• 전기의세계
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• 제46권5호
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• pp.19-27
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• 1997

본 논문은 제 2장에서 실시간 시스템의 기본 특성에 대해 보다 자세하게 살펴본 후, 제 3장에서 플랜트의 동적 특성을 관련 제어이론을 활용하여 실시간 시스템의 가장 중요한 정보인 작업 데드라인을 유도하는 방법을 살펴본다. 제 4장에서는 효율적인 실시간 제어 컴퓨터를 설계 및 평가하기 위해 실시간 시스템 분야에서 수행되는 연구동향으로 다음과 같은 세부 분야를, i) 스케줄링, ii)실시간 컴퓨터 언어, iii)실시간 운영체계(O/S), iv)실시간 동기화, v) 실시간 H/W 구조(architecture), vi) 실시간 통신, vii) 고장허용기법(fault-tolerance)에 대해 설명하고, 마지막 장에서 향후의 관련 연구 과제들에 대해 간단한 소개로 결론짓는다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.235-235
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• 2017

Chromium (Cr) toxicity is hazardous to the seed germination, growth, and development of plants. ${\gamma}$-Aminobutyric acid (GABA) is a non-protein amino acid and is involved in stress tolerance in plants. To investigate the effects of GABA in alleviating Cr toxicity, we treated eight-d-old mustard (Brassica juncea L.) seedlings with Cr (0.15 mM and 0.3 mM $K_2CrO_4$, 5 days) alone and in combination with GABA ($125{\mu}M$) in a semi-hydroponic medium. The roots and shoots of the seedlings accumulated Cr in a dose-dependent manner, which led to an increase in oxidative damage [lipid peroxidation; hydrogen peroxide ($H_2O_2$) content; superoxide ($O{_2}^{{\cdot}-}$) generation; lipoxygenase (LOX) activity], MG content, and disrupted antioxidant defense and glyoxalase systems. Chromium stress also reduced growth, leaf relative water content (RWC), and chlorophyll (chl) content but increased phytochelatin (PC) and proline (Pro) content. Furthermore, supplementing the Cr-treated seedlings with GABA reduced Cr uptake and upregulated the non-enzymatic antioxidants (ascorbate, AsA; glutathione, GSH) and the activities of the enzymatic antioxidants including ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II), and finally reduced oxidative damage. Adding GABA also increased leaf RWC and chl content, decreased Pro and PC content, and restored plant growth. These findings shed light on the effect of GABA in improving the physiological mechanisms of mustard seedlings in response to Cr stress.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.189-189
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• 2022

Soil salinity negatively affects plant growth, productivity, and metabolism. Rice is known to have more sensitive phenotypes than other cereal crops, such as wheat, sorghum, and barley. We characterized the molecular function of rice C3HC4 as a really interesting new gene (RING). Oryza sativa RING finger protein H2-3 (OsRFPH2-3) was highly expressed in 100 mM NaCl. To identify the localization of OsRFPH2-3, we fused vectors that include C-terminal GFP protein (35S;;OsRFPH2-3-GFP). OsRFPH2-3 was expressed in the nucleus in rice protoplasts. An in vitro ubiquitin assay demonstrated that OsRFPH2-3 possessed E3-ubiquitin ligase activity. However, the mutated OsRFPH2-3 were not possessed any E3-ubiquitin ligase activity. Under normal conditions, there is no significant phenotypic difference between transgenic plants and WT plants. However, OsRFPH2-3-overexpressing plants exhibited higher fresh weight and length under saline conditions. Also, transgenic plants maintain higher chlorophyll, proline, and soluble sugar contents and lower H₂O₂ and MDA contents than the wild type; these results support transgenic plants with enhanced salinity tolerance phenotypes.

• 한국초지조사료학회지
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• 제39권1호
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• pp.39-44
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• 2019

Drought is one of the key limiting factors that adversely affects the growth and productivity of crop plants. For the enhancement of drought tolerance in crop plants, the identification of basic mechanisms of a plant to drought stress is necessary. In this study, we compared physiological and biochemical responses of five local Arundenilla hirta ecotypes to drought stress. These ecotypes were previously collected from various parts of Korean peninsula, including Youngduk, Gunsan, Jangsoo, Jinju-1 and Yecheon. A. hirta plants were exposed to drought stress for 14 and 17 days respectively, followed by re-watering for 3 days. The results showed that the lipid peroxidation (MDA), hydrogen peroxide ($H_2O_2$), DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, and proline level were significantly increased while the chlorophyll content was decreased by drought stress in A. hirta leaves. The highest proline content and DPPH scavenging activity were shown in Ecotype of Youngduk with least MDA and $H_2O_2$ levels while the highest MDA and $H_2O_2$ contents, and least proline and DPPH levels were shown in Gunsan, respectvely. These results indicate that the Youngduk is the most tolerant and Gunsan is the most sensitive ecotype among the five different collections. Together, these results provide a new insight of overall physiological responses of A. hirta to drought stress.

• Natural Product Sciences
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• 제25권3호
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• pp.255-260
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• 2019

Piper nigrum L. (Piperaceae), which is a well-known food seasoning, has been used as a traditional medicine for the treatment of vomiting, abdominal pain, diarrhea and anorexia in Korea, China and Japan. Methanol extract from the fruit of P. nigrum was successively partitioned as n-hexane, methylene chloride, ethyl acetate, n-butanol and $H_2O$ soluble fractions. Among those fractions the ethyl acetate soluble fraction showed the most potent DPPH radical scavenging activity, and piperine was isolated from the ethyl acetate fraction. To know the antioxidant activity of piperine, we tested the activities of superoxide dismutase (SOD) and catalase together with oxidative stress tolerance and intracellular ROS level in Caenorhabditis elegans. To investigate whether piperine-mediated increased stress tolerance was due to regulation of stress-response gene, we quantified SOD-3 expression using transgenic strain including CF1553. Consequently, piperine enhanced SOD and catalase activities of C. elegans, and reduced intracellular ROS accumulation in a dose-dependent manner. Moreover, piperine-treated CF1553 worms exhibited significantly higher SOD-3::GFP intensity.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.9-18
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• 2012

This study was carried out to leach valuable metal ions from the mine waste ore using the adapted indigenous bacteria. In order to tolerance the heavy metals, the indigenous bacteria were repeatedly subcultured in the adaptation-medium containing $CuSO_4{\cdot}5H_2O$ for 3 weeks and 6 weeks, respectively. As the adaptation experiment processed, the pH was rapidly decrease in the adaptation-medium of 6 weeks more than the 3 weeks. The result of bioleaching with the adapted bacteria for 42 days, the pH value of leaching-medium in the 3 weeks tend to increased, whereas the pH of the 6 weeks decreased. In decreasing the pH value in the adaptation-medium and in the leaching-medium, it was identified that the indigenous bacteria were adapted $Cu^{2+}$ the ion and the mine waste ores. The contents of Cu, Fe and Zn in the leaching solution were usually higher leached in 6 weeks than 3 weeks due to the adaptation. Considering the bioleaching rates of Cu, Fe and Zn from these leaching solutions, the highest increasing the efficiency metal ion were found to be Fe. Accordingly, it is expected that the more valuable element ions can be leached out from the any mine waste, if the adapted bacteria with heavy metals will apply in future bioleaching experiments.

• 한국산림과학회지
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• 제90권1호
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• pp.83-89
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• 2001

본 연구는 외생균근균 중 중금속에 대한 내성이 우수한 것으로 알려져 있는 모래밭버섯균의 Cd 축적과 내성 특성을 밝히고자 수행하였다. 모래밭버섯균은 1997년 전남 무안의 곰솔림에서 분리한 것으로 MMN 배지에 $CdSO_4{\cdot}5H_2O$을 0, 0.2, 0.5, 2, $10{\mu}g/m{\ell}$로 첨가하여 기내에서 배양하였다. 배양을 시작한 후 일주일 간격으로 24일 동안 생장량과 내성지수를 측정하였으며, 40일 후에는 균사를 수확하여 Cd 함량, superoxide dismutase(SOD) 활성, glutathione reductase(GR) 활성을 측정 하였다. 기내 배양된 모래밭버섯균은 Cd $2{\mu}g/m{\ell}$ 처리에서 생장이 감소하였으며, Cd $10{\mu}g/m{\ell}$의 처리에서는 생장이 거의 정지하였다. 대조구와 Cd 처리구의 생장량 비로 결정된 모래밭버섯균의 내성지수는 Cd 처리 농도가 증가함에 따라 점차 감소하는 경향을 나타냈으나 Cd $0.5{\mu}g/m{\ell}$와 Cd $2{\mu}g/m{\ell}$ 처리구에서는 14일 경과 후 다시 증가하였다. 모래밭버섯균의 균사내 Cd 농도는 Cd 처리 농도 증가에 따라 증가하였으며, 특히 Cd $10{\mu}g/m{\ell}$ 처리의 균사내 Cd 농도는 $854{\mu}g/g$으로, Cd $0.5{\mu}g/m{\ell}$ 처리구의 균사내 농도 $12.3{\mu}g/g$보다 70배 높았다. 모래밭버섯균의 SOD 활성은 Cd 농도별 처리간에 큰 차이를 보이지 않았다. 그러나 GR 활성은 Cd $0.5{\mu}g/m{\ell}$ 처리구에서 대조구보다 높았으며 Cd $2{\mu}g/m{\ell}$에서는 대조구보다 낮았다. 결론적으로 모래밭버섯균은 Cd의 흡수가 뛰어나며, Cd에 대한 내성은 비교적 저농도에서 항산화효소의 합성 증가와 같은 독성 제거 기작을 통하여 나타난다고 판단된다. 따라서 모래밭버섯균은 저농도로 오염된 중금속 오염지의 식생 복원에 이용이 가능하다고 본다.

• 한국산림과학회지
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• 제106권1호
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• pp.33-39
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• 2017

본 연구는 내음성이 있는 수종으로 알려진 난대 상록활엽수인 굴거리나무 용기묘를 대상으로, 피음 수준에 따른 생장과 생리적 반응을 알아보고자 실시되었다. 피음은 전광과 전광의 35%, 55%, 75% 수준으로 조절하여 처리하였다. 피음 수준에 따른 1년생 용기묘의 간장과 근원경 생장 조사 결과, 간장은 35% 피음에서 13.2 cm로 가장 컸으며, 근원경은 전광에서 4.99 mm로 가장 굵었다. 잎, 줄기, 뿌리 및 전체 건물생산량은 모두 35% 피음에서 각각 1.38 g, 0.47 g, 0.87 g, 2.72 g으로 높았다. 엽록소 a, b 및 총 엽록소 함량은 상대적으로 피음 수준이 가장 높은 75% 피음에서 가장 높았으며, 엽록소 a/b율은 35% 피음에서 가장 높게 조사되었다. 광합성 속도, 기공전도도 및 수분이용효율은 35% 피음에서 각각 $12.3{\mu}molCO_2{\cdot}m^{-2}{\cdot}s^{-1}$, $0.27molH_2O{\cdot}m^{-2}{\cdot}s^{-1}$, $3.53{\mu}molCO_2{\cdot}mmol^{-1}H_2O$로 가장 높았다. 이러한 결과를 종합하면, 내음성이 있는 굴거리나무는 35% 피음 수준이 생육에 적정한 것으로 판단된다.

• 한국수소및신에너지학회논문집
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• 제23권4호
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• pp.346-352
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• 2012

The properties of methane oxidation were studied in this research over transition metal containing $CeO_2$ (TM/$CeO_2$, TM=Ni, Co, Cu, Fe) with TM content of 5 wt. % at atmospheric pressure. The characteristics of catalysts were investigated by various characterization techniques, including XRD, GC, SEM and EPMA analyses. The catalytic tests were carried out in a fixed Rmix ratio of 1.5 ($CH_4/O_2$) in a fixed-bed reactor operating isothermally at atmospheric pressure. Only the Ni/$CeO_2$ catalysts showed syngas production above $400^{\circ}C$ via typical partial oxidation reaction whereas other catalysts induced complete oxidation resulting in the production of $CO_2$ and $H_2O$ in whole reaction temperature range. From the quantitative analysis on carbon deposition after catalytic tests, Cu/$CeO_2$ was found to show the highest resistance on carbon deposition. Therefore Cu can be proposed as an efficient catalyst element which can be combined with a conventional Ni-based SOFC anode to enhance the carbon tolerance.

• Journal of Plant Biotechnology
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• 제44권3호
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• pp.287-295
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• 2017

Water temperature is one of the major factors that impacts the growth and life cycle of Pyropia tenera, one of the most valuable and cultivated marine red algae belonging to Bangiales (Rhodophytes). We analyzed transcriptome from gametophyte of P. tenera under normal and high temperature conditions, and identified four small heat shock proteins (sHSPs). They have no significant amino acid sequence homology with known proteins in public databases except PhsHSP22 from Pyropia haitanensis. PtsHSP19.3 gene responded to high temperature but slightly or not to desiccation, freezing or high salt condition. When the PtsHSP19.3 gene was overexpressed in Chlamydomonas reinhardtii, transformed Chlamydomonas lines revealed much higher growth rate than that of control cells under heat stress condition. Transformed cells also grew well in those of the control cell onto the medium containing high salt or $H_2O_2$. When the PtsHSP19.3 was fused to GFP and introduced into tobacco protoplast, fluorescence was detected at several spots. Results indicate that PtsHSP19.3 may form super-molecular assembles and be involved in tolerance to heat stress.