• Nuclear Engineering and Technology
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• 제11권2호
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• pp.105-110
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• 1979

3종의 유기물을 첨가한 산성, 알카리성 답 토양에 방사성 아연비료($^{65}ZnSO_4$)를시용(施用)하고 $^{60}Co$ gamma선을 조사(照射)하였을때 시용한 $^{65}Zn$의 고정(固定)과 방출(放出)에 어떤 영향을 주는가를 보기 위하여 실험실내에서 항온방치 실험을 행한 결과를 요약하면 다음과 같다. 산성, 알카리성 답 토양에 시용한 $^{65}ZnSO_4$는 이들 토양에 고정되므로 DTPA용액에의 가용성 $^{65}Zn$ 는 방치시간이 경과 할수록 감소되다가 항온방치 4주 부터 고액상(固液相)간에 평형을 유지하게된다. 이 평형상태하에서 $^{65}ZnSO_4$의 대부분은 고상(固相)에 흡착 고정되는데 그 정도는 산성인 금곡토양에서는 $^{65}Zn$의 89% (방사능 기준) 이었고, 알카리성인 석회암질 제천토양에서는 93.7% 이었다. 산성. 알카리성 답 토양에 gamma선을 조사(照射)하면 $^{65}Zn$의 고정은 감소되므로 가용성 $^{65}Zn$ 는 증가한다. 고정된 $^{65}Zn$의 DTPA 용액에의 가용정도는 산성인 금곡토양에서는 38.9% 이었고 알카리성 석회암질 제천토양에서는 9.5%에 불과 하였다. 고정된 $^{65}Zn$의 gamma선 조사(照射)에 의한 방출은 답 토양의 pH에 밀접한 관계가 있었다. 즉 고정된 $^{65}Zn$의 방출은 pH가 얕은 산성토양에서 현저했고 알카리성 토양에서는 적었다. 금곡토양에 gamma선을 조사하면 $^{65}Zn$의 유효도가 커지는 것으로 봐서 산성조건에서는 고정된 아연은 더 가용화 된다고 본다. 유기물 급원(給源)별 방사선 영향 차이는 인정되지 않았다. 그러나 gamma선을 조사하지 않았을 때 Glucose 처리는 Cellulose나 생고분말(生藁粉末)을 첨가했을 때 보다 DTPA 가용성 $^{65}Zn$은 더 방출(放出)되었다.

• Journal of Biosystems Engineering
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• 제38권2호
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• pp.87-94
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• 2013

Purpose: Pineapple is now the third most important tropical fruit in world production after banana and citrus. Phytosanitary irradiation is recognized as a promising alternative treatment to chemical fumigation. However, most of the phytosanitary irradiation studies have dealt with physiochemical properties and its efficacy. Accurate dose calculation is crucial for ensuring proper process control in phytosanitary irradiation. The objective of this study was to optimize phytosanitary irradiation treatment of pineapple in various radiation sources using Monte Carlo simulation. Methods: 3-D geometry and component densities of the pineapple, extracted from CT scan data, were entered into a radiation transport Monte Carlo code (MCNP5) to obtain simulated dose distribution. Radiation energy used for simulation were 2 MeV (low-energy) and 10 MeV (high-energy) for electron beams, 1.25 MeV for gamma-rays, and 5 MeV for X-rays. Results: For low-energy electron beam simulation, electrons penetrated up to 0.75 cm from the pineapple skin, which is good for controlling insect eggs laid just below the fruit surface. For high-energy electron beam simulation, electrons penetrated up to 4.5 cm and the irradiation area occupied 60.2% of the whole area at single-side irradiation and 90.6% at double-side irradiation. For a single-side only gamma- and X-ray source simulation, the entire pineapple was irradiated and dose uniformity ratios (Dmax/Dmin) were 2.23 and 2.19, respectively. Even though both sources had all greater penetrating capability, the X-ray treatment is safer and the gamma-ray treatment is more widely used due to their availability. Conclusions: These results are invaluable for optimizing phytosanitary irradiation treatment planning of pineapple.

• 동아시아식생활학회지
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• 제18권6호
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• pp.1056-1062
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• 2008

To evaluate the effect of irradiation on restructured pork jerky containing paprika and Japanese apricot extracts, the quality of protein was determined in vitro based on the formation of trypsin indigestible substrate inhibitor (TIS) and the computed protein efficiency ratio (C-PER) as determined based on the protein digestibility and amino acid analysis. In addition, we compared the effects of electron beam irradiation to those of gamma irradiation. Approximately 3% of the moisture content of pork jerky was reduced in response to irradiation with 3kGy administered using an electron beam however, no additional reduction was observed in samples that were subjected to higher doses of irradiation. In addition, there were no notable differences in the crude protein and fat content of pork jerky samples that were subjected to irradiation, regardless of dose. Furthermore, the total amino acids profiles did not change in response to electron beam irradiation. However, the in vitro protein digestibility increased by 7% in response to 3kGy of electron beam irradiation and 5kGy of gamma irradiation, but no significant changes in digestibility were not observed in response to treatment with higher doses. TIS quantified as trypsin inhibitors were formed in response to irradiation using the electron beam (3kGy) and gamma rays (5kGy), although there was a slight reduction in the production of TIS inhibitors in samples irradiated with higher doses. Moreover, only samples irradiated with 10kGy (electron beam and gamma ray) showed higher TBA values than those of the control samples. Finally, the C-PERs $(2.50{\sim}2.60)$ were greater in all of the irradiated pork jerky samples than in the control samples (2.22). Taken together, these results suggest that electron beam irradiation and the incorporation of extracts (paprika and Japanese apricot) may be useful methods of improving the nutritional quality of pork jerky.

• Archives of Pharmacal Research
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• 제20권3호
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• pp.212-217
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• 1997

Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of ${\gamma}$-rays (0.01 Gy) 4 or 20 hrs prior to high dose ${\gamma}$-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose .gamma.-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-.betha.-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose ${\gamma}$-ray irradiation to high dose ${\gamma}$-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.

• 방사선산업학회지
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• 제6권1호
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• pp.23-29
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• 2012

In this study, we investigated the genetic variation in the general of monocot model plant (rice) in response to various ionizing irradiations including gamma-ray, ion beam and cosmic-ray. The non-irradiated and three irradiated (200 Gy of gamma-ray and 40 Gy of ion beam and cosmic-ray) plants were analyzed by AFLP technique using capillary electrophoresis with ABI3130xl genetic analyzer. The 29 primer combinations tested produced polymorphism results showing a total of 2,238 bands with fragments sizes ranged from 30 bp to 600 bp. The number of polymorphism generated by each primer combinations was varied significantly, ranging from 2 (M-CAC/E-ACG) to 158 (M-CAT/E-AGG) with an average of 77 bands. Polymorphic peaks were detected as 1,269 with an average of 44 per primer combinations. By UPGMA (Unweighted Pair Group Method using Arithmetic clustering) analysis method, the clusters were divided into non-irradiated sample and three irradiated samples at a similarity coefficient of 0.41 and three irradiation samples was subdivided into cosmic-ray and two irradiation samples (200 Gy of gamma-ray and 40 Gy of ion beam) at similarity coefficient of 0.48. Similarity coefficient values ranged from 0.41 to 0.55.

• 대한수의학회지
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• 제12권1호
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• pp.1-5
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• 1972

In oder to investigate the effects of cobalt-60 gamma ray irradiation on the body gains of rabbits aging approximately 50-day-old rabbits were subjected to single whole-body gamma irradiation externally. The results obtained were as follows: 1. There were significant differences of the body gains between control and treated groups except the 100 rads gamma-rays exposure group. 2. There were no differences in body gains between male and female rabbits. 3. Generally, the relation between gamma irradiated doses and the growth rates of rabbits were inversly proportional. 4. The $LD_{50}$ of the rabbits was 600 rads in case of single external whole-body gamma irradiation.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.342-345
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• 2001

A bacterial strain PH-4, which produces an enzyme catalyzing the degradation of crosslinked poly(${\gamma}$-glutamic acid) hydrogels, was isolated and identified as a Flavobacterium sp. The enzyme was obtained by the sonication of the bacterial cells preincubated in a Bouillon medium with shaking, without adding of poly(${\gamma}$-glutamic acid) as an inducer. The products of the hydrogel degraded by the crude enzyme agreed closely with the depolymerized materials in SDS-polyacrylamide gel electrophoresis using methylene blue staining, and with a glutamic acid monomer on thin-layer chromatography, thereby suggesting that strain PH-4 produced a kind of exohydrolase.

• Journal of Radiation Protection and Research
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• 제33권4호
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• pp.143-150
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• 2008

In this study, we examined the effect of hydroxyl radical generated by $\gamma$-ray and UV irradiation on shrinkage of vitreous body. Change in gel ratio of vitreous body and change in the properties of its components (collagen, sodium hyaluronate) were analyzed. By comparing these results, the amount of hydroxyl radical, which induces the considerable shrinkage of vitreous body, was evaluated from theoretical calculation based on experimental condition and some reported kinetic parameters. It was concluded that the integrated amount of hydroxyl radical required to liquefy half of the vitreous body (Vitreous body gel ratio = 50%) was estimated as $140\;{\mu}molg^{-1}$ from $\gamma$-ray irradiation experiment. Also, from UV irradiation experiment result, it was confirmed that the effect of hydroxyl radical is larger than that of other reactive species. The causes of shrinkage of vitreous body are supposed as follows, 1) decrease in viscosity by cleavage of glycoside bond in sodium hyaluronate, 2) leaching of collagen from vitreous body and 3) leaching of crosslinked products and scission products of collagen.

• 방사선산업학회지
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• 제4권4호
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• pp.385-389
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• 2010

In this study, the effect of the concentration of carboxymethylcellulose (CMC) solution on the degradation by irradiation was investigated. The CMC solutions with different concentrations of 3%, 4%, 5%, 6% and 7% were irradiated at the doses of 5, 10, 15, 20, 25 and 30 kGy with gamma ray or electron beam, and the viscosity of CMC solution was measured. The viscosity of the CMC solutions was decreased with an increase in the irradiation dose, but the extent of the degradation by an irradiation was found to be decreased with an increase of the CMC concentration in the solution. The dependency of the irradiation sources showed that an electron beam radiation had degraded the CMC less severely than gamma ray.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.533-534
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• 2009