• Title/Summary/Keyword: minimal erythemal dose

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Characteristics of Erythemal Ultraviolet Irradiance operating at Korea Meteorological Administration (기상청에서 운용 중인 지역별 지표 홍반자외선(EUV-B) 복사의 특성)

  • Hong Gi-Man;Choi Byoung-Cheol
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.2
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    • pp.223-233
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    • 2006
  • We analyzed the monthly and seasonal mean of the daily Erythemal Ultraviolet-B (EUV-B, $280{\sim}320nm$) irradiance operating in Pohang, Anmyeon, Gosan, Mokpo and Kangnung with UV-Biometer (Solar Light Co., Model No. 501) at clear-sky noon during the period from 1999 to 2004. Also, we investigated the seasonal and regional characteristics for the UV index over the Korean Peninsula. The daily maximum occurred near solar southing time and the highest monthly accumulated EUV-B irradiance appeared in July and August at each regional observatory. The monthly mean value of the clear-sky EUV-B irradiance in Pohang, Anmyeon, Gosan, Mokpo and Kangnung showed 196.6, 161.8, 221.9, $171.5mWm^{-2}\;and\;179.7mWm^{-2}$ near noon in July respectively. The annual mean value of the daily accumulated EUV-B irradiance in Pohang, Anmyeon, Gosan, Mokpo and Kangnung were 1.8, 2.1, 2.2, $1.8kJm^{-2}\;and\;1.5kJm^{-2}$ respectively. The UV Index (UVI) showed above UVI 7(High) more than 90 days during one year over the Korean Peninsula.

Inhibitory Effect of PME88 MelonSOD on the Ultraviolet-Induced Photo-aging (PME88 멜론SOD의 자외선으로 인한 피부 광노화 억제 효과)

  • Cho, Se-Haeng
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.4
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    • pp.401-408
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    • 2009
  • PME88 (gliadin-combined) melon superoxide dismutase (SOD) is known to promote the production of the body‘s own natural antioxidants including superoxide dismutase, catalase and glutathione peroxidase. In this study, we investigated the inhibitory effects of PME88 melonSOD on the ultraviolet-induced photo-aging by the evolution of minimal erythemal dose (MED), erythema quotation and spectrocolorimetric measurements of erythema. The analysis of the evolution of the MED showed a significant increase 28 days after the daily taken of the PME88 melonSOD. The analysis of the erythema quotation showed that on D29, for the dose 1.25 MED, erythema intensity is significantly higher for placebo group than for PME88 melonSOD group. At doses 0.64 MED$_{D14}$, 0.80 MED$_{D14}$ and 1 MED$_{D14}$ the value of parameter $a^*$ (the most sensitive to the colour changes bound to the variations of blood flow. It permits to assess the evolution of erythema) is significantly higher for placebo group. No significant difference has been observed between groups (PME88 melonSOD and placebo) on the evolution of the number and consistency of feces after 4 weeks of treatment. No intolerance has been observed during the 4 weeks of treatment. These results mean that PME88 melonSOD as a dietary supplement could be useful to attenuate ultraviolet-induced skin photo-aging.

The Radiative Characteristics of EUV-B over the Korean Peninsula and Exposure Time for Synthesizing Adequate Vitamin D (한반도 EUV-B 복사의 특성분석 및 적정 비타민D 합성을 위한 노출시간 산출)

  • Kwak, Min Kyoung;Kim, Jae Hwan
    • Atmosphere
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    • v.21 no.1
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    • pp.123-130
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    • 2011
  • In this study, we have analyzed the radiative characteristics of erythemal ultraviolet-B (EUV-B from 1999 to 2005) over the Korean Peninsula. EUV-B measured at Gangneung, Anmyondo, Mokpo, and Gosan represents the measurements from clean areas and that at Seoul represents from a polluted area. The magnitudes of EUV-B increase in proportion to the latitudinal decrease. Monthly mean variation of EUV-B at noon shows the maximum value of $158.5mWm^{-2}$ in August and the minimum value of $36.4mWm^{-2}$ in December in the clean areas. Seasonal mean diurnal variation of EUV-B shows a peak around noon (12:00 ~ 13:00 hr) and its intensity varies along with a season in order of summer > spring > fall > winter. The maximum value of $56.4mWm^{-2}$ in summer is three times higher than that in winter ($14.3mWm^{-2}$). The value of EUV-B in the polluted area is lower than that in the clean areas, resulting from the effects of the blocking, reflection, and scattering of EUV-B due to high concentrations of PM10. UV-B is an essential element to synthesize vitamin D in human body. 200 IU(International Unite) of vitamin D can be formed by an exposure of 6-10% of body surface area to 0.5 MED(Minimal Erythemal Dose). In order to form vitamin D, the calculated exposure times to EUV-B are 15 min. in spring, 12 min. in summer, 18 min. in fall, and 37 min. in winter for the clean areas and 16, 16, 24, and 37 min. for the polluted area.

Characteristic of MED measurement Value of Trial Subjects from Ultraviolet Irradiation (자외선 조사 피험자의 MED 측정 값의 특성에 관한 연구)

  • Suk, Jang Mi;Park, Shin Young;Choi, Mi Ra;An, Song Yi;Kim, In Soo;Kim, Beom Joon;Park, Jin O;Jung, Sang Wook
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.3
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    • pp.251-257
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    • 2013
  • In this study, ultraviolet protection factor (Sun Protection Factor, SPF) was investigated to provide basic data for subject safety and research of ultraviolet (UV) irradiation test in the future. Trial subjects (395 people) of skin type I, II, and III were evaluated according to skin type standard table. After measuring the skin color using a colorimeter, ITA (Individual Typology Angle) value was calculated. Subjects with 28 and above ITA value were positioned comfortably to be UV irradiated for 60 s and erythema was evaluated 24 hours after application. MED (Minimal Erythema Dose) was investigated where the minimal amount of erythema existed among UVB irradiated area. Statistical analysis was investigated using Statistical Package the Social Sciences program. As a result, the darker skin color results in the higher MED value since the higher skin type number results increased MED value and female has higher MED value than male since female has darker skin type than male. There was no relation between MED difference by ages in all different ages. However, it is hard to draw a conclusion as above since the number of subjects were not sufficient to support statistical significance for MED values by different ages. However, MED values by skin types obtained through this study can be used as a standard when MED value is expected to evaluate efficacy of sunscreen product and as basic data for further safety of clinical researches.