• Journal of Plant Biotechnology
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• v.33 no.2
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• pp.147-152
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• 2006

This work was carried out to establish adventitious root culture system in three Panax species (wild-grown P. ginseng, P. quinquefolium, and P. japonicum) to analyze their ginsenoside productivity. Adventitious roots were induced directly from segments of seedlings after cultured on MS(Murashige andSkoog 1962) solid medium containing 3.0 mg/l IBA. Omission of $NH_4NO_3$ from the medium greatly enhanced both the frequency of adventitious root formation and number of roots per explants in all the three Panax species. However, elongation of post-induced adventitious roots was enhanced on medium with $NH_4NO_3$. Two-step culture protocol: $NH_4NO_3$-free medium for first two weeks of culture, followed by $NH_4NO_3$ containing medium for further 4 weeks, greatly enhanced the fresh weight increase of adventitious roots in all the three ginseng species. The fresh weight of adventitious roots was high in P. quinquefolium and low in P. ginseng, followed by P. japonioum regardless of the composition of medium. Pattern and content of ginsenosides in adventitious roots differed among the three Panax species. Total ginsenoside content of adventitious roots in P. quinquefolium, P. ginseng, and p. japonicum was 8.03, 15.7 and 1.2 mg/g dry weight, respectively. Among the three speices, adventitious roots in P. quinquefolium produced hig-hamount of ginsenosides. The pattern of ginsenoside fractions between P. ginseng and P. quinquefolium was similar but the amount of ginsenoside differed between the two, While, in P japonicum, total ginsenoside content was very low and some ginsenosides such as ginsenoside Rb2 and Rf were not detected. Conclusively, we demonstrate that same culture condition was required for induction and elongation of adventitious roots of three ginseng species but growth of adventitious roots and their ginsenoside production were different among them.

• Journal of the Korean Chemical Society
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• v.40 no.6
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• pp.394-400
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• 1996

The conformational transitions of oligopeptide -(HPPHPPP)$_n$- (H: hydrophobic amino acid, P: polar amino acid) which becomes cross linked-dimer are detected at various temperatures, pHs, ionic strengths, and the concentrations of denaturant. In this study, the transitions of oligopeptide due to denaturant, and those due to temperature are theoretically studied. Oligopeptide 20R as chain-dimer and guanidum-HCl as denaturant are used(20R, which contains 10 interchain and /or 10 intrachain electrostatic repulsions). Alpha helix-coil transitions by denaturant are very steep. This shows that the denaturations have transition states of, presumably all helical forms and random coils. The transitions by temperature are smoother than those by the concentration of denaturant. At low temperature the oligopetides which contain long helices exist more than those which contain short helices. As temperature rises, the mole fractions of the partially denatured oligopeptides increase. So the partially denatured oligopeptides are widely distributed at the transition temperature.

• Journal of the Korean Ceramic Society
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• v.48 no.5
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• pp.418-425
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• 2011

In this study, a high energy ball milling process was introduced in order to improve the densification of direct nitrided AlN powder. The sintering behavior and thermal conductivity of the AlN milled powder was investigated. The mixture of AlN powder and 5 wt% $Y_2O_3$ as a sintering additive was pulverized and dispersed by a bead mill with very small $ZrO_2$ bead media. The milled powders were sintered at $1700^{\circ}C-1800^{\circ}C$ for 4 h under $N_2$ atmosphere. The results showed that the sintered density was enhanced with increasing milling time due to the particle refinement as well as the increase in oxygen contents. Appropriate milling time was effective for the improvement of thermal conductivity, but the extensive millied powder formed more fractions of secondary phase during sintering, resulted in the decrease in thermal conductivity. The AlN powder milled for 10min after sintering at $1800^{\circ}C$ revealed the highest thermal conductivity, of 164W/$m{\cdot}K$ in tne densified AlN sintered at $1800^{\circ}C$.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.395-404
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• 2011

Asian dust evens took place in Seoul on 27~28 March and 31 March~1 April 2007, during which the mass and chemical compositions of $PM_{10}$ were measured at urban area in Seoul, Korea. In conjunction with $PM_{10}$ compositions, the behaviors of gas precursors such as CO, $O_3$, $SO_2$, and $NO_2$ and meteorological parameters and air mass trajectories were thoroughly examined. The earlier case was a weak dust incidence which was characterized by elevated concentrations of CO, $SO_2$ and $NO_2$ as well as secondary aerosols. In contrast, the later showed the trait of the dust aerosols associated with high $PM_{10}$ mass and $Ca^{2+}$ concentrations. In general, the fractions of ionic species against mass decreased with increase in dust loading. The ratios of ${SO_4}^{2-}$ to ${NO_3}^-$ and $SO_2$ to $NO_2$ were similar in temporal variations, suggesting the concentrations of secondary aerosols were sensitive to the level of precursor gases. In this study, $Na^+$ and $Cl^-$ were also highly elevated during the heavy dust episode, which is thought to have originated from alkaline soils spreading through the northeast regions of China.

• Food Engineering Progress
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• v.15 no.4
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• pp.413-419
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• 2011

For producing a high added-value natural seasoning ingredient, a yeast extract (Yx) was supplemented with a rice protein residue fermented with Bacillus licheniformis (Rfl) or with Bacillus subtilis (Rfs). A rice protein residue was obtained after enzymatic hydrolysis of rice protein which was used for preparing a yeast culture medium. Overall acceptabilities of the supplemented yeast extracts (YxRfl or YxRfs) were higher compared to pure yeast extract. Savory taste like umami was found to increase noticeably by adding a fermented rice protein residue to yeast extract, which was confirmed in taste sensor analysis and in sensory test. Beyond the presence of savory tasting amino acids such as Glu and Asp in a fermented rice protein residue, it is assumed that other soluble peptide fractions remained play an important role in enhancing taste of the supplemented yeast extracts. Thus, the yeast extract added with a fermented rice protein residue could be applied to manufacture a natural seasoning ingredient.

• Journal of Mushroom
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• v.19 no.4
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• pp.341-346
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• 2021

Simple sequence repeats (SSRs) were isolated from major Pleurotus pulmonarius cultivars in Korea, namely 'HS47' (monokaryon, gamete of 'Santari'), 'GB19' (monokaryon, gamete of 'Santari'), 'Hosan,' 'Yeoleumneutali1,' 'Sambok,' 'Gangsan,' 'Yaksan,' 'Jasan,' 'Hyangsan,' and 'Yeoleumneutali2,' and characterized via HiSeq genome sequencing and bioinformatic analysis. The genome sizes of the monokaryons 'HS47' and 'GB19' were estimated to be 37.3 and 37.2 Mb, respectively, and those of the other dikaryotic cultivars ranged from 47.1 to 61.1 Mb. A total of 711 (smallest) and 1,106 (1.5 times the smallest) SSRs were found in the 'HS47' and 'Gangsan' genomes, respectively. Hexanucleotide and octanucleotide motifs accounted for the top two fractions of all SSRs. CGA/TCG, A/T, and CTC/GAG were the most frequently detected nucleotides in the SSRs. Most of the SSRs were 21~30 nucleotides long (hypervariable for application), accounting for 70% of all lengths of SSRs.

• Korean Journal of Pharmacognosy
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• v.53 no.1
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• pp.8-15
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• 2022

Robinia pseudoacacia L. (Leguminosae) is widely distributed in Asia, North America and Europe. The root bark has been traditionally used for hemostasis, arthritis and hypertension. Therefore, this study was conducted to identify the biological activity and the bioactive constituents of the root bark. We found that the methanol extract obtained from the root bark of R. pseudoacacia reduced the level of ROS and NO production in LPS-induced inflammation of RAW 264.7 cell line. Among the fractions, methylene chloride fraction showed the highest inhibitory activity against the inflammation. Seven constituents (1-7) were isolated from this fraction, and the chemical structures were determined to be medicarpin (1), (-)-vestitol (2), indole 3-carboxaldehyde (3), 3-acetylindole (4), liquiritigenin (5), 4(1H)-quinolone (6) and 8-methoxyononin (7). Among the isolates, medicarpin (1), (-)-vestitol (2), 3-acetylindole (4) and liquiritigenin (5) inhibited ROS and NO production in a dose-dependent manner. This is the first study to show the anti-inflammatory activity of the root bark of R. pseudoacacia, and it is suggested that the four constituents (1, 2, 4, and 5) could play a role in the biological activity.

• Anatomy and Cell Biology
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• v.56 no.2
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• pp.236-251
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• 2023

Alcohol consumption alongside combination antiretroviral therapy (cART) has attracted research interest, especially because of increasing male infertility. This study investigated the combined effects of alcohol and cART on testicular morphology, biomarkers of oxidative stress, inflammation, and apoptosis. Rats, weighing 330-370 g, were divided into four groups of six animals each; control, alcohol treated (A), cART, and alcohol plus cART treated (A+cART). Following 90 days treatment period, animals were euthanized, testis extracted, and routinely processed for histology and immunohistochemical analysis. Significantly decreased epithelial area fraction, increased luminal and connective tissue area fractions, and reduction of epithelial height and spermatocyte number, were recorded in the treated groups compared to control. Extensive seminiferous epithelial lesions including widened intercellular space, karyolysis, and sloughing of germinal epithelium were recorded in all the treated groups. Furthermore, upregulation of inducible nitric oxide synthase and 8-hydroxydeoxyguanosine, interleukin-6, and caspase 3 recorded in treated animals, was more significant in A+cART group. Also, the levels of interleukin-1β and tumor necrosis factor-α were more elevated in A and cART treated groups than in A+cART, while MDA was significantly elevated in cART and A+cART treated groups compared to control group. Altogether, the results indicate testicular toxicity of the treatments. It is concluded that consuming alcohol or cART induces oxidative stress, inflammation, and apoptosis in testis of rats, which lead to testicular structural and functional derangements, which are exacerbated when alcohol and cART are consumed concurrently. The result will invaluably assist clinicians in management of reproductive dysfunctions in male HIV/AIDS-alcoholic patients on cART.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2195-2207
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• 2024

To enhance skeletal dosimetry in conjunction with the adult mesh-type reference Korean phantoms (MRKPs), Korean/Asian photon fluence-to-skeletal dose response functions (DRFs) were established utilizing an updated version of micro-CT-based detailed bone models from Tsinghua University. These bone models were incorporated into the MRKPs using the parallel geometry feature of Geant4. We calculated bone-site-specific electron absorbed fractions and used them to generate DRFs, following a similar methodology employed for ICRP-116 DRFs that have been used with the ICRP reference phantoms for skeletal dosimetry. To assess dosimetric implications of the Korean/Asian DRFs, we calculated RBM and BE doses for the MRKPs exposed to photon beams in the antero-posterior direction using the Korean/Asian and ICRP-116 DRFs. For energies ≥200 keV, the Korean/Asian DRFs-based skeletal doses exhibited excellent agreement with the ICRP-116 DRFs-based skeletal doses, attributed to the existence of charged particle equilibrium across the bone site. Conversely, significant differences of up to ~2.3 times were observed at lower energies, due to differences in the skeletal tissue distributions of bone models used to derive the Korean/Asian and ICRP-116 DRFs. The DRFs established in this study are expected to yield more accurate skeletal doses for Korean and Asian populations compared to the ICRP-116 DRFs.

• 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.