• Polymer(Korea)
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• v.33 no.3
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• pp.254-262
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• 2009

Nine kinds of hydroxypropyl celluloses (HPCs) with degree of substitution (DS) and molar substitution (MS) ranging from 2.10 to 2.71 and 2.3 to 6.7, respectively and seven kinds of fully butanoated HPCs (BPCs) based on the HPCs with $2.3\;{\le}\;MS\;{\le}\;6.7$ were synthesized, and the molecular characteristics of HPCs and the thermotropic liquid crystalline properties of the derivatives were investigated. MS was nearly equal to DS for small value of DS, but it became exceedly larger than DS for $DS{\gtrsim}1$, showing that in the later stages of reaction, propylene oxide preferentially adds to the side chains rather than the main chain. All the derivatives formed enantiotropic cholesteric phases with right-handed helical structures. The glass and clearing transition temperatures of both HPCs and BPCs were decreased with increasing MS. The optical pitches (${\lambda}_m'S$) of BPCs, as well as HPCs themselves, increased with increasing temperature. However, the ${\lambda}_m'S$ of both HPCs and BPCs at the same temperature increased with increasing MS. Moreover, the temperature dependence of ${\lambda}_m$ of HPCs was weaker than that of BPCs, suggesting that the helical twisting power of the cellulose chain highly depends on the length and chemical structure of the side chain introduced in cellulose chain.

• Korean Journal of Pharmacognosy
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• v.49 no.1
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• pp.76-83
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• 2018

A traditional herbal formula, Gyeji-tang has been used to treat the early colds, headache, chills, and fever in Asian countries. In this study, we were performed simultaneous determination of the 14 bioactive marker compounds, gallic acid, spinosin, paeoniflorin, albiflorin, liquiritin apioside, liquiritin, 6'''-feruloylspinosin, liquilitigenin, coumarin, cinnmamic acid, benzoylpaeoniflorin, cinnamaldehyde, glycyrrhizin, and 6-gingerol in Gyeji-tang using an ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS/MS). Analytical column was used a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$) and maintained at $45^{\circ}C$ with a flow rate of 0.3 mL/min. The mobile phase consists of 0.1% (v/v) formic acid in water and acetonitrile with gradient elution. The MS analysis was conducted using multiple reaction monitoring in the positive and negative modes by a Waters ACQUITY TQD LC-MS/MS system. The calibration curves of 14 bioactive marker compounds showed linearity with correlation coefficients ${\geq}0.9798$. The limits of detection and quantification values were in the range of 0.11-6.66 ng/mL and 0.34-19.99 ng/mL, respectively. As a result of the analysis using the established LC-MS/MS method, the amounts of tested 14 compounds in the lyophilized Gyeji-tang sample were detected up to $85.7{\mu}g/g$. These results may be useful for quality assessment of a traditional herbal formulas.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.926-931
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• 2007

Diarrhetic shellfish poisons (DSP) such as okadaic acid (OA), dinophysistoxin-1 (DTX1), pectenotoxin-1(PTX1), PTX2, PTX6 and yessotoxin (YTX) were determined simultaneously by LC-MS/MS and mouse bioassay in the shellfishes (oyster, mussel, Washington purple clam, ark shell, scallop and short necked clam) collected at Tongyeong, from March to September, 2006. Oyster and mussel were found to contain DSP (0.05${\sim}$0.1 MU/g) in March by mouse bioassay; however, no DSP components were detected on the LC-MS/MS. Also, a small amount of DTX1 (0.05 ${\mu}g/g$) in mussel (June) and OA (0.01${\sim}$0.02 ${\mu}g/g$) in 5 species of shellfishes(August) were determined by LC-MS/MS.

• Journal of Plant Biotechnology
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• v.1 no.2
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• pp.97-100
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• 1999

In order to establish in vitro propagation method of sundew, Drosera rotundifolia L., the effects of MS medium concentration, cytokinin type and concentration, pH, and auxin type and concentration on shoot proliferation and root formation were investigated using shoots at 3 month after seed germination. The highest shoot production was obtained with the half strength of MS ($\frac{1}{2}$ MS) medium than with any other strength of MS medium tested. Addition of kinetin or BA in $\frac{1}{2}$ MS medium was strongly suppressed shoot proliferation. The suppression of shoot proliferation was more effective in BA-supplemented $\frac{1}{2}$ MS medium than kinetin-supplemented. The optimum pH of the media for shoot proliferation was pH 5.7-6.7. Shoots were subcultured in $\frac{1}{2}$ MS medium supplemented with 0.5mg/L 2,4-D for rooting every 8 weeks. All subcultured shoots produced extensive root systems after 5 to 6 week culture. Plantlets after root development were planted in plastic pots filled with moss. The survival rate of plantlets was almost 100%. On subculturing every 8 weeks, hundreds of the plants were propagated from a single plant within a year.

• Korean Journal of Environmental Biology
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• v.23 no.4
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• pp.405-408
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• 2005

To induce the enhanced mutants of dinitroaniline herbicide pendimethalin degrading bacterium, Bacillus sp. MS202 was irradiated with gamma radiation at the dose of $LD_{99}$ (3.35 kGy). Three enhanced mutants (MS202m7, MS202m14, MS202m18) were isolated from the candidates by the generation - isolation method. Clear zone formation and the GC analysis confirmed that the degrading activity of each enhanced mutant (MS202m7, MS202m14, MS202m18), the formation of pendimethalin metabolite, increased by $11\%,\;45\%,\;and\;32\%$ than a wild type, respectively. It suggested that these mutants induced by gamma radiation could be useful for the application of pesticide degradation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1633-1640
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• 2018

Epoxy resin is a polar thermosetting polymer that is widely employed in different branches of industry and everyday life, due to their stable physical and chemical properties. Of all the polymer materials currently being used in the electrical insulation industry, epoxy resin is the most widely used kind, chosen as the base polymer material in the present study. Composites were prepared according to the mixing ratio (MS: MA, 1: 9, 3: 7, 5: 5, 7: 3, 9: 1)of mixture for Heterogeneous Minerals(Micro Silica:MS, Micro Alumina:MA) (MS+MA). We have investigated for AC electrical insulation breakdown characteristics and the dielectric properties (permittivity, dielectric loss, and conductivity) with frequency changes. The electrical AC insulation breakdown performance was improved with the increase of the mixing ratio of MS according to heterogeneous mineral material mixture(MS+MA). As Dielectric properties, the dielectric constant and dielectric loss increased with decreasing frequency and decreased with increasing MS content ratio of heterogeneous mineral mixture. Tensile strength and flexural strength according to the mixing ratio (MS + MA) of epoxy / heterogeneous mineral mixture were studied by mechanical properties. The performance of mechanical tensile and flexural strength was significantly improved as the fill contents ratio of MS increased.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1170-1178
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• 2011

In the present study, the approach of high accuracy mass measurements for phospholipid identifications was evaluated using a 7 T ESI-FTMS/linear ion trap MS/MS. Experiments were carried out for porcine brain, bovine liver, and soybean total lipid extracts in both positive and negative ion modes. In total, 59, 55, and 18 phospholipid species were characterized in the positive ion mode for porcine brain, bovine liver, and soybean lipid extracts, respectively. Assigned lipid classes were PC, PE, PEt, PS, and SM. In the negative ion mode, PG, PS, PA, PE, and PI classes were observed. In the negative ion mode, for porcine brain, bovine liver, and soybean lipid extracts, 28, 34, and 29 species were characterized, respectively. Comparison of our results with those obtained by other groups using derivatization-LC-APCI MS and nano-RP-LC-MS/MS showed that our approach can characterize PC species as effectively as those methods could. In conclusion, we demonstrated that high accuracy mass measurements of total lipid extracts using a high resolution FTMS, particularly, 7T FTMS, plus ion-trap MS/MS are very useful in profiling lipid compositions in biological samples.

• The Korean Journal of Zoology
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• v.29 no.3
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• pp.208-214
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• 1986

Comparative study of karyotypes in two allotypes $(Mdh-1^{MM} and Mdh-1^{MS})$ of the dark chub (Zacco temmincki) was examined. Both types had diploid number of 48 but the 7th chromosome was strikingly different between them. The chromosomes of $Mdh-1^{MM}$ type was consisted of 6 pairs of metacentrics, 6 pairs of submetacentrics, and 12 pairs of acrocentrics whereas the chromosomes of $Mdh-1^{MS}$ type had 7 pairs of metacentrics, 5 pairs of submetacentrics and 12 pairs of acrocentrics. No hybrid type between these two types was found in sympatric area at Tongchon River Namhae. Probable reproductive isolation between them was discussed.

• Analytical Science and Technology
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• v.19 no.3
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• pp.203-210
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• 2006

The determination of trace selenium in milk powder has been studied by octopole reaction cell(ORC)-ICP-MS. The interferences by polyatomic ions and other concomitant molecular species could be removed remarkably by using $H_2$ as reaction gas in ORC. Compared to the normal mode (no cell gas), the $H_2$ cell gas mode improved the accuracy and precision. The quantitative result was average 102.7% and it was slightly higher than certified standard value of milk powder and the RSD was 7.6%.

• YAKHAK HOEJI
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• v.60 no.1
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• pp.15-20
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• 2016

Globotriaosylsphingosine (lyso Gb3) is considered as one of the biomarkers for Fabry disease. A rapid and simple UPLC-MS/MS method was developed for the determination of reliable biomarker, lyso Gb3. Total analytical procedure takes only 15 min including sample preparation and MS/MS analysis. Limit of detection was 0.85 ng/ml (S/N=3). The calibration curve was linear over the range of 2.0~400.0 ng/ml ($R^2=0.9999$). Inter-day and intra-day assay accuracy were 93.4~100.6% (RSD, 0.6~6.0%) and 97.5~100.7% (RSD, 3.6~5.2%). Absolute recoveries of 97.6~98.6 showed excellence of a new analytical method. The method was applied to human and mice urines, proved the suitability for the quantification of lyso-Gb3 for screening, diagnosis and therapeutic monitoring of Fabry disease patients.