• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.747-754
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• 2000

DNA damages in post-mortem bovine muscle samples caused by gamma irradiation at doses of 1 to 10 kGy were determined by Comet assay. When the cell extract was prepared in a physical method and followed by neutral lysis and neutral electrophoresis, the optimal comet images could be obtained. DNA damages were evaluated from the mean tail length, the distributions of comet images in 4 groups divided by tail length and the relative damage index (RDI) values calculated from the distribution pattern. The mean tail length and RDI value were increased by increasing the irradiation dose, and the RDI value was found to be useful as an index for discriminating of irradiation and measuring the irradiated dose. Blind tests using Korean domestic (Hanwoo) and imported beef samples showed a higher RDI value for the latter. However, the value was lower than those of irradiated samples indicating that the cause of DNA damages in the imported beef samples might be not irradiation but low-temperature treatments. It was concluded from the results of this study that the irradiated beef and its irradiated dose could be detected and predicted by Comet assay.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.659-667
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• 2017

The present study was designed to evaluate the antioxidant activity and radioprotective effects of Naringin and Naringenin in ${\gamma}$-irradiated mice. The antioxidant activity of Naringin and Naringenin was evaluated by 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) assays. Healthy female BALB/c mice were administered Naringin and Naringenin orally ($90{\mu}M/dose$ and $180{\mu}M/dose$) for 7 consecutive days prior to ${\gamma}$-irradiation (6 Gy). Naringenin displayed a much higher antioxidant activity in ABTS and FRAP than naringin. ${\gamma}$-irradiation resulted in cellular damage with decreased spleen and thymus indices and white blood cells (WBC) count. Additionally, ${\gamma}$-irradiation significantly increased lipid peroxidation and decreased the levels of antioxidant enzymes and glutathione (GSH) in the liver tissue. Strikingly, prior administration of Naringenin resulted in considerable prevention of these symptoms. Protection against ${\gamma}$-irradiation-induced cellular damage by Naringenin is likely due to its higher its antioxidant activity. Together, these results confirm that Naringenin is a potent antioxidant and radioprotector.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.623-630
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• 2016

Liver tissue damage by a radiation exposure caused a jaundice and ascitic fluid e form harden atrophy. The reason for this lies in morphological damage of a liver cells. This study tried that observe damage mechanism of the cell organelles. It was especially observed mitochondria, endoplasmic reticulum and nuclear membrane associated with energy metabolizable. also, This study had with a radio-protector development research at the same time. Radio-protector was used to alliin that has an blood flow increase. Cell observation make used of transmission electron microscope(TEM). The result of an experiment, 7Gy of whole body irradiation was caused an inflammation in cell organelles and hypertrophy of the nucleus membrane. After 20 days, The hepatocyte has been observed in a damaged membrane on peroxisome, mitochondria and vacuole of the cell organelles. After 30 days, The hepatocyte has been observed in disconnected ribosomes on a rough endoplasmic reticulum. There was looked a giant lipoblast. There was clearly normal observed a mitochondria and nucleus membrane in the hepatocyte after alliin injection. aslo, It was no damaged the nucleus membrane. therefore, It was identified portion a radio-protector effect from alliin.

• Journal of Radiation Protection and Research
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• v.31 no.2
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• pp.65-68
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• 2006

In this study, the extent of plasmid DNA damage was observed according to concentration of BSH(Boron Sulfhydryl Hydride) and irradiation doses of neutron and ${\gamma}$-ray. The plasmid used was both pBR 322 (2870 bp) and ${\Phi}X174$ RF(5386 bp) DNA. Plasmid DNA damage by irradiation in the presence of BSH was analyzed by agarose gel electrophoresis. In the neutron experiment, DNA damage of both plasmid DNAs was increased according to increasing the concentration of BSH and neutron doses. But in the ${\gamma}$-ray experiment, there appeared no dose dependency as compared to the neutron experiment. The extent of the plasmid DNA damage in the presence of BSH was somewhat different according to irradiation by neutron or ${\gamma}$-ray.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.79-95
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• 1997

Purpose : Phospholipase C(PLC) isozymes play significant roles in signal transduction mechanism. $PLC-\gamma$ 1 is one of the key regulatory enzymes in signal transduction for cellular proliferation and differentiation. Ras oncoprotein, EGFR, and PKC are also known to be involved in cell growth. The exact mechanisms of these signal transduction following irradiation, however, were not clearly documented Thus, this study was Planned to determine the biological significance of PLC, ras oncoprotein, EGFR, and PKC in damage and regeneration of rat intestinal mucosa following irradiation. Material and Method : Sixty Sprague-Dawley rats were irradiated to entire body with a single dose of 8Gy. The rats were divided into S groups according to the sacrifice days after irradiation. The expression of PLC, ras oncoprotein, EGFR and PKC in each group were examined by the immunoblotting and immunohistochemistry. The histopathologic findings were observed using H&I stain, and the mitoses for the evidence of regeneration were counted using the light microscopy & PCNA kit. The Phosphoinositide(PI) hydrolyzing activity assay was also done for the indirect evaluation of $PLC-\gamma$ 1 activity. Results: In the immunohistochemistry , the expression of $PLC-{\beta}$ was negative for all grøups. The expression of $PLC-{\gamma}1$ was highest in the group III followed by group II in the proliferative zone of mucosa. The expression of $PKC-{\delta}1$ was strongly positive in group 1 followed by group II in the damaged surface epithelium. The above findings were also confirttled in the immunoblotting study. In the immunoblotting study, the expressions of $PLC-{\beta}$, $PLC-{\gamma}1$, and $PKC-{\delta}1$ were the same as the results of immunohis-tochemistry. The expression of ras oncoprctein was weakly positive in groups II, III and IV. The of EGFR was the highest in the group II, III, follwed by group IV and the expression of PKC was weakly positive in the group II and III. Conclusion: $PLC-{\gamma}1$ mediated signal transduction including ras oncoprotein, EGFR, and PKC play a significant role in mucosal regeneration after irradiation. $PLC-{\delta}1$ mediated signal transduction might have an important role in mucosal damage after irradiation. Further studies will be necessary to confirm the signal transduction mediating the $PKC-{\delta}1$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.3079-3084
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• 2014

When an integrated circuit device is burned out under high-intense radiation and device-level simulation that usually requires manufacturer's proprietary information is not available, experimental conformation of a failure mechanism is often the only choice. To distinguish Latchup from other causes experimentally, a new combination of multiple techniques have been developed and demonstrated. Power supply circumvention, hot-spot monitoring using an infrared camera, and supply current monitoring techniques were implemented for the conformation of the Latchup.

• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.243-248
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• 2023

This study aims to analyze the secondary carcinogenesis rate caused by exposure of organs at risk of damage using a glass dosimeter during radiosurgery in vestibular schwannoma disease. Using a pediatric phantom of human tissue equivalent material, the volume of the tumor was set to a total of three volumes: 0.506 cm³, 1.008 cm³, and 2.032 cm³, and a radiosurgery plan was established with an average dose of 18.4 ± 3.4 Gy. After mounting the human body phantom on the table of surgical equipment, glass dosimeters were placed on the right eye, left eye, thyroid gland, thymus, right lung, and left lung to measure the exposure dose, respectively. In this study, the incidence of secondary cancer due to exposure to damaged organs during gamma knife radiosurgery in vestibular schwannoma disease with the largest tumor volume of 2.032 cm³ was measured with a glass dosimeter. This study studies the risk of secondary radiation exposure dose that can occur during stereotactic radiosurgery, and it is considered that it will be used as basic data in the field of radiation damage related to the stochastic effect of radiation in the future.

• Journal of Sensor Science and Technology
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• v.9 no.5
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• pp.350-356
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• 2000

The optimum composition ratios of primary solute(p-terphenyl) and secondary solute(popop) have been investigated in order to fabricate plastic scintillator with higher light output and less radiation damage. The radiation damage induced by $^{60}Co$ $\gamma$-irradiation depends on mainly the concentration of secondary solute. The spectral range of the luminescence was $400{\sim}450\;nm$, its peak emission appeared at 415 nm. The transmittance and the light output were not changed by radiation damage up to $1{\times}10^4\;Gy$ irradiation with $^{60}Co$ $\gamma$-rays.

• Journal of radiological science and technology
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• v.27 no.3
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• pp.13-18
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• 2004

In most patients with facial palsy after temporal bone injury, temporal bone High Resolution CT revealed direct or indirect facial nerve canal involvement, and in complete palsy severe degeneration groups, there were direct findings in most cases. Author believe that meticulous analysis and symptom correlation of the fracture patterns seen in facial canal injury in patients with traumatic facial nerve palsy is helpful for treatment planning and prognosis.

• Radiation Oncology Journal
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• v.22 no.1
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• pp.40-54
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• 2004

Purpose : Captopril (angiotension converting enzyme inhibitor) is known to have a radioproptective effect in the lungs, intestines and skin, but its effect in the heart is unclear. To investigate the radioprotectlve efiect and mechanism of captopril on the heart, the histopathological changes and immunohistochemical stains were compared with radiation alone, and radiation combined with captopril, in the rats. Materials and Methods : The histopathological changes and immunohistochemical stains ($TNF{\alpha}$, $TGF{\beta}1$, PDGF and FGF2) were examined in the radiation alone and the combined captopril and radiation groups, 2 and 8 weeks after irradiation. Each group consisted of 8 to 10 rats (Sprague-Dawley). Irradiation (12.5 Gy) was given to the left hemithorax in a single fraction. Captopril (50 mg/Kg/d) mixed with water, was given orally and continuously from the first week prior to, up to the 8th week of the experiment. Results : In the radiation alone group, the ventricle at 2 weeks after irradiation showed prominent edema (p=0.082) and fibrin deposit (p=0.018) compared to the control group. At 8 weeks, the edema was decreased and fibrosis increased compared to those at 2 weeks. The histopathological changes of the combined group were similar to those of the control group, due to the reduced radiation toxicity at 2 and 8 weeks. The endocardial fibrin deposit (p=0.047) in the atrium, and the interstitial fibrin deposit (p=0.019) and edema (p=0.042) of the ventricle were reduced significantly in the combined group compared to those in the radiation alone group at 2 weeks. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$, PDGF and FGF-2 in the radiation alone group were more increased than in the control group, especially in the pericardium and endocardium of the atrium at 2 weeks. At 8 weeks, the pericardial $TNF-{\alpha}$ and $TGF-{\beta}1$ in the radiation alone group continuously increased. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$ and PDGF were decreased in the combined group at 2 weeks. At 8 weeks, the expressions of $TNF-{\alpha}$ in the atrial and ventricular pericardia were markedly reduced (p=0.049, p=0.009). Conclusion : This study revealed that the early heart damage induced by radiation can be reduced by the addition of captopril in a rat model. The expressions of $TNF-{\alpha}$, $TGF-{\beta}1$ and PDGF were further decreased in the combined compared to the radiation alone group at both 2 and 8 weeks. From these results, it may be concluded that these cytokines probably play roles in the radioprotective mechanism of captopril from the radiation-induced heart toxicity, similarly to in other organs.