• Korean Journal of Microbiology
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• v.45 no.1
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• pp.17-25
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• 2009

We studied soil components, methane production, the number of methanogens, and T-RFLP patterns dependent on agricultural methods with the change of seasons. There is no regular increase or decrease tendency of the most soil components followed by sampling period. And the water content in soil was higher in October than May. Also a lot of methanogens existed in soil, and acetotrophs were relatively of smaller number than hydogenotrophs and formate utilizing methanogens using MPN (most probable number) enumeration. In the experiment using the formate, it was used from the first week, and only a minute amount was detecte after four weeks. However in the acetate, it was increased until the third week, and after that was consumed. And there was higher methane production for all soil samples which administered with the hydrogen spike. The activity of methanogens was higher in the organic and low-agrichemical agricultural method samples, and the organic agricultural method had high methanogen activity among the other samples. A result of T-RFLP pattern of mcrA gene digested with Sau96I, methanogen community have a little relation with agricultural methods and seasons. This results also agreed to no critical difference the soil components dependent on agricultural methods, but some analytical data have a positive relationship with a agricultural methods. Therefor we could concluded that the comparison study of community for soil bacteria sufficiently could be useful for the microbiological indicator.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.746-752
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• 2005

In this study, the effect of reaction parameters including reaction temperature, time, and pressure on sludge degradation and conversion to intermediates such as organic acids were investigated at low critical wet air oxidation(LC-WAO) conditions. Degradation pathways and a modified kinetic model in LC-WAO were proposed and the kinetics model predictions were compared with experimental data under various conditions. Results in the batch experiments showed that reaction temperature directly affected the thermal hydrolysis reaction rather than oxidation reaction. The efficiencies of sludge degradation and organic acid formation increased with the increase of the reaction temperature and time. The removal of SS at $180^{\circ}C$, $200^{\circ}C$, $220^{\circ}C$ and $240^{\circ}C$ of reaction temperatures and 10 min of reaction time were 52.6%, 68.3%, 72.6%, and 74.4%, respectively, indicating that most organic suspended solids were liquified at early stage of reaction. At $180^{\circ}C$, $200^{\circ}C$, $220^{\circ}C$ and $240^{\circ}C$ of reaction temperatures and 40 min of reaction time, the amounts of organic acids formed from 1 g of sludge were 93.5 mg/g SS, 116.4 mg/g SS, 113.6 mg/g SS, and 123.8 mg/g SS, respectively, and the amounts of acetic acid from 1 g of sludge were 24.5 mg/g SS, 65.5 mg/g SS, 88.1 mg/g SS, and 121.5 mg/g SS, respectively. This suggested that the formation of sludge to organic acids as well as the conversion of organic acids to acetic acid increased with reaction temperature. Based on the experimental results, a modified kinetic model was suggested for the liquefaction reaction of sludge and the formation of organic acids. The kinetic model predicted an increase in kinetic parameters $k_1$ (liquefaction of organic compounds), $k_2$ (formation of organic acids to intermediate), $k_3$ (final degradation of intermediate), and $k_4$ (final degradation of organic acids) with reaction temperature. This indicated that the liquefaction of organic solid materials and the formation of organic acids increase according to reaction temperature. The calculated activation energy for reaction kinetic constants were 20.7 kJ/mol, 12.3 kJ/mol, 28.4 kJ/mol, and 54.4 kJ/mol, respectively, leading to a conclusion that not thermal hydrolysis but oxidation reaction is the rate-limiting step.

• Biomedical Science Letters
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• v.1 no.1
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• pp.45-54
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• 1995

The effect of different fatty acids supplementation on antobody production of Salmonella typhi was studied in ICR mice. Subjects supplemented their diets with $50\mu$g of extracted pig oil(as a saturated fatty acid) and fish oil (as a unsaturated fatty acid) / 2 days for 8 weeks. Blood was collected control and experimental groups of mice after 8 weeks of oil supplementation. The different fatty acids supplementation reduced unsaturated fatty acids composition in mice liver such as $C_{18:3}, \; C_{20:3}\; and\; C_{20:4}\; except\; C_{18:1}\; and\; C_{18:2}/C_{18:0}$ in fish oil and pig oil groups compared to control group. Also, the phagocytic activities of mice macrophages for Candida albicans was reduced by 6% in pig oil group and 9％ in fish oil group than control group. The antigen-stmulated lympocite proliferative response was significantly increased by fatty acid in pig oil group(48％) but 57％ in fish oil group. The different fatty acid supplementation increased antibody production in both experimental groups than control group ; this increase was only significant in pig oil group(1:$2^4$) on mice but not in fish oil group(1:$2^0$) compared to control group(1:$2^0$), however, increased antibody titer in both groups in vitro spleen cell culture supernatant(1:$2^3$ in fish oil group and 1:$2^2$ in pig oil group compared to control group 1:$2^0$). Thus, fish oil supplementation was immunosuppresive agent in macrophage phagocytosis, in-vivo antobody producibilities and lympocyte proliferation but pig oil supplementation was more effective than fish oil in antibody formation in-vivo. We find that antibody producibilities affected by fed on different fatty acids were considered by balance between saturated and unsaturated fatty acid, and $C_{20:3}/C_{20:4}$ ratio. Also, it affected to antigen-stimulated lymphocyte proliferation and macrophage phagocytic activities.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.50 no.1
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• pp.85-93
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• 2024

In this study, we prepared fractions from Cynanchum paniculatum (C. paniculatum) with ethyl acetate and identified the structure and content of paeonol, an indicator substance. Fractions were obtained by sequential solvent fractions using n-hexane, methylene chloride, ethyl acetate, n-butanol, and distilled water, and showed the highest paeonol content in ethyl acetate (EtOAc). The structure of the ethyl acetate fraction (EA) was confirmed by nuclear magnetic resonance (NMR) and the content was determined by high performance liquid chromatography (HPLC) analysis. The antioxidant activity of EA was tested through its ability to scavenge 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and its ability to inhibit nitric oxide (NO) production in RAW 264.7 cells induced by lipopolysaccharide (LPS) was tested for its ability to inhibit NO production in a concentration-dependent manner. Furthermore, MMP-1 production induced by ultraviolet B (UVB) was decreased in a concentration-dependent manner by the EA, and the ability to produce procollagen type-I was increased in a concentration-dependent manner. In addition, as a result of conducting clinical trials using cosmetic formulations containing EA, the effect of improving wrinkles around the eyes was confirmed. Thus, it is expected that Cynanchum paniculatum can be used as a natural functional cosmetic material with antioxidant and anti-aging effects.

• Korean Journal of Plant Resources
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• v.14 no.1
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• pp.24-31
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• 2001

The medicinal constituents contained in Cinidil Rhizoma and Angelicae Radix cultivated in Korea and China, were compared by confirming their qualities. From Cinidil Rhizoma and Angelicae Radix cultivated in Korea and China, butyl phthalide, senkyunolide, and ligustilide etc. phthalides were identified by GC/CMS analysis. Through GC/FID analysis, the senkyunolide content of Cinidil Rhizoma cultivated in Korea was similar to that cultivated in China. The ligustilide content of Ciniail Rhizoma cultivated in Korea was more than that cultivated in China, except for one cultivated at Ankuk province. In the case of Angelicae Radix, the ligustilide content of that cultivated in Korea was more than one cultivated at Yeungil province in China. As for quality, Cinidil Rhizoma and Angelicae Radix cultivated in Korea were better than those cultivated in China since Chinese products possessed more butilidene phthalide photo-decomposed from ligustilide, caused by long storage during the circulation processes, than that of the domestic products.

• Korean Journal of Materials Research
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• v.7 no.11
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• pp.957-963
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• 1997

PVC 핏치를 산소분위기에서 안정화시킬 때 발생되는 화학반응 기구를 열중량 분석 및 FT-IR을 이용하여 규명하였다. PVC 핏치를 안정화시킬 \ulcorner 초기에 가속화현상이 이러나서 핏치내에 반응성이 강한 메칠기(-CH/ sub 3/)나 메칠렌기(-CH$_{2}$-)등이 산소와 반응하여 카보닐기(C=O)를 생성하면서 급격한 무게증가 현상이 발생하였다. 이때의 생성물들은 알데히드(aldehyde), 케톤(ketone), 알코올(alcohol)이며, 물 (H$_{2}$O)이 부산물로 발생된다. 이 가속화 현상에 의해 핏치내의 메칠기와 메칠렌기는 안정화 초기단계에서 대부분 산화되어 없어졌다. 안정화시간이 길어짐에 따라 생성된 알데히드나 일차 알코올의 산화가 발생하여 카르복실산(carboxylic acid)을 생성하고, 에테르 결합도 생성되었다. 이때에도 무게증가 현상이 발생하지만, 초기의 급격한 무게증가와는 달리 그 증가속도가 느리고, 시간이 경과함에 따라 증가속도는 더욱 느려졌다. 그리고, 안정화온도가 높고 안정화시간이 긴경우에는,카르복실산들의 탈수반응으로 인한 방향족 무수화물(aromatic anhydride)이 생성되었다. 29$0^{\circ}C$에서 24시간 안정화시킨 경우, 무게감소가 발생했는데, 이것은 카르복실산의 탈카르복실화(decarboxylation)반응에 의해 CO$_{2}$가 발생되었기 때문이다. 그리고, 안정화 온도가 높을수록 안정화에 무게증가의 최대값과 방향족 무수화물이 발생되는 무게증가 값이 작아지고, 안정화 초기단계에서 나타나는 가속화 현상의 구간도 짧아졌다.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.51-58
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• 1996

The rearrangement of [(ethoxycarbonyl)phenylaminomethyl]phenylcarbamic acid ethyl esters(N-benzyl compounds) to methylenediphenyldiurethanes(MDU) in sulfuric acid, sulfuric acid-absolute ethanol solvent system, and sulfuric acid-nitrobenzene solvent system, and boron trifluoride at $90^{\circ}C$ was studied. The production of MDU was the highest in sulfuric acid-nitrobenzene system giving 64% MDU yield, of which 58% was 4,4'-MDU. The simultaneous condensation of EPC and formaldehyde and rearrangement to MDU were studied in the presence of different amounts of sulfuric acid, trifluoroacetic acid, and boron trifluoride at $70^{\circ}C$. Though 17mmol of sulfuric acid with 30mmol of EPC produced the highest MDU, the MDU yield was much lower than that from separate condensation and rearrangement reaction.

• Korean Journal of Optics and Photonics
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• v.30 no.3
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• pp.87-93
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• 2019

Phase screens are widely used to simulate the effects of atmospheric turbulence on the phase fluctuations of a light beam. We compare three sampled-based phase-screen-generation methods (the fast-Fourier-transform, subharmonic, and covariance-matrix methods), in terms of accuracy and simulation time. We show that the covariance method generates the phase screens most accurately, with simulation time comparable to the other sampled-based methods.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.319-325
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• 2010

The purpose of this study is to investigate the soil compositions, methane production, the number of methanogens, and the community structure of methanogens in rice paddy soils and dry field farming soils in the summer and autumn seasons. As a result of the analysis of soil compositions, any regular tendency to increase or decrease has not been found in most soil samples due to the change of seasons. It has also been found that more methanogens exist in the rice paddy soil that utilize organic farming practices and emptiness farming practices than in the dry field farming soil. The fewer numbers of methanogens utilizing the acetate have been found than those of the methanogens utilizing the hydrogen or the formate. In an experiment of methane production, the methanes increased for two weeks when the acetate was added, but they continued to increase for seven weeks more when the formate and the hydrogen were added. In the phylogenetic analysis using the mcrA gene, the methanogens had diverse clusters in the rice paddy soil, whereas the methanogens were concentrated only in a few clusters in the dry field farming soil.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.39-45
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• 2002

It was found that the peptides originated from the hydrolysates of silk fibroin have in vitro immunostimulating effects in murine macrophage RAW264.7 cells. The stimulation effects on nitric oxide (NO) production resulted from treatments of acid or enzymatic hydrolysates were measured. The silk fibroin preparation isolated from cocoon was most efficiently digested by acid hydrolysis. Even though the sole treatment of acid hydrolysate stimulated the NO production in dose-dependent pattern, a part of its activity was found to be caused by the contaminated endotoxin, LPS. When each endotoxin-free hydrolysates obtained by filtering it through an ultrafiltration membrane of molecular weight (MW) cut-off 10,000 to eliminate LPS was used, the peptic hydrolysate with lowest degree of hydrolysis showed the highest activity. The fractions of peptic hydrolysate with MW ranges of 1,000∼10,000, 500∼1,000 and below 500 also showed a higher MW-higher activity correlation. From the analyses of amino acid composition of each hydrolysate, it was found that the contents of arginine, lysine, alanine and glycine residues affected the activity level of hydrolysate. The results of this study showed a possibility of utilizing fibroin as a source for immunostimulating (chemopreventive) functional peptides.