• Imaging Science in Dentistry
• /
• v.35 no.3
• /
• pp.133-139
• /
• 2005

Purpose To observe the histopathological changes in the periodontal tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. Materials and Methods : The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups: control, diabetes, irradiation, and diabetes- irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control and irradiation groups were injected with citrate buffer only After 5days, the head and neck region of the rats in irradiation and diabetes-irradiation groups were irradiated with a single absorbed dose of 10Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. Results In the diabetes group, osteoclastic activity was observed in the alveolar bone and the root throughout the period of experiment. Also, osteoblastic and fibroblastic activities were markedly decreased. In the irradiation group, the osteoclasts were observed in the alveolar bone and the dilated capillaries were increased in the early experimental phases. However, vigorous osteoblastic activity was noted in the late experimental phases. In the diabetes-irradiation group, osteoblastic activity in the alveolar bone and the root was observed in the early experimental phases. However, there were no resorption and osteoblastic activity in the alveolar bone and the root in the late experimental phases, and obvious atrophic change of fibrous tissues was noted. Conclusion : This experiment suggests that osteoblastic activity was caused by irradiation in the late experimental phases, but atrophic change of the periodontal ligament tissues was induced after irradiation in diabetic state.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.4
• /
• pp.334-338
• /
• 2003

The objective of this study was to demonstrate whether or not the deleterious effects of accelerated aging on seed vigour and viability are alleviated by interaction with gamma irradiation. Seeds of soybean (Glycine max L.) were artificially aged and subsequently irradiated with 4 and 8 Gy of gamma irradiation. Germination rate was negatively affected by accelerated aging and positively by gamma irradiation, with a positive interaction of a 3day-seed aging treatment occurring with 4 Gy, possibly suggesting that 4 Gy of gamma irradiation partially offset the adverse effects of seed aging on germination. However, 5-day aged seeds did not gain any benefits from the gamma irradiation. Electrolyte leakage from the seeds increased with the duration in days aged. Irradiation, however, did not impose any effects on the leakage. Respiration rate of the seed with hypocotyl and primary root was significantly low for the aged seeds, but not for the seeds with both irradiation and aging treatments. Accelerated aging decreased the dry weight of the hypocotyl and primary root of the seeds without any measurable effects of irradiation. $\alpha$-Amylase activity decreased with seed aging and positively responded to gamma irradiation. The data is discussed with regard to the possible roles of gamma irradiation for improving the seed vigour and viability of aged seeds.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.6
• /
• pp.824-831
• /
• 2011

This study was to investigate 90-day repeated-dose toxicities of 50 kGy irradiated methanol extract powder of red ginseng in ICR mice. The test materials (methanol extract powder of red ginseng with or without 50 kGy irradiation) were administered by gavage to male and female ICR mice at dose levels of 0, 125, 250 and 500 mg/kg/day for 90 days. In the results, no abnormality was observed in mortality, clinical findings, body weight changes, food consumptions, opthalmoscopic findings, necropsy findings and histopathological findings. Although the minor changes in blood and biochemical parameters were observed, they were not dose dependent and not affected by gamma irradiation. In conclusion, 90-day repeated oral dose of the methanol extract powder of red ginseng and 50 kGy irradiated methanol extract powder of red ginseng to ICR mice did not cause apparent toxicological change at the dose of 125, 250 and 500 mg/kg body weight.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.51 no.6
• /
• pp.71-77
• /
• 2014

In this paper, we investigated the effects of high-energy electron beam irradiation (HEEBI) on the optical transmittance of InGaZnO (IGZO) films grown on transparent Corning glass substrates, with a radio frequency magnetron sputtering technique. The IGZO thin films deposited at low temperature were treated with HEEBI in air at room temperature (RT) with an electron beam energy of 0.8 MeV and doses of $1{\times}10^{14}-1{\times}10^{16}electrons/cm^2$. The optical transmittance of the IGZO films was measured using an ultraviolet visible near-infrared spectrophotometer (UVVIS). The detailed estimation process for separating the transmittance of HEEBI-treated IGZO films from the total transmittance of IGZO films on transparent substrates treated with HEEBI is given in this paper. Based on the experimental results, we concluded that HEEBI with an appropriate dose of $10^{14}electrons/cm^2$ causes a maximum increase in the transparency of IGZO thin films. We also concluded that HEEBI treatment with an appropriate dose shifted the optical band gap ($E_g$) toward the lower energy region from 3.38 to 3.31 eV. This $E_g$ shift suggested that HEEBI in air at RT with an appropriate dose acts like a thermal annealing treatment in vacuum at high temperature.

• Toxicological Research
• /
• v.13 no.1_2
• /
• pp.55-60
• /
• 1997

Gamma irradiation was applied to Angelicae gigantis radix and Aloe to improve their hygienic quality. The effective dose of irradiation was 7 kGy in Angelicae gigantis radlx and 5 kGy in Aloe for the sterilization of all contaminated microorganisms tested. After 8 months of storage at room temperature, no growth of microorganisms was observed in the irradiated products. The safety of these products were evaluated by Salmonella typhimurium reversion assay and in vivo micronucleus assay using mouse bone marrow cells. They were negative in the bacterial reversion assay with S. typhimurium TA 98, TA100, TA1535 and TA1537. In the in vivo mouse micronucleus assay, they did not show any clastogenic effect at all doses tested. These results indicate that the gamma irradiation of Angelicae gigantis radix at 12 kGy and of Aloe at 10 kGy have no genotoxic effects under these experimental conditions.

• Food Science and Preservation
• /
• v.6 no.1
• /
• pp.16-22
• /
• 1999

Microbial populations (total bacteria, lactic acid bacteria and coliforms), TBA, VBN and POV were investigated for evaluating the shelf life of pork loins gamma-irradiated at doses of 1, 3, 5 and 10 kGy with air-contained and vacuum-packaged methods. The initial microbial populations decreased with gamma irradiation depending upon the dose and microorganisms in the vacuum-packaged samples were inhibited more than those in the air-contained samples. POV, TBA and VBN values were higher in the air-contained samples than in the vacuum-packaged samples. In conclusion, the combination of gamma-irradiation and vacuum-packaging could extend the shelf life of chilled pork loin.

• Journal of the Korean Magnetic Resonance Society
• /
• v.12 no.2
• /
• pp.74-80
• /
• 2008

The local structure of defects in undoped, Si-doped, and neutron irradiated free standing GaN bulk crystals, grown by hydride vapor phase epitaxy, has been investigated by employing electron magnetic resonance(EMR), Raman scattering and cathodoluminescence. The GaN samples were irradiated to a dose of $2{\times}10^{17}$ neutrons in an atomic reactor at Korea Atomic Energy Research Institute. There was no appreciable change in the Raman spectra for undoped GaN samples before and after neutron irradiation. However, a forbidden transition, $A_1$(TO) mode, appeared for a neutron irradiated Si-doped GaN crystal. Cathodoluminescence spectrum for the neutron irradiated Si-doped GaN crystal became much broader or was much more broadened than that for the unirradiated one. The observed EMR center with the g value of 1.952 in a neutron irradiated Si-doped GaN may be assigned to a Si-related complex donor.

• Journal of Applied Tourism Food and Beverage Management and Research
• /
• v.13 no.2
• /
• pp.1-10
• /
• 2002

This research was conducted to investigate changes in quality characteristics of gamma-irradiated chickens during storage at different temperature and periods. The proximate composition of Chicken was not significantly changed by irradiation dose and storage period. No significant difference in the components of fatty acids we were observed by gamma irradiation. In general, the amount of released free amino acid was increased during storage and was not significantly changed by gamma irradiation.

• Fibers and Polymers
• /
• v.5 no.3
• /
• pp.225-229
• /
• 2004

The effect of UV and $^60{Co}$ gamma radiations on the physical and mechanical properties of nylon 6 mono-filaments with different draw ratios has been studied. Specimens were exposed to either up to 25 Mrad of gamma or up to 168 hrs of intense UV irradiation. The results show that nylon mono-filaments exposed to gamma rays, with much higher quantum energy than UV, undergo a larger extent of molecular chain scission. Higher irradiation dose also results in the production of insoluble, macroscopic three-dimensional cross-linked network structure. The amorphous regions with a lower density of cohesive energy (lower molecular orientation) show a higher extent of cross linking reaction whereas amorphous regions with a higher density of cohesive energy (higher orientation) show higher extent of chain scission reaction, irrespective of UV ray or gamma ray irradiation.

• Preventive Nutrition and Food Science
• /
• v.11 no.1
• /
• pp.73-77
• /
• 2006

Ground pork was irradiated with an electron beam (e-beam) at a dose of 0, 1.5, 3, 5 and 10 kGy and the changes in various functional and other associated properties of salt-soluble proteins extracted from the pork were evaluated. Irradiation did not affect turbidity and the disulfide content of pork salt-soluble protein, but the content of sulfhydryls and the hydrophobocity of salt-soluble protein increased. This indicates that protein degradation occurred when the pork was e-beam irradiated and that the sulfhydryls and hydrophobic moieties buried inside the proteins were exposed to the outside environment. However, these degraded protein molecules did not form large protein aggregates through disulfide bridges. The emulsifying capacity of the pork increased with irradiation, which could be the result from increased hydrophobicity of pork salt-soluble protein. Water holding capacity of pork was not affected bye-beam irradiation.