• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
• /
• pp.45-48
• /
• 1997

Enhancing the electrical conductivity of the ultrathin organic films is one of the important factors for the development of molecular electronic devices. The Langmuir-Blodgett(LB) technique has recently been attracted interest as the a method of deposition ultrathin films. We have fabricated N-docosyl-N'-methyl viologen-diTCNQ(DMVT) anion radical LB film and investigated the optical and electrical conductivity. We have measured UV/visible and FT-lR spectrum. In ESR spectrum, we confirmed that a half-amplitude linewidth is clearly dependent on both temperature and incident angle, which indicates conducting species change. The in-plane electrical conductivity of 21 layers is approximately 1.37$\times$10$^{-6}$ (S/cm).

• 미생물학회지
• /
• 제30권6호
• /
• pp.553-557
• /
• 1992

변형된 Pfennig 배지에서 Glutamate 를 질소원으로 배앙한 다음 수확된 Chlorobium limicola f. thiosulfatophilum NCIB 8327 의 세포에서 수소생산이 수소 전극법 (hydrogen electrode)으로 측정되었다. 이 방법에 의해서 수소발생을 측정할 때, 산소, 빛, 암모니아 NADPH, ATP, methionine sulfoximine, NADPH, ATP, methionine sulfoximine, NADPH, ATP, methl viologen, 및 methionine sulfoximine 의 농도에 따라 변하는 것을 보았을 때 본 균주에서의 수소생산은 nitrogenase 에 의존하고 있음을 알 수 있었다.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제7권2호
• /
• pp.112-116
• /
• 2002

Effects of artificial electron donors to deliver reducing power on enzymic denitrification were investigated using nitrate reductase and nitrite reductase obtained from Ochrobactrum antroyi. The activity of nitrite reductase in the soluble portion was almost the same as that in the precipitated portion of the cell extract. Nitrate removal efficiency was higher with benzyl viologen than with methyl viologen or NADH as an artificial electron donor. The turn-over numbers of nitrate and nitrite reductase were 14.1 and 1.9 umol of nitrogen reduced/min$.$mg cell extracts, respectively when benzyl viologen was used as an electron donor.

• Journal of Plant Biotechnology
• /
• 제4권4호
• /
• pp.171-178
• /
• 2002

Chlorophyll (Chl) fluorescence imaging was used to investigate the effectiveness of in vivo incorporation methods for two chemicals, 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (DCMU) and methyl viologen (MV) in rice, a monocot, and cucumber, a dicot, leaves. four different methods (vacuum infiltration, floating, transpiration-aided incorporation through petiole and spraying) were compared, and $F_i$ and $F_v$/$F_m$ were chosen for the imaging of the DCMU- and MV-treated leaves, respectively. The effects of the chemicals in plants were generally heterogeneous over the whole leaf area. Moreover, the effectiveness of the treatment of a chemical in plant leaves was dependent on chemical species, plant species, concentration of the chemical, the treatment method, the duration of the treatment, the existence of light and detergent, etc. In conclusion, we suggest that to achieve the proposed effects of chemicals in plants for an actual experiment, these factors must be considered before the chemical treatment, and the best method for the treatment of the chemicals tested was floating and vacuum infiltration in the dicot and the monocot leaves, respectively, as drawn from Chl fluorescence imaging analysis.

• Korean Chemical Engineering Research
• /
• 제57권6호
• /
• pp.868-873
• /
• 2019

본 연구에서는 유기물인 메틸 바이올로겐(methyl viologen, MV)과 템폴(4-hydroxy-TEMPO, TEMPOL)을 활물질로 사용하고 NaCl의 중성 전해질 기반 수계 유기 레독스 흐름전지 성능이 멤브레인에 따라 어떻게 영향을 받는지 분석하였다. 메틸 바이올로겐(MV)과 템폴(TEMPOL)은 중성 전해질인 염화나트륨(NaCl) 전해질에 대해 높은 셀전압(1.37 V)을 얻을 수 있다. 성능 비교를 위해 사용한 멤브레인은 두 가지이다. 첫째로, 상용 양이온 교환막 중 하나인 Nafion 117를 사용하였을 때 성능은 첫번째 사이클에서 충전만 일어났을 뿐 그 후 높은 저항 때문에 완전지가 작동하지 않았다. 하지만 두번째로 사용한 Fumasep 음이온 교환막(FAA-3-50)은 Nafion 117 멤브레인을 사용했을 때와는 다르게 비교적 안정적인 충방전 사이클링을 보였다. 전류 밀도 $40mA{\cdot}cm^{-2}$, 컷-오프 전압 0.55~1.7 V에서 전류 효율(charge efficiency)은 97%, 전압 효율(voltage efficiency)은 78%로 높게 나타났다. 방전 용량(discharge capacity)은 10사이클에서 $1.44Ah{\cdot}L^{-1}$로 이론 용량($2.68Ah{\cdot}L^{-1}$)의 54%를 나타내었다. 방전 용량의 용량 손실율(capacity loss rate)은 $0.0015Ah{\cdot}L^{-1}/cycle$ 로 나타났다. 순환주사전류 실험을 통해 Nafion 117 멤브레인과 Fumasep 음이온 교환막 사이의 이러한 성능차이는 활물질의 크로스 오버(cross over) 현상으로 인한 방전 용량 손실이 아닌 멤브레인과 활물질의 화학적 반응으로 인한 저항 증가가 원인임을 파악할 수 있었다.

• Journal of Plant Biotechnology
• /
• 제34권4호
• /
• pp.299-305
• /
• 2007

산화스트레스 유도성 SWPA2 프로모터 조절하에 항산화 효소 SOD와 APX 유전자를 동시에 엽록체에 발현시킨 형질전환 감자 (품종 수미)를 대상으로 methyl viologen (MV) 처리에 의해 유도되는 산화스트레스 내성을 잎절편체, 소식물체 및 식물체 수준에서 조사하였다. 잎 절편에 $3{\mu}M$ MV를 처리하였을 때 SSA 식물체의 잎절편체는 비형질전환 (NT) 식물체에 비해 40% 정도 상해를 적게 받았다. 소식물체 수준에서 MV에 의한 산화스트레스 내성을 조사하기 위하여 SSA감자 shoot을 $0.3{\mu}M$ MV 첨가 배지에 배양하였을 때 뿌리의 생장에서 내성이 나타났다. 또한 온실에서 4주 생장한 식물체에 $350{\mu}M$ MV를 처리하였을 경우에도 SSA 식물체는 NT 식물체에 비해 약 75% 손상을 적게 입은 것으로 나타내었다. 추후 SSA 식물체를 이용하여 건조, 고온 등의 복합재해에 내성을 분석이 진행되어야 할 것이며 그 결과 복합스트레스 내성 감자 품종 (수미)을 개발할 수 있을 것으로 기대한다.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
• /
• pp.284.3-285
• /
• 2002

Paraquat(methyl viologen) is a bis-quaternary ammonium compound as a wide range herbicide. which was first introduced as an oxidation-reduction indicator dye. When paraquat(fatal dose. 1-2g) was administered to men, the oxido-reduction system of cell was repeatedly acted to perpetuate the cell membrane system, Many death cases had been occurred after ingestion of paraquat around Daejon area for the last six months. (omitted)

• Molecules and Cells
• /
• 제27권1호
• /
• pp.67-74
• /
• 2009

Autophagy degrades toxic materials and old organelles, and recycles nutrients in eukaryotic cells. Whereas the studies on autophagy have been reported in other eukaryotic cells, its functioning in plants has not been well elucidated. We analyzed the roles of OsATG10 genes, which are autophagy-related. Two rice ATG10 genes - OsATG10a and OsATG10b - share significant sequence homology (about 75%), and were ubiquitously expressed in all organs examined here. GUS assay indicated that OsATG10b was highly expressed in the mesophyll cells and vascular tissue of younger leaves, but its level of expression decreased in older leaves. We identified T-DNA insertional mutants in that gene. Those osatg10b mutants were sensitive to treatments with high salt and methyl viologen (MV). Monodansylcadaverine-staining experiments showed that the number of autophagosomes was significantly decreased in the mutants compared with the WT. Furthermore, the amount of oxidized proteins increased in MV-treated mutant seedlings. These results demonstrate that OsATG10b plays an important role in the survival of rice cells against oxidative stresses.

• Journal of Plant Biotechnology
• /
• 제31권3호
• /
• pp.191-195
• /
• 2004

복합스트레스 내성 유전자 NDP kinase 2 유전자를 도입시킨 형질전환 감자를 개발하기 위하여 이 유전자를 산화스트레스에 의해 발현이 강하게 유도되는 SWPA2 프로모터 또는 enhanced CaMV 35S 프로모터에 연결한 벡터를 제작한 후 각각 Agrobacterium 매개로 형질전환 하였다. 기관발생 경로에 의해 kanamycin 저항성 식물체를 재분화 시킨 후 Southern 분석으로 외래 유전자가 안정적으로 감자 게놈내로 삽입되었음을 확인하였다. 형질전환 감자 식물체의 잎 조직을 대상으로 10 $\mu$M methyl viologen에 대한 내성 검정을 조사하여 산화스트레스 내성 형질전환 감자 식물체를 2 개체씩 선발하였다. 선발된 식물체는 건조, 고온 등의 여러 가지 환경스트레스 내성 분석을 실시할 예정이며 이로부터 복합재해에 내성을 지닌 감자 품종을 개발할 수 있을 것으로 기대한다.

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 2000년도 추계 학술대회
• /
• pp.181-188
• /
• 2000

The electrocatalytic reduction of NAD$^{＋}$ using diaphorase was studied. methyl viologen (MV$^{2＋}$) mediator between an electrode and the enzyme. Steady-state currents could be obtained under the conditions of slow scan rate, low MV$^{2＋}$concentration, and high NAD$^{＋}$ concentration as the electrode reaction was converted to an electrochemical-catalytic (EC') reaction. The biomecular rate constant for the reaction of the reduced methyl viologen with the oxidized diaphorase was estimated as 7.5$\times$10$^3$M$^{-1}$ s$^{-1}$ from the slope of the current versus [MV$^{2＋}$] plot. And the optimal concentrations of diaphorase, MV$^{2＋}$ and NAD$^{＋}$ in the mediated electrocatalytic reduction of NAD$^{＋}$ were decided by applying the cyclic voltammetry. The optimal concentrations of the species were obtained by finding the conditions which gave the highest and steady-state current at a gold-amalgam electrode. The highest and steady-state catalytic current was achieved under the conditions of 1.5 U/ml diaphorase, 0.2 mM MV$^{2＋}$, and 4.8 mM NAD$^{＋}$ at the scan rate of 2 mV s$^{-1}$ , suggesting that the rate of the electrocatalytic reation is the higest under the former conditions. The electrochemical procedure under the conditions of 1.5 U/ml diaphorase,0.2 mM MV$^{2＋}$, and 4.8 mM NAD$^{＋}$ was used favorably to drive an enzymatic reduction of pyruvate to D-lactate.