26
|
Borisanova AO, Chernyshev AV, Malakhov VV. The structure of the muscular system in the planktonic larva of colonial Kamptozoa. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2012; 442:31-33. [PMID: 22427219 DOI: 10.1134/s0012496612010097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Indexed: 05/31/2023]
|
27
|
Orlova DY, Borisov VI, Kozhevnikov VS, Maltsev VP, Chernyshev AV. Distribution function approach to the study of the kinetics of IgM antibody binding to FcγRIIIb (CD16b) receptors on neutrophils by flow cytometry. J Theor Biol 2011; 290:1-6. [DOI: 10.1016/j.jtbi.2011.08.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 08/12/2011] [Accepted: 08/22/2011] [Indexed: 10/17/2022]
|
28
|
Orlova DY, Bártová E, Maltsev VP, Kozubek S, Chernyshev AV. A nonfitting method using a spatial sine window transform for inhomogeneous effective-diffusion measurements by FRAP. Biophys J 2011; 100:507-16. [PMID: 21244847 DOI: 10.1016/j.bpj.2010.11.080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2010] [Revised: 11/17/2010] [Accepted: 11/30/2010] [Indexed: 01/13/2023] Open
Abstract
Determining averaged effective diffusion constants from experimental measurements of fluorescent proteins in an inhomogeneous medium in the presence of ligand-receptor interactions poses problems of analytical tractability. Here, we introduced a nonfitting method to evaluate the averaged effective diffusion coefficient of a region of interest (which may include a whole nucleus) by mathematical processing of the entire cellular two-dimensional spatial pattern of recovered fluorescence. Spatially and temporally resolved measurements of protein transport inside cells were obtained using the fluorescence recovery after photobleaching technique. Two-dimensional images of fluorescence patterns were collected by laser-scanning confocal microscopy. The method was demonstrated by applying it to an estimation of the mobility of green fluorescent protein-tagged heterochromatin protein 1 in the nuclei of living mouse embryonic fibroblasts. This approach does not require the mathematical solution of a corresponding system of diffusion-reaction equations that is typical of conventional fluorescence recovery after photobleaching data processing, and is most useful for investigating highly inhomogeneous areas, such as cell nuclei, which contain many protein foci and chromatin domains.
Collapse
|
29
|
Chernyshev AV, Temereva EN. First report of diagonal musculature in phoronids (Lophophorata: Phoronida). DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2010; 433:264-267. [PMID: 20711873 DOI: 10.1134/s0012496610040083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Indexed: 05/29/2023]
|
30
|
Chernyshev AV, Magarlamov TY. The first data on the nervous system of hoplonemertean larvae (Nemertea, Hoplonemertea). DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2010; 430:48-50. [PMID: 20380180 DOI: 10.1134/s0012496610010163] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
31
|
Bykov AT, Chernyshev AV. [Sanatorium and spa treatment of patients with isolated and combined pathology of the cardiovascular system and metabolism]. VOPROSY KURORTOLOGII, FIZIOTERAPII, I LECHEBNOI FIZICHESKOI KULTURY 2010:48-50. [PMID: 20734872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The present study involved 720 patients with metabolic syndrome, diabetes mellitus, coronary heart disease, hypertensive disease, and various combinations of these conditions examined in the course of sanatorium and spa treatment. The patients received either traditional or modified therapy. The latter modality included climato-balneotherapy, hypoxytherapy, bioresonance therapy, and hypercapnotherapy supplemented by the intake of Arfazetin herbal tea, Magnerot tablets, and Chvizhepse mineral water. Results of the study indicate that the proposed combined treatment had more pronounced curative effect compared with traditional therapy in patients of all groups included in this study.
Collapse
|
32
|
Fortov VE, Vaulina OS, Petrov OF, Vasiliev MN, Gavrikov AV, Shakova IA, Vorona NA, Khrustalyov YV, Manohin AA, Chernyshev AV. Experimental study of the heat transport processes in dusty plasma fluid. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 75:026403. [PMID: 17358428 DOI: 10.1103/physreve.75.026403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Revised: 09/29/2006] [Indexed: 05/14/2023]
Abstract
The results are given of an experimental investigation of heat transport processes in fluid dusty structures in rf-discharge plasmas under different conditions: for discharge in argon, and for discharge in air under an action of electron beam. The analysis of steady-state and unsteady-state heat transfer is used to obtain the coefficients of thermal conductivity and thermal diffusivity under the assumption that the observed heat transport is associated with a thermal conduction in the dusty component of plasmas. The temperature dependence of these coefficients is obtained, which agrees qualitatively with the results of numerical simulation for simple monatomic liquids.
Collapse
|
33
|
Matsunaga T, Chernyshev AV, Chesnokov EN, Krasnoperov LN. In situ optical monitoring of RDX nanoparticles formation during rapid expansion of supercritical CO2 solutions. Phys Chem Chem Phys 2007; 9:5249-59. [DOI: 10.1039/b707833c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
34
|
Temereva EN, Malakhov VV, Chernyshev AV. Giant actinotroch, a larva of Phoronida from the South China Sea: the giant larva phenomenon. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2006; 410:410-3. [PMID: 17278850 DOI: 10.1134/s001249660605019x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
|
35
|
Yurkin MA, Semyanov KA, Tarasov PA, Chernyshev AV, Hoekstra AG, Maltsev VP. Experimental and theoretical study of light scattering by individual mature red blood cells by use of scanning flow cytometry and a discrete dipole approximation. APPLIED OPTICS 2005; 44:5249-56. [PMID: 16149348 DOI: 10.1364/ao.44.005249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Elastic light scattering by mature red blood cells (RBCs) was theoretically and experimentally analyzed by use of the discrete dipole approximation (DDA) and scanning flow cytometry (SFC), respectively. SFC permits measurement of the angular dependence of the light-scattering intensity (indicatrix) of single particles. A mature RBC is modeled as a biconcave disk in DDA simulations of light scattering. We have studied the effect of RBC orientation related to the direction of the light incident upon the indicatrix. Numerical calculations of indicatrices for several axis ratios and volumes of RBC have been carried out. Comparison of the simulated indicatrices and indicatrices measured by SFC showed good agreement, validating the biconcave disk model for a mature RBC. We simulated the light-scattering output signals from the SFC with the DDA for RBCs modeled as a disk-sphere and as an oblate spheroid. The biconcave disk, the disk-sphere, and the oblate spheroid models have been compared for two orientations, i.e., face-on and rim-on incidence, relative to the direction of the incident beam. Only the oblate spheroid model for rim-on incidence gives results similar to those of the rigorous biconcave disk model.
Collapse
|
36
|
Wiklund M, Nord O, Gothäll R, Chernyshev AV, Nygren PA, Hertz HM. Fluorescence-microscopy-based image analysis for analyte-dependent particle doublet detection in a single-step immunoagglutination assay. Anal Biochem 2005; 338:90-101. [PMID: 15707939 DOI: 10.1016/j.ab.2004.11.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2004] [Indexed: 10/26/2022]
Abstract
A novel fluorescence-microscopy-based image analysis method for classification of singlet and doublet latex particles is demonstrated and applied to a particle-based immunoagglutination assay for quantification of biomolecules in microliter-volume bulk samples. The image analysis method, verified by flow cytometric agglutination analysis, is based on a pattern recognition algorithm employing Gaussian-base-function fitting which allows robust identification and counting of singlets, doublets, and higher agglomerates of fluorescent microparticles. The immunoagglutination assay is experimentally modeled by a biotin-streptavidin interaction, with the goal of both theoretically and experimentally investigating the performance of a general immunoagglutination-based assay. For this purpose a theoretical model of the initial agglutination kinetics, based on particle diffusion combined with a steric factor determined by the level of specific and nonspecific agglutination, was developed. The theoretical model combined with the experimental data can be used to optimize an agglutination-based assay with regard to sensitivity and dynamic range and to estimate the affinity, receptor surface density, molecular and binding site sizes, and level of nonspecific binding that is present in the assay. The experimental results are in good agreement with the theoretical model, indicating the usefulness of the model for immunoagglutination assay optimization.
Collapse
|
37
|
Semyanov KA, Tarasov PA, Zharinov AE, Chernyshev AV, Hoekstra AG, Maltsev VP. Single-particle sizing from light scattering by spectral decomposition. APPLIED OPTICS 2004; 43:5110-5115. [PMID: 15468713 DOI: 10.1364/ao.43.005110] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A Fourier transform was applied to size an individual spherical particle from an angular light-scattering pattern. The position of the peak in the amplitude spectrum has a strong correlation with the particle size. A linear equation retrieved from regression analysis of theoretically simulated patterns provides a relation between the particle size and the location of the amplitude spectrum's peak. The equation can be successfully applied to characterize particles of size parameters that range from 8 to 180 (corresponding to particle sizes that range from 1.2 to 27.2 microm at a wavelength of 0.633 microm). The precision of particle sizing depends on the refractive index and reaches a value of 60 nm within refractive-index region from 1.35 to 1.70. We have analyzed four samples of polystyrene microspheres with mean diameters of 1.9, 2.6, 3.0, and 4.2 microm and a sample of isovolumetrically sphered erythrocytes with a scanning flow cytometer to compare the accuracy of our new method with that of others.
Collapse
|
38
|
Rakov AL, Chernyshev AV. [Change in carbohydrate metabolism during the acute period of traumatic disease]. VOENNO-MEDITSINSKII ZHURNAL 2004; 325:21-7. [PMID: 15471411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
|
39
|
Vaulina OS, Petrov OF, Fortov VE, Chernyshev AV, Gavrikov AV, Shakhova OA. Three-particle correlations in nonideal dusty plasma. PHYSICAL REVIEW LETTERS 2004; 93:035004. [PMID: 15323830 DOI: 10.1103/physrevlett.93.035004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2003] [Indexed: 05/24/2023]
Abstract
Results are given of experimental investigation of three-particle correlations for liquid plasma-dust structures formed in the electrode layer of a high-frequency capacitive discharge. The obtained three-particle correlation functions for experimental and numerical data are analyzed and compared with the superposition approximation. The forming of clusters of macroparticles in plasma-dust systems being analyzed is revealed.
Collapse
|
40
|
Fortov VE, Petrov OF, Molotkov VI, Poustylnik MY, Torchinsky VM, Khrapak AG, Chernyshev AV. Large-amplitude dust waves excited by the gas-dynamic impact in a dc glow discharge plasma. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:016402. [PMID: 14995720 DOI: 10.1103/physreve.69.016402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2003] [Indexed: 05/24/2023]
Abstract
A large-amplitude wave with two humps of dust density, separated by a dip was generated. To excite the wave in the dc glow discharge dusty plasma a gas-dynamic impact was used. The structure obtained had several interesting properties such as strong compression of dust in the humps, supersonic dust particles in the rarefaction zone, reconstruction of the initial dust configuration after the passing of the wave. The peculiarities of the phenomenon observed are discussed. The mechanism of generation and propagation for such kind of perturbation is proposed.
Collapse
|
41
|
Surovtsev IV, Yurkin MA, Shvalov AN, Nekrasov VM, Sivolobova GF, Grazhdantseva AA, Maltsev VP, Chernyshev AV. Kinetics of the initial stage of immunoagglutionation studied with the scanning flow cytometer. Colloids Surf B Biointerfaces 2003. [DOI: 10.1016/s0927-7765(03)00177-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
42
|
Chernyshev AV, Nomaru K, Petrov AK, Chesnokov EN, Gorelik SR, Kuibida LV, Akberdin RR, Kuroda H. Infrared Multiphoton Si Isotope Selective Dissociation of Phenyltrifluorosilane under Free Electron Laser Irradiation. J Phys Chem A 2003. [DOI: 10.1021/jp034214p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
43
|
Isaeva VV, Chernyshev AV, Shkuratov D. Quasi-fractal organization of the gastrovascular system of the jellyfish Aurelia aurita: order and chaos. DOKL BIOCHEM BIOPHYS 2001; 377:110-2. [PMID: 11712137 DOI: 10.1023/a:1011592009785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
44
|
Chernyshev AV, Isaeva VV, Presnov EV. [Comparative analysis of topological organization in Metazoa]. ZHURNAL OBSHCHEI BIOLOGII 2001; 62:49-56. [PMID: 11236590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Topological patterns in Metazoa, using previously elaborated methodology with employment of the genus of the surface (p) as topological invariant are considered. The term "density of the genus of the surface" is introduced. In sponges and in a lesser degree among Cnidaria and, Ctenophoria an increase of genus p up to indefinite high values and the shaping of topologically complicated quasifractal systems (irrigation system in sponges and gastro-vascular system in Radiata) are evident. In most Bilateria a stable topological pattern with open digestive tube is formed and subsequent topological complications of other systems may occur. Complicated topological patterns increasing the genus of the surface are evolved on the base of quasifractal systems: gut pockets in turbellaria, tracheal system in arthropods, bronchial system in birds, gills in bivalve mollusks, etc. Peculiarities of ordered and disordered topological patterns as well as topological origin of the increase of the genus of the surface are considered.
Collapse
|
45
|
Surovtsev IV, Razumov IA, Nekrasov VM, Shvalov AN, Soini JT, Maltsev VP, Petrov AK, Loktev VB, Chernyshev AV. Mathematical modeling the kinetics of cell distribution in the process of ligand-receptor binding. J Theor Biol 2000; 206:407-17. [PMID: 10988026 DOI: 10.1006/jtbi.2000.2136] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A statistical approach is presented to model the kinetics of cell distribution in the process of ligand-receptor binding on cell surfaces. The approach takes into account the variation of the amount of receptors on cells assuming the homogeneity of monovalent binding sites and ligand molecules. The analytical expressions for the kinetics of cell distribution have been derived in the reaction-limited approximation. In order to demonstrate the applicability of the mathematical model, the kinetics of binding the rabbit, anti-mouse IgG with Ig-receptors of the murine hybridoma cells has been measured. Anti-mouse IgG was labeled with fluorescein isothiocyanate (FITC). The kinetics of cell distribution on ligand-receptor complexes was observed during the reaction process by real-time measuring of the fluorescence and light-scattering traces of individual cells with the scanning flow cytometer. The experimental data were fitted by the mathematical model in order to obtain the binding rate constant and the initial cell distribution on the amount of receptors.
Collapse
|
46
|
Shvalov AN, Surovtsev IV, Chernyshev AV, Soini JT, Maltsev VP. Particle classification from light scattering with the scanning flow cytometer. CYTOMETRY 1999; 37:215-20. [PMID: 10520202 DOI: 10.1002/(sici)1097-0320(19991101)37:3<215::aid-cyto8>3.0.co;2-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND The differential light-scattering pattern, an indicatrix, provides the most complete characterization of the optical properties of a particle. Particle classification can be performed on the basis of particle parameters retrieved from the indicatrices. This classification extends the ability of flow cytometry in particle recognition. METHODS The scanning flow cytometer (SFC) permits an acquisition of traces of light scattering signals, i.e., native SFC traces, from single particles. The acquired native SFC traces are transformed into indicatrices. The performance of the SFC in measurements of indicatrices has been demonstrated for the following particles: lymphocytes, erythrocytes, polystyrene particles, and milk-fat particles. RESULTS The structure and profile of the indicatrix for each particle type have been found to be unique. Classification of polystyrene particles has been performed on the basis of the map formed by particle refractive index and size. The polystyrene particles were classified using this map into different size categories ranging from 1.4-7 microm, with a size deviation of 0.07 microm. CONCLUSIONS The method based on analysis of native SFC traces shows better performance in particle classification than the method based on the particle refractive index and size map. The classification performance of the SFC will be useful, for example, for particle sorting and particle identification, and with additional fluorescent measurements may have applications in multiparameter particle-based immunoassay.
Collapse
|
47
|
Shvalov AN, Soini JT, Chernyshev AV, Tarasov PA, Soini E, Maltsev VP. Light-scattering properties of individual erythrocytes. APPLIED OPTICS 1999; 38:230-5. [PMID: 18305608 DOI: 10.1364/ao.38.000230] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We have studied the light-scattering properties of human erythrocytes both experimentally and theoretically. In the experimental study measurements were performed with a Scanning Flow Cytometer (SFC). The SFC can measure the light-scattering pattern (indicatrix) of an individual particle over an angular range of 10-60 degrees. We have observed polymorphism in the measured set of indicatrices. To understand the reason for this polymorphism, we have made a theoretical study of the scattering properties of erythrocytes. The Wentzel-Kramer-Brillouin approximation has been employed to calculate indicatrices of individual erythrocytes in different orientations relative to the incident light beam. The indicatrices were calculated over an angular range of 15-35 degrees. A comparison of the experimentally measured and theoretically calculated indicatrices shows that the polymorphism is due mainly to the different orientation of the erythrocytes in the flow. The effect caused by the Poiseuille profile of the flow on an individual erythrocyte within the SFC cuvette capillary was studied theoretically by use of the Stokes approximation. Rotation of an erythrocyte was predicted by this theoretical analysis, and this prediction was further verified by comparison with experimental results.
Collapse
|
48
|
Soini JT, Chernyshev AV, Hänninen PE, Soini E, Maltsev VP. A new design of the flow cuvette and optical set-up for the scanning flow cytometer. CYTOMETRY 1998; 31:78-84. [PMID: 9482276 DOI: 10.1002/(sici)1097-0320(19980201)31:2<78::aid-cyto2>3.0.co;2-e] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We introduce a new design for the optical cuvette and a new optical lay-out for the Scanning Flow Cytometer (SFC) that permits measurement of the angular dependency of the scattered light from individual moving particles. The improved optical scheme of the SFC allows measurement of the angular scattering pattern of individual particles at polar angles from 10 degrees to 120 degrees with integration at azimuthal angles from 0 degrees to 360 degrees and with angular resolution of better than 0.5 degrees. The performance of the SFC is demonstrated using certified polystyrene particles as reference material The aim of this work is to develop a flow cytometer, which, by recording the entire light scattering pattern of individual biological particles, would provide more information about the particle structure than the ordinary wide angle, forward and side scattering concepts.
Collapse
|
49
|
Kamnev AA, Renou-Gonnord MF, Antonyuk LP, Colina M, Chernyshev AV, Frolov I, Ignatov VV. Spectroscopic characterization of the uptake of essential and xenobiotic metal cations in cells of the soil bacterium Azospirillum brasilense. BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 1997; 41:123-30. [PMID: 9043641 DOI: 10.1080/15216549700201121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The results of flame (FAAS) or graphite furnace atomic absorption spectrometric (GFAAS) analyses are presented and discussed on the accumulation of essential metals (Mg, Ca, Mn and Fe contained in the cultivation medium) and traces of each one of the conventionally xenobiotic elements from the group V, Co, Ni, Cu, Zn or Pb, added to the medium in concentrations (0.2 mM) which do not essentially suppress growth of the bacterial culture, in cells of the plant root-associated nitrogen-fixing bacterium Azospirillum brasilense. Along with the essential cations assimilated by the bacterium, Zn and Cu were found to effectively accumulate in the biomass from the environment. The uptake of Co and Ni was significantly less pronounced, whereas Pb and V appeared to be present in cells in much lower concentrations than in the cultivation medium evidently showing no tendency to be assimilated by azospirilla. The effect of the above xenobiotics on the uptake level of the four essential elements provided evidence that they may compete for the formation of biologically active complexes with substances of both intracellular and extracellular localization. The analytical data obtained are compared with Fourier transform infrared (FTIR) spectra of intact vacuum-dried bacterial cells grown in a standard medium and under the conditions of an increased metal uptake.
Collapse
|
50
|
Maltsev VP, Chernyshev AV, Sem'yanov KA, Soini E. Absolute real-time measurement of particle size distribution with the flying light-scattering indicatrix method. APPLIED OPTICS 1996; 35:3275-3280. [PMID: 21102713 DOI: 10.1364/ao.35.003275] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The flying light-scattering indicatrix (FLSI, angular dependency of the intensity of light scattered by a moving individual particle) method, based on a scanning flow cytometer (SFC) that permits measurement of individual particle characteristics from light-scattering data, has been used for the determination of size distribution of the following particles: polystyrene latex, milk fat, and spores (Penicillium levitum, Aspergillus pseudoglaucus). The optical system of the SPC and empirical equations provided absolute sizing at the rate of 50 particles/s. Size distributions obtained with the FLSI method and a best-fit procedure using Mie scattering theory have been compared.
Collapse
|