• Nutrition Research and Practice
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• v.17 no.4
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• pp.641-659
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• 2023

BACKGROUND/OBJECTIVES: The skin is the outermost organ of the human body and plays a protective role against external environmental damages, such as sunlight and pollution, which affect anti-oxidant defenses and skin inflammation, resulting in erythema or skin reddening, immunosuppression, and epidermal DNA damage. MATERIALS/METHODS: The present study aimed to investigate the potential protective effects of red orange complex H extract (ROC) against ultraviolet (UV)-induced skin photoaging in Skh:HR-2 mice. ROC was orally administered at doses of 20, 40, and 80 mg/kg/day for 13 weeks, along with UV irradiation of the mice for 10 weeks. RESULTS: ROC improved UV-induced skin barrier parameters, including erythema, melanin production, transepidermal water loss, elasticity, and wrinkle formation. Notably, ROC inhibited the mRNA expression of pro-inflammatory cytokines (interleukin 6 and tumor necrosis factor α) and melanogenesis. In addition, ROC recovered the UV-induced decrease in the hyaluronic acid and collagen levels by enhancing genes expression. Furthermore, ROC significantly downregulated the protein and mRNA expression of matrix metalloproteinases responsible for collagen degradation. These protective effects of ROC against photoaging are associated with the suppression of UV-induced phosphorylation of c-Jun NH2-terminal kinase and activator protein 1 activation. CONCLUSIONS: Altogether, our findings suggest that the oral administration of ROC exerts potential protective activities against photoaging in UV-irradiated hairless mice.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.1
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• pp.50-57
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• 2011

This study examined the effect of gamma irradiation (3-20 kGy) on the immune activity and physicochemical properties of Myagropsis myagroides (MM) water extracts. MM powder and water extracts were subjected to gamma irradiation at 3, 7, and 20 kGy. The effects of gamma-irradiated MM water extracts on splenocyte proliferation and cytokine IFN-${\gamma}$ and IL-2 secretion were evaluated. The gamma-irradiated MM water extracts resulted in decreased splenocyte proliferation without cytotoxicity. The IFN-${\gamma}$ and IL-2 secretion increased by gamma-irradiated MM water extracts with increasing irradiation dose. For MM powder, the yield and total phenolic compounds (TPC) of water extracts were increased slightly after gamma irradiation. In MM water extracts, the TPC was higher at a dose of 20 kGy, while gamma irradiation decreased the viscosity, pH, and color of the MM extracts. In conclusion, gamma irradiation improved the immunomodulatory activity of MM water extracts, overcoming its potential weakness when applied in the food industry.

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.507-513
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• 2012

This research was performed to evaluate the superparamagnetic iron oxide nanoparticles'(SPIONs) cell toxicity and to measure the radiation cell survival curve changes of SPIONs-uptake glioblastoma multiforme cells. The results could be practically used as the fundamental data to ameliorate proton beam cancer therapy, for example, providing necessary GBM treatment dose in the proton beam therapy when the therapy takes advantage of SPIONs. The assessment of the toxicological evaluation of synthesized SPIONs was accomplished by MTT assay as an in vitro experiment. The results showed no meaningful differences in the cell survival rate at the $1-100{\mu}g/ml$ SPIONs concentrations, but the cell toxicity was shown as the cell survival rate decreased up to 74.2% at the $200{\mu}g/ml$ SPIONs concentration. Then, we measured each radiation cell survival curve for U373MG cells and SPIONs-uptake U373MG cells with 0~5 Gy of proton beam irradiations. It is learned from the analysis of the experimental results that the SPION-uptake cells' radiation survival rate was more rapidly decreased as the irradiation dose increased. In conclusion we confirmed that SPIONs-uptake in U373MG cells induces cell death at the much less dose than the lethal dose of SPION-non-uptake cell. This research shows that the therapeutic efficacy of glioblastoma multiforme treatment in proton beam therapy can be improved by SPIONs targeting to the GBM cells.

• Journal of Radiation Protection and Research
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• v.41 no.3
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• pp.268-273
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• 2016

Background: This study was a long-term evaluation of $^{137}Cs$ and $^{90}Sr$ activity concentrations in seawater samples from the East Sea, Korea, in order to establish current activity levels. Results and long-term monitoring trends will be useful in the future monitoring of environmental radioactivity. Materials and Methods: Surface seawater samples were collected quarterly from Guryongpo and Jangho in the East Coast between 1998 and 2010 and the quarterly deep seawater samples were collected from three sites in the sea adjacent to Ulleung-do between 2012 and 2015. The activity concentrations of $^{137}Cs$ were measured using a gamma-spectrometer. The activity concentrations of $^{90}Sr$ and $^{90}Y$ in a radioactive equilibrium state were measured using a gas flow proportional counter. Results and Discussion: We found the annual average activity concentrations of $^{137}Cs$ in the surface seawater was $1.66-2.89mBq{\cdot}kg^{-1}$ in Guryongpo and $1.68-2.43mBq{\cdot}kg^{-1}$ in Jangho. The annual average activity concentrations of $^{90}Sr$ in the surface seawater was $0.83-1.98mBq{\cdot}kg^{-1}$ in Guryongpo and $0.82-1.57mBq{\cdot}kg^{-1}$ in Jangho. The annual average activity concentrations of $^{137}Cs$ in the deep seawater sites were $1.51-1.73mBq{\cdot}kg^{-1}$, $1.19-1.60mBq{\cdot}kg^{-1}$ and $0.87-1.15mBq{\cdot}kg^{-1}$ in TH, JD, and HP. The annual average activity concentrations of $^{90}Sr$ in the same deep seawater sites were $1.00-1.94mBq{\cdot}kg^{-1}$, $0.82-1.26mBq{\cdot}kg^{-1}$, and $0.79-1.32mBq{\cdot}kg^{-1}$. The effective half-life was calculated by analyzing change over time in the activity concentration in the surface seawater. The effective half-life of $^{137}Cs$ was $15.3{\pm}0.1years$ in Guryongpo and $102{\pm}3years$ in Jangho. The effective half-life of $^{90}Sr$ was $28.3{\pm}4.3years$ in Guryongpo and $16.6{\pm}0.1years$ in Jangho. The ratio of the average activity concentration ($^{137}Cs/^{90}Sr$) was 1.72 in the surface seawater, which is similar to the reported ratio of the global radioactive fallout. The ratio in the deep seawater was 1.24, which is somewhat low compared to the global ratio (1.6, 1.8). Conclusion: Activity concentrations of $^{137}Cs$ and $^{90}Sr$ in the seawaters of the East Sea were similar to the previously reported activity levels in the East Sea and northwestern Pacific as a result of global radioactive fallout following atmospheric nuclear weapon tests.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.909-917
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• 2018

3D printing technology is expected to be an innovative technology of the manufacturing industry during the 4th industrial revolution, and it is being used in various fields including biotechnology and medical field. In this study, we verified the printing materials through Monte Carlo simulation to evaluate the radiation shielding ability of the raw material using this 3D printing technology. In this paper, the printing materials were selected from the raw materials available in a general-purpose FDM-based 3D printer. Simulation of the ICRU phantom and the shielding system was carried out to evaluate the shielding effect by evaluating the particle fluence according to the type and energy of radiation. As a result, the shielding effect tended to decrease gradually with increasing energy in the case of photon beam, and the shielding effect of TPU, PLA, PVA, Nylon and ABS gradually decreased in order of materials. In the case of the neutron beam, the neutron intensity increases at a low thickness of 5 ~ 10 mm. However, the effective shielding effect is shown above a certain thickness. The shielding effect of printing material is gradually increased in the order of Nylon, PVA, ABS, PLA and TPU Respectively.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.3
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• pp.226-236
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• 2021

Objectives: Concerns have been raised about the possible health effects of radon on both workers and consumers with the spread of social attention to the impact of radon exposure. Thus, an entire raw material handling workshop was investigated, and standards for radon levels in the workplace were newly established at 600 Bq/m³. However, regulations on the management of workers exposed to radon are still insufficiently developed. Therefore, by comparative analysis of overseas and domestic radon-related regulations for workplaces, this study aims to suggest improvement plans of protection regulations under the Occupational Safety and Health Act (OSH Act) for the prevention of health disorders of radon-exposed workers. Methods: For overseas case studies, we consulted radon-related laws and reports officially published on the websites of the European Union (EU), the United States (U.S.) and the United Kingdom (UK) government agencies. Domestic law studies were conducted mainly on the Act on Protective Action Guidelines against Radiation in the Natural Environment and the OSH Act. Results: In Europe, the basic safety standards for protection against risks arising from radon (Council Directive 2013/59/EURATOM of 5 December 2013) was established by the EU. They recommend that the Member States manage radon level in workplaces based on this criterion. In the U.S., the standards for workplaces are controlled by the Occupational Safety and Health Administration (OSHA) and the Mine Safety and Health Administration (MSHA). Action on radon in the UK is specified in "Radon in the workplace" published by the Health and Safety Executive (HSE). Conclusions: The Act on Protective Action Guidelines against Radiation in the Natural Environment mainly refers to the management of workplaces that use or handle raw materials but does not have any provisions in terms of protecting naturally exposed workers. In the OSH Act, it is necessary to define whether radon is included in radiation for that reason that its current regulations have limitations in ensuring the safety workers who may be exposed to naturally occurring radon. The management standards are needed for workplaces that do not directly deal with radon but are likely to be exposed to radon. We propose that this could be specified in the regulations for the prevention of health damage caused by radiation, not in Article 125 of the OSH Act.

• Korean Journal of Microbiology
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• v.53 no.1
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• pp.20-28
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• 2017

Physical sterilization methods using ultraviolet radiation and ionizing radiation such as gamma ray and electron beam are applied in various industry fields due to disinfection effects and economic efficiency but may also cause microbial mutation. In this research, Salmonella enterica and Escherichia coli strains were treated with ionizing and ultraviolet radiation and their survival rate, mutation rate, and DNA damage were studied to evaluate the genetic safety. The survival rate of the strains decreased drastically as the irradiation dose of ultraviolet ray, gamma ray, and electron beam increased, and over 90% of the strain was exterminated at a dosage of $0.40{\sim}25.06mJ/cm^3$, 0.11~0.22 kGy, 0.14~0.53 kGy respectively. In SOS / umu-test, genotoxicity causing DNA damage was identified in all samples. In Ames test, back-mutation rate increased to $3.82{\times}10^{-4}$ and $9.84{\times}10^{-6}$ respectively when exposed to ultraviolet ray and gamma ray. At exposure to ultraviolet ray, gamma ray, and electron beam with dosage of over 99.99% extinction rate of S. enterica TA100, back-mutation rate increased 347 times, 220 times, 0.6 times respectively to the spontaneous back-mutation rate. Rifampicin resistance mutation rate of E. coli CSH100 exposed to ultraviolet ray, gamma ray, and electron beam was $2.46{\times}10^{-6}$, $1.66{\times}10^{-6}$, $4.12{\times}10^{-7}$ respectively. Therefore, gamma radiation is effective in microorganism control from the perspective of disinfection and electron beam has the advantage of sterilizing with little DNA damage and bacterial mutation.

• Journal of Plant Biotechnology
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• v.45 no.2
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• pp.140-145
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• 2018

Inducing genetic and morphological variation through conventional method is very difficult. Therefore, mutation induction through in vitro technology brings numerous advantages over the conventional breeding. Thus, the individual shoots (1 ~ 2 cm) were irradiated with gamma rays (10 ~ 70 Gy). The result revealed that the explants treated with higher doses (40, 50, 60, and 70 Gy) showed deleterious effects of ionizing radiation. The highest survival rate among ${\gamma}$ treated explants recorded was 71% in 10 Gy treatments while the lowest survivality was 15% in 70 Gy. Lethal dose 50% ($LD_{50}$) dose was found to be 33 Gy. In the in vitro condition, rooting reponse showed that increase in gamma irradiation dose resulted in the inhibition of root growth. Meanwhile, non-treated explants had the best rooting ability with the maximum number of root per explant (20) within a short period of time (6 days), with the highest root length of (15.1 cm). The longer period in rooting (12 days) and lowest number of root per explant (8) with shortest root length (10.1 cm) were recorded at 30 Gy treatment. The highest shoot length (13.6 cm) was observed at control treatment and the shortest shoot length (10.4 cm) was observed at 30 Gy. In the nursery, lowest leaf number (5) was observed at 30 Gy compared with other treatments. The highest chlorophyll content (49.8) was recorded at 10 Gy treated seedling. Irradiated explants with 10 Gy found to be superior over the control treatment and had positive effects in main growth parameters such as chlorophyll content.

• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.215-220
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• 2007

One of the important functions of skin is protection from harmful environments. Many studies have explored how to prevent skin from wrinkling and the occurrence of pigmentation changes. Skin wrinkling and pigmentation changes could be caused by unusual disruption of connective tissue, the formation of free radicals and ultraviolet radiation. In this study, extracts obtained from 254 different kinds of Jeju medicinal plants were screened for inhibitory effects on tyrosinase and elastase, and for free radical scavenging effects. Four herbs, Phormium tenax, Morus bombycis, Morus alba, and Cudrania tricuspidata, were potent inhibitors of tyrosinase ($IC_{50}$ values 4.62, 5.46, 8.17, and 64.17 ${\mu}g$/mL, respectively). Aleurites fordii [$IC_{50}$: 5.29 ${\mu}g$/mL, 1,1-diphenyl-2-picrylhydrazyl (DPPH)], Distylium racemosum ($IC_{50}$: 6.14 ${\mu}g$/mL), Acer palmatum ($IC_{50}$: 5.44 ${\mu}g$/mL), and Spiraea salicifolia ($IC_{50}$: 5.25 ${\mu}g$/mL) showed good antioxidative effects. Furthermore, Distylium racemosum ($IC_{50}$: 7.51 ${\mu}g$/mL), Diospyros kaki ($IC_{50}$: 15.1 ${\mu}g$/mL), Cornus macrophylla ($IC_{50}:$ 16.59 ${\mu}g$/mL), and Psidium guajava ($IC_{50}$: 40.25 ${\mu}g$/mL) exhibited potent inhibitory effects on elastase. These results suggest that medicinal plants possessing several biological activities may be potent inhibitors of the processes involved in pigmentation increases and aging. Further investigations will focus on in vivo assays and on the chemical identification of the major active components responsible for whitening and anti-aging activity in the screened efficacious extracts.

• The Plant Pathology Journal
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• v.31 no.4
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• pp.343-349
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• 2015

Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) is one of the most important bacterial diseases of citrus. Because citrus canker is not found in many countries including European Union and Australia, Xcc is strictly regulated in order to prevent its spread. In this study, the effects of X-irradiation on Xcc growth either in the suspension or on the surface of citrus fruits were investigated. The suspension containing $1{\times}10^7cfu/ml$ of Xcc was irradiated with different absorbed doses of X-irradiation ranging from 50 to 400 Gy. The results showed that Xcc was fully dead at 400 Gy of X-irradiation. To determine the effect of X-irradiation on quarantine, the Xcc-inoculated citrus fruits were irradiated with different X-ray doses at which Xcc was completely inhibited by an irradiation dose of 250 Gy. The $D_{10}$ value for Xcc on citrus fruits was found to be 97 Gy, indicating the possibility of direct application on citrus quarantine without any side sterilizer. Beside, presence of Xcc on the surface of asymptomatic citrus fruits obtained from citrus canker-infected orchards was noted. It indicated that the exporting citrus fruits need any treatment so that Xcc on the citrus fruits should be completely eliminated. Based on these results, ionizing radiation can be considered as an alternative method of eradicating Xcc for export of citrus fruits.