• Ocean and Polar Research
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• v.40 no.4
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• pp.281-288
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• 2018

The transmission of solar light according to the distribution of chromophoric dissolved organic matter (CDOM) was measured in the Pacific Arctic Ocean. The Research Vessel Araon visited the ice-covered East Siberian and Chukchi Seas in August 2016. In the Arctic, solar [ultraviolet-A (UV-A), ultraviolet-B (UV-B), and photosynthetically active radiation (PAR)] radiation reaching the surface of the ocean is primarily protected by the distribution of sea ice. The transmission of solar light in the ocean is controlled by sea ice and dissolved organic matter, such as CDOM. The concentration of CDOM is the major factor controlling the penetration depth of UV radiation into the ocean. The relative CDOM concentration of surface sea water was higher in the East Siberian Sea than in the Chukchi Sea. Due to the distribution of CDOM, the penetration depth of solar light in the East Siberian Sea (UV-B, $9{\pm}2m$; UV-A, $13{\pm}2m$; PAR, $36{\pm}4m$) was lower than in the Chukchi Sea (UV-B, $15{\pm}3m$; UV-A, $22{\pm}3m$; PAR, $49{\pm}3m$). Accelerated global warming and the rapid decrease of sea ice in the Arctic have resulted in marine organisms being exposed to increased harmful UV radiation. With changes in sea ice covered areas and concentrations of dissolved organic matter in the Arctic Ocean, marine ecosystems that consist of a variety of species from primary producers to high-trophic-level organisms will be directly or indirectly affected by solar UV radiation.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.65-73
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• 2016

The aim of this study was to investigate the UV-resistance of radiation-resistant bacteria isolated from the water of Han River, South Korea. The water sample was irradiated with 3 kGy gamma radiation prior to isolation. Radiation-resistant bacterial strains were isolated by standard serial dilution method on R2A and 1/10 diluted R2A agar. The resulting purely isolated 60 cultures of bacteria were analysed for UV resistance and used in further studies. Based on the comparative analyses of 16S rRNA gene sequences, the bacterial isolates were divided into 3 phyla (4 genera): the phylum Deinococcus-Thermus (the genus Deinococcus) was 61.7%, Bacteroidetes (Hymenobacter and Spirosoma) was 23.4%, and Firmicutes (Exiguobacterium) was 15%. The results suggested that twenty-nine isolates are candidates new species belonging to Deinococcus, Hymenobacter, and Spirosoma, or other new genera. Nine bacterial strains were selected among the novel candidates and the UV-resistance analysis was conducted. All the candidate bacterial strains showed high UV resistance, similar to that of D. radiodurans R1.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.17 no.1
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• pp.1-17
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• 1991

Multiport-600 Solar SimulatorR is one of the most recent and convenient in-strument for evaluation of sun protection factor(SPF). In this study, we examined the practicability of the SPF determining system using Multiport -600 and the effects of several factors-light sources, seasons and experimental animals-on the minimal erythema dose(MED) and SPF. We also tested the UV sensitivity according to the sites of Korean people, And the ultraviolet radiation reaching the earth's surface In Seoul have been observed for one year. As a result of this study, the determinig system for SPF using Multiport-600 was proved to be a good system in accuracy and time-saving. The biological activity of fluorescence UV lamp of PUVA-800R was significantly higher than natural light or solar simulator with Xe arc lamp, and the determined MED became lower in inverse proportion to room temperature rise. Skin sensitivity by ultraviolet adiation was hights. in order \circled1 back \circled2 inns, upper arm \circled3 outer upper arm \circled4 foream. We also observed that UV radiation intensity was highest at noon in july and 1 sun burn unit(MED) was 28 minutes at that time.

• Journal of The Korean Astronomical Society
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• v.33 no.1
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• pp.57-73
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• 2000

We have done a spectroscopic study of the solar transition region using high resolution UV & EUV data obtained by SUMER(Solar Ultraviolet Measurements of Emitted Radiation) on board SOHO(Solar and Heliospheric Observatory). Optically thin and conspicuous emission lines observed at the solar limb are carefully selected to acquire average values of physical parameters for the quiet region as a function of radial distance. Our main results found from the present study can be summarized as follows. 1) Nonthermal velocities estimated from various UV lines do not decrease with height at least within one total line intensity scale height above the limb. 2) Nonthermal velocity distribution with temperature is very similar to that of the disk center, in the sense that its peak is located around $2{\times}10^5 K$, but the value is systematically larger than that of the disk. 3) It is found that nonthermal velocity is inversely proportional. to quadratic root of electron density up to about 10 arc seconds above the limb, i.e. ${\xi}\~N_e^{-1/4}$, implying that the observed nonthermal broadening can be attributed to Alfven waves passing through the medium. 41 Electron density estimated from the O V 629/760 line ratio is found to range from about $1{\times}10^{10}cm^{-3}$ to $2{\times} 10^{12}cm^{-3}$ in the transition region.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.67.2-67.2
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• 2013

Part of mid-J CO emission detected by the Herschel/PACS observations of embedded young stellar objects (YSOs) has been attributed to the UV-heated outflow walls. We have applied our newly developed self-consistent models of Photon Dominated Region (PDR) and Non-LTE line Radiative transfer In general Grid (RIG) to the Herschel FIR CO observations. If the black body radiation of T = 15,000 K is used, the observed mid-J CO line fluxes can be produced in inner dense regions (n ${\geq}$ 106 cm-3) with -4.5 ${\leq}$ log Gdust/n ${\leq}$ -2.5, where gas temperatures are larger than 300 K and CO abundances are ${\geq}$ 10-5, along the UV-heated outflow walls. The contribution of the UV heated outflow cavity wall in Class I seems to be larger than that in Class 0.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.400-406
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• 2010

Etiolation of plant leaves evoke to be photosynthetically inactive because plant leaves are unable to convert photochlorophyllide to chlorophyllide in the absence of light. In addition, UV-B radiation plays an important role in photomorphogenesis and excessive UV-B radiation decreases photosynthesis and causes to damage to cellular DNA. In the present study, two electrical lights obtained with the ultraviolet lamp and moderate lamp were employed to young plants soybean (Glycine max Merr. var Seoritae). After treatment of different lights, young plants were harvested for the determination of pigment contents and chlorophyll fluorescence. The contents of carotenoids and anthocyanins were significantly enhanced with the excessive UV-B radiation. Excessive UV-B light reduced dramatically photosynthetic efficiency causing an irreversible damage on PSII in comparison to the controls treated under normal illumination. As the treatment of normal illumination after dark treatment, the contents of carotenoids and anthocyanains were not changed in the leaves and photosynthetic ability were retained. Therefore, Seoritae soybean leaves might protect themselves from excessive UV-B radiation with up-regulation of antioxidants.

• Molecular & Cellular Toxicology
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• v.3 no.1
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• pp.23-30
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• 2007

The effects of high energy short wave solar radiation on human skin have received much publicity as the major cause of accelerated skin ageing and of skin cancers. To meet public demand, the cosmetic industry has developed sun protection factor products, which contain a variety of so-called "UV filters", among others benzophenone (BP) and its metabolites are the widely used UV filters. UV filters are also used to prevent UV light from damaging scents and colors in a variety of cosmetics products and to protect of plastic products against light-induced degradation. There are many variants of BP in use. In this respect, to regulate and to evaluate the hazardous effect of BP-type UV filters will be important to environment and human health. The genotoxicity of 7 BP-type UV filters was evaluated in L5178Y $(tk^{+/-})$ mouse lymphoma cells in vitro. BP, benzhydrol, 4-hydroxybenzophenone 2-hydroxy-4-methoxybenzophenone and 2, 4-dihydroxybenzophenone did not induce significant mutation frequencies both in the presence and absence of metabolic activation system. 2, 2'-Dihydroxy-4-methoxybenzophenone appeared the positive results at the highest dose, i.e. 120.4 ${\mu}g/mL$ only in the absence of metabolic activation system. And also, 2, 3, 4-trihydroxybenzophenone revealed a significant increase of mutation frequencies in the range of 138.1-207.2 ${\mu}g/mL$ in the absence of metabolic activation system and 118.3-354.8 ${\mu}g/mL$ in the presence of metabolic activation system. Through the results of MLA with 7 BP-type UV filters in L5178Y cells in vitro, we may provide the important clues on the genotoxic potentials of these BP-type UV filters.

• Journal of Radiation Protection and Research
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• v.33 no.3
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• pp.87-91
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• 2008

We induced the activation of melanocytes in the epidermis of C57BL/6 mice by ultraviolet B (UVB) irradiation and observed the effect of Bu-Zhong-Yi-Qi-Tang (BZYQT) on the formation, and decrease of UVB-induced epidermal melanocytes. C57BL/6 mice were irradiated by UVB $80\;mJ/cm^2$ (0.5 mW/sec) daily for 7 days, and BZYQT was intraperitoneally or topically applied pre- or post-irradiation. For the estimation of change of epidermal melanocytes, light microscopic observation with dihydroxyphenylalanine (DOPA) stain was performed. Split epidermal sheets prepared from the ear of untreated mice exhibited 11-16 melanocytes/$mm^2$, and one week after UV irradiation, the applied areas show an increased number of strongly DOPA-positive melanocytes with stout dendrites. But intraperitoneal or topical treatment with BZYQT before each irradiation interrupted UVB-induced pigmentation and resulted in a marked reduction in the number of epidermal melanocytes as compared to radiation control skin. The number and size of DOPA-positive epidermal melanocytes were also significantly decreased in intraperitoneally injected or topically applicated group after irradiation with BZYQT at 3rd and 6th weeks after irradiation. The present study suggests the BZYQT as inhibitor of UVB-induced pigmentation and depigmenting agent.

• Journal of Ginseng Research
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• v.44 no.2
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• pp.274-281
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• 2020

Background: Ultraviolet (UV) goes through the epidermis and promotes release of inflammatory cytokines in keratinocytes. Granulocyte-macrophage colony-stimulating factor (GM-CSF), one of the keratinocyte-derived cytokines, regulates proliferation and differentiation of melanocytes. Extracellular signal-regulated kinase (ERK1/2) and protein kinase C (PKC) signaling pathways regulate expression of GM-CSF. Based on these results, we found that ginsenoside Rh3 prevented GM-CSF production and release in UV-B-exposed SP-1 keratinocytes and that this inhibitory effect resulted from the reduction of PKCδ and ERK phosphorylation. Methods: We investigated the mechanism by which ginsenoside Rh3 from Panax ginseng inhibited GM-CSF release from UV-B-irradiated keratinocytes. Results: Treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) or UV-B induced release of GM-CSF in the SP-1 keratinocytes. To elucidate whether the change in GM-CSF expression could be related to PKC signaling, the cells were pretreated with H7, an inhibitor of PKC, and irradiated with UV-B. GM-CSF was decreased by H7 in a dose-dependent manner. When we analyzed which ginsenosides repressed GM-CSF expression among 15 ginsenosides, ginsenoside Rh3 showed the largest decline to 40% of GM-CSF expression in enzyme-linked immunosorbent assay. Western blot analysis showed that TPA enhanced the phosphorylation of PKCδ and ERK in the keratinocytes. When we examined the effect of ginsenoside Rh3, we identified that ginsenoside Rh3 inhibited the TPA-induced phosphorylation levels of PKCδ and ERK. Conclusion: In summary, we found that ginsenoside Rh3 impeded UV-B-induced GM-CSF production through repression of PKCδ and ERK phosphorylation in SP-1 keratinocytes.

• Korean Journal of Materials Research
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• v.9 no.4
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• pp.409-413
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• 1999

Recently, the polymeric insulators have been accepted in several countries for the outdoor high voltage applications. In comparison with the conventional porcelain, polymeric insulators offer various advantages such as light weight, superior vandal resistance and better contamination performance. The outdoor polymeric insulating materials such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged such as silicone rubber, ethylene propylene diene monomer(EPDM), ethylene vinyl acetate(EVA) and epoxy are aged under the various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-under the various natural environment with the long-term performance in outdoor. In this paper, the effects of UV-ray on the surface of silicone rubber were investigated by using the weather-Ometer. The accelerated aging stresses were simulated by UV radiation, high temperature and humidity as well as water spray. These aging characteristics were examined through contact angle measurements, tracking resistance test, FT-IR and SEM/EDS analysis. The experimental results showed that tracking resistance decreases with increase in the UV-ray irradiation period. But the surface of silicone rubber kept hydrophobicity. It is found that the inorganic filler such as)$ Al(OH_3$ improves tracking resistance and the $Tio_2$is very effective in preventing degradation of silicone rubber surface from UV-ray.