• Title/Summary/Keyword: Ultraviolet radiation

검색결과 410건 처리시간 0.023초

Solar Ultraviolet Irratiance Incident on a Horizontal Surface at Taegu in Korea During 1995-1998 : (II) Ultraviolet-B

  • Suh, Kyehong
    • Journal of Photoscience
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    • 제6권1호
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    • pp.5-6
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    • 1999
  • Solar ultraviolet-B (UV-B) irradiances incident on a horizantal surface at Taegu of Korea during 1995-1998 were calculated with 5 min averges of measuremets taken every 30 seconds by a broadband UV-B sensor. The maximum and minimum of monthly averages of daily UV-B dose were 15.89 KJ m-2 day-1 in April and 3.91KJm-2 day-1 on May 22, 1998 and 1.230W m-2 at 12 : 45, July 13, 1998, respectively. Increasing trend in annual maximum of instantaneous UV-B radiation was averaged to 12.0% per year during 1995-1998 of observation period.

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자외선에 의한 각막의 영향 (The Corneal Effects Induced by Ultraviolet Radiation)

  • 김덕훈
    • 한국안광학회지
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    • 제7권2호
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    • pp.229-234
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    • 2002
  • 인간의 눈과 피부는 태양에너지에 노출이 되어진다. 특히 자외선 노출은 각막 질환에서 중요한 원인으로서 손상이 되어진다. 각막의 이러한 손상은 망막에 영향을 주게된다. 그러므로 눈의 기능은 매우 심각한 영양을 받게 된다. 결과적으로 눈에서 자외선의 보호는 눈 건강에 매우 중요하다. 그러므로 태양에너지네 의한 강한 자외선 환경에 생활하는 인간의 눈은 자외선 차단 선글라스, 안경렌즈, 그리고 콘택트렌즈에 의해서 각막과 안구를 보호하고 있다. 최종적으로 자외선 차단 렌즈 장치는 피검자를 위해 일시적으로 안경사들이 이용할 수가 있다. 물론 앞으로 이런 특수한 렌즈는 연구자들에 의해 개발과 연구가 되어야 한다.

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Galangin (3,5,7-Trihydroxyflavone) Shields Human Keratinocytes from Ultraviolet B-Induced Oxidative Stress

  • Madduma Hewage, Susara Ruwan Kumara;Piao, Mei Jing;Kim, Ki Cheon;Cha, Ji Won;Han, Xia;Choi, Yung Hyun;Chae, Sungwook;Hyun, Jin Won
    • Biomolecules & Therapeutics
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    • 제23권2호
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    • pp.165-173
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    • 2015
  • Most skin damage caused by ultraviolet B (UVB) radiation is owing to the generation of reactive oxygen species. Phytochemicals can act as antioxidants against UVB-induced oxidative stress. This study investigated the protective effects of the flavone galangin against UVB-induced oxidative damage in human keratinocytes. Galangin efficiently scavenged free radicals and reduced UVB-induced damage to cellular macromolecules, such as DNA, lipids, and proteins. Furthermore, galangin rescued cells undergoing apoptosis induced by UVB radiation via recovering mitochondrial polarization and down-regulating apoptotic proteins. These results showed that galangin protects human keratinocytes against UVB radiation-induced cellular damage and apoptosis via its antioxidant effects.

UV램프를 이용한 유수처리형 살균장치의 설계방법 (Design Method for Flowing Water Purification with UV Lamp)

  • 정병균;이진종;정병호
    • 전기학회논문지P
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    • 제58권4호
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    • pp.455-460
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    • 2009
  • A number of factors combine to make ultraviolet radiation a superior means of water purification for ground water, rainwater harvesting systems and so on. Ultraviolet radiation is capable of destroying all types of bacteria. Additionally, ultraviolet radiation disinfects rapidly without the use of heat or chemical additives which may undesirably alter the composition of water. In a typical operation, water enters the inlet of a UV lamp and flows through the annular space between the quartz sleeve and the outside chamber wall. The irradiated water leaves through the outlet nozzle. Several design features are combined to determine the dosage delivered. The first is Wavelength output of the lamp, the Second is Length of the lamp - when the lamp is mounted parallel to the direction of water flow, the exposure time is proportional to the length of the lamp, the third is Design water flow rate - exposure time is inversely related to the linear flow rate, the forth is Diameter of the purification chamber - since the water itself absorbs UV energy, the delivered dosage diminishes logarithmically with the distance from the lamp. In this paper, It describe the how to design optimal UV disinfection device for ground water and rainwater. To search the optimal design method, it was performed computer simulation with 3D-CFD discrete ordinates model and manufactured prototype. Using proposed design method manufactured prototype applied to disinfection test and proved satisfied performance.

자외선에 의한 면역반응의 억제를 회복시키는 면역조절물질을 생산하는 토양 Streptomyces sp.의 분리 및 동정 (Isolation And Identification Of Soil Streptomyces sp. Producing An Immunomodulator That Restores Ultraviolet B Radiation-Induced Suppression Of The Immune Response)

  • 모영근;신영근;박동진;김창진;이종길;한성순
    • 약학회지
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    • 제39권6호
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    • pp.585-592
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    • 1995
  • Soil microorganisms producing immunomoduators that can restore ultraviolet B (UVB) radiation-induced suppression of the immune response were screened in vitro. Exposure of freshly isolated murine epidermal cells (EC) to $180{\;}J/m^{2}$ of UVB radiation resulted in approximately 90% impairtnent of accessory cell function, as measured by their ability to support anti-CD3 monoclonal antibody-induced T-cell mitogenesis. When the culture supenmtants of 150 actinomycete strains were exanuned for their capacity to prevent or repair the UVB-induced impairment of accessory cell function, 4 of them were identified to contain immunomodulators that can restore the decreased accessory cell finiction. The soil isolate that showed the most effective restorative activity, G40025. was selected and fturther characters Addition of 10.mu.l of the culture supernatant of G40025 grown in G-media to cultures of UVB-irradiated EC right after UVB-irradiation restored the decreased accessory cell function by 58%. The immunomodtdator produced by G40025 appeared to be stable at 100.deg. C for 10 min. Taxonomical studies by cultural, morphological, and physiological characterization showed that the soil isolate, G40025, belongs to the genus Streptomyces.

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자외선/적외선 불꽃감지기 소개 및 오동작 방지를 위한 연구 (Introduction of Ultraviolet/Infrared Flame Detector and Method for False Detection Prevention)

  • 임병현;고낙용;황종선;김영민;김종만
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 기술교육전문연구회
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    • pp.8-11
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    • 2003
  • We propose that when combustible burn with contain carbon, introduce fire detector with sensor of private-use detectable light energy as infrared and ultraviolet in energy of electromagnetic-wave type radiate from flame, method for correct discrimination to resemble fire produce false alarm of detector such as sun light, hot object radiation, are welding. This research using infrared sensor is pyroelectric infrared sensor based black body radiation theory. Ultraviolet sensor is uv Tron using gas multiplication effect to current discharge and photoelectric effect of metal. To have high sensibility and to gain proper output voltage, it has high responsive performance. This research introduced UV/IR compound type flame detector and proposed method of false alarm reduced to resemble fire. The result propres the prevention and extinction of fire technique degree, certificated operation of detector.

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전리방사선 및 자외선의 미생물 돌연변이와 DNA 손상에 대한 영향 (Effects of ionizing and ultraviolet radiation on microbial mutation and DNA damage)

  • 남지현;신지혜;이정윤;이동훈
    • 미생물학회지
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    • 제53권1호
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    • pp.20-28
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    • 2017
  • 감마선, 전자빔 등과 같은 전리방사선과 자외선을 이용하는 물리적 멸균방법은 살균 효과와 경제성이 우수하므로 다양한 산업분야에서 사용되고 있으나, 미생물의 돌연변이를 유발하는 요인으로 작용할 수 있다. 본 연구에서는 전리방사선 및 자외선의 유전학적 안전성을 평가하기 위해서 Salmonella enterica와 Escherichia coli 균주에 자외선, 감마선, 전자빔을 조사한 후에 생존율, 돌연변이율, DNA 손상 효과를 조사하였다. 자외선, 감마선, 전자빔의 조사선량이 증가함에 따라 시험 균주의 생존율이 모두 급격히 감소하였으며, 90% 이상이 사멸되는 조사선량은 각각 $0.40{\sim}25.06mJ/cm^3$, 0.11~0.22 kGy, 0.14~0.53 kGy 이었다. SOS/umu-test에서는 자외선, 감마선, 전자빔에 노출된 모든 시료에서 DNA 손상을 유발하는 유전독성이 확인되었다. Ames test에서는 자외선과 감마선에 노출된 후에 복귀 돌연변이율이 각각 $3.82{\times}10^{-4}$, $9.84{\times}10^{-6}$까지 증가하였다. S. enterica TA100의 사멸율이 99.99% 이상 되는 선량의 자외선, 감마선, 전자빔에서의 복귀 돌연변이율은 각각 자연돌연변이율 대비 347배, 220배, 0.6배 증가하였다. E. coli CSH100 균주를 자외선, 감마선, 전자빔에 노출시킨뒤에 조사한 리팜피신내성 돌연변이율은 각각 $2.46{\times}10^{-6}$, $1.66{\times}10^{-6}$, $4.12{\times}10^{-7}$ 이었다. 따라서 사멸효과의 관점에서는 감마선 처리가 미생물 제어에 효과적이라 할 수 있으며, 전자빔은 DNA 손상과 세균돌연변이를 적게 유발하며 사멸효과를 얻는 장점이 있다고 생각된다.

Fucodiphlorethol G Purified from Ecklonia cava Suppresses Ultraviolet B Radiation-Induced Oxidative Stress and Cellular Damage

  • Kim, Ki Cheon;Piao, Mei Jing;Zheng, Jian;Yao, Cheng Wen;Cha, Ji Won;Kumara, Madduma Hewage Susara Ruwan;Han, Xia;Kang, Hee Kyoung;Lee, Nam Ho;Hyun, Jin Won
    • Biomolecules & Therapeutics
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    • 제22권4호
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    • pp.301-307
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    • 2014
  • Fucodiphlorethol G (6'-[2,4-dihydroxy-6-(2,4,6-trihydroxyphenoxy)phenoxy]biphenyl-2,2',4,4',6-pentol) is a compound purified from Ecklonia cava, a brown alga that is widely distributed offshore of Jeju Island. This study investigated the protective effects of fucodiphlorethol G against oxidative damage-mediated apoptosis induced by ultraviolet B (UVB) irradiation. Fucodiphlorethol G attenuated the generation of 2, 2-diphenyl-1-picrylhydrazyl radicals and intracellular reactive oxygen species in response to UVB irradiation. Fucodiphlorethol G suppressed the inhibition of human keratinocyte growth by UVB irradiation. Additionally, the wavelength of light absorbed by fucodiphlorethol G was close to the UVB spectrum. Fucodiphlorethol G reduced UVB radiation-induced 8-isoprostane generation and DNA fragmentation in human keratinocytes. Moreover, fucodiphlorethol G reduced UVB radiation-induced loss of mitochondrial membrane potential, generation of apoptotic cells, and active caspase-9 expression. Taken together, fucodiphlorethol G protected human keratinocytes against UVB radiation-induced cell damage and apoptosis by absorbing UVB radiation and scavenging reactive oxygen species.

자외선 조사 마우스에서 만성 피부손상에 대한 분죽(Phyllostachys nigra var. henenis Strapf)잎 추출물의 효과 (Photoprotective Effect of Bamboo (Phyllostachys nigra var. henenis Strapf) Leaf Extract against Ultraviolet Radiation-induced Chronic Skin Damage in the Hairless Mouse)

  • 변정수;이해준;문창종;김종춘;조성기;장종식;김태환;김성호
    • 방사선산업학회지
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    • 제5권3호
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    • pp.203-210
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    • 2011
  • To evaluate the ability of Bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BL) to protect the skin from photodamage, the gross and microscopic changes in the skin of hairless mice and BL-treated mice exposed chronically to ultraviolet (UV) were examined. The skin of the UV-irradiated mice showed characteristic signs of photoaging, such as deep wrinkles across the back, increased epidermal thickeness, numerous cell infiltration, and many enlarged keratinizing cysts. BL-treated mice showed a significantly decreased wrinkling score and lack of proliferation of cysts. By the 22nd week, 88.9% (i.p. with saline) or 60.0% (topical administration with cream base) of the UV-irradiated mice developed at least one tumor. BL delayed tumor onset significantly. BL (i.p.) was also effective in reducing the occurrence of UV radiation-induced skin tumors and reduced the number of tumors per mouse. After 22 weeks of treatment, 37.5% (i.p.) of the mice treated with BL were tumor-free. Tumor multiplicity was reduced by 81.2% (i.p.) in the BL treated groups. It is noted that skin that is chronically exposed to UV is subject to photoaging and photocarcinogenesis and regular use of BL would prevent these photodamaging effects of UV.