• The Korea Journal of Herbology
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• v.24 no.4
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• pp.95-99
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• 2009

Objectives : This study were carried out to investigate the anti-oxidative activities of $\gamma$-SPE(gamma irradiated shell of Persicae semen extract with ethanol). Methods : Anti-oxidative was measured by DPPH free radical scavenging activities, nitric oxide radical scavenging activities, SOD-like activities, xanthine oxidase radical scavenging activities, nitrite scavenging activities and tyrosinase inhibition activities. Results : Effects of free radial scavenging was increased by irradiation. Tyrosinase inhibition activities was decreased by $\gamma$-SPE. Conclusions : Results suggested that $\gamma$-SPE have a potential as a new anti-oxidative material.

• 전기의세계
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• v.22 no.4
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• pp.7-10
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• 1973

The characteristics of all the instruments and materials used in atomic industry is changed due to radiation damages by the effects of radiation activities. In this study, when the Carbon Resistor, main element of electrical circuits, is irradiated by Gamma-Ray, variations in its electrical properties have been investigated. The following results are obtained: 1) The resistance value in Carbon Resistor is exponentially increased as the quantity of irradiation by Gamma-Ray is increased, but in case of more than 10$^{6}$ R/hr. of quantity of irradiation it has saturated-state value. 2) The rate of change inrestistance value has been independent on the intensity of Gamma-Ray source when Carbon Resistor is irradiated in the same quantity of irradiation. 3) The resistance value in irradiated Carbon Resistor has not been varied with elapse of time. 4) The more the distance from the Carbon Resistor to the Gamma-Ray source the more greatly the resistance value is decreased and that it has been shown that the more quantity of irradiation by Gamma-Ray, the greater the rate of decrease in resistance value. Through the above results it has been concluded that the measurement values obtained by the high-precision instruments in the radiation field have to be corrected with proper consideration to radiation damages.

• Journal of Food Hygiene and Safety
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• v.11 no.1
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• pp.41-50
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• 1996

The yields of solvent fraction of irradiated red ginseng powder were increased in the order of petroleum ether(PE)

• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2353-2360
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• 2020

An anodic electrophoretic deposition (EPD) technique is used to create a uniform TiO₂ thin film coating on boiling thin steel plates (1.1 mm by 90 mm). All of the effective parameters except time of the EPD method are kept constant. To investigate the effect of gamma irradiation on the critical heat flux (CHF), the test specimens were irradiated in a gamma cell to different doses ranging from 100 to 300 kGy, and then SEM and BET analysis were performed. For each coated specimen, the contact angle and capillary length were measured. The specimens were then tested in a boiling pool for CHF and boiling heat transfer coefficient. It was observed that irradiation significantly decreases the maximum pore diameter while it increases the porosity, pore surface area and pore volume. These surface modifications due to gamma irradiation increased the CHF of the nano-coated surfaces compared to that of the unirradiated surfaces. The heat transfer coefficient (HTC) of the nano-coated surfaces irradiated at 300 kGy increased from 83 to 160 kW/(㎡ K) at 885 kW/㎡ wall heat flux by 100%. The CHF of the irradiated (300 kGy) and unirradiated surfaces are 2035 kW/㎡ and 1583 kW/㎡, respectively, an increase of nearly 31%.

• The Journal of the Korean Society for Microbiology
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• v.8 no.1
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• pp.37-42
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• 1973

For the preparation of non-infective vaccine against typhoid fever, the authors had carried out an investigation on the possibilities of using $^{60}Co\;{\gamma}$-ray irradiation for the inactivation of Salmonella typhi Ty 2. The following results were obtained. 1) Chicks shortly after hatching were higher susceptible than mice to intracerebral injection with S. typhi. 2) In safety test on experimental animal, $^{60}Co\;{\gamma}$-ray irradiated vaccines demonstrated no clinical symptom while the phenol treated vaccines revealed several cases of narcosis by intraperitoneal injection in chicks. 3) The rabbit antisera immunized with $^{60}Co\;{\gamma}$-ray irradiated and phenol treated vaccine revealed almost same agglutinin titers to each other. 4) In potency test in chicks, there was no significance in the protective capacity between $^{60}Co\;{\gamma}$-ray irradiated and phenol treated vaccines.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.341-346
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• 2006

This study was performed to examine the effects of ${\gamma}$-irradiation on the volatile flavor compounds of dried leeks (Alliums tuberosum R.). Volatile compounds of dried leeks were extracted using simultaneous steam distillation and extraction (SDE), and analyzed by gas chromatography/mass spectrometry (GC/MS). Forty-one, 51, 45, and 42 compounds were tentatively identified in control, 1, 3, and 10 kGy irradiated samples, respectively. The constituents of flavor compounds in irradiated dried leeks were similar to non-irradiated samples. However, the intensities of the peaks were clearly different between them. Sulfur-containing compounds were detected as dominant compounds in all samples and their amounts decreased after ${\gamma}$-irradiation. ${\gamma}$-Irradiation reduced the total concentration of volatile compounds from leeks by 23.19, 15.09, and 30.23% at 1, 3, and 10 kGy doses, respectively.

• Journal of Radiation Industry
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• v.4 no.1
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• pp.47-51
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• 2010

Centipedegrass is a warm season turfgrass in the world. Chlorogenic acid (CA) is one of the important compounds present in the leaf of centipedegrass and already known as an antioxidant, CA has become a key resistance against insect pests and bacteria pathogens of agricultural and horticultural plants during seedling stage. Furthermore, CA is accumulated by abiotic stress such as an UV irradiation. In present study, we investigated enhancement of the level of CA upon gamma irradiation in centipedegrass. The high performance liquid chromatography (HPLC) data analysis showed an approximately increasing of the CA levels from among the irradiated samples. However, plants irradiated at 50 Gy showed a constant increase in the CA level (0.0066 to $0.114mg\;ml^{-1}$ and 0.0258 to $0.2211mg\;ml^{-1}$, respectively) from $3^{rd}$ to $15^{th}$ day among one and three month irradiated plants compared to control. The present study, indicates an increase in the CA level upon gamma irradiation, suggests strategy for conferment of strong resistance in seedling stage plants by gamma irradiation as simplicity and cheaply method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1192-1200
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• 2004

Gamma irradiations at 5 or 10 kGy were applied to salted and fermented anchovy sauce, for improving the hygiene Quality and evaluating the genotoxicological safety. In vitro genotoxicological safety of irradiated sauces was evaluated by Salmonella Typhimurium (TA98, TA100, TAI535 and TAI537) and E. coli WP2 uvrA, reversion assay, SOS chromotest (Escherichia coli PQ37), and chromosome aberration test (Chinese hamster lung fibroblast cells) in the absence or presence of an exogenous metabolizing system (S9 mix). The gamma-irradiated samples were not significantly different from nonirradiated-control for three in vitro tests (p＜0.05). ：In vivo micronucleus test using ICR mice (male) was not significantly different from the control at p＜0.05. The salted and fermented anchovy sauce exposed to 5 or 10 kGy-gamma ray revealed negative results in these three in vitro mutagenetic tests and in vivo micronucleus test upto 50,000 $\mu$g/plate, respectively. The results indicated that 5 or 10 kGy gamma-irradiated salted and fermented anchovy sauces did not show any mutagenicity.

• Rapid Communication in Photoscience
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• v.1 no.1
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• pp.21-24
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• 2012

Influence of gamma rays on the cyanobacterium Synechocystis sp. PCC 6803 cells was investigated in terms of a bidirectional hydrogenase, which is encoded by hoxEFUYH genes and responsible for biohydrogen production. Irradiated cells revealed a substantial change in stoichiometry of photosystems at one day after gamma irradiation at different doses. However, as evaluated by the maximal rate of photosynthetic oxygen evolution, maximal photochemical efficiency of photosystem II, and chlorophyll content, net photosynthesis or photosynthetic capacity was not significantly different between the control and irradiated cells. Instead, transcription of hoxE, hoxH, or lexA, which encodes a subunit of bidirectional hydrogenase or the only transcriptional activator, LexA, for hox genes, was commonly enhanced in the irradiated cells. This transcriptional enhancement was more conspicuously observed immediately after gamma irradiation. In contrast, hydrogenase activities were found to somewhat lower in the irradiated cells. Therefore, we propose that transcription of hox genes should be enhanced by gamma irradiation in a LexA-mediated and possibly photosynthesis-independent manner and that this enhancement might not induce a subsequent increase in hydrogenase activities, probably due to the presence of post-transcriptional and/or post-translational regulatory mechanisms.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1488-1494
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• 1999

Effect of ${\gamma}-irradiation$ on the SDS-PAGE pattern, secondary structure content, the solubility of commercial soy protein isolate (SPI) and whey protein concentrate (WPC) was investigated. The change in the subunit molecular weight of SPI and WPC irradiated in aqueous solution or dried state was studied using SDS-PAGE. The SDS-PAGE pattern of SPI irradiated in aqueous solution revealed the fragmentation and aggregation of the subunit protein. For WPC irradiated in aqueous solution. fragmentation of the subunit protein up to 10 kGy was observed. In contrast, ${\gamma}-irradiation$ of SPI and WPC in dried state did not cause any significant changes in the SDS-PAGE pattern. The change In the secondary structure of irradiated SPI and WPC solution was studied using circular dichroism. The aperiodic structure content of SPI and WPC solution increased at higher irradiation doses, which suggests that ${\gamma}-irradiation$ caused the disruption of the ordered structure of SPI and WPC solution. Gamma-irradiation also caused the change in solubility of SPI and WPC in dried state.