• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.34.2-34.2
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• 2009

The silver sulphide (Ag2S) thin films have been chemically deposited from an alkaline medium (pH 8 to 10) by using a silver nitrate and thiourea as a Ag and S ion precursor sources. Ethylene Damine tetraacetic acid (EDTA) was used as a complexing agent. The effect of annealing atmosphere such as Ar, N2+H2S and O2 on the structural, morphological and optical properties of Ag2S thin films has been studied. The annealed films were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical absorption techniques for the structural, morphological, and optical properties, respectively. XRD studies reveal that the as-deposited thin films are polycrystalline with monoclinic crystal structure, is converted in to silver oxide after air annealing. The surface morphology study shows that grains are uniformly distributed over the entire surface of the substrate. Optical absorption study shows the as-deposited Ag2S thin films with band gap energy of 0.92eV and after air annealing it is found to be 2.25 eV corresponding to silver oxide thin films.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.689-693
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• 2009

Germination is well-known to enhance the digestibility, functionality, and palatability of plant seeds. To examine the functionality of germinated-safflower seed (GSS), proliferative and differentiative effects of GSS extract on the mouse calvarial bone cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolinbromide (MTT) assay and alkaline phosphatase activity, respectively. Water extract of GSS increased dose-dependently proliferative and differentiative effects on calvarial bone cell, and its effects were stronger than those of ungerminated-safflower seeds (UGSS) extract. One major component was isolated from GSS extract by a series of purification procedure of solvent fractionation, Diaion HP-20, and Sephadex LH-20 column chromatographies. Its chemical structure was identified as trachelogenin (TC) by nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectral analysis. Trachelogenin showed significant proliferative (125.7%) and differentiative (132.1%) effects on calvarial bone cells at $10^{-8}M$, and its effects were significantly higher than those of $17{\beta}-estradiol\;(E_2)$. TC was found to be a major active compound responsible for high proliferative and differentative effects of the water extract of GSS. Therefore, these results suggest that TC in GSS may be useful as potential therapeutic agent for the prevention and treatment of bone loss.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1063-1066
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• 2016

Longan (Dimocarpus longan Lour.) has been used as a traditional oriental medicine and possesses a number of physiological activities. In this study, we used cell-based herbal extract screening to identify longan fruit extract (LFE) as an activator of osteoblast differentiation. LFE up-regulated alkaline phosphatase (ALP) activity, induced mineralization, and activated Runx2 gene expression in MC3T3-E1 cells. Furthermore, treatment of MC3T3-E1 cells with LFE promoted the phosphorylation of extracellular signal-regulated kinase1/2 (Erk1/2); however, abrogation of Erk1/2 activation with PD98059 resulted in down-regulation of the phospho-SMAD1/5/8 and Runx2 levels, which in turn reduced the ALP activity. Our findings suggest that LFE exerts its osteogenic activity through activation of the ERK signaling pathway and may have potential as an herbal therapeutic or a preventive agent for the treatment of osteoporosis.

• Molecules and Cells
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• v.43 no.9
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• pp.831-840
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• 2020

The β-class of carbonic anhydrases (β-CAs) are zinc metalloenzymes widely distributed in the fungal kingdom that play essential roles in growth, survival, differentiation, and virulence by catalyzing the reversible interconversion of carbon dioxide (CO₂) and bicarbonate (HCO₃^-). Herein, we report the biochemical and crystallographic characterization of the β-CA CafA from the fungal pathogen Aspergillus fumigatus, the main causative agent of invasive aspergillosis. CafA exhibited apparent in vitro CO₂ hydration activity in neutral to weak alkaline conditions, but little activity at acidic pH. The high-resolution crystal structure of CafA revealed a tetramer comprising a dimer of dimers, in which the catalytic zinc ion is tetrahedrally coordinated by three conserved residues (C119, H175, C178) and an acetate anion presumably acquired from the crystallization solution, indicating a freely accessible "open" conformation. Furthermore, knowledge of the structure of CafA in complex with the potent inhibitor acetazolamide, together with its functional intolerance of nitrate (NO₃^-) ions, could be exploited to develop new antifungal agents for the treatment of invasive aspergillosis.

• Journal of Fashion Business
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• v.9 no.5
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• pp.136-144
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• 2005

Oxidative hair color is currently widely used because of its beautiful light color and good dyeability. In this study, hair color, oxidative agents, and dye intermediate were reacted. Modifier, which changes color with various hue, and alkaline agent, which opens the cuticle of hair fiber and enhances the dyeing reaction, were added. For gel formation, isocetyl alcohol was used as solvent in preparing three kinds of permanent oxidative hair color. Physiochemical study of prepared permanent oxidative hair color was done for basic information acquisition. Acid perspiration test, pH measurement both at room temperature and at high temperature, drop movement test, dyeability efficiency upon the amount of hydrogen peroxide added, and humidity fastness were studied. Shampoo fastness and light fastness of prepared permanent oxidative hair color dyed hair sample were also investigated. All three kinds of hair color prepared showed good properties overall, however, dyed hair sample became reddish upon shampoo fastness and lightfastness tests.

• Journal of Korean Association for Spatial Structures
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• v.23 no.3
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• pp.87-94
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• 2023

Chloride is one of the most common threats to reinforced concrete (RC) durability. Alkaline environment of concrete makes a passive layer on the surface of reinforcement bars that prevents the bar from corrosion. However, when the chloride concentration amount at the reinforcement bar reaches a certain level, deterioration of the passive protection layer occurs, causing corrosion and ultimately reducing the structure's safety and durability. Therefore, understanding the chloride diffusion and its prediction are important to evaluate the safety and durability of RC structure. In this study, the chloride diffusion coefficient is predicted by machine learning techniques. Various machine learning techniques such as multiple linear regression, decision tree, random forest, support vector machine, artificial neural networks, extreme gradient boosting annd k-nearest neighbor were used and accuracy of there models were compared. In order to evaluate the accuracy, root mean square error (RMSE), mean square error (MSE), mean absolute error (MAE) and coefficient of determination (R2) were used as prediction performance indices. The k-fold cross-validation procedure was used to estimate the performance of machine learning models when making predictions on data not used during training. Grid search was applied to hyperparameter optimization. It has been shown from numerical simulation that ensemble learning methods such as random forest and extreme gradient boosting successfully predicted the chloride diffusion coefficient and artificial neural networks also provided accurate result.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.1
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• pp.57-64
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• 2011

Purpose: The purpose of this study was to compare the cleansing performance of a distilled water, a diluted solution of sodium hypochlorite as a household bleaching cleanser and three alkaline peroxide cleansers in vivo plaque deposits by using scanning electron microscope. Materials and methods: Five individuals were selected from department of the prosthodontics in Pusan National University Hospital, and each of them was inserted with specimens for plaque accumulation in their temporary dentures for 48 hours. The specimens were removed and cleaned by each cleansing agents for 8 hours. Scanning electron micrographs were made from the specimens at a magnification of ${\times}2,000$. A panel of ten persons with a dental or paradental background, but not directly involved in the study, was selected to analyze the photomicrographs to determine which denture cleanser was more effective in removing plaque. Results: Diluted solution of sodium hypochlorite was the most effective at removing plaque following $Polident^{(R)}$, $Cleadent^{(R)}e$, $Bonyplus^{(R)}$ and distilled water in order. But there was no significant difference of cleansing efficacy between diluted solution of sodium hypochlorite and $Polident^{(R)}$, $Polident^{(R)}$ and $Cleadent^{(R)}e$, $Cleadent^{(R)}e$ and $Bonyplus^{(R)}$, respectively (P > .05). Alkaline peroxide cleansers by themselves cannot adequately remove accumulated plaque deposits, especially if the deposits are heavy. Corrosion could be seen on the surface of non-precious alloy specimens immersed in diluted solution of sodium hypochlorite. Conclusion: It is recommended to use of alkaline peroxide type cleansers with brushing whenever possible, since denture cleanliness is often poor due to the relative inefficiency of these cleansers.

• Journal of Periodontal and Implant Science
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• v.29 no.4
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• pp.765-785
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• 1999

Bone morphogenetic protein-2/4 (BMP-2/4) are members of Transforming Growth $Factor-{\beta}\;(TGF-{\beta})$ superfamily and they may differentiate the osteoprogenitor cell and induce formation of cartilage and bone in vivo. This study was performed to investigate the effects of bone morphogenetic protein-2/4 on the characteristics of rat periodontal ligament cells(RPDL) and rat calvaria cells(RCV). In the control group, the cells were cultured alone with Dulbeco's Modified Eagle's Medium contained with 20% fetal bovine serum, $100{\mu}/ml$ penicillin, $100{\mu}/ml$ streptomycin. In the experimental groups, recombinant human bone morphogenetic protein-2/4 (25ng, 100ng, 250ng/ml) were added into the above culture condition. And then each group was characterized by examing the cell proliferation at 1, 2, 3, 5, 7th day, the amount of total protein synthesis and alkaline phosphatase activity at 2, 5, 7th day. And also, the calcified nodule was examed. The results were as follows ; 1 . Both RCV and RPDL cells in both control and experimental groups proliferated during the entire experimental period, but there is no stastically significant difference according to the BMP-2/4 concentration. 2 . Amount of total protein synthesis of both cells in both groups was steadily increased until 5th day, but all experimental groups were significantly different from the control group at 7th day. 3. Alkaline phosphatase activity of both cells in both groups was increased during the entire experiment period. In RCV cells, the experimental group treated with 100ng/ml and 250ng/ml BMP-2/4 were significantly different from the control group at 7th day. In RPDL cells, the experimental group treated with 100ng/ml and 250ng/ml BMP-2/4 were significantly different from the control group at 5th day, and all experimental groups were significantly different from the control group at 7th day. 4. In the both of the cultured Rat Periodontal ligament and calvaria cell treated with BMP-2/4 to compared with control group, it revealed more rapid cell polarization, cell aggregation and hyperchromatic stained on HE agent, and even though only 1 day treated with BMP-2/4 both RPDL and RCV showed more rapid cell reaction than control group. More sensivitve cell reaction of RCV were observed than RPDL in this experiment. From the above results, we could conclude that BMP-2/4 influenced the induction, proliferation and differentiation of bone forming cells

• Journal of Life Science
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• v.12 no.2
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• pp.136-143
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• 2002

Jaboyangyeong-hwan (IAE) has been known as a traditional medicine for the treatment of debility, fatigue, and liver diseases. The hepatoprotective effect of the water extract of Jaboyangyeong-hwan was investigated against carbon tetrachloride ($CCl_4$)-induced hepatic damage. A single intraperitoneal injection of $CCl_4$produced liver damage in rats as manifested by the significant rise of aspartate aminotransferase (AST, alanine aminotransferase (ALT), and alkaline phosphatase (ALP) in serum as compared to those of untreated normal group. Pretreatments of rats with the JAE extract (300, 600, and 1200 mg/kg for 7 days) were significantly reduced AST, ALT, and ALP levels compared with $CCl_4$-treated control group. Treatment of rats with $CCl_4$led to significantly increase in lipid peroxidation and significantly decrease in cytochrome P450 and P450 reductase. The oral administration of the JAE extract significantly inhibited the accumulation of microsomal thiobarbituric acid reactive substance (TBARS) and increased the cytochrome P450 and P450 reductase activity. All these biochemical alterations resulting from $CCl_4$administration were inhibited by the pretreatment with JAE extract. These results suggest that JAE water extract can be useful as a hepatoprotective agent.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.154-159
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• 2009

The hepatoprotective effect of ethanol extract from Hovenia dulcis fruit (HD) against ethanol-induced oxidative damage was investigated. Ethanol-induced reactive oxygen species (ROS) generation and liver damage on HepG2/2E1 cells were protected by $100{\mu}g/mL$ ethanolic extract from HD. Male C57BL/6 mice were divided into 3 groups; control (NC), ethanol (ET), ethanol plus 1 g/kg body weight ethanolic extract of HD (ET-HD). The activities of serum alanine amintransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were significantly increased in ethanol-treated group. However, ET-HD group showed protective effect by lowering serum activities. The ET group markedly decreased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione-s-transferase (GST) with the reduced level of glutathione (GSH) in liver. On the other hand, ET-HD group increased the activities of SOD and GST, and the level of GSH. Lipid peroxidation level, which was increased after ethanol administration, was significantly reduced in ET-HD group. Based upon these results, it could be assumed that ethanolic extract of HD protected the liver against ethanol-induced oxidative damage by possibly inhibiting the suppression of antioxidant activity and reducing the rate of lipid peroxidation in vitro and in vivo. Therefore, extract of Hovenia dulcis fruit might be used as a protective agent for ethanol-induced hepatic damages.