• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.10
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• pp.1-8
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• 1999

In this paper, we have studies the transport mechanism and origin of SILC for the various thickness of wet oxide. Also, SILC characteristics of $N_2O$ annealed oxide was included in this study. We made the flash memory cell with $N_2O$ annealed oxide of 60Athick under $0.25{\mu}m$ design rule, and measured the characteristics of the cell. As a result, we have found that the origin of SILC is due to the trap formed inside of the oxide layer by electrical stress. And we reached the conclusion that the transport mechanism of SILC is ruled by the modified F-N tunneling if the electric field is lower than 8MV/cm or typical F-N tunneling if the electric field is higher than 8MV/cm. We could also confirm the fact that $N_2O$ annealed oxide of 60Athick have an improved resistance effect against SILC. In case that we apply $N_2O$ annealed oxide of 60Athick to the flash memory, we could confirm $10^6$ times endurance and more than 10 years drain disturb, and could get 8V programmable flash memory characteristics.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.335-342
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• 2005

The effects of ginsenosides Rg$_3$(R) , Rg$_3$(S) and Rg$_5$/Rk$_1$ (a mixture of Rg$_5$ and Rk$_1$ 1:1, w/w), which are components isolated from processed Panax ginseng C.A. Meyer (Araliaceae), on memory dysfunction were examined in mice using a passive avoidance test. The ginsenosides Rg3(R), Rg3(S) or Rg$_5$/Rk$_1$, when orally administered for 4 days, significantly ameliorated the memory impairment induced by the single oral administration of ethanol. The memory impairment induced by the intraperitoneal injection of scopolamine was also significantly recovered by ginsenosides Rg3(S) and Rg$_5$/Rk$_1$. Among the three ginsenosides tested in this study, Rg$_5$/Rk$_1$ enhanced the memory function of mice most effectively in both the ethanol­and scopolamine-induced amnesia models. Moreover, the latency period of the Rg$_5$/Rk$_1$­treated mice was 1.2 times longer than that of the control (no amnesia) group in both models, implying that Rg$_5$/Rk$_1$ may also exert beneficial effects in the normal brain. We also evaluated the effects of these ginsenosides on the excitotoxic and oxidative stress-induced neuronal cell damage in primary cultured rat cortical cells. The excitotoxicity induced by glutamate or N­methyl-D-aspartate (NMDA) was dramatically inhibited by the three ginsenosides. Rg$_3$(S) and Rg$_5$/Rk$_1$ exhibited a more potent inhibition of excitotoxicity than did Rg$_3$(R). In contrast, these ginsenosides were all ineffective against the H$_2$O$_2$- or xanthine/xanthine oxidase-induced oxidative neuronal damage. Taken together, these results indicate that ginsenosides Rg$_3$(S) and Rg$_5$/Rk$_1$ significantly reversed the memory dysfunction induced by ethanol or scopolamine, and their neuroprotective actions against excitotoxicity may be attributed to their memory enhancing effects.

• The Journal of Internal Korean Medicine
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• v.32 no.1
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• pp.100-112
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• 2011

Objectives : This study investigated the effects of electroacupuncture on memory, depression, and plasma stress hormone levels in rats that were under immobilization stress. Materials and Methods : The immobilization-only group was given two hours of immobilization stress for 10 consecutive days. The immobilization and high frequency EA group was given two hours of immobilization stress simultaneously with high frequency (100Hz) electroacupuncture stimulation on the right ST-36 (Zusanli) for 10 consecutive days. We conducted the inhibitory avoidance and forced swimming tests to recognize whether immobilization stress and electroacupuncture have effects on memory and depression. We collected blood samples from the tail of each rat at 30, 60, 90, and 120-minute intervals during the immobilization stress and EA stimulation to measure plasma concentrations of ACTH, corticosterone, melatonin, and norepinephrine induced by immobilization stress and electroacupuncture. Results : There was a significant effect of high frequency on the increase in anamnesis based on the result of the inhibitory avoidance test, but there was no significant effect of decreasing depression based on the result of the forced swim test. Also, there was no significant effect on the response indicated by stress hormones. Conclusions : 1. High frequency electroacupuncture (100Hz) improved anamnesis in immobilization stress states under the inhibitory avoidance task. 2. High frequency electroacupuncture (100Hz) did not reduce depression induced by immobilization stress under the forced swimming test. 3. High frequency electroacupuncture (100Hz) did not decrease stress hormones through blood sampling.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.10a
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• pp.107-112
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• 2003

형상기억합금(shape memory alloy; SMA)은 소성가공을 통하여 원하는 형태로 변형시킨 이후에도(현재로서는 최대 10%미만의 변형) 일정조건의 열을 가하면 원래의 형상으로 복원되는 합금을 말한다. 형상기억효과는 고상(solid state)에서의 금속조직이 오스테나이트(austenite: 이하 A 또는 B2상)로부터 마르텐사이트(martensite: 이하 M 또는 B19'상)로, 다시 역으로 마르텐사이트에서 오스테나이트로의 변태에 기인되는 것으로 밝혀지고 있으며 이러한 변태는 온도유기변태(temperature induced transformation)와 응력유기변태(stress induced transformation)로 분류할 수 있다.(중략)

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.129-136
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• 1999

This research proposes an effective analytical methodology for vertical vibration of three dimensional frame structures including slabs. The consideration of slabs, although allows more precise results, requires large amount of computer time and memory space due to the use of plane stress elements. In consideration of these problems, a method to properly manage nodal points and degrees of freedom is proposed based on matrix condensation technique. Also studied is the use of substructure method to obtain fast and reliable results with simple input data when they are applied to conventional building structures.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.455-456
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• 2008

New CMOS ROM cell is reported in this paper, distinguished from conventional ones in that it can be re-programmed by multi-times. It uses the comparator offset as the physical storage quantity and the MOSFET FN stress effect for offset programming. It demands very low offset for read, and works well in very low voltage. It can become a promising ROM solution for various SoC systems.

• Smart Structures and Systems
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• v.4 no.2
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• pp.123-135
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• 2008

Damping capacity of SMA damping devices is simulated numerically under distinct geometry and loading conditions. Two-dimensional numerical simulations are performed on the basis of a phenomenological model of dynamics of martensite-austenite phase boundaries. Results of the simulations predict the time delay and the value of the stress transferred to other parts of a construction by a damper device.

• Journal of Microbiology and Biotechnology
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• v.22 no.5
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• pp.708-720
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• 2012

In this study, we assessed the effects of ginsenoside Re (GRe) administration on repeated immobilization stress-induced behavioral alterations using the forced swimming test (FST), the elevated plus maze (EPM), and the active avoidance conditioning test (AAT). Additionally, we examined the effect of GRe on the central adrenergic system by observing changes in neuronal tyrosine hydroxylase (TH) immunoreactivity and brain-derived neurotrophic factor (BDNF) mRNA expression in the rat brain. Male rats received 10, 20, or 50 mg/kg GRe (i.p.) 30 min before daily exposures to repeated immobilization stress (2 h/day) for 10 days. Activation of the hypothalamic-pituitary-adrenal (HPA) axis in response to repeated immobilization was confirmed by measuring serum levels of corticosterone (CORT) and the expression of corticotrophin-releasing factor (CRF) in the hypothalamus. Repeated immobilization stress increased immobility in the FST and reduced open-arm exploration in the EPM test. It also increased the probability of escape failures in the AAT test, indicating a reduced avoidance response. Daily administration of GRe during the repeated immobilization stress period significantly inhibited the stress-induced behavioral deficits in these behavioral tests. Administration of GRe also significantly blocked the increase in TH expression in the locus coeruleus (LC) and the decrease in BDNF mRNA expression in the hippocampus. Taken together, these findings indicate that administration of GRe prior to immobilization stress significantly improved helpless behaviors and cognitive impairment, possibly through modulating the central noradrenergic system in rats. These findings suggest that GRe may be a useful agent for treating complex symptoms of depression, anxiety, and cognitive impairment.

• Geomechanics and Engineering
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• v.24 no.6
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• pp.519-529
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• 2021

In coal mining activities, the abutment stress of the coal has to undergo cyclic loading and unloading, affecting the strength and seepage characteristics of coal; additionally, it can cause dynamic disasters, posing a major challenge for the safety of coal mine production. To improve the understanding of the dynamic disaster mechanism of gas outburst and rock burst coupling, triaxial devices are applied to axial pressure cyclic loading-unloading tests under different axial stress peaks and different pore pressures. The existing empirical formula is use to perform a non-linear regression fitting on the relationship between stress and permeability, and the damage rate of permeability is introduced to analyze the change in permeability. The results show that the permeability curve obtained had "memory", and the peak stress was lower than the conventional loading path. The permeability curve and the volume strain curve show a clear symmetrical relationship, being the former in the form of a negative power function. Owing to the influence of irreversible deformation, the permeability difference and the damage of permeability mainly occur in the initial stage of loading-unloading, and both decrease as the number of cycles of loading-unloading increase. At the end of the first cycle and the second cycle, the permeability decreased in the range of 5.777 - 8.421 % and 4.311-8.713 %, respectively. The permeability decreases with an increase in the axial stress peak, and the damage rate shows the opposite trend. Under the same conditions, the permeability of methane is always lower than that of helium, and it shows a V-shape change trend with increasing methane pressures, and the permeability of the specimen was 3 MPa > 1 MPa > 2 MPa.

• Korean Journal of Agricultural Science
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• v.49 no.1
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• pp.137-149
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• 2022

We investigated the effects of Cirsium japonicum var. maackii (CJM) against oxidative stress-induced C6 glial cells and cognitive impairment in mice. To evaluate the anti-oxidative effect of the extract and fractions from CJM, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), reactive oxygen species (ROS), and nitric oxide (NO) assays were conducted in H₂O₂-treated C6 glial cells. Furthermore, we identified the protective mechanisms of CJM with a scopolamine-treated mice model. The results revealed that H₂O₂ decreased the cell viability in C6 glial cells, indicating that H₂O₂ induced oxidative stress in glial cells. However, CJM fractions significantly increased cell viability in H₂O₂-treated C6 glial cells, which suggested that CJM protected against oxidative stress. CJM extract and fractions also reduced ROS and NO production, which were increased by H₂O₂ in C6 glial cells. In particular, the EtOAc fraction from CJM (EACJM) effectively protected against oxidative stress by increasing the cell viability and decreasing ROS and NO. Therefore, we carried out further in vivo experiments with EACJM. Scopolamine caused increases of ROS, thiobarbituric acid reactive substances (TBARS), and NO production. However, EACJM effectively alleviated ROS, TBARS, and NO levels compared to scopolamine-injected mice. In addition, EACJM up-regulated protein expressions of superoxide dismutase and glutathione peroxidase, indicating that EACJM enhanced the antioxidative system. Our results demonstrated that CJM had protective effects against oxidative stress in glial cells and memory dysfunction in mice. Based on these results, we propose that CJM could be a potential AD preventive and therapeutic agent.