• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.174-175
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• 2009

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• Molecular & Cellular Toxicology
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• v.5 no.2
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• pp.165-171
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• 2009

Biomarkers indicating past exposure to radiation have not yet been entirely satisfactory. In this study, we validated several genes reported as radiation response genes, as biomarkers to detect past exposure to radiation in occupationally exposed workers, especially workers in the medical field. A total of 54 radiation workers in hospital were investigated for radiation exposure dose. Their average radiation dose of recent one year was 1.09 mSv ($\pm$1.63) with a 10.63 mSv ($\pm$12.91) cumulative dose. The results of the multiple regression analysis for the various variables indicate that the Hsc70 (P=0.0292) and ORAL (P=0.0045) may be candidate biomarkers for the recent 1 year radiation exposure in radiation workers, whereas AEN (P=0.0334) and PGAMI (P=0.0003) might be for cumulative exposure.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1589-1599
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• 2017

Field programmable gate arrays (FPGAs) are getting more attention in safety-related and safety-critical application development of nuclear power plant instrumentation and control systems. The high logic density and advancements in architectural features make static random access memory (SRAM)-based FPGAs suitable for complex design implementations. Devices deployed in the nuclear environment face radiation particle strike that causes transient and permanent failures. The major reasons for failures are total ionization dose effects, displacement damage dose effects, and single event effects. Different from the case of space applications, soft errors are the major concern in terrestrial applications. In this article, a review of radiation effects on FPGAs is presented, especially soft errors in SRAM-based FPGAs. Single event upset (SEU) shows a high probability of error in the dependable application development in FPGAs. This survey covers the main sources of radiation and its effects on FPGAs, with emphasis on SEUs as well as on the measurement of radiation upset sensitivity and irradiation experimental results at various facilities. This article also presents a comparison between the major SEU mitigation techniques in the configuration memory and user logics of SRAM-based FPGAs.

• Journal of Environmental Health Sciences
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• v.49 no.1
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• pp.1-10
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• 2023

Low-dose radiation exposure has received considerable attention because it reflects the general public's type and level of exposure. Still, controversy remains due to the relatively unclear results and uncertainty in risk estimation compared to high-dose radiation. However, recent epidemiological studies report direct evidence of health effects for various types of low-dose radiation exposure. In particular, international nuclear workers' studies, CT exposure studies, and children's cancer studies on natural radiation showed significantly increased cancer risk among the study populations despite their low-dose radiation exposure. These studies showed similar results even when the cumulative radiation dose was limited to an exposure group of less than 100 mGy, demonstrating that the observed excess risk was not affected by high exposure. A linear dose-response relationship between radiation exposure and cancer incidence has been observed, even at the low-dose interval. These recent epidemiological studies include relatively large populations, and findings are broadly consistent with previous studies on Japanese atomic bomb survivors. However, the health effects of low-dose radiation are assumed to be small compared to the risks that may arise from other lifestyle factors; therefore, the benefits of radiation use should be considered at the individual level through a balanced interpretation. Further low-dose radiation studies are essential to accurately determining the benefits and risks of radiation.

• Advances in nano research
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• v.16 no.6
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• pp.579-591
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• 2024

This study explained the effects of radiation, magnetic field, and nanoparticle shape on the peristaltic flow of an Upper-Convected Maxwell nanofluid through a porous medium in an asymmetric channel for a better understanding of cooling and heating mechanisms in the presence of magnetic fields. These phenomena are modeled mathematically as a system of non-linear differential equations, that are solved under long-wavelength approximation and low Reynolds number conditions using the perturbation method. The results for nanofluid and temperature described the behavior of the pumping characteristics during their interaction with (the vertical position, thermal radiation, the shape of the nanoparticle, and the magnetic field) analytically and explained graphically. Also, the combined effects of thermal radiation parameters and some physical parameters on pressure rise, pressure gradient, velocity, and heat distribution are pointed out. Qualitatively, a reverse velocity appears with combined high radiation and Grashof number or combined high radiation and low volume flow rate. At high radiation, the spherical nanoparticle shape has the greatest effect on heat distribution.

• 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.

• The Korean Journal of Food And Nutrition
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• v.28 no.3
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• pp.486-492
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• 2015

This study was conducted to provide fundamental data on the awareness of radiation, specifically the differences between general awareness, psychological state and harmful effects. Data was collected from 334 University students in the Chungbuk region through a self-administered questionnaire. According to the results of the reliability and factor analysis, the awareness of radiation was 2.80, with a Cronbach alpha coefficient of 0.815 and KMO of 0.798. Factor analysis extracted three components of the awareness of radiation, which we named general awareness (factor 1), psychological state (factor 2), and harmful effect (factor 3). There were significant differences in the general awareness of natural radiation and radiation-containing foods (p<0.05), whereas no significant differences were found in the general awareness of radiation food supply (p>0.05). Also, the psychological state showed a significant difference in exposure inspection, future exposure, and radiation-containing food (p<0.05), whereas no significant differences were found in the refusal of radiation inspection (p>0.05). The harmful effects showed a significant difference in the rejection of radiation (p<0.05), but no significant differences in the cancer and genetic effects, diseases and physical harmfulness (p>0.05). A significant positive result (p<0.05) was found for the psychological state according to the harmful effects of radiation. Based on this study, detailed and continuous education must be accomplished by increasing the awareness of radiation and the acceptance level, conveying a proper understanding of radiation and assisting subjects with receiving the information they desire through various educational mediums.

• Journal of Photoscience
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• v.1 no.2
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• pp.135-141
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• 1994

Elevated near-UV radiation, containing a large amount of UV-B and a small amount of UV-C, inhibited the development of leaves and tillers, the increase in biomass production, the elongation of plant height, the photosynthetic rate and the chlorophyll content in rice plants in a phytotron. Elevated UV-B radiation filtered through cellulose diacetate film or UV-31 cut filter (transmission down to 290 nm) similarly suppressed each growth component above. Near-UV radiation-caused injuries were alleviated either by elevated CO$_2$ atmosphere or by exposure to high irradiance-visible radiation. On the basis of these findings, we examined cultivar differences in the resistance to UV radiation-caused injuries among 198 rice cultivars belonging to 5 Asian rice ecotypes ( aus, aman, boro, bulu and tjeleh) from the Bengal region and Indonesia and to Japanese lowland and upland rice groups. It was shown that .various cultivars having different sensitivities to the effects of near-UV radiation were involved in the same ecotype and the same group, and that the Japanese lowland rice group and the boro ecotype were more resistant. Among Japanese lowland rice cultivars, Sasanishiki (one of the leading varieties in Japan) exhibited more resistance to near-UV radiation, while Norin 1 showed less resistance, although these two cultivars are closely related. It was thus indicated that the resistance to the inhibitory effects of near-UV radiation of rice cultivars is not simply due to the difference in the geographical situation where rice cultivars are cultivated. From the genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice using F$_2$ plants generated by reciprocally crossing Sasanishiki and Norin 1 and F$_3$ lines generated by self-fertilizing F$_2$ plants, it was evident that the resistance to the inhibitory effects of elevated near-UV radiation in these rice plants was controlled by recessive polygenes.

• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.568-574
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• 2024

The development of radiation-tolerant radio-frequency (RF) systems can be a solution for applications in extreme radiation environments, such as nuclear power plant monitoring and space exploration. Among the crucial components within an RF system, the low noise amplifier (LNA) stands out due to its vulnerability to TID effects, mainly relying on transistors as its main devices. In this study, the TID effects in the LNA using standard 0.18 ㎛ complementary metal oxide semiconductors (CMOS) technology are estimated and analyzed. The results show that the LNA can withstand absorbed radiation up to 100 kGy. The S₂₁, S₁₁, noise figure (NF), stability (K), and linearity of the third input intercept point (IIP3) slightly shifted from the initial values of 0.8312 dB, 0.793 dB, 0.00381 dB, 1.34406, and 2.36066 dBm, respectively which are still comparable to the typical performances. Moreover, the standard 0.18 ㎛ technology has demonstrated its radiation tolerance, as it exhibits negligible performance degradation in the conventional LNA even when exposed to radiation levels up to 100 kGy. In this context, simulation approach offers a means to predict the TID effects and estimate the radiation exposure limit for electronic devices, particularly when transistors are used as the primary RF components.

• Physical Therapy Korea
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• v.9 no.3
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• pp.1-9
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• 2002

The purpose of this study was to compare the experimental pain threshold when used in luminous lamp radiation and nonluminous lamp radiation with healthy person. Thirty normal subjects were randomly assigned two groups: a luminous lamp radiation group, and a nonluminous lamp radiation group. The infrared lamps were applied on L3 for thirty minutes. Each group was measured for experimental pain threshold and local temperature before, 15 and 30 minute radiation. For statistical differences in change of the experimental pain threshold and local temperature due to differences in lamp ray was compared using the independent t-test. And, General linear model for profile plots test was used. The results were as: 1. Local temperature was significantly increased in the nonluminous lamp group (p<.01). 2. Experimental pain thershold was significantly increased in the luminous lamp group (p<.05),(p<.01). This study indicate that luminous lamp radiation was more effects of increase experimental pain thershold than nonluminous lamp radiation. Further study is needed to compare the effects of after period radiation.