• Title/Summary/Keyword: UV-c

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Dietary effect of red ginseng extracts mixed with torilis fructus and corni fructus on the epidermal levels of ceramides and ceramide related enzyme proteins in uv-induced hairless mice (자외선이 조사된 무모생쥐에서 홍삼, 사상자, 산수유 혼합 추출물 섭취가 표피 세라마이드 함량 및 관련 효소의 발현에 미치는 영향)

  • Lee, Yun-Ju;Oh, Inn-Gyung;Cho, Yun-Hi
    • Journal of Nutrition and Health
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    • v.45 no.3
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    • pp.211-217
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    • 2012
  • UV-irradiation is a major factor of photo-aged skin, by which pigmentation, wrinkles and laxity are increased. In addition, the epidermal barrier is disrupted, ultimately causing dryness in photo-aged skin. As an effort to search dietary sources for improving the dryness of UV irradiated skin, the dietary effect of red ginseng based functional foods on the epidermal level of ceramides, a major lipid maintaining epidermal barrier, was determined in this study. Albino hairless mice were fed either a control diet [group UV (UV-irradiated control)] or diets with 0.5% (group M0.5) or 1% (group M1.0) of red ginseng extracts mixed with Torilis fructus and Corni fructus (66.7% red ginseng) in parallel with UV irradiation for 5 wks. A normal control group (group C) was fed a control diet without UV irradiation for 5 wks. The epidermal level of ceramides in group UV was significantly lower than that in group C, in which ceramidase, an enzyme involved in ceramide degradation, was highly expressed. In group M0.5, the epidermal level of ceramide was significantly increased to the level even higher than in group C. In addition, protein expression of serine palmitoyl transferase (SPT), a key enzyme involved in de novo ceramide synthesis, was increased in group M0.5. However the epidermal levels of ceramides as well as of ceramidase protein expression in group M1.0 did not differ from those in group UV. In conclusion, we demonstrate that dietary supplementation of red-ginseng extracts mixed with Torilis fructus and Corni fructus at a level of 0.5% level in diet increased the epidermal level of ceramides coupled with the elevated expression of SPT protein.

Manufacturing and Characteristics of the Electrodeless UV Lamp for Disinfection of the Sewage Effluent (하수 방류수 살균소독을 위한 무전극 UV 램프의 제조 및 특성)

  • Shin, Dong Ho;Lee, Yong Taek
    • Applied Chemistry for Engineering
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    • v.16 no.4
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    • pp.570-575
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    • 2005
  • In this study, we have manufactured electrodeless ultraviolet lamp which has a long life and a high degree of efficiency than the existing electrode UV lamp used in sewage effluent sterilization disinfection. First, we investigated change of UV intensity and temperature of lamp by activation materials. The best results for the dose response experiments were 250 minutes stabilizing to UV intensity of $300{\mu}W/cm^2$ and surface temperature $200{\sim}250^{\circ}C$ in Hg/Ind's weight ratio 95/5. When electrodeless UV lamp emits light for prolonged hours, surface temperature of lamp increases. therefore, temperature change is studied using a duplex lamp for cooling in actual sewerage process. Also, manufactured electrodeless UV lamp showed sterilization efficiency of more than 99.9% as result that experiment manufactured electrodeless UV lamp by E-coli. for sterilization disinfection of sewage effluent.

Characterization of the UV Oxidation of Raw Natural Rubber Thin Film Using Image and FT-IR Analysis

  • Kim, Ik-Sik;Lee, Bok-Won;Sohn, Kyung-Suk;Yoon, Joohoe;Lee, Jung-Hun
    • Elastomers and Composites
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    • v.51 no.1
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    • pp.1-9
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    • 2016
  • Characterization of the UV oxidation for raw natural rubber (NR) was investigated in controlled conditions through image and FT-IR analysis. The UV oxidation was performed on a thin film of natural rubber coated on a KBr window at 254 nm and room temperature to exclude the thermal oxidation. Before or after exposure to UV light, image of the NR thin film was observed at a right or tilted angle. FT-IR absorption spectra were measured in transmission mode with the UV irradiation time. The UV oxidation of NR was examined by the changes of absorption peaks at 3425, 1717, 1084, 1477, 1377, and $833cm^{-1}$ which were assigned to hydroxyl group (-OH), carbonyl group (-C=O), carbon-oxygen bond (-C-O), methylene group $(-CH_2-)$, methyl group $(-CH_3)$, and cis-methine group $(cis-CCH_3=CH-)$, respectively. During the initial exposure period, the results indicated that the appearance of carbonyl group was directly related to the reduction of cis-methine group containing carbon-carbon double bond (-C=C-). Most of aldehydes or ketones from carbon-carbon double bonds were formed very fast by chain scission. A lot of long wide cracks with one orientation at regular intervals which resulted in consecutive chain scission were observed by image analysis. During all exposure periods, on the other hand, it was considered that the continuous increment of hydroxyl and carbonyl group was closely related to the decrement of methylene and methyl group in the allylic position. Therefore, two possible mechanisms for the UV oxidation of NR were suggested.

UV emission characterization of ZnO thin films depending on the variation of oxygen pressure (분위기 산소압변화에 따른 ZnO박막의 UV발광 특성분석)

  • Bae, Sang-Hyuck;Lee, Sang-Yeol
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1523-1525
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    • 1999
  • ZnO is a wide-bandgap II-VI semiconductor and has a variety of potential application. ZnO exhibits good piezoelectric, photoelectric and optic properties, and is good for a electroluminescence device. ZnO films have been deposited at (0001) shappire by PLD technique. Chamber was evacuated by turbomolecular pump to a base pressure of $1{\times}10^{-6}$ Torr Nd:YAG pulsed laser was operated at ${\lambda}=355nm$. The ZnO films were deposited at oxygen pressures from base to 500 mTorr. The substrate temperatures was increased from $200^{\circ}C$ to $700^{\circ}C$. At aleady works, UV emission and green-yellow PL was observed. In this work, ZnO films showed UV, violet, green and yellow emissions. UV emission was enhanced by increasing partial oxygen pressure. We investigated relationship between partial oxygen pressure and UV emission.

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Study on UV degradation in Polymeric Insulating Materials for Use in Outdoor Insulators by Corona-Charging (코로나 대전을 통한 옥외용 고분자 절연재료의 자외선 열화특성 연구)

  • Youn, Bok-Hee;An, Jong-Sik;Lee, Sang-Yong;Huh, Chang-Su
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.05c
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    • pp.106-109
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    • 2001
  • In this paper, we have investigated the degradation of shed materials of outdoor insulators by UV-radiation by using corona-charging and XPS analysis. The accumulated charges on polymeric surface having intrinsic hydrophobic property have a negative impact on retaining its hydrophobicity. Therefore, shorter decay times of surface charges are preferred. The surface voltage decay on UV-treated silicone rubber and EPDM show a different decay trend with UV treated time. From the XPS analysis, the oxidized groups of silica-like structure in silicone rubber increase with UV treatment time. For EPDM, the oxidized carbon groups of C=O, O=C-O increase as elapse of UV radiation time. These oxidized surface for each material have different electrostatic characteristics, so deposited charges may be expected to have different impacts on their surface hydrophobicity. The degradation mechanism based on our results is discussed.

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Disinfection effects of heat- and cold-treatment and UV-irradiation on campylobacter jejuni (고온 및 저온처리와 자외선조사에 의한 campylobacterjejuni의 살균효과)

  • 김치경;임선희;윤만석;오학식;조민기
    • Korean Journal of Microbiology
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    • v.27 no.3
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    • pp.291-296
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    • 1989
  • Campylobacter jejuni was studied for its disinfection by heat-and cold-treatment and UV-irradiation. When C. jejuni was treated by heat, no viable cell was found after 10 min treatment at $55^{\circ}C$, whereas small fraction of cell population was survived after 60 min treatment at $45^{\circ}C$ and $50^{\circ}C$. When they were treated by cold temperature for 30 days, no cell was survived at -$23^{\circ}C$ but about 4 log of the cells were survived at both temperature of $4^{\circ}C$ and -$40^{\circ}C$. When the organisms were UV-irradiated, thier survival rates were proportionally varied to the distance of irradiation. The scanning electron microscopic studies of C. jejuni cells treated by the disinfecting agents revealed that shapes of thecells were deformed from spiral rod into spherical form. The heat-treated cells showed rough and damaged surface on the scanning electron micrographs. In the heat-treated cells, some proteins of high molecular weight appeared to become accumulated in the electrophoretic analysis. The DNAs extracted from the cells treated with the physical agents showed some differences in agarose gel electrophoresis, comparing those of normal cells.

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Characterization of Excision Repair Genes Related to Damaged DNA Repair from Eukaryotic Cells

  • Choi, In-Soon;Jin, Yong-Hwan;Park, Sang-Dai
    • Environmental Mutagens and Carcinogens
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    • v.17 no.1
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    • pp.1-6
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    • 1997
  • The RAD4 gene of Saccharomyces cerevisiae is essential for the incision step of UV-induced excision repair. A yeast RAD4 gene has been previously isolated by functional complementation. In order to identify the RAD4 homologous gene from fungus Coprinus cinereus, we have constructed cosmid libraries from electrophoretically separated chromosomes of the C. cinereus. The 13 C. cinereus chromosomes were resolved by pulse-field gel electrophoresis, hybridized with S. cerevisiae RAD4 DNA, and then isolated homologous C. cinereus chromosome. The insert DNA of the RAD4 homolog was contained 3.2 kb. Here, we report the partial cloning and characterization of fungus C. cinereus homolog of yeast RAD4 gene. Southern blot analysis confirmed that C. cinereus contains the sequence homologous DNA to RAD4 gene and this gene exists as a single copy in C. cinereus genome. When total RNA isolated from C. cinereus cells was hybridized with the 1.2 kb PvuII DNA fragment of the S. cerevisiae RAD4 gene, a 2.5 kb of transcript was detected. The level of the transcript did not increase upon UV-irradiation, suggesting that the RAD4 homologous gene in C. cinereus is not UV-inducible.

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UV PL property improvements of ZnO nanorods (ZnO 나노로드의 자외선 PL 특성 개선)

  • Ma, Tae Young
    • Journal of IKEEE
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    • v.22 no.3
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    • pp.712-715
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    • 2018
  • ZnO nanorods were grown on ZnO seed films by a hydrothermal method. The rf sputtered ZnO thin films annealed at $600^{\circ}C$ were employed as the seed films. The ZnO nanorods were annealed at $400^{\circ}C$ and $800^{\circ}C$, respectively. The structural and optical property dependence of ZnO nanorods on the annealing was studied. The UV peak showing the strong intensity and narrow FWHM was obtained from ZnO nanorods annealed at $400^{\circ}C$.

Surface Photooxidation of Poly(butylene terephthalate) Films by UV/Ozone Irradiation (자외선/오존 조사에 의한 Poly(butylene terephthalate) 필름의 표면 광산화)

  • Joo, Jin-Woo;Jang, Jinho
    • Textile Coloration and Finishing
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    • v.28 no.2
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    • pp.63-69
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    • 2016
  • Poly(butylene terephthalate)(PBT) surface was modified by UV/ozone irradiation and the effect of UV energy on the surface properties of the irradiated PBT films were characterized by the reflectance, surface roughness, contact angles, ESCA, and ATR analyses of the film surface. The surface reflectance, at the short wavelength of visible spectrum of particularly 400nm, decreased with increasing UV energy. And the irradiation roughened the film surface uniformly in the nano scale. The maximum surface roughness increased from 110nm for the unirradiated sample to 303nm at the UV energy of $10.6J/cm^2$. The surface energy of PBT film increased from $50.5mJ/m^2$ for the unirradiated PBT to $58.8mJ/m^2$ at the irradiation of $21.2J/cm^2$. The improvement in hydrophilicity was caused by the introduction of polar groups containing oxygens such as C-O and C=O bonds resulting in higher $O_{1s}/C_{1s}$. The increased dyeability of the modified film to cationic dyes may be resulted from the photochemically introduced anionic and dipolar dyeing sites on the PBT films surfaces.