• Proceedings of the EASDL Conference
• /
• 2004.10a
• /
• pp.93-105
• /
• 2004

• Journal of the korean veterinary medical association
• /
• v.48 no.6
• /
• pp.364-366
• /
• 2012

• Food Industry And Nutrition
• /
• v.5 no.1
• /
• pp.30-36
• /
• 2000

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.26 no.5
• /
• pp.52-59
• /
• 1989

The reliability of the thin thermal oxide was investigated by using constant current stress method. Polysilicon gate MOS capacitors with oxide thickness range of 20-25nm were used in this experiment. Automatic measurement and statistical data analysis which were essential in reliability evaluation of VLSI process preformed by HP 9000 computer. Based on TDDB results, defect density, breakdown charge (Qbd) and lifetime of oxide film were evaluated. According to the polarity of the stress, some different characteristics were shown. Defect density was 62/$cm^2$ at negative gate injection. The value of Qbd was about 30C/$cm^2$ at positive gate injection, and about 21C/$cm^2$ at negative. The current density acceleration factor was 1.43$cm^2$/A for negative gate injection, and 1.25$cm^2$/A for positive gate injection.

• Journal of Sensor Science and Technology
• /
• v.12 no.5
• /
• pp.218-224
• /
• 2003

The devices of n-channel poly silicon thin film transistors(TFTs) hydrogenated by plasma, $H_2$ and $H_2$/plasma processes are fabricated. The carriers sensitivity characteristics are analyzed with voltage bias stress at the gate oxide. The parametric sensitivity characteristics caused by electrical stress conditions in hydrogenated devices are investigated by measuring the drain current, threshold voltage($V_{th}$), subthreshold slope(S) and maximum transconductance($G_m$) values. As a analyzed results, the degradation characteristics in hydrogenated n-channel polysilicon thin film transistors are mainly caused by the enhancement of dangling bonds at the poly-Si/$SiO_2$ interface and the poly-Si grain boundary due to dissolution of Si-H bonds. The generation of traps in gate oxide are mainly dued to hot electrons injection into the gate oxide from the channel region.

• Proceedings of the KSCN Conference
• /
• 2004.05a
• /
• pp.392.2-394
• /
• 2004

최근 우리나라는 노인인구가 급격히 증가되고 있고, 주요사망원인이 만성퇴행성 질환으로 이동하고 있다. 노화는 산화-환원의 균형이 깨져 산화 촉진쪽으로 반응이 진행되어 일어나며, 이러한 산화적 스트레스의 증가는 당뇨병이나 고혈압과 같은 만성질환의 유병율을 높이고, 또한 면역기능에도 영향을 미친다. 그러므로, 노화 억제 및 만성질환의 예방을 위한 항산화 영양소의 건강증진 효과에 대한 연구가 매우 중요하다. 따라서 본 연구는 우리나라 노인들의 항산화 영양상태를 평가하고, 만성질환 중 유병율이 높은 당뇨병, 고혈압에 따른 항산화 영양상태와의 관련성 및 노인들에게서 감소하는 것으로 알려진 면역기능과의 관련성을 조사하기 위해 3차에 걸친 연구를 수행하였다.(중략)

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.2
• /
• pp.348-354
• /
• 2009

It has analyzed that the device degradation by NBTI (Negative Bias Temperature Instability) stress induced the increase of gate-induced-drain-leakage(GIDL) current for p-MOSFETs. It is shown that the degradation magnitude, as well as its time, temperature, and field dependence, is govern by interface traps density at the silicon/oxide interface. from the relation between the variation of threshold voltage and subthreshold slope, it has been found that the dominant mechanism for device degradation is the interface state generation. From the GIDL measurement results, we confined that the EHP generation in interface state due to NBTI stress led to the increase of GIDL current. Therefore, one should take care of the increased GIDL current after NBTI stress in the ultra-thin gate oxide device. Also, the simultaneous consideration of reliability characteristics and dc device performance is highly necessary in the stress engineering of nanoscale CMOSFETs.

• Journal of Plant Biotechnology
• /
• v.38 no.1
• /
• pp.22-29
• /
• 2011

Although reactive oxygen species (ROS) are inevitable by-products of many redox reactions in eukaryotic cells, they play a crucial role as signaling molecules in many cellular processes for development and defense response to abiotic stresses. The biphasic ROS production which was peaked twice in a first transient phase and a second massive phase was occurred after treatment of abiotic stress such as oxidative stress, high salinity. This biphasic generation of ROS was followed by the biphasic production of stress hormone, ethylene. The mechanism of interactions between ROS and ethylene biosynthesis is studied in tobacco (Nicotiana tabaccum L.) plants under the abiotic stresses. The stress-induced ethylene production was significantly inhibited in RbohD-AS and RbohF-AS, in which antisense expression of NADPH oxidase genes was performed. The accumulation of ROS, which was determined by DAB and DCFH-DA staining, was significantly decreased after abiotic stresses in transgenic plants. The suppression of signaling with ethylene and ROS induced more tolerance in response to abiotic stress. The transgenic plants were more tolerant in MS medium supplemented with salinity stress in contrast with wild-type. Stress-induced cell damage determined by DNA fragmentation was decreased at phase II in those transgenic plants. Therefore, the first burst of ROS is more responsible for making a role as a signaling molecule during stress-induced response. These results suggested that ethylene and ROS act in a positive feedback cycle that results in mutual enhancement of ethylene and ROS production during stress-induced cell death.

• Journal of Life Science
• /
• v.27 no.12
• /
• pp.1415-1420
• /
• 2017

The metallothionein (MT) gene (IbMT3) was selected from an EST library of suspension-cultured sweet potato cells. The MT gene, which is one of abundant ESTs in the library, is involved in stress regulation of cells and tissues. A full-length IbMT3 cDNA was obtained and analysis of its nucleotide sequence revealed that IbMT3 encoded a type 3 MT protein, based on its structural characteristics. The function of type 3 MT in plants is not yet known. Northern blot analysis showed stronger expression of IbMT3 in suspension-cultured cells than in sweet potato plant leaves. Since cell culture is known to impose a state of oxidative stress on cells, sweet potato plants were subjected to oxidative stress to investigate the transcriptional regulation of IbMT3. When the herbicide methyl viologen (MV) was administered for 6, 12, and 24 hr, IbMT3 transcription rapidly increased at 6 hr and then decreased. A cold treatment at $15^{\circ}C$ for 24 and 48 hr resulted in a gradual increase in IbMT3 expression. These findings indicate that IbMT3 expression is regulated in response to environmental and oxidative stress. IbMT3 isoform is expected to have antioxidant effects in sweet potato plants and may play an important role in cellular adaptation to oxidative stress.

• Journal of Plant Biotechnology
• /
• v.34 no.4
• /
• pp.299-305
• /
• 2007

Oxidative stress is a major damaging factor for plants exposed to environmental stresses. Previously, we have generated transgenic potato (cv. Superior) plants expressing both CuZnSOD and APX genes in chloroplast under the control of an oxidative stress-inducible SWPA2 promoter (referred to as SSA plants) and selected the transgenic potato plant lines with tolerance against methyl viologen (MV)-mediated oxidative stress. When leaf discs of SSA plants were subjected to $3{\mu}M$ methyl viologen (MV), they showed approximately 40% less damage than non-transgenic (NT) plants. SSA plantlets were treated with $0.3{\mu}M$ MV stress, SSA plants also exhibited reduced damage in root growth. When 350 MV was sprayed onto the whole plants, SSA plants showed a significant reduction in visible damage, which was approximately 75% less damage than leaves of NT plants. These plants will be used for further analysis of tolerance to environmental stresses, such as high temperature and salt stress. These results suggest that transgenic potato (cv. Superior) plants would be a useful plant crop for commercial cultivation under unfavorable growth conditions.