• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.4
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• pp.713-716
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• 2002

Biogenic amine levels in irradiated doenjang, Korean fermented soybean paste, were investigated during fermentation at $25^{\circ}C$ for 12 weeks. Biogenic amines detected in doenjang were putrescine, cadaverine, tryptamine, $\beta$-phenylethylamine, spermidine, spermine, histamne, tyramine and agmatine. Agmatine showed the most highest level among biogenic amines detected in doenjang during fermentation. Most biogenic amines, such as putrescine, cadaverine, tryptamine, $\beta$-phenylethylamine, spermidine, histamne and tyramine, significantly decreased 20~60% by gamma irradiation during fermentation, while spermine and agmatine did not. Therefore, gamma irradiation can be applied to inhibit the biogenic amines formation in doenjang during fermentation.

• BMB Reports
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• v.33 no.2
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• pp.133-137
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• 2000

To elucidate the effect of oxygen radicals on the molecular properties of proteins, the secondary and tertiary structure and molecular weight size of BSA and ${\beta}$-lactoglobulin were examined after irradiation of proteins at various doses. Gamma-irradiation of protein solutions caused the disruption of the ordered structure of protein molecules as well as degradation, cross-linking, and aggregation of the polypeptide chains. As a model system, BSA and ${\beta}$-lactoglobulin were used as a typical ${\alpha}$-helical and a ${\beta}$-sheet structure protein, respectively. A circular dichroism study showed that the increase of radiation decreased the ordered structure of proteins with a concurrent increase of aperiodic structure content. Fluorescence spectroscopy indicated that irradiation quenched the emission intensity excited at 280 nm. SDS-PAGE and a gel permeation chromatography study indicated that radiation caused initial fragmentation of proteins resulting in a subsequent aggregation due to cross-linking of protein molecules.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1747-1752
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• 2006

Allergic inflammation results from stimulation of ${\beta}$-hexosaminidase secretion, increased calcium influx, and activation of MAPK pathways. Some fractions of Chamaecyparis obtusa decreased secretion of ${\beta}$-hexosaminidase, calcium influx, ROS, and phosphorylation of ERK. These results suggest that Chamaecyparis obtusa would be valuable for development of allergy therapeutics.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.159.1-159.1
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• 2003

This study deals with the radiation protection effect of the pretreatment of $\beta$-carotene and combination with selenium on the DNA damage in mice after whole body ${\gamma}$-irradiation. This was obtained the radioprotective effect by evaluation of DNA damage levels in mice spleen and blood after irradiation. Six-week-old ICR male mice were administrated with $\beta$-carotene and combination with selenium orally once a day for 5 days and then irradiated with 8.0 Gy of $\gamma$-ray at a dose rate of 1.0 Gy/min. (omitted)

• Radiation Oncology Journal
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• v.24 no.4
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• pp.280-284
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• 2006

$\underline{Purpose}$: To evaluate biological characteristics of neutron beam generated by MC50 cyclotron located in the Korea Institute of Radiological and Medical Sciences (KIRAMS). $\underline{Materials\;and\;Methods}$: The neutron beams generated with 15 mm Beryllium target hit by 35 MeV proton beam was used and dosimetry data was measured before in-vitro study. We irradiated 0, 1, 2, 3, 4 and 5 Gy of neutron beam to EMT-6 cell line and surviving fraction (SF) was measured. The SF curve was also examined at the same dose when applying lead shielding to avoid gamma ray component. In the X-ray experiment, SF curve was obtained after irradiation of 0, 2, 5, 10, and 15 Gy. $\underline{Results}$: The neutron beams have 84% of neutron and 16% of gamma component at the depth of 2 cm with the field size of $26{\times}26\;cm^2$, beam current $20\;{\mu}A$, and dose rate of 9.25 cGy/min. The SF curve from X-ray, when fitted to linear-quadratic (LQ) model, had 0.611 as ${\alpha}/{\beta}$ ratio (${\alpha}=0.0204,\;{\beta}=0.0334,\;R^2=0.999$, respectively). The SF curve from neutron beam had shoulders at low dose area and fitted well to LQ model with the value of $R^2$ exceeding 0.99 in all experiments. The mean value of alpha and beta were -0.315 (range, $-0.254{\sim}-0.360$) and 0.247 ($0.220{\sim}0.262$), respectively. The addition of lead shielding resulted in no straightening of SF curve and shoulders in low dose area still existed. The RBE of neutron beam was in range of $2.07{\sim}2.19$ with SF=0.1 and $2.21{\sim}2.35$ with SF=0.01, respectively. $\underline{Conclusion}$: The neutron beam from MC50 cyclotron has significant amount of gamma component and this may have contributed to form the shoulder of survival curve. The RBE of neutron beam generated by MC50 was about 2.2.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.172-181
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• 2015

This study intends to improve the radiation safety management and the recognition for handling radiation using structured questionnaires to dental hygienists working at Jeollabuk-do from September 1 to October 31 in 2014. As a result, 63% of respondents have not received education for radiation safety management. Moreover, the practical degree for radiation safety management was $2.58{\pm}1.11$, while the degree of knowledge was $3.74{\pm}0.83$ of total 5.0. The results of insecurity for radiation danger were high as $3.88{\pm}0.92$, and insecurity for fetus during pregnancy shows the highest value as $4.43{\pm}0.71$. From the results of statistical significance level, the knowledge degree of radiation safety management is affected by total numbers of radiograpy for a day (p<0.05), and the practical degree of radiation safety management is affected by age group, academic background, monthly income, continuous service year, practice area, present position, and status of radiography in present (p<0.05). In addition, the knowledge degree of radiation safety management have a negative correlation (r=-0.232) with the practical degree, but have a positive correlation (r=0.262) with the insecurity for radiation danger. The high knowledge degree of radiation safety management (${\beta}=0.252$, p<0.001) and the short radiography work period (${\beta}=-0.341$, p<0.05) were the influential factors to the insecurity for radiation danger. Consequently, countermeasures are necessary to encourage dental hygienists to put their radiation safety management knowledge into the practice and to reduce the insecurity degree for radiation danger. Furthermore, it is important to prevent psychological and physical risks by radiation exposure through the improvement of radiation safety management level and recognition for handling radiation to improve medical environment.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.193-203
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• 1993

In understanding radiosensitivity a new concept of inherent radiosensitivity based on individuality and heterogeneity within a population has recently been explored. There has been some discussion of possible mechanism underlying differences in radiosensitivity between cells. Ataxia telangiectasia (AT), a rare autosomal recessive genetic disorder, is characterized by hypersensitivity to ionizing radiation and other DNA damaging agents at the cellular level. There have been a lot of efforts to describe the cause of this hypersensitivity to radiation. At the cellular level, chromosome repair kinetics study would be an appropriate approach. The purpose of this study was to better understand radiosensitivity En an approach to investigate kinetics of induction and repair of $G_2$ chromatic bleaks using normal, AT heterozygous (ATH), and AT homozygous lymphoblastoid cell lines. In an attempt to estimate initial damage, $9-{\beta}-D-arabinosyl-2-fluoroadenine,$ an inhibitor of DNA synthesis and repair, was used in this study. It was found from this study that radiation induces higher chromatid breaks in AT than in normal and ATH cells. There was no significant differences of initial chromatid breaks between normal and ATH cells. Repair kinetics was the same for all. So the higher level of breaks in AT $G_2$ cells is thought to be a reflection of the increased initial damage. The amount of initial damage correlated well with survival fraction at 2 Gy of cell survival curve following radiation. Therefore, the difference of radiosensitivity in terms of $G_2$ chromosomal sensitivity is thought to result from the difference of initial damage.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.63-63
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• 2023

Sugar beet (Beta vulgaris L.) is one of the most important sugar crops and provides up to 30% of the world's sugar production. In this study, we mainly performed RNA-sequencing to obtain identify putative genes involved in biosynthesis pathway of sucrose in sugar beet and comparative transcriptomic analyses in the four developmental stages (50, 90, 160 and 330 days after seedling). As a result of the sugar content analysis, it was increased significantly from 50 to 160 days after seedling (DAS), and then decreased at 330 DAS. On the other hand, the taproot weight, length, and width were increased during all the growth periods. Out of 21,451 genes with expressed value, 21,402 (99.77%) genes had functional descriptions. Among the three comparisons, S1 (50 DAS) vs. S2 (90 DAS), S1 vs. S3 (160 DAS), and S1 vs. S4 (330 DAS), expression profiling of the transcripts was identified 4,991 with differentially expressed genes (DEGs). By comparing the top 20 enriched gene ontology (GO) terms as three comparisons, the top GO terms were commonly confirmed with external encapsulating structure, cell wall, and extracellular regions. In addition, the 38 enriched candidate genes related to sucrose biosynthetic pathway were screened from the entire DEG pool, and the candidate genes might be providing a basic data for further sugar metabolism studies in development of sugar beet taproot.

• The Korean Journal of Physiology
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• v.19 no.1
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• pp.15-23
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• 1985

Previous biochemical studies indicate that $(Na^++K^+)-ATPase$ is composed of two subunits, ${\alpha}$ and ${\beta}$, in a form of ${\alpha}_2{\beta}_2$ with a molecular weight of approximately 300,000 daltons. There is also suggestive evidence that the $Na^+$, $K^+$ pump in human erythrocytes occurs in a complex with some glycolytic enzymes. We assessed here in situ assembly size of the $(Na^++K^+)-ATPase$ of human erythrocytes by applying classical target theory to radiation inactivation data of the ouabain-sensitive sodium flux and ATP hydrolysis of intact cells and ghosts. Cells(in the presence of cryoprotective agent) and ghosts were irradiated at $-45^{\circ}C$ to $-50^{\circ}C$ with an increasing dose of a 1.5 MeV electron beam, and after thawing, the pump and/or enzyme activities were assayed. Each activity measured was decreased as a simple exponential function of radiation dose, from which a radiation sensitive volume (target size) was calculated. When intact cells were used, the target size of both $(Na^++K^+)-ATPase$ and $Na^+$, $K^+$ pump was found to be approximately 600,000 daltons. This target size of the ATPase was reduced to approximately 325,000 daltons if the cells were pretreated with strophanthidin. When ghosts were used, the target size of the ATPase was again approximately 325,000 daltons. Our target size measurement suggests that, in intact cells, the $(Na^++K^+)-ATPase/Na^+,K^+$ pump exists either as a dimer of $(\alpha\beta)_2$ which is a functional unit or as a monomer of $(\alpha\beta)_2$ but in tight complex with other enzyme or enzymes. The results also suggest that this dimeric or heterocomplex association is dissociated during ghost preparation and strophanthidin treatment.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.228-233
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• 2009

This study was conducted to examine the changes in the molecular structure and physiological activities of silk fibroin by gamma irradiation. The results of gel permeation chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the molecular weight of fibroin was increased depending upon the irradiation dose. Secondary structure of fibroin determined by using circular dichroism revealed that the ratio of $\alpha$-helix was increased up to 10 kGy and then decreased depending upon the irradiation dose. Whereas, the ratio of $\beta$-sheet, $\beta$-turn, and random coil were decreased and then increased with an alteration in the $\alpha$-helix secondary conformation. The 2.2-diphenyl-1-picryl-hydrazil (DPPH) radical scavenging activity of fibroin was increased by gamma irradiation at 5 kGy, but was decreased above 10 kGy depending upon the irradiation dose. Also, the inhibition activities of tyrosinase and melanin synthesis of fibroin were increased by gamma irradiation. These results indicated that gamma irradiation could be used as an efficient method to make fibroin more suitable for the development of functional foods and cosmetics.