• 제목/요약/키워드: attached single cell

검색결과 37건 처리시간 0.031초

Electricity Generation from MFCs Using Differently Grown Anode-Attached Bacteria

  • Nam, Joo-Youn;Kim, Hyun-Woo;Lim, Kyeong-Ho;Shin, Hang-Sik
    • Environmental Engineering Research
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    • 제15권2호
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    • pp.71-78
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    • 2010
  • To understand the effects of acclimation schemes on the formation of anode biofilms, different electrical performances are characterized in this study, with the roles of suspended and attached bacteria in single-chamber microbial fuel cells (MFCs). The results show that the generation of current in single-chamber MFCs is significantly affected by the development of a biofilm matrix on the anode surface containing abundant immobilized microorganisms. The long-term operation with suspended microorganisms was demonstrated to form a dense biofilm matrix that was able to reduce the activation loss in MFCs. Also, a Pt-coated anode was not favorable for the initial or long-term bacterial attachment due to its high hydrophobicity (contact angle = $124^{\circ}$), which promotes easy detachment of the biofilm from the anode surface. Maximum power ($655.0\;mW/m^2$) was obtained at a current density of $3,358.8\;mA/m^2$ in the MFCs with longer acclimation periods. It was found that a dense biofilm was able to enhance the charge transfer rates due to the complex development of a biofilm matrix anchoring the electrochemically active microorganisms together on the anode surface. Among the major components of the extracellular polymeric substance, carbohydrates ($85.7\;mg/m^2_{anode}$) and proteins ($81.0\;mg/m^2_{anode}$) in the dense anode biofilm accounted for 17 and 19%, respectively, which are greater than those in the sparse anode biofilm.

G292 세포에서 $K^+$통로에 대한 phorbol ester의 효과 (Effect of Phorbol ester on $K^+$channel in an G292 osteoblast-like cell)

  • 김미경;박수병
    • 대한치과교정학회지
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    • 제32권3호
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    • pp.227-234
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    • 2002
  • 본 연구는 조골세포의 특성을 가지고 있는 G292세포주를 이용하여 세포막 이온통로에 대한phorbol ester의 효과를 조사하여 protein kinase C (PCK)의 이온통로에 대한 작용기전을 밝히고자 하였다. Patch clamp 기법을 이용하여 G292 세포에서 cell-attached configuration으로 단일이온통로의 활동을 관찰하고 Phorbol 12, 13-dibutyrate (PDBu)의 효과를 관찰하였다. 안정상태 G292 세포에서 cell-attached 모드로 세포막의 단일이 온통로 활동을 관찰한 결과 45pS의 $K^+$통로가 특징 적으로 우세하였다. 유리 전극 내부에 세포내 액과 세포외 액을 사용하여 전류-전압의 관계를 조사한 결과, 세포내 액을 사용하는 경우에는 역전전압이 5.5mV이었으며 세포외액을 사용하는 경우에는 -27mV이었다. PDBu는 45pS의 이온통로를 10nM이상의 농도에서 이온통로의 열릴 확률을 증가시켰으며 PKC억제제인 staurosporine 10nM에 의하여 차단되는 특성을 보였다. PDBu는 45pS의 이온통로에 작용하여 전류-전압의 관계에서 역전전압을 음의 방향으로 이동시켰으며 동일한 막전압에서 단일이온통로의 전류 크기를 증가시켰다. G292세포에서 PDBu에 의하여 PKC가 활성화되는 것을 western blot으로 확인한 결과 PDBu 0.luM은 세포질에서 세포막으로 PKC translocation을 유의하게 증가시키는 것을 확인하였다. 이상의 결과는 G292세포에서 phorbol ester의 일종인 PDBu가 세포내 PKC를 활성화시켜 45pS의 이온통로를 활성화시키며 이러한 작용의 결과로 세포막전압의 변화가 세포의 기능을 조절할 것으로 사료된다.

인간 신장세포로부터 scu-PA의 경제적 생산을 위한 무혈청 배지의 개발 (The Development of Serum Free Medium for the Economic Production of scu-PA from HEK Cells)

  • 김현규;김현구
    • KSBB Journal
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    • 제9권5호
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    • pp.518-524
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    • 1994
  • Cytodex III 마립담체를 이용하여 무혈청배지에서 인간선장 세포를 배양하였다. 무혈청애지에서 미립담체 표변에 세포들은 정상적으로 부착하고 확 산하면셔 세포들은 담체에서 담체로 이동하여 생육 하였다. 미립담체에 접착 수율은 1%의 혈청 을 포 함된 배지에서는 약 93%인 반면에 무혈청배지에 서는 85% 정도로 나타났다. 접착된 세포의 90% 이상이 유가식 및 연속배양에서 탐체의 표변에 접 착한 후 6시간 후에 확산하며 생육하였다. 유가식 배양에셔 서1포농도와 최대 scu-P A 농도는 각각 $9.1{\times}10^5$ cells/m!와 1790 IU/ml이였고 연속배양에 셔는 각각 $2.5{\times}10^6$ cells/m]와 1820 IU/ml로 나타났다. 또한 저혈청배지에셔는 scu-P A가 tc-P A로의 전환율이 10% 정도로 높은데 비교하여 무혈 청배지에서는 전환율이 4.8%로 낮은 것으로 나타났 다. 이처럼 무혈청배지는 저혈청배지에셔보다 낮은 tc-P A로의 전환율을 유지할 수 있는 이점이 었다.

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Modulation of $Ca^{2+}-Activated$ Potassium Channels by cGMP-Dependent Signal Transduction Mechanism in Cerebral Arterial Smooth Muscle Cell of the Rabbit

  • Han, Jin;Kim, Na-Ri;Lee, Kwang-Bok;Kim, Eui-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권6호
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    • pp.445-453
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    • 2000
  • The present investigation tested the hypothesis that the activation of protein kinase G (PKG) leads to a phosphorylation of $Ca^{2+}-activated$ potassium channel $(K_{Ca}\;channel)$ and is involved in the activation of $K_{Ca}$ channel activity in cerebral arterial smooth muscle cells of the rabbit. Single-channel currents were recorded in cell-attached and inside-out patch configurations of patch-clamp techniques. Both molsidomine derivative 3-morpholinosydnonimine-N-ethylcarbamide $(SIN-1,\;50\;{\mu}M)$ and 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate $(8-pCPT-cGMP,\;100\;{\mu}M),$ a membrane-permeable analogue of cGMP, increased the $K_{Ca}$ channel activity in the cell-attached patch configuration, and the effect was removed upon washout of the drugs. In inside-out patches, single-channel current amplitude was not changed by SIN-1 and 8-pCPT-cGMP. Application of ATP $(100\;{\mu}M),$ cGMP $(100\;{\mu}M),$ ATP+cGMP $(100\;{\mu}M\;each),$ PKG $(5\;U/{\mu}l),$ ATP $(100\;{\mu}M)+PKG\;(5\;U/{\mu}l),$ or cGMP $(100\;{\mu}M)+PKG\;(5\;U/{\mu}l)$ did not increase the channel activity. ATP $(100\;{\mu}M)+cGMP\;(100\;{\mu}M)+PKG\;(5\;U/{\mu}l)$ added directly to the intracellular phase of inside-out patches increased the channel activity with no changes in the conductance. The heat-inactivated PKG had no effect on the channel activity, and the effect of PKG was inhibited by 8-(4-Chlorophenylthio)-guanosine-3',5'-cyclic monophosphate, Rp-isomer $(Rp-pCPT-cGMP,\;100\;{\mu}M),$ a potent inhibitor of PKG or protein phosphatase 2A (PP2A, 1 U/ml). In the presence of okadaic acid (OA, 5 nM), PP2A had no effect on the channel activity. The $K_{Ca}$ channel activity spontaneously decayed to the control level upon washout of ATP, cGMP and PKG, and this was prevented by OA (5 nM) in the medium. These results suggest that the PKG-mediated phosphorylations of $K_{Ca}$ channels, or some associated proteins in the membrane patch increase the activity of the $K_{Ca}$ channel, and the activation may be associated with the vasodilating action.

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STUDIES ON THE TISSUE CULTURE OF PANAX GINSENG

  • Harn C
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1974년도 학술대회지
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    • pp.9-22
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    • 1974
  • Unlike the tissue culture in animals and human being, in higher plants various parts of the plant are cultured for varied purposes, and they are named variously depending on which parts are used as explants or what purposes they are cultured for. Followings are some of the names of culture used frequently: organ culture, tissue culture, callus culture, single cell culture, meristem culture, mericlone culture, ovary culture, ovule culture, embryo culture, endosperm culture, anther culture, pollen culture, protoplast culture, etc.. As the names of the culture indicate, in some kinds of culture the explants used for culture are actually not tissues, but organs, single cells, or protoplasts. It seems, however, convenient to call all of the above-mentioned cultures grossly as tissue culture. Several kinds of tissue culture were attempted using Panax ginseng as material and some of the results were summarized below. 1. Callus culture After dormancy of the sed was broken, whole embryo or parts (hypocotyl, cotyledon and epicotyl) of partly grown embryo were cultured in the media supplemented with growth regulators. Rapid swelling occurred in a few weeks, but most of the swelling was observed only in the basal part of epicotyl, changes in the other parts of embryo appearing in much later stages. The swelling or increase in size, however, was resulted not from the divisions of cells, but from the mere expansion of cell. Real calli were formed about two months after inoculation of explants. Callus tissues developed from cortex, pith, and vascular bundle in the cases of hypo- and epicotyl, from mesophyl tissue in the case of cotyledon. Shoots developed more easily from cotyledons regardless of whether they are detached from or attached to the embryo proper. 2. Culture in the Knudson C medium When cotyledons, detached from or attached to the embryo proper, were cultured in the growth regulator-free Knudson C medium comprision only several kinds of mineral compounds and sucrose, shoot primordium or callus developed profusely and finally plantlets were produced directly from shoot primordium or indirectly through callus. In this medium epidermal cells as well as mesophyl cells of the cotyledon became meristematic and divided, changing into multinucleate cells or multicellular bodies, developing eventually into either shoot primordia or calli. 3. Anther culture Anthers were cultured in the media supplemented with various growth regulators applied singly or in combinations. Callus was formed mostly in the connective tissue of anther. Cells of anther wall layers changed in appearance, but no division occurred. Microspores of all stages in development were not changed, ruling out the possibility that microspore-originated callus might be formed. 4. Isolation of protoplast Protoplasts were isolated from young root, leaf, and epicotyl, using 0.7M D-mannitols as osmoticum and using macerozyme and cellulase respectively for maceration and digestion of the cell wall. Production in large number of naked intact protoplast was rather difficult as compared with other plant species. Fusion of protoplasts occurred infrequently mainly due to the fewer number of naked protoplasts in the solution.

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Polypropylene Bundle Attached Multilayered Stigeoclonium Biofilms Cultivated in Untreated Sewage Generate High Biomass and Lipid Productivity

  • Kim, Byung-Hyuk;Kim, Dong-Ho;Choi, Jung-Woon;Kang, Zion;Cho, Dae-Hyun;Kim, Ji-Young;Oh, Hee-Mock;Kim, Hee-Sik
    • Journal of Microbiology and Biotechnology
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    • 제25권9호
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    • pp.1547-1554
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    • 2015
  • The potential of microalgae biofuel has not been realized because of the low productivity and high costs associated with the current cultivation systems. In this study, a new low-cost and transparent attachment material was tested for cultivation of a filamentous algal strain, Stigeoclonium sp., isolated from wastewater. Initially, the different materials tested for Stigeoclonium cultivation in untreated wastewater were nylon mesh, polyethylene mesh, polypropylene bundle (PB), polycarbonate plate, and viscose rayon. Among the materials tested, PB led to a firm attachment, high biomass (53.22 g/m2, dry cell weight), and total lipid yield (5.8 g/m2) with no perceivable change in FAME profile. The Stigeoclonium-dominated biofilm consisted of bacteria and extracellular polysaccharide, which helped in biofilm formation and for effective wastewater treatment (viz., removal efficiency of total nitrogen and total phosphorus corresponded to ~38% and ~90%, respectively). PB also demonstrated high yields under multilayered cultivation in a single reactor treating wastewater. Hence, this system has several advantages over traditional suspended and attached systems, with possibility of increasing areal productivity three times using Stigeoclonium sp. Therefore, multilayered attached growth algal cultivation systems seem to be the future cultivation model for large-scale biodiesel production and wastewater treatment.

The Effects of Intracellular Monocarboxylates on the ATP-sensitive Potassium Channels in Rabbit Ventricular Myocytes

  • Kim, Na-Ri;Han, Jin;Kim, Eui-Yong;Ho, Won-Kyung;Earm, Yung E.
    • The Korean Journal of Physiology and Pharmacology
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    • 제2권5호
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    • pp.581-589
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    • 1998
  • A regulating mechanism of the ATP-sensitive potassium channels $(K_{ATP}\;channels)$ is yet to fully explained. This study was carried out to investigate the effects of intracellular application of monocarboxylates (acetate, formate, lactate, and pyruvate) on $K_{ATP}$ channels in isolated rabbit ventricular myocytes. Single channel currents of $K_{ATP}$ channels were recorded using the excised inside-out or permeabilized attached (open-cell) patch-clamp technique at room temperature. Intracellular application of acetate, formate and pyruvate led to an inhibition of channel activity, whereas intracellular application of lactate increased channel activity. These effects were reversible upon washout. Analysis of single channel kinetics showed that monocarboxylates did not affect open-time constant and close-time constant. These results suggest that monocarboxylates participate in modulating $K_{ATP}$ channels activity in cardiac cells and that modulation of $K_{ATP}$ channels activity may resolve the discrepancy between the low $K_i$ in excised membrane patches and high levels of intracellular ATP concentration during myocardial ischemia or hypoxia.

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Parthenogenetic Activation of Porcine Oocytes and Isolation of Embryonic Stem Cells-like Derived from Parthenogenetic Blastocysts

  • Xu, X.M.;Hua, J.L.;Jia, W.W.;Huang, W.;Yang, C.R.;Dou, Z.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • 제20권10호
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    • pp.1510-1516
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    • 2007
  • These experiments were carried out to optimize the parameters of electrical activation, methods of parthenogenetic activation and embryo culture in vitro and meanwhile to isolate embryonic stem cells-like (ESCs) derived from porcine parthenogenetic blastocysts (pPBs). These results showed that, as the electric field strength increased from 1.0 to 2.7 kV/cm, the cleavage rate of parthenogenetic embryos increased gradually but the rate of oocyte lysis was significantly increased when using 2.7 kV/cm field strength. The rate of cleavage in 2.2 and 2.7 kV/cm groups was significantly increased in comparison with that of the 1.0 kV/cm group. A voltage field strength of 2.2 kV/cm DC was used to investigate blastocyst development following activation with a single pulse of 30 or $60-{\mu}sec$ pulse duration. The optimum pulse duration was 30-${\mu}sec$, with a blastocyst rate of 20.7%. Multiple pulses were inferior to a single pulse for blastocyst yield (8.0% vs. 29.9) (p<0.05). For porcine oocyte parthenogenetic activation methods, the rates of cleavage (79.0% vs. 59.8%) and blastocysts (19.4% vs. 3.4%) were significantly increased in electrical activation in contrast to chemical activation with ionomycin/6-DMAP (p<0.05). Rates of cleavage and blastocyst formation in NCSU-23 and PZM-3 embryo media were higher than those of G1.3/G2.3 serial culture media, but there was no significant difference among the three groups. The total cell number of blastocysts in PZM-3 embryo culture media containing $5{\mu}g/ml$ insulin was significantly higher than that of the control (no insulin) ($44.3{\pm}9.1$ vs. $33.9{\pm}11.7$). For isolation of PESCs-like, the rates of porcine blastocysts attached to feeder layers and ICM colony formation in Method B (nude embryo culture) were better than those in Method A (intact embryo culture).

Bile Acid Inhibition of N-type Calcium Channel Currents from Sympathetic Ganglion Neurons

  • Lee, Hye-Kyung;Lee, Kyoung-Hwa;Cho, Eui-Sic
    • The Korean Journal of Physiology and Pharmacology
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    • 제16권1호
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    • pp.25-30
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    • 2012
  • Under some pathological conditions as bile flow obstruction or liver diseases with the enterohepatic circulation being disrupted, regurgitation of bile acids into the systemic circulation occurs and the plasma level of bile acids increases. Bile acids in circulation may affect the nervous system. We examined this possibility by studying the effects of bile acids on gating of neuronal (N)-type $Ca^{2+}$ channel that is essential for neurotransmitter release at synapses of the peripheral and central nervous system. N-type $Ca^{2+}$ channel currents were recorded from bullfrog sympathetic neuron under a cell-attached mode using 100 mM $Ba^{2+}$ as a charge carrier. Cholic acid (CA, $10^{-6}M$) that is relatively hydrophilic thus less cytotoxic was included in the pipette solution. CA suppressed the open probability of N-type $Ca^{2+}$ channel, which appeared to be due to an increase in (no activity) sweeps. For example, the proportion of sweep in the presence of CA was ~40% at +40 mV as compared with ~8% in the control recorded without CA. Other single channel properties including slope conductance, single channel current amplitude, open and shut times were not significantly affected by CA being present. The results suggest that CA could modulate N-type $Ca^{2+}$ channel gating at a concentration as low as $10^{-6}M$. Bile acids have been shown to activate nonselective cation conductance and depolarize the cell membrane. Under pathological conditions with increased circulating bile acids, CA suppression of N-type $Ca^{2+}$ channel function may be beneficial against overexcitation of the synapses.

염전 병행 태양광 발전 시스템 타당성 검토를 위한 기초연구 (Feasibility Study of Salt Farm and Solar Power Paraell System)

  • 강성현;김봉석;김근호;박종성;김덕성;임철현
    • Current Photovoltaic Research
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    • 제9권1호
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    • pp.17-21
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    • 2021
  • In this study, the effect of water level and temperature on the power generation was investigated in a water tank with an aquavoltaic PV module to perform feasibility research for the development of salt farm aquavoltaic system. The silicon solar cell attached to the bottom of each water tank is a 1-cell mini module, and the underwater effects of the crystal phase (19.0~19.9% of single- & 17.9~19.9% of poly-crystalline) of the PV module were investigated, and power generation characteristics for water level (0~10 cm) and temperature (10~40℃) were analyzed. The deterioration coefficients according to the water level and temperature of each single- and poly-crystalline module were investigated at very similar levels such as, -2.01 %/cm and -2.02 %/cm, -0.50 %/℃ and -0.48 %/℃, respectively. Therefore, in salt farm aquavoltaic system, water levels need to maintain as low as possible, and heat-induced degradation is similar to those shown in general land, and no factors have been found to be affected by the underwater environment depending on the determination.