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Гармаш, Александр Александрович

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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.

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Гармаш

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Александр Александрович

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Tailoring Photoluminescence from Si-Based Nanocrystals Prepared by Pulsed Laser Ablation in He-N2 Gas Mixtures
(2020) Muratov, A. V.; Fronya, A. A.; Antonenko, S. V.; Kharin, A. Y.; Aleshchenko, Y. A.; Derzhavin, S. I.; Karpov, N. V.; Dombrovska, Y. I.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Timoshenko, V. Y.; Kabashin, A. V.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Алещенко, Юрий Анатольевич; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович; Тимошенко, Виктор Юрьевич; Кабашин, Андрей Викторович
Using methods of pulsed laser ablation from a silicon target in helium (He)-nitrogen (N2) gas mixtures maintained at reduced pressures (0.5-5 Torr), we fabricated substrate-supported silicon (Si) nanocrystal-based films exhibiting a strong photoluminescence (PL) emission, which depended on the He/N2 ratio. We show that, in the case of ablation in pure He gas, Si nanocrystals exhibit PL bands centered in the "red - near infrared" (maximum at 760 nm) and "green" (centered at 550 nm) spectral regions, which can be attributed to quantum-confined excitonic states in small Si nanocrystals and to local electronic states in amorphous silicon suboxide (a-SiOx) coating, respectively, while the addition of N2 leads to the generation of an intense "green-yellow" PL band centered at 580 nm. The origin of the latter band is attributed to a radiative recombination in amorphous oxynitride (a-SiNxOy) coating of Si nanocrystals. PL transients of Si nanocrystals with SiOx and a-SiNxOy coatings demonstrate nonexponential decays in the micro- and submicrosecond time scales with rates depending on nitrogen content in the mixture. After milling by ultrasound and dispersing in water, Si nanocrystals can be used as efficient non-toxic markers for bioimaging, while the observed spectral tailoring effect makes possible an adjustment of the PL emission of such markers to a concrete bioimaging task.
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THE ISSUE OF PRESERVING INTERICTAL ACTIVITYIN LONG-TERM EEG STUDIES OF EPILEPSY ВОПРОС СОХРАНЕНИЯ ИНТЕРИКТАЛЬНОИ АКТИВНОСТИ В ДЛИТЕЛЬНЫХ ЭЭГ-ИССЛЕДОВАНИЯХ ЭПИЛЕПСИИ
(2024) Gulyaev, S. A.; Klimanov, S. G.; Germashev, G. A.; Garmash, A. A.; Гуляев, Сергей Александрович; Климанов, Сергей Геннадиевич; Гармаш, Александр Александрович
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Photoluminescent Si-based nanocrystals prepared by pulsed laser ablation in low-pressure helium-nitrogen mixtures for biomedical applications
(2020) Kharin, A. Y.; Fronya, A. A.; Antonenko, S. V.; Karpov, N. V.; Derzhavin, S. I.; Dombrovska, Y. I.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Timoshenko, V. Y.; Kabashin, A. V.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович; Тимошенко, Виктор Юрьевич; Кабашин, Андрей Викторович
© 2020 SPIE.Nanocrystalline silicon (Si) films were synthesized by nanosecond laser ablation of crystalline Si targets in low-pressure helium (He) and nitrogen (N2) gas mixtures. Photoluminescence (PL) spectra of the prepared samples were found to depend on the He/N2 ratio in the gas mixture. The ablation pure He atmosphere allowed us to prepare Si nanocrystals (NCs) exhibiting a PL band in red-near-IR range, while samples prepared in the presence of N2 exhibited a strong PL band with maximum in the green-yellow region. Such a modification of PL properties can be explained by the presence of amorphous Si oxynitride (a-SiNxOy) on the surface of Si-NCs. Structural studies of the prepared samples by means of the scanning electron microscopy revealed different morphology for Si-NCs produced under different gas mixtures. After treating of the films by ultrasound and dispersing in water, Si-NCs can be used as novel biodegradable markers for bioimaging, while the observed spectral tailoring effect makes possible an adjustment of the PL emission of such markers to a concrete bioimaging task.
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Emission of CH∗ and C 2 ∗ during the high-temperature oxidation of propane in reflected shock waves
(2019) Tereza, A. M.; Smirnov, V. N.; Shumova, V. V.; Nazarova, N. V.; Vlasov, P. A.; Garmash, A. A.; Власов, Павел Александрович; Гармаш, Александр Александрович
© 2019 Published under licence by IOP Publishing Ltd. The autoignition of a stoichiometric propane-oxygen mixture diluted with argon was studied behind reflected shock waves in the temperature range of 1230-1700 K at the total concentration of [M] 50 ∼ 10 -5 mol/cm 3 . Emission signals from electronically excited CH∗ (at λ = 429 nm) and C 2 ∗ (at λ = 516 nm) radicals were recorded. It was found that the CH∗ and C 2 ∗ emission time profiles reached their maxima almost simultaneously over the entire temperature range covered. The temperature dependence of the ignition delay time measured from the time of reaching the maximum by the CH∗ emission signal was simulated within the framework of several published data kinetic mechanisms. It was found that, at temperatures below 1400 K, all the kinetic models tested predict ignition delay times severalfold longer than that experimentally observed. Using a sensitivity analysis to the reaction rate constants in the induction period, the main reactions that affect the ignition delay time were identified.
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An experimental and simulation study of the effect of acetone and propane additives on soot formation in acetylene pyrolysis behind reflected shock waves
(2019) Agafonov, G. L.; Smirnov, V. N.; Tereza, A. M.; Shumova, V. V.; Vlasov, P. A.; Garmash, A. A.; Власов, Павел Александрович; Гармаш, Александр Александрович
© 2019 Published under licence by IOP Publishing Ltd. Experimental investigations and detailed kinetic simulations of the formation of soot particles during pyrolysis of mixtures of acetylene with acetone and propane behind reflected shock waves are performed. Acetone and propane additives are found to substantially promote the process of soot formation as compared with that in acetylene-argon mixtures. Detailed kinetic simulations closely reproduce our own experimental results and published data. The kinetic model of soot formation is comprised of 4782 direct and reverse reactions involving 372 species. The predictive possibility of the kinetic model of soot formation is tested by describing the effect of acetone and propane additives to acetylene-argon mixtures on soot formation. All the kinetic parameters of the unified kinetic model are kept constant. The indicated additives enhance the soot yield because polyyne-dominated pathway of soot nucleation, characteristic of unseeded acetylene-argon mixtures, is augmented by the aromatic pathway, typical of most hydrocarbons.
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Bit error rate evaluation in high speed communication channels
(2019) Garmash, A. A.; Domozhakov, D. A.; Rannev, N. Y.; Гармаш, Александр Александрович
© 2019 Published under licence by IOP Publishing Ltd. This work offers calculate technique probability errors in transmitter - receiver path during the design phase with apply theory of probability elements, which is based on results of transient process modeling. As estimation, designed method was verified by comparison his results with computer experiment results. Implementation and using variants of represented algorithm are offered.
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Broadband push-pull power amplifier design methodology based on the GaN component base for high-performance nonlinear junction detectors
(2019) Klokov, V.; Kargin, N.; Garmash, A. A.; Guzniaeva, E.; Клоков, Владимир Александрович; Каргин, Николай Иванович; Гармаш, Александр Александрович; Гузняева, Екатерина Александровна
The paper presents a description of design methodology for wide-band push-pull large-signal power amplifier based on GaN transistor with an output power of more than 10 W for high-performance Nonlinear Junction Detectors, which allows achieving optimal convergence of the theoretical model in practice, as well as increasing the efficiency of the power amplifier while maintaining a linear gain characteristic.
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Morphology and photoluminescence properties of silicon nanoparticles deposited in helium-nitrogen mixtures maintained at low residual pressures
(2021) Fronya, A. A.; Antonenko, S. V.; Derzhavin, S. I.; Karpov, N. V.; Kharin, A. Yu.; Garmash, A. A.; Kargin, N. I.; Klimentov, S. M.; Timoshenko, V. Yu.; Kabashin, A. V.; Фроня, Анастасия Андреевна; Антоненко, Сергей Васильевич; Гармаш, Александр Александрович; Каргин, Николай Иванович; Климентов, Сергей Михайлович; Тимошенко, Виктор Юрьевич; Кабашин, Андрей Викторович
We elaborated a technique of pulsed laser ablation in gas mixtures (He-N2), maintained under residual pressures of 0.5-5 Torr to deposit silicon (Si)-based nanostructured films on a substrate. We show that the deposited films can exhibit strong photoluminescence (PL) emission with the position of peaks depending on the pressure of ambient gas and the ratio of gases in the mixture. Nanostructured films prepared in pure He gas exhibited a strong band in the infrared range (around 760 nm) and a weak band in the green range (550 nm), which were attributed to quantum-confined excitonic states in small Si nanocrystals and radiative transitions via the localized electronic states in silicon suboxide coating, respectively. In contrast, nanostructured films prepared in He-N2 mixtures exhibited more intense “green-yellow” PL band centered at 580 nm, which was attributed to a radiative recombination in amorphous oxynitride (a-SiNxOy) coating of Si nanocrystals. We also present a detailed analysis of morphology of nanostructures Si-based films prepared by laser ablation. Finally, we show that the nanocrystals can be removed from the substrate and milled by ultrasound to form aqueous solutions of colloidal Si nanopartiles. The fabricated Si-based nanocrystals present a promising object for theranostics, combining imaging functionality based on PL emission and a series of therapy functionalities (photo and radiofrequency hyperthermia, photodynamic therapy). © 2021 Institute of Physics Publishing. All rights reserved.
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Review of radiation technologies for the treatment of covid-19 coronavirus infection
(2021) Gameeva, E. V.; Sarapultseva, E. I.; Garmash, A. A.; Gromushkina, E. V.; Maksarova, D. D.; Сарапульцева, Елена Игоревна; Гармаш, Александр Александрович; Громушкина, Елена Вячеславовна; Максарова, Дарима Дамбаевна
© 2021 State Research Center, Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency. All rights reserved.Due to the long-term lack of effective pharmacological concepts, the situation with the spread of a new coronavirus infection in 2019 (COVID-19) has aroused interest in considering the possible use of radiation technologies, including historical reports on the treatment of patients with pneumonia using low-dose radiation therapy. A brief review of articles on clinical trials of radiation technologies in the fight against COVID-19 is conducted. The authors of most of the analyzed articles, as well as the authors of this review, conclude that the available scientific data do not justify clinical trials of low-dose radiation therapy for the treatment of COVID-19 pneumonia due to the unclear benefits and risks of mortality from radiation-induced diseases, including radiogenic cancer and diseases of the circulatory system.
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БАЗА РАЗМЕЧЕННЫХ ДАННЫХ ДЛЯ РЕШЕНИЯ ЗАДАЧ КЛАССИФИКАЦИИ EU-TIRADS, АВТОМАТИЧЕСКИХ ДЕТЕКЦИИ (ЛОКАЛИЗАЦИИ) И СЕГМЕНТАЦИИ УЗЛОВЫХ ОБРАЗОВАНИЙ ЩИТОВИДНОЙ ЖЕЛЕЗЫ
(НМИЦ эндокринологии, НИЯУ МИФИ, 2023) Захарова, С. М.; Манаев, А. В.; Трухин, А. А.; Гармаш, А. А.; Зайцев, К. С.; Султанова, Б. А.; Трошина, Е. А.; Мокрышева, Н. Г.; Гармаш, Александр Александрович; Зайцев, Константин Сергеевич
Узловые образования щитовидной железы встречаются у 40-60 % населения мира, в настоящее время одной из наиболее важных проблем остаётся операторозависимость метода ультразвуковой диагностики. Данная база данных состоит из серий ультразвуковых изображений (кинопетель, полученных в режиме Cine) продольных и поперченных проекций узловых образований щитовидной железы, серий размеченных областей узловых образований щитовидной железы. Данная база данных предназначена для обучения нейросетей и моделей машинного обучения в медицине по направлению ультразвуковой диагностики узловых образований щитовидной железы. Тип ЭВМ: IBM PC - совмест. ПК; ОС: Mac, Windows, Linux.