• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.574-581
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• 2022

Nanofibers comprising reduced graphene oxide (rGO) and Mo₂C/Mo₂N nanoparticles (Mo₂C/Mo₂N rGO NFs) were prepared for a functional interlayer of Li-S batteries (LSBs). The well-dispersed Mo₂C and Mo₂N nanoparticles in the nanofiber structure served as active polar sites for efficient immobilization of dissolved lithium polysulfide. The rGO nanosheets in the structure also provide conductive channels for fast ion/electron transport during charging-discharging and ensured reuse of lithium polysulfide during redox reactions through a fast charge transfer process. As a result, the cell assembled with Mo₂C/Mo₂N rGO NFs-coated separator and pure sulfur electrode (70 wt% of sulfur content and 2.1 mg cm^-2 of sulfur loading) showed a stable discharge capacity of 476 mA h g^-1 after 400 charge-discharge cycles at 0.1 C. Furthermore, it exhibited a discharge capacity of 574 mA h g^-1 even at a high current density of 1.0 C. Therefore, we believe that the proposed unique nanostructure synthesis strategy could provide new insights into the development of sustainable and highly conductive polar materials as functional interlayers for high performance LSBs.

• Korean Journal of Medicinal Crop Science
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• v.10 no.5
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• pp.392-398
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• 2002

Comparative analysis of paeoniflorin, albiflorin and phenolic compound contents as bioactive components of peony was performed by Reverse Phase-High Performance Liquid Chromatography (RPHPLC) using the four- year-old peony which were different plant parts and pretreatment, such as removing or unremoving the cork layer of peony root before drying. The contents of paeoniflorin, albiflorin, (+)-taxifolin $3-O-{\beta}-D-glucopyranoside$, (+)-catechin and (-)-epicatechin were the highest in rhizome part, but those of gallic acid and benzoic acid in the leaves were higher than other parts. The contents of albiflorin, gallic acid, benzoic acid and (-)-epicatechin in the cork layer were higher than in those of the core, but the contents of paeoniflorin, (+)-taxifolin $3-O-{\beta}-D-glucopyranoside$ and (+)-catechin in the core were higher than those in the cork layer. In general, the rhizome part of peony root has been used only propagation purpose, but this part contained high contents of bioactive component. Therefore, it is needed that medicinal application of rhizome part in peony root was firmly investigated. Also, In the use of peony root for medicinal purpose, the use of peony root with cork layer can be efficient way on the practical use of useful components and the reduction of labor for removing the cork layer.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.2
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• pp.207-211
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• 1999

$Si/Si_{1-x}Ge_x$ MODFET structures, incorporating linearly-graded buffer layers have been grown by GaS Source Molecular Beam Epitaxy. The growth temperature of the graded layers has not significantly changed the distribution of misfit dislocation. However, the surface undulation and surface defects were increased with increasing growth temperature. In $Si/Si_{1-x}Ge_x$ MODFET structures, the densities of misfit dislocations near the Si-active layers were considerably reduced in comparison with the region of graded layers. The electron mobility of $Si/Si_{1-x}Ge_x$ MODFET structure has increased with lowering the growth temperature.

• Korean journal of food and cookery science
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• v.15 no.3
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• pp.231-237
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• 1999

The anticancer effect of the bark of Broussonetia kazinoki root extracts (hexane. chloroform, ethylacetate, butanol, aqueous) were studied. The cytotoxicity by MTT assay and inhibitory effect on the growth of sarcoma 180 cells were tested in vitro. The reduction rate of the tumor formation and spleen/body weight rate on BALB/c mouse were tested in vivo. From the tests, each fraction showed the cytotoxic effect against the sarcoma 180 cells. In addition, as the concentration of the fractions increased, cytotoxic effect tendency increased as well. The cytotoxic rate of the hexane, chloroform, ethylacetate, butanol and aqueous fractions showed by 58.7%, 40.1%, 75.7%, 52.6% and 62.7% respectively after testing by MTT assay system. And sarcoma 180 cells were incubated for 6 days at 37$^{\circ}C$ with various concentrations of each fraction. As the incubation days go on, the number of cells increased, while the inhibition rate on the growth of sarcoma 180 cells were decreased. Especially the ethylacetate fraction at the concentration of 1.0 mg/ml strongly inhibited the growth of sarcoma 180 cells by 74% compared with the control for a day 37$^{\circ}C$ The hexane, chloroform, ethylacetate, butanol and aqueous fractions inhibited on the growth of sarcoma 180 cells by 31%, 19%, 60%, 30% and 42% respectively, when sarcoma 180 cells has been incubated for 6 days at 37$^{\circ}C$. The each fraction exhibited the antitumor effect in vivo. The ethylacetate fraction reduced the tumor formation by 41% compared with the control, when sarcoma 180 cells were injected subcutaneously into the left groin of BALB/c mice. Also spleen/body weight rate of ethylacetate fraction was increased by 2.10% compared with the control (1.08%). And it is considered that there would be no toxic effect caused by each fraction of body weight and organ as there was on more changes in mouse' weight compared with the control.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.138-144
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• 2016

Phenoloxidase (PO) is an oxidizing enzyme and plays crucial roles in insect immunity and cuticle sclerotization. High oxidizing activity of chlorine dioxide gives effective control activities against microbes and insect pests. These allowed us to assess any inhibitory activity of chlorine dioxide against PO with respect to insect immunity. PO activities of the Indeanmeal moth, Plodia interpunctella, was detected in both hemocytes and plasma. Upon bacterial challenge, PO activity was significantly increased especially in plasma. However, the immune challenge coupled with chlorine dioxide treatment did not enhance PO activity. When different chlorine dioxide concentrations were incubated with activated PO by immune challenge, they did not inhibit the activated PO. These results indicate that chlorine dioxide suppresses PO activity by inhibiting PO activation.

• Korean Journal of Medicinal Crop Science
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• v.15 no.4
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• pp.296-303
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• 2007

Acer tegmentosum (Acereaceae) has been used a source of traditional medicines for the treatment of hepatic disorders in Korea. This research was conducted to determine biofunctional activities of A. tegmentosum stem extract and to identify its bioactive components. Methanolic extract from A. tegmentosum stem was partitioned by using organic solvents, including n-hexane, ethyl acetate, n-butanol, and water. Two compounds were isolated by using an ODS column chromatography from ethyl acetate soluble fraction shown to the strongest antioxidant activity ($RC_{50}=3.15\;{\mu}g/m{\ell}$) among the fractions. The isolated compounds were analyzed by $^1H$ and $^{13}C$ NMR, IR, UV/VIS, MS spectrum data and identified as catechin, ${\rho}-Hydroxyphenethyl$ alcohol $1-O-{\beta}-_D-(6'-O-galloyl)-glucopyranoside$. The compounds have shown strong antioxidant activity, with similar activity to BHA ($RC_{50}=2\;{\mu}g/m{\ell}$). Especially, ${\rho}-Hydroxyphenethyl$ alcohol 1-O-{\beta}-_D-(6'-O-galloyl)-glucopyranoside$ was shown strong anti-lipid peroxidative activity. However, the compounds were not shown antimicrobial activities. In antimicrobial activity assays, ethyl acetate soluble fraction was effective to bacterial inhibition, such as Escherichia coli and Klebsiella pneumonia, with minimum inhibitory concentrations in $125\;{\mu}g/m{\ell}$. Otherwise, antifungal activity against Candida albicans was shown in n-hexane soluble fraction exhibiting $63\;{\mu}g/m{\ell}$ of minimum inhibitory concentration. In anticomplementary activity assays, water soluble fraction was the most effective exhibiting 24% inhibitory activity.

• KSBB Journal
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• v.23 no.4
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• pp.329-334
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• 2008

The antioxidant activity and the qualitative analysis of Acanthopanax sessiliflorum Seeman were studied by partially purified extract using various methods: extraction by using ethanol solutions and temperatures, and absorption to Diaion HP20 column chromatography using 10%, 20%, 40%, 60% ethanol solutions. Major constituents, chlorogenic acid, caffeic acid, eleutheroside E, was determinated by HPLC method in Acanthopanax sessiliflorum S. 10% and 20% ethanol solutions contain chlorogenic acid (3.020$\pm$0.080%, 20.500$\pm$1.150%, respectively). 40% ethanol solution contains caffeic acid and eleutheroside E (12.270$\pm$0.360%, 1.670$\pm$0.140%, respectively). Diaion HP20 fractions (10%, 20%, 40%, 60% ethanol solutions) showed the scavenging activity of radicals and reactive oxygen species with the $IC_{50}$ values of $81.534{\pm}0.992{\mu}g/ml$, $1.748{\pm}0.098{\mu}g/ml$, $11.487{\pm}1.768{\mu}g/ml$, $21.960{\pm}0.547{\mu}g/ml$ against 1,1-diphenyl-2-picrylhydrazly radical and $1713.548{\pm}34.565{\mu}g/ml$, $131.419{\pm}2.235{\mu}g/ml$, $200.681{\pm}2.444{\mu}g/ml$, $757.897{\pm}6.868{\mu}g/ml$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. Especially, 20% and 40% ethanol fractions showed more antioxidant activity than dl-$\alpha$-tocopherol. These results suggest that Acanthopanax sessiliflorum S. extract and Diaion HP20 fractions may be useful as a potential source of nutraceutical and cosmetic products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.765-770
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• 2005

In this study, we investigated antimicrobial and cytotoxicity effects of Undaria pinnatifida Sporophyll, which using methanol, dichloromethane and ethanol were extracted and fractionated into four different types: methanol (UPMM), hexane (UPMH), butanol (UPMB) and aqueous (UPMA). The antimicrobial activity was increased in proportion to its concentration by the paper disc method. Among the solvent fractions, UPMM and UPMB showed relatively strong antimicrobial activities in the order. Among various partition layers, the methanol partition layer (UPMM) was showed the strongest cytotoxic effects on all cancer cell lines. We also observed quinone reductase (QR) induced effects in all fraction layers of UP on HepG2 cells. The QR induced effects of UPMH on HepG2 cells at $320\mu g/mL$ concentration indicated 2.36 with a control value of 1.0.

• Journal of Life Science
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• v.13 no.4
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• pp.529-534
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• 2003

This study was done to investigated the phytosterol compositions of safflower (Carthamus tinctorius L.) seed. The phytoestrogen activity was also determined using CAT-ELISA Kit in ethanol extract of safflower seed. The phytosterol of safflower seeds was identified using gas chromatography-mass spectrometry after saponification of the oils. The phytosterol content and composition of safflower seed oils were 4% and identified stigmast-5-en-3-ol (3$\beta$, 24S)-form, ${\gamma}$-sitosterol (clionasterol) with Wiley MS spectrum library. The synergistic effect of human estrogen receptor (hER) has been investigated using a minimal chimeric promoters composed of the TATA region of the adenovirus-2 major late promoter (A22MLP) and two consensus perfectly polindromic Xenopus vitellogenin A2 gene estrogen responsive elements (XVEREl19). Transient transfection experiments in tile human breast adenocarcinoma cell line MCF-7, which is known to express the estrogen receptor endogenously, revealed that phytoestrogen from Carthamus tinctorius L. acts as estrogen. We have observed the transcriptional activities stimulated methanol and ethanol extract of safflower seed in MCF-7, were 0.43 and 0.37 respectively, compared to that by $\beta$-estradiol as 1.0. Our data showed that safflower seeds have estrogenic activity methanol and ethanol extracts and ethanol lower than that of $\beta$-estradiol. This result provides the first evidence that the beneficial effect of safflower seeds may be mediated, at least in part, by the stimulating effect of phytoestrogen ell bone-protecting.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.84-87
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• 2008

In this research, we screened for glucosyltransferase (GTase) inhibitors that effectively prevent the dental caries from 420 kinds of boiled water extracts of herbs and wild plants and searched for GTase inhibitory activities. Among them, 13 kinds of hot water extracts had high GTase inhibitory activities and especially, we focused on Foeniculum vulgare which showed the highest inhibitory activity on GTase. The boiled water extract of F. vulgare was stable at high temperature and showed as a mixed type of competitive and uncompetitive inhibition kinetic behavior. It did not have antibacterial effect on Streptococcus mutans and had inhibitory activity on GTase. Specially, in the clinical trial, the group treated by boiled water extract of F. vulgare showed more decrease of plague index at 4.8 point than untreated group. These results suggested that boiled water extract of F. vulgare can effectively suppress the plague formation as it inhibits the GTase activity.