• Progress in Medical Physics
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• v.5 no.2
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• pp.13-20
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• 1994

The thermoluminescence(TL) glow curves and the optical absorption of $Al_2O_3$ irradiated with ${\gamma}$-ray, electron, and $Li^{+}$ ion followed by electron irradiation have been investigated to determine the relation of TL peak to its defect type. The TL glow curve of $Al_2O_3$ irradiated with ${\gamma}$-ray shows TL peaks at 380 K, 415 K, and 475 K. The UV photobleached TL glow curve of $Al_2O_3$ irradiated with ${\gamma}$-ray shows that the 380 K and 475 K TL peaks completely disappear while the 415 K TL peak still exists. The electron beam induced TL glow curve of $Al_2O_3$ after $Li^{+}$ ion implantation shows that the TL peak at 440 K is enhanced by a factor of 2 over the TL intensity of unimplanted $Al_2O_3$ while the TL peak at 380 K evidently disappears The implanted $Li^{+}$ ions are assumed to form singly charged interstitial cations and then recombine with electron trapped in F centers to produce F+ centers. The 380 K and 475 K TL peaks are proposed to be associated with F center, while the 415 K and 440 K TL peak are connected with F$^{+}$ center.

• Food Science and Preservation
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• v.21 no.3
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• pp.315-320
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• 2014

This study evaluated the effects of a gamma ray (GR), electron beam (EB), and X-ray (XR) to improve the safety of black pepper powder. The black pepper powder was irradiated by GR, EB, and XR at 2, 4, 6, 8, and 10 kGy. The results of the total bacterial populations in the black pepper power sample showed a similar effect on microbial decontamination for radiation sources. Radiation sensitivity ($D_{10}$ value) on the initial bacteria loads in the sample was 2.24 kGy in GR, 2.37 kGy in EB, and 2.75 kGy in XR. In addition, there were no differences among the radiation sources. The color values, such as L (lightness), a (redness), and b (yellowness), were not changed significantly. The sensory characteristics of GR, EB, and XR irradiated black pepper powder were decreased when the radiation dose increased, but there was no significant changes among the radiation sources. The results can be applied to investigate the effects of radiation sources on the microbiological and sensory characteristics of black pepper powder.

• Korean Journal of Food Science and Technology
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• v.4 no.2
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• pp.100-105
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• 1972

This experiment was conducted to investigate the combined effects of radiation and antiseptics on the keeping qualities of pork sausage, which was treated with potassium sorbate and AF-2(2-(-2-furyl)-3-(5-nitro-2-furyl)-acrylamide), and then followed by gamma radiation of 0.25, 0.5, and 0.75 Mrad. Amounts of treated antiseptics were a quarter, half, and full levels of their maximum permissible concentration. Irradiated and unirradiated sausages were stored for 50 days at $5^{\circ}C\;and\;25^{\circ}C$, and their changes in rancidity, volatile basic nitrogen, bacterial counts, pH, and sensory analysis were examined during the storage period. The results obtained are as follows: 1) Preservative effects of antiseptics were manifested at cold storage; antiseptics treatment of a quarter-level and unirradiation following low-temperature storage showed the same good keeping qualities as the combined treatment of full-level antiseptics and radiation of 0.25 Mrad following high-temperature storage. 2) There did not appear to recognize irradiation-odor, while color and odor were deteriorated intensively by storage temperature. Sausage irradiated with 0.75 Mrad has shown slightly noticeable off-odor at the end of storage at $25^{\circ}C$. 3) The most suitable radiation dose was considered to be 0.5 Mrad, which could extend the storage life about $2{\sim}3$ times longer than untreated.

• Journal of Radiation Protection and Research
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• v.23 no.1
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• pp.49-57
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• 1998

Domestic intercomparison study of the neutron personnel dosemeters was performed for the first time in Korea. Thirteen types of neutron dosemeters from twelve institutions took part in this intercomparison study and the $D_2O$ moderated Cf-252 source of KAERI was used for irradiation. Eight of the fifteen dosemeters submitted by each participant were divided into two groups and each group was irradiated with different doses of the simulated mixed fields of neutron and gamma. The participants assessed their dosemeter reading in terms of the personal dose equivalent, Hp(10), for both neutron and gamma dose. The ratio of the reported dose equivalent to the delivered dose equivalent for comparison between participants ranged from 0.55 to 1.34 for neutron, from 0.54 to 1.32 for gamma and from 0.75 to 1.20 for total dose. This intercomparison results show that all dosemeter processors, especially for neutron category, are able to pass the personnel dosemeter performance test which shall be enforced according to the ordinance of the MOST, No. 96-6.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.37-43
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• 2013

We examined the forage quality to provide the basic information for the utilization of blackberry by-products (leaf and stem) among thirty-five mutant lines derived from gamma-ray. The leaves had higher crude protein (CP) contents than stems. In addition, the leaves showed broad ranges of variation in crude fat, crude fiber and crude ash. The overall forage quality of the stems were similar to those of the original variety. The mean of neutral detergent fiber (NDF) content of leaves and stems in mutant lines were 25.88% and 58.98%, respectively. Also, the mean of acid detergent fiber (ADF) content of leaves and stems in mutant lines were 15.43% and 49.27%, respectively. Forage quality grades of all blackberry leaf were special quality class. However, the blackberry stem ranked $1^{st}$ to $5^{th}$ in quality class. The stem diameter was negatively ($P{\leq}0.05$) correlated with the moisture and crude protein. Also, the fruit length was highly negatively ($P{\leq}0.01$) correlated with the RFV (relative feed value) in blackberry leaf. The one hundred fruit weight was highly negatively ($P{\leq}0.01$) correlated with the crude ash. Based on these results, the by-products of blackberry could provide high quality forage for feeding of live stock.

• Clean Technology
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• v.25 no.2
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• pp.123-128
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• 2019

$Bi_2MoO_6$ catalysts were successfully synthesized using ethylene glycol monomethyl ether (EGME), glycerol (GL), ethylene glycol (EG), and water as solvents by a conventional hydrothermal method. The synthesized catalysts were characterized by XRD, DRS, BET, SEM, and PL, and we also investigated the photocatalytic activity of these materials for the decomposition of Rhodamin B under visible light irradiation. The XRD results revealed the successful synthesis of 12-18 nm, well-crystallized ${\gamma}-Bi_2MoO_6$ crystals with an Aurivillius structure regardless of solvent. In addition, the $Bi_2MoO_6$ catalysts prepared below $140^{\circ}C$ showed an amorphous phase; however, those prepared above $160^{\circ}C$ showed well-crystallized ${\gamma}-Bi_2MoO_6$ crystals. All the catalysts have a similar absorption spectrum from the ultraviolet region up to the visible region less than 470 nm. This result suggests that all the $Bi_2MoO_6$ catalysts are potential visible-light-driven photocatalysts. The $Bi_2MoO_6$ catalysts prepared using EGME as a solvent showed the highest photocatalytic activity. In addition, the $Bi_2MoO_6$ catalysts prepared at $180^{\circ}C$ showed the highest photocatalytic activity. The PL peaks appeared at about 560 nm at all catalysts and the excitonic PL signal was proportional to the photocatalytic activity for the decomposition of Rhodamin B. This suggests that the stronger the PL intensity, the larger the amount of oxygen vacancies and defects, and the higher the photocatalytic activity.

• Tuberculosis and Respiratory Diseases
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• v.50 no.4
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• pp.450-461
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• 2001

Background : The underlying pathogenesis of radiation-induced lung fibrosis (RTLF) has not been very well defined. However, the role of TGF-$\beta$ in the generation of RTLF has been a major focus because there is an increase in the expression of both the TGF-${\beta}m$-RNA and its protein preceding RTLF lesions. The down stream signal after a TGF-$\beta$ stimulated lung fibrosis includes the activation of many mediators such as Smad and c-Jun N-terminal kinase (JNK) through TAK1. It is we hypothesized that JNK activation may play a pivotal role in RTLF pathogenesis through increased transcription of the fibrogenic cytokines. The present study evaluates JNK activity in alveolar macrophages after irradiation and the relationship between JNK activity and the amount of collagen in the lung tissues. Methods : C57BL/6 mice(20-25 gr, males) received chlorotetracycline(2g/L) in their drinking water 1 week prior to irradiation and continuously there after. The mice were irradiated once with 1400 cGy of $60CO{\gamma}$-ray over the whole chest. The cellular composition of the whole lung bronchoalveoalr lavage fluids(BALF), elastin expression in the lung tissues, the level of hydroxyproline in lung tissues, and an in vitro JNK assay was measured before irradiation and one, four, and eight weeks after irradiation (RT). Results : The volumes of BALF retrieved from instilled 4 mL of saline with 2% heparin were 3.7-3.8 mL for each group. The cell numbers were similar before($4.1{\times}10^4{\pm}0.5{\times}10^4/mL$) and 1 week($3.1{\times}10^4{\pm}0.5{\times}10^4/mL$) after RT. At four and eight weeks after RT, the cell number reached to $14.0{\times}10^4{\pm}1.5{\times}10^4mL$ and $10.0{\times}10^4{\pm}1.3{\times}10^4/mL$, respectively. There we no changes in the lymphocytes and neutrophils population observed in the BALF after RT. The H-E stain of the lung tissues did not show any structural and fibrotic change in the lung tissues at 4 and 8 weeks after RT. In addition, the amount of elastin and collagen were not different on Verhoeff staining of the lung tissues before RT to eight weeks after RT. The hydroxyproine content was measured with the left lung dissected from the left main bronchus. The lung were homogenized and hydrolyzed with 6 N Hel for 12 hours at $110^{\circ}C$ then measured as previously described. The content of hydroxyproline, standardized with a lung protein concentration, reached a peak 4 weeks after RT, and thereafter showed a plateau. AnIn vitro JNK assay using c-$Jun_{1-79}$-GST sepharose beads were performed with the alveolar macrophages obtained from the BAL. JNK activity was not detected prior to RT, However, the JNK activity increased from one week after RT and reached a peak four weeks after RT. Conclusion : JNK may be involved in the pathogenesis because the JNK activity showed similar pattern observed with the hydroxyproine content. However, it is necessary to clarify that the JNK increases the transcription of fibrogenic cyiokines through the transcription factor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1460-1468
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• 2011

This study investigated the quality changes and characteristics (0, 3, 6, 9%) of pound cake made with flour that included gamma irradiated (50 kGy) hot water extracts of Undaria pinnatifida sporophyll (WEUS). The pH of pound cakes decreased with increasing powder concentration, and gamma-irradiated pound cakes had lower pH than non-irradiated pound cakes at the same powder concentrations. The height, volume, specific loaf volume, and baking loss showed no significant differences between control and experimental groups. With increasing powder concentration, the L value of the crust and crumbs decreased, but the a value increased. The b value showed different tendencies between crust and crumb. The crust value was reduced with higher content of WEUS, but the crumb value increased. Gamma-irradiated pound cakes were also less hard than non-irradiated pound cakes. On the other hand, adhesiveness and springiness decreased with increasing powder concentration, but were not significantly different from the control. Also, gumminess and chewiness decreased but not significantly so. The hardness after several days of storage (5, 10, and 15 days) was higher than the control, and the springiness and cohesiveness were significantly reduced with increasing concentration compared to the control. The retrogradation increased in the control group, but it did not in the experimental groups. Results of radical scavenging activity using DPPH indicated that the gamma-irradiated group was higher than the non-irradiated group and it was also higher with higher concentrations of powder. In a sensory evaluation, when compared to the control, pound cake with 3% WEUS was superior in taste, flavor, and overall preference. Therefore, it was found that pound cake with 3% WEUS powder with gamma irradiation of 50 kGy added could improve the yield, taste, and antioxidant activity of pound cake.

• Food Science and Preservation
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• v.19 no.2
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• pp.249-256
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• 2012

The changes in the volatile organic compounds in plum after its electron beam irradiation and storage were determined using the simultaneous distillation extraction method and gas chromatograph-mass spectrometry. There were 44, 46, 45, 47, and 38 volatile compounds in the 0-, 0.25-, 0.5-, 0.75-, and 1 kGy irradiated samples, respectively. Also, the volatile flavor components of the plum that was stored for 30 days were identified as 48, 40, 40, 39, and 40 components. The compositions of the volatile compounds of the control and irradiated samples showed a similarity after the storage. Especially, the more important volatile flavor of the plum was identified as hexanal of the C6compounds, (E)-2-hexenal and (Z)-3-hexenal. In particular, hexanal, (E)-2-hexenal, and (Z)-3-hexen-1-ol increased in all the doses, where as hexanol and (E)-2-hexen-1-ol decreased. Among the lactone compounds, ${\gamma}$-hexalactone, ${\gamma}$-octalactone, and ${\gamma}$-decalactone were identified during the storage period in the raw samples. Hexanonic acid and 2-hexenoic acid were not identified during the storage of the samples, and 2-methylprrole was detected only when the storage samples were irradiated at a dose higher than 0.5kGy. Therefore, it was shown that there was no effect on the variation of the volatile organic component suntil 1 kGy in the plum was irradiated with an electron beam.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.571-578
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• 2001

To evaluate if the apoptotic fragment assay could be used to estimate the dose prediction after radiation exposure, we examined apoptotic mouse crypt cells per 1,000 cells after whole body $^{60}Co$ $\gamma$-rays and 50MeV ($p{\rightarrow}Be^+$) cyclotron fast neutron irradiation in the range of 0.25 to 1 Gy, respectively. The incidence of apoptotic cell death rose steeply at very low doses up to 1 Gy, and radiation at all doses tigger rapid changes in crypt cells in stem cell region. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for the data of apoptotic fragments was obtained by the linear-quadratic model $y=0.18+(9.728{\pm}0.887)D+(-4.727{\pm}1.033)D^2$ ($r^2=0.984$) after $\gamma$-rays irradiation, while $y=0.18+(5.125{\pm}0.601)D+(-2.652{\pm}0.7000)D^2$ ($r^2=0.970$) after neutrons in mice. The dose-response curves were linear-quadratic, and a significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic crypt cells with increasing dose. Both the time course and the radiation dose-response curve for high and low linear energy transfer (LET) radiation modalities were similar. The relative biological effectiveness (RBE) value for crypt cells was 2.072. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morpholoigcal findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis in crypt cells could be a useful in vivo model for studying radio-protective drug sensitivity or screening test, microdosimetric indicator and radiation-induced target organ injury. Since the apoptotic fragment assay is simple, rapid and reproducible in the range of 0.25 to 1 Gy, it will also be a good tool for evaluating the dose response of radiation-induced organ damage in vivo and provide a potentially valuable biodosimetry for the early dose prediction after accidental exposure.