• Applied Biological Chemistry
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• v.50 no.1
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• pp.63-67
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• 2007

The neuroprotective effect of methanolic extracts from Dendrobium nobile Lindl. (DME) against $H_{2}O_{2}$-induced neurotoxicity in PC12 cells was investigated. The treatment of PC12 cells with various DME concentrations under $H_{2}O_{2}$ resulted in the induction of protective effect in a dose-dependent manner, as determined by the results of an MTT reduction assay, an LDH release assays, and a morphological assay. Interestingly, we also detected reduction of apoptotic bodies and inhibition of caspase-3 activity by DME in $H_{2}O_{2}$-indeced PC12 cells. These data show that the neuroprotective effect of DME against PC12 cells might be related to the suppression of caspase-3 activation. Therefore, these results suggest that DME could be a new potential candidate as chemotherapeutic agents against neuronal diseases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6425-6431
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• 2015

Invertase, that hydrolyzes sucrose into glucose and fructose, plays a great role in carbohydrate reallocation between the photosynthetic source tissue and various sink tissues. Invertase also occurs in a variety of isoforms for various functions in plants. Insoluble invertases were extracted only in buffer solutions containing high concentrations of salt. Within these classes, acid invertase has an optimum activity at acidic pH (pH 4-5). Induction of insoluble acid invertase (INAC-INV) in leaf, stem, and root tissues in response to physical wounding has been investigated. To detect the localization of INAC-INV within the plant, immunolocalization has been performed. In this study, the accumulation of INAC-INV was noticeable to reach maximum levels on 72 hr after mechanical injuries. INAC-INV was induced in wounded leaves 3 times more than control leaves. Immunolocalization results showed that INAC-INV accumulated in wall appositions and intercellular spaces. INAC-INV was also localized at sieve cell walls in phloem tissues close to the site of wounding. Taken together, this study suggested that INAC-INV induction upon wounding injuries can play a role on responses to the high energy demand for wound healing process.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.456-456
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• 2010

CMOS 소자가 서브마이크론($0.1\;{\mu}m$) 이하로 스케일다운 되면서 단채널 효과(short channel effect), 게이트 산화막(gate oxide)의 누설전류(leakage current)의 증가와 높은 직렬저항(series resistance) 등의 문제가 발생한다. CMOS 소자의 구동전류(drive current)를 높이고, 단채널 효과를 줄이기 위한 가장 효율적인 방법은 소스 및 드레인의 얕은 접합(shallow junction) 형성과 직렬 저항을 줄이는 것이다. 플라즈마 도핑 방법은 플라즈마 밀도 컨트롤, 주입 바이어스 전압 조절 등을 통해 저 에너지 이온주입법보다 기판 손상 및 표면 결함의 생성을 억제하면서 고농도로 얕은 접합을 형성할 수 있다. 그리고 얕은 접합을 형성하기 위해 주입된 불순물의 활성화와 확산을 위해 후속 열처리 공정은 높은 온도에서 짧은 시간 열처리하여 불순물 물질의 활성화를 높여주면서 열처리로 인한 접합 깊이를 얕게 해야 한다. 그러나 접합의 깊이가 줄어듦에 따라서 소스 및 드레인의 표면 저항(sheet resistance)과 접촉저항(contact resistance)이 급격하게 증가하는 문제점이 있다. 이러한 표면저항과 접촉저항을 줄이기 위한 방안으로 실리사이드 박막(silicide thin film)을 형성하는 방법이 사용되고 있다. 본 논문에서는 (100) p-type 웨이퍼 He(90 %) 가스로 희석된 $PH_3$(10 %) 가스를 사용하여 플라즈마 도핑을 실시하였다. 10 mTorr의 압력에서 200 W RF 파워를 인가하여 플라즈마를 생성하였고 도핑은 바이어스 전압 -1 kV에서 60 초 동안 실시하였다. 얕은 접합을 형성하기 위한 불순물의 활성화는 ArF(193 nm) excimer laser를 통해 $460\;mJ/cm^2$의 에니지로 열처리를 실시하였다. 그리고 낮은 접촉비저항과 표면저항을 얻기 위해 metal sputter를 통해 TiN/Ti를 $800/400\;{\AA}$ 증착하고 metal RTP를 사용하여 실리사이드 형성 온도를 $650{\sim}800^{\circ}C$까지 60 초 동안 열처리를 실시하여 $TiSi_2$ 박막을 형성하였다. 그리고 $TiSi_2$의 두께를 측정하기 위해 TEM(Transmission Electron Microscopy)을 측정하였다. 화학적 결합상태를 분석하기 위해 XPS(X-ray photoelectronic)와 XRD(X-ray diffraction)를 측정하였다. 접촉비저항, 접촉저항과 표면저항을 분석하기 위해 TLM(Transfer Length Method) 패턴을 제작하여 I-V 특성을 측정하였다. TEM 측정결과 $TiSi_2$의 두께는 약 $580{\AA}$ 정도이고 morphology는 안정적이고 실리사이드 집괴 현상은 발견되지 않았다. XPS와 XRD 분석결과 실리사이드 형성 온도가 $700^{\circ}C$에서 C54 형태의 $TiSi_2$ 박막이 형성되었고 가장 낮은 접촉비저항과 접촉저항 값을 가진다.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.325-330
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• 2007

This study was to determine whether canine model which produce acute permanent joint instability in short period without postoperative exercise have a degenerative changes and also evaluated its suitability as an appropriate animal OA models. Ten skeletally mature beagle dogs underwent a unilateral surgical transection of the cranial cruciate ligament and, the medial collateral ligament as well as a medial meniscectomy. The contra-lateral joint was used as control. After 12 weeks, After 12 weeks, the amount of joint damage, inflammation and biochemical change of synovial fluid was evaluated. Histological analysis showed chondrocyte clone formation, hypertrophy of the cartilage and moderate loss of proteoglycans in the experimental joints compared to control joints. In addition, the synovial inflammation in the experimental joints was observed. Biochemical analysis of SF showed significantly increased MMP (matrix metalloproteinase) -2 and -9 in experimental joints compared to control joints. This canine OA model shows the characteristics of degenerative joint disease, and may have a advantages of reducing the time and cost because postoperative exercise is not needed in this OA model.

• Journal of Oriental Neuropsychiatry
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• v.22 no.4
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• pp.201-218
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• 2011

Objectives : The aim of this study was to investigate the effects of Guibi-Tang(GBT) on focal brain ischemic injury induced by intraluminal filament insertion in rats. Methods : The ischemia was induced by intraluminal filament insertion into middle cerebral artery. Sprague-Dawley rats were divided into five groups, normal group(n=8); control group was ischemia induced and no treatment(n=8); GBT 1X group was ischemia induced and administrated 42.2 mg/ml/kg of Guibi-Tang orally(n=8); GBT 3X group was ischemia induced and administrated 126.6 mg/ml/kg of Guibi-Tang orally(n=8); GBT 6X group was ischemia induced and administrated 253.2 mg/ml/kg of Guibi-Tang orally(n=8) for 21 days. mGluR5, Bax, Bcl-2 and cytochrome C were investigated to observe the effects of Guibi-Tang on apoptosis. The effects of Guibi-Tang on neuroprotective/apoptotic agents in cresyl violet, choline acetyltranferase(ChAT) with ischemic injury were investigated. Results : The intensity of mGluR5 mRNA in the hippocampal CA1 was increased in normal and GBT(Guibi-Tang) 1X groups compared with the control group. The intensity of Bax mRNA in the hippocampal CA1 was decreased in normal and GBT 1X groups compared with the control group. However it was increased unexpectedly in GBT 3X group. The intensity of Bcl-2 mRNA in the hippocampal CA1 was increased in normal and GBT 1X groups compared with the control group. The intensity of Bax/Bcl-2 ratio in the hippocampal CA1 was decreased in normal and GBT 1X groups compared with the control group. The intensity of cytochrome C protein in the hippocampal CA1 was decreased in normal, GBT 1X and GBT 6X groups compared with the control group. The density of neurons stained by cresyl violet and ChAT was increased in normal and GBT 1X groups compared with the control group. Conclusions : These results suggest that Guibi-Tang may have protective effect on vascular dementia.

• Journal of Life Science
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• v.26 no.7
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• pp.847-854
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• 2016

Cordycepin, a derivative of the nucleoside adenosine, is one of the active components extracted from fungi of genus Cordyceps, and has been shown to have many pharmacological activities. In this study, we investigated the effects of cordycepin on proliferation and apoptosis of human gastric cancer AGS cells, and its possible mechanism of action. Treatment of cordycepin resulted in significant decrease in cell viability of AGS cells in a concentration-dependent manner. A concentration-dependent apoptotic cell death was also measured by agarose gel electrophoresis and flow cytometery analysis. Molecular mechanistic studies of apoptosis unraveled cordycepin treatment resulted in an enhanced expression of tumor necrosis factor-related apoptosis-inducing ligand, death receptor 5 and Fas ligand. Furthermore, up-regulation of pro-apoptotic Bax, and down-regulation of anti-apoptotic Bcl-2 and Bcl-xL expression were also observed in cordycepin-treated AGS cells. These were followed by activation of caspases (caspase-9, -8 and -3), subsequently leading to poly (ADP-ribose) polymerase cleavage. Taken together, these findings indicate that cordycepin induces apoptosis in AGS cells through regulation of multiple apoptotic pathways, including death receptor and mitochondria. Although further mechanical studies are needed, our results revealed that cordycepin can be regarded as a new effective and chemopreventive compound for human gastric cancer treatment.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1130-1133
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• 2002

Domoic acid, and amnesic shellfish poison, is a neurotoxin frequently found in shellfishes. Guidance level for the consumable shellfish has been established as $20\;{\mu}g$ domoic acid/g by Health and Welfare Canada and U.S. FDA. Domoic acid is produced by pennate diatom, a Nitzschia pungens f. multiseries ingested by the shellfish. Content of domoic acid in shellfish samples collected along the Korean shoreline from May to December of 1999 was analyzed. The collection included 1 Gastropoda (Murex shell) and 11 Bivalvias (oyster, little neck clam, orient hard clam, venus clam, surf clam, ark shell, hard-shelled mussel, pen shell, jack-knife clam, pink butterfly shell, and granulated ark shell). Samples were homogenized, extracted with 50% methanol, filtered, and analyzed by reversed-phase liquid chromatography at 242 nm with mobile phase consisting of 10% acetonitrile and 0.1% trifluoroacetic acid. Recovery of the HPLC analysis was 95.80% (${\pm}1.09$). All tested samples showed no domoic acid at the detection limit of 50 ng/g.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.461-468
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• 2000

To investigate the antigenotoxicity of Korean mistletoe using Comet assay, the crude extract was divided into 4 fractions, i.e. fraction I (MW range over 14,000), fraction II $(8,000{\sim}14,000)$, fraction III $(3,500{\sim}8,000)$, and fraction IV (below 3,500) by molecular weight fractionation. In the non-tumoral 3T3 cells, fraction IV could reduce DNA damage induced by MNNG in a dose dependent pattern while fraction I and III which were known to contain lectins and viscotoxins, respectively, did not show the activity. By heat treatment, the antigenotoxic activity of faction IV, though was gradually diminished according to heating time, was found to be maintained significantly. From the Sephadex G-25 gel filtration chromatography, a more purified fraction responsible for the activity of faction IV was obtained from the latter part of total elute. Therefore, it was concluded that the antigenotoxic components of Korean mistletoe were water soluble substances of MW below 1,000 and there is a possibility of utilization as a material of functional foods for chemoprevention.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.213-226
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• 2011

This study was performed to investigate the effect of essential oils and ethanolic extracts of approximately 650 plant species on acetylcholine esterase (AChE) enzyme activity using Ellman's colorimetric method in 96-well microplates. The results showed that the ethanolic extracts from twig of Sophora subprostrata, twig of Phellodendron amurense, seed of Corylopsis coreana, and essential oil (EO) from Citrus paradisi, Cupressus sempervirens, Ocimum basilicum, Pinus sylvestris and Rosmarinus officinalis inhibited more than 80% of AChE activity. Among these, EO from Pinus sylvestris, C. sempervirens and C paradisi exhibited higher values of AChE inhibitory activity, which were 75, 84 and 99% at a concentration of 50 ug/ml, respectively. Finally, EO from C paradisi (grapefruit, GEO) showed the highest inhibitory activity towards AChE, which showed 91% of inhibition at a concentration of 20 ug/ml. We also examined the anti-dementia effects of GEO in mouse by passive avoidance test and Morris water maze test. The model mouse (male, ICR) of dementia (negative control) was induced by administration of scopolamine (1 mg/kg body weight). The latency time of sample group administrated with GEO (100 mg/kg, p.o.) increased significantly as compared with negative control on passive avoidance test. There were significant recovery from the scopolamine-induced deficits on learning and memory in water maze test through daily administrations with GEO (100 mg/kg, p.o.). From these results, we conclude that GEO treatment might enhance the cognitive function, suggesting that the EO of C. paradis may be a potential candidate for improvement of perceptive ability and dementia.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.103-109
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• 2005

UV irradiation leads to distinct changes in skin connective tissue, which is degradation of collagen. Many of these alterations in the extracellular matrix are mediated by matrix metalloproteinases. In this study, to develop a new anti-aging agent, we screened the antioxidant activity of solvent fractions from ethanolic extract of Melothria Heterophylla. Among the four solvent fractions tested, the EtOAc fraction exhibited the highest antioxidant activity. It was investigated the inhibitory effect of the EtOAc fraction on the expression and activity of MMP-1 in UVA-irradiated human dermal fibroblasts. The EtOAc fraction inhibited the activity of MMP-1 in a dose dependent manner with the $IC_{50}$ values of $9{\mu}g/mL$. Also, UVA-induced MMP-1 expression was reduced about $90\%$ by $100{\mu}g/mL$ of the EtOAc fraction but MMP-1 mRNA expression was not inhibited. Therefore, we conclude that the EtOAc fraction significantly inhibits MMP-1 expression at the protein level. From these results, we suggest that the EtOAc fraction from M. heterophylla could be used as a new anti-aging agent for the photo-damaged skin.