• Title/Summary/Keyword: ultraviolet B

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Ultraviolet A Induces Immunosuppression, Protection or Memory Enhancement Depending on Dose, while Ultraviolet B is Immunosuppressive and Tolerogenic over a Large Dose Range

  • Halliday, Gary M.;Byrne, Scott N.
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.197-200
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    • 2002
  • UVR-induced immunosuppression contributes to skin cancer. The aim was to construct accurate dose response curves for primary and secondary contact sensitivity for solar-simulated UVR (ssUVR; 290-400nm), UVA and UVB as the role of UVA in immunosuppression is controversial. We used a xenon arc source. The mice were immobilised, enabling accurate dosing. C57BL/6 mice were immunosuppressed at half the dose of ssUVR required to cause sunburn but not by higher doses (up to the sunburn dose). Thus, ssUVR causes systemic immunosuppression only over a narrow, low dose range. UVA caused suppression at low but not high doses whereas UVB induced immunosuppression at all doses tested. 8 weeks later the mice were resensitised to assess tolerance. Mice exposed to the minimum immunosuppressive dose of ssUVR prior to primary sensitisation were tolerant to re-sensitisation. However, at higher doses of ssUVR, these mice were protected from tolerance. Interestingly, while low doses of UV A caused immunosuppression, even lower doses enhanced the response to the second sensitisation. Higher doses of UVA had no affect. UVB induced tolerance in a dose related manner. Thus, ssUVR only induces immunosuppression and tolerance over a narrow dose range. Both UVA and UVB are immunosuppressive at this dose, while higher doses of UVA protect from the suppressive effects of UVB. Surprisingly very low doses of UVA enhanced memory development. Thus UVR has complex effects on the immune system depending on dose and spectrum.

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Ultraviolet Spectrophotometry of VV Cephei

  • Kang, Young-Woon
    • Bulletin of the Korean Space Science Society
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    • 1992.10a
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    • pp.14-14
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    • 1992
  • The IUE archival spectra of VV Cephei were collected to investigate the eclipse nature in the ultraviolet. The temperature of the B star has been determined, as approximately30,OOOK, based en the flux distributions durstributions during egress, Light curves of VV Cephei were reduced from the spectrophotometry of the IUE archival spectra. Three light curves at the center wavelengths of 2350A,2550A and :!850A have been analyzed by the modified Wilson and Oevinney light curve program. the radii of the B star and M star were deduced to 0.05 and 0.22 of uint separation, respectively. The UV light curves show anevidence that the light was attenuated by the highly opaque atmosphere of the M star

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Effects of Aucubin Isolated from Eucommia ulmoides on UVB-induced Oxidative Stress in Human Keratinocytes HaCaT

  • Ho, Jin-Nyoung;Cho, Hong-Yon;Lim, Eun-Jeong;Kim, Hye-Kyung
    • Food Science and Biotechnology
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    • v.18 no.2
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    • pp.475-480
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    • 2009
  • Ultraviolet B (UVB) radiation provokes the generation of reactive oxygen species (ROS) in the cells and skin, which induce oxidative stress in the exposed cells, leading to photoaging and cancer. Using the human keratinocytes HaCaT cell line, we investigated the photoprotective effects of aucubin isolated from Eucommia ulmoides. Pretreatment with aucubin markedly suppressed UVB-induced oxidative stress, which manifests as a decrease in intracellular lipid peroxidation, elevation of catalase activity, and reduced glutathione content. In addition, aucubin significantly reduced expression of matrix metalloproteinase-1 (MMP-1) protein (54%) and mRNA. Taken together, these results suggest that aucubin may offer protection against UVB-induced oxidative stress and may be used as a potential agent in prevention of UVB-induced photoaging.

ULTRAVIOLET SPECTROPHOTOMETRY OF VV CEPHEI

  • Kang, Young-Woon
    • Journal of Astronomy and Space Sciences
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    • v.9 no.1
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    • pp.111-119
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    • 1992
  • The IUE archival spectra of VV Cephei were collected to investigate the eclipse nature in the ultraviolet. The temperature of the B star has been determined, as approximately 30000K, based on the flux distributions during egress. Light curves of VV Cephei were reduced from the spectrophotometry of the IUE archival spectra. Three light curves at the center wavelengths of 2350 ${\AA}$, 2550 ${\AA}$ and 2850 ${\AA}$ have been analyzed by the modified Wilson and Devinney light curve program. The radii of the B star and M star were deduced to 0.05 and 0.22 of unit separation, respectively. The UV light curves show an evidence that the light was attenuated by the highly opaque atmosphere of the M star.

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Development of the sunshade hat with a large brim(Part I) -Development and test with manikins- (양산형 일광차단모의 개발(제1보) -고안 및 마네킹 착용실험-)

  • 김경수;최정화
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.8
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    • pp.1177-1185
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    • 2002
  • This study was to develop the sunshade hat which reduced stress from solar radiation and ultraviolet radiation (UV), in order to keep the farmer's health and to promote their work efficiency. The new sunshade hat with a large brim, special structure for ventilation, stability and portability was designed and tested with manikin heads outdoors. Two newly designed sunshade hats(A, B) and three existing hat were tested Sunshade hat A made of double fabric with aluminum coating-nylon and black cotton cloth with a polyester mix(T/C) was the most protective from solar radiation. Sunshade hat B with larger brim was the most protective from ultraviolet radiation, even though it was made of aluminum coating-nylon single fabric.

Betula Platyphylla var. Japonica Extract Prevent Ultraviolet C Light-induced Cell Damage in Chinese Hamster Fibroblast (V79-4) Cells

  • Lee, Mi-Kyoung;Kim, Jeong-Hee
    • International Journal of Oral Biology
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    • v.33 no.4
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    • pp.137-141
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    • 2008
  • The present study reports the protective properties of a total methanol extract of B. platyphylla var. japonica against ultraviolet (UV)-C irradiation. Pretreatment of Chinese hamster fibroblast (V79-4) cells with a total methanol extract significantly increased cell survival following $300\;J/m^2$ of UV-C irradiation. The total methanol extract was further fractionated into 5 fractions: n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these fractions, B. platyphylla var. japonica ethylacetate, butanol and water fractions showed significant protective effects against the cellular damage induced by UV-C irradiation. In order to elucidate the mechanism underlying this protective effect, DPPH (Editor note: abbreviations should be spelled out at first use.) radical scavenging and lipid peroxidation inhibitory activity were measured. Significant radical scavenging and lipid peroxidation inhibitory activities were observed for the ethylacetate fraction. In summary, the present data demonstrate that an extract of B. platyphylla var. japonica has a significant protective effect against UV-C irradiation. The underlying mechanism of this protective effect may involve radical scavenging and inhibition of lipid peroxidation by the B. platyphylla var. japonica extract.

UVB Photosynthesis of Vit, D3 and Fabrics (Part ll) - The animal study - (자외선에 의한 비타민 $D_3$ 합성과 직물(제2보) -동물 실험을 통하여 -)

  • Kim, Jeong-Hyeon;An, Ryeong-Mi;Song, Myeong-Gyeon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.22 no.5
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    • pp.646-653
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    • 1998
  • Because there is a great concern' today about the damaging effect of chronic exposure to sunlight the use of sunscreen providing the photoprotection effect against ultraviolet (UV) was widely increased. As a result of common use of level of photosynthetic Vit. D3 in human skin decreased these days. In our experiment the animals covered with fabrics with 50% (fabric B) and 100% (fabric A) protection rate against ultraviolet B (UVB) were used to measure serum 25(OH)D3, ALP, total clacium and phosphorus. Vitamin D deficiency diet group had no effect on concentration of serum phosphorus. But the concentrations of serum 25(OH)D9 and total calcium were more decreased in vitamin D deficiency diet rats than in normal diet rats. Alkaline phosphatase activity in sunlight irradiated groups covered with 50% (fabric B) and 100% (fabric A) WB protection fabrics was more significantly decreased than vitamin D deficiency diet group. In conclusion, sunlight irradiateted groups were compared to effective to protect born disease due to the Vit. D deficeincy group.

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Inhibitory effect of Mojaban (Sargassum fulvellum) extract on ultraviolet B-induced photoaging in hairless mouse skin (무모 마우스 피부에서 모자반 추출물의 자외선비(ultraviolet B)에 의해 유도된 광노화 억제 효과)

  • Rhim, Dong-Bin;Kim, Changhee;Hwang, Jae-Kwan
    • Korean Journal of Food Science and Technology
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    • v.52 no.5
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    • pp.467-475
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    • 2020
  • Ultraviolet radiation is a major cause of photoaging, characterized by wrinkle formation and skin dehydration. Mojaban (Sargassum fulvellum), belonging to the brown algae of the Sargassaceae family, exerts anti-inflammatory, antioxidant, and anti-atopic activities. Particularly, Mojaban extract alleviated ultraviolet B (UVB)-induced inflammatory responses in human keratinocytes and BALB/c mice. Here, the dorsal skin of hairless mice was exposed to UVB for photoaging. The mice were administrated 300 mg/kg Mojaban extract (S. fulvellum extract; SFE) daily. Phenotypically, SFE reduced wrinkle formation and epidermal thickness and increased skin elasticity. SFE increased hydroxyproline content by upregulating the expression of collagen-related genes and downregulating matrix metalloproteinase expression. Furthermore, SFE increased skin moisture content and inhibited transepidermal water loss. SFE upregulated the expression of involucrin, loricrin, and transglutaminase for cornified envelope formation as well as the expression of filaggrin and caspase-14 for natural moisturizing factors. Collectively, SFE may be employed as a nutraceutical ingredient for anti-photoaging.

The Changes of $Vit.D_2$ and $Vit.B_2$ Contents according to Ultraviolet rays and Cooking Methods of Mushrooms (버섯의 자외선조사와 조리조건에 따른 $Vit.D_2$$Vit.B_2$ 함량의 변화)

  • Oh, Hae-Sook;Yoon, Sun;Park, Hee-Ok
    • Journal of the Korean Society of Food Culture
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    • v.16 no.5
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    • pp.463-469
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    • 2001
  • This study was to investigate the effect of ultraviolet rays, soaking, boiling and baking to ergocalciferol ($Vit.D_2$) and riboflavin($Vit.B_2$) contents of mushrooms, Lentinus edodes, Pleurotus ostreatus and Agaricus bisporus. The results were as follow: 1. Mushrooms were exposed to ultraviolet rays Lentinus edodes : $10J/cm^2$, Pleurotus ostratus : $2J/cm^2$ and Agaricus bisporus : $2J/cm^2$. 2. Before exposing to ultraviolet rays, the ergocalciferol contents of mushrooms were all $0{\mu}g/g$ dry base, but after exposing to it , those of Lentinus edodes, Pleurotus ostreatus and Agaricus bisporus were $222.50{\pm}5.30{\mu}g/g$ dry base, $150.90{\pm}6.60{\mu}g/g$ dry base and $23.98{\pm}1.20{\mu}g/g$ dry base, respectively 3. Before and after exposing to ultraviolet rays, the riboflavin contents of Lentinus edoes, Pleurotus ostreatus and Agaricus bisporus were $18.22{\pm}0.71{\mu}g/g$ dry base and $11.72{\pm}0.50{\mu}g/g$ dry base, $4.57{\pm}0.20{\mu}g/g$ dery base and $3.26{\pm}0.15{\mu}g/g$ dry base, and $37.42{\pm}1.20{\mu}g/g$ dry base and $27.33{\pm}2.10{\mu}g/g$ dry base, respectively. 4. The ergocalciferol contents of mushrooms according to boiling time were not significantly different but the riboflavin contents of them were decreased according to the increase of boiling time. 5. The ergocalciferol and riboflavin contents of mushrooms were decreased according to the increase of NaCl concentration and baking temperature. 6. The ergocalciferol content of Lentinus edodes after a short time soaking at $80^{\circ}C$ was higher than a long time soaking at $20^{\circ}C,\;40^{\circ}C$ and $60^{\circ}C$.

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