• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.630-631
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• 2000

Sugar esters are produced by transesterification of fatty acids and sugars in organic solvent media. Chromatographic separation of sugar esters and fatty acids was investigated. $C_{18}$ column($3.9{\times}300mm$) was used in the chromatography experiment. The effect of flow rate, column temperature, and sample loading on the charateristics of chromatogram was studied. Sugar esters and fatty acids tested in this study was successfully separated with a high resolution.

• Journal of Life Science
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• v.9 no.6
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• pp.737-742
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• 1999

The extremely halophilic archaebacterium Haloarcular sp. EH-1 was isolated from solar salts. Haloarcular sp. EH-1 accumulated poly(3-hydroxyalkanoate) (PHA) as intracellular granules. PHA production in batch culture have been studied. The PHA was identified as poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHB/HV) of 3-hydroxybutyric acid and 3-hydroxyvaleric acid by the analysis of GC, IR and NMR. The melting temperature of PHB/HV was 152.46$^{\circ}C$, viscosity was 1.25 ㎗/g, and molecular weight was $1.44 X 10^5.$

• Journal of Food Hygiene and Safety
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• v.9 no.4
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• pp.185-189
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• 1994

This study was to investigate time-dependent degradation process under various pH condition for organophosphorus(org-p) insecticides, namely Demeton-s-methyl, diazinon, Parathion, Phenthoate, and EPN in several waters. They were analysed by GC-FTD according to standard methods for the examination of water and wastewater. In pH=4, diazinon showed disappearance after 14 days in chromatogram. In pH=11, org-p insecticides were almost degradable after 7 days. In this condition, effect of pH on degradation process was greater than of light. In pH=7, org-p insecticides persisted residues after 112 days except Demeton-s-methyl. In BOD5 120, 250 ppm and domestic water, org-p insecticides showed also rapid degradation process.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.31-36
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• 2001

Optimal operation in chromatography is needed to save operation time and the solvent used in multiple chromatographic runs. To this end, many simulation studies of chromatography process have been performed. The relationship between the distribution coefficient and the ionic strength is important in gradient elution ion chromatography. Experimental runs and computer simulations were carried out under linear gradient elution condition in order to compare the experiments and the simulation. Experiments were performed with formic acid under isocratic conditions to determine the simulation equation parameters. Computer simulation was based on three equations which related distribution with ionic strength as follows; K=${\alpha}$I(sup)-${\beta}$, K=A+BI+Cl$^2$and K=y(sub)0+A$_1$$.$e(sup)(-I/m$_1$). The effects of gradient slope on the chromatograms are discussed, and good agreement between the experimental and the simulated results is shown.

• Analytical Science and Technology
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• v.5 no.3
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• pp.339-343
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• 1992

The content of lysophosphatidyl choline (LPC) in wheat starch lipids from six cultivar representing three classes of wheat was determined by a high performance liquid chromatography using UV-detection (HPLC-UV). The HPLC-UV assay had a sensitivity of LPC concentrations above $5{\mu}g/50{\mu}l$ and required 80 minutes per chromatogram.

• Journal of Microbiology and Biotechnology
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• v.3 no.4
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• pp.270-276
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• 1993

We characterized the character impact compounds of flavors of the fermented Korean soy sauce manufactured with both the traditional and the improved Meju made with different strains. The whole flavor samples were obtained by extracting each volatile flavor phase from both the traditional and the improved soy sauce. To get more detailed information, each whole volatile flavor was further fractionated into the basic, acidic, phenolic and neutral fractions. Each separated peak from the whole and fractionated flavor samples on gas chromatogram was identified by GC/MS and Kovat s retention index, and likewise the aroma of each peak was investigated by a sniffing test with the exercised panel. We were able to identify 15 groups of ingredients with the characteristic soy sauce aroma from the soy sauce made with the traditional Meju and 6 groups from the soy sauce manufactured with the improved Meju made with Aspergillus oryzae. The character impact compounds the two soy sauces were different from each other.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.329-333
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• 2005

ACE inhibition activity of peptides was measured after 2 months of storage at $4^{\circ}C$ under condition of pH 6.0, 6.5, 7.0, 7.5, 8.0. and the ACE inhibitory activity were changed only slightly. After 2 months of chilled storage ($4^{\circ}C$), no dramatic change and significance was found. This indicates that acidic, neutral, weak alkali conditions did not affect ACE inhibitory activity of those peptides. Among peptide 1134, 1152, and 1155, peptides from thermolysin + protease A hydrolysates, inhibition activity of peptide 1134 and 1152 was decreased significantly at $60^{\circ}C$, however, they showed stable inhibition activity from $70^{\circ}C$ to $100^{\circ}C$ (P<0.001). Also, chromatogram of peptide 1134, 1152, and 1155 was shown that retention time of peptide of $60^{\circ}C$ was not correspond to the retention time of the rest of peptides. This indicated that temperature may change the inhibitory activity and profile of peptides.

• Journal of Ginseng Research
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• v.10 no.2
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• pp.187-192
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• 1986

Activity of endogenous growth regulator in 4th year Panax ginseng root was investigated by second leaf sheath test of rice seedling and paper chromatogram of a acidic fraction of methanol extract before (March 28) and after (May 9) emergence of root bud, at the late season (Sept.4) and after leaf fall (November 11). GA$_3$ and ABA were used as reference. According to paper and high performance liquid chromatography of samples and authentic growth regulators the presence of insole acetic acid (IAA), gibberellic acid (GA$_3$) and abscisic acid (cis and trans ABA) was confirmed. These three regulators appeared to consist of major system though the existence of other regulators could not be ruled out. IAA activity seemed little changed through out the seasons. GA activity decreased in the later stages while ABA activity increased.

• Elastomers and Composites
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• v.51 no.1
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• pp.63-67
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• 2016

Poly(ethylene-co-vinyl acetate) (EVA) was pyrolyzed to eliminate acetic acid of VA unit using off-line pyrolysis, and the deacetylated EVA was analyzed infrared spectroscopy (IR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). EVA film for deacetylation was prepared by solution casting on aluminum foil and it was pyrolyzed at low temperature of $300^{\circ}C$ in the off-line pyrolysis apparatus. After deacetylation, carbon-carbon double bond (C=C) was formed by 1,2-elimination of the VA unit in the EVA backbone. Most of C=C bonds were trans-1,4-unit and 1,2-unit was also observed. Presence of the 1,2-unit in deacetylated EVA indicates that terminal or branch VA units exist in the raw EVA. Py-GC/MS chromatogram of deacetylated EVA displayed much smaller acetic acid and much more abundant other pyrolysis products than that of raw EVA, which means that the pyrolysis efficiency and separation condition were improved.

• The Korean Journal of Physiology
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• v.19 no.2
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• pp.215-225
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• 1985

흰쥐의 태아에서 ACTH의 분비양상을 알아보기 위하여, 태아의 제태일수에 따라 혈장 및 뇌하수체 전엽에서 여러 분자형태의 ACTH를 방사면역측정법으로 측정하였다. 태아의 혈장 ACTH농도는 제태 19일에서 가장 높았으며 그후 계속 감소하여 출생후 1주에서 가장 낮은 값을 보였다. 출생 1주후부터 ACTH농도는 다시 증가하기 시작하여 출생후 21일에서는 거의 성체의 값에 도달하였다. 측정된 ACTH는 chromatogram상에서 항상 3가지 peak가 나타났다. 즉 'big'형 ('big' ACTH, $MW\approx44,000$), 'intermediate'형 ('intermediate' ACTH, $MW\approx13,000$)및 'little'형 ('little' ACTH, $MW\approx4,500$)으로 구분되었다. 임신말기 (제태기간 17일에서 21일 사이)에서 태아 혈장의 ACTH는 'little'형의 비율이 증가한 반면 'big'형의 비율은 감소하였다. 그러나 뇌하수체 전엽에서 분비된 ACTH는 3가지 형이 같은 비율이었다. 뇌하수체 전엽에서 분리한 'big'형의 ACTH를 시침관내에서 trypsin을 처리한 결과 'intermediate'형과 little'형이 출현하였다. 이 결과로 미루어 태아 흰쥐의 뇌하수체에서 분비된 ACTH가 순환도증 다른 형으로 전환될 수 있음이 시사된다.