• Biomedical Science Letters
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• v.8 no.4
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• pp.229-234
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• 2002

Chlorella is rich in chlorella growth factor (CGF). A review of the literature has described that CGF improves the capability of a Th1-based immunity, anticancer, antioxidant antibacterial activity, growth promotion, wound healing and so on, but has not studied the effect for the metabolism and the proliferation of human skin keratinocyte. The aim of this study was to examine the effect of metabolism and the proliferation of human skin keratinocyte in vitro. CGF was extracted with an autoclaving method which is a modified hot-water extraction method from dried chlorella and conformed by means of absorbance 0.22 at 260 nm. We have measured the extracellular acidification rate (ECAR) of the CGF by Cytosensor$^{\circledR}$ Microphysiometer and evaluated responsiveness depending upon the dosage on the HaCaT cell. The ECAR for the concentrations of 0.15, 1.5, 15, 150 $\mu\textrm{g}$/ml of CGF increased as a 103.6, 128.2, 149.0 and 423.9%, respectively compared to control (0.0 $\mu\textrm{g}$/ml, 100% ECAR). The ECAR for ErbBl tyrosine kinase inhibited by 4-anilinoquinazolines, $C_{16}$H$_{14}$BrN$_3$O$_2$.HCl on tile HaCaT cells with the amounts of 10 $\mu\textrm{g}$/ml of the CCF compared with 100 $\mu\textrm{g}$/ml of rhEGF. The conclusion of the study is that CGF might increase human epidermal keratinocyte proliferation through the interaction between the epidermal growth factor receptor and itself.

• Biomedical Science Letters
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• v.9 no.1
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• pp.51-58
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• 2003

This study was carried out to investigate the preventive and therapeutic effect of Panax ginseng water extract (PG-WE) on the toxicity induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), one of the most notorious toxic environmental pollutants belonging to the group of polyhalogenated aromatic hydrocarbons. Normal control (NC) group guinea pigs (180~200 g) received vehicle and saline, and TCDD-treated (TT) group was given TCDD and saline. P100 and P200 group animals received PG-WE for 28 days since 1 week before TCDD exposure at daily doses of 100 mg/kg b.w. and/or 200 mg/kg b.w., respectively. C100 and C200 group received PG-WE for 14 days starting 1 week after TCDD-exposure. Toxicity was induced by a single intraperitoneal injection of TCDD (1 $\mu\textrm{g}$/kg b.w.). Abnormal increase in AST and ALT activities in TT group was significantly improved by the administration of PC-WE. Microscopically, there were mild to moderate swelling of hepatocytes, hyperchromatism of individual cells, acidophilic cytoplasm and cytoplasm vacuolation of some hepatocytes, slight to moderate variations of staining density, occasional single cell necrosis, variable size and shape of some hepatocytes, small groups of degenerating hepatocytes surrounded by mononuclear cells, dilated sinusoids of centrilobular zone and some loss of lobular architecture in TT group liver. From these results, we could find the protective and therapeutic role of PG-WE in TCDD-induced liver toxicity by examining the blood chemical parameters and histopathological observation.

• Korean Journal of Medicinal Crop Science
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• v.18 no.2
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• pp.118-125
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• 2010

This study was carried out to determine changes in general chemical composition, free sugars, physicochemical properties of extract, and ginsenoside contents depending upon processing methods. Ginseng roots harvested from the same field were employed for the processing into white ginseng (WG), taegeuk ginseng (TG), red ginseng A (RGA, steamed one time), and red ginseng B (RGB, steamed three times). The fat content decreased by increasing duration of treatment and number of steaming treatment. On the other hand, there was no significant variation in contents of ash and carbohydrate depending on processing methods. Contents of sucrose and maltose was higher in Taegeuk and red ginseng than those of white ginseng. Steamed ginseng root (taegeuk and red ginseng root) showed higher amount of water extractable solid than the unsteamed white ginseng, but the variation of crude saponin content was not distinctive depending on processing methods. The contents of total ginsenosides increased by the order of white, taegeuk, red A, and red B root. In summary, chemical composition and total ginsenoside content were different according to part of root and processing methods, thus implies the importance of quality control as well as pharmacological activity of ginseng root.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.207.1-207.1
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• 2014

High-mobility and two dimensional conduction at the interface between two band insulators, LaAlO3 (LAO) and SrTiO3 (STO), have attracted considerable research interest for both applications and fundamental understanding. Several groups have reported the photoconductivity of LAO/STO, which give us lots of potential development of optoelectronic applications using the oxide interface. Recently, a giant photo response of Pd nano particles/LAO/STO is observed in UV illumination compared with LAO/STO sample. These phenomena have been suggested that the correlation between the interface and the surface states significantly affect local charge modification and resulting electrical transport. Water and gas adsorption/desorption can alter the band alignment and surface workfunction. Therefore, characterizing and manipulating the electric charges in these materials (electrons and ions) are crucial for investigating the physics of metal oxide. Proposed mechanism do not well explain the experimental data in various ambient and there has been no quantitative work to confirm these mechanism. Here, we have investigated UV photo response in various ambient by performing transport and Kelvin probe force microscopy measurements simultaneously. We found that Pd nano particles on LAO can form Schottky contact, it cause interface carrier density and characteristics of persistence photo conductance depending on gas environment. Our studies will help to improve our understanding on the intriguing physical properties providing an important role in many enhanced light sensing and gas sensing applications as a catalytic material in different kinds of metal oxide systems.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.412-412
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• 2014

Zinc oxide (ZnO) is one of the most powerful materials for purifying organic pollutants using photocatalytic activity. In this study, we have introduced a novel method to design highly photoreactive flexible 3 dimensional (3D) ZnO nanocomposite [F-ZnO-m (m: reaction time, min)] by electrospinning and simple-step ZnO growth processing (one-step ZnO seed coating/growth processing). Significantly, the F-ZnO-m could be a new platform (or candidate) as a photocatalytic technology for both morphology control and large-area production. The highest photocatalytic degradation rate ([k]) was observed for F-ZnO-m at 2.552 h-1, which was 8.1 times higher than that of ZnO nanoparticles (NPs; [k] = 0.316 h-1). The enhanced photocatalytic activity of F-ZnO-m may be attributed to factors such as large surface area. The F-ZnO-m is highly recyclable and retained 98.6% of the initial decolorization rate after fifteen cycles. Interestingly, the F-ZnO-m samples show very strong antibacterial properties against both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) after exposure to UV-light for 30 min. The antibacterial properties of F-ZnO-m samples are more effective than those of ZnO NPs. More than 96.6% of the E. coli is sterilized after ten cycles. These results indicate that F-ZnO-m samples might have utility in several promising applications such as highly efficient water/air treatment and inactivation of pathogenic microorganisms.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.471-478
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• 2012

The objective of the study is to find a way to utilize MSWI slag as filter material and to verify it. To do so, stability as filter material was tested, and used Ju-Munjin filter sand as control group to run actual filtering experiment to analyze filtering efficiency. According to result, MSWI slag is usable within designated waste acceptable standards. Also, it showed similar level of filtering capability to filter sand. Thus, MSWI slag could help to save and recycle resources if used as filtering material instead of filter sand As result of filtering test, SS and COD showed about same level of filtering capability similar to standard filter sand. MSWI slag has shown 26.96% higher with T-N, and 6.55% higher with T-P compared to standard filter sand. Also, remove efficiency comparison result with No. 40#(0.43mm) and mixed diameter showed equal or greater filtering capability.

• Korean Journal of Materials Research
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• v.21 no.8
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• pp.444-449
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• 2011

Nano-sized $Y_2O_3$ powders were prepared via a sol-gel method starting with $Y(NO_3)_3{\cdot}6H_2O$ (Yttrium(III) nitrate hexahydrate) and water with ethanol as a cosolvent. $Y_2O_3$ is an important rare earth oxide and has been considered for use in nuclear applications, such as ceramic materials, due to its excellent optical and refractory characteristics. It has been used as a chemically stable substrate, a crucible material for melting reactive metals, and a nozzle material for jet casting molten rare earth-iron magnetic alloys. Oxalic acid ($C_2H_2O_4$) has been adopted as a chelating agent in order to control the rate of hydrolysis and polycondensation, and ammonia was added in order to adjust the base condition. The synthesized $Y_2O_3$ powder was characterized using TG/DTA, XRD, FE-SEM, BET and Impedance Analyzer analyses. The powder changed its properties in accordance with the pH conditions of the catalyst. As the pH increases according to the FE-SEM, the grain grew and it showed that the pore size decreased while confirming the effect of the grain size. The nano-material $Y_2O_3$ powders demonstrated that the surface area was improved with the addition of oxalic acid with ammonium hydroxide.

• The Korean Journal of Mycology
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• v.8 no.1
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• pp.7-11
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• 1980

To increase production of Tricholoma matsutake, experiments were carried out in a mountain located in Keumma 2-ri, Joocheon-myun, Yongwol-gun, Kangwon-do, Korea during the period from April to November 1979. The area of the experiment showed pH 6.55 of soil acidity and the rock was found to be granite. Among its vegetation, the major growths were Pinus densiflora Siebold et Zuccarini, Rhododendron mucronulatum Turcz., Rhododendron schlippenhachii Max., Lespedeza bicolor and Pteridium aquilinum (Linne) Kuhn var. japonicum Nakai. Of two equally divided areas of A and B in which pine mushrooms grew, artificial methods such as thinning the upper portion of land raking and water-spraying were applied to area B only, where 21% increase of the production was obtained as compared with the control area A.

• Polymer(Korea)
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• v.24 no.6
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• pp.869-876
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• 2000

In order to improve the cell-compatability of poly(L-lactide-co-glycolide) (75 : 25 by mole ratio of lactide to glycolide, PLGA) surfaces, the physicochemical treatments have been demonstrated. Chemical treatments were 70% perchloric acid. 50% sulfuric acid and 0.5 N sodium hydroxide solution and physical methods were corona and plasma treatment. The water contact angle of surface treated PLGA decreased from 73$^{\circ}$ to 50~60$^{\circ}$, i.e., increased hydrophilicity, due to the introduction of oxygen-containing functional group onto PLGA backbone by the measurement of an electron spectroscopy for chemical analysis. It could be observed that the adhesion and growth of fibroblast cell on physicochemically treated PLGA surfaces, especially perchloric acid treated PLGA surface, were more active than on the controt. In conclusion, it seems that surface wettability as hydrophilicity of PLGA plays an important role in cell adhesion, spreading and growth.

• Membrane Journal
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• v.30 no.5
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• pp.342-349
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• 2020

In this study, we suggest conditions to reduce fouling in capacitive deionization (CDI) caused by alginic acid sodium salt, one of the most common fouling-causing substances in natural water and wastewater management. First, NaCl is used as feed material, which is selected as the control of the experiment. As expected, fouling phenomena is not observed from NaCl. On the other hand, when alginic acid sodium salt is added to the inlet, the fouling phenomena can be observed. In order to minimize the fouling phenomena, the feed concentration of alginic acid sodium salt, applied potential during desorption process, and duration of applied potential to our CDI cell are controlled. With 7 mg/L of feed stream concentration, CDI performed using 1.2 V for 1 min during adsorption followed by desorption with -2 V for 1 min exhibited the highest alginic acid salt removal efficiency reaching 50.07%.