• Journal of Radiation Industry
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• v.17 no.3
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• pp.219-224
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• 2023

A high-efficiency underwater radiation monitoring system, HydroGamma, has been developed for detecting ¹³⁷Cs and ¹³¹I in the event of waterborne radiation contamination. The system consists of a 3-inch NaI (Tl) detector, solar panels for power supply, data acquisition and transmission modules, and batteries. HydroGamma also includes a ⁴⁰K calibration source for remote performance evaluation and energy calibration. In this study, some simulations and experiments were carried out to evaluate the minimum detectable activities (MDA) of HydroGamma. We installed the HydroGamma at Tapjeongho Lake in Nonsan-si and acquired background data since MDA is calculated based on the experimental background data. The results show that the minimum detectable activities for ¹³⁷Cs and ¹³¹I were 1.78Bq L^-1 and 1.81Bq L^-1, respectively even though the gamma rays emitted from ⁴⁰K(1,460 keV) affect the minimum detectable activities for them.

• 대한방사선방어학회:학술대회논문집
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• 2009.11a
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• pp.74-75
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• 2009

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.168-169
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• 2009

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• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.174-174
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• 2004

It is necessary to perform the radionuclide inventory assessment for the disposal of low and intermediate radioactive waste containers. The $\gamma$ nuclide analyzer can be used for the assessment of containers. However, if the radioactivity in the containers is extremely low or high, radionuclide inventory of the containers can not be evaluated properly. Also, gamma scanning method is time consuming and has economical burden to the utilities.(omitted)

• 대한방사선방어학회:학술대회논문집
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• 2009.11a
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• pp.42-43
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• 2009

• 대한방사선방어학회:학술대회논문집
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• 2011.11a
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• pp.212-213
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• 2011

The biological effects of low dose ionizing radiation (LDIR) remain insufficiently understood. We examined for the scientific evidence to show the biological effects of LDIR using radiation-sensitive immune cells. We found that Ikaros protein was responsed to low dose-dependent effects of gamma radiation in IM-9 B lymphocytes. Ikaros encodes zinc finger transcription factors that is important regulators of a hematopoietic stem cells (HSCs) progression to the B lymphoid lineage development, differentiation and proliferation. In this study, we observed that cell proliferation was enhanced from 10% to 20% by LDIR (0.05 Gy) in IM-9 B lymphocytes. The Ikaros protein was phosphorylated in its serine/threonine (S/T) region and decreased its DNA binding activity in the cells exposed to LDIR. We found that Ikaros phosphorylation was up-regulated by CK2/AKT pathway and the residues of ser-304 and ser-306 in Ikaros was phosphorylated by LDIR. We also observed that Ikaros protein was localized from the nucleus to the cytoplasm after LDIR and bound with Autotaxin (ENPP2, ATX) protein, stimulating proliferation, migration and survival of immune cells. In addition, we found that the lysoPLD activity of ATX was dependent on Ikaros-ATX binding activity. These results indicate that the Ikaros is an important regulator of immune activation. Therefore, we suggest that low dose ionizing radiation can be considered as a beneficial effects, stimulating the activation of immune cells.

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.152-153
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• 2009

• Journal of Radiation Protection and Research
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• v.26 no.4
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• pp.393-398
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• 2001

The non-combustible RI wastes disposed of in hospital every year emit ${\gamma}$-ray or ${\beta}$-ray but their activities are very low to the extent of background. Development of more simple methods is needed because the conventional detection methods are so ineffective and complex. In this study, to solve this problem, detection method using efficiency curve for ${\gamma}$-ray emitting radioactive wastes measurement is proposed and experimental detection efficiency equation is also determined through HPGe's standard specimen measurement. For ${\beta}$-emitting radioisotopes detection, new measurement method using detection efficiency estimated by Monte Carlo simulation and SBD measurements is also proposed. According to the results of this paper, the unknown activity of low-level radioactive wastes without LSC requiring the preparation of standard sample and measurement for standard source detection efficiency could be determined efficiently and simply about ${\pm}17%$ in errors by using the theoretical detection efficiency and the SBD measurement result.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.127-131
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• 2014

While searching for lactic acid bacteria that can restore aging-impaired immune responses, we isolated the Toll-like receptor (TLR) 2/NF-${\kappa}B$-activating strain Lactobacillus plantarum HY7712 from kimchi and investigated its immunomodulating effect in whole-body ${\gamma}$-irradiated mice. Exposure to HY7712 strongly activated NF-${\kappa}B$ signaling in RAW264.7 cells, but inhibited lipopolysaccharide-stimulated NF-${\kappa}B$ activation. Moreover, HY7712 protected against the downregulation of interferon (IFN)-${\gamma}$ and upregulation of interleukin (IL)-13 caused by ${\gamma}$-irradiation in mice. In mice, ${\gamma}$-irradiation impaired NK-cell activity against YAC-1 tumor cells, but following HY7712 exposure, the activity of NK cells was restored to 91.5% of the level measured in control mice (p < 0.05). These findings suggest that HY7712 activates the TLR2/NF-${\kappa}B$ signaling pathway and protects against the impairment of NK-cell activity caused by ${\gamma}$-irradiation or aging.

• Journal of Radiation Protection and Research
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• v.29 no.1
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• pp.9-15
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• 2004

Firstly, we compared the two staining techniques, Giemsa and Acridine orange, to determine micronuclei on samples of cultures of five healthy human peripheral blood lymphocytes after ${\gamma}-irradiation\;(^{137}Cs)$ in dose ranges of 0 to 800cGy. It was found that the Acridine orange staining method gives more reliable results than the usual Giemsa staining method in micronucleus tests. Moreover, the frequency of micronuclei in cytokinesis-blocked human B-lymphocytes was studied after in vitro irradiation in dose ranges of 0 to 50cGy. After setting and separating the B-lymphocytes, the frequency of radiation-induced micronuclei were observed as the end-point markers for the low-dose radiation dosimetry after staining with Giemsa and Acridine orange dyes. The micronuclei frequency in B-lymphocytes was significantly elevated from 10 to 30cGy ${\gamma}-irradiation$. The determination of micronuclei in B-lymphocytes after staining with Acridine orange was higher than that of Giemsa. The frequency of micronuclei in B-lymphocytes was observed to be at least two times higher than those of T-lymphocytes Giemsa in dose increasing. Therefore, the determination of low-dose radiation-induced micronuclei in B-lymphocytes after staining with Acridine orange is likely to have the greatest potential in the estimation of low dose radiation exposure.