• The Journal of Korean Medicine
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• v.30 no.5
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• pp.26-41
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• 2009

Objectives: The experiment was to estimate the value of Saengmaegsan as a therapeutic anti-aging agent with an analysis of ingredients and their bio-activating effects by enzymologic methods. Methods: We analyzed anti-aging effects of the ingredients of Saengmaegsan being Liriope Platyphylla, Schizandrae Chinensis, and Schizandrae Chinensis. Results: In Liriope Platyphylla and Schizandrae Chinensis, reducing sugar concentration was shown at the highest level. Of mineral contents, K+ and Na+ were the highest in Saengmaegsan and each ingredient also, and then Ca++ and Al. The amount of polyphenol showed was in order Schizandrae Chinensis > Saengmaegsan > Panax Ginseng > Liriope Platyphylla. The electron donating ability of Schizandrae Chinensis doubled that of Saengmaegsan and Panax Ginseng, at the same time that one per 1 ml in Saengmaegsan was significantly found the greatest level as compared to each single ingredient. SOD-like activity was high in Saengmaegsan and Schizandrae Chinensis. SOD-like activity of Saengmaegsan was higher than in single components. Nitric oxide inhibition in pH 1.2 was high in Saengmaegsan and Schizandrae Chinensis, and for per 1 ml it showed the same pattern as above. In pH 3.0 the result was not different from in pH 1.2. Xanthine oxidase inhibition was high in Schizandrae Chinensis and for per 1 ml showed the greatest activity in Liriope Platyphylla. Tyrosinase inhibition in Omija was the most noticeable, and for per 1 ml was Liriope Platyphylla more than any others. Conclusions: With this analysis of ingredients, it is proven that Saengmaegsan and each component fosters antioxidation. On the whole, the composite prescription Saengmaegsan was superior to each individual component.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.434-436
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• 2007

In the previous study, we reported the inhibitory effects of Rodgersia podophylla root extract on tyrosinase activity and melanin production in melan-a cells. However, mechanism of the inhibitory activity and in vivo assay were not yet examined. This study performed the examination of the effects of Rodgersia podophylla root extract on protein expression and in vivo depigmenting activity using melan-a cells and brown guinea pigs. As the results of western immunoblotting analysis, treatment of Rodgersia podophylla root extract reduced tyrosinase expression rates in 10 and 100 ppm concentrations, dose dependently. Moreover, Rodgersia podophylla root extract exhibited depigmenting activity on UV-B induced hyperpigmentation in brown guinea pig skin. These results suggested that Rodgersia podophylla root extract could act as whitening agent for the skin via not only direct tyrosinase activity inhibition but also reducing of tyrosinase expression.

• Advances in nano research
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• v.15 no.1
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• pp.1-13
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• 2023

Ti₃C₂T_x MXene, a 2D material, is known to exhibit unique characteristics that are strongly dependent on surface termination groups. Here, we developed a novel annealing approach with Ca as a reducing agent to simultaneously remove F and O groups from the surface of multilayered MXene powder. Unlike H₂ annealing that removes F effectively but has difficulty in removing O, annealing with Ca effectively removed both O and F. X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy revealed that the proposed approach effectively removed F and O from the MXene powder. The results of O/N analyses showed that the O concentration decreased by 57.5% (from 2.66 to 1.13 wt%). In addition, XPS fitting showed that the volume fraction of metal oxides (TiO₂ and Al₂O₃) decreased, while surface termination groups (-O and -OH) were enhanced, which could increase the hydrophilic and adsorption properties of the MXene. These findings suggest that when F and O are removed from the MXene powder, the interlayer spacing of its lattice structure increases. The proposed treatment also resulted in an increase in the specific surface area (from 5.17 to 10.98 m²/g), with an increase in oxidation resistance temperature in air from ~436 to ~667 ℃. The benefits of this novel technology were verified by demonstrating the significantly improved cyclic charge-discharge characteristics of a lithium-ion battery with a Ca-treated MXene electrode.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.35-42
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• 2006

Experimental study was conducted to identify the active agent for reductive dechlorination of TCE in cement/Fe(II) systems. Several potential materials-hematite (${\alpha}-Fe_2O_3$), lepidocrocite (${\gamma}$-FeOOH), akaganeite (${\beta}$-FeOOH), ettringite ($Ca_6Al_2(SO_4)_3(OH)_{12}$)-that are cement components or parts of cement hydrates were tested if they could act as reducing agents by conducting TCE degradation experiments. From the initial degradation experiments, hematite was selected as a potential active agent. The pseudo-first-order degradation rate constant ($k\;=\;0.637\;day^{-1}$) for the system containing 200 mM Fe(II), hematite and CaO was close to that ($k\;=\;0.645\;day^{-1}$) obtained from the system containing cement and 200 mM Fe(II). CaO, which was originally added to simulate pH of the cement/Fe(II) system, was found to play an important role in degradation reactions. The reactivity of the hematite/CaO/Fe(II) system initially increased with increase of CaO dosage. However, the tendency declined in the higher CaO dosage region, implying a saturation type of behavior. The SEM analysis revealed that the hexagonal plane-shaped crystals were formed during the reaction with increasing degradation efficiency, which was brought about by increasing the CaO dosage. It was suspected that the crystals could be portlandite or green rust ($SO_4$) or Friedel's salt. The XRD analysis of the same sample identified the peaks of hematite, magnetite/maghemite, green rust ($SO_4$). Either instrumental analysis predicted the presence of the green rust ($SO_4$). Therefore, the green rust ($SO_4$) would potentially be a reactive agent for reductive dechlorination in cement/Fe(II) systems.

• Journal of Periodontal and Implant Science
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• v.30 no.3
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• pp.661-676
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• 2000

Gingivitis and periodontitis are infectious diseases in that microorganisms are the primary extrinsic cause of the diseases. the occurrence of gingivitis has been associated clearly with the presence of microorganisms at the disease site, and the histologic nature of the tissue involved is indicative of an inflammatory response induced by microorganisms. additional evidence for the microbial etiology of periodontal disease is that numerous antimicrobial agents are effective in reducing plaque accumulation and periodontal diseases. the purpose of this article is to analyze the antimicrobial effects of Pulsatilla koreana. Well-dried Pulsatilla koreana purchased from herbs distributor was ground and extracted into methanol(MeOH), ethylacetate(EtoAc), chlorform($CHCl_3$) and Butyl alcohol(BuOH). we have then applied each solution to the bacteria samples(Bacteroides forsythus, Streptococcus mutans, Streptococcus sanguis, Porphylomonas gingivalis, Actinobacillus actinomycetemcomitans, Eikenella corrodens, Prevotella intermedia, Actinomyces viscosus, Prevotella nigrescens , Rothia dentocariosa, Fusobacterium nucleatum, Pseudomonas aeruginosa, Staphylococcus aureus) collected from several organizations. To conduct susceptibility test(Kirby-Bauer method), plate contained each periodontopathic bacteria is spread extracted into methanol(MeOH), ethylacetate(EtoAc), chlorform($CHCl_3$) and Butyl alcohol(BuOH) and to measure the minimum inhibition concentration(MIC) of the bacteria against the solutions to ultimately determine antimicrobial effects of the solutions, insert bacteria sample into $20{\mu\ell}/{m\ell}$, $10{\mu\ell}/{m\ell}$, $5{\mu\ell}/{m\ell}$, $2.5{\mu\ell}/{m\ell}$ of each solution and control group(not contained solution) 1. Solution extracted into methanol did not show clear zone against all bacteria samples. Only P.nigrescens, S. mutans and S. sanguis in solution extracted into ethylacetate, S. mutans and S. anguis in solutions extracted into chlorform and Butyl alcohol showed clear zone against all bacteria samples. Solution extracted into Butyl alcohol showed clear zone against 13 types of bacteria, excluding P. gingivalis. 2. In Solution extracted into methanol, the bacteria samples grew in the highest concentrated plate, showing minimal variation from control group. 3. In Solution extracted into Butyl alcohol, S. aureus, P. intermedia, E. corrodens, A. actinomycetemcomitans, B. forsythus, P. gingivalis et al. showed decreased growth in the highest concentrated plate. P. auruginosa, R. dentocariosa, A. viscosus, P. nigrescens, S. mutans et al. showed decreased growth at MIC $20{\mu\ell}/{m\ell}$ and S. sanguis showed decreased growth at MIC $10{\mu\ell}/{m\ell}$. 4. By analyzing the MIC level through considering the results from Kirby-Bauer method, Solution extracted into methanol did not reveal any antimicrobial effects and Solution extracted into Butyl alcohol showed the highest antimicrobial effects In conclusion, it can be used the extracts of Pulsatilla koreana as wide spectrum antimicrobial agent.

• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.103-111
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• 2018

A plasma-catalytic combined process was used as an attempt to improve the conversion efficiency of nitrogen oxides ($NO_x$) over a wide temperature range ($150{\sim}500^{\circ}C$) to cope with the exhaust gas whose temperature varies greatly. Since the catalytic $NO_x$ reduction is effective at high temperatures where the activity of the catalyst itself is high, the $NO_x$ reduction was carried out without plasma generation in the high temperature region. On the other hand, in the low temperature region, the plasma was created in the catalyst bed to make up for the decreased catalytic activity, thereby increasing the $NO_x$ conversion efficiency. Effects of the types of catalysts, the reaction temperature, the concentration of the reducing agent (n-heptane), and the energy density on $NO_x$ conversion efficiency were examined. As a result of comparative analysis of various catalysts, the catalytic $NO_x$ conversion efficiency in the high temperature region was the highest in the case of the $Ag-Zn/{\gamma}-Al_2O_3$ catalyst of more than 90%. In the low temperature region, $NO_x$ was hardly removed by the hydrocarbon selective reduction process, but when the plasma was generated in the catalyst bed, the $NO_x$ conversion sharply increased to about 90%. The $NO_x$ conversion can be maintained high at temperatures of $150{\sim}500^{\circ}C$ by the combination of plasma in accordance with the temperature change of the exhaust gas.

• Clean Technology
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• v.16 no.4
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• pp.284-291
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• 2010

Nitrous oxide ($N_2O$) is a greenhouse material which is hard to remove. Even with a catalytic process it requires a reaction temperature, at least, higher than 670 K. This study has been performed to see the effects of Ce addition to the mixed oxide catalyst which shows the highest activity in decomposing $N_2O$ completely at temperature as low as 473 K when CO is used as a reducing agent. Mixed metal oxide(MMO) catalyst was made through co-precipitation process with small amount of Ce added to the base components of Co, Al and Rh or Pd. Consequently, the surface area of the catalyst decreased with the contents of Ce, and the catalytic activity of direct decomposition of $N_2O$ also decreased. However, in the presence of CO, the activity was found high enough to compensate the portion of activity decrease by Ce addition, so that it can be ascertained that the catalytic activity and stability can be maintained in the CO involved $N_2O$ reduction system when Ce is added for the physical stability of the catalyst.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.92-100
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• 2016

Low-temperature conversion of nitrogen oxides using plasma-assisted hydrocarbon selective catalytic reduction of (HC-SCR) was investigated. Plasma was created in the catalyst-packed bed so that it could directly interact with the catalyst. The effect of the reaction temperature, the shape of catalyst, the concentration of n-heptane as a reducing agent, the oxygen content, the water vapor content and the energy density on $NO_x$ removal was examined. $NO_x$ conversion efficiencies achieved with the plasma-catalytic hybrid process at a temperature of $250^{\circ}C$ and an specific energy input (SIE) of $42J\;L^{-1}$ were 83% and 69% for one-dimensional Ag catalyst ($Ag\;(nanowire)/{\gamma}-Al_2O_3$) and spherical Ag catalyst ($Ag\;(sphere)/{\gamma}-Al_2O_3$), respectively, whereas that obtained with the catalyst-alone was considerably lower (about 30%) even with $Ag\;(nanowire)/{\gamma}-Al_2O_3$ under the same condition. The enhanced catalytic activity towards $NO_x$ conversion in the presence of plasma can be explained by the formation of more reactive $NO_2$ species and partially oxidized hydrocarbon intermediates from the oxidation of NO and n-heptane under plasma discharge. Increasing the SIE tended to improve $NO_x$ conversion efficiency, and so did the increase in the n-heptane concentration; however, a further increase in the n-heptane concentration beyond $C_1/NO_x$ ratio of 5 did not improve the $NO_x$ conversion efficiency any more. The increase in the humidity affected negatively the $NO_x$ conversion efficiency, resulting in lowering the $NO_x$ conversion efficiency at the higher water vapor content, because water molecules competed with $NO_x$ species for the same active site. The $NO_x$ conversion efficiency increased with increasing the oxygen content from 3 to 15%, in particular at low SIE values, because the formation of $NO_2$ and partially oxidized hydrocarbon intermediates was facilitated.

• Journal of the Korean Institute of Gas
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• v.19 no.5
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• pp.20-28
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• 2015

This work investigated the size and shape effect of ${\gamma}$-alumina-supported metal oxides on the hydrocarbon selective catalytic reduction of nitrogen oxides. Several metal oxides including Ag, Cu and Ru were used as the catalysts, and n-heptane as the reducing agent. For the Ag/${\gamma}$-alumina catalyst, the $NO_x$ reduction efficiency in the range of $250{\sim}400^{\circ}C$ increased as the size of Ag decreased (20 nm>50 nm>80 nm). The shape effect of metal oxides on the $NO_x$ reduction was examined with spherical- and wire-shape nanoparticles. Under identical condition, higher catalytic activity for $NO_x$ reduction was observed with Ag and Cu wires than with the spheres, while spherical- and wire-shape Ru exhibited similar $NO_x$ reduction efficiency to each other. Among the metal oxides examined, the best catalytic activity for $NO_x$ reduction was obtained with Ag wire, showing almost complete $NO_x$ removal at a temperature of $300^{\circ}C$. For Cu and Ru catalysts, considerable amount of NO was oxidized to $NO_2$, rather than reduced to $N_2$, leading to lower $NO_x$ reduction efficiency.

• Clean Technology
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• v.26 no.2
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• pp.145-150
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• 2020

Nitrous oxide (N₂O) is one of the six greenhouse gases, and it is essential to reduce N₂O by showing a global warming potential (GWP) equivalent to 310 times that of carbon dioxide (CO₂). Selective catalytic reduction (SCR) is a technology that converts ammonia into harmless N₂ and H₂O by using ammonia as a reducing agent to remove NOx, one of the air pollutants; the process also produces high denitrification efficiency. In this study, the Fe-BEA catalyst was steam-treated at 100 ℃ for 2 h before Fe ion exchange in the fixed bed reactor in order to investigate the effect of the steam-treated Fe-BEA catalyst on the NH₃-SCR reaction. NH₃-SCR reaction test of synthesized catalysts was performed at WHSV = 180 h^-1, 370 to 400 ℃ in the fixed bed reactor. The Fe-BEA(100) catalyst steam-treated at 100 ℃ showed a somewhat higher activity than the Fe-BEA catalyst at 370 to 390 ℃. The catalysts were characterized by BET, ICP, NH₃-TPD, H₂-TPR, and ²⁷Al MAS NMR in order to determine the cause affecting NH₃-SCR activity. The H₂-TPR result confirmed that the Fe-BEA(100) catalyst had a higher reduction of isolated Fe³⁺ than the Fe-BEA catalyst, and that the steam treatment increased the amount of isolated Fe³⁺ as an active species, thus increasing the activity.