• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.240-240
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• 2017

Quinoa (Chenopodium quinoa Willd.) is one of the ancient crops cultivated in the Andes region at an altitude of 3,500-4000m in Chile and Bolivia from 5000 BC. It contains a large amount of protein, minerals and vitamins in comparison with other crops. The cultivation area has been increasing worldwide because of its excellent resistance to various abiotic stress such as salinity, drought and low temperature. ${\gamma}$-Ray radiation of high dose is often used as a tool to induce mutations in plant breeding, but it has a deleterious effect on organisms. However, the radiation may have a positive stimulatory effect of 'hormesis' in the low dose range. This experiment was carried out to investigate the optimum dose range for creating the quinoa genetic resources and to investigate the hormesis effect at low dose on the quinoa. This experiment was performed for 120 days from November, 2016 to February, 2017 in the greenhouse of Gyeongsang National University. ${\gamma}$-Ray radiation was irradiated to seeds at 0 Gy, 50 Gy, 100 Gy, 200 Gy, 300 Gy, 400 Gy, 600 Gy, 800 Gy and 1000 Gy for 8 hours. (50 Gy) using the low level radiation facility ($Co^{60}$) of Cooperative Research Institute of Radiation Research Institute, KAERI. Fifty seeds were placed on each petri dish lined with wet filter paper and germination rate was measured at a time interval of 2 hours for 40 hrs. The length of the root length was measured one week after germination. Each treatment was carried out in 3 replicates. The growth of seedlings were investigated for 10 days after transplanting of 30 day-old seedlings. The plant height, NDVI, SPAD, Fv/Fm, and panicle weight were measured. The germination rate was highest at 50Gy and 0Gy and the rate of seeds treated with 400Gy or higher rate decreased to 25% of the seeds treated with 50Gy. The emergence rate of seedling in pot experiment was higher at the dose of 200 Gy, 300 Gy and 400 Gy than at 0 and 50Gy. However, the rate was lower at strong radiation higher than 600Gy at which $1^{st}$ leaf was not expanded fully and dead due to extreme overgrowth at 44 days after treatment (DAT). The highest value of panicle weight was observed at 50Gy (6.15g) and 100Gy (5.57g). On the other hand, the weight at high irradiated dose of 300Gy and 400Gy was decreased by about 55% compared to low dose (50 Gy). NDVI measurement also showed the highest value at 50 Gy as the growth progressed. SPAD was the highest at 400 Gy and showed positive correlation with irradiation dose except 0 Gy. Fv/Fm was high at 50 Gy up to 30 DAT and no difference between treatments was observed except for 400 Gy from 44 DAT. The plant height was the highest in 50Gy during the growing period and was higher in the order of 50Dy, 100Gy, 0Gy, 200Gy, 300Gy and 400Gy in 88 DAT. In this experiment, the optimal radiation dose for hormesis was 50Gy and 100Gy, and the optimal radiation dose for mutagenesis seems to be 400 Gy.

• Animal cells and systems
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• v.14 no.4
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• pp.261-266
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• 2010

PC12 cells were differentiated into the cells of chromaffin phenotype by butyrate treatment. Cells were aggregated and formed tight cell adhesion. To investigate the molecular change in this differentiation, we examined expression levels of cell adhesion proteins and extracellular proteins during butyrate induced-differentiation of PC12 cells. Integrin ${\beta}1$, integrin ${\alpha}7$, E cadherin, VCAM, collagen-I, fibronectin, desmoglein and connexin were increased during differentiation. The levels of clusterin and secreted clusterin were also increased. These increased levels of cell adhesion proteins and extracellular proteins appear to induce cell aggregation and tight cell adhesion. The levels of p21, p27 and p16 were increased probably because of differentiation-related growth arrest during differentiation. Prolonged incubation of butyrate up to 1 day was required for differentiation. Signal transduction pathways for this differentiatiom could not be identified since various inhibitors had no effect. The results showed that butyrateinduced differentiation of PC12 cells to chromaffin cells involves tight cell adhesion and induction of extracellular proteins and cell adhesion proteins.

• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.590-598
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• 2011

Bacterial assimilation of $CO_2$ into stable biomolecules using electrochemical reducing power may be an effective method to reduce atmospheric $CO_2$ without fossil fuel combustion. For the enrichment of the $CO_2$-fixing bacteria using electrochemical reducing power as an energy source, a cylinder-type electrochemical bioreactor with a built-in anode compartment was developed. A graphite felt cathode modified with neutral red (NR-graphite cathode) was used as a solid electron mediator to induce bacterial cells to fix $CO_2$ using electrochemical reducing power. Bacterial $CO_2$ consumption was calculated based on the variation in the ratio of $CO_2$ to $N_2$ in the gas reservoir. $CO_2$ consumed by the bacteria grown in the electrochemical bioreactor (2,000 ml) reached a maximum of approximately 1,500 ml per week. Time-coursed variations in the bacterial community grown with the electrochemical reducing power and $CO_2$ in the mineral-based medium were analyzed via temperature gradient gel electrophoresis (TGGE) of the 16S rDNA variable region. Some of the bacterial community constituents noted at the initial time disappeared completely, but some of them observed as DNA signs at the initial time were clearly enriched in the electrochemical bioreactor during 24 weeks of incubation. Finally, Alcaligenes sp. and Achromobacter sp., which are capable of autotrophically fixing $CO_2$, were enriched to major constituents of the bacterial community in the electrochemical bioreactor.

• Journal of Radiation Protection and Research
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• v.31 no.2
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• pp.91-96
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• 2006

The effects of Magnetic resonance imaging (MRI) on mouse embryos at the early stage of organogenesis were investigated. Pregnant ICR mice were exposed on day 8 of gestation to MRI at 0.5 T for 0.5 hour to 3 hours. The mortality rates of embryos or fetuses, the incidence of external malformations, fetal body weight and sex ratio were observed at day 18 of gestation. A significant increase in embryonic mortality was observed after exposure to either 0.5 T MRI for 0.5 hour or 2 hours. However, the exposure to MRI for 1 hour or 3 hours did not induce any significant increase in embryonic mortality when compared with control. External malformations such as exencephaly, cleft palate and anomalies of tail were observed in all experimental groups exposed to each MRI. A statistically significant increase of external malformations was observed in all groups treated with 0.5 T MRI for 0.5 hour and 3 hours. The incidence of external malformations in the mice group exposed to 0.5 T MRI for 0.5-hour was found to be higher than those of mice group exposed to 0.5 T MRI for 2 hours. The effects of MRI on the external malformations might not to be dose-dependent. There was no statistically significant difference in fetal body weight and sex ratio among each MRI exposure groups.

• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.282-287
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• 2011

Sirt1, a nicotinamide adenine dinucleotide ($NAD^+$)-dependent histone deacetylase, is known to deacetylate a number of proteins that are involved in various cellular pathways such as the stress response, apoptosis and cell growth. Modulation of the stress response by Sirtuin 1 (Sirt1) is achieved by the deacetylation of key proteins in a cellular pathway, and leads to a delay in the onset of cancer or aging. In particular, Sirt1 is known to play an important role in maintaining genomic stability, which may be strongly associated with a protective effect during tumorigenesis and during the onset of aging. In these studies, Sirt1 was generated in stably expressing cells and during the stimulation of DNA damage to examine whether it promotes survival. Sirt1 expressing cells facilitated the repair of DNA damage induced by either ionizing radiation (IR) or bleomycin (BLM) treatment. Fastened damaged DNA repair in Sirt1 expressing cells corresponded to prompt activation of Chk2 and ${\gamma}$-H2AX foci formation and promoted survival. Inhibition of Sirt1 enzymatic activity by a chemical inhibitor, nicotinamide (NIC), delayed DNA damage repair, indicating that promoted DNA damage repair by Sirt1 functions to induce survival when DNA damage occurs.

• Korean Journal of Pharmacognosy
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• v.34 no.2 s.133
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• pp.156-160
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• 2003

$NF-{\kappa}B$ (nuclear factor-kappa B) plays a particularly central role in epidermal biology. It has been established that ultraviolet radiation (UVR) is one of the mechanisms to induce the activation of $NF-{\kappa}B$ in human skin. We previously demonstrated that melanogenic inhibitors may act through the inhibition of $NF-{\kappa}B$ activation in keratinocytes. In order to find another type of melanogenic inhibitors of $NF-{\kappa}B$ activation, various kinds of the extracts from crude drugs $(30\;{\mu}g/ml)$ were preincubated with transfectant HaCaT cells for 3 hrs and then UVR $(60\;mj/cm^2)$ was irradiated. UVR-exposed cells were incubated for another 6 hrs to measure the $NF-{\kappa}B$ activity. $NF-{\kappa}B$ activation was measured with the secreatory alkaline phosphates (SEAP) reporter gene assay using a fluorescence detection method. Among natural products, Lycium chinense, Acanthopanax senticosus, Angelica koreana, Kalopanax pictus and Asparagus cochinchinensis were the most potent inhibitors of $NF-{\kappa}B$ activation by UVR. These observations suggest that some crude drugs might act partially through the modulation of the synthesis of melanotrophic factors to decrease melanogenesis in keratinocytes.

• Radiation Oncology Journal
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• v.13 no.2
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• pp.199-203
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• 1995

Purpose: To evaluate the dose under lung block as a function of depth and the effectiveness of a block as a function of block width. Materials and Methods : Field size of mantle field was $22.8{\times}32.4cm^2.$ Dose distribution of the mantle field was measured with two dimensional water phantom system. To analyze the effectiveness of the lung block. central axis plane, 5cm off-axis plane, and 10cm off-axis plane were studied. Results: The dose under the lung block was recorded with maximum at the depth between 5cm and 10cm. In the central axis plane, dosimetric block width was $10-15\%$ less than physical block width. In the 5cm off-axis plane, dosimetric block width was $4-9\%$ less than physical block width. In the 10cm off-axis plane, dosimetric block width was $2\%$ less than physical block width. Conclusion: Depth dependence of the dose under the lung block was founded. Also, block width dependence of the lung block was founded. To induce the accurate relation between the physical block width and the 'effective' block width, it needs more detailed understanding of the variables involved.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.195-199
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• 1998

To induce the cellulolytic variants of oyster mushroom (Pleurotus ostreatus), basidiospores were irradiated at the dose of $1kGy{\sim}20kGy$ of gamma-ray. After irradiation, activities of extracellular enzymes were determined by the method of MUF residue and genetic similarity was observed by RAPD analysis of variants. Three variants of 2KG-1, 2KG-2 and 20KG-1 were clarified as highly cellulolytic isolates. It seemed that the difference of genetic similarity among variants have derived from gamma-ray radiation. It is suggested that 3 cellulolytic variants induced by gamma-ray in this experiment could play a useful role to reuse cellulosic bioresources.

• Journal of radiological science and technology
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• v.12 no.1
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• pp.3-16
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• 1989

In order to investigate the in vivo effect of $^{60}Co$ radiation on rabbit liver, the uptake ratio and regional excretory value in hepatocytes and Kupffer cells were estimated during acute and chronic hepatic injuries. The left lobe of liver was irradiated at 15 Gy or 30 Gy with a single dose and subsequent changes were analysed with a seial nuclear medicine imaging by using $^{99m}Tc-phytate,\;^{99m}Tc-DISIDA\;and\;^{99m}Tc-HSA$ and resulting data were computerized. The degree of hepatic damage, duration of the injury, and recovery pattern after the irradation were in agreement with the findings of other investigations. However, out values were more quantitative evacuation than those of other publications. Recovery of decreased uptake of $^{99m}Tc-phytate$ was delayed approximately $2{\sim}3$ days later than that of $^{99m}Tc-DISIDA$. In acute radiation induced injury, the results demonstrated that the recovery of Kupffer cells was delayed more than that of hepatocytes. This discrepancy was considered due to the differences in repair activities between these cell types. The decreased of regional excretory value in irradiated area was found to be dose-dependent but had no corelation with regional uptakes of DISIDA and phytate. The decreased of regional excretory value observed in non-irradiated region suggested that irradiated liver might induce an indirect effect.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.51-54
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• 2003

We analyzed radiative properties of aerosols, $CO^{2}$ and clouds using Optical Properties of Aerosols and Clouds(OPAC) and the Column Radiation Model (CRM). From OPAC, if the soot component is disregarded, dust-like components depict the highest extinction values in the solar spectral range and the lowest. single scattering albedoes, which are attributable to the presence of large particles. In the dust aerosol, the high absorptivity in the infrared may induce a warming of the lower atmospheric layer in the nighttime. The radiative properties of aerosols, clouds and double $CO^{2}$ using the CRM model at Seoul (37N, 127.4 E) on 3 April 2003 were calculated. The solar zenith angle is 65˚ and the surface albedo is 0.1836 during the clear day. The aerosol optical depth change 0.14 to 1.7, which is derived during Asian dust days in Korea. At this time, abedo by aerosols is considered as 0.3. In cloudy condition, the short wave cloud forcing on both the TOA and the surface is -193.89 $Wm^{-2}$ and -195.03 $Wm^{-2}$, respectively, and the long wave cloud forcing is 19.58 $Wm^{-2}$ and 62.08 $Wm^{-2}$, respectively. As a result, the net radiative cloud forcing is -174.31 $Wm^{-2}$ and -132.95 $Wm^{-2}$, respectively. We calculate also radiative heating rates by double $CO^{2}$ during the clear day. The $CO^{2}$ volumn mixing ratio is 3.55E-4.