• Korean Journal of Food Science and Technology
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• v.17 no.4
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• pp.265-270
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• 1985

The saponin yield and its compositional changes of red ginseng extract (RG-EXT) was investigated during extraction at various temperature for 5 times of 8 hours. The higher temperature resulted an increase in solids yield while the total saponin recovered was decreased, particularly at $100^{\circ}C$. A relatively lower thermal stability was found for protopanaxadiol saponin, one of the saponin fractions, than protopanaxatriol saponin. The compositional ratio of saponin at ginsenoside level was little affected by extraction time. The yields data showed that more than 94% of total saponin was recovered by 3$\sim$4 times of 8 hours extraction. Extraction at $80^{\circ}C$ for 4 times of 8 hours were suggested for preparation of RG-EXT from the result of this work.

• Korean Journal of Food Science and Technology
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• v.13 no.1
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• pp.20-24
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• 1981

Residues of neoasozine in rice grain were determined by neutron activation and colorimetric techniques. Twice application of the chemical before flowering did not lead to any increased residue level while 4-times application resulted in significant increase in the residue level up to 0.54-0.75 mg $As_2O_3/kg$. The partition ratio of arsenic residues into polished rice grain and bran was 73 : 27 in 100% polishing while most of the residues in the bran was transferred to oil cake fraction during solvent extraction, reaching up to 2.9 mg $As_2O_3/kg$. The neutron activation technique was advantageous because of its high sensitivity and the smaller sample amounts required for analysis.

• Polymer(Korea)
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• v.35 no.5
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• pp.402-408
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• 2011

To improve $Na^+$-saponite(SPT) film flexibility, we prepared SPT hybrid clay films with various poly(vinyl alcohol) (PVA) concentrations(0~10 wt%) using the solution intercalation method. In this study, we investigated the thermo-optical properties, morphology, and gas permeability of the SPT hybrid films. We also examined the relationship between the film properties and PVA content using wide angle X-ray diffraction measurements(XRD), field emission scanning electron microscopy(FESEM), differential scanning calorimetry(DSC), thermogravimetric analysis(TGA), thermomechanical analysis(TMA), ultraviolet-visible(UV-vis) spectroscopy, and oxygen transmission rate($O_2$TR) testing. The properties of the clay hybrid films were strongly affected by PVA filler content. The presence of a small amount of PVA was sufficient to improve the flexibility of SPT hybrid films.

• Polymer(Korea)
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• v.37 no.2
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• pp.225-231
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• 2013

Poly(vinyl alcohol) (PVA) hybrid films containing 5 wt% pristine clay mineral were synthesized in the water solution. The various PVA hybrid films were synthesized from structurally different pristine clays: saponite (SPT), montmorillonite (MMT), hectorite (SWN), hydrophilic bentonite (PGV), and mica (Mica). The thermo-optical properties and morphologies of the PVA hybrid films were evaluated with various pristine clays. The nanostructure of the hybrid films was observed using transmission electron microscopy, which showed that the clay layers were well dispersed into the matrix polymer, although some clusters or agglomerated particles were also detected. The addition of pristine clay was more effective with regard to improving the thermal properties and gas barrier characteristics, whereas the optical transparency of the PVA hybrid films deteriorated with pristine clay.

• Polymer(Korea)
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• v.30 no.6
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• pp.545-549
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• 2006

Blends of poly(acrylic acid- co-maleic acid) (PAM) with poly (vinyl alcohol) (PVA) were pre -pared in distilled water PVA/PAM/saponite (PVA/PAM/SPT) nanocomposite films were prepared with various clay contents by using the solution intercalation method. The variations of the dispersion, morphology, and thermo-mechanical properties of the nanocomposites with clay content in the range 0 to 9 wt% were examined. Up to 3 wt% clay loading, the clay particles were homogeneously dispersed in the PVA/PAM blends. However, some agglomerated structures form in the polymer matrix above a clay content of 7 wt%. The thermal stability of the hybrids was increased linearly with increasing the clay loading up to 9 wt%. The maximum strength and modulus were obtained at a clay content of 7 wt%. Thus, the addition of small amounts of clay to the PVA/PAM blends produced PVA/PAM nano-composites with improved the thermo-mechanical properties.

• Journal of the Korean Chemical Society
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• v.36 no.3
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• pp.419-427
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• 1992

The performance of homemade thermal field-flow fractionation (ThFFF) and the optimization for separation are investigated in terms of retention parameters and selectivity using polystyrene standards. The ribbonlike channel was constructed by sandwiching two Mylar spacers between two highly polished copper bars which serve as channel walls. The hot bar was heated by two electrical cartridge heaters and the cold bar had holes through the entire length, allowing tap water as coolant to enter. It has been observed that the retention of polystyrenes increases as the temperature gradient increases. And the retention decreases as the cold wall temperature increases from 20 to $45^{\circ}C$. In comparison with size exclusion chromatography, ThFFF is more selective but has relatively low efficiency. It has been found that the plate height is proportional to the flow velocity and good estimates of polydispersities can be made directly from the ThFFF data.

• Journal of Ginseng Research
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• v.19 no.1
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• pp.62-72
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• 1995

During the controlled atmosphere storage (CA), fresh ginseng showed good appearance in quality, and other deterioration of freshness was not observed until 12 weeks. On the other hand, MA storage had kept freshness only in treatment of 1 until 8 weeks. There was no significant difference between treated and non-treated sample with preservatives, and not treated sample was not infected with various different fungi. Moisture contents and hardness of ginseng in all treatments were not changed much until 12 weeks, and surface shrinkage did not occur either. But shear stress increased somewhat in all treatments after 12 weeks. The granule of microstructure in tissue diminished slightly. The apparent Quality of red ginseng was good until 4 weeks of treatment. But as time passed, white skin and wrinkled skin were generated and darkened in its color. B-1 in CA and E-1 in MA were found to be the most favorable one. The content of crude saponin did not change significantly during storage of CA or MA by preservation conditions and period. Though a small increase in saponin content from 4.92% to 5.43% was recognized in B-1, which was treated with preservative and 6.0% In B-2, control, this could rather explain increment of soluble component by butanol. Thus, there was no change in total contents of ginsenoside pattern and composition of each content. The Rbl content in B-1 and B-2 were 0.98%, and 0.97%, respectively, whereas that of control was 0.96%. E-1 of MA, treated with preservative was 5.32% after 12 weeks, but was 5.73% in control, indicating that ginsenosides pattern was quite similar to that of CA storage.

• Restorative Dentistry and Endodontics
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• v.29 no.2
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• pp.185-190
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• 2004

자가산부식 접착제 (self-etching primer)는 법랑질과 상아질을 동시에 산부식과 프라이머 처리를 함으로 임상 시술 시간을 단축시킬 뿐만 아니라, 임상과정 중 발생할 수 있는 술자의 실수 및 타액등에 의한 오염의 가능성을 줄일 수 있는 장점을 가지고 있다. 그러나 약산을 이용한 산부식법이 법랑질에 대해 탈회효과 및 접착강도에 있어 논란이 되고 있다. 이에 본 연구에서는 인산을 이용한 추가적인 산부식 및 자가산부식 접착제의 적용시간을 달리할 경우 법랑질에 대한 접착강도의 변화를 알아보고자 하였다. 135개의 발거한 우치의 법랑질 면을 ＃600사포로 연마한 후 9개의 군으로 분류하였다. 각 군은 부가적인 32% 인산을 처리하지 않은 군 (1~3군), 15초간 처리한 군 (4~6군), 60초간 처리한 군 (7~9군)으로 나누고, 이를 다시 Clearfil SE Bond의 프라이머로 5초 (1, 4, 7군), 20초 (2, 5, 8군), 60초 (3, 6, 9군)간 처리한 군으로 분류하였다. 접착제 처리한 면에 Clearfil AP-X 복합레진을 접착하고 24시간 경과 후 전단응력 강도를 측정하였다. 결과는 One-way ANOVA 처리후 Duncan's multiple range test로 사후검증하였다. 동일한 자가산부식 프라이머 처리 시간을 가진 군에서 산 부식을 한 경우가 그렇지 않은 군에 비해 높은 접착강도를 나타내었으며 인산부식 시간의 차이에 의한 영향은 없었다.(1 < 4, 7군/ 2 < 5, 8군/ 3 < 6, 9군). 자가산부식제의 프라이머 적용 시간에 의한 효과는 1군(5초 적용)을 제외한 나머지 군의 경우 동일한 인산 처리군에서는 차이가 없는 것으로 나타났다.(1군 < 2, 3군/ 4＝5＝6군/ 7＝8＝9군). Clearfil SE Bond 접착제의 법랑질에 대한 접착강도는 부가적인 산부식을 통하여 증가시킬 수 있으며 프라이머의 적용 시간에 의한 효과는 제조자의 지시에 의한 시간 이상 적용할 경우 차이가 없는 것으로 나타났다.

• Korean Journal of Pharmacognosy
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• v.34 no.3 s.134
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• pp.237-241
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• 2003

This study was carried out to test the growth inhibitory effects of sesamolin obtained from sesame seeds. Sesamolin inhibited the growth of human leukemia HL-60 cells in cultures and the synthesis of macromolecules in dose- and time-dependent manners. Sesamolin in the $60{\sims}100\;{\mu}g/ml$ range was cytostatic. At concentrations greater than $200\;{\mu}g/ml$ sesamolin was cytocidal to HL-60 cells and at $60\;{\mu}g/ml$ inhibited the synthesis of DNA, RNA and protein in HL-60 cells by 35.1, 6.1, and 5.3%, whereas at $200\;{\mu}g/ml$ these inhibitions were 86.8%, 81.5% and 96.7%, respectively. The inhibitory effect of sesamolin on DNA synthesis was irreversible.

• Journal of Ginseng Research
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• v.18 no.1
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• pp.1-9
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• 1994

Sprague-Dawley rats were given freely with 15% ethanol (control) and 15% ethanol containing (1) 0.1% ginseng saponin, (2) 0.02% ginsenoside $Rb_1$, and (3) $Rg_1$ (tests) instead of water for 7 days and aldehyde dehydrogenase (ALDH) and monoamine oxidase (MAO) activity in different regions of brain were examined. In control group, total ALDH activity with indoleacetaldehyde and acetaldehyde as substrate in all different regions was lower than that of normal group except in the hippocampus. The inhibitory effect on the activity was prominent in the corpus striatum and was not in the hippocampus. However, low-$K_m$ ALDH activity in all different regions was much lower than that of normal group. A considerable decrease in mitochondria ALDH activity in cerebellum and striatum was also observed in control group. In test groups total, low-$K_m$, and mitochondria AkDH activities in all different regions were higher than those in control group. Although ALDH activity in the striatum of test group was higher than control group, it was relatively depressed as compared with normal. There was not found a remarkable difference in extent of stimulating effect on the AkDH activity according to the ginseng saponin components. When biogenic aldehydes were used as substrate, ALDH activity with 3,4-dihydroxy-phenylacetaldehyde (DOPAL) in all brain regions of control group was lower than that using 5-hydroxy-indoleacetaldehyde (HIAL) and 3,4-dihydroxyphenylglycolaldehyde (NORAL) as substrate. In control group, ALDH activity with biogenic aldehydes above mentioned was markedly inhibited in the striatum contrary to other regions. The higher ALDH activity with biogenic aldehydes in test group than in control was found in the striatum, cerebrum, and cerebellum. MAO activity in the cerebellum was inhibited in control group and slightly increased in test group. The results of present study suggest that the corpus striatum is significantly affected by ethanol exposure while the hippocampus is not and that ginseng saponin fraction and ginsenosid es might have a preventive effect against depression of brain ALDH activity by chronic administration of ethanol.