• Title/Summary/Keyword: Material effects

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Anti-proliferative Effects of Atractylis lancea (Thunb.) DC. via Down-regulation of the c-myc/hTERT/Telomerase Pathway in Hep-G2 Cells

  • Guo, Wei-Qiang;Li, Liang-Zhi;He, Zhuo-Yang;Zhang, Qi;Liu, Jia;Hu, Cui-Ying;Qin, Fen-Ju;Wang, Tao-Yun
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6363-6367
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    • 2013
  • Atractylis lancea (Thunb.) DC. (AL), an important medicinal herb in Asia, has been shown to have anti-tumor effects on cancer cells, but the involved mechanisms are poorly understood. This study focused on potential effects and molecular mechanisms of AL on the proliferation of the Hep-G2 liver cancer cell line in vitro. Cell viability was assessed by MTT test in Hep-G2 cells incubated with an ethanol extract of AL. Then, the effects of AL on apoptosis and cell cycle progression were determined by flow cytometry. Telomeric repeat amplification protocol (TRAP) assays was performed to investigate telomerase activity. The mRNA and protein expression of human telomerase reverse transcriptase (hTERT) and c-myc were determined by real-time RT-PCR and Western blotting. Our results show that AL effectively inhibits proliferation in Hep-G2 cells in a concentrationand time-dependent manner. When Hep-G2 cells were treated with AL after 48h,the $IC_{50}$ was about 72.1 ${\mu}g/mL$. Apoptosis was induced by AL via arresting the cells in the G1 phase. Furthermore, AL effectively reduced telomerase activity through inhibition of mRNA and protein expression of hTERT and c-myc. Hence, these data demonstrate that AL exerts anti-proliferative effects in Hep-G2 cells via down-regulation of the c-myc/hTERT/telomerase pathway.

The Properties of Photoinduced Birefringence in Chalcogenide Thin Films by the Electric Field Effects (전계효과에 의한 칼코게나이드 박막에서의 광유기 복굴절 특성)

  • 장선주;박종화;여철호;정홍배
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.1
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    • pp.58-63
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    • 2001
  • We have investigated the photoinduced birefrinence by the electric field effects in chalcogenide thin films. The electric field effects have investigated the various applied bias voltages(forward and reverse) in chalcogenide thin films. A pumping (inducing) and a probing bean were using a linearly polarized He-Ne laser light (633nm) and semiconductor laser light (780nm), respectively. The result was shown that the birefringence had a higher value in DC +2V than the others, Also, we obtained the birefringence in the electric field effects by various voltages. In addition, we have discussed the anisotropy property of chalcogenide thin films by the electric field effects.

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Analysis of Effects of Stiffness Increment Factors for Deciding the Initial Structural System of Tall Buildings (초고층건물 초기 구조시스템 선정을 위한 강성증가요인 효과 분석)

  • Lee, Jae-Cheol;Jung, Jong-Hyun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.857-862
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    • 2007
  • The purpose of this research is to compare the stiffness increment effects with the floor plan shapes by the stiffness increment factors. For this, we generated the standard floor plans with Box and T type shapes. Then applied the stiffness increment factors -outrigger, material strength, member section- to those floor plans, and generated several alternative analysis models that make the effects of the factors to the lateral displacement exposed. Finally, we analyzed the stiffness increment effects and compared with each other by the stiffness increment factors. As a result, we found that the increment effects have not influence to floor plan shapes, and orders of stiffness increment effects are outrigger, core wall and material strength. We expect that the results of this study could be effectively utilized in the schematic structural design of tall buildings.

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Evaluation of Material Properties for Yonggwang Nuclear Piping Systems (III) - Main Steam System - (영광원자력 배관소재의 재료물성치 평가 (III) -주증기계통-)

  • 김영진;석창성;김종욱
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.6
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    • pp.1460-1468
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    • 1995
  • The objective of this paper is to evaluate the material properties of SA106 Gr. C carbon steel and its associated weld manufactured for main steam system of Yonggwang 3,4 nuclear generating stations. A total of 43 tensile and 35 fracture toughness tests were performed and the effects of various parameters such as pipe size, crack plane orientation, test temperature, welding on material properties were discussed. Test results show that the effects of crack plane orientation, test temperature, and welding on fracture toughness were significant while the effects of pipe size, specimen orientation and test temperature on tensile properties were negligible. Especially the dependence of J-R curves on the crack plane orientation appears to be the characteristics of carbon steel.

Evaluation of Material Properties for Yonggwang Nuclear Piping Systems(II) - Safety Injection System- (영광원자력 배관소재의 재료물성치 평가 (II) -안전주입계통-)

  • 김영진;석창성;장윤석
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.6
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    • pp.1451-1459
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    • 1995
  • The objective of this paper is to evaluate the material properties of SA312 TP316 and SA312 TP304 stainless steels and their associated welds manufactured for safety injection system of Yonggwang 3,4 nuclear generating stations. A total of 62 tensile tests and 46 fracture toughness tests were conducted and the effects of various parameters such as pipe size, crack plane orientation, tests were conducted and the effects of various parameters such as pipe size, crack plane orientation, test temperature, welding on material properties were discussed. Test results show that the effect of test temperature on fracture toughness was significant while the effects of pipe size and crack plane orientation on fracture toughness were negligible. Fracture toughness of the weld metal was in general higher than that of the base metal.

The Memory Effects of a Carbon Nanotube Nanodevice

  • Lee Chi-Heon;Kim Ho-Gi
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.4
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    • pp.26-29
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    • 2003
  • To discover electrical properties of individual single wall nanotube(SWNT), a number of SWNT-based tubeFETs have been fabricated. The device consists of a single semiconducting SWNT on an insulating substrate, contacted at each end by metal electrodes. It presents high transconductances, and charge storage phenomenon, which is the operations of injecting electrons from the nanotube channel of a tubeFET into charge traps on the surface of the $SiO_2$ gate dielectric, thus shifting the threshold voltage. This phenomenon can be repeated many times, and maintained for the hundreds of seconds at room temperature. We will report this phenomenon as the memory effects of the SWNT, and attempt to use this property for the memory device.

SHS of Oxide Systems Based on MCR of Quartz Modified by Organometallic Compounds

  • Soh, Dea-Wha;Tlek, Ketegenov;Z.A., Mansurov
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.666-669
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    • 2002
  • The differences of the effects of mechanical substance pre-activation in the mills with divers force effect schemes on the self-propagating high temperature synthesis (SHS) of the $SiO_2$ + 37.5% Al system were investigated. The power saturation of activated material state are estimated referring on the variations of dilatometry curve paths. The effects of activation time on the temperature of sample self-ignited in the furnace, combustion temperature and completeness of the quartz reaction with aluminium were determined. The enhancing effects of organic modifiers of quartz particle surfaces on the further SHS synthesis development were shown.

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The effects of dopant additions on the NTC thermistor based on Fe$_2$O$_3$ (Fe$_2$O$_3$계 NTC thermistor의 첨가물 영향)

  • 강희복;이동희;김상영;한성진;성영권
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1989.06a
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    • pp.93-96
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    • 1989
  • NTC thermistor was prepared by adding TiO$_2$and MnO$_2$on Fe$_2$O$_3$and the effects of additions were investigated. And the effects of compating pressure, sintering temperature, and sintering time were also experimented. Fe$_2$O$_3$is insulator in stoichiometric state and will be semiconductor by introducing Ti$^{+4}$, Sn$^{+4}$. These semiconducting material will show large negative temperature coeffecients and can be used as NTC thermistor.tor.

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Effects of Surface Charges on Hydrophobicity and Surface Potential Decay with Various Surface States of Silicone Rubber for Outdoor Insulator (옥외용 실리콘 절연재료의 발수성에 미치는 표면전하의 영향과 표면 상태에 따른 표면전위 감쇠)

  • 연복희;박충렬;허창수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.8
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    • pp.678-686
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    • 2002
  • This paper presents the effects of accumulation of surface charges on hydrophobic level and the changes of surface potential decay with various artificial environment treatments on high temperature vulcanized (HTV) silicone rubber used for outdoor insulating material. For this study, the charging apparatus by corona discharge, in which grid electrode was installed between the main corona and ground electrode, was used. From this study, it was found that the accumulation of surface charges above a critical surface potential on silicone insulating materials could lead to the temporary loss of surface hydrophobicity. In addition, corona stress and water absorption stress increase the decay rate of surface charges of HTV silicone rubber, while ultraviolet (UV) stress causes longer decay time. We could conclude that the effects of surface charges on hydrophobicity level and the changes of surface state by various artificial treatments were found through a trend of surface potential decay.

Post-buckling responses of functionally graded beams with porosities

  • Akbas, Seref D.
    • Steel and Composite Structures
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    • v.24 no.5
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    • pp.579-589
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    • 2017
  • The objective of this work is to analyze post-buckling of functionally graded (FG) beams with porosity effect under compression load. Material properties of the beam change in the thickness direction according to power-law distributions with different porosity models. It is known that post-buckling problems are geometrically nonlinear problems. In the nonlinear kinematic model of the beam, total Lagrangian finite element model of two dimensional (2-D) continuum is used in conjunction with the Newton-Raphson method. In the study, the effects of material distribution, porosity parameters, compression loads on the post-buckling behavior of FG beams are investigated and discussed with porosity effects. Also, the effects of the different porosity models on the FG beams are investigated in post-buckling case.