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411 results on '"Ohulchanskyy, Tymish Y."'

53. Excretable, ultrasmall hexagonal NaGdF4:Yb50% Nanoparticles for bimodal imaging and radiosensitization

Author

Damasco, Jossana Abcede, primary, Ohulchanskyy, Tymish Y, additional, Mahajan, Supriya D, additional, Chen, Guanying, additional, Singh, Ajay, additional, Kutscher, Hilliard, additional, Huang, Haoyuan, additional, Turowski, Steven, additional, Spernyak, Joseph A, additional, Singh, Anurag, additional, Lovell, Jonathan F, additional, Seshadri, Mukund, additional, and Prasad, Paras, additional

Published
2021
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56. Macrophages Modulated by Red/NIR Light: Phagocytosis, Cytokines, Mitochondrial Activity, Ca2+ Influx, Membrane Depolarization and Viability.

Author

Golovynska, Iuliia, Stepanov, Yurii V., Golovynskyi, Sergii, Zhou, Ting, Stepanova, Liudmyla I., Garmanchuk, Liudmyla V., Ohulchanskyy, Tymish Y., and Qu, Junle

Subjects
PHOTOBIOMODULATION therapy, MACROPHAGES, PERITONEAL macrophages, MITOCHONDRIA, CYTOKINES, THERAPEUTICS
Abstract

Low‐level light therapy (LLLT) is emerging as a promising therapeutic approach to modulate the biochemical and molecular processes within living cells. LLLT is known to produce local and systemic effects; therefore, immune cells in local tissues or in the circulation are affected by light. However, this specific effect remains weakly explored. In this study, the effect of red (650 nm) and NIR (808 nm) light on phagocytosis (respiratory burst), cytokine expression, mitochondrial activity, ROS generation, Ca2+ influx and membrane depolarization in macrophages in vitro is investigated. Both the phagocytic capacity and adhesion of macrophages strongly (~2.5 times) increased in the first hours after exposure to light in a dose‐dependent manner. The light‐evoked upregulation of phagocytosis is found to be less efficient than the maximal pharmacologically induced enhancement of ~3.2 times. Also, red/NIR light reduces the production of pro‐inflammatory cytokines and activates the secretion of anti‐inflammatory cytokines by several times in activated macrophages. At the same time, the viability shows a biphasic dose response: it increases after irradiation with lower doses (0.3–1 J cm−2) and decreases after treatment with higher doses (18–30 J cm−2), which is apparently associated with the upregulation of ROS generation, followed by an increase in the mitochondrial activity. [ABSTRACT FROM AUTHOR]

Published
2022
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58. Excretable, ultrasmall hexagonal NaGdF4:Yb50% Nanoparticles for bimodal imaging and radiosensitization

Author

Damasco, Jossana Abcede, primary, Ohulchanskyy, Tymish Y, additional, Mahajan, Supriya D, additional, Chen, Guanying, additional, Singh, Ajay, additional, Kutscher, Hilliard, additional, Huang, Haoyuan, additional, Turowski, Steven, additional, Spernyak, Joseph A, additional, Singh, Anurag, additional, Lovell, Jonathan F, additional, Seshadri, Mukund, additional, and Prasad, Paras, additional

Published
2020
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59. Photoacoustic visualization of the fluence rate dependence of photodynamic therapy

Author

Gao, Rongkang, primary, Xu, Hao, additional, Liu, Liangjian, additional, Zhang, Ying, additional, Yin, Ting, additional, Zhou, Huichao, additional, Sun, Mingjian, additional, Chen, Ningbo, additional, Ren, Yaguang, additional, Chen, Tao, additional, Pan, Yinhao, additional, Zheng, Mingbin, additional, Ohulchanskyy, Tymish Y., additional, Zheng, Rongqin, additional, Cai, Lintao, additional, Song, Liang, additional, Qu, Junle, additional, and Liu, Chengbo, additional

Published
2020
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68. Label-Free Imaging of β-Amyloid Plaques and Photodynamic Degradation

Author

黄燕霞 Huang Yanxia, 许皓 Xu Hao, 栾萍 Luan Ping, OhulchanskyyTymishY Ohulchanskyy Tymish Y, and 屈军乐 Qu Junle

Subjects
β amyloid, Chemistry, Biophysics, Degradation (geology), Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Label free
Published
2020

69. LED-based portable light source for photodynamic therapy

Author

Chepurna, Oksana, primary, Grebinyk, Anna, additional, Petrushko, Yulia, additional, Prylutska, Svitlana, additional, Grebinyk, Sergii, additional, Yashchuk, Valeriy, additional, Matyshevska, Olga, additional, Ritter, Uwe, additional, Dandekar, Thomas, additional, Frohme, Marcus, additional, Qu, Junle, additional, and Ohulchanskyy, Tymish Y., additional

Published
2019
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75. Novel Hybrid Compound 4-[(E)-2-phenylethenesulfonamido]-N-hydroxybutanamide with Antimetastatic and Cytotoxic Action: Synthesis and Anticancer Screening

Author

Zborovskii, Yurii L., primary, Orysyk, Viktor V., additional, Golovynska, Iuliia, additional, Dzhus, Olena I., additional, Garmanchuk, Liudmyla V., additional, Stepanov, Yurii V., additional, Khranovska, Natalia, additional, Nehelia, Anatolii O., additional, Golovynskyi, Sergii, additional, Ohulchanskyy, Tymish Y., additional, Qu, Junle, additional, Orysyk, Svitlana I., additional, Pekhnyo, Vasyl I., additional, and Vovk, Myhaylo V., additional

Published
2019
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78. Noninvasive Temperature Measurement in Dental Materials Using Nd3+, Yb3+ Doped Nanoparticles Emitting in the Near Infrared Region.

Author

Yakovliev, Artem, Ohulchanskyy, Tymish Y., Ziniuk, Roman, Dias, Tereza, Wang, Xin, Xu, Hao, Chen, Guanying, Qu, Junle, and Gomes, Anderson S. L.

Subjects
*YTTERBIUM, *DENTAL materials, *FLUORESCENCE resonance energy transfer, *TEMPERATURE measurements, *DENTAL ceramics, *NANOPARTICLES, *RADIATIVE transitions
Abstract

In this work, the application of near infrared (NIR)‐emitting NaYbF4:1%Tm3+@NaLuF4:30%Nd3+ core–shell nanoparticles is reported for noninvasive probing and monitoring the temperature during photopolymerization of dental materials. When excited at 808 nm, the synthesized nanoparticles emit NIR photoluminescence (PL) with two distinctive peaks at 865 and 980 nm which correspond to radiative transitions from the doped Nd3+ and Yb3+ ions, respectively. Luminescence intensity ratio between these two bands is found to vary with temperature due to temperature‐dependent electronic excitation energy transfer between Nd3+ and Yb3+ ions at the core/shell interface. This finding allows luminescence ratiometric evaluation of the in situ temperature during photopolymerization of resin cement (doped with nanoparticles) in a veneer placement procedure. In addition, the NIR emission also enables PL imaging of the distribution of the adhesive under the veneer. The results highlight that rare‐earth ions–doped nanoparticles with both excitation and emission in the NIR spectral range are advantageous for both PL‐based nanothermometry and imaging due to the reduced attenuation of NIR light by dental ceramics. [ABSTRACT FROM AUTHOR]

Published
2020
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80. Morpho-Functional Characteristics of Bone Marrow Multipotent Mesenchymal Stromal Cells after Activation or Inhibition of Epidermal Growth Factor and Toll-Like Receptors or Treatment with DNA Intercalator Cisplatin

Author

Golovynska, Iuliia, primary, Kalmukova, Olesia, additional, Svitina, Hanna M., additional, Kyryk, Vitaliy M., additional, Shablii, Volodimir A., additional, Senchylo, Nataliya V., additional, Ostrovska, Galyna V., additional, Dzerzhinskyi, Mykola, additional, Stepanov, Yurii V., additional, Golovynskyi, Sergii, additional, Ohulchanskyy, Tymish Y., additional, Liu, Liwei, additional, Garmanchuk, Liudmila V., additional, and Qu, Junle, additional

Published
2018
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86. Dye-sensitized lanthanide-doped upconversion nanoparticles

Author

Wang, Xindong, Valiev, Rashid R., Ohulchanskyy, Tymish Y., Ågren, Hans, Yang, Chunhui, Chen, Guanying, Wang, Xindong, Valiev, Rashid R., Ohulchanskyy, Tymish Y., Ågren, Hans, Yang, Chunhui, and Chen, Guanying

Abstract

Lanthanide-doped upconversion nanoparticles (UCNPs) are promising for applications as wide as biological imaging, multimodal imaging, photodynamic therapy, volumetric displays, and solar cells. Yet, the weak and narrow absorption of lanthanide ions poses a fundamental limit of UCNPs to withhold their brightness, creating a long-standing hurdle for the field. Dye-sensitized UCNPs are emerging to address this performance-limiting problem, yielding up to thousands-fold brighter luminescence than conventional UCNPs without dye sensitization. In their configuration, organic dyes with spectrally broad and intense absorption are anchored to the surface of UCNPs to harvest the excitation light energy, which is then transferred via Forster and/or Dexter mechanisms across the organic/inorganic interface to the lanthanides incorporated in UCNPs (with or devoid of a shell) to empower efficient upconversion. This tutorial review highlights recent progress in the development of dye sensitized UCNPs, with an emphasis on the theory of energy transfer, the geometric classification of the dye sensitized core and core/shell nanocrystals, and their emerging photonic and biophotonic applications. Opportunities and challenges offered by dye sensitized UCNPs are also discussed., QC 20170815

Published
2017
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87. A core-multiple shell nanostructure enabling concurrent upconversion and quantum cutting for photon management

Author

Shao, Wei, Chen, Guanying, Ohulchanskyy, Tymish Y., Yang, Chunhui, Ågren, Hans, Prasad, Paras N., Shao, Wei, Chen, Guanying, Ohulchanskyy, Tymish Y., Yang, Chunhui, Ågren, Hans, and Prasad, Paras N.

Abstract

Photon management enables the manipulation of the number of input photons by conversion of two or more light quanta into one (upconversion) or vice versa (quantum cutting). Simultaneous realization of both these processes in a single unit provides unique opportunities of efficient utilization of photons throughout a broad spectral range. Yet, concurrent realization of these two parallel optical processes in one single unit remains elusive, limiting its impact on many existing or possible future applications such as for panchromatic photovoltaics. Here, we describe an epitaxial active core/inert shell/active shell/inert shell fluoride nanostructure to implement upconversion and quantum cutting within spatially confined and isolated rare-earth-doped active domains. The core area transforms infrared photons through trivalent erbium (Er3+) ions into three-and two-photon upconverted visible and near infrared luminescence, while the second shell domain splits an excitation photon into two near infrared photons through cooperative quantum cutting from one trivalent terbium ion (Tb3+) to two trivalent ytterbium ions (Yb3+). The inert layer in between the active domains is able to effectively suppress the destructive interference between upconversion and quantum cutting, while the outermost inert shell is able to eliminate surfacerelated quenching. This design enables the colloidal core/multishell nanoparticles to have an upconversion quantum yield of similar to 1.6%, and to have a luminescence yield of the quantum cutting process as high as similar to 130%. This work constitutes a solid step for flexible photon management in a single nanostructure, and has an implication for photonic applications beyond photovoltaics., QC 20170601

Published
2017
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88. Aqueous ferrofluid of magnetic nanoparticles: Fluorescence labeling and magnetophoretic control

Author

Sahoo, Yudhishthira, Furlani, Edward P., Goodarzi, Alireza, Prasad, Paras N., Swihart, Mark T., Ohulchanskyy, Tymish Y., and Kaur, Navjot

Subjects
Magnetite -- Chemical properties, Magnetite -- Magnetic properties, Aqueous solution reactions -- Research, Chemicals, plastics and rubber industries
Abstract

A method used for the preparation of a biocompatible ferrrofluid containing dye-functionalized magnetite nanoparticles that can serve as fluorescent markers is described. This method implies the surface functionalization of magnetic nanoparticles using citric acid to produce a stable aqueous dispersion and the subsequent binding of fluorescent dyes to the surface of the particles.

Published
2005

89. Bipolar Effects in Photovoltage of Metamorphic InAs/InGaAs/GaAs Quantum Dot Heterostructures: Characterization and Design Solutions for Light-Sensitive Devices

Author

Golovynskyi, Sergii, primary, Seravalli, Luca, additional, Datsenko, Oleksandr, additional, Kozak, Oleksii, additional, Kondratenko, Serhiy V., additional, Trevisi, Giovanna, additional, Frigeri, Paola, additional, Gombia, Enos, additional, Lavoryk, Sergii R., additional, Golovynska, Iuliia, additional, Ohulchanskyy, Tymish Y., additional, and Qu, Junle, additional

Published
2017
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91. Structural and Epimeric Isomers of HPPH [3-Devinyl 3-{1-(1-hexyloxy) ethyl}pyropheophorbide-a]: Effects on Uptake and Photodynamic Therapy of Cancer

Author

Saenz, Courtney, primary, Cheruku, Ravindra R., additional, Ohulchanskyy, Tymish Y., additional, Joshi, Penny, additional, Tabaczynski, Walter A., additional, Missert, Joseph R., additional, Chen, Yihui, additional, Pera, Paula, additional, Tracy, Erin, additional, Marko, Aimee, additional, Rohrbach, Daniel, additional, Sunar, Ulas, additional, Baumann, Heinz, additional, and Pandey, Ravindra K., additional

Published
2017
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98. Heteroatom substitution induced changes in excited-state photophysics and singlet oxygen generation in chalcogenoxanthylium dyes: effect of sulfur and selenium substitutions

Author

Ohulchanskyy, Tymish Y., Donelly, David J., Detty, Michael R., and Prasad, Paras N.

Subjects
Photochemistry -- Research, Sulfur -- Optical properties, Selenium compounds -- Optical properties, Chemicals, plastics and rubber industries
Abstract

Photophysical properties of a series of tetramethylrosamine dyes in which the xanthylium oxygen atom are replaced with sulfur or selenium are examined.

Published
2004

99. Singlet oxygen generation via two-photon excited FRET

Author

Ditchel, William R., Serin, Jason M., Edder, Carine, Frechet, Jean M. J., Matuszewski, Michael, Tan, Loon-Seng, Ohulchanskyy, Tymish Y., and Prasad, Paras N.

Subjects
Cross sections (Nuclear physics) -- Research, Chemical bonds -- Research, Chromophores -- Research, Chemistry
Abstract

A new approach in which donor chromophores capable of efficient two-photon absorption(TPA) are covalently attached to a central porphyrin acceptor is presented. This approach has the potential to enhance the effective TPA cross section of the porphyrin beyond what is available by direct modification and is also offers more versatility.

Published
2004

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