• Horticultural Science & Technology
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• v.34 no.4
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• pp.596-606
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• 2016

The growth and contents of anthocyanins and ascorbic acid in lettuce(Lactuca sativa L., 'Jeokchima') as affected by supplemental UV-A LED irradiation under different light quality and photoperiod conditions were analyzed in this study. Five light qualities, namely B (blue LED), R (red LED), BUV (blue LED+UV-A LED), RUV (red LED+UV-A LED) and Control (white fluorescent lamps) with photoperiods of 12/12 hours (day/night), 16/8 hours, or 20/4 hours were provided to investigate the effects of light quality and photoperiod on the growth and accumulation of anthocyanins and ascorbic acid in lettuce leaves. As measured 28 days after transplanting, the number of leaves, leaf length, leaf width, leaf area, shoot fresh weight and dry weight of lettuce were significantly affected by light quality and photoperiod. The number of leaves, leaf length, leaf width, leaf area, shoot fresh weight and dry weight of lettuce grown under R treatment increased with increasing light period. By contrast, leaf development was inhibited, but chlorophyll content increased, under B treatment. Supplemental UV-A irradiation significantly decreased leaf length, leaf width, leaf area and shoot fresh weight. Anthocyanins in lettuce increased significantly with decreasing dark period under B treatment. A synergistic effect of supplemental UV-A LED irradiation on anthocyanins accumulation was found for lettuce leaves grown under R treatment but not B treatment. Ascorbic acid in lettuce was greatly affected by photoperiod. Ascorbic acid content at BUV and RUV treatments increased by 20-30% compared to without UV-A LED irradiation. From these results, it was concluded that growth and contents of anthocyanins and ascorbic acid in lettuce are significantly affected by supplemental UV-A LED irradiation. The results obtained in this study will be informative for efforts to improve the nutritional value of leafy vegetables grown in plant factories.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.177-182
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• 2020

This study evaluated the effect of steam heating, gamma irradiation, and ultraviolet (UV) irradiation on microorganism reduction in order to determine an effective sterilization method for red pepper powder. The effect of each treatment on the reduction of thermoduric bacteria and total aerobic bacteria in red pepper powder were as follows: 10 kGy gamma irradiation, reduction of 4 log and 6 log CFU/g, respectively; 12 mW/㎠ UV irradiation (264 nm UV-C), reduction of less than 1 log CFU/g; steam heating at 120℃ for 40 s, reduction of approximately 2 log CFU/g. High-temperature short-time processing at 110℃ for 30 s reduced the total bacterial count in Gochujang solution from 5.70 log CFU/g to 2.26 log CFU/g; at 121℃, the solution was commercially sterile. Steam heating resulted in 1, 2, and 4 log microbial inactivation in garlic, onion, and pepper powder, respectively. Steam sterilization, which consumers prefer over other methods, may be an effective method for reducing microorganisms in spice powders, including those in red pepper powder.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1204-1210
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• 2014

New control methods are proposed for indoor air quality by removing fine airborne dust-particles. As suspended fine dust-particles contain inorganic dust as well as fine organic bacteria, studies for simultaneous control of these contaminants are required. In this study, photocatalytic disinfection of indoor suspended microorganisms such as E. coli and Bacillus subtilis is performed by three types of photocatalysts with UVA irradiation. The UVA irradiation strength was controlled to the minimum $3{\mu}W/cm^2$, and ZnO, $TiO_2$, and ZnO/Laponite ball were used as the catalysts. The results indicate that E. coli was removed over 80 % after about 2 hours of reaction with UVA and all three types of photocatalysts, whereas only with UVA, around 50 % E. coli removal was obtained. Among the catalysts, ZnO/Laponite composite ball was found to have similar sterilizing capacity to $TiO_2$. However, in case of B. subtilis, which has thick cell wall in its spore state, disinfection was not effective under the low UVA irradiation condition, even with the catalysts. Further studies need to figure out the optimal UVA irradiation ranges as well as photocatalysts doses to control airborne dust, to provide healthy clean air environment.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.429-432
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• 2000

Chitosan scaffold is widely applied to drug delivery and tissue engineering. We have developed chitosan scaffolds, with various pore size, by differing freezing temperature and duration of ultraviolet (UV) irradiation, for reconstructing skin equivalent. Chitosan scaffold was coated with type I collagen, fibronectin and basic fibroblast growth factor (bFGF) in various combinations and concentrations, to evaluate the effect of extracellular matrix (ECM) and bFGF on cell adhesion, growth and differentiation of dermal fibroblasts. Human dermal fibroblasts, isolated from newborn foreskin and passaged between 3 and 5, were seeded on the top of scaffolds and cultivated for 2 weeks. We examined the morphology and the secretion of ECM of fibroblasts using scanning electron microsopy (SEM) and histochemistry. A stellate morphology of fibroblasts were seen in all groups. The scaffold coated with either type I collagen and bFGF or type I collagen and fibronectin, however, showed the best condtion of dermal fibroblasts, in that the highest cell number and ECM secretion were seen. On the contrary, scaffolds coated with all three factors, type I collagen, bFGF and fibronectin, showed lower number of cells and ECM secretion than scaffolds with two factors. There was a tendency of dose-dependence in all three factors for fibroblast growth and ECM secretion. In conclusion, we may suggest that chitosan scaffold coated with either type I collagen/bFGF or type I collagen/fibronectin could provide more favorable environment for the growth and differentiation of dermal fibroblasts.

• Applied Chemistry for Engineering
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• v.23 no.5
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• pp.496-500
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• 2012

Arthrospira platensis (A. platensis) is an economically important filamentous microalgae. The isolation of mutants by chemical or physical mutagen is a clue for the strain improvement. In this study, effects of ultraviolet-B (UV-B) radiation on A. platensis were investigated. Cells (or microalgae) were exposed to UV-B (15 Watt, 254 nm) for 1, 3, 5, and 10 min, and resulting mutants were designated UM1, UM3, UM5, and UM10, respectively. Especially, the lipid content of UM5 mutant was considerably increased by 8~11 fold compared to that of wild types. Moreover, the carotenoid content and antioxidant enzyme (peroxidase and superoxide dismutase) activity were increased. It was shown that UV-induced mutants can accumulate bioactive compounds, which will be useful for the industrial production of valuable products.

• Elastomers and Composites
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• v.36 no.3
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• pp.195-200
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• 2001

Ultraviolet photografting of acrylic acid onto low density polyethylene was characterized using XPS and contact angle measurement. Effects of surface modification at LDPE and aluminum on LDPE/Al laminate were also investigated. Contact angle decreased significantly at initial state arid tends to level off with increasing UV irradiation time. The improvement of hydrophilicity was due to the presence of acrylic acid on LDPE surface. Graft of acrylic acid onto LDPE was also identified from O1s/C1s ratios in XPS spectrum. Adhesion strength of LDPE-g-AAc/Al laminate showed about 30 times higher than LDPE/A1 system and it could be attributed to the increase of polarity of LDPE surface. Chemical treatment of Al surface using sulfuric acid/sodium dichromate also increased the adhesion strength of LDPE/Al laminate. Adhesion strength of LDPE/Al laminate decreased significantly under acetic acid.

• Journal of the Korean Applied Science and Technology
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• v.38 no.5
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• pp.1249-1254
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• 2021

UV induce oxidative stress and increase matrix metalloproteinase (MMP) expression, resulting in skin aging. Thus, preventing skin damage from ultraviolet B (UVB)-induced skin damage can attenuate skin aging. Spirulina is comprised of prokaryotes a powerful antioxidant. This study aimed to investigate the photoprotective effects of spirulina-derived phycocyanin (PC) against UVB radiation using human skin fibroblast. As a results, PC showed no toxicity at concentrations of 5-40 ㎍/mL in terms of fibroblast viability. Survival rate of UVB-irradiated fibroblast incresased to 73.5% from 50.5% with PC treatment. UVB treatment increased MMP-1 and MMP-9 expression whereas PC treatment decreased it. The results indicate that PC might reduce or prevent skin aging by reducing UVB irradiation-induced skin wrinkles and free radicals.

• Journal of Life Science
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• v.20 no.11
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• pp.1603-1610
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• 2010

Fucoidans are sulfated fucosylated polymers from the cell wall of brown algae. We assessed the effects of Fucus evanescens fucoidan on ultraviolet-B (UVB)-induced expression of matrix metalloproteinase-1 (MMP-1) protein, mRNA, and promoter, and the phosphorylation of mitogen-activated protein kinases in vitro using an immortalized human keratinocyte cell line. Pretreatment with 10 and $100\;{\mu}g/ml$ fucoidan significantly inhibited UVB-induced MMP-1 protein, mRNA and promoter activity, compared to UVB irradiation alone. Extracellular signal regulated kinase activation was markedly inhibited by treatment with fucoidan, though c-JUN N-terminal kinase activity and p38 activation were only marginally affected by fucoidan. F. evanescens fucoidan may be a potential therapeutic agent for the prevention and treatment of skin photoaging.

• The Korean Journal of Community Living Science
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• v.18 no.1
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• pp.55-62
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• 2007

The purpose of this study was to determine the usefulness of Shiitake mushroom, which was rich in vitamin $D_2$ through UV irradiation. For the practical use, we prepared the cold buckwheat noodles using UV irradiated Shiitake mushroom powder and seaweed derived calcium. The time required to acquire $2.5 J/cm^2$ of UV was 30-45 minutes, when the mushrooms were disposed 18 cm below within 1 cm from the UV light. Among the texture profiles detected by texture analyzer, adhesiveness and chewiness were significantly influenced by addition of mushroom powder and/or calcium. Adhesiveness appeared in only 3% mushroom powder noodle, and chewiness was significantly decreased by both of mushroom powder and seaweed calcium. Shiitake powder lowered lightness(L) and yellowness(b), but these deminishing effect on L and B value were compensated with addition of seaweed clacium. With cooking, the value of L was increased and redness(a) and yellowness(b) were decreased in comparison with raw noodle. According to sensory evaluation, addition of Shiitake and calcium increased the preference scores of color and overall acceptance of cold buckwheat noodles, but flavor, taste and texture were not influenced by those ingredients. We concluded that addition of 5% Shiitake and/or calcium to cold buckwheat noodles might give advantages for born health without bad effects on characteristics of those noodles.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.2
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• pp.183-188
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• 2013

Ultraviolet (UV) B irradiation induces the production of matrix metalloproteinases (MMPs), which are responsible for the degradation or synthesis inhibition of collagenous extracellular matrix in connective tissues, causing skin photoaging. In this study, we examined the inhibitory effect of MMP-1 expression of yam extract in tumor necrosis factor-alpha (TNF-${\alpha}$)-stimulated human dermal fibroblast neonatal (HDFn) cell and preventive effect of UVB-induced damage in hairless mice skin. The synthesis of procollagen and the release of MMP-1 in HDFn cells were measured by EIA kit and MMP-1 assay kit, respectively. UVB radiation was applied to the backs of the mice three times a week for 8 weeks. Mice were randomly divided into three groups, and were topical application with the Dioscorea batatas (DB, 6%) or vehicle. Reduction of TNF-${\alpha}$-induced procollagen synthesis was increased by DB (50 ug/ml), which was higher than positive control group (TGF-${\beta}$). Also, pre-treatment of HDFn cells with DB inhibited TNF-${\alpha}$-induced release of MMP-1. In vivo study, we found that preventive effect of DB against UV-induced epidermal thickness. DB suppressed the expression of MMP-3 and MMP-13 induced by UVB irradiation. Our results show that DB have preventive effect of UV-induced skin damage in hairless mice.