• BMB Reports
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• 제44권3호
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• pp.165-169
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• 2011

Excess free iron generates oxidative stress that may contribute to the pathogenesis of various causes of neurodegenerative diseases. In this study, we assessed the modification of ferritin induced by $H_2O_2$. When ferritin was incubated with $H_2O_2$, the degradation of ferritin L-chain increased with the $H_2O_2$ concentration whereas ferritin H-chain was remained. Free radical scavengers, azide, thiourea, and N-acetyl-$_L$-cysteine suppressed the $H_2O_2$-mediated ferritin modification. The iron specific chelator, deferoxamine, effectively prevented $H_2O_2$-mediated ferritin degradation in modified ferritin. The release of iron ions from ferritin was increased in $H_2O_2$ concentration-dependent manner. The present results suggest that free radicals may play a role in the modification and iron releasing of ferritin by $H_2O_2$. It is assumed that oxidative damage of ferritin by $H_2O_2$ may induce the increase of iron content in cells and subsequently lead to the deleterious condition.

• BMB Reports
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• 제46권2호
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• pp.113-118
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• 2013

TTRAP is a multi-functional protein that is involved in multiple aspects of cellular functions including cell proliferation, apoptosis and the repair of DNA damage. Here, we demonstrated that the lentivirus-mediated overexpression of TTRAP significantly inhibited cell growth and induced apoptosis in osteosarcoma cells. The ectopic TTRAP suppressed the growth and colony formation capacity of two osteosarcoma cell lines, U2OS and Saos-2. Cell apoptosis was induced in U2OS cells and the cell cycle was arrested at G2/M phase in Saos-2 cells. Exogenous expression of TTRAP in serum-starved U2OS and Saos-2 cells induced an increase in caspase-3/-7 activity and a decrease in cyclin B1 expression. In comparison with wild-type TTRAP, mutations in the 5'-tyrosyl-DNA phosphodiesterase activity of TTRAP, in particular $TTRAP^{E152A}$, showed decreased inhibitory activity on cell growth. These results may aid in clarifying the physiological functions of TTRAP, especially its roles in the regulation of cell growth and tumorigenesis.

• Plant Resources
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• 제8권3호
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• pp.217-224
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• 2005

We tested the hypothesis that alpine plants have special physiological and biochemical mechanisms in addition to their structural adaptation in order to survive under extreme conditions. The photosynthetic organs of Pinus pumila were used to examine the seasonal changes in sugar concentration, antioxidative enzyme, and lipid peroxidation. The concentrations of sucrose, glucose, fructose and reducing sugar were the highest in the leaves in April. But sugar contents in buds and inner barks did not respond sensitively on temperature change. Meanwhile superoxide dismutase (SOD) activity responded sensitively on the change of temperature and SOD in all tissues maintained high activity in April. Meanwhile anthocyanin content increased rapidly in June but the increase of anthocyanin content was not enough to prevent their tissues from the damage by the exposure of high temperature or other stress. In conclusion, under low temperature condition, P. pumila increased the concentration of soluble sugars and SOD activity in their tissues in order to overcome extreme environmental condition. But in summer, these stress defense system against high temperature might be disturbed slightly. This results in the increase of malondialdehyde (MDA) contents in three tissues by lipid peroxidation.

• 한국작물학회지
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• 제52권2호
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• pp.140-145
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• 2007

본 연구는 효율적인 콩 노린재 검정방법을 개발하고 저항성 유전자원 선발하여 콩 노린재 저항성 품종개발을 위한 기초 자료를 마련하고자, 영남농업연구소에 보존되고 있는 콩 유전자원 298자원을 공시하여 $2001{\sim}2004$년에 걸쳐 수행하였다. 1. 1년차에 298개의 유전자원에 대하여 노린재 피해율을 조사하였더니, 40%정도의 피해율을 나타낸 품종이 가장 많았고, 10%이하로 피해율이 낮은 품종도 10개정도 선발되었다. 2. 전년도에 피해율이 비교적 낮은 102개의 유전자원을 대상으로 2년차 선발을 수행한 결과, 12품종에서 10%미만의 낮은 노린재 피해율을 나타내었으며, 기타 대부분은$20{\sim}30%$의 피해율이었다. 3. 아울러 효율적인 노린재검정방법을 개발하고자 일품검정콩을 공시하여 콩 생육단계별 노린재 피해정도를 조사한 결과, 협비대기보다 종실비대기에서 노린재 피해협율이 급격히 높아지는 경향을 보였으며, R6에서 35.5%로 노린재 피해가 가장 심하였다. 4. 협피해율에 따른 저항성 유전자원을 선발한 결과는 Peking이 10.3%로 가장 낮았고, 소록콩, 황색준저리 및 소백나물콩 순서로 낮았으며, 이러한 결과는 종실에서도 유사하였으며, 공통적으로 소립종이 대립종에 비하여 저항성 정도가 강한 경향을 나타내었다. 5. 또한 노린재 기피반응을 구체적으로 구명하기 위하여 Peking과 소록콩을 별도로 시험한 결과, R5시기에서는 Peking이 10.0% 및 소록콩이 14.2%의 피해율을 보였지만, R5.5시기를 넘어가면서 피해율이 급격히 저하되는 것으로 보아 이 시기에 콩 내부 조직적으로 노린재의 접근을 저지시키는 성분변화가 나타나는 것으로 추측되었다. 6. 상기의 결과로부터 소록콩, 소백나물콩, Peking 및 황색준저리 등 4개의 저항성 유전자원은 금후 노린재에 대한 내충성 콩 품종개발을 위한 육종소재로서의 이용이 기대된다.

• Journal of Forest and Environmental Science
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• 제25권3호
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• pp.147-155
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• 2009

Higher plants provide valuable genetic assay systems for screening and monitoring environmental pollutants. They are now recognized as excellent indicators of mutagenic effects of environmental chemicals and are applicable for the detection of environmental mutagens both indoor and outdoor. 2,4-dichlorophenoxyacetic acid (2,4-D) is a herbicide commonly used in agriculture. The residues of 2,4-D are present in air, water, soil and edible plants. It constitutes a real hazard to the public health because it's wide spread use in agriculture. Genotoxic effects of 2,4-D on plant cells and potential of higher plants as a biomonitoring system for detecting chemical mutagens are evaluated. It is recommended that higher plant systems have been accepted by regulatory authorities as an alternative biomonitoring system for the detection of possible genetic damage resulting from pollution and the use of environmental chemicals.

• Smart Structures and Systems
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• 제10권1호
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• pp.47-65
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• 2012

The presence of crack-like defects in mechanical and structural elements produces failures during their service life that in some cases can be catastrophic. So, the early detection of the fatigue cracks is particularly important because they grow rapidly, with a propagation velocity that increases exponentially, and may lead to long out-of-service periods, heavy damages of machines and severe economic consequences. In this work, a non-destructive method for the detection and identification of elliptical cracks in shafts based on stress wave propagation is proposed. The propagation of a stress wave in a cracked shaft has been numerically analyzed and numerical results have been used to detect and identify the crack through the genetic algorithm optimization method. The results obtained in this work allow the development of an on-line method for damage detection and identification for cracked shaft-like components using an easy and portable dynamic testing device.

• 한국산림과학회지
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• 제95권2호
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• pp.216-219
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• 2006

After long exposure to low-density $SO_2$ the five tree species showed different changes in their visible damage: Ailanthus altissima showed no visible damage; Acanthopanax sessiliflorus, Populus alba ${\times}$ Populus glandulosa, and Platanus orientalis showed typical damage of yellow spots on their leaves; and Liriodendron tulipifera showed serious damage on the end of leaf tip. The photosynthesis rate of Liriodendron tulipifera and Acanthopanax sessiliflorus was usually lower than the control group: Ailanthus altissima, Populus alba ${\times}$ Populus glandulosa, and Platanus orientalis showed no difference from the control group, while Acanthopanax sessiliflorus and Liriodendron tulipifera showed large changes. In regard to the light compensation points, Ailanthus altissima showed similar values, Populus alba ${\times}$ Populus glandulosa and Platanus orientalis exposed to $SO_2$, showed 3 to $5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ higher values than the control group, and Acanthopanax sessiliflorus and Liriodendron tulipifera exposed to $SO_2$ showed approximately twice higher light compensation points.

• Structural Engineering and Mechanics
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• 제70권3호
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• pp.339-350
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• 2019

This research focuses on finite element model updating and damage assessment of structures at element level based on global nondestructive test results. For this purpose, an optimization system is generated to minimize the structural dynamic parameters discrepancies between numerical and experimental models. Objective functions are selected based on the square of Euclidean norm error of vibration frequencies and modal assurance criterion of mode shapes. In order to update the finite element model and detect local damages within the structural members, modern optimization techniques is implemented according to the evolutionary algorithms to meet the global optimized solution. Using a simulated numerical example, application of genetic algorithm (GA), particle swarm (PSO) and artificial bee colony (ABC) algorithms are investigated in FE model updating and damage detection problems to consider their accuracy and convergence characteristics. Then, a hybrid multi stage optimization method is presented merging advantages of PSO and ABC methods in finding damage location and extent. The efficiency of the methods have been examined using two simulated numerical examples, a laboratory dynamic test and a high-rise building field ambient vibration test results. The implemented evolutionary updating methods show successful results in accuracy and speed considering the incomplete and noisy experimental measured data.

• 대한의생명과학회지
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• 제11권2호
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• pp.103-108
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• 2005

2-Deoxyribonolactone (dL) arises as a major DNA damage induced by a variety of agents, involving free radical attack and oxidation of C1'-deoxyribose in DNA. We investigated whether dL lesions can be repaired in mammalian cells and the mechanisms underlying the role of DNA polymerase $\beta$ in processing of dL lesions. Pol $\beta$ appeared to be trapped by dL residues, resulting in stable DNA-protein cross-links. However, repair DNA synthesis at site-specific dL sites occurred effectively in cell-free extracts, but predominantly accompanied by long-patch base excision repair (BER) pathway. Reconstitution of long-patch BER demonstrated that FEN1 was capable of removing the displaced flap DNA containing a 5'-dL residue. Cellular repair of dL lesions was largely dependent on the DNA polymerase activity of Pol $\beta$. Our observations reveal repair mechanisms of dL and define how mammalian cells prevent cytotoxic effects of oxidative DNA lesions that may threaten the genetic integrity of DNA.

• Weed & Turfgrass Science
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• 제6권2호
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• pp.136-150
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• 2017

잔디혹응애(Aceria zoysiae)는 잔디에 중요한 해충의 하나로 특히 한국잔디에 피해가 심하다. 본연구에서는 자생 채집 잔디 유전자원 보존원에서 잔디혹응애 저항성 잔디 개체의 선발을 위하여 잔디혹응애 피해를 조사하였다. 온실에서 295 계통의 자생지 채집 잔디를 대상으로 잔디혹응애 피해율을 조사한 결과, 잔디혹응애 피해는 잔디 종과 채집 계통별로 차이가 있었다. 잔디혹응애 피해가 가장 많은 잔디 초종은 들잔디와 중지였다. 들잔디가 97.6%의 개체들이 잔디혹응애 피해를 받았으며 중지와 갯잔디가 각각 87.7, 81.1%의 개체들이 잔디혹응애 피해를 받았다. 2개체의 왕잔디도 잔디혹응애 피해가 있었지만 일부 개체들은 온실과 야외에서 잔디혹응애 피해가 없었다. 야외에서 잔디혹응애 피해는 5월부터 발생하여 7월이후 급증하였다. 본 조사에서 잔디혹응애의 피해가 없는 잔디계통들은 향후 잔디혹응애 관리에 활용될 수 있을 것이다.