• Title/Summary/Keyword: Accumulation, Resistance

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Study of contact resistance using the transmission line method (TLM) pattern for metal of electrode (Cr/Ag & Ni) (TLM pattern을 사용한 Cr/Ag 및 Ni 전극에 따른 접합 저항 연구)

  • Hwang, Min-Young;Koo, Ki-Mo;Koo, Sun-Woo;Oh, Gyu-Jin;Koo, Sang-Mo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.349-349
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    • 2010
  • Great performance of many semiconductor devices requirs the use of low-resistance ohmic contact. Typically, transmission line method (TLM) patterns are used to measure the specific contact resistance between silicon and metal. In this works, we investigate contact resistance for metal dependent (Cr/Ag, Ni) using TLM pattern based on silicon-on-insulator (SOI) wafer. The electrode with Ni linearly increases contact resistance as the pattern distance increase from $15{\mu}m$ to $75{\mu}m$ in accumulation part, but non-linearly increase in inversion part. In additional, the electrode with Cr/Ag linearly increases contact resistance as the pattern distance increase from $15{\mu}m$ to $75{\mu}m$ in inversion part, but non-linearly increase in accumulation part.

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Ginsenosides Rg1 regulate lipid metabolism and temperature adaptation in Caenorhabditis elegans

  • Hao Shi ;Jiamin Zhao ;Yiwen Li ;Junjie Li ;Yunjia Li;Jia Zhang ;Zhantu Qiu ;Chaofeng Wu ;Mengchen Qin ;Chang Liu ;Zhiyun Zeng ;Chao Zhang ;Lei Gao
    • Journal of Ginseng Research
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    • v.47 no.4
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    • pp.524-533
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    • 2023
  • Background: Obesity is a risk factor for aging and many diseases, and the disorder of lipid metabolism makes it prominent. This study aims to investigate the effect of ginsenoside Rg1 on aging, lipid metabolism and stress resistance Methods: Rg1 was administered to Caenorhabditis elegans (C. elegans) cultured in NGM or GNGM. The lifespan, locomotory activity, lipid accumulation, cold and heat stress resistance and related mRNA expression of the worms were examined. Gene knockout mutants were used to clarify the effect on lipid metabolism of Rg1. GFP-binding mutants were used to observe the changes in protein expression Results: We reported that Rg1 reduced lipid accumulation and improved stress resistance in C. elegans. Rg1 significantly reduced the expression of fatty acid synthesis-related genes and lipid metabolism-related genes in C. elegans. However, Rg1 did not affect the fat storage in fat-5/fat-6 double mutant or nhr-49 mutant. Combined with network pharmacology, we clarified the possible pathways and targets of Rg1 in lipid metabolism. In addition, Rg1-treated C. elegans showed a higher expression of anti-oxidative genes and heat shock proteins, which might contribute to stress resistance Conclusion: Rg1 reduced fat accumulation by regulating lipid metabolism via nhr-49 and enhanced stress resistance by its antioxidant effect in C. elegans.

Knockdown of MDR1 Increases the Sensitivity to Adriamycin in Drug Resistant Gastric Cancer Cells

  • Zhu, Chun-Yu;Lv, Yan-Ping;Yan, Deng-Feng;Gao, Fu-Lian
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6757-6760
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    • 2013
  • Gastric cancer is one of the most frequently occurring malignancies in the world. Development of multiple drug resistance (MDR) to chemotherapy is known as the major cause of treatment failure for gastric cancer. Multiple drug resistance 1/P-glycoprotein (MDR1/p-gp) contributes to drug resistance via ATP-dependent drug efflux pumps and is overexpressed in many solid tumors including gastric cancer. To investigate the role of MDR1 knockdown on drug resistance reversal, we knocked down MDR1 expression using shRNA in drug resistant gastric cancer cells and examined the consequences with regard to adriamycin (ADR) accumulation and drug-sensitivity. Two shRNAs efficiently inhibited mRNA and protein expression of MDR1 in SGC7901-MDR1 cells. MDR1 knockdown obviously decreased the ADR accumulation in cells and increased the sensitivity to ADR treatment. Together, our results revealed a crucial role of MDR1 in drug resistance and confirmed that MDR1 knockdown could reverse this phenotype in gastric cancer cells.

A Study on Contact Resistance of the Nano-Scale MOSFET (Nano-Scale MOSFET 소자의 Contact Resistance에 대한 연구)

  • 이준하;이흥주
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.5 no.1
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    • pp.13-15
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    • 2004
  • The current driven in an MOSFET is limited by the intrinsic channel resistance. All the other parasitic elements in a device structure play a significant role and degrade the device performance. These other resistances need to be less than 15% of the channel resistance. To achieve the requirements, we should investigate the methodology of separation and quantification of those resistances. In this paper, we developed the extraction method of resistances using calibrated TCAD simulation. The resistance of the extension region is also partially determined by the formation of a surface accumulation region that forms under the gate in the tail region of the extension profile. This resistance is strongly affected by the abruptness of the extension profile because the steeper the profile is, the shorter this accumulation region will be.

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A Simple Model for Parasitic Resistances of LDD MOSFETS (LDD MOSFET의 기생저항에 대한 간단한 모형)

  • Lee, Jung-Il;Yoon, Kyung-Sik;Lee, Myoung-Bok;Kang, Kwang-Nham
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.11
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    • pp.49-54
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    • 1990
  • In this paper, a simple model is presented for the gate-voltage dependence of the parasitic resistance in MOSFETs with the lightly-doped drain (LDD) structure. At the LDD region located under the gate electrode, an accumulation layer is formed due to the gate voltage. The parasitic resistance of the source side LDD in the channel is treated as a parallel combination of the resistance of the accumulation layer and that of the bulk LDD, which is approximated as a spreading resistance from the end of the channel inversion layer to the ${n^+}$/LDD junction boundary. Also the effects of doping gradients at the junction are discussed. As result of the model, the LDD resistance decreases with increasing the gate voltage at the linear regime, and increase quasi-linearly with the gate voltage at the saturation regime, considering th velocity saturation both in the channel and in the LDD region. The results are in good agreement with experimental data reported by others.

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The Relationship between Lipid Accumulation Product, Insulin Resistance and Obesity in Korean Adults (대한민국 성인에서 한국 성인의 지질 축적 지수와 인슐린 저항성 및 비만의 관련성)

  • Yoon, Hyun
    • Korean Journal of Clinical Laboratory Science
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    • v.54 no.2
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    • pp.149-156
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    • 2022
  • Lipid accumulation product (LAP) is a new index reflecting central lipid accumulation and is known to be a strong independent indicator for identifying the risk of cardiovascular disease (CVD) or diabetes mellitus (DM). This study was conducted to assess the relationship between the homeostasis model assessment of insulin resistance (HOMA-IR) and LAP according to the presence or absence of obesity in Korean adults. The study was carried out using data from the 2019 Korean National Health and Nutrition Examination Survey (KNHANES) and included 6,090 adults aged 20 years or older. There were several key findings. First, after adjusting for related variables, the mean of the HOMA-IR levels (M±SE, 95% confidence interval) was positively associated with the quartiles of LAP in the overall population (P<0.001), non-obese (P<0.001) or obese groups (P<0.001). Second, in all the groups (overall population, non-obese and obese groups), the mean value of the fasting blood glucose (all, P<0.001), insulin (all, P<0.001), and the metabolic syndrome score (all, P<0.001) increased with the increasing quartiles of LAP. Insulin resistance was thus positively associated with an increase in the LAP in Korean adults with or without obesity.

Scopoletin Production Related to Induced Resistance of Tobacco Plants Against Tobacco mosaic virus

  • Kim, Young-Ho;Choi, Do-Il;Yeo, Woon-Hyung;Kim, Young-Sook;Chae, Soon-Yong;Park, Eun-Kyung;Kim, Sang-Seock
    • The Plant Pathology Journal
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    • v.16 no.5
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    • pp.264-268
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    • 2000
  • A fluorescent material was accumulated in inoculated leaves showing necrotic local lesions of tobacco plants with N gene, Nicotiana tabacum cvs. Xanthi-nc NN, Samsun NN, Burley 21 and KF 114, and N. glutinosa, and Datura stramonium at the early growth stages by the inoculation of Tobacco mosaic virus (TMV). It was identified as a coumarin phytoalexin, scopoletin. Although the material was most prominently produced in TMV-inoculated tobacco leaves with local necrotic lesions, its accumulation was also noted in uninoculated leaves of TMV-inoculated plants. Its accumulation was somewhat greater in high resistance-induced leaves than low resistance-induced and intact leaves. Scopoletin treatment induced the expression of a pathogenesis-related protein, PR-1, prominently at the concentration of 500 or 1000 ${\mu}$g/ml. This suggests that scopoletin is a phytoalexin abundantly accumulating in N gene-containing resistant plants in response to TMV infection, and may be related to hypersensitive responses (HR) and systemic acquired resistance (SAR) in the resistant tobacco plants.

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Induction of Resistance by TMV Infection in Capsicum annuum Against Phytophthora Blight (TMV 감염에 의한 고추의 역병 저항성 유도)

  • 이성희;이주연;차재순
    • Korean Journal Plant Pathology
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    • v.14 no.4
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    • pp.319-324
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    • 1998
  • Induction of systemic acquired resistance (SAR) against phytophthora blight and pathogenesis-related (PR) protein accumulation by TMV infection in pepper plant (Capsicum annuum cv. Nockwang) were examined to understand the mechanism of the systemic acquired resistance in pepper plant. The zoospore suspension of Phytophthora capsici was inoculated on stem of pepper plant in which TMV-pepper strain had been inoculated on fully expanded upper leaves, and thephytopha blight incidence was examined. Both disease severity and lesion length of phytophthora blight were much smaller in TMV pre-inoculated pepper plant than in uninoculated control plants. The phytophthora blight incidence was decreased about 50% in the TMV pre-inoculated pepper, compared to the uninoculated control plant at 10 days after P. capsici inoculation. Accumulation of PR1 and PR5 proteins in intercellular fluid of TMV-inoculated and uninoculated upper leaves were monitored by immuno-blot with tobacco P1b and PR5a, antibody during induction of SAR. PR1 and PR5 were detected from 24 hours after TMV inoculation in both TMV-inoculated and uninouclated upper leaves, and increased rapidly in TMV-inoculation in uninoculated upper leaves were defoliated. PR5 could be detected upto 20 days after TMV inoculation in uninoculated upper leaves. These results suggest that TMV infection induces SAR against phytophthora blight in pepper plant, and that PR proteins are accumulated very rapidly during induction of SAR and maintained for quite long time in pepper plant.

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Platinum Transporters and Drug Resistance

  • Choi, Min-Koo;Kim, Dae-Duk
    • Archives of Pharmacal Research
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    • v.29 no.12
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    • pp.1067-1073
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    • 2006
  • Cisplatin, a platinum coordinated complex, is a widely used antineoplastic agent for the treatment of metastatic tumors of the testis, metastatic ovarian tumors, lung cancer, advanced bladder cancer and many other solid tumors. The cytotoxic action of the drug is often thought to be associated with its ability to bind DNA to form cisplatin-DNA adducts. The development of resistance to cisplatin during treatment is common and constitutes a major obstacle to the cure of sensitive tumors. Although to understand the clinically relevant mechanisms of resistance, many studies have been aimed at clarifying the biochemical/molecular alterations of cisplatin-resistance cells, these studies did not conclusively identify the basis of cellular resistance to cisplatin. In this review, cisplatin resistance was discussed in terms of the relevant transporters, such as copper transporters (CTRs), organic cation transporters (OCTs) and multi-drug resistance related transporters (MDRs). These transporters seem to be contributed to cisplatin resistance through the reduction of drug accumulation in the cell. Better understanding the mechanism of cisplatin resistance associated with transporters will provide the useful informations for overcoming the cisplatin resistance.

Optimization of 4H-SiC Superjunction Accumulation MOSFETs by Adjustment of the Thickness and Doping Level of the p-Pillar Region (p-Pillar 영역의 두께와 농도에 따른 4H-SiC 기반 Superjunction Accumulation MOSFET 소자 구조의 최적화)

  • Jeong, Young-Seok;Koo, Sang-Mo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.6
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    • pp.345-348
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    • 2017
  • In this work, static characteristics of 4H-SiC SJ-ACCUFETs were obtained by adjusting the p-pillar region. The structure of this SJ-ACCUFET was designed by using a two-dimensional simulator. The static characteristics of SJ-ACCUFET, such as the breakdown voltages, on-resistance, and figure of merits, were obtained by varying the p-pillar doping concentration from $1{\times}10^{15}cm^{-3}$ to $5{\times}10^{16}cm^{-3}$ and the thickness from $0{\mu}m$ to $9{\mu}m$. The doping concentration and the thickness of p-pillar region are closely related to the break down voltage and on-resistance and threshold voltages. Hence a silicon carbide SJ-ACCUFET structure with highly intensified breakdown voltages and low on-resistances with good figure of merits can be achieved by optimizing the p-pillar thickness and doping concentration.