Papers by Andrei Chernyshev
Cytometry Part A, May 22, 2023
International Journal of Energetic Materials and Chemical Propulsion, 2007
Nanoscale crystals of cyclotrimethylenetrinitramine (RDX) were produced by Rapid Expansion of Sup... more Nanoscale crystals of cyclotrimethylenetrinitramine (RDX) were produced by Rapid Expansion of Supercritical Solutions (RESS). The experiments were performed by expansion of supercritical solutions of RDX in carbon dioxide through sapphire nozzles (ID: 100 and 150 mm) at pressures of 15.0-29.5 MPa and temperatures of 343-348 K. Recrystallized particles were characterized by Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction, HPLC and melting point analysis. The process produced particles with a mean size in the range 110-220 nm and a narrow size distribution. The product was crystalline as determined by X-ray diffraction. The effect of process conditions (T, P, nozzle diameter) on the crystal size distribution was determined.
Cytometry Part A, 2017
Whereas modern automated blood cell analyzers measure the volume of individual red blood cells (R... more Whereas modern automated blood cell analyzers measure the volume of individual red blood cells (RBCs), leading to four RBC indices (mean corpuscular volume, MCV; mean corpuscular hemoglobin, MCH; mean corpuscular hemoglobin concentration, MCHC; red cell distribution width, and RDW), the RBC shape has not been assessed by clinical screening tools. We applied the scanning flow cytometer (SFC) for complete characterization of intact RBC morphology in terms of diameter, maximal and minimal thicknesses, volume, surface area, sphericity index, spontaneous curvature, hemoglobin concentration, and content. The above‐mentioned individual RBC characteristics were measured without fluorescent markers and other chemicals by a SFC equipped only with 660 nm laser for RBC illumination and single detector for measurement of angle‐resolved light scattering. The distributions over all RBC characteristics were constructed and processed statistically to form the novel 31 RBC indices for 22 donor sample...
Journal of Immunological Methods, 2015
Ultrasensitive Instrumentation for DNA Sequencing and Biochemical Diagnostics, Proceedings Of, 1995
A novel type of Scanning Flow Cytometer (SFC) has been developed for improving particle analysis ... more A novel type of Scanning Flow Cytometer (SFC) has been developed for improving particle analysis from light scattering data. The use of the SFC and the Flying Light Scattering Indicatrix (FLSI) method allows absolute measurement of the size and refractive index of spherical particles. The separation efficiency of the single particle analysis using FLSI method is verified measuring the size distribution of standard latex particles. It is shown that particles differed in size more than 1.2 micrometers can be separated by the FLSI method to different classes. In the second part of this paper the feasibility of a Pulsed Laser Flow Cytometer (PLFC) equipped by a pulsed nitrogen laser is tested for fluorometric analysis of human lymphocytes stained with FITC-labeled monoclonal antibodies. In addition the feasibility for the fluorescence measurement in time-resolved regime of the PLFC is analyzed from measurement of photon collection efficiency of scanning optical system.
Journal of Theoretical Biology, 2016
A novel molecular-kinetic model of Band 3 activation by Mg 2 þ is introduced. The model is verifi... more A novel molecular-kinetic model of Band 3 activation by Mg 2 þ is introduced. The model is verified experimentally with the use of a scanning flow cytometer. The association constant of Mg 2 þ with Band 3 is evaluated as 0.07 mM. The method developed allows quantitative control and optimization of MgSO 4 treatment. Results of the work are useful particularly for early detection of risk of hypoxia.
Physical Chemistry Chemical Physics, 2007
Nanoparticles of RDX (cyclotrimethylenetrinitramine) generated by RESS (rapid expansion of superc... more Nanoparticles of RDX (cyclotrimethylenetrinitramine) generated by RESS (rapid expansion of supercritical solutions) using supercritical CO 2 were characterized in situ by a pulsed laser light scattering imaging technique using a gated ICCD (intensified CCD) camera. The absolute sensitivity calibration was performed using Rayleigh light scattering from air as well as light scattering from standard polystyrene spheres. The size distribution functions of the particles formed in the RESS jet were determined using the calibrated sensitivity. The diameter of RDX particles formed at the pre-expansion pressure of 180 bar was 73 nm at the maximum of the size distribution function. Assuming that the particles near the nozzle consisted mainly of CO 2 and the size distribution was log-normal, the diameter of the particles near the nozzle (7.5 mm from the nozzle) at the distribution maximum was 3.3 mm at the pre-expansion pressure of 180 bar. The number densities of the particles in the RESS jet were determined by counting individual particles in the light scattering images. Based on the measured particle size distributions and the number density of particles along the RESS jet, the mechanism of particle formation in RESS is discussed. The homogeneous nucleation mechanism is rejected as it fails to explain the large particle size experimentally observed. Instead, a modified ''spray-drying'' mechanism is suggested. w Electronic supplementary information (ESI) available: Calibration of the sensitivity of the ICCD camera (Appendix A); evaluation of the index of refraction of polystyrene and RDX at 248 nm (Appendix B); the dilution by air entrainment estimated based on the temperature profile (Appendix C). See
Measurement of scattering properties of individual particles with a scanning flow cytometer
Background: Detection of human immunotoxicity is relevant to predictive and regulatory toxicology... more Background: Detection of human immunotoxicity is relevant to predictive and regulatory toxicology but is usually complex, while nodal steps may provide simple and suitable endpoints. NF-kB activation is both a promising therapeutic target and an important immunotoxicity endpoint. Conventional methods employed to determine nuclear translocation of NF-kB lack statistical robustness (microscopy) or the ability to discern heterogeneity within the sampled populations (Western blotting and gel shift assays). Previously, we developed an in vitro assay of immunotoxicity based on quantitative measurement by Multispectral Image-in-Flow Cytometry (MsIFC) of NF-kB translocation in a monocytic cell line. MsIFC combines the high image content information of microscopy with the high throughput and multiparametric analysis of flow cytometry which overcomes the aforementioned limitations of conventional assays. In this study, we have adapted and validated this assay for human peripheral whole-blood ...
Journal of Quantitative Spectroscopy and Radiative Transfer, 2017
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights Fast method to characterize single spheres in flow from light scattering patterns. Based on peak position and zero-frequency amplitude of power spectrum. Solution is unique in a limited range of refractive indices. Method is robust with respect to distortions of spherical shape in experiments. Provides framework to construct inverse algorithms for other experimental signals.
Journal of Applied Spectroscopy, 1996
A technique for in situ characterization of the RESS process (Rapid Expansion of Supercrit. Solns... more A technique for in situ characterization of the RESS process (Rapid Expansion of Supercrit. Solns.) was developed and applied to RDX nano-particles formation. The technique is based on the combination of laser scattering and time resolved imaging. An excimer laser (248 nm) was used in combination with a fast gated ICCD camera. Particle size distribution functions downstream the RESS jet were obtained for neat CO2 as well as for supercrit. solns. of RDX in CO2. Plausible particle growth mechanisms are discussed. [on SciFinder(R)]
Tsitologiia, 2012
We suggest a new theoretical method of the flow cytometry DNA histograms and apply it for Drosoph... more We suggest a new theoretical method of the flow cytometry DNA histograms and apply it for Drosophila melanogaster imaginal discs cells. The model gives a possibility to determine the proportions of cells in G1, G2 (M) and S cell cycle phases. We show that the precision of G1 and G2 (M) DNA content measurements is limited by the precision of device zero signal arrangement. The usage of calculated device zero and dividing cells as the DNA content standards may improve the precision of DNA content measurements. We also compared the precisions of different DNA content methods and draw the conclusion that the current precisions of different methods are similar and lie within 2-6% interval.
Controlling Tissue Optical Properties: Applications in Clinical Study, 2000
ABSTRACT
Doklady Physical Chemistry
Chemical Physics Letters, 1993
ABSTRACT
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Papers by Andrei Chernyshev