia.

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