• Title/Summary/Keyword: radiation physics

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MEVVA ion Source And Filtered Thin-Film Deposition System

  • Liu, A.D.;Zhang, H.X.;Zhang, T.H.;Zhang, X.Y.;Wu, X.Y.;Zhang, S.J.;Li, Q.
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.2
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    • pp.55-57
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    • 2002

  • Metal-vapor-vacuum-arc ion source is an ideal source for both high current metal ion implanter and high current plasma thin-film deposition systems. It uses the direct evaporation of metal from surface of cathode by vacuum arc to produce a very high flux of ion plasmas. The MEVVA ion source, the high-current metal-ion implanter and high-current magnetic-field-filtered plasma thin-film deposition systems developed in Beijing Normal University are introduced in this paper.

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Review of Shielding Evaluation Methodology for Facilities Using kV Energy Radiation Generating Devices Based on the NCRP-49 Report

  • Na Hye Kwon;Hye Sung Park;Taehwan Kim;Sang Rok Kim;Kum Bae Kim;Jin Sung Kim;Sang Hyoun Choi;Dong Wook Kim
    • Progress in Medical Physics
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    • v.33 no.4
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    • pp.53-62
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    • 2022

  • In this study, we have investigated the shielding evaluation methodology for facilities using kV energy generators. We have collected and analysis of safety evaluation criteria and methodology for overseas facilities using radiation generators. And we investigated the current status of shielding evaluation of domestic industrial radiation generators. According to the statistical data from the Radiation Safety Information System, as of 2022, a total of 7,679 organizations are using radiation generating devices. Among them, 6,299 facilities use these devices for industrial purposes, which accounts for a considerable portion of radiation. The organizations that use these devices evaluate whether the exposure dose for workers and frequent visitors is suitable as per the limit regulated by the Nuclear Safety Act. Moreover, during this process, the safety shields are evaluated at the facilities that use the radiation generating devices. However, the facilities that use radiating devices having energy less than or equal to 6 MV for industrial purposes are still mostly evaluated and analyzed according to the National Council on Radiation Protection and Measurements 49 (NCRP 49) report published in 1976. We have investigated the technical standards of safety management, including the maximum permissible dose and parameters assessment criteria for facilities using radiation generating devices, based on the NCRP 49 and the American National Standards Institute/Health Physics Society N.43.3 reports, which are the representative reports related to radiation shielding management cases overseas.

  • https://doi.org/10.14316/pmp.2022.33.4.53 인용 PDF KSCI

Telomere-Mitochondrion Links Contribute to Induction of Senescence in MCF-7 Cells after Carbon-Ion Irradiation

  • Miao, Guo-Ying;Zhou, Xin;Zhang, Xin;Xie, Yi;Sun, Chao;Liu, Yang;Gan, Lu;Zhang, Hong
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.1993-1998
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    • 2016

  • The effects of carbon-ion irradiation on cancer cell telomere function have not been comprehensively studied. In our previous report cancer cells with telomere dysfunction were more sensitive to carbon-ion irradiation, but the underlying mechanisms remained unclear. Here we found that telomerase activity was suppressed by carbon-ion irradiation via hTERT down-regulation. Inhibition of telomere activity by MST-312 further increased cancer cell radiosensitivity to carbon-ion radiation. hTERT suppression caused by either carbon-ion irradiation or MST-312 impaired mitochondrial function, as indicated by decreased membrane potential, mtDNA copy number, mitochondrial mass, total ATP levels and elevated reactive oxygen species (ROS). PGC-$1{\alpha}$ expression was repressed after carbion-ion irradiation, and hTERT inhibition by MST-312 could further exacerbate this effect. Lowering the mitochondrial ROS level by MitoTEMPO could partially counteract the induction of cellular senescence induced by carbon-ion radiation and MST-312 incubation. Taken together, the current data suggest that telomere-mitochondrion links play a role in the induction of senescence in MCF-7 cells after carbon-ion irradiation.

  • https://doi.org/10.7314/APJCP.2016.17.4.1993 인용 PDF KSCI