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Author | Tiulina, V.; Iomdina, E.; Goltsman, G.; Seliverstov, S.; Sianosyan, A.; Teplyakova, K.; Rusova, A.; Zaitsev, S.; Zernii, E.; Senin, I. | ||||
Title | UVB promotes the initiation of uveitic inflammatory and changes in thehydration of the cornea in vivo | Type | Miscellaneous | ||
Year | 2019 | Publication | FEBS Open Bio | Abbreviated Journal | FEBS Open Bio |
Volume | 9 | Issue | S1 | Pages | 79 |
Keywords | medicine; scheimpflug imaging; UVB; confocal microscopy; cornea; optical coherent tomography; rabbit eyes; terahertz radiation | ||||
Abstract | Recently, active research has been conducted in the field of terahertz (THz) scanning of human tissues for noninvasive determination of their hydration level, which haves hown high diagnostic efficiency of this technology in various pathological conditions. Recently, we have developed a laboratory model of the facility for monitoring the state of the water balance of the cornea using THz scanning in vivo, which opens up the possibility of applying this approach in ophthalmology. The aim of the work wasto compare the results of the THz scan of the cornea with its clinical changes using the example of an experimental model of the UV induced keratouveitis. Anexperimental study, which included a comprehensive assessment of clinical changes in the cornea of rabbits during keratouveitis induction, revealed a decrease in the stability of the tear film, pathological changes in the corneal epithelium and stroma, as well as its anatomical and optical parameters. Comparison of data obtained in the THz scan of the cornea with tears production, optical coherence tomography and confocal microscopy showed their consistency in all observation periods, which allows us to conclude that the developed laboratory setup works and the feasibility of further research to promote the corneal hydration evaluation technology in clinical practice. Acknowledgements: Research was funded by the RSF, grant number 161500255. | ||||
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ISSN | 2211-5463 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Poster P-01-040 | Approved | no | ||
Call Number | Serial | 1276 | |||
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Author | Shurakov, A.; Seliverstov, S.; Kaurova, N.; Finkel, M.; Voronov, B.; Goltsman, G. | ||||
Title | Input bandwidth of hot electron bolometer with spiral antenna | Type | Journal Article | ||
Year | 2012 | Publication | IEEE Trans. THz Sci. Technol. | Abbreviated Journal | IEEE Trans. THz Sci. Technol. |
Volume | 2 | Issue | 4 | Pages | 400-405 |
Keywords | NbN HEB bolometers bandwidth, log-spiral antenna | ||||
Abstract | We report the results of our study of the input bandwidth of hot electron bolometers (HEB) embedded into the planar log-spiral antenna. The sensitive element is made of the ultrathin superconducting NbN film patterned as a bridge at the feed of the antenna. The contacts between the antenna and a sensitive element are made from in situ deposited gold (i.e., deposited over NbN film without breaking vacuum), which gives high quality contacts and makes the response of the HEB at higher frequencies less affected by the RF loss. An accurate experimental spectroscopic procedure is demonstrated that leads to the confirmation of the wide ( 8 THz) bandwidth in this antenna coupled device. | ||||
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Series Volume | Series Issue | Edition | |||
ISSN | 2156-342X | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 1161 | |||
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Author | Iomdina, E. N.; Seliverstov, S.; Sianosyan, A.; Teplyakova, K.; Rusova, A.; Goltsman, G. | ||||
Title | The prospects of using the radiation for the assessment of corneal and scleral hydration | Type | Abstract | ||
Year | 2016 | Publication | Acta Ophthalmol. | Abbreviated Journal | Acta Ophthalmol. |
Volume | 94 | Issue | Pages | ||
Keywords | BWO, avalanche transit‐time diode, medicine, biology | ||||
Abstract | Purpose An adequate water balance (hydration extent) is one of the basic factors of normal eye function, including its external shells – the cornea and the sclera. THz systems creating images in reflected beams are likely to become ideal instruments of noninvasive testing of corneal and scleral hydration degree as THz radiation is highly sensitive to water content. The paper aims at studying the transmittance and reflectance spectra of the cornea and the sclera of rabbit and human eyes, as well as those of the whole rabbit eye, in the frequency range of 0.13–0.32 THz. Methods The experiments were carried out on 3 corneas and 3 rabbit scleras, 2 whole rabbit eyes, and 3 human healthy adult scleras using a specially developed THz system based on reliable and easy‐to‐use continuous wave sources: a backward‐wave oscillator and an avalanche transit‐time diode. Results The transmittance spectra of the cornea and the sclera and the dependence of the reflection coefficient of these tissues in THz range on water percentage content were determined. Comparison of the rabbit cornea hydrated from 73.2% to 76.3% concentration by mass demonstrated an approximately linear relationship between THz reflectivity and water concentration. The decrease of free water concentration by 1% leads to a drop of the reflectance coefficient by 13%. The parameters studied displayed noticeable differences between the sclera and the cornea of rabbits and between rabbit sclera and human sclera. Conclusions Preliminary results demonstrate that the proposed technique, based on continuous THz radiation, may be used to create a device for noninvasive testing of corneal and scleral hydration, which has good potential of wide‐scale practical application. The work was supported by the Russian Foundation of Basic Research (grant No.15‐29‐03843) |
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ISSN | 1755375X | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 1333 | |||
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Author | Iomdina, E. N.; Seliverstov, S. V.; Teplyakova, K. O.; Jani, E. V.; Pozdniakova, V. V.; Polyakova, O. N.; Goltsman, G. N. | ||||
Title | Terahertz scanning of the rabbit cornea with experimental UVB-induced damage: in vivo assessment of hydration and its verification | Type | Journal Article | ||
Year | 2021 | Publication | J. Biomed. Opt. | Abbreviated Journal | J. Biomed. Opt. |
Volume | 26 | Issue | 4 | Pages | |
Keywords | medicine; scheimpflug imaging; UVB; confocal microscopy; cornea; optical coherent tomography; rabbit eyes; terahertz radiation | ||||
Abstract | SIGNIFICANCE: Water content plays a vital role in the normally functioning visual system; even a minor disruption in the water balance may be harmful. Today, no direct method exists for corneal hydration assessment, while it could be instrumental in early diagnosis and control of a variety of eye diseases. The use of terahertz (THz) radiation, which is highly sensitive to water content, appears to be very promising. AIM: To find out how THz scanning parameters of corneal tissue measured by an experimental setup, specially developed for in vivo contactless estimations of corneal reflectivity coefficient (RC), are related to pathological changes in the cornea caused by B-band ultraviolet (UVB) exposure. APPROACH: The setup was tested on rabbit eyes in vivo. Prior to the course of UVB irradiation and 1, 5, and 30 days after it, a series of examinations of the corneal state was made. At the same time points, corneal hydration was assessed by measuring RC. RESULTS: The obtained data confirmed the negative impact of UVB irradiation course on the intensity of tear production and on the corneal thickness and optical parameters. A significant (1.8 times) increase in RC on the 5th day after the irradiation course, followed by a slight decrease on the 30th day after it was revealed. The RC increase measured 5 days after the UVB irradiation course generally corresponded to the increase (by a factor of 1.3) of tear production. RC increase occurred with the corneal edema, which was manifested by corneal thickening (by 18.2% in the middle area and 17.6% in corneal periphery) and an increased volume of corneal tissue (by 17.6%). CONCLUSIONS: Our results demonstrate that the proposed approach can be used for in vivo contactless estimation of the reflectivity of rabbit cornea in the THz range and, thereby, of cornea hydration. | ||||
Address | National Research University Higher School of Economics, Moscow Institute of Electronics and Mathema, Russia | ||||
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Language | English | Summary Language | Original Title | ||
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Series Volume | Series Issue | Edition | |||
ISSN | 1083-3668 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | PMID:33834684; PMCID:PMC8027227 | Approved | no | ||
Call Number | Serial | 1258 | |||
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Author | Iomdina, E. N.; Goltsman, G. N.; Seliverstov, S. V.; Sianosyan, A. A.; Teplyakova, K. O.; Rusova, A. A. | ||||
Title | Study of transmittance and reflectance spectra of the cornea and the sclera in the THz frequency range | Type | Journal Article | ||
Year | 2016 | Publication | J. Biomed. Opt. | Abbreviated Journal | J. Biomed. Opt. |
Volume | 21 | Issue | 9 | Pages | 97002 (1 to 5) |
Keywords | BWO, IMPATT diode, Schottky diode, medicine, animals, cornea, physiology, humans, rabbits, sclera diagnostic imaging, physiology | ||||
Abstract | An adequate water balance (hydration extent) is one of the basic factors of normal eye function, including its external shells: the cornea and the sclera. Adequate control of corneal and scleral hydration is very important for early diagnosis of a variety of eye diseases, stating indications for and contraindications against keratorefractive surgeries and the choice of contact lens correction solutions. THz systems of creating images in reflected beams are likely to become ideal instruments of noninvasive control of corneal and scleral hydration degrees. This paper reports on the results of a study involving transmittance and reflectance spectra for the cornea and the sclera of rabbit and human eyes, as well as those of the rabbit eye, in the frequency range of 0.13 to 0.32 THz. The dependence of the reflectance coefficient of these tissues on water mass percentage content was determined. The experiments were performed on three corneas, three rabbit scleras, two rabbit eyes, and three human scleras. The preliminary results demonstrate that the proposed technique, based on the use of a continuous THz radiation, may be utilized to create a device for noninvasive control of corneal and scleral hydration, which has clear potential of broad practical application. | ||||
Address | Moscow State Pedagogical University, Department of Physics, 29 Malaya Pirogovskaya Street, Moscow 119435, Russia | ||||
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Language | English | Summary Language | Original Title | ||
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ISSN | 1083-3668 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | PMID:27626901 | Approved | no | ||
Call Number | Serial | 1335 | |||
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Author | Gayduchenko, I. A.; Fedorov, G. E.; Moskotin, M. V.; Yagodkin, D. I.; Seliverstov, S. V.; Goltsman, G. N.; Yu Kuntsevich, A.; Rybin, M. G.; Obraztsova, E. D.; Leiman, V. G.; Shur, M. S.; Otsuji, T.; Ryzhii, V. I. | ||||
Title | Manifestation of plasmonic response in the detection of sub-terahertz radiation by graphene-based devices | Type | Journal Article | ||
Year | 2018 | Publication | Nanotechnol. | Abbreviated Journal | Nanotechnol. |
Volume | 29 | Issue | 24 | Pages | 245204 (1 to 8) |
Keywords | single layer graphene, graphene nanoribbons | ||||
Abstract | We report on the sub-terahertz (THz) (129-450 GHz) photoresponse of devices based on single layer graphene and graphene nanoribbons with asymmetric source and drain (vanadium and gold) contacts. Vanadium forms a barrier at the graphene interface, while gold forms an Ohmic contact. We find that at low temperatures (77 K) the detector responsivity rises with the increasing frequency of the incident sub-THz radiation. We interpret this result as a manifestation of a plasmonic effect in the devices with the relatively long plasmonic wavelengths. Graphene nanoribbon devices display a similar pattern, albeit with a lower responsivity. | ||||
Address | Physics Department, Moscow State University of Education, Moscow 119991, Russia. National Research Center 'Kurchatov Institute', 123182, Moscow, Russia | ||||
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ISSN | 0957-4484 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | PMID:29553479 | Approved | no | ||
Call Number | Serial | 1308 | |||
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Author | Galin, M. A.; Klushin, A. M.; Kurin, V. V.; Seliverstov, S. V.; Finkel, M. I.; Goltsman, G. N.; Müller, F.; Scheller, T.; Semenov, A. D. | ||||
Title | Towards local oscillators based on arrays of niobium Josephson junctions | Type | Journal Article | ||
Year | 2015 | Publication | Supercond. Sci. Technol. | Abbreviated Journal | Supercond. Sci. Technol. |
Volume | 28 | Issue | 5 | Pages | 055002 (1 to 7) |
Keywords | Josephson junction local oscillators, JJ LO | ||||
Abstract | Various applications in the field of terahertz technology are in urgent need of compact, wide-tunable solid-state continuous wave radiation sources with a moderate power. However, satisfactory solutions for the THz frequency range are scarce yet. Here we report on coherent radiation from a large planar array of Josephson junctions (JJs) in the frequency range between 0.1 and 0.3 THz. The external resonator providing the synchronization of JJ array is identified as a straight fragment of a single-strip-line containing the junctions themselves. We demonstrate a prototype of the quasioptical heterodyne receiver with the JJ array as a local oscillator and a hot-electron bolometer mixer. | ||||
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ISSN | 0953-2048 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 1347 | |||
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Author | Tretyakov, I. V.; Finkel, M. I.; Ryabchun, S. A.; Kardakova, A. I.; Seliverstov, S. V.; Petrenko, D. V.; Goltsman, G. N. | ||||
Title | Hot-electron bolometer mixers with in situ contacts | Type | Journal Article | ||
Year | 2014 | Publication | Radiophys. Quant. Electron. | Abbreviated Journal | Radiophys. Quant. Electron. |
Volume | 56 | Issue | 8-9 | Pages | 591-598 |
Keywords | HEB mixers | ||||
Abstract | We report on the latest achievements in the development of superconducting hot-electron bolometer (HEB) mixers for terahertz superheterodyne receivers. We consider application ranges of such receivers and requirements for the basic characteristics of the mixers. Main features of the mixers, such as noise temperature, gain bandwidth, noise bandwidth, and required local-oscillator power, have been improved significantly over the past few years due to intense research work, both in terms of the element fabrication quality and in terms of understanding of the physics of the processes occurring in the HEB mixers. Contacts between the superconducting bridge and the planar antenna play a key role in the mixer operation. Improvement of the quality of the contacts leads simultaneously to a decrease in the noise temperature and an increase in the gain bandwidth of a mixer. | ||||
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Series Volume | Series Issue | Edition | |||
ISSN | 0033-8443 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 1170 | |||
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Author | Seliverstov, S. V.; Anfertyev, V. A.; Tretyakov, I. V.; Ozheredov, I. A.; Solyankin, P. M.; Revin, L. S.; Vaks, V. L.; Rusova, A. A.; Goltsman, G. N.; Shkurinov, A. P. | ||||
Title | Terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser | Type | Journal Article | ||
Year | 2017 | Publication | Radiophys. Quant. Electron. | Abbreviated Journal | Radiophys. Quant. Electron. |
Volume | 60 | Issue | 7 | Pages | 518-524 |
Keywords | NbN HEB mixer, QCL | ||||
Abstract | We study characteristics of the laboratory prototype of a terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser. The results obtained demonstrate the possibility to use this receiver as a basis for creation of a high-sensitivity terahertz spectrometer, which can be used in many basic and practical applications. A significant advantage of this receiver will be the possibility of placing the mixer and heterodyne in the same cryostat, which will reduce the device dimensions considerably. The obtained experimental results are analyzed, and methods of optimizing the parameters of the receiver are proposed. | ||||
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ISSN | 0033-8443 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 1322 | |||
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Author | Tuchak, A. N.; Gol’tsman, G. N.; Kitaeva, G. K.; Penin, A. N.; Seliverstov, S. V.; Finkel, M. I.; Shepelev, A. V.; Yakunin, P. V. | ||||
Title | Generation of nanosecond terahertz pulses by the optical rectification method | Type | Journal Article | ||
Year | 2012 | Publication | JETP Lett. | Abbreviated Journal | JETP Lett. |
Volume | 96 | Issue | 2 | Pages | 94-97 |
Keywords | optical rectification, lithium niobate crystal | ||||
Abstract | The possibility of the generation of quasi-cw terahertz radiation by the optical rectification method for broad-band Fourier unlimited nanosecond laser pulses has been experimentally demonstrated. The broadband radiation of a LiF dye-center laser is used as a pump source of a nonlinear optical oscillator. The energy efficiency of terahertz optical frequency conversion in a periodically polarized lithium niobate crystal is 4 × 10−9 at a pump power density of 7 MW/cm2. | ||||
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Series Volume | Series Issue | Edition | |||
ISSN | 0021-3640 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 1377 | |||
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