• 제목/요약/키워드: Ion channels

검색결과 258건 처리시간 0.024초

T헝 마이크로채널 연결부 압력구동 유동의 PIV계측 (PIV Measurements of the Pressure Driven Flow Inside a T-Shaped Microchannel Junction)

  • 최제호;이인섭
    • 한국가시화정보학회지
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    • 제1권1호
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    • pp.75-81
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    • 2003
  • A custom micro-PIV optics assembly has been used to measure the flow fold inside a T-junction of a microchannel. The micro-PIV system consists of microscope objectives of various magnifications, a dichroic cube, and an 8-bit CCD camera. Fluorescent particles of diameters 620 nm have been used with a Nd:YAG laser and color filters. A programmable syringe pump with Teflon tubings were used to inject particle-seeded distilled water into the channel at flow rates of 2.0, 4.0, 6.0 mL/hr. The micro-channels are fabricated with PDMS with a silicon mold, then O$_{2}$ -ion bonded onto a slide glass. Results show differences in flow characteristics and resolution according to fluid injection rates, and magnifications, respectively. The results include PIV data with vector-to-vector distances of 2 $\mu$m with 32 pixel-square interrogation windows at 50$\%$ overlap.

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SDB와 전기화학적 식각정지에 의한 블크 마이크로머신용 3차원 미세구조물 제작 (Fabrication of 3-dementional microstructures for bulk micromachining by SDB and electrochemical etch-stop)

  • 정연식;정귀상
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1890-1892
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    • 2001
  • This paper described on the fabrication of microstructures by DRIE(Deep Reactive Ion Etching). SOI(Si-on-insulator) electric devices with buried cavities are fabricated by SDB technology and electrochemical etch-stop. The cavity was fabricated the upper handling wafer by Si anisotropic etch technique. SDB process was performed to seal the fabricated cavity under vacuum condition at -750 mm Hg. In the SDB process, captured air and moisture inside of the cavities were removed by making channels towards outside. After annealing(1000$^{\circ}C$, 60 min.), the SDB SOI structure was thinned by electrochemical etch-stop. Finally, it was fabricated microstructures by DRIE as well as a accurate thickness control and a good flatness.

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폴리머 광도파로열을 이용한 파장 분할 다중화기의 제작 (Fabrication of a wavelength division multiplexer based on the polymeric arrayed-waveguide grating)

  • 오태원;이원영;신상영
    • 전자공학회논문지D
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    • 제34D권11호
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    • pp.70-75
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    • 1997
  • a wavelength division multiplexer based on a polymeric arrayed-waveguide grating has been designed and fabricated. A 4-channel multiplexer with a spacing of 3.2 nm is designe dby using te 2-dimensional beam propagation method. A UV-curable epoxy, NOA73, is used for the core layer, and a passive polymer, PMMA, for the cladding layer. The polymer waveguides are fabricated by the reactive ion etching method and their optical properties are characterized. The fabricted device has a center wavelength of 1548.3 nm, and the wavelength spacing between the channels is 3.2nm. The measured crosstalk is better than -18dB.

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Dependence of Alternating Magnetic Field Intensity on Proliferation Rate of Human Breast Cancer Cell

  • Park, Hyeji;Lee, Hyun Sook;Hwang, Do Guwn
    • Journal of Magnetics
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    • 제20권3호
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    • pp.290-294
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    • 2015
  • To investigate the effects of alternating magnetic field intensity and stimulation time on the proliferation of human breast cancer cells (BT-20), we cultured the cells under a magnetic field with a saw tooth waveform of 2 kHz. The field intensities varied from 3 to 7 mT, and the stimulation time varied from 24 to 72 hours. Cell proliferation decreased dramatically to 40% during magnetic stimulation for 72 hours at 5 mT. However, the cells were not affected by a strong magnetic field of 7 mT. The p-values obtained using statistical package for social science software were below 0.05 for 5-7 mT. This means that the results have statistical significance. However, it is difficult to explain our results based on the physiology of cell membranes, which have various ionic flows at ion channels.

분자동역학 기법을 이용한 나노튜브의 소수성 또는 친수성에 의한 내부 물 분자의 구조 연구 (Structure of Water Molecules inside Nanotubes with Varying Hydrophobicity Using Mole cular Dynamics Simulation)

  • 김대중
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.660-661
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    • 2008
  • Nanotubes fabricated with diverse materials show different hydrophobic properties. The hydrophobic property is one of key properties for possible applications to ion channels due to their affinity. This study focuses on the structures of water molecules inside nanotubes with varying hydrophobicity using molecular dynamics simulation. Hydrophobicity here is determined by varying the attraction term in Lennard-Jones potential. The number of water molecules inside hydrophilic nanotubes increase, as expected, and their mobilities also increase. This trend is rather discrete with increasing number of water molecules and this discreteness is attributed to hydrogen bond. We plan to perform energy analysis to understand these structural results.

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Photolithographic Silicon Patterns with Z-DOL (perfluoropolyether, PFPE) Coating as Tribological Surfaces for Miniaturized Devices

  • Singh, R. Arvind;Pham, Duc-Cuong;Yoon, Eui-Sung
    • KSTLE International Journal
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    • 제9권1_2호
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    • pp.10-12
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    • 2008
  • Silicon micro-patterns were fabricated on Si (100) wafers using photolithography and DRIE (Deep Reactive Ion Etching) fabrication techniques. The patterned shapes included micro-pillars and micro-channels. After the fabrication of the patterns, the patterned surfaces were chemically modified by coating Z-DOL (perfluoropolyether, PFPE) thin films. The surfaces were then evaluated for their micro-friction behavior in comparison with those of bare Si (100) flat, Z-DOL coated Si (100) flat and uncoated Si patterns. Experimental results showed that the chemically treated (Z-DOL coated) patterned surfaces exhibited the lowest values of coefficient of friction when compared to the rest of the test materials. The results indicate that a combination of both the topographical and chemical modification is very effective in reducing the friction property. Combined surface treatments such as these could be useful for tribological applications in miniaturized devices such as Micro/Nano-Electro-Mechanical-Systems (MEMS/NEMS).

천수근이 중심회백질 신경세포에서 이온통로 조절작용에 미치는 영향 (Modulation of Harpagophytum procumbens on ion channels in acutely dissociated periaqueductal gray neurons of rats)

  • 신민철;장현경;장미현;김창주;김연희;김이화
    • Korean Journal of Acupuncture
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    • 제20권4호
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    • pp.17-29
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    • 2003
  • 목적:천수근은 염증성 관절염과 염증성 장 질환 등에 사용되어왔다. 천수근이 중심회백질 신경세포에서 하행성 진통작용에 미치는 영향을 연구하였다. 방법: 중심회백질 신경세포를 분리하여 전위고정하에서 nystatin-perforated patch-clamp technique을 시행하였다. 결과: 천수근에 의하여 유발되는 이온전류는 GABA, glycine, 그리고 glutamate 수용체를 모두 활성화시켰다.

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Purinoceptor and Intracellular $Ca^{2+}$ Regulation in Rat Prostate N euronencocrine Cells

  • Kim, Jun-Hee;Nam, Joo-Hyun;Uhm, Dae-Yong;Kim, Sung-Joon
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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    • pp.45-45
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    • 2002
  • Extracellular ATP regulates a wide range of cellular function including the growth of prostate gland. Purinoceptors (ATP receptors) are divided into P2X (ligand-gated ion channels) and P2Y (G-protein-coupled receptor) subfamilies. In the present study, we investigated the types of purinoceptors in rat prostate neuroendocrine (RPNE) cells using whole-cell patch clamp technique, intracellular $Ca^{2+}$ measurement and RT-PCR analysis.(omitted)d)

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Pharmacological and medical applications of Panax ginseng and ginsenosides: a review for use in cardiovascular diseases

  • Kim, Jong-Hoon
    • Journal of Ginseng Research
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    • 제42권3호
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    • pp.264-269
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    • 2018
  • Panax ginseng, also called Asian or Korean ginseng, has long been traditionally used in Korea and China to treat various diseases. The major active ingredients of P. ginseng are ginsenosides, which have been shown to have a variety of therapeutic effects, including antioxidation, anti-inflammatory, vasorelaxation, antiallergic, antidiabetic, and anticancer. To date, approximately 40 ginsenoside components have been reported. Current research is concentrating on using a single ginseng compound, one of the ginsenosides, instead of the total ginseng compounds, to determine the mechanisms of ginseng and ginsenosides. Recent in vitro and in vivo results show that ginseng has beneficial effects on cardiac and vascular diseases through efficacy, including antioxidation, control of vasomotor function, modulation of ion channels and signal transduction, improvement of lipid profiles, adjustment of blood pressure, improvement in cardiac function, and reduction in platelet adhesion. This review aims to provide valuable information on the traditional uses of ginseng and ginsenosides, their therapeutic applications in animal models and humans, and the pharmacological action of ginseng and ginsenosides.

유아돌연사증후군과 유전성대사질환 (Sudden Infant Death Syndrome and Inborn Metabolic Disorders)

  • 윤혜란
    • 대한유전성대사질환학회지
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    • 제13권2호
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    • pp.75-80
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    • 2013
  • Specific genetic conditions may lead to sudden unexpected deaths in infancy, such as inborn errors of fatty acid oxidation and genetic disorders of cardiac ion channels. The disease may present dramatically with severe hypoketotic hypoglycemia, Reye syndrome or sudden death, typically with a peak of frequency around 3-6 month, whilst neonatal sudden death is quite rare. When undetected, approximately 20-25% of infants will die or suffer permanent neurologic impairment as a consequence of the first acute metabolic decompensation. Meanwhile, the advent of newborn screening for metabolic diseases has revealed populations of patients with disorders of fatty acid oxidation (FAO), the most frequent of which is medium chain acyl-CoA dehydrogenase (MCAD) deficiency. Without this screening, affected individuals would likely succumb to sudden infant death syndrome (SIDS). Here we describe an overview of sudden infant death syndrome and inherited metabolic disorder.

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