• Current Photovoltaic Research
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• v.8 no.1
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• pp.33-38
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• 2020

Single-phased SnS thin films have been prepared by RF magnetron sputtering at various deposition pressures. The effect of deposition pressure on the structural and optical properties of polycrystalline SnS thin films was studied using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible-near infrared (UV-Vis-NIR) spectrophotometer. The XRD analysis revealed the orthorhombic structure of the SnS thin films oriented along the (111) plane direction. As the deposition pressure was increased from 5 mTorr to 15 mTorr, the intensity of the peak on the (111) plane increased, and the intensity decreased under the condition of 20 mTorr. The binding energy difference at the Sn 3d_5/2 and S 2p_3/2 core levels was about 324.5 eV, indicating that the SnS thin film was prepared as a pure Sn-S phase. The optical properties of the SnS thin films indicate the presence of direct allowed transitions with corresponding energy band gap in the rang 1.47-1.57 eV.

• Nutrition Research and Practice
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• v.10 no.4
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• pp.371-376
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• 2016

BACKGROUND/OBJECTIVES: Chronic ultraviolet (UV) exposure-induced reactive oxygen species (ROS) are commonly involved in the pathogenesis of skin damage by activating the metalloproteinases (MMP) that break down type I collagen. Adenophora remotiflora (AR) is a perennial wild plant that inhabits Korea, China, and Japan. The present study investigated the protective effects of AR against UVB-induced photo-damage in keratinocytes. MATERIALS/METHODS: An in vitro cell-free system was used to examine the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and nitric oxide (NO). The effect of AR on ROS formation, antioxidant enzymes, elastase, MMP-1 level, and mRNA expression of MMP-1 were determined in UVB-irradiated human keratinocyte HaCaT cells. RESULTS: AR demonstrated strong DPPH free radical and NO scavenging activity in a cell-free system exhibiting $IC_{50}$ values of 1.88 mg/mL and 6.77 mg/mL, respectively. AR pretreatment dose-dependently attenuated the production of UVB-induced intracellular ROS, and antioxidant enzymes (catalase and superoxide dismutase) were enhanced in HaCaT cells. Furthermore, pretreatment of AR prevented UVB-induced elastase and collagen degradation by inhibiting the MMP-1 protein level and mRNA expression. Accordingly, AR treatment elevated collagen content in UVB-irradiated HaCaT cells. CONCLUSION: The present study provides the first evidence of AR inhibiting UVB-induced ROS production and induction of MMP-1 as a result of augmentation of antioxidative activity in HaCaT human keratinocytes. These results suggest that AR might act as an effective inhibitor of UVB-modulated signaling pathways and might serve as a photo-protective agent.

• Journal of Microbiology and Biotechnology
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• v.21 no.10
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• pp.1036-1042
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• 2011

The exopolysaccharide botryosphaeran ($EPS_{GLC}$; a ($1{\rightarrow}3$)($1{\rightarrow}6$)-${\beta}$-D-glucan from Botryosphaeria rhodina MAMB-05) was sulfonated to produce a water-soluble fraction ($EPS_{GLC}$-S) using pyridine and chlorosulfonic acid in formamid. This procedure was then repeated twice to produce another fraction ($EPS_{GLC}$-RS) with a higher degree of substitution (DS, 1.64). The purity of each botryosphaeran sample (unsulfonated and sulfonated) was assessed by gel filtration chromatography (Sepharose CL-4B), where each polysaccharide was eluted as a single symmetrical peak. The structures of the sulfonated and re-sulfonated botryosphaerans were investigated using ultraviolet-visible (UV-Vis), Fourier-transform infrared (FT-IR), and $^{13}C$ nuclear magnetic resonance ($^{13}C$ NMR) spectroscopies. $EPS_{GLC}$ and $EPS_{GLC}$-RS were also assayed for anticoagulation activity, and $EPS_{GLC}$-RS was identified as an anticoagulant.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1357-1364
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• 2013

Human skin is continuously exposed to ultraviolet (UV)-induced photoaging. UVA increases the activity of MMP-1 in dermal fibroblasts through mitogen-activated protein kinase (MAPK), p38, signaling. The irradiation of keratinocytes by UVA results in the secretion of the inflammatory cytokine, tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and the stimulation of MMP-1 in normal human dermal fibroblasts (NHDFs). Lipoteichoic acid (LTA) is a component of the cell wall of gram-positive Lactobacillus spp. of bacteria. LTA is well known as an anti-inflammation molecule. LTA of the bacterium Lactobacillus plantarum has an anti-photoaging effect, but the potential anti-photoaging effect of the other bacteria has not been examined to date. The current study showed that L. sakei LTA (sLTA) has an immune modulating effect in human monocyte cells. Our object was whether inhibitory effects of sLTA on MMP-1 are caused from reducing the MAPK signal in NHDFs. It inhibits MMP-1 and MAPK signaling induced by UVA in NHDFs. We also confirmed effects of sLTA suppressing TNF-${\alpha}$ inducing MMP-1 in NHDFs.

• YAKHAK HOEJI
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• v.54 no.4
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• pp.295-299
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• 2010

The aim of this study was to develop and validate for determination of alibendol in human plasma by HPLC method. After precipitation of 500 ${\mu}l$ plasma samples by 50% methanol 50 ${\mu}l$ and 60% perchloric acid 30 ${\mu}l$ and the supernatant 50 ${\mu}l$ was injected into HPLC. The assay was performed isocratically using 10 mM potassium phosphate (pH 3.0) and acetonitrile (80 : 20, v/v) as mobile phase. The $C_{18}$ column (particle size $3.5{\mu}m$, $4.6{\times}50$ mm, Zorbax Eclipse) was used as a solid phase. The mobile phase was delivered at a flow-rate of 1.7 ml/min, detection was by ultraviolet absorption at 232 nm and concentrations were calculated on the basis of peak areas. In these conditions, alibendol can be separated from ethylparaben, the internal standard, and endogenous substances. The retention times of alibendol and ethylparaben were just about 2.6 and 3.5 minutes, respectively. This rapid HPLC method was validated by examining the precision and accuracy for inter- and intra-day analysis. The standard curve was linear ($R^2$=1.0000) over the concentration range of 0.05~20 ${\mu}g$/ml. The inter-day relative standard deviation (R.S.D.) and accuracy were 0.2~12.2% and 94.4~101.2% (82.7% at the lower limit of quatitation). The intra-day R.S.D. and accuracy were 0.1~11.8% and 98.8~102.5%, respectively. The method was successfully applied to the determination of alibendol in plasma for a pharmacokinetic study.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.4
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• pp.137-146
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• 2011

Vertically well-aligned ZnO nanowire (NW) arrays were synthesized directly on GaN/sapphire and Si substrate from Zn vapor deposition without catalysts. Experimental results showed that the number density, diameter, crystallinity and degree of the alignment of ZnO NWs depended strongly on both the substrate position and kind of the substrates used for the growth. The photoluminescence (PL) characteristics of the grown ZnO NW arrays exhibit a strong and sharp ultraviolet (UV) emission at 379 nm and a broad weak emission in the visible range, indicating that the obtained ZnO NWs have a high crystal quality with excellent optical properties. The as-grown ZnO NWs were characterized by using scanning electron microscopy (SEM), high resolution transmission electronic microscopy (HR-TEM), and X-ray diffraction (XRD).

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2666-2670
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• 2011

High-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) were used to identify five active components in the modified herbal decoction Bo-Yang-Hwan-O-Tang (mBHT), i.e., amygdalin, decursin, paeoniflorin, salvianolic acid B, and calycosin-7-O-${\beta}$-D-glycoside. These components were identified by comparing their retention times and mass spectra with those of reference compounds. The conditions of both analytical methods were optimized and validated. Sufficient separation of target analytes was achieved using a buffer consisting of 40 mM sodium borate and 60 mM sodium dodecylsulfate (SDS) containing 10% methanol (pH 9.5) at 250 nm for CE analysis and gradient elution with a water-methanol mobile phase and ultraviolet (UV) photodiode array detector (DAD) at 250 nm for HPLC analysis. The mBHT components were determined within 65 min by HPLC and 16 min by CE. All calibration curves showed high linearity (R > 0.999) within the ranges tested. Intra-day and inter-day precision were less than 1.6% and 1.8% for HPLC and 2.5% and 4.8% for CE, respectively. The accuracy of the methods ranged from 98.8% to 102.3% for HPLC and from 95.9% to 108.2% for CE.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.429-432
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• 2000

Chitosan scaffold is widely applied to drug delivery and tissue engineering. We have developed chitosan scaffolds, with various pore size, by differing freezing temperature and duration of ultraviolet (UV) irradiation, for reconstructing skin equivalent. Chitosan scaffold was coated with type I collagen, fibronectin and basic fibroblast growth factor (bFGF) in various combinations and concentrations, to evaluate the effect of extracellular matrix (ECM) and bFGF on cell adhesion, growth and differentiation of dermal fibroblasts. Human dermal fibroblasts, isolated from newborn foreskin and passaged between 3 and 5, were seeded on the top of scaffolds and cultivated for 2 weeks. We examined the morphology and the secretion of ECM of fibroblasts using scanning electron microsopy (SEM) and histochemistry. A stellate morphology of fibroblasts were seen in all groups. The scaffold coated with either type I collagen and bFGF or type I collagen and fibronectin, however, showed the best condtion of dermal fibroblasts, in that the highest cell number and ECM secretion were seen. On the contrary, scaffolds coated with all three factors, type I collagen, bFGF and fibronectin, showed lower number of cells and ECM secretion than scaffolds with two factors. There was a tendency of dose-dependence in all three factors for fibroblast growth and ECM secretion. In conclusion, we may suggest that chitosan scaffold coated with either type I collagen/bFGF or type I collagen/fibronectin could provide more favorable environment for the growth and differentiation of dermal fibroblasts.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.314-320
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• 2014

Three leaf vegetables, namely green lettuce, red lettuce (Lactuca sativa) and red-veined chicory (Cichorium intybus) were grown in minigreenhouses covered with two new functional films and conventional polyethylene film (PE). Seedlings of leaf vegetables were transplanted in a plastic troughs filled with soil-perlite mixture. Two functional films were made from polyolefin (PO) material. Measurement of optical characteristics showed that polyolefin films have better transmittance for the photosynthetic active radiation (PAR, 400-700nm) and higher absorptance for the ultraviolet radiation (UV, 300-400nm) in comparison with the conventional PE film. After three months of utilization higher loss in PAR transmittance was observed for conventional PE film. Leaf vegetables growth was enhanced and yield was increased in greenhouses covered by new functional films.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1201-1207
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• 2016

Background: Excessive exposure to the sun during childhood is strongly associated with the development of skin cancer in the future. The only way to prevent the development of skin cancer is to protect against ultraviolet radiation, which can be achieved through strategic awareness during childhood and adolescence. Objective. The aim of this work was to evaluate the impact of educational activities for rural and urban students to promote the use of sunscreens and prevent skin cancer. Materials and Methods: This study was carried out with students (9-12 years) of rural (n=70) and urban (n=70) schools in Rio Grande do Sul state, Brazil. The educational interventions were lectures and games. The impact of this strategy was evaluated through the application of a questionnaire before and after the interventions. Results: Before the intervention, it was found around 50% of rural and urban students were not aware of the damage caused by sun exposure, often exposing themselves to UV radiation without use sunscreen ( ~ 25 %) and at the most critical times of the day/year. After the lectures we observed an improvement in the behavior of the students with regard to sun exposure and knowledge about skin cancer. Conclusions: The results of this study emphasize the importance of prevention strategies for skin cancer and promoting the use of sunscreens based educational strategies. The interventions were of great value in relation to disseminating knowledge on the subject.