• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.424-430
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• 2010

Immuno-modulatory activities of peptides from Asterias amurensis were investigated using a nano-encapsulation process. The molecular weights of the peptides in the range of 5-7 kDa were separated using Sephadex G-75 gel filtration. Eighty-five percent of the nano-particles were in the 300 nm range using dynamic light scattering. The cytotoxicity of the A. amurensis nano-particles against CCD-986sk human dermal fibroblast cells was 11.64% after adding 1.0 mg/mL of the samples, which was lower than that from the control (13.28% collagen). The secretion of $NO^-$ from macrophages was estimated as $40\;{\mu}M$ after adding 1.0 mg/mL of gelatin nano-particles, which was higher than the others. Prostaglandin $E_2$ production from UV-induced human skin cells decreased greatly to 860 pg/mL after adding 1.0 mg/mL of the samples. Confocal microscopy revealed that nano-particles effectively penetrated the cells within 1 hour. From these results, we consider that nano-encapsulation of the peptides from A. amurensis can improve their biological functions.

• Food Science and Preservation
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• v.21 no.2
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• pp.264-275
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• 2014

This study evaluated the improving efficacy of Lespedeza cuneata ethanol extract on skin photoaging induced by ultraviolet (UV) irradiation. The total polyphenol and flavonoid contents of the extract were respectively $134.98{\pm}1.70$ and $16.20{\pm}0.05$ mg/g, respectively. The superoxide anion radical scavenging activity and electron-donating ability of the extract were shown to be dependent on concentration, and the antioxidant ability was shown to be more effective in superoxide anion radical scavenging activity than in electron-donating ability under the same concentration conditions. In the in vivo test conducted using hairless mouse with skin photoaging induced by UVB irradiation, the skin erythema of the groups treated with the extract (AS) reduced to 28% of the control, and the skin moisture content increased to 131%.. The extract treatment of the UV-damaged skin improved the morphological and histopathological state of the skin. Furthermore, the SOD, GST and CAT activities in the skin tissue of the AS group increased, and the XO activity and TBARS generation decreased. With regard to the genes related to the photoaging skin, the expression of PAK, p38, c-Fos, c-Jun, TNF-${\alpha}$ and MMP-3 in the skin of the AS group were found to have decreased. It was therefore concluded that Lespedeza cuneata ethanol extract can reduce wrinkle formation in the skin due to the regulation of the gene expression caused by the exposure to UVB light.

• Journal of Radiation Protection and Research
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• v.32 no.2
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• pp.65-69
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• 2007

The effects of bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BLE) on the changes of ultraviolet (UV) light B radiation-induced apoptotic sunburn cell (SBC) and epidermal ATPase-positive dendritic cell (DC) in SKH1-hr or ICR mouse were investigated. The mice were treated with UVB ($200mJ/cm^2$) and were sacrificed 24 hours later. BLE (50 mg/kg of body weight) or vehicle (saline) was given i.p. at 36 and 12 hours before irradiation, and 30 minutes after irradiation. BLE cream (0.2%) or cream base (vehicle) was also topically treated at 24 hours and 15 minutes before irradiation, and immediately after irradiation. The skin of SKH1-hr mouse prepared from the back of untreated mice exhibited about 0.3 SBC/cm length of epidermis, and 24 hours after UV irradiation, the applied areas show an increased number of SBCs. But the frequency of UVB-induced SBC formation was significantly reduced by intraperitoneal injection (59.0%) and topical application (31.8%) of BLE extract. The numbers of DC in normal ICR mouse were $628.00{\pm}51.56\;or\;663.20{\pm}62.58\;per\;mm^2$ of ear epidermis. By 1 day after UVB treatment, the number of ATPase-positive $cells/mm^2$ were decreased by 39.0% or 27.1% in i.p. or topical application group with vehicle. The frequency of UVB ($200mJ/cm^2$)-induced DC decrease was reduced by treatment of BLE as 25.7% in i.p. group and 3.2% in topical application group compared with the irradiation control group. The results presented herein that BLE administration could reduce the extent of skin damages produced by UVB.

• Applied Chemistry for Engineering
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• v.19 no.3
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• pp.299-303
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• 2008

A thermally cross-linkable polymer, poly[(2,5-dimethoxy-1,4-phenylenevinylene)-alt-(1,4-phenylenevinylene)] (Cross-PPV), was synthesized by the Heck coupling reaction. In order for the polymer to be cross-linkable, 20 mol% excess divinylbenzene was added. The chemical structure of Cross-PPV and thermally crosslinked Cross-PPV were confirmed by FT-IR spectroscopy. From the FT-IR, UV-Vis, and PL spectral data, thermally crosslinked Cross-PPV was insoluble in common organic solvents. The HOMO and LUMO energy level of thermally cross-linked Cross-PPV were estimated -5.11 and -2.56 eV, respectively, which were determined by the cyclic voltammetry and UV-Vis spectroscopy. From the energy level data, one can easily notice that thermally crosslinked Cross-PPV can be used for hole injection layer effectively. Bilayer structured device (ITO/crosslinked Cross-PPV/PM-PPV/Al) was fabricated using poly(1,4-phenylenevinylene-(4-dicyanomethylene-4H-pyran)-2,6-vinylene-1,4-phenylenevinylene-2,5-bis(dodecyloxy)-1,4-phenylenevinylene (PM-PPV) as the emitting layer, which have HOMO and LUMO energy levels of -5.44 eV and -3.48 eV, respectively. The bilayered device had much enhanced the maximum efficiency (0.024 cd/A) and luminescence ($45cd/m^2$) than those of a single layer device (ITO/PM-PPV/Al, 0.003 cd/A, $3cd/m^2$). The enhanced performance originated from that fact that cross-linked Cross-PPV facilitatse the hole injection to the emissive layer and the injected hole and electron from ITO and Al are recombined in emitting layer (PM-PPV) effectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.189-189
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• 2012

Lead sulfide (PbS) nanocrystal quantum dots (NQDs) are promising materials for various optoelectronic devices, especially solar cells, because of their tunability of the optical band-gap controlled by adjusting the diameter of NQDs. PbS is a IV-VI semiconductor enabling infrared-absorption and it can be synthesized using solution process methods. A wide choice of the diameter of PbS NQDs is also a benefit to achieve the quantum confinement regime due to its large Bohr exciton radius (20 nm). To exploit these desirable properties, many research groups have intensively studied to apply for the photovoltaic devices. There are several essential requirements to fabricate the efficient NQDs-based solar cell. First of all, highly confined PbS QDs should be synthesized resulting in a narrow peak with a small full width-half maximum value at the first exciton transition observed in UV-Vis absorbance and photoluminescence spectra. In other words, the size-uniformity of NQDs ought to secure under 5%. Second, PbS NQDs should be assembled carefully in order to enhance the electronic coupling between adjacent NQDs by controlling the inter-QDs distance. Finally, appropriate structure for the photovoltaic device is the key issue to extract the photo-generated carriers from light-absorbing layer in solar cell. In this step, workfunction and Fermi energy difference could be precisely considered for Schottky and hetero junction device, respectively. In this presentation, we introduce the strategy to obtain high performance solar cell fabricated using PbS NQDs below the size of the Bohr radius. The PbS NQDs with various diameters were synthesized using methods established by Hines with a few modifications. PbS NQDs solids were assembled using layer-by-layer spin-coating method. Subsequent ligand-exchange was carried out using 1,2-ethanedithiol (EDT) to reduce inter-NQDs distance. Finally, Schottky junction solar cells were fabricated on ITO-coated glass and 150 nm-thick Al was deposited on the top of PbS NQDs solids as a top electrode using thermal evaporation technique. To evaluate the solar cell performance, current-voltage (I-V) measurement were performed under AM 1.5G solar spectrum at 1 sun intensity. As a result, we could achieve the power conversion efficiency of 3.33% at Schottky junction solar cell. This result indicates that high performance solar cell is successfully fabricated by optimizing the all steps as mentioned above in this work.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.412-417
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• 2011

A series of homobinuclear complexes of the type [$M_2L(NO_3)_n(H_2O)_m$] where M=$UO_2$(VI), ZrO(IV), Th(IV); L=3-benzylidine-imino-5-p-sulphonamido phenyl azo-2-thiohyatoin(bispt), 3-furfurylidine-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin(fispt),3-pyridyl-2'-methylene-imino-5-p-sulphonamido phenyl azo-2-thiohydantoin(pmispt) and 3-thienyl-2'-methylene-imino-5-p-sulphoanamido phenyl azo-2-thiohydantoin(tmispt); n=8 for Th(IV) and 4 for others, m=4 for bispt and 3 for others have been synthesized and characterized on the basis of elemental analysis, thermal analysis, molar conductance, magnetic moment and spectroscopic data (IR, electronic and $^1H$-NMR). In the light of this information, the ligands can be visualized as tetradentate co-ordinating through azomethine nitrogen, carbonyl oxygen to one metal centre where as azo nitrogen and thioimido nitrogen to the other metal centre yielding homo binuclear complexes of the above composition. The fungi toxicity of the ligands & their zirconyl complexes against some fungal pathogen has been studied.

• Korean Journal of Environmental Biology
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• v.35 no.1
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• pp.47-56
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• 2017

This study investigates the spatial and temporal variations of moth diversity of Bulgapsan Mountain, Younggwang, Jeonnam. Moth collecting was carried out using a UV light trap at three different sites from February to October 2016 (5 times). A total of 177 moth species and 911 individuals in 17 families were identified. The family Geometridae (51 species and 282 individuals) was the most dominant in the numbers of species and individuals, followed by Erebidae (46 species, 248 individuals), Noctuidae (34 species, 219 individuals) and others. Seasonal change of the number of species and individuals showed a M-shaped pattern with May and July peaks. The Chao 1 estimated number of species using the observed species was 224~326 species, but the graph did not reach an asymptote. Among the surveyed sites, the Neolitsea sericea community showed the highest numbers of species and individuals.

• Toxicological Research
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• v.33 no.1
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• pp.43-48
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• 2017

With ultraviolet and visible light exposure, some pharmaceutical substances applied systemically or topically may cause phototoxic skin irritation. The major factor in phototoxicity is the generation of reactive oxygen species (ROS) such as singlet oxygen and superoxide anion that cause oxidative damage to DNA, lipids and proteins. Thus, measuring the generation of ROS can predict the phototoxic potential of a given substance indirectly. For this reason, a standard ROS assay (ROS assay) was developed and validated and provides an alternative method for phototoxicity evaluation. However, negative substances are over-predicted by the assay. Except for ultraviolet A (UVA), other UV ranges are not a major factor in causing phototoxicity and may lead to incorrect labeling of some non-phototoxic substances as being phototoxic in the ROS assay when using a solar simulator. A UVA stimulator is also widely used to evaluate phototoxicity in various test substances. Consequently, we identified the applicability of a UVA simulator to the ROS assay for photoreactivity. In this study, we tested 60 pharmaceutical substances including 50 phototoxins and 10 non-phototoxins to predict their phototoxic potential via the ROS assay with a UVA simulator. Following the ROS protocol, all test substances were dissolved in dimethyl sulfoxide or sodium phosphate buffer. The final concentration of the test solutions in the reaction mixture was 20 to $200{\mu}M$. The exposure was with $2.0{\sim}2.2mW/cm^2$ irradiance and optimization for a relevant dose of UVA was performed. The generation of ROS was compared before and after UVA exposure and was measured by a microplate spectrophotometer. Sensitivity and specificity values were 85.7% and 100.0% respectively, and the accuracy was 88.1%. From this analysis, the ROS assay with a UVA simulator is suitable for testing the photoreactivity and estimating the phototoxic potential of various test pharmaceutical substances.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.379-386
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• 1996

Photosensitive compound, 1-methyl-4-[2-(4-diethylacetylphenyl)ethenyl] pridinium methosulfate(SbQ-A salt), was synthesized from dimethyl sulfate, terephthalaldehyde mono-(diethylacetal) and 4-picoline. SbQ-A salts were reacted with poly(vinyl alcohol)s, (PVA) in aqueous solution with phosphoric acid as catalyst to give photosensitive PVA-SbQ with different SbQ content and molecular weight. Relative photosensitivity of PVA-SbQ was determined by gray scale(GS) method. The rotative sensitivity of PVA-SbQ increased with increasing amount of bound SbQ in the case of high molecular weight(MW=77,000-79,000g/mol) as substrate and decreased with decreasing molecular weight of PVA with about constant(1.3mol%) amount of bound SbQ. The most sensitive polymer was obtained when SbQ group content in PVA-SbQ reached about 2.63mol% in the case of high molecular weight(77,000-79,000g/mol) PVA. This sample showed 90 times greater sensitivity than dichromated PVA as reference photosensitive system. PVA-SbQ photosensitive polymer synthesized was applied to the photolithographic screening process of phosphor on the panel of cathode ray tube(CRT). Phosphor slurry was made with PVA-SbQ, phosphor, a small amount of surfactant and other additives using water as medium. The slurry was coated onto panel, dried by heater, exposed to UV light and then developed by distilled water. When a small amount of cationic surfactant such as cetyltrimethylammonium chloride was used in the slurry formulation, the sharpness of phosphor pattern was equal to or better than that of dichromated PVA photosensitive polymer system used currently.

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.7-13
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• 2007

The present study investigated the effects of follicle stimulating hormone (FSH) and human chorionic gona-dotrophin (hCG) on the nuclear maturation of canine oocytes. Oocytes were recovered from mongrel female ovaries in various reproductive states; follicular, luteal or anestrous stage. Oocytes were cultured in sserum-free tissue culture medium (TCM)-199 supplemented with various concentrations of FSH (Exp. 1: 0, 0.5, 1.0 or 10 IU) or hCG (Exp.2:0, 0.5, 1.0 or 10 IU) or both (Exp. 3:1 IU FSH +1 IU hCG) for 72 hr to determine the effective concentration of these hormones, and to examine their combined effect. After maturation culture, oocytes were denuded in PBS containing 0.1% (w/v) hyaluronidase by gentle pipetting. The denuded oocytes were stained with $1.9\;{\mu}M$. Hoechst 33342 in glycerol and the nuclear state of oocytes was evaluated under UV light. More (p<0.05) oocytes matured to MII stage when follicular stage oocytes were supplemented with 1 IU FSH (6.2%) compared with the control, 0.1 or 10.0 IU FSH (0 to 1.2%). Significantly higher (p<0.05) maturation rate to MII stage was observed in follicular stage oocytes supplemented with 1.0 IU hCG (7.2%) compared with the control or other hCG supplemented groups (0 to 1.5%). However, the combination of FSH and hCG did not improve the nuclear maturation rate of canine oocyte (2.4 %) compared with FSH (6.2%) and hCG alone (7.2%). In conclusion, FSH or hCG alone significantly increased the maturation of canine oocytes to MII stage.