• Title/Summary/Keyword: dual membrane process

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Extension of the Site Binding Model for Ion Sensing Mechanism of ISFET and Its Application to the Hydrogen Ion Sensing $Si_3N_4$ Membrane (ISFET 이온감지기구의 Site Binding 모형 확장과 그 $Si_3N_4$ 수소이온 감지막에의 적용)

  • Seo, Hwa-Il;Kwon, Dae-Hyuk;Lee, Jong-Hyun;Sohn, Byung-Ki
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.11
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    • pp.1358-1366
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    • 1988
  • The dual dielectric films have been grown on single-crystalline silicon substrates with the thickness ranging from 125A to 180A at various gas and temperature conditions by using rapid thermal process that included independent nitridation step. The film characteristics and their dependence on the contents of the hydrochloric gas and the processing time have been studied. By the addition of the hydrochloric gas, the initial oxide thickness was significantly changed, but after sequential nitridation processes the thickness of the films was nevertheless a little bit varied within 10A. All the samples of the dual dielectric films show the increased breakdown voltages in proportion to the additive contents of the hydrochloric gas and also show the higher breakdown strengths than the thermal oxide and nitrided oxide films grown by the conventional furnance process or the rapid thermal nitridation process that was composed of the dependent nitridation cycles.

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The Role of $K^+$ Channels on Spontaneous Action Potential in Rat Clonal Pituitary $GH_3$ Cell Line

  • Rhim, Hye-Whon;Baek, Hye-Jung;Ho, Won-Kyung;Earm, Yung-E
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.2
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    • pp.81-90
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    • 2000
  • The types of $K^+$ channel which determine the pattern of spontaneous action potential (SAP) were investigated using whole-cell variation of patch clamp techniques under current- and voltage-clamp recording conditions in rat clonal pituitary $GH_3$ cells. Heterogeneous pattern of SAP activities was changed into more regular mode with elongation of activity duration and afterhyperpolarization by treatment of TEA (10 mM). Under this condition, exposure of the class III antiarrhythmic agent E-4031 $(5\;{\mu}M)$ to $GH_3$ cells hardly affected SAP activities. On the other hand, the main $GH_3$ stimulator thyrotropin-releasing hormone (TRH) still produced its dual effects (transient hyperpolarization and later increase in SAP frequency) in the presence of TEA. However, addition of $BaCl_2$ (2 mM) in the presence of TEA completely blocked SAP repolarization process and produced membrane depolarization in all tested cells. This effect was observed even in TEA-untreated cells and was not mimicked by higher concentration of TEA (30 mM). Also this barium-induced membrane depolarization effect was still observed after L-type $Ca^{2+}$ channel was blocked by nicardipine $(10\;{\mu}M).$ These results suggest that barium-sensitive current is important in SAP repolarization process and barium itself may have some depolarizing effect in $GH_3$ cells.

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A column study of effect of filter media on the performance of sand filter

  • Kim, Tae-hoon;Oh, Heekyong;Eom, Jungyeol;Park, ChulHwi
    • Membrane and Water Treatment
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    • v.11 no.4
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    • pp.247-255
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    • 2020
  • Sand filter is a key unit process for particle removal in water purification treatments. Its long-standing use is due to on-site customized retrofit. Proper selection of filter media is one of the retrofit approaches to improve filter performance. This study described a series of controlled laboratory column tests and examined the effects of media property on filtration and backwash. When sand media of 0.51 mm in effective size was replaced by sand of 0.60 mm, the filter run increased up to 5 times in the given bed depth. The change of media property required an increase of backwash rate by 0.05 m/min to satisfy the requirement of bed expansion, more than 20%. When the anthracite was changed with lower effective size and uniformity coefficient, correlation with sand in the filter bed could be satisfied within the permissible error between media and bulk characteristics. Besides, this selection resulted in a well-stratified configuration of media layers after bed expansion. The column study showed that the correlation of property between the dual media had a significant effect on the filter productivity and backwash interval.

Inducing Effects of Rubus coreanus on Cell Death and Apoptotic Gene Expressions in Human Breast Cancer Cells (복분자의 유방암 세포 사멸 및 사멸 유전자 발현 유도 효과)

  • Kim, Hee-Jung;Kang, Keum-Jee
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.6
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    • pp.723-732
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    • 2013
  • We investigated the inducing effects of Rubus coreanus extract (RCE) on apoptosis and its related gene expressions in human breast cancer cells. MDA-MB-231 cells were cultured in the presence of 0, 200, 300, and $400{\mu}g/mL$ RCE for 24h. MTT assay demonstrated that relative cell viability measured a decrease in a dose-dependent manner (p<0.05). This dependency was also found in the increasing levels of cell death by a dual staining with Hoechst 33322 and propidium iodide (p<0.05). These close associations was also observed by different stages of apoptotic processes, as shown by an Apoptosis Detection Kit. To determine whether the alterations in such cell activities obtained above cause the induction of apoptotic genes, PT-PCR was performed expressions of both Bcl-2 and Bax mRNAs. The Bcl-2/Bax ratio which is an important indicator of apoptosis, was found to have significantly decreased dose dependence (p<0.05). Western blot analysis also demonstrated that Caspase-3 significantly increases in a dose-dependent manner (p<0.05) in addition to similar alterations of other proteins examined. Taken these results together, the ethanolic RCE used induces a reduction in cell viability along with increased membrane permeability. This leads to a precautious apoptotic process and, subsequently, cell death through the apoptotic pathway involving Bax and Caspase-3 in human breast cancer MDA-MB-231 cells.

Targeting Analysis of Lumenal Proteins of Chloroplast of Wheat using Proteomic Techniques

  • Kamal, Abu Hena Mostafa;Kim, Da-Eun;Oh, Myoung-Won;Chung, Keun-Yook;Cho, Yong-Gu;Kim, Hong-Sig;Song, Beom-Heon;Lee, Chul-Won;Uozumi, Nobuyuki;Choi, Jong-Soon;Cho, Kun;Woo, Sun-Hee
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2010.05a
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    • pp.14-14
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    • 2010
  • Plastid proteomics are essential organelles present in virtually all cells in plants and green algae. Plastids are responsible for the synthesis and storage of key molecules required for the basic architecture and functions of plant cells. The proteome of plastid, and in particular of chloroplast, have received significant amounts of attention in recent years. Various fractionation and mass spectrometry (MS) techniques have been applied to catalogue the chloroplast proteome and its sub-organelles compartments. To better understanding the function of the lumenal sub-organelles within the thylakoid network, we have carried out a systematical analysis and identification of the lumenal proteins in the thylakoid of wheat by using Tricine-SDS-PAGE, and LTQ-ESI-FTICR mass spectrometry followed by SWISS-PROT database searching. We isolation and fractionation these membrane from fully developed wheat leaves using a combination of differential and gradient centrifugation couple to high speed ultra-centrifuge. After collecting all proteins to eliminate possible same proteins, we estimated that there are 407 different proteins including chloroplast, chloroplast stroma, lumenal, and thylakoid membrane proteins excluding 20 proteins, which were identified in nucleus, cytoplasm and mitochondria. A combination of these three programs (PSORT, TargetP, TMHMM, and TOPPRED) was found to provide a useful tool for evaluating chloroplast localization, transit peptide, transmembranes, and also could reveal possible alternative processing sites and dual targeting. Finally, we report also sub-cellular location specific protein interaction network using Cytoscape software, which provides further insight into the biochemical pathways of photosynthesis. The present work helps understanding photosynthesis process in wheat at the molecular level and provides a new overview of the biochemical machinery of the thylakoid in wheat.

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