Персона:
Тимошенко, Виктор Юрьевич

Организационные подразделения

Организационная единица

Инженерно-физический институт биомедицины

Цель ИФИБ и стратегия развития – это подготовка высококвалифицированных кадров на базе передовых исследований и разработок новых перспективных методов и материалов в области инженерно-физической биомедицины. Занятие лидерских позиций в биомедицинских технологиях XXI века и внедрение их в образовательный процесс, что отвечает решению практикоориентированной задачи мирового уровня – диагностике и терапии на клеточном уровне социально-значимых заболеваний человека.

Фамилия

Тимошенко

Имя

Виктор Юрьевич

Полная страница элемента

Результаты поиска

Теперь показываю 1 - 10 из 74

Только метаданные
Reflectance Modification in Nanostructured Silicon Layers with Gradient Porosity
(2019) Mussabek, G. K.; Yermukhamed, D.; Suleimenova, Z. A.; Assilbayeva, R. B.; Zavestovskaya, I. N.; Timoshenko, V. Y.; Завестовская, Ирина Николаевна; Тимошенко, Виктор Юрьевич
A significant change in effective reflectance spectra of nanostructured porous silicon layers grown with different times of metal-assisted chemical etching is detected. The low reflectances at the level of 5-10% measured in the spectral range of 200-400 nm are explained by strong elastic scattering of light in combination with absorption in silicon nanostructures, while a reflectance increase in the range of 500-1800 nm, which is visually detected as a "white" layer appearance is associated with Mie scattering in silicon nanostructures with gradient porosity under conditions of weak optical absorption. The results obtained are discussed from the viewpoint of potential applications of "black" and "white" nanocrystalline silicon in photonics and sensorics.
Только метаданные
Proton magnetization relaxation in aqueous suspensions of composite silicon-iron nanoparticles for biomedical applications
(2021) Mironova, A. D.; Kharin, A. Yu.; Perepukhov, A. M.; Ischenko, A. A.; Kargina, Yu. V.; Timoshenko, V. Yu.; Тимошенко, Виктор Юрьевич
© 2021 Institute of Physics Publishing. All rights reserved.Silicon-iron composite nanoparticles produced by arc-discharge plasma ablation method were characterized by scanning electron microscopy, dynamic light scattering, X-ray fluorescence diffractometry, and the effect of iron content and size of the nanoparticles on hydrogen nuclei magnetization relaxation were investigated by nuclear magnetic resonance relaxometry. It was shown that increasing in iron content during the synthesis leads to distortion of the spherical shape of the nanoparticles and increasing of their mean sizes from 140 nm to 350 nm. Nonlinear dependence of the longitudinal and transverse relaxivities from iron content was demonstrated. Increase in the iron concentration above 2.5 at. % leads to reduction of the both relaxivities, which can be explained by nonuniform distribution of iron and formation of iron containing agglomerates. It was shown that transverse and longitudinal relaxivities of the nanoparticles in their aqueous solutions inversely proportional from their hydrodynamic diameters in the range of 100 - 300 nm. The possibilities of using composite silicon-iron nanoparticles for biomedical applications are discussed.
Только метаданные
Photo-induced cubic-to-hexagonal polytype transition in silicon nanowires
(2019) Rodichkina, S. P.; Belarouci, A.; Bezverkhyy, I.; Chassagnon, R.; Lysenko, V.; Timoshenko, V. Y.; Тимошенко, Виктор Юрьевич
© 2019 The Royal Society of Chemistry.Transformation of the crystalline lattice in silicon nanowires from cubic diamond (cub-Si) to hexagonal diamond (hex-Si) was observed under laser irradiation at intensities above 10 kW cm-2 (wavelength of 473 nm) by appearance of an additional peak in their Raman spectra in the range from 490 to 505 cm-1. Formation of the hex-Si phase in SiNWs is favoured by strong mechanical stresses caused by inhomogeneous photo-induced heating, which results in a singlet-doublet splitting of the Raman peaks for LO and TO phonons at about 517 and 510 cm-1, respectively. The estimated values of the photo-induced mechanical stresses and temperatures required for the polytype transformation in SiNWs correspond to those for bulk Si. The formation of the hex-Si phase in SiNWs is further illustrated by huge photoluminescence (PL) enhancement at laser intensities above 10 kW cm-2, which correlates with the appearance of the Raman peak at about 500 cm-1. The spectral position of the PL band at about 1.5 eV is close to the direct band gap transition in the stressed hex-Si.
Открытый доступ
Morphophysiological changes in the intact surface of rat skin under the application of silicon and gold nanoparticles
(2019) Kondratenko, E. I.; Lomteva, N. A.; Kasimova, S. K.; Yakovenkova, L. A.; Timoshenko, V. Yu.; Alykova, A. F.; Zavestovskaya, I. N.; Тимошенко, Виктор Юрьевич; Завестовская, Ирина Николаевна
© Published under licence by IOP Publishing Ltd.The effect of a course application of suspension of porous silicon and gold nanoparticles on the skin of female rats on the level of free radical oxidation and catalase activity in the skin homogenate was studied. MesoPSi samples were formed using the standard method of electrochemical etching of p-type c-Si wafers with a surface orientation of (100) and a specific resistance of 1-5 mOm x cm in a solution of hydrofluoric acid and ethanol (HF (50%): C2H5OH = 1: 1) at an etching current density of 60 mA / cm2 for 1 hour (45 minutes-hour). After this, mesoPSi films were separated from the silicon substrate by a short-term increase in the current density to 600 mA / cm2. Aqueous suspensions of porous silicon nanoparticles with sizes of the order of 100 nm were obtained by mechanical grinding of mesoporous silicon films in water. Aqueous suspensions of gold nanoparticles with an average size of 30-50 nm were obtained by laser ablation of gold targets in deionized water. A suspension of silicon and gold nanoparticles in physiological saline at a concentration of 0.2 mg / ml was applied once a day in the form of a thin layer on a shaved area of the skin of animals (interscapular region) and left to dry completely. Applications were carried out for 10 days. The studied silicon and gold nanoparticles did not change the initial content of malondialdehyde and catalase activity in the skin tissue but contributed to the activation of the rate of spontaneous lipid peroxidation.
Только метаданные
Bi-Modal Nonlinear Optical Contrast from Si Nanoparticles for Cancer Theranostics
(2019) Rogov, A.; Ryabchikov, Y. V.; Geloen, A.; Tishchenko, I.; Kharin, A. Y.; Lysenko, V.; Zavestovskaya, I. N.; Kabashin, A. V.; Timoshenko, V. Y.; Завестовская, Ирина Николаевна; Кабашин, Андрей Викторович; Тимошенко, Виктор Юрьевич
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Presenting a safe alternative to conventional compound quantum dots and other functional nanostructures, nanosilicon can offer a series of breakthrough hyperthermia-based therapies under near-infrared, radiofrequency, ultrasound, etc., excitation, but the size range to sensitize these therapies is typically too large (>10 nm) to enable efficient imaging functionality based on photoluminescence properties of quantum-confined excitonic states. Here, it is shown that large Si nanoparticles (NPs) are capable of providing two-photon excited luminescence (TPEL) and second harmonic generation (SHG) responses, much exceeding that of smaller Si NPs, which promises their use as probes for bi-modal nonlinear optical bioimaging. It is finally demonstrated that the combination of TPEL and SHG channels makes possible efficient tracing of both separated Si NPs and their aggregations in different cell compartments, while the resolution of such an approach is enough to obtain 3D images. The obtained bi-modal contrast provides lacking imaging functionality for large Si NPs and promises the development of novel cancer theranostic modalities on their basis.
Только метаданные
Photothermal effects and heat conduction in nanogranular silicon films
(2021) Kurbanova, B. A.; Utegulov, Z. N.; Mussabek, G. K.; Timoshenko, V. Y.; Lysenko, V.; Тимошенко, Виктор Юрьевич
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.We present results on the photothermal (PT) and heat conductive properties of nanogranu-lar silicon (Si) films synthesized by evaporation of colloidal droplets (drop-casting) of 100 ± 50 nm-sized crystalline Si nanoparticles (NP) deposited on glass substrates. Simulations of the absorbed light intensity and photo-induced temperature distribution across the Si NP films were carried out by using the Finite difference time domain (FDTD) and finite element mesh (FEM) modeling and the obtained data were compared with the local temperatures measured by micro-Raman spectroscopy and then was used for determining the heat conductivities k in the films of various thicknesses. The cubic-to-hexagonal phase transition in Si NP films caused by laser-induced heating was found to be heavily influenced by the film thickness and heat-conductive properties of glass substrate, on which the films were deposited. The k values in drop-casted Si nanogranular films were found to be in the range of lowest k of other types of nanostructurely voided Si films due to enhanced phonon scattering across inherently voided topology, weak NP-NP and NP-substrate interface bonding within nanogranular Si films.
Открытый доступ
Laser-Ablative Synthesis of Silicon–Iron Composite Nanoparticles for Theranostic Applications
(2023) Bubnov, A. A.; Belov, V. S.; Kargina, Yu. V.; Tikhonowski, G. V.; Popov, A. A.; Kharin, A. Yu.; Shestakov, M. V.; Klimentov, S. M.; Timoshenko, V. Y.; Белов, Владимир Сергеевич; Тихоновский, Глеб Валерьевич; Попов, Антон Александрович; Климентов, Сергей Михайлович; Тимошенко, Виктор Юрьевич; Бубнов, Александр Андреевич
The combination of photothermal and magnetic functionalities in one biocompatible nanoformulation forms an attractive basis for developing multifunctional agents for biomedical theranostics. Here, we report the fabrication of silicon-iron (Si-Fe) composite nanoparticles (NPs) for theranostic applications by using a method of femtosecond laser ablation in acetone from a mixed target combining silicon and iron. The NPs were then transferred to water for subsequent biological use. From structural analyses, it was shown that the formed Si-Fe NPs have a spherical shape and sizes ranging from 5 to 150 nm, with the presence of two characteristic maxima around 20 nm and 90 nm in the size distribution. They are mostly composed of silicon with the presence of a significant iron silicide content and iron oxide inclusions. Our studies also show that the NPs exhibit magnetic properties due to the presence of iron ions in their composition, which makes the formation of contrast in magnetic resonance imaging (MRI) possible, as it is verified by magnetic resonance relaxometry at the proton resonance frequency. In addition, the Si-Fe NPs are characterized by strong optical absorption in the window of relative transparency of bio-tissue (650-950 nm). Benefiting from such absorption, the Si-Fe NPs provide strong photoheating in their aqueous suspensions under continuous wave laser excitation at 808 nm. The NP-induced photoheating is described by a photothermal conversion efficiency of 33-42%, which is approximately 3.0-3.3 times larger than that for pure laser-synthesized Si NPs, and it is explained by the presence of iron silicide in the NP composition. Combining the strong photothermal effect and MRI functionality, the synthesized Si-Fe NPs promise a major advancement of modalities for cancer theranostics, including MRI-guided photothermal therapy and surgery.
Только метаданные
Effect of Silicate Additive on Structural and Electrical Properties of Germanium Nanowires Formed by Electrochemical Reduction from Aqueous Solutions
(2022) Eremina, A. S.; Gavrilin, I. M.; Pokryshkin, N. S.; Kharin, A. Y.; Kharin, A.Y.; Syuy, A. V.; Volkov, V. S.; Yakunin, V. G.; Bubenov, S. S.; Dorofeev, S. G.; Gavrilov, S. A.; Еремина, Анна Сергеевна; Тимошенко, Виктор Юрьевич
Layers of germanium (Ge) nanowires (NWs) on titanium foils were grown by metal-assisted electrochemical reduction of germanium oxide in aqueous electrolytes based on germanium oxide without and with addition of sodium silicate. Structural properties and composition of Ge NWs were studied by means of the scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy. When sodium silicate was added to the electrolyte, Ge NWs consisted of 1–2 at.% of silicon (Si) and exhibited smaller mean diameter and improved crystallinity. Additionally, samples of Ge NW films were prepared by ultrasonic removal of Ge NWs from titanium foils followed with redeposition on corundum substrates with platinum electrodes. The electrical conductivity of Ge NW films was studied at different temperatures from 25 to 300 °C and an effect of the silicon impurity on the thermally activated electrical conductivity was revealed. Furthermore, the electrical conductivity of Ge NW films on corundum substrates exhibited a strong sensor response on the presence of saturated vapors of different liquids (water, acetone, ethanol, and isopropanol) in air and the response was dependent on the presence of Si impurities in the nanowires. The results obtained indicate the possibility of controlling the structure and electrical properties of Ge NWs by introducing silicate additives during their formation, which is of interest for applications in printed electronics and molecular sensorics. © 2022 by the authors.
Только метаданные
Measurement of silicon nanoparticles temperature by raman spectroscopy
(2021) Alykova, A. F.; Grigoryeva, M. S.; Zavestovskaya, I. N.; Timoshenko, V. Yu.; Григорьева, Мария Сергеевна; Завестовская, Ирина Николаевна; Тимошенко, Виктор Юрьевич
© 2021 Journal of Biomedical Photonics & Engineering.The temperature of silicon nanoparticles under laser photo-induced heating is determined from the ratio of the intensities of the Stokes and anti-Stokes components of the Raman scattering. The obtained results of the dependence of nanoparticles temperature on the laser radiation intensity and the temperature dependence of the Raman line position may be used to determine the optimal regimes of photo-hyperthermia enhanced by silicon nanoparticles for cancer therapy.
Открытый доступ
ВОЗДЕЙСТВИЕ ХОЛОДНОЙ ПЛАЗМЫ ГАЗОВОГО РАЗРЯДА АТМОСФЕРНОГО ДАВЛЕНИЯ НА КЛЕТКИ + PARAMECIUM CAUDATUM ПРИ ИЗУЧЕНИИ АНТИОКСИДАНТНЫХ СВОЙСТВ МЕКСИДОЛА
(НИЯУ МИФИ, 2025) Абрашитов, Г. Н.; Груздев, Г. А.; Якунин, В. Г.; Савинов, В. П.; Карпухина, О. В.; Тимошенко, В. Ю.; Тимошенко, Виктор Юрьевич
Исследованы антиоксидантные цитопротекторные свойства мексидола при воздействии аргоновой и гелиевой газоразрядной холодной плазмы атмосферного давления на культуру клеток Paramecium caudatum. Установлено, что мексидол практически полностью устраняет негативные эффекты окислительного стресса после плазменного воздействия, сохраняя 100% численности клеток. Полученные данные о различных поведенческих реакциях клеток подтверждают практическую ценность использованных одноклеточных организмов в качестве модельных объектов для фармакологических и токсикологических исследований, а применение газоразрядной холодной плазмы позволяет исключить прямое окислительное действие пероксида водорода (стандартная модель окислительного стресса) на исследуемые препараты и повысить достоверность токсикологических исследований.