• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.213-218
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• 2017

The objective was to examine the antifungal activity of Pinus densiflora extract for the control of turfgrass fungal diseases. Antifungal activities of the various fractions of n-hexane, methylene chloride (Ch), ethyl acetate (EtOAc), and n-butanol from P. densiflora were evaluated against Rhizoctonia solani AG1-1B, R. solani AG2-2IV, Sclerotinia homoeocarpa, R. cerealis, Pythium spp., and Colletotrichum graminicola. The Ch and EtOAc fractions showed antifungal activity against Pythium sp. and C. graminicola in paper disc assay. The effective concentration to produce 50% mycelial inhibition ($EC_{50}$) using five discriminatory concentrations of pinosylvin (1) from the Ch fraction of P. densiflora was evaluated on R. solani AG1-1B, R. solani AG2-2IV, R. cerealis, and S. homoeocarpa. S. homoeocarpa showed the highest sensitivity with the lowest mean $EC_{50}$ value ($8.426{\mu}g/mL$) among the four pathogens. Among the three Rhizoctonia pathogens, R. cerealis had the highest mean $EC_{50}$ value ($99.832{\mu}g/mL$) and R. solani AG2-2IV, with the lowest sensitivity, had the lowest $EC_{50}$ value ($39.696{\mu}g/mL$). These results suggested that pinosylvin (1) from P. densiflora could be a valuable lead compound in the improvement of a novel antifungal agent.

• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.969-978
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• 2014

The aprE2 gene with its prosequence from Bacillus subtilis CH3-5 was overexpressed in Escherichia coli BL21(DE3) by using plasmid pET26b(+). After IPTG induction, active and mature AprE2 was produced when cells were grown at $20^{\circ}C$, whereas inactive and insoluble enzyme was produced in a large amount when cells were grown at $37^{\circ}C$. The insoluble fraction was resuspended with 6 M guanidine-HCl and dialyzed against 2 M Tris-HCl (pH 7.0) or 0.5 M sodium acetate (pH 7.0) buffer. Then active AprE2 was regenerated and purified by a Ni-NTA column. Purified AprE2 from the soluble fraction had a specific activity of $1,069.4{\pm}42.4U/mg$ protein, higher than that from the renatured insoluble fraction. However, more active AprE2 was obtained by renaturation of the insoluble fraction. AprE2 was most stable at pH 7 and $40^{\circ}C$, respectively. The fibrinolytic activity of AprE2 was inhibited by PMSF, but not by EDTA and metal ions. AprE2 degraded $A{\alpha}$ and $B{\beta}$ chains of fibrinogen quickly, but not the ${\gamma}$-chain. AprE2 exhibited the highest specificity for N-succinyl-Ala-Ala-Pro-Phe-pNA. The $K_m$ and $k_{cat}/K_m$ of AprE2 was 0.56 mM and $3.10{\times}10^4S^{-1}M^{-1}$, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.3
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• pp.197-205
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• 2013

An in vitro study was conducted to determine the effects of defaunation (removal of protozoa) and forage sources (rice straw, ryegrass and tall fescue) on ruminal fermentation characteristics, methane ($CH_4$) production and degradation by rumen microbes. Sodium lauryl sulfate, as a defaunation reagent, was added into the mixed culture solution to remove ruminal protozoa at a concentration of 0.375 mg/ml. Pure cellulose (0.64 g, Sigma, C8002) and three forage sources were incubated in the bottle of culture solution of mixed rumen microbes (faunation) or defaunation for up to 24 h. The concentration of ammonia-N was high under condition of defaunation compared to that from faunation in all incubations (p<0.001). Total VFA concentration was increased at 3, 6 and 12 h (p<0.05~p<0.01) but was decreased at 24 h incubation (p<0.001) under condition of defaunation. Defaunation decreased acetate (p<0.001) and butyrate (p<0.001) proportions at 6, 12 and 24 h incubation times, but increased propionate (p<0.001) proportion at all incubation times for forages. Effective degradability of dry matter was decreased by defaunation (p<0.001). Defaunation not only decreased total gas (p<0.001) and $CO_2$ (p<0.01~0.001) production at 12 and 24 h incubations, but reduced $CH_4$ production (p<0.001) at all incubation times for all forages. The $CH_4$ production, regardless of defaunation, in order of forage sources were rice straw > tall fescue > ryegrass > cellulose (p<0.001) up to 24 h incubation.

• Journal of Conservation Science
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• v.32 no.3
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• pp.321-331
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• 2016

Textiles damage caused by acetaldehyde($CH_3CHO$) is not clear as compared to other materials. Total 20 specimens were prepared using 4 different materials (silk, cotton, ramie, hemp) after dyed with 4 colors (undyed, red, yellow, blue, black). The specimens were exposed to $CH_3CHO$ gas in the test chamber. First, textile specimens' damage by differert concentration of acetaldehyde(0.1, 0.5, 1, 10, 100, 500, 1000 ppm) was tested. Second, accelerared damage to the textile specimens were tested according to the temperature and humidity conditions at the damage levels. Third, damage of deliberately degraded textile specimens were examined at the damage levels. After the exposure, optical, chemical, and physical evaluation was carried out. As a result, at 1000 ppm/day, the color difference of cotton_yellow has increased. At the condition of $25^{\circ}C-80%$, $30^{\circ}C-50%$, $30^{\circ}C-80%$, the color difference of yellow specimens has increased and grey scale rating has decreased. At $30^{\circ}C-80%$, acetate of cotton_undyed increased and the pH of silk_undyed decreased. In the case of deliberately degraded textile specimens, actetate concentration of black specimens increased. In conclusion, damage to the traditional fabric by acetaldehyde is not impact. However, it is expected that yellow specimens will be bleach and black specimens' actetate concentration will be increase.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.10
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• pp.1381-1388
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• 2012

An in vitro experiment was conducted to examine the effects of defaunation (removal of protozoa) on ruminal fermentation characteristics, $CH_4$ production and degradation by rumen microbes when incubated with cereal grains (corn, wheat and rye). Sodium lauryl sulfate as a defaunation reagent was added into the culture solution at a concentration of 0.000375 g/ml, and incubated anaerobically for up to 12 h at $39^{\circ}C$. Following defaunation, live protozoa in the culture solution were rarely observed by microscopic examination. A difference in pH was found among grains regardless of defaunation at all incubation times (p<0.01 to 0.001). Defaunation significantly decreased pH at 12 h (p<0.05) when rumen fluid was incubated with grains. Ammonia-N concentration was increased by defaunation for all grains at 6 h (p<0.05) and 12 h (p<0.05) incubation times. Total VFA concentration was increased by defaunation at 6 h (p<0.05) and 12 h (p<0.01) for all grains. Meanwhile, defaunation decreased acetate and butyrate proportions at 6 h (p<0.05, p<0.01) and 12 h (p<0.01, p<0.001), but increased the propionate proportion at 3 h, 6 h and 12 h incubation (p<0.01 to 0.001) for all grains. Defaunation increased in vitro effective degradability of DM (p<0.05). Production of total gas and $CO_2$ was decreased by defaunation for all grains at 1 h (p<0.05, p<0.05) and then increased at 6 h (p<0.05, p<0.05) and 12 h (p<0.05, p<0.05). $CH_4$ production was higher from faunation than from defaunation at all incubation times (p<0.05).

• Analytical Science and Technology
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• v.29 no.5
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• pp.219-224
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• 2016

불산 중 극미량 음이온의 고상추출과 이온크로마토그래프를 이용한 고감도 분석법이 개발되었다. 불산 중 불소이온이 고상에 의해 제거하였고 이어서 음이온 (F⁻, CH₃COO⁻, Cl⁻, Br⁻, NO₃⁻, PO₄³⁻, SO₄²⁻)들이 이온크로마토그래프를 이용하여 연속적으로 분리하였다. 고상 추출법에 영향을 주는 각 인자들 (흡착제의 선택, 시료의 부피 및 pH, 용출 용액과 용출용액의 부피)을 결정하였으며 그 결과 흡착제로서 Oasis WAX 컬럼이 가장 우수하였고 1.0 mL의 시료부피, 용출용액으로 50 mM 초산암모늄염 5 mL가 분리능에서 가장 우수하였다. 개발한 방법에 의한 음이온 (Cl⁻, Br⁻, NO₃⁻, PO₄³⁻, SO₄²⁻)들의 방법검출한계는 25 % 불산용액 (w/w) 중에 0.04~0.30 µg/L의 범위를 보였고 정밀도는 20.0와 40.0 µg/L의 농도에서 5 % 이내를 보였다. 한 제조회사에 의한 25 % 불산 중 음이온의 4.2에서 47.5 µg/L의 범위로 모두 검출되었다. 이 방법은 시험절차가 간단하고, 재현성 및 감도가 좋아서 반도체회사에서 불산 중 음이온 불순물을 정도 관리하는데 매우 유용한 방법이 될 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1562-1570
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• 2014

The effects of Lactobacillus mucosae (L. mucosae), a potential direct fed microbial previously isolated from the rumen of Korean native goat, on the rumen fermentation profile of brewers grain were evaluated. Fermentation was conducted in serum bottles each containing 1% dry matter (DM) of the test substrate and either no L. mucosae (control), 1% 24 h broth culture of L. mucosae (T1), or 1% inoculation with the cell-free culture supernatant (T2). Each serum bottle was filled anaerobically with 100 mL of buffered rumen fluid and sealed prior to incubation for 0, 6, 12, 24, and 48 h from which fermentation parameters were monitored and the microbial diversity was evaluated. The results revealed that T1 had higher total gas production (65.00 mL) than the control (61.33 mL) and T2 (62.00 mL) (p<0.05) at 48 h. Consequently, T1 had significantly lower pH values (p<0.05) than the other groups at 48 h. Ammonia nitrogen ($NH_3$-N), individual and total volatile fatty acids (VFA) concentration and acetate:propionate ratio were higher in T1 and T2 than the control, but T1 and T2 were comparable for these parameters. Total methane ($CH_4$) production and carbon dioxide ($CO_2$) were highest in T1. The percent DM and organic matter digestibilities were comparable between all groups at all times of incubation. The total bacterial population was significantly higher in T1 (p<0.05) at 24 h, but then decreased to levels comparable to the control and T2 at 48 h. The denaturing gradient gel electrophoresis profile of the total bacterial 16s rRNA showed higher similarity between T1 and T2 at 24 h and between the control and T1 at 48 h. Overall, these results suggest that addition of L. mucosae and cell-free supernatant during the in vitro fermentation of dried brewers grain increases the VFA production, but has no effect on digestibility. The addition of L. mucosae can also increase the total bacterial population, but has no significant effect on the total microbial diversity. However, inoculation of the bacterium may increase $CH_4$ and $CO_2$ in vitro.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.330-332
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• 2013

소 분위기에서 플라즈마 표면 처리의 경우 기판 표면에 존재하는 수소와 탄소 유기물들이 산소와 반응하여 $H_2O$와 $CO_2$ 등으로 제거되며 표면에 오존 결합을 유도하여 표면 에너지를 증가시키는 것으로 알려져 있다. ZnO 나노구조물을 성장시키는 방법으로는 MOCVD (Metal-Organic Chemical Vapor Deposited), PLD (Pulsed Laser Deposition), VLS (Vapor-Liquid-Solid), Sputtering, 습식화학합성법(Wet Chemical Method) 방법 등이 있다. 그중에서도 습식화학합성법은 쉽게 구성요소를 제어할 수 있고, 저비용 공정과 낮은 온도에서 성장 가능하며 플렉서블 소자에도 적용이 가능하다. 그러므로 본 연구에서는 플라즈마 표면처리에 따라 표면에너지를 변화하여 습식화학합성법으로 성장시킨 ZnO nanorods의 밀도를 제어하고 photolithography 공정 없이 패터닝 가능성을 유 무를 판단하는 연구를 진행하였다. 기판은 Si wafer (100)를 사용하였으며 세척 후 표면에너지 증가를 위한 플라즈마 표면처리를 실시하였다. 분위기 가스는 Ar/$O_2$를 사용하였으며 입력전압 400 W에서 0, 5, 10, 15, 60초 동안 각각 실시하였다. ZnO nanorods의 seed layer를 도포하기 위하여 Zinc acetate dehydrate [Zn $(CH_3COO)_2{\cdot}2H_2O$, 0.03 M]를 ethanol 50 ml에 용해시킨 후 스핀코팅기를 이용하여 850 RPM, 15초로 5회 실시하였으며 $80^{\circ}C$에서 5분간 건조하였다. ZnO rods의 성장은 Zinc nitrate hexahydrate [$Zn(NO_3)_2{\cdot}6H_2O$, 0.025M], HMT [$C6H_{12}N_4$, 0.025M]를 deionized water 250 ml에 용해시켜 hotplate에 올리고 $300^{\circ}C$에서 녹인 후 $200^{\circ}C$에서 3시간 성장시켰다. ZnO nanorods의 성장 공정은(Fig. 1)과 같다. 먼저 플라즈마 처리한 시편의 표면에너지 측정을 위해 접촉각 측정 장치[KRUSS, DSA100]를 이용하였다. 그 결과 0, 5, 10, 15, 60 초로 플라즈마 표면 처리했던 시편이 각각 Fig. l, 2와 같이 $79^{\circ}$, $43^{\circ}$, $11^{\circ}$, $6^{\circ}$, $7.8^{\circ}$로 측정되었으며 이것을 각각 습식화학합성법으로 ZnO nanorods를 성장 시켰을 때 Fig. 3과 같이 밀도 차이를 확인할 수 있었다. 이러한 결과를 바탕으로 기판의 표면에너지를 제어하여 Fig. 4와 같이 나타나며 photolithography 공정없이 ZnO nanorods를 패터닝을 할 수 있었다. 본 연구에서는 플라즈마 표면 처리를 통하여 표면에너지의 변화를 제어함으로써 ZnO nanorods 성장의 밀도 차이를 나타냈었다. 이러한 저비용, 저온 공정으로 $O_2$, CO, $H_2$, $H_2O$와 같은 다양한 화학종에 반응하는 ZnO를 이용한 플렉시블 화학센서에 응용 및 사용될 수 있고, 플렉시블 디스플레이 및 3D 디스플레이 소자에 활용 가능하다.

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.871-877
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• 1994

Most of the aromatic nitro compounds were reduced to amines in high yield by transfer of hydrogen from 4-vinyl cyclohexene to the substrate via palladium catalyst. The usefulness of the method is not affected by the presence of a variety of other functional groups such as -OH, $-OCH_3$, $-CH_3$, $-CO_2H$, and -Cl, except for halogen which is removed during hydrogenation. The reduction of ortho-substituted nitrobenzene such as o-nitrotoluene, o-nitrophenol, o-nitroanisole was slower than the para isomer. Typically, the nitro compound is refluxed in ethanol with a large exess of 4-vinylcyclohexene in the presence of Pd-C catalyst. Under the above conditions, p-nitrobenzaldehyde, p-nitrobenzyl alcohol, and p-nitrobenzyl acetate were reduced to p-toluidine.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.5
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• pp.603-613
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• 2011

The collection of $PM_{10}$ and $PM_{2.5}$ samples was made at Gosan site of Jeju Island. Their ionic compositions of both inorganic and organic phases were then analyzed to examine their acidification and neutralization characteristics in atmospheric aerosols. The mass concentrations of $PM_{10}$ and $PM_{2.5}$ at Gosan site were $37.6{\pm}20.1$ and $22.9{\pm}14.3{\mu}g/m^3$, respectively, showing the content ratio of $PM_{2.5}$ to $PM_{10}$ as 61.0%. In the evaluation of ionic balance, the correlation coefficients (r) between the sums of cationic and anionic equivalent concentrations were excellent with 0.982 ($PM_{10}$) and 0.991 ($PM_{2.5}$). The concentration ratios of $PM_{2.5}/PM_{10}$ derived for nss-$SO_4^{2-}$, $NO_3^-$, and $NH_4^+$ were 0.94, 0.56, and 1.02, respectively, indicating the relative dominance of fine fractions. The acidifying capacity of inorganic anions ($SO_4^{2-}$ and $NO_3^-$) in $PM_{10}$ and $PM_{2.5}$ were 96.5% and 97.3%, while those of organic anions ($HCOO^-$ and $CH_3COO^-$) in each fraction were 2.9% and 2.0%, respectively. On the other hand, the neutralizing capacity of $PM_{10}$ and $PM_{2.5}$ by $NH_3$ were 72.8% and 82.3%, while their $CaCO_3$ counter parts were 22.5% and 13.3%, respectively.