Персона: Чириков, Сергей Николаевич
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Институт лазерных и плазменных технологий
Стратегическая цель Института ЛаПлаз – стать ведущей научной школой и ядром развития инноваций по лазерным, плазменным, радиационным и ускорительным технологиям, с уникальными образовательными программами, востребованными на российском и мировом рынке образовательных услуг.
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- ПубликацияТолько метаданныеThe Physical Nature of Mesoscopic Inhomogeneities in Highly Diluted Aqueous Suspensions of Protein Particles(2019) Bunkin, N. F.; Penkov, N. V.; Ignatiev, P. S.; Kozlov, V. A.; Shkirin, A. V.; Chirikov, S. N.; Шкирин, Алексей Владимирович; Чириков, Сергей НиколаевичThe dispersed composition of water samples prepared by the multiple-dilution technique has been investigated opto-physically using two laser diagnostics methods: dynamic light scattering and laser phase microscopy. We studied suspensions of antibodies (Ab) to the human interferon-gamma (IFN) in water with an initial concentration of 0.125 mg ml(-1) (5x10(14) mol cm(-3)), which were subjected to 12 successive 100-multiple volume dilutions (C12) in water. Individual antibodies and particles of about 300 nm in size, which can be considered as aggregates of individual antibodies, have been found in the initial suspensions. It turned out that some mesoparticles with a concentration on the order of 10(3) cm(-3) exist also in suspensions subjected to C12 dilution. These particles have a refractive index close to typical values of protein refractive indices. A possible explanation of the origin of particles with sizes on the order of several hundreds of nanometers, revealed in highly diluted suspensions, is proposed. On the one hand, some of these particles may be aggregates of antibodies from the initial suspension, which remained (due to the flotation effect) in the bulk of the liquid after dilutions. On the other hand, the appearance of solid contaminant particles at the same mesoscopic scale (i.e., on the order of several hundreds of nanometers) cannot be excluded in the dilution process.
- ПубликацияТолько метаданныеModeling the Kinetics of the Singlet Oxygen Effect in Aqueous Solutions of Proteins Exposed to Thermal and Laser Radiation(2022) Shkirin, A. V.; Chirikov, S. N.; Suyazov, N. V.; Reut, V. E.; Grigorieva, D. V.; Gorudko, I. V.; Bruskov, V. I.; Gudkov, S. V.; Шкирин, Алексей Владимирович; Чириков, Сергей НиколаевичA system of kinetic equations describing the changes in the concentration of reactive oxygen species (ROS) in aqueous solutions of proteins was obtained from the analysis of chemical reactions involving singlet oxygen. Applying the condition of the stationarity of the intermediate products to the system, we determined the functional dependence of the hydrogen peroxide concentration on the protein concentration under the action of thermal and laser radiation. An approximate analytical solution to the nonlinear system of differential equations that define the ROS concentration dynamics was found. For aqueous solutions of bovine serum albumin (BSA) and bovine gamma globulin (BGG), the orders and rate constants of the reactions describing the ROS conversions were determined by minimizing the sum of squared deviations of the functions found by solving both the static and dynamic problems from experimentally measured dependences. When solving the optimization problem, the Levenberg–Marquardt algorithm was used. © 2022 by the authors.
- ПубликацияТолько метаданныеApplication of Laser Polarimetric Scatterometry in the Study of Water-Based Multicomponent Bioorganic Systems on the Example of Cow Milk(2022) Shkirin, A. V.; Ignatenko, D. N.; Chirikov, S. N.; Vorobev, A. V.; Gudkov, S. V.; Шкирин, Алексей Владимирович; Чириков, Сергей НиколаевичAbstract: The applicability of laser polarimetric scatterometry in the analysis of the dispersed composition of water-based multicomponent bioorganic systems has been investigated experimentally using cow milk samples with different fat contents before and after dilution with water. It is shown that the procedure of volume dilution with water makes it possible to determine simultaneously the fat and casein contents in milk on the basis of the angular dependences of light scattering matrix. The empirical dependence of scattering-matrix elements on the fat percentage in milk is revealed. The size distributions of fat and casein particles in the investigated milk samples has been obtained by solving the inverse problem for the measured scattering matrices. © 2022, Allerton Press, Inc.
- ПубликацияТолько метаданныеDetection of Somatic Cells in Milk Using Laser Light Scattering(2024) Shkirin, A. V.; Chirikov, S. N.; Suyazov, N. V.; Astashev, M. E.; Шкирин, Алексей Владимирович; Чириков, Сергей Николаевич
- ПубликацияТолько метаданныеA Monoblock Light-Scattering Milk Fat Percentage and Somatic Cell Count Sensor for Use in Milking Systems(2023) Shkirin, A. V.; Astashev, M. E.; Ignatenko, D. N.; Chirikov, S. N.; Шкирин, Алексей Владимирович; Чириков, Сергей НиколаевичA monoblock light-scattering sensor, which is capable of measuring the fat content of milk and indicating the excess by which the somatic cell count (SCC) is over the permissible level, has been developed for installation in dairy systems. In order for the sensor to perform measurements when the milking machine is working in the “milk plug” mode, a flow-through unit is designed in the form of a pipe with a lateral cylindrical branch, in which milk accumulates so as to eliminate large bubbles and achieve continuity of the milk flow. The operation of the sensor is based on the registration of the angular intensity distribution of light scattered in the transparent cylindrical segment of the tube branch. A semiconductor laser with a wavelength of 650 nm is used as a light source for determining scattering in milk. The angular distribution of the scattered light intensity (scattering indicatrix) is recorded using an axial photodiode array. The fat content is determined by the average slope of the measured scattering indicatrix in the range of scattering angles 72–162В°. The SCC level is estimated from the relative deviation of the forward scatter intensity normalized to the backscatter intensity with respect to uninfected milk. The sensor has been tested on a Yolochka-type milking machine.
- ПубликацияТолько метаданныеFeatures of Light Scattering in Turbid Media As Modeled for Two-Component Emulsions(2024) Shkirin, A. V.; Suyazov, N. V.; Chirikov, S. N.; Chaikov, L. L.; Шкирин, Алексей Владимирович; Чириков, Сергей Николаевич
- ПубликацияТолько метаданныеAnalysis of fat and protein content in milk using laser polarimetric scatterometry(2021) Ignatenko, D. N.; Bunkin, N. F.; Astashev, M. E.; Gudkov, S. V.; Shkirin, A. V.; Chirikov, S. N.; Шкирин, Алексей Владимирович; Чириков, Сергей Николаевич© 2021 by the authors. Licensee MDPI, Basel, Switzerland.Monitoring the composition of milk products is an important factor in the management of dairy farms and industry. Information on the quantitative content of milk components is necessary to control milk quality, as well as to optimize dairy cow nutrition and diagnose their clinical condition. The content of fat and protein is considered the main criterion for determining the market value of milk. Increasing the efficiency of dairy production requires the use of inexpensive and compact devices that are capable of performing multicomponent analysis of milk both directly on the farm and in technological lines. We investigated the possibility of fast simultaneous determination of fat and protein content in milk by laser polarimetric scatterometry. The block-diagonal elements of the scattering matrix were measured for a series of commercially produced milk samples with the indicated fat percentage, which were diluted by volume with water. From the measured scattering matrices, the size distributions of fat droplets and casein aggregates were reconstructed. Using the size histograms, the content of fat and protein and protein-to-fat ratio in the studied milk samples are estimated.
- ПубликацияТолько метаданныеKinetics of the Light-Oxygen Effect in Aqueous Solutions of Proteins(2020) Suyazov, N. V.; Ivanov, V. E.; Gudkov, S. V.; Shkirin, A. V.; Chirikov, S. N.; Шкирин, Алексей Владимирович; Чириков, Сергей Николаевич© 2020, Allerton Press, Inc.Abstract: Molecular mechanisms of the participation of proteins in reactive oxygen species (ROS) generation resulting from the singlet-oxygen effect upon laser exposure in solutions of various proteins are considered. The kinetic equations describing ROS generation are derived, and their approximate general solution is found in the analytical form. By comparison of the found kinetic dependences with experimental data, orders and rate constants of corresponding chemical reactions are determined. An analysis of the results makes it possible to consider that fundamental mechanisms of ROS formation reactions in solutions of various proteins are identical.
- ПубликацияТолько метаданныеCharacteristics of Protein Aggregation and Flotation in Water and Alcohol-Water Mixture(2020) Bunkin, N. F.; Penkov, N. V.; Chaikov, L. L.; Ignatiev, P. S.; Shkirin, A. V.; Chirikov, S. N.; Шкирин, Алексей Владимирович; Чириков, Сергей Николаевич© 2020, Allerton Press, Inc.Abstract: Investigation of immunoglobulin (IgG) solutions with the concentration of 0.125 mg/mL shows that monomer IgG macromolecules ~10 nm in size form aggregates as large as ~300 nm in water and ~900 nm in the 36.7 vol % ethanol–water mixture (EWM). Shaking results in formation of floating-up bubbles in the solutions of both types. However, efficiency of immunoglobulin bubble flotation in water and EWM is substantially different. This difference can be caused by simultaneous action of two mechanisms for attachment of IgG particles (macromolecules or aggregates) to bubbles in aqueous solutions: direct attraction of IgG particles to the charged surface of a bubble and existence of ion-stabilized nanobubbles with a radius of ~100 nm capable of making up compound particles like nanobubbles–IgG macromolecules/IgG aggregates, which in turn serve as “spatial agents” for flotation of IgG particles on larger bubbles. In the EWM, attachment of IgG particles to floating-up bubbles is ineffective because of weak surface charge of macro- and microbubbles and absence of nanobubbles.
- ПубликацияОткрытый доступStudy of light-scattering properties of protein-containing microparticles with a small difference in refractive indices(2020) Savchenko, I. V.; Vasilievich, N. V.; Bunkin, N. F.; Chirikov, S. N.; Shkirin, A. V.; Konnova, A. S.; Чириков, Сергей Николаевич; Шкирин, Алексей Владимирович© Published under licence by IOP Publishing Ltd.The refractive indices of fodder yeast grown on oil paraffins (paprin) and natural gas (gaprin) were measured by phase microscopy. The scattering matrices of aqueous suspensions of paprin and gaprin are calculated within the framework of the model of spherically symmetric particles. The possibility of identifying the suspensions by their scattering matrices is analyzed for a small difference in the real parts of the refractive index. Experimental measurements of the light scattering matrices show that in the region of small values of the size parameter (≈ 1) the identification of paprin and gaprin can be based only on the difference in the shapes of the particles, and the difference in the refractive indices is manifested for the values of the size parameter greater than 3.