Marina N. Kirichenko

Dynamics of statistically confident particle sizes and concentrations in blood plasma obtained by the dynamic light scattering method

Abstract. The work is devoted to the study of sizes and concentrations of proteins, and their aggregates in blood plasma samples, using static and dynamic light scattering methods. A new approach is proposed based on multiple repetition of measurements of intensity size distribution and on counting the number of registrations of different sizes, which made it possible to obtain statistically confident particle sizes and concentrations in the blood plasma. It was revealed that statistically confident particle sizes in the blood plasma were stable during 30 h of observations, whereas the concentrations of particles of different sizes varied as a result of redistribution of material between them owing to the protein degradation processes.

Obtaining of hydrogen in acoustoplasma discharge in liquids

The paper shows, that a low-temperature plasma initiated in liquid media in interelectrode discharge gap is able to decompose hydrogen containing organic molecules resulting in obtaining gaseous products with volume part of hydrogen higher than 90% (up to gas chromatography data). Tentative assessments of energy efficiency, calculated with regard for hydrogen and feedstock heating value and energy consumption, have shown efficiency factor of 60-70%, depending on the source mixture composition. Theoretical model calculations of discharge current and voltage have been performed; the values are in good accordance with experimental data.

Effect of iron oxide nanoparticles on the concentration-versus-sizes relation of proteins in the blood plasma and serum, and in model solutions

The effect of iron (III) oxide nanoparticles produced in acoustoplasma discharge with cavitation on the concentration and the sizes of particles in model protein solutions, human blood serum and plasma samples is studied. Dynamic and static light scattering data on size and concentration of particles show that the nanoparticles addition to fibrinogen-thrombin system affects the course of enzymatic reaction. Interaction of nanoparticles with fibrinogen solution (before thrombin addition) does not significantly change the distribution of scattered light intensity on particle sizes. Comparison of the relations of particle sizes and their concentration for fibrinogen solution with and without nanoparticles shows an increase of the slope of size-concentration relation in a log-log scale, which indicates an increase in the concentration of small particles and decrease of big ones. For model solution of fibrinogen with thrombin, initially incubated with iron oxide nanoparticles, the slopes of the size-concentration relation equals to k = –(4.62±0.33) and slightly differs from the slope of the relation for fibrinogen-thrombin system without nanoparticles k=–(4.23±0.28). We believe that changes in the size-concentration relation indicate the interaction of nanoparticles with proteins, which results in gelation rate change.

Dynamic characteristics of electric discharge in liquid under ultrasonic cavitation

The characteristics of electrical discharges in liquid media under the influence of intense ultrasonic vibrations are investigated and the difference in dynamic characteristics of discharges before cavitation and after cavitation begins. The experiments carried out during this work made it possible to establish that in a liquid in an intense ultrasonic field above the cavitation threshold there exists a special form of an electric discharge characterized by volumetric luminescence in the entire space between the electrodes and the current-voltage characteristic inherent in an anomalous glow discharge in a gas.

Study of physical properties of metal oxide nanoparticles obtained in acoustoplasma discharge

Nanoparticles of tungsten, copper, iron, and zinc oxides were synthesized in acoustoplasma discharge. Their size distribution was studied by electron microscopy and laser correlation spectroscopy. Ultrasound was found to narrow significantly the size distribution width of zinc oxide nanoparticles. Water suspensions of zinc oxide nanoparticles showed photoluminescence in red and near infrared spectral ranges, which makes them a promising material for luminescent diagnostics of biological systems.

Luminescent properties of nanoparticles synthesized in electric discharge in liquid under ultrasonic cavitation

In this paper, differences in the luminescence intensity of nanoparticles of metal oxides synthesized in electric discharges in liquid media under the influence of intense ultrasonic vibrations prior to cavitation and after the start of cavitation regime have been studied. The increase in the luminescence intensity of nanoparticles obtained by ultrasonic cavitation can be explained by the formation of defects in oxide crystals under the influence of intense mechanical action. In the process of synthesis, the particles are exposed not only to the action of electromagnetic fields, but also to shock waves during the collapse of cavitation bubbles, which leads to the formation of defective valence structures and delocalization of electrons.

Study of the Interaction between Iron Oxide Nanoparticles, Produced in Acoustoplasma Discharge with Cavitation, and Blood Plasma Fibrinogen by Light Scattering Techniques

Interactions between iron oxide nanoparticles, produced in acoustoplasma discharge with cavitation, and blood plasma fibrinogen is studied in a model solution by dynamic light scattering. Depending on the storage time of the nanoparticles, their interaction with the protein shows different dynamics of the size distribution. However, the biological action of the nanoparticles is the same regardless of the storage time, i.e., they act as inhibitors of the reaction of fibrin gel formation.

Effect of decreasing glucose concentration in blood plasma after blood saturation with oxygen

It was experimentally detected that the glucose concentration in blood plasma decreases after venous blood saturation with oxygen (oxygenation process). This effect was recorded for several tens of donor blood samples using IME-DC (Germany) and Optium Omega (USA) portable glucometers, as well as an optical method using holographic sensors based on hydrogel polymer films, independent of the presence of oxygen in plasma. During blood oxygenation in the organism, glucose is redistributed between blood plasma and erythrocyte cytoplasm in favor of cytoplasm. The observed effect is explained by an increase in the electric field during blood oxygenation in lipids of the erythrocyte cytoplasmic membrane, which orients dipoles of asymmetric glucose molecules along the normal to the membrane surface. This results in erythrocytemembrane permeability asymmetry.

Power law relation between particle concentrations and their sizes in the blood plasma

This work is devoted to the investigation of sizes and concentrations of particles in blood plasma by dynamic light scattering (DLS). Blood plasma contains many different proteins and their aggregates, microparticles and vesicles. Their sizes, concentrations and shapes can give information about donors health. Our DLS study of blood plasma reveals unexpected dependence: with increasing of the particle sizes r (from 1 nm up to 1 μm), their concentrations decrease as r-4 (almost by 12 orders). We found also that such dependence was repeated for model solution of fibrinogen and thrombin with power coefficient is -3,6. We believe that this relation is a fundamental law of nature that shows interaction of proteins (and other substances) in biological liquids.

Appearance of an artifact peak in the particle size distribution measured by DLS at low concentrations

The dynamic light scattering (DLS) method allows the determination of the particle size distribution of suspensions. At high dilutions, an artifact peak appears in the size distribution, which does not correspond to actual particles, but is caused by crossing the scattering volume boundaries by individual particles. The parameters of this peak are analyzed, the causes of its appearance and its effect on determined particle sizes are studied.