• Title/Summary/Keyword: Elevated $CO_2$

검색결과 489건 처리시간 0.037초

Transgenic Tobacco Plants Expressing a Mutant VU-4 Calmodulin Have Altered Nicotinamide Co-Enzyme Levels and Hydrogen Peroxide Levels

  • Oh, Suk-Heung;Park, Yoon-Sick;Yang, Moon-Sik
    • BMB Reports
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    • 제32권1호
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    • pp.1-5
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    • 1999

  • In order to understand the biological role of calmodulin in plants, transgenic tobacco plants expressing a calmodulin mutant (VU-4 calmodulin, lys to ile-115) gene have been analyzed. SDS-PAGE and Western-blot analyses showed that the foreign calmodulin mutant is stably and highly expressed in the transgenic tobacco plants. The levels of $H_2O_2$were elevated approximately 2-fold in the transgenic plants. Furthermore, the transgenic tobacco plants have more than 6-fold higher levels of NADPH compared to control tobacco plants. The present findings, combined with previous data showing differences in the susceptibility of the transgenic tobacco seeds and normal tobacco seeds to fungal contamination (Oh and Yang, 1996), suggest that the expression of the calmodulin derivative gene in tobacco plants could increase resistance to infection by fungal pathogens.

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Reduction of Alkyl Halides by Homonuclear Bridging Hydride, (μ-H)[(η$^5-MeCp)$Mn(CO)₂]₂-ppn+

  • 박용광;김영웅
    • Bulletin of the Korean Chemical Society
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    • 제17권3호
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    • pp.269-273
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    • 1996

  • Alkyl halides were reduced to the corresponding alkanes by the homonuclear bridging hydride, (μ-H)[(η5-MeCp)Mn(CO)2]2-PPN+ in THF at the elevated temperatures (40-60 ℃) under the pseudo first order reaction conditions where excess of alkyl halide was employed under nitrogen atmosphere. The reaction is of overall second order; first order with respect to [bridging hydride] and first order with respect to [alkyl halide] with the activation parameters, ΔH≠=28.93 kcal/mol and ΔS≠=17.95 e.u. The kinetic data, the ESR evidence and the reaction with cyclopropyl canbinyl bromide ensure that two possible reaction pathways are operable in this reaction: (1) concerted mechanism, and (2) single electron transfer pathway are in competition leading to the same product, the corresponding alkane.

  • https://doi.org/10.5012/bkcs.1996.17.3.269 인용 PDF

제주도 고산에서의 미량기체 농도변화와 공기괴 특성과의 관계 (Variations of Trace Gases Concentrations and Their Relationship with the Air Mass Characteristic at Gosan, Korea)

  • 김인애;리선란;김경렬
    • 한국대기환경학회지
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    • 제24권5호
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    • pp.584-593
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    • 2008

  • The surface $O_3,\;CO,\;NO_x,\;and\;SO_2$ were measured at Gosan in Jeju Island from May 2004 to April 2005. Over this period, the mean concentrations $({\pm}s.d.)$ of each gas was 40.06 $({\pm}16.01)$ ppbv for $O_3,\;264.92({\pm}115.73)ppbv\;for\;CO,\;1.98({\pm}2.73)ppbv\;for\;SO)_2,\;and\;4.64 ({\pm}3.24) ppbv\;for\;NO_x$. The monthly variations and the diurnal variations of these gases show that the Gosan site is situated in a relatively clean region. However, there were episodic simultaneous peaks in CO and $SO_2$, especially in winter and early spring. Using cluster analysis with air mass back- ward trajectory analysis, we suggest that these episodes are due to the influence of transportation of polluted air mass from polluted regions. In the cluster, which was under the dominant influence of clean maritime air mass, low levels of $O_3,\;CO,\;and\;SO_2$ were observed. The levels of these species were elevated in the other two clusters which had the air mass influenced by polluted continental regions. In addition, ratios of the chemical species such as $CO/NO_x,\;SO_2/NO_x,\;and\;CO/SO_2$ revealed the somewhat different characteristics of emission sources influencing each cluster. The differences in concentration of trace gases among clusters with different origin and transport pathways imply that Gosan is under the effect of pollution transported from other regions.

  • https://doi.org/10.5572/KOSAE.2008.24.5.584 인용 PDF KSCI

Se-loss-induced CIS Thin Films in RTA Process after Co-sputtering Using CuSe2 and InSe2 Targets

  • Kim, Nam-Hoon;Jun, Young-Kil;Cho, Geum-Bae
    • Journal of Electrical Engineering and Technology
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    • 제9권3호
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    • pp.1009-1015
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    • 2014

  • Chalcopyrite $CuInSe_2$ (CIS) thin films were prepared without Se- / S-containing gas by co-sputtering using $CuSe_2$ and $InSe_2$ selenide-targets and rapid thermal annealing. The grain size increased to a maximum of 54.68 nm with a predominant (112) plane. The tetragonal distortion parameter ${\eta}$ decreased and the inter-planar spacing $d_{(112)}$ increased in the RTA-treated CIS thin films annealed at a $400^{\circ}C$, which indicates better crystal quality. The increased carrier concentration of RTA-treated p-type CIS thin films led to a decrease in resistivity due to an increase in Cu composition at annealing temperatures ${\geq}350^{\circ}C$. The optical band gap energy ($E_g$) of CIS thin films decreased to 1.127 eV in RTA-treated CIS thin films annealed at $400^{\circ}C$ due to the improved crystallinity, elevated carrier concentration and decreased In composition.

  • https://doi.org/10.5370/JEET.2014.9.3.1009 인용 PDF KSCI KPUBS HTML