• Journal of radiological science and technology
• /
• v.15 no.1
• /
• pp.123-130
• /
• 1992

This study was prepared to observe the change of enzyme activities in kidney treated with red ginseng extract in the gamma ray irradiated mice. Determine the activity of SOD, peroxidase, catalase in the kidney a period of 1 day, 2 day, 3 day, 4 day, 5 day after a saline injection or injection of red ginseng extract or gamma ray irradiatied group into four classify. The activity SOD and catalase showed a tendency to increase and recovery at the early state but pay no regard. Wherease, the activity of peroxide restored and increased pay regard. A physiological saline injection group after gamma ray irradiation showed a tendency to diminish after remakable increase of activity of SOD, peroxidase and catalase than control group. Injection group of red ginseng extract after gamma ray irradiation observed rapid recovery on activity of SOD, peroxidase, catalase than a saline injection group. Experimental result suggested that injection of red ginseng extract after irradiation have the recovery effect on the changed of activity of SOD, peroxidase and catalase against radiation injury.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.10
• /
• pp.1980-1986
• /
• 2016

In this study, we studied the gamma-radiation effect of fiber Bragg gratings (FBGs) on the high temperature annealing condition after grating inscription using a KrF UV laser (248 nm). The FBGs were fabricated in a different annealing temperature using the same commercial Ge-doped silica core fiber (SMF-28e) and exposed to gamma-radiation up to a dose of 31 kGy at the dose rate of 115 Gy/min. The high temperature annealing procedure for grating stabilization was applied to change the radiation sensitivity of the FBGs. According to the experimental data and analysis results, the gratings that were stabilized at different temperatures at 100, 150 and $200^{\circ}C$ have clearly shown that exposure to higher temperatures increases their radiation sensitivity. The radiation-induced Bragg wavelength shift (BWS) was shown a difference of up to about a factor of two depending on the annealing temperature conditions of the gratings.

• Journal of the Korean Society of Radiology
• /
• v.17 no.2
• /
• pp.201-206
• /
• 2023

In order to improve the spatial resolution of the gamma camera, the size of the hole in the collimator must be reduced, so the sensitivity is reduced. In order to improve the sensitivity, the size of the hole must be increased, and thus the spatial resolution is reduced. In other words, spatial resolution and sensitivity show opposite characteristics. In this study, a gamma camera was designed to improve both spatial resolution and sensitivity. In order to obtain higher sensitivity in gamma cameras with the same spatial resolution, the structure of the scintillator was designed differently from the existing system. A scintillation pixel was used, and a partition wall was placed between the scintillation pixels to prevent incident gamma rays from being transmitted to other scintillation pixels to interact. Geant4 Application for Tomographic Emission (GATE) simulation was performed to evaluate the performance of the designed gamma camera. When the same sensitivity as the block-type scintillator was obtained, the spatial resolution increased by 16.5%, and when the same spatial resolution was obtained, the sensitivity increased by 61.5%. It is considered that the use of the gamma camera designed in this study can improve the sensitivity compared to the existing system while securing excellent spatial resolution.

• 대한방사선방어학회:학술대회논문집
• /
• 2009.04a
• /
• pp.236-237
• /
• 2009

• 대한방사선방어학회:학술대회논문집
• /
• 2011.04a
• /
• pp.174-175
• /
• 2011

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.12
• /
• pp.2310-2316
• /
• 2016

We studied the effect of $Co^{60}$ gamma-radiation on the fiber Bragg gratings (FBGs) by irradiation time of UV Krypton fluoride (KrF) excimer laser among grating processing parameters. The FBGs were fabricated in a different UV laser irradiation time at 30, 60, 90, and 120 seconds using the same commercial Ge-doped silica core fiber (SMF-28e). It was exposed to gamma-radiation up to a high dose of 34.3 kGy at the dose rate of 106 Gy/min, and then it was analyzed radiation effects by measuring the radiation-induced change in the temperature sensitivity coefficient and Bragg wavelength shift. According to the experimental results, We confirmed that the UV laser irradiation period for grating inscription has a highly effect on the radiation sensitivity of the FBGs. The radiation-induced Bragg wavelength shift by the change of laser irradiation conditions showed a difference more than about 50 %.

• Korean Journal of Food Science and Technology
• /
• v.47 no.3
• /
• pp.388-393
• /
• 2015

This study aimed to investigate the therapeutic effect of rutin against whole-body ${\gamma}$-irradiation in BALB/c mice. BALB/c mice were randomly divided into four groups and exposed to 6 Gy ${\gamma}$-irradiation. One hour later, mice were orally administered rutin (50 and 100 mg/kg) for seven consecutive days. ${\gamma}$-Irradiation (6 Gy) resulted in cellular damage as manifested by elevated levels of plasma hepatic marker enzymes and lipid peroxidation in liver tissue, accompanied with decreased spleen and thymus indices, and white blood cell count. In addition, ${\gamma}$-irradiation significantly decreased the levels of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase and catalase. Rutin treatment significantly protected against ${\gamma}$-irradiation-induced cellular damage, which was evident by the improvement in the status of most of the investigated parameters. Therefore, rutin has beneficial effects against radiation-induced damage.

• The Korean Journal of Mycology
• /
• v.40 no.2
• /
• pp.93-97
• /
• 2012

Gamma ray irradiation mutagenesis was employed to get variants of Pleurotus eryngii with functionally enhanced and improved characteristics. Protoplasts released from P. eryngii were treated with gamma ray radiation under 0.25-1.25 KGy. Protoplast sample that showed fatality rate of 80% at the 0.25 KGy was spreaded on YPMGA (yeast, peptone, malt-extract, glucose, agar) and 500 mycelial colonies were randomly selected from the medium. Of them, 100 mutant strains with mycelial morphology and growth rate that differ to control strain were observed on PDA. The cellulase and laccase activity of 67 gamma ray-irradiated P. eryngii isolates with morphological variation were investigated. Among these, 5 isolates were higher cellulase. In addition, the genetic variation of the mutant strains was analyzed by PCR fingerprinting.

• Korean Journal of Environmental Biology
• /
• v.22 no.3
• /
• pp.472-477
• /
• 2004

To study the radiation related gene expression in mutants of Bacillus lentimorbus WJ5 induced by gamm radiation, the simultaneous gene expression was analyzed by DNA micro array. We constructed DNA chips including two thousand randomly digested genome spots of B. lentimorbus WJ5 and compared its quantitative aspect with seven mutants induced by gamma radiation $(^{60}/Co)$. From the cluster analysis of gene expression pattern, totally 408 genes were expressed and 27 genes were significantly upregulated by the gamma radiation in all mutants. Especially, genes involved in repair (mutL, mutM), energy metabolism (acsA, sdhB, pgk, yhjB, citB), protease (npr), and reduction response to oxidative stress (HMM) were simultaneously upregulated. It seems that the induction of the direct and/or indirect repair related genes in mutants induced by gamma radiation could be remarkably different from the adaptive responses against acute exposure to radiation.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.8
• /
• pp.2023-2028
• /
• 2014

In this study, we studied the effect of $Co^{60}$ gamma-radiation on the FBGs written in photo-sensitive and commercial Ge-doped single-mode optical fibers. The FBGs were exposed to gamma-radiation up to a dose of 17.8 kGy at the dose rate of 300 Gy/min. According to the experimental data and analysis results, the lowest Bragg wavelength shift (18 pm) was obtained by a grating written in photosensitive fiber without $H_2$-loading. Also, we confirmed that the H2 loading process has considerably more influence on the Bragg wavelength shift change under gamma radiation than $GeO_2$ contents in the fiber core.