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Your search keyword '"Chuev, Mikhail A."' showing total 22 results
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22 results on '"Chuev, Mikhail A."'

19. Interpretation of the Mössbauer Spectra of the Magnetic Nanoparticles in Mouse Spleen.

Author

Chuev, Mikhail A., Cherepanov, Valery M., Deyev, Sergey M., Mischenko, Iliya N., Nikitin, Maxim P., Polikarpov, Mikhail A., and Panchenko, Vladislav Y.

Subjects
*MOSSBAUER spectroscopy, *SPECTRUM analysis, *NANOMEDICINE, *SPLEEN, *LABORATORY mice, *MAGNETIC fields, *STOCHASTIC analysis, *ANISOTROPY
Abstract

We have developed a stochastic model for description of relaxation effects in the system of homogeneously magnetized single-domain particles and applied the model to the analysis of Mössbauer spectra of magnetic nanoparticles (Chemicell ARA) and mouse spleen after i.v. injection into animals. We estimate that the fraction of exogenous iron in nanoparticles in the mouse spleen 3 months after injection was 0.27±0.03. The spectra of the residual nanoparticles in the spleen had almost the same isomer shift but smaller mean hyperfine magnetic field values indicating decrease in the magnetic anisotropy energy (size) of the particles compared to the initial ones in the course of biodegradation. Concentration of ferritin-like iron was about three-fold higher than that in the spleen of untreated animals showing ferritin-like forms in the mouse spleen. [ABSTRACT FROM AUTHOR]

Published
2010
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21. Biodegradation of Magnetic Nanoparticles in Rat Brain Studied by Mössbauer Spectroscopy.

Author

Polikarpov, Dmitry M., Gabbasov, Raul R., Cherepanov, Valery M., Chuev, Mikhail A., Korshunov, Victor A., Nikitin, Maxim P., Deyev, Sergey M., and Panchenko, Vladislav Y.

Subjects
MAGNETIC nanoparticles, MOSSBAUER spectroscopy, BRAIN physiology, COMPARATIVE studies, IRON compounds, MAGNETIC fluids, LABORATORY rats
Abstract

Superparamagnetic particles of Fe3O4 in ferrofluid were injected transcranially in the ventricle of the rat brain. At three months after the injection the rat was sacrificed and the brain was investigated by Mössbauer spectroscopy and histological Perls Prussian blue method. Histological examination demonstrated increased concentration of blue areas in parenchyma and on the dura mater of the brain of experimental rat in comparison with the brain of control rat, indicating appearance in the brain of some undegradable compound of iron. Mössbauer spectra showed the presence in the ferrofluid of both Fe3O4 nanoparticles and an additional chemical compound which contains ferric iron in the high-spin state. Comparison of the Mössbauer spectra of the ferrofluid, of the brain before injection and of the brain three months after injection shows that the Fe3O4 nanoparticles were removed from the brain in three months. At the same time this additional chemical compound does not decompose and remains in the brain intact. [ABSTRACT FROM AUTHOR]

Published
2013
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22. Structural, magnetic, and transport properties of quantum well GaAs/d-Mn/GaAs/InxGa1–xAs/GaAs heterostructures

Author

Chuev, Mikhail, Pashaev, Elhan, Koval'chuk, Mikhail, Kvardakov, Vladimir, Subbotin, Ilia, and Likhachev, Igor

Abstract

The results of high-resolution X-ray diffraction and X-ray glancing-incidence mirror reflection studies of structural characteristics of the GaAs/Ga1–xInxAs/GaAs diluted magnetic semiconductors, with an Mn d-layer well separated from the Ga1–xInxAs quantum by the GaAs spacer, are presented. A strong correlation between the structural, magnetic, electro-physical and optical properties of the samples gives evidence that the samples consist of a distribution of ferromagnetic and paramagnetic regions. Such a phase separation can be understood by a non-random distribution of the local magnetic moments and fluctuations of the exchange interaction in the samples having semiconductor-type conductivity.

Published
2009
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