• 제목/요약/키워드: Ion Channel

검색결과 445건 처리시간 0.034초

Fabrication of excimer laser annealed poly-si thin film transistor by using an elevated temperature ion shower doping

  • Park, Seung-Chul;Jeon, Duk-Young
    • E2M - 전기 전자와 첨단 소재
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    • 제11권11호
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    • pp.22-27
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    • 1998
  • We have investigated the effect of an ion shower doping of the laser annealed poly-Si films at an elevated substrate temperatures. The substrate temperature was varied from room temperature to 300$^{\circ}C$ when the poly-Si film was doped with phosphorus by a non-mass-separated ion shower. Optical, structural, and electrical characterizations have been performed in order to study the effect of the ion showering doping. The sheet resistance of the doped poly-Si films was decreased from7${\times}$106 $\Omega$/$\square$ to 700 $\Omega$/$\square$ when the substrate temperature was increased from room temperature to 300$^{\circ}C$. This low sheet resistance is due to the fact that the doped film doesn't become amorphous but remains in the polycrystalline phase. The mildly elevated substrate temperature appears to reduce ion damages incurred in poly-Si films during ion-shower doping. Using the ion-shower doping at 250$^{\circ}C$, the field effect mobility of 120 $\textrm{cm}^2$/(v$.$s) has been obtained for the n-channel poly-Si TFTs.

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[ 0.1\;μm ] SOI-MOSFET의 적정 채널도핑농도에 관한 시뮬레이션 연구 (Investigation of Optimal Channel Doping Concentration for 0.1\;μm SOI-MOSFET by Process and Device Simulation)

  • 최광수
    • 한국재료학회지
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    • 제18권5호
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    • pp.272-276
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    • 2008
  • In submicron MOSFET devices, maintaining the ratio between the channel length (L) and the channel depth (D) at 3 : 1 or larger is known to be critical in preventing deleterious short-channel effects. In this study, n-type SOI-MOSFETs with a channel length of $0.1\;{\mu}m$ and a Si film thickness (channel depth) of $0.033\;{\mu}m$ (L : D = 3 : 1) were virtually fabricated using a TSUPREM-4 process simulator. To form functioning transistors on the very thin Si film, a protective layer of $0.08\;{\mu}m$-thick surface oxide was deposited prior to the source/drain ion implantation so as to dampen the speed of the incoming As ions. The p-type boron doping concentration of the Si film, in which the device channel is formed, was used as the key variable in the process simulation. The finished devices were electrically tested with a Medici device simulator. The result showed that, for a given channel doping concentration of $1.9{\sim}2.5\;{\times}\;10^{18}\;cm^{-3}$, the threshold voltage was $0.5{\sim}0.7\;V$, and the subthreshold swing was $70{\sim}80\;mV/dec$. These value ranges are all fairly reasonable and should form a 'magic region' in which SOI-MOSFETs run optimally.

Vibrio vulnificus Cytolysin Forms Anion-selective Pores on the CPAE Cells, a Pulmonary Endothelial Cell Line

  • Choi, Bok-Hee;Park, Byung-Hyun;Kwak, Yong-Geun
    • The Korean Journal of Physiology and Pharmacology
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    • 제8권5호
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    • pp.259-264
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    • 2004
  • Cytolysin produced by Vibrio vulnificus has been incriminated as one of the important virulence determinants in V. vulnificus infection. Ion selectivity of cytolysin-induced pores was examined in a CPAE cell, a cell line of pulmonary endothelial cell, using inside-out patch clamp techniques. In symmetrical NaCl concentration (140 mM), intracellular or extracellular application of cytolysin formed ion-permeable pores with a single channel conductance of $37.5{\pm}4.0$ pS. The pore currents were consistently maintained after washout of cytolysin. Replacement of $Na^+$ in bath solution with monovalent ions $(K^+,\;Cs^+\;or\;TEA^+)$ or with divalent ions $(Mg^{2+},\;Ca^{2+})$ did not affect the pore currents. When the NaCl concentration in bath solution was lowered from 140 to 60 and 20 mM, the reversal potential shifted from 0 to -11.8 and -28.2 mV, respectively. The relative permeability of the cytolysin pores to anions measured at $-40\;mV\;was\;Cl^-\;=\;NO_2^-\;{\geq}\;Br^-\;=\;I^-\;> \;SCN^-\;>\;acetate^-\;>\;isethionate^-\;>\;ascorbic acid^-\;>\;EDTA^{2-},$ in descending order. The cytolysin-induced pore current was blocked by $CI^-$ channel blockers or nucleotides. These results indicate that V. vulnificus cytolysin forms anion-selective pores in CPAE cells.

개와 사람의 선천성 심장 전도장애에 대한 분자 유전학적 이해 (Molecular Genetics of Inherited Cardiac Conduction Defects in Humans and Dogs)

  • Hyun, Changbaig
    • 한국임상수의학회지
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    • 제21권2호
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    • pp.219-228
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    • 2004
  • 심장 전도계에 관련된 심장 질환은 심장 전도계의 원발성 결함이나 형태학적 심장 질환 및 약물 중독 같은 속발성 원인에 의해 발생한다. 특히 선천성 심장 전도 장애의 경우, 이온 채널, 이온 채널에 관련한 세포질성 단백질, gap-junction 단백질, transcription factors (심장 발생에 관련된 유전자들) 및 kinase subunit을 전사하는 유전자의 돌연변이가 원발성 선천성 심장 전도장애의 원인으로 밝혀지고 있다. 사람의 부정맥 발생에 관련된 발병기전에 커다란 진보가 이루어지고 있음에도 불구하고, 개의 경우, 저먼 세퍼드의 급사 증후군 (sudden death syndrome)을 제외한 다른 전도 장애에 대한 연구는 극히 미비한 상태이다. 본 종설에서는 지금까지 밝혀진 심장 부정맥 발생의 분자 유전학적 고찰과 이와 관련된 사람의 유전학적 질환들과 이와 유사한 개의 선천성 심장 전도 장애에 대해 연구 고찰하였다.

ESR Analysis of Cupric Ion Species Exchanged into NaH-ZSM-5 Gallosilicate

  • Yu, Jong-Sung;Kim, Jeong-Yeon
    • 한국자기공명학회논문지
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    • 제5권1호
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    • pp.1-12
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    • 2001
  • ZSM-5 gallosilicate molecular sieves was synthesized and cupric ion was ion-exchanged into the gallosilicate. The locations of Cu(ll) species in the framework and their interactions with various adsorbates were characterized by combined electron spin resonance(ESR) and electron spin echo modulation(ESEM) methods. It was found that in a fresh hydrated material, Cu(II) is octahedrally coordinated to six water molecules. This species is located in the channel intersections of two sinusoidal channels and rotates rapidly at room temperature. Evacuation removes some of these water molecules, leaving the Cu(II) coordinated to less water molecules and anchored to of oxygens in the channel wall. Dehydration produces two Cu(II) species, both of which are located in sites inaccessible to oxygen as evidenced by non-broadening of its ESR lines by oxygen. Adsorption of adsorbate molecules such as water, alcohols, ammonia, acetonitrile and ethylene on dehydrated CuNaH-ZSM-5 gallosilicate materials causes changes in the ESR spectrum of Cu(II), indicating the migration of Cu(II) into main channels to form complexes with these adsorbates there. Cu(II) forms a complex with two molecules of methanol, ethanol and propanol, respectively as evidenced by ESR parameters and ESEM data. Cu(II) also forms a square planar complex with four molecules of ammonia, based on the resolved nitrogen superhyperfine interactions and their ESEM parameters. Cu(II) forms a complex with two molecules of acetonitrile based on the ESR parameters and ESEM data. Interestingly, however, only part of Cu(II) interacts indirectly with one molecule of nonpolar ethylene based on ESR and ESEM analyses.

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Ginsentology II: Chemical Structure-Biological Activity Relationship of Ginsenoside

  • Lee, Byung-Hwan;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • 제31권2호
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    • pp.69-73
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    • 2007
  • Since chemical structures of ginsenoside as active ingredient of Panax ginseng are known, accumulating evidence have shown that ginsenoside is one of bio-active ligands through the diverse physiological and pharmacological evaluations. Chemical structures of ginsenoside could be divided into three parts depending on diol or triol ginsenoside: Steroid- or cholesterol-like backbone structure, carbohydrate portions, which are attached at the carbon-3, -6 or -20, and aliphatic side chain coupled to the backbone structure at the carbon-20. Ginsenosides also exist as stereoisomer at the carbon-20. Bioactive ligands usually exhibit the their structure-function relationships. In ginsenosides, there is little known about the relationship of chemical structure and biological activity. Recent reports have shown that ginsenoside $Rg_3$, one of active ginsenosides, exhibits its differential physiological or pharmacological actions depending on its chemical structure. This review will show how ginsenoside $Rg_3$, as a model compound, is functionally coupled to voltage-gated ion channel or ligand-gated ion channel regulations in related with its chemical structure.

전단응력에 의한 골육종 세포의 칼슘이온 시응답 특성 측정 (Measurement of Time response of Calcium Ion in MG-63 Cells Induced by Shear Stress)

  • 박소희;신정욱;정옥찬
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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    • pp.183-183
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    • 2008
  • This paper presents the time responses of calcium ($Ca^{2+}$) ion concentration of MG-63 cells induced by a constant shear stress in micro channel were observed in the real time. Most of cells have similar rising time. There were some time delays because of the initial position of the cell in the micro channel along the pressure-driven fluid flow. The concentration of $Ca^{2+}$ exponentially decreased while time constant of each profile did not have any relation to the peak value of concentration.

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$K^{+}$ 이온교환 도파로형 광결합기의 모델링 및 특성 (Modeling and Characteristics of $K^{+}$ Ion-exchanged Waveguide-type Optical Coupler)

  • 천석표;박태성;정홍배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1995년도 추계학술대회 논문집
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    • pp.194-197
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    • 1995
  • In this study, we performed a modeling for $K^{+}$ ion-exchanged diffused channel waveguide and waveguide-type optical coupler by WKB(Wentzel-Kramer-Brillouim) dispersion equation, field distribution equation of mode and coupled mode theory, and examined the optical-power-dividing of the optical coupler fabricated by using the modeling condition. The optical-power-dividing was observed at the waveguide-type optical coupler with 3[$\mu\textrm{m}$] line-width, 6[$\mu\textrm{m}$] space between channel waveguides, and 3[mm] interaction length.

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Cloning of a novel ion channel candidate by in silico gene mining

  • Shim, Won-Sik;Kim, Man-Su;Yang, Young-Duk;Park, Seung-Pyo;Kim, Byung-Moon;Oh, Uh-Taek
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.192.2-193
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    • 2003
  • Capsaicin, a pungent ingredient in chili pepper, is known to excite sensory neurons that mediate pain sensation. This effect of capsaicin is determined by unique receptors and the capsaicin receptor (transient receptor potential subfamily V, member 1 (TRPV1)) was cloned recently. TRPV1 contains six transmembrane domains and three ankyrin repeats at N-terminal. This characteristic architecture is common in other ion channel in TRPV families. (omitted)

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다결정 실리콘 박막 트랜지스터 제조공정 기술 (Polycrystalline Silicon Thin Film Transistor Fabrication Technology)

  • 이현우;전하응;우상호;김종철;박현섭;오계환
    • 한국진공학회지
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    • 제1권1호
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    • pp.212-222
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    • 1992
  • To use polycrystalline Si Thin Film Transistor (poly-Si TFT) in high density SRAM instead of High Load Resistor (HLR), TFT is needed to show good electrical characteristics such as large carrier mobility, low leakage current, high driver current and low subthreshold swing. To satisfy these electrical characteristics, the trap state density must be reduced in the channel poly. Technological issues pertinent to the channel poly fabrication process are investigated and discussed. They are solid phase growth (SPG), Si-ion implantation, laser annealing and hydrogenation. The electrical properties of several CVD oxides used as the gate oxide of TFT are compared. The dependence of the electrical characteristics of TFT on source-drain ion-implantation dose, drain offset length and dopant lateral diffusion are also described.

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