• Nuclear Engineering and Technology
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• v.15 no.1
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• pp.1-10
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• 1983

By controlling both the means of grafting and the cast-solution components, no degradation and dimensional change of radiation-induced graft polymerization were found. The electric resistance of styrene-cellulose acetate grafts increases with increasing styrene content, while those for the hydrophilic monomers show no marked effect. In comparison with the grafted cellulose acetate membrane by simultaneous irradiation method, the appearance of the grafted membrane by post-polymerization method was not markedly changed irrespective of the percent of grafting and radiation dose of electron beam or ${\gamma}$-ray. The combination of crosslinking agents such as divinyl benzene (OB) or trimethyl propane triacrylate (TMPT) in the VP:St:BPO system leads to gradual increase of the percent of grafting. The activation energy for grafting of St:VP:BPO solution onto cellulose acetate membrane was determined to be about 21.8 Kcal/mole over the range of 55$^{\circ}$-8$0^{\circ}C$. The initial rate of grafting (in %/hr) is proportional to the power 0.76 for dose intensities.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.139-149
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• 2005

In order to study about the lobule and layer formation and cell migration of the mouse cerebellum from at the birth to 15th day effected by 2.5, 5 and 10 Gy r-raddiation at the 19th pregnancy. The routine tissue preparation and staining procedure, Immunohistochemical staining method by the several antibody and western brotting method were utilized from the birth to the15th day. The results were as followings. 1. The body and cerebellum weights were more slowly increase of the the 2.5 Gy, 5 Gy and 10 Gy irradiation group compare to the control group, and the health condition of the 2.5 Gy group was a little bad. but the 10 Gy group was more severe and begun to die from the 12th day after birth. 2. The thickness, proliferation and migration of the 2.5, 5 and 10 Gy irradiated external granular cells from the maginal zone to the medullary area forming the molecular layer from the 6th day to the 15th day after birth were thinner, weaker and more slower according to the radiated dosages than the control group in the cresyl violet staining. 3. The proliteration, migration and lobulation of the 5 Gy radiated groups from the first day to the 15th day after birth were more weak, incomplete and irregular shape in the immunostaining with Dab, Cdk5, P35, calbindin and Zebrin antibody. 4. In the western blotting analysis using the Reelin, Dab, Cdk5 and P35 antibody. The Bands were in the 60 KD, 80 KD, 33 KD and 35 KD, and there were no differences between the control and irradiated groups in the molecular band except the Reelin. 5. As a results, the proliferation and migration of the outer granular and purkinje cells, and lobulation of the cerebellum by the several dosaege of the ${\gamma}$-ray radiation were proportionally incomplete according to dosage.

• Journal of Pharmaceutical Investigation
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• v.4 no.4
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• pp.17-25
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• 1974

1. Neutron acivation analysis of arsenic contained in Korean human liver was studied in the view point of forensic chemistry, using 12 corpses. A sample of 1g was irradiated for 30 mins. in a neutron flux of $1.2{\times}10^{12}n/cm^2/sec$, followed by nitric-sulfuric acid digestion and then by Gutzeit separation. Radio activity was detected by it's scintillation counter. The arsenic content in the liver was found to be $0.01{\mu}g/g$ to $0.15{\mu}g/g$. 2. A rapid and convenient method for the radiochemical determination of minerals by neutron activation analysis was established. After neutron irradiation to the standard soln. of Cu and Mn in pneumatic tube (neutron flux : $1.2{\times}10^{12}n/cm^2/sec$), Cu and Mn were determined by estimating the ratio of the widths under energy peak area in ${\gamma}-ray-spectrogram$. When the standard soln. of Mn and Cu is irradiated for 15 mins. to 18 hrs., recovery test shows that the relative errors are 5.1% and 4.5% for copper and manganese, respectively.

• Journal of radiological science and technology
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• v.11 no.1
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• pp.71-77
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• 1988

To improve the storage method for kimchi, optimal ripening kimchi was irradiated with doses of 1, 3, 5kGy Co-60gamma radiation, followed by the microbiological, physicochemical and senosory evaluations during storage at $5^{\circ}C$. 1. Total aerobic count increased in the beginning of storage and then decreased slowly as the number of total lactobacilli (anaerobe) increased. The above, total aerobic and lactobacilli were reduced by 1 to 3 log cycles with irradiation and at the 90th day after storage the number of total lactobacilli remained $1.30{\times}10^{8}$ per ml in 3 kGy irradiated group. Irradiation treatment at 3 kGy sterilized coliforms and molds contaminating the sample as the level of $2.0{\times}10^{4}$ per ml and $5.4{\times}10^{2}$ per ml respectively and no apparent growth was observed in both control and 1 kGy irradiated groups after 20 days of storage. The population of yeast, $3.5{\times}10^{3}$ per ml initially, increased steadily during kimchi storage and at 90 days of storage the number was shown to be $5.6{\times}10^{4}$ per ml and $6.5{\times}10^{2}$ per ml in control and 3 kGy irradiated groups, respectively. 2. In the physicochemical changes during kimchi storage, pH, acidity and volatile acid of non-irradiated control at the 45th day after storage were 4.0, 0.7% and 0.066%, while those of 3 kGy irradiated group were 4.2, 0.59 and 0.06% at the 90th day of storage, respectively. The reducing sugar content of all stored samples changed inversely total acidity content, indicating irradiation delayed the changes of them. The amount of ascorbic acid decreased gradually with the storage time and irradiation dose increase. Textural parameters of 3 kGy irradiated group were superior to those of other groups at the latter stage of storage. 3. Sensory evaluations showed that 3 kGy irradiation was the optimum dose level to extend the shelf-life of kimchi more than two months as compared to control.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.136-141
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• 2010

This study attempted to determine whether Photostimulated Luminescence (PSL) is applicable for the detection of post-irradiated foods by measuring the PSL photon counts of unirradiated and irradiated dried spices and herbs. A total of 19 dried spices and herbs was irradiated with a $^{60}Co$ $\gamma$-ray source at 1, 5 and 10 kGy followed by measurement of PSL photon. The photon counts of unirradiated samples below 700 correspond to negative. Fifteen samples irradiated over 1 kGy showed photon counts of more than 5,000, indicating irradiation treatment. Intermediate counts (photon count 700-5,000) were observed in irradiated white/black pepper, nutmeg and cinnamon bark at 10 kGy. These results suggest that it is possible to detect whether dried spices and herbs were irradiated by analyzing PSL, with the exception of white/black pepper, nutmeg and cinnamon bark. Irradiated white/black pepper, nutmeg and cinnamon bark containing low levels of minerals were not sensitive to PSL. Therefore, further investigation is sugguested to be performed by Thermoluminescence (TL) analysis or another validated or standardized method.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.69-74
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• 2013

This study examined radiation detection characteristics of spices (cumin, caper and turmeric), other small fruits (hut-gae berry and boxthorn), and pollen extract product. Each samples were irradiated at dose of 1, 5, and 10 kGy and analyzed by the thermoluminescence (TL) and electron spin resonance (ESR) methods. To compare between non-irradiated and irradiated food, all samples were irradiated with $^{60}Co$ gamma-ray source. In TL analysis, most of samples could be applied to detect irradiated foods because of showing TL ratio above 0.1. The glow curves examined by TL method were estimated in the range of $150{\sim}250^{\circ}C$ in irradiated samples. In ESR measurements, the intensity of ESR signal (single-line) increased as the increase of irradiation dose. In particular, the specific ESR signals of irradiation-induced radical were detected in hut-gae berry and pollen extract product. As a results, it is considered that TL and ESR methods can be used to detect both hut-gae berry and pollen extract product. But cumin, caper, turmeric and boxthorn irradiated with gamma ray could be detected only by TL method. It is concluded that TL and ESR methods are suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.

• Journal of the Korean Chemical Society
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• v.37 no.11
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• pp.961-966
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• 1993

The determination of noble metals such as Ir, Au and Ag in the ancient coins has been studied. For the measurement of the activity of $^{192}Ir,\;^{198}Au\;and\;^{110m}Ag$, radiochemical separations including solvent extraction and ion-exchange chromatography were applied to reduce the interference of high energy ${\gamma}$-ray emitted from various radionuclides with long half-life. As a results, $10^{-11}$ g/g level of Ir could be detected and it was found that the three kinds of the detection limits, i.e., critical, detection, quantitative limit, calculated by the method proposed by Currie, were enhanced. Prior to the re-irradiation with neutron, inactive carrier was added in order to determine the recovery yield of Ir in the radiochemical separation. The average recovery yields of Ir, Au and Ag in the 5 coins were 65.3%, 98.5%, 99.5%, respectively.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.12-12
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• 2017

Genetic improvement in potato can be carried out through several approaches, as sexual crosses, somatic hybridization, mutation and genetic engineering. Although the approach is different, but the goal is the same, to get a superior cultivar. Mutation and genetic engineering are very interesting methods for genetic improvement of potato plants. Mutation by gamma-ray irradiation have been performed to get some new potato cultivars which are more resistant to disease and have higher productivity. We have carried out a mutation of some potato cultivars and obtained some excellent clones to be potentially released as new superior cultivars. By the mutation method, we have released one potato cultivar for the French fries industry, and we registered one cultivar of potato for chips, and two cultivar for vegetable potatoes. Actually we are doing multi-location trial for three clones to be released as new cultivars. Through genetic engineering, several genes have been introduced into the potato plant, and we obtained several clones of transgenic potato plants. Transgenic potato plants containing FBPase gene encoding for fructose bisphosphatase, have a higher rate of photosynthesis and higher tuber productivity than non-transgenic plants. This result suggests that FBPase plays an important role in increasing the rate of photosynthesis and potato tuber productivity. Some transgenic potatoes containing the Hd3a gene are currently being evaluated for their productivity. Over expression of the Hd3a gene is expected to increase tuber productivity and induce flowering in potatoes. Transgenic potato plants containing MmPMA gene encoding for plasma membrane ATPse are more tolerant to low pH than non-transgenic plants, indicating that plasma membrane ATPase plays an important role in the potato plant tolerance to low pH stress. Transgenic potato plants containing c-lysozyme genes, are highly tolerant of bacterial wilt diseases caused by Ralstonia solanacearum and bacterial soft rot disease caused by Pectobacterium carotovorum. Expression of c-lyzozyme gene plays an important role in increasing the resistance of potato plants to bacterial diseases.

• Radiation Oncology Journal
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• v.19 no.3
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• pp.252-258
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• 2001

Purpose : The objectives of this study are to investigate the significance of apoptotic death compared to total cell death after $\gamma-ray$ irradiation in human H&N cancer cell lines and to find out correlation between apoptosis and radiation sensitivity. Materials and method : Head and neck cancer cell lines (PCI-1, PCI-13, and SNU-1066), leukemia cell line (CCRF-CEM), and fibroblast cell line (LM217) as a normal control were used for this study. Cells were irradiated using Cs-137 animal experiment irradiator. Total cell death was measured by clonogenic assay. Annexin-V staining was used to detect the fraction of apoptotic death. Results : Surviving fraction at 2 Gy (SF2) were 0.741, 0.544, 0.313, 0.302, and 0.100 for PCI-1, PCI-13, SNU-1066, CCRF-CEM, and LM217 cell lines, respectively. Apoptosis was detected in all cell lines. Apoptotic index reached peak value at 72 hours after irradiation in head and neck cancer cell lines, and that was at 24 hours in CCRF-CEM and LM217. Total cell death increased exponentially with increasing radiation dose from 0 Gy to 8 Gy, but the change was minimal in apoptotic index. Apoptotic fractions at 2 Gy were $46\%,\;48\%,\;46\%,\;24\%,\;and\;19\%$ and at 6 Gy were $20\%,\;33\%,\;35\%,\;17\%,\;and\;20\%$ for PCI-1, PCI-13, SNU-1066, CCRF-CEM, and LM217, respectively. The radioresistant cell lines showed more higher apoptotic fraction at 2 Gy, but there was not such correlation at 6 Gy. Conclusion : All cell lines used in this study showed apoptosis after irradiation, but time course of apoptosis was different from that of leukemia cell line and normal fibroblast cell line. Reproductive cell death was more important mode of cell death than apoptotic death in all cell lines used in this study. But there was correlation between apoptotic fraction and radiation sensitivity at 2 Gy.

• The Korean Journal of Nuclear Medicine
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• v.25 no.2
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• pp.286-293
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• 1991

$^{123}I$, which is applied for the thyroid and other in vivo kinetic study, has a special role in life sciences. The 159 KeV $\gamma-ray$ from $^{123}I$ is almost ideally appropriate for the current imaging instrumentation. Its decay mode (electron capture) and short half-life (13.3 hr) reduced the burden of radiation dose to the patients, and its chemical property makes it easy to synthesize the labelling compounds. In this experiment, the production of $^{123}I$ via the nuclear reaction $^{124}Te(p,2n)^{123}I$ with 28 MeV protons was sutdied. $TeO_2$ is used as a target material, because it has good physical properties. The target was prepared with $TeO_2$ powder and was molten into a ellipsoidal cavity (a=14 mm, b=10 mm, $270.8mg/cm^2$ thick) of pure platinum. The irradiation was carried out in the external proton beam with incident energies range from 28 MeV to 22 MeV, and current was $30{\mu}A$. The loss of $TeO_2$ target was significantly reduced by using $4\pi-cooling$ system in irradiation. The dry distillation method was adopted for the separation of $^{123}I$ from irradiated target, and when it was kept 5 minutes at $780^{\circ}C$, its result was quantitative. The loss of the target material $(TeO_2)$ was below 0.2% for each production run and $^{123}I$ from the dry distillation apparatus was captured with 0.01 N NaOH in $Na^{123}I$ form, then the pH of the solution was adjusted to $7.5\sim9.0$ with HC1/NaOH. The $Na^{123}I$ solution was passed through $0.2{\mu}m$ membrane filter, and sterilized under high pressure and temperature for 30 minutes. The production of $^{123}I$ is acceptable for clinical application based on the quality of USP XXI.