• Microbiology and Biotechnology Letters
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• v.25 no.1
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• pp.44-50
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• 1997

$\beta $-Glucosidase (EC 3.2.1.21) was purified from Aspergillus niger SFN-416 by a sequential process of ammonium sulfate precipitation, Sepadex G-100 and DEAE-Sephacel column chromatography. Molecular weight of the enzyme was 46, 000 daltons. The K$_{m}$ and V$_{max}$ values for PNPG were 0.67 mM and 25 moles/ml $\cdot $min., respectively. The optimum pH and temperature of the enzyme activity were 3.5 and 58$\circ $C, respectively. The enzyme activity was decreased by addition of metal ions, and increased by addition of metanol, ethanol, isopropanol and 1-butanol at a concentration of 10% (v/v). Stability of the enzyme was increased by addition of isopropanol and 1-butanol at a concentration of 10% (v/v).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.998-1001
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• 2002

Some diphenoquinone(DQ) derivatives were synthesized and electron drift mobility of them measured by Time of Flight (TOF) apparatus. Electron drift mobility of DQ series is linearly on increasing electric filed dependent. Drift mobility of ADQ mixture is $1{\times}10^{-6}cm^2/V{\cdot}s$ at $1.1{\mu}m$ thickness and $8.1{\times}10^4V/cm$.

• Journal of the Korean Chemical Society
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• v.36 no.6
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• pp.894-905
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• 1992

Dioxygen binding and homogeneous catalytic oxidation of hydrazobenzene were investigated by employing tetradentate Schiff base Cobalt(II) complexes such as Co(II)(SED)$(Py)_2$, Co(II)(SOPD)$(Py)_2$ and Co(II)(SND)$(Py)_2$ in saturated oxygen methanol solvent. The major product of hydrazobenzene ($H_2$AB) oxidation by catalysts of superoxo type [Co(III)(SED)(Py)$O_2$] and [Co(III)(SOPD)(Py)$O_2$] complexes are trans-azobenzene (t-AB) and rate constants k for oxidation reaction was 7.692 ${\times}$ $10^{-2}$ M/sec for [Co(III)(SED)(Py)$O_2$] and 5.076 ${\times}$ $10^{-2}$ M/sec for [Co(III)(SOPD)(Py)$O_2$]. But cis-azobenzene (c-AB) are obtained as a major product with ${\mu}$-peroxo type [Co(III)(SED)(Py)]$_2O_2$ catalyst, and rate constant k is 1.266 ${\times}$ $10^{-2}$ M/sec. The rate constants of oxidation reaction has been studied spectrophotometrically and the rate law established. A mechanism involving a intermediate activated complexes of catalyst, hydrazobenzene and oxygen has been proposed. $H_2$AB + Co(II)(Schiff base)$(Py)_2$ + $O_2$ ${\rightleftharpoons}_{MeOH}^K$ Co(III)(Schiff base)(Py)$O_2$${\cdot}$$H_2$AB + Py $\longrightarrow^k$ Co(II)(Schiff base)$(Py)_2$ + t-AB + $H_2O_2$(Scchiff base : SED and SOPD). $H_2$AB + 2Co(II)(SND)$(Py)_2$ + $O_2$ ${\rightleftharpoons}_{MeOH}^K$ [Co(III)(SND)(Py)]$_2O_2$${\cdot}$H_2$AB + 2Py ${\longrightarrow}^k$ (Co(II)(SND)$(Py)_2$ + c-AB + $H_2O_2$.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.370-373
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• 1998

Fumigation by combination of methyl bromide/phosphide ($MB/PH_3$) was much more effective in disinfestating the rose insect pests (Aphis gossypii, Tetranychus urticae, and Frankliniella occidentalis) than that by individual MB or $PH_3$. Fumigation for 2 hours in the chamber using ;$MB/PH_3$ at the concentration of $10/3g{\cdot}m^{-3}$ brought about 91.3% and 100% mortality in aphids and thrips, respectively. Fumigation for 3 hrs using ;$MB/PH_3$ at the concentration of 5/3 or $7/3g{\cdot}m^{-3}$ showed over 96% mortalities in mites and thrips as well as no phytotoxicity symptoms, e.g. tip burn or bent neck, in cut roses, while mortalities of mites and thrips were not influenced by increasing $CO_2$ concerntration from 0.03% to 10% or decreasing $O_2$ concentration up to 15% in fumigation chamber.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.476-485
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• 2005

In this study, abiotic transformation of TNT reduction products via oxidative-coupling reaction was investigated using Mn oxide. In batch experiments, all the reduction products tested were completely transformed by birnessite, one of natural Mn oxides present in soil. Oxidative-coupling was the major transformation pathway, as confirmed by mass spectrometric analysis. Using observed pseudo-first-order rate constants with respect to birnessite loadings, surface area-normalized specific rate constants, $k_{surf}$, were determined. As expected, $k_{surf}$ of diaminonitrotoluenes (DATs) ($1.49{\sim}1.91\;L/m^2{\cdot}day$) are greater about 2 orders than that of dinitroaminotoluenes (DNTs) ($1.15{\times}10^{-2}{\sim}2.09{\times}10^{-2}\;L/m^2{\cdot}day$) due to the increased number of amine group. In addition, by comparing the value of $k_{surf}$ between DNTs or DATs, amino group on ortho position is likely to be more preferred for the oxidation by birnessite. Although cross-coupling of TNT in the presence of various mediator compounds was found not to be feasible, transformation of TNT by reduction using $Fe^0$ followed by oxidative coupling using Mn oxide was efficient, as evaluated by UV-visible spectrometry.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.21-21
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• 2018

본 연구는 북방계 식물에 속하는 두메우드풀[Woodsia ilvensis (L.) R.Br.]의 전엽체 증식 및 포자체 형성을 위한 적정방법을 구명하고자 수행되었다. 식물재료는 경상북도 의성군 일대에서 채취한 후 청주의 일반하우스에 이식하여 재배하였다. 포자 성숙기인 8월에 채종하여 발아시켰으며, 포자로부터 획득한 전엽체를 8주간 계대하면서 실험재료로 사용하였다. 전엽체 300mg을 메스로 다진 후 배지농도 및 종류(Knop, 1/4, 1/2, 1 및 2MS)를 달리하여 8주간 배양하였다. 배양실의 온도는 $25{\pm}1.0^{\circ}C$, 광도는 $30{\pm}1.0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(16/8h)로 조절되었다. 연구의 결과, 배지구성물질의 농도가 높았던 2MS배지에서 전엽체의 생체중이 12.4g으로 41배 증가하여 가장 높은 증식율을 나타냈다. 또한 배지구성물질의 농도가 적을수록 생체중의 증가폭도 함께 감소하는 경향을 보였다. 포자체 형성에 적합한 토양조건을 확인하고자, 원예상토, 피트모스, 펄라이트 및 마사토의 비율을 달리한 5종류의 혼합토양을 조성하여 사각분($7.5{\times}7.5{\times}7.5cm$)에 충진하였다. 다음으로 전엽체 1g을 핸드블랜더로 10초간 분쇄 후 충진된 사각분 위에 고르게 분주하여 14주간 재배하였다. 재배환경은 온도 $25{\pm}1.0^{\circ}C$, 광도 $43{\pm}2.0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(16/8h) 및 습도 $72{\pm}2.0%$로 조절되었다. 지베렐린 수용액이 포자체 형성에 미치는 영향을 조사하고자, 선행연구에서 선발된 토양조건을 기준으로 침지농도(0, 50, 100, $200mg{\cdot}L^{-1}$)를 조절하여 1시간 침지 후 상기와 동일한 방법으로 재배하였다. 연구의 결과, 원예상토와 펄라이트 또는 마사토를 2:1(v:v)로 혼용한 토양에서 사각분 당 109.5, 128.8개의 포자체가 형성되었다. 한편, 피트모스가 첨가된 처리는 포자체의 형성이 억제되는 경향을 나타냈다. 지베렐린 50과 $100mg{\cdot}L^{-1}$ 수용액에 침지한 처리에서 무처리에 비해 많은 사각분 당 각 177.0, 181.7개의 포자체가 형성되었으며, 생육도 양호하였다.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1545-1547
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• 2000

The mechanical and electrical properties of the hot-pressed and annealed $\beta$-Sic-$TiB_2$ electroconductive ceramic composites were investigated as function of the liquid forming additives of $Al_{2}O_{3}+Y_{2}O_3$. Phase analysis of composites by XRD revealed $\alpha$-SiC(6H), $TiB_2$, and YAG($Al_{5}Y_{3}O_{12}$). The relative density and the mechanical properties of composites were increased with increasing $Al_{2}O_{3}+Y_{2}O_3$ contents because YAG of reaction between $Al_{2}O_3$ and $Y_{2}O_3$ was increased. The Flexural strength showed the highest value of 432.5MPa for composites added with l2wt% $Al_{2}O_{3}+Y_{2}O_3$ additives at room temperature. Owing to crack deflection, crack bridging, phase transition and YAG of fracture toughness mechanism. the fracture toughness showed 7.1MPa${\cdot}m^{1/2}$. For composites added with l2wt% $Al_{2}O_{3}+Y_{2}O_3$ additives at room temperature The electrical resistivity and the resistance temperature coefficient respectively showed the lowest of 6.0${\sim}10^{-4}{\Omega}{\cdot}$ cm and 3.1${\times}10^{-3}/^{\circ}C$ for composite added with l2wt% $Al_{2}O_{3}+Y_{2}O_3$ additives at room temperature. The electrical resistivity of the composites was all positive temperature coefficient resistance(PTCR) in the temperature range of 25$^{\circ}C$ to 700$^{\circ}C$.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.319-327
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• 2011

This study investigated whether the addition of porcine sperm cytosolic factor (SCF) at fusion/activation affects in vitro development of porcine parthenogenetic(PA) and nuclear transfer (NT) embryos. To determine the optimum concentration of SCF, control group of oocytes was activated with 0.3M mannitol (1.0 mM $CaCl_2{\cdot}2H_2O$), other three groups of oocytes were parthenogentically activated with the fusion medium (0.1mM $CaCl_2{\cdot}2H_2O$) supplemented with 100, 200 or 300 ${\mu}$g/ml SCF, respectively. Matured oocytes were activated with two electric pulses (DC) of 1.2 kv/cm for 30 ${\mu}$sec. The activated embryos were cultured in PZM-3 under 5% $CO_2$ in air at $38.5^{\circ}C$ for 6 days. Oocytes activated in the presence of SCF showed a significantly higher blastocyst rate than control (p<0.05). Apoptosis rate was significantly lower in 100 ${\mu}$g/ml SCF group than other groups (p<0.05). Cdc2 kinase activity in control and SCF treatment group of oocytes was determined using MESACUP cdc2 kinase assay kit at 1, 5, 10, 15, 30, 45 and 60 min after activation. Cdc2 kinase activity was significantly decreased (p<0.05) in SCF group than MII oocytes or control within 5 min. For NT embryo production, reconstructed oocytes were fused in the fusion medium supplemented with 0.1 mM $CaCl_2{\cdot}2H_2O$ (T1), 1.0 mM $CaCl_2{\cdot}2H_2O$ (T2) and 0.1 mM $CaCl_2{\cdot}2H_2O$ with 100 ${\mu}$g/ml SCF (T3). Fused embryos were cultured in PZM-3 under 5% $CO_2$ in air at $38.5^{\circ}C$ for 6 days. Developmental rate to blastocyst stage was significantly higher in T3 than other groups (23.0% vs. 13.5 to 15.2%) (p<0.05). Apoptosis rate was significantly lower in T3 than T1 or T2 (p<0.05). The relative abundance of Bax-${\alpha}$/Bcl-xl was significantly lower in in vivo or SCF group than that of control (p<0.05). Moreover, the expression of p53 and caspase3 mRNA was significantly lower in in vivo or SCF group than that of control (p<0.05). These results indicate that the addition of SCF at fusion/activation might improve in vitro development of porcine NT embryos through regulating cdc2 kinase level and expression of apoptosis related genes.

• Korean Journal of Crystallography
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• v.10 no.1
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• pp.33-38
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• 1999

The complex [Ni(L2)(H2O)]Cl·H2O (1) (L2=3,14-dimethyl-2,6,13,17-tetraazartricyclo [14,4,01.18,07.12]docosane-N-acetic acid) has been synthesized and characterized by X-ray crystallography. 1 crystallizes in the triclinic system, space group P, with a=11.274(1), b=13.851(1), c=17.159(6) , α=90.24(2), β=101.10(2), γ=92.11(1)o V=2682.5(11) 3, Z=4, R1=0.042 and wR2=0.111 for 9432 observed reflections with [I>2σ(I)]. The central nicke(II) ion is six-coordinated octahedral geometry with bonds to the four amine nitrogen atoms the carboxylic oxygen atom of the macrocyclic ligand and to the water molecule occupying a position trans to the pendant arm.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.177-185
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• 2015

The aim of this study was to investigate the amounts of glucosinolates (GSL) in kale at various development stages. Kale varieties 'Manchoo Collard' and 'TBC' were cultivated from 20 February 2012 to 3 July 2013 in the greenhouse at Chungnam National University. During the cultivation periods, samples were harvested at 35, 63, 91, 105, 119, and 133 days after sowing (DAS) and the amount of GSL quantified by HPLC. Ten types of GSL (progoitrin, sinigrin, glucoalyssin, gluconapin, glucoiberverin, 4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin) were observed in 'TBC', whereas nine types of GSL (the same as above, except glucoiberverin) were identified in 'Manchoo Collard'. The amount of total GSL in 'Manchoo Collard' was comparatively higher at 133 DAS (mean $8.64{\mu}mol{\cdot}g^{-1}$) and lower at 35 DAS ($1.16{\mu}mol{\cdot}g^{-1}$ dry weight, DW) of cultivation. In the case of 'TBC', the amount of GSL was higher at 91 DAS (mean $13.41{\mu}mol{\cdot}g^{-1}$) and lower at 35 DAS ($0.31{\mu}mol{\cdot}g^{-1}$ dry weight, DW). Sinigrin was the most abundant GSL (57% of total GSL) in 'Manchoo Collard' at 133 DAS and was also highest (44%) in 'TBC' at 91 DAS. Together, progoitrin, sinigrin, glucobrassicin, and gluconasturtiin, the precursor of crambene, allylisothiocyanate, indol-3-cabinol, and phenethylisothiocyanate accounted for 94 and 78% of GSL in 'Manchoo Collard' and 'TBC', respectively. Our results demonstrate that the amounts of GSL, which have potential anti-carcinogenic activity, change during development in kale.