Sunlight, and in particular its UV component, is the major environmental trigger that underlies the major signs of human skin and skin cancer in general. Therefore, this study was carried out to investigate the UV protection effects of R. coreanus. R. coreanus was extracted by ultra high pressure extraction process at 500 MPa and 30℃ for 5 and 15 minutes. The cytotoxicity of the extracts extracted by ultra high pressure process on human dermal fibroblast cell CCD-986sk, human kidney normal cell HEK293, and human lung normal cell HEL299 was measured as 17.5%, 16.5% and 14.0%, respectively in adding 1.0 mg/ml of the samples, which was much lower than that from conventional water extraction method at 100℃ as 23.2%, 22.5%, 21.2%. The secretion of NO- from macrophage showed 15.9 μM on the R. coreanus extract from this process, which was higher than others. Prostaglandin E2 (PGE2) production from UV-induced human skin cells was also greatly decreased down to 510 pg/ml, compared to the control. From the results, we considered that the extracts from R. coreanus could be potent natural materials for skin anti-inflammation agent, and could be used as a potential anti-aging for the photo-damaged skin.

This study has carried out to evaluate the effect of NaCl as electrolyte of single (electrolysis and UV process) and complex (electrolysis/UV) processes for the purpose of removal and mineralization of Rhodamine B (RhB) dye in water. It also evaluated the synergetic effect on the combination of electrolysis and UV process. The experimental results showed that RhB removal of UV process was decreased with increase of NaCl, while RhB removal of electrolysis and electrolysis/UV process was increased with increase of NaCl. The decolorization rate of the RhB solution in every process was more rapid than the mineralization rate identified by COD removal. The latter took longer time for further oxidation. Absorption spectra of an aqueous solution containing RhB showed a continued diminution of the RhB concentration in the bulk solution: concomitantly, no new absorption peaks appeared. This confirmed the decolorization of RhB, i.e., the breakup of the chromophores. It was observed that RhB removal in electrolysis/UV process is similar to the sum of the UV and electrolysis. However, it was found that the COD of RhB could be degraded more efficiently by the electrolysis/UV process than the sum of the two individual process. A synergetic effect was demonstrated in electrolysis/UV process.

Reductions in the ozone column have led to substantial increase in UV-B radiation at the Earth's surface with the amount and intensity dependent on atmospheric and geographic factors. Our objectives were to understand the effect of UV-B radiation on photosynthesis and carbohydrate synthesis of soybean, and to establish an indicator to select resistant soybean cultivar against UV-B radiation. Soybean seeds (cv. Daepungkong) were sown and grown for 4 weeks in an environmentally controlled chamber. UV-B radiation was delivered to plants for four hours, each day, from 10:00 to 14:00 h by five fluorescent UV lamps. A distance of 1 m from lamps to the top of plants was always maintained throughout the experiment. The biologically effective UV-B radiation level was 21.6 kJ m-2 d-1 using the generalized plant responses action spectrum normalized at 300 nm. The damage of soybean leaves was optically observed at the second day of UV-B radiation, and leaf veins were first injured. Photosynthetic rate was reduced after 2 days of UV-B radiation, and, at 5 days, it was a half level (6.3 μmol m-2 s-1) compared with control (12.1 μmol m-2 s-1). UV-B radiation led to the reduction of stomatal conductance around 5 days of treatment. The decrease in stomatal conductance means the reduction of leaf transpiration and the influx of carbon dioxide. Also, the reduction of photosynthetic rate caused an accumulation of the intercellular carbon dioxide. It is suggested that photosynthetic characteristics can be used an indicator to select UV-B-resistant soybean cultivar.

In the present study we studied the growth, photosynthetic traits and protective mechanisms against oxidative stress in the primary loaves of cucumber (Cucumis sativus L.) seedlings with or without UV-B treatment. Cucumber seedings were irradiated with UV-B for 10 days in environment-controlled growth chambers. The primary leaves irradiated with UV-B showed reduction in leaf length and decreased biomass production. The reduced biomass production seemed to be due to a negative effect of UV-B radiation on the photosynthetic process. Changes in chemical properties of leaf, such as chi a/b ratio affected photosynthesis. UV-B significantly affected chl b content compared with chi a in the light harvesting complex resulting reduced photosynthetic activity Fv/Fm decreased with an UV-B stress, suggesting that the photosynthetic apparatus, and particularly, PS II was damaged under UV-B stress. Malondialdehyde(MDA) concentration which represents the state of membrane lipid peroxidation Increased significantly under UV-B stress confirming an oxidative stress. UV-B exposure with SA solution(0.1-1.0 mM) can partially ameliorated some of the detrimental effects of UV-B stress. Leaf injuries including loss of chlorophyll and decreased ratio of Fv/Fm were reduced with combined application of UV-B and SA. ABA and JA showed similar mode of action in physiological effects on photosynthetic activities though the levels were lower than those from SA treated plants. Chloroplast ultrastructure was also affected by UV-B exposure. The thickness of leaf tissue components decreased and the number of grana and thylakoids was reduced in chloroplast applied UV-B or SA alone. At combined stress granal and stromal thylakoids were less affected. The leaves under combined stress acquired a significant tolerance to oxidative stress. From these results, it can be suggested that SA may have involved a protective role against UV-B induced oxidative damage.

The effect of UV on the mortality rate of toxic dinoflagellate Amphidinium carterae causing a red tide in the coastal area of south Korea was investigated in the batch and continuous-scale reactor equipped with ultraviolet irradiation-apparatus. Degussa P25 titanium oxide, a photocatalyst proved to be effective for the mortality of Amphidinium carterae supplied with photocatalyst and UV radiation were greater than 95% in 2 minutes of UV radiation and the rate were higher than that by UV-radiation without titanium dioxide in the batch and continuous-flow scale reactor. The mortality time of Amphidinium carterae increased with the cell density under UV-illumination in the batch scale reactor. The mortality rate in the density of 5.0×104 cells/mL at the same experimental condition was more than 90% in 4 minutes in the continuous flow scale reactor. The percentage of 99.9±0.1% of Amphidinium carterae in the density of 5.0×104 cells/mL was died in 20 minutes when the phytoplankton was illuminated with UV-radiation without photocatalyst.