• Geophysics and Geophysical Exploration
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• v.10 no.4
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• pp.241-251
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• 2007

The observed spectra from Odaesan earthquake were fitted to a point-source spectral model to evaluate the source spectrum and spatial features of the modelling error. The source spectrum was calculated by removing from the observed spectra the path and site dependent responses (Yun, 2007) that were previously revealed through an inversion process applied to a large accumulated spectral dataset. The stress drop parameter of one-corner Brune's ${\omega}^2$ source model fitted to the estimated source spectrum was well predicted by the scaling relation between magnitude and stress drop developed by Yun et al. (2006). In particular, the estimated spectrum was quite comparable to the two-corner source model that was empirically developed for recent moderate earthquakes occurring around the Korean Peninsula, which indicates that Odaesan earthquake is one of typical moderate earthquakes representative of Korean Peninsula. Other features of the observed spectra from Odaesan earthquake were also evaluated based on the commonly treated random error between the observed data and the estimated point-source spectral model. Radiation pattern of the error according to azimuth angle was found to be similar to the theoretical estimate. It was also observed that the spatial distribution of the errors was correlated with the geological map and the $Q_0$ map which are indicatives of seismic boundaries.

• Journal of Ginseng Research
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• v.42 no.3
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• pp.270-276
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• 2018

Background: Notoginsenoside Ft1 is a promising potential candidate for cardiovascular and cancer disease therapy owing to its positive pharmacological activities. However, the yield of Ft1 is ultralow utilizing reported methods. Herein, an acid hydrolyzing strategy was implemented in the acquirement of rare notoginsenoside Ft1. Methods: Chemical profiles were identified by ultraperformance liquid chromatography coupled with quadruple-time-of-flight and electrospray ionization mass spectrometry (UPLC-Q/TOF-ESI-MS). The acid hydrolyzing dynamic changes of chemical compositions and the possible transformation pathways of saponins were monitored by ultrahigh-performance LC coupled with tandem MS (UHPLC-MS/ MS). Results and conclusion: Notoginsenoside Ft1 was epimerized from notoginsenoside ST4, which was generated through cleaving the carbohydrate side chains at C-20 of notoginsenosides Fa and Fc, and vinaginsenoside R7, and further converted to other compounds via hydroxylation at C-25 or hydrolysis of the carbohydrate side chains at C-3 under the acid conditions. High temperature contributed to the hydroxylation reaction at C-25 and 25% acetic acid concentration was conducive to the preparation of notoginsenoside Ft1. C-20 epimers of notoginsenoside Ft1 and ST4 were successfully separated utilizing solvent method of acetic acid solution. The theoretical preparation yield rate of notoginsenoside Ft1 was about 1.8%, which would be beneficial to further study on its bioactivities and clinical application.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.337-344
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• 2015

Medicinal plants containing wellness-fusion-complex compound are increasingly being pursued as suitable alternative sources of various biological properties. In this study, inhibitory effect of Quintinia acutifolia, which is a New Zealand plant, on P388 murine lymphocytic leukemia cells using MTT [3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-tetrazolium bromide] assay. Based on $^1H-NMR$, $^{13}C-NMR$ spectral data and other spectral analysis, 2,3,2'',3''-tetrahydroochanaflavone (1) and 2'',3''-dihydroochana-flavone (3) inhibited the leukemia cells were purified from the plants. 2,3,2'',3''-tetrahydroochanaflavone (1) and 2'',3''-dihydroochana-flavone (3) are biflavonoids possessing two basic flavonoids and actively inhibited growth of P388 murine lymphocytic leukemia cells with a 50% inhibitory concentration ($IC_{50}$) of $8.2{\mu}g/mL$ and $3.1{\mu}g/mL$, respectively. Specially, 2'',3''-dihydroochana-flavone (3) possessed unconjugated flavonone system, which isn't consist of a pair with B ring of 2,3,2'',3''-tetrahydroochanaflavone (1). Therefore, the two compounds could be considered as a candidate for development of anticancer drugs and need to much studies in the future.

• Korean Journal of Environment and Ecology
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• v.27 no.1
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• pp.64-70
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• 2013

To examine the proportion of secondary seed dispersion by wildlife and to identify the related wildlife, We measured seed removal rates and related wildlife at the natural mixed broadleaved forest in mountain Jungwang, Pyeungchang-gun in middle part of Korean peninsula, seed-tray contained four kind of tree seeds were setted from mid-september to late-October for three years. Mean seed removal rates(MSRR) of acorn(Q. mongolica)is shown the highest values 87.2%, next MSRR of samara(A. pseudosieboldianum) does 33.1%, MSRR of samara(A. pictum subsp. mono) does 29.2%. and then SRR of samara(A. mandshuricum) does only 13.6%. Acorns are removed more faster than samaras. Among the related wildlife, Siberian chipmunks most freqently visit seed tray, and ordered Korean squirrel, Wild boar, and Yellow-throated marten. Most secondary dispersed acorns might be consumed by Wild boar, and small portions does comsumed or scatter-hoarded by rodents. Most secondary dispersed samaras might be consumed by rodents, and small portions does scatter-hoarded by rodents. A few sound seeds are remained on the forest floor in late October owing to the seed consunption and seed hoarding by wildlife. We observe seedling establishment of four broadleaved tree species. From these results, We proved Wild boar is seed comsummer, and rodents are seed consummer and seed disperser. Further studies on secondary seed dispersion, seed consumption and hoarding and related wildlife should be needed.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.810-820
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• 2016

This study is focused on the investigation of the genes which are induced by various stresses of the halophyte Salicornia herbacea. One of the factors influencing in the germination of Salicornia herbacea is salt stress. The highest germination rate was found in the condition without NaCl, and the upper limit of the NaCl concentration for the germination of Salicornia herbacea was 7%. The optimal temperature of $20^{\circ}C$showed a germination rate of 98%. Among genes induced by stress the 2CysPrx gene was cloned and analyzed for this study. The 2CysPrx gene has two cysteine conserved residues and is composed of 275 amino acids with molecular weight of 30.1kDa. The 2CysPrx gene appeared to be one copy in the genome and consists of 6 introns and 7 exons. Quantitative real-time PCR revealed that the highest transcription rate induced by NaCl and $H_2O_2$ appeared to be at the concentration of 3.5% NaCl and 40mM $H_2O_2$, respectively. The amount of transcript induced by high temperature($40^{\circ}C$) and $75{\mu}M$ of ABA was respectively highest. The gene at low temperature ($4^{\circ}C$) appeared not to be expressed. We are conducting to clone other peroxyredoxin genes induced by various environmental stresses.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.12 no.2
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• pp.77-81
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• 2016

The Dandy-Walker syndrome is a relatively rare congenital malformation occurring about one in 25,000-35,000 pregnancies. It is characterized by hydrocephalus, cystic dilatation of the fourth ventricle, complete or partial absence of the cerebellar vermis, and other various extra-CNS malformations. We report a dental caries treatment of a 4-year old girl with Dandy-Walker syndrome and partial trisomy 9q. The patient visited Seoul National University Dental Hospital due to multiple caries. The cause of multiple caries is mainly presumed as patient's eating habit caused by her general condition. She was still using milk bottle because she was having difficulties swallowing solid food due to breathing problem while eating. The treatment was performed under general anesthesia considering patient's condition; delayed development, very poor cooperation and respiratory problem. The dental procedure was successfully conducted and there were no postoperative complications. In consideration of her eating habit and oral hygiene problem, regular check appointment was recommended.

• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.2
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• pp.71-84
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• 2014

The full-length heat shock protein 88 (HSP88) complementary DNA (cDNA) of Paecilomyces tenuipes Jocheon-1 was obtained by screening the Paecilomyces tenuipes (P. tenuipes) Jocheon-1 Uni-Zap cDNA library and performing 5' RACE polymerase chain reaction (PCR). The P. tenuipes Jocheon-1 HSP88 cDNA contained an open reading frame (ORF) of 2,139-basepair encoding 713 amino acid residues. The deduced amino acid sequence of the P. tenuipe s Jocheon-1 HSP88 cDNA showed 77% identity to Nectria haematococca HSP88 and 45-76% identity to other fungal homologous HSP88s. Phylogenetic analysis and BLAST program analysis confirmed that the deduced amino acid sequences of the P. tenuipes Jocheon-1 HSP88 gene belonged to the ascomycetes group within the fungal clade. The P. tenuipes Jocheon-1 HSP88 also contained the conserved ATPase domain at the N-terminal region. The cDNA encoding P. tenuipes Jocheon-1 HSP88 was expressed as an 88 kilodalton (kDa) polypeptide in baculovirus-infected insect Sf9 cells. Under higher temperature conditions for the growth of the entomopathogenic fungus, mRNA expression of P. tenuipes Jocheon-1 HSP88 was quantified by real time PCR (qPCR). The results showed that heat shock stress induced a higher level of mRNA expression compared to normal growth conditions.

• Korean Journal of Materials Research
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• v.19 no.4
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• pp.198-202
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• 2009

For use in ultrasonic actuators, we investigated the structural and piezoelectric properties of $(1\;-\;x)Pb(Zr_{0.515}Ti_{0.485})O_3$ - $xPb(Sb_{1/2}Nb_{1/2})O_3$ + 0.5 wt% $MnO_2$ [(1 - x)PZT - xPSN + $MnO_2$] ceramics with a variation of x (x = 0.02, 0.04, 0.06, 0.08). All the ceramics, which were sintered at $1250^{\circ}C$ for 2 h, showed a typical perovskite structure, implying that they were well synthesized. A homogeneous micro structure was also developed for the specimens, and their average grain size was slightly decreased to $1.3{\mu}m$ by increasing x to 0.8. Moreover, a second phase with a pyrochlore structure appeared when x was above 0.06, which resulted in the deterioration of their piezoelectric properties. However, the 0.96PZT-0.04PSN+$MnO_2$ ceramics, which corresponds with a morphotropic phase boundary (MPB) composition in the (1 - x)PZT - xPSN + $MnO_2$ system, exhibited good piezoelectric properties: a piezoelectric constant ($d_{33}$) of 325 pC/N, an electromechanical coupling factor ($k_p$) of 70.8%, and a mechanical quality factor ($Q_m$) of 1779. The specimens with a relatively high curie temperature ($T_c$) of $305^{\circ}C$ also showed a significantly high dielectric constant (${\varepsilon}_r$) value of 1109. Therefore, the 0.96PZT - 0.04PSN + $MnO_2$ ceramics are suitable for use in ultrasonic vibrators.

• Mycobiology
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• v.46 no.1
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• pp.64-71
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• 2018

The aim of this study was to investigate the pattern of distribution of mating type (MAT) genes of Tuber indicum in ectomycorhizosphere soils from natural T. indicum-producing areas and cultivated truffle orchards and ascocarp samples from different regions. Quantitative real-time PCR and multiplex PCR were used to weight the copy numbers of MAT1-1-1 and MAT1-2-1 in natural truffle soils and cultivated orchard soils. The effect of limestone on the pattern of truffle MAT genes and the correlation between soil properties and the proportion of MAT genes were also assessed. These results indicated that an uneven and nonrandom distribution of MAT genes was common in truffle-producing areas, cultivated truffle orchards, and ascocarps gleba. The competition between the two mating type genes and the expansion of unbalanced distribution was found to be closely related to truffle fructification. Limestone treatments failed to alter the proportion of the two mating type genes in the soil. The content of available phosphorus in soil was significantly correlated with the value of MAT1-1-1/MAT1-2-1 in cultivated and natural ectomycorhizosphere soils. The application of real-time quantitative PCR can provide reference for monitoring the dynamic changes of mating type genes in soil. This study investigates the distributional pattern of T. indicum MAT genes in the ectomycorhizosphere soil and ascocarp gleba from different regions, which may provide a foundation for the cultivation of T. indicum.

• Journal of Korea Water Resources Association
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• v.38 no.1
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• pp.1-9
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• 2005

The study shows the possible use of the index flood frequency curves for an estimation of flood quantiles at ungauged locations. Flood frequency analysis were made for the annual maximum flood data series at 9 available stations in the Han river basin. From the flood frquency curve at each station the mean annual flood of 2.33-year return period was determined and the ratios of the flood magnitude of various return period to the mean annual flood at each station were averaged throughout the Han river basin, resulting mean flood ratios of different return periods. A correlation analysis was made between the mean annual flood and physiographic parameters of the watersheds i.e, the watershed area and mean river channel slope, resulting an empirical multiple linear regression equation over the whole Han river basin. For unguaged watershed the flood of a specified return period could be estimated by multiplying the mead flood ratio corresponding the return period with the mean annual flood computed by the empirical formula developed in terms of the watershed area and river channel slope. To verify the applicability of the methodology developed in the present study the floods of various return periods determined for the watershed in the river channel improvement plan formulation by the Ministry of Construction and Transportation(MOCT) were compared with those estimated by the present method. The result proved a resonable agreement up to the watershed area of approximately 2,000k $m^2$. It is suggested that the practice of design flood estimation based on the rainfall-runoff analysis might have to be reevaluated because it involves too much uncertainties in the hydrologic data and rainfall-runoff model calibration.