• Title, Summary, Keyword: Transport

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Changes on the Methylmercury-induced Cytotoxicity by Control of Cell Membrane Transport System (세포막 물질수송계의 조절에 의한 유기수은의 세포독성 변화에 대한 연구)

  • 염정호;고대하;김준연;김남송
    • Journal of Environmental Health Sciences
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    • v.26 no.4
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    • pp.88-96
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    • 2000
  • The aim of the current study was to evaluate the transport system in EMT-6 cell for the uptake of the methylmercury(MeHg). Several inhibitors ere used to test used to test which potential transport system might be involoved in MeHg uptake. Probenecid was used to test the organic transport system, valinomycin for testing the effect of the membrane potential, cytochalasin B for testing the facilitated diffusive D-glucose transport system and colchicine for testing the microtubule system. Ouabain for evaluating active transport system, 4',4-diisothiocyano-2',2-stilbenedisulfonic acid(DIDS) the Cl- ion transport system and verapamil for the $Ca^{2+}$ transprot system. Significantly, MeHg decreased the synthesis of nitric oxcide(NO) and intracellular ATP in ENT-6 cells. In the condition of ouabain containing with MeHg decreased the production of NO and intracelluar ATP. In the treatment of inhibitors, ouabain showed protective effect against cytotoxicity of MeHg but ather inhibitors not showed protective effects. The protective effects of ouabain against the cytotoxicity of MeHg deoended on the concentration of added ouabain to the culture medium for MET-6 cells. These result showed that the uptake of MeHg might be involved in the active transport system. Active transports system seems to share similarities with the transport systems for the uptake of MeHg when using MeHg and MeHg-glutathione complex.x.

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Evaluation of Bacterial Transport Models for Saturated Column Experiments

  • Ham, Young-Ju;Kim, Song-Bae;Kim, Min-Kyu;Park, Seong-Jik
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.7
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    • pp.55-63
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    • 2006
  • Bacterial transport models were evaluated in this study to determine the suitable model at describing bacterial transport in saturated column experiments. Four models used in the evaluation were: advective-dispersive equation (ADE) + equilibrium sorption/retardation (ER) + kinetic reversible sorption (KR) (Model I), ADE + two-site sorption (Model 2), ADE + ER + kinetic irreversible sorption (KI) (Model 3), ADE + KR + KI (Model 4). Firstly, analyses were performed with the first experimental data, showing that Model 4 is appropriate for describing bacterial transport. Even if Model 1 and 2 fit well to the observed data, they have a defect of not including the irreversible sorption, which is directly related to mass loss of bacteria. Model 3 can not properly describe the tailing observed in the data. However, further analysis with the second data indicates that Model 4 can not describe retardation of bacteria, even if the sorption-related parameters are varied. Therefore, Model 4 is modified by incorporating retardation factor into the model, resulting in the improved fitting to the data. It indicates that the transport model, into which retardation, kinetic reversible sorption, and kinetic irreversible sorption are incorporated, is suitable at describing bacterial transport in saturated column experiments. It is expected that the selected transport model could be applied to properly analyze the bacterial transport in saturated porous media.

A study on the Exchange of goods transport freight by the Inter-Korean Railway Connection (남북철도 연결에 따른 화물운송에 대한 연구)

  • Park Hong-Soon
    • Proceedings of the KSR Conference
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    • pp.190-195
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    • 2003
  • This thesis watches for the present condition of both economic exchange and goods transport between South and North Korea focused on material side as a provision for the railway connection between them. This is also a predicting thesis for a smooth goods transport in case of setting up a goords transport system between south and North Korea predicting transport demand for the connection of a railway and road studying fundamental facilities and transport related laws.

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Implementation of RTP based Image Transport System using JPEG2000 (RTP 기반의 JPEG2000 영상 전송 시스템 구현)

  • 박동진;정영기
    • Proceedings of the IEEK Conference
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    • pp.355-358
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    • 2002
  • In this paper, we propose RTP(Real-Time Transport Protocol) based image transport system to transport still images in real-time after JPEG2000 compression, which is still image compression standard for next generation. To add RTP packet on UDP packet, the image transport system inserts packetizer and depacketizer process into transmitter and receiver of RTP data, respectively. We apply the proposed system to several image and compare the transport time to TCP-based method.

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Effect of Polyamine on Auxin Polar Transport in Corn Coleoptile Segments (Polyamine이 옥수수 자엽초 절편에서 오옥신 이동에 미치는 영향)

  • 허윤정
    • Journal of Plant Biology
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    • v.34 no.4
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    • pp.297-302
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    • 1991
  • The effects of polyamines on auxin polar transport were studied in corn coleoptile segments. Among putresine, spermidine and spermine tested in labelled auxin transport, spermidine inhibited auxin polar transport most strongly. Its inhibitory effect appeared after 1 h of transport period. Spermidine inhibited labelled auxin and 14C-benzoic acid accumulation into the tissue in the various pH range tested (pH 4.0-8.0). These results suggest that the inhibition of auxin transport may not be due to decrease in pH by spermine the effect of decreased pH in the extracellular space.

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Innovations as an Option to Increase the Market Share of Rail Freight Transport in Europe

  • Wiegmans, Bart W.
    • International Journal of Railway
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    • v.2 no.2
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    • pp.80-92
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    • 2009
  • Successful market adoption of rail freight transport innovations that might offer opportunities for market share increase is the focus of this paper. Firstly, seen from a theoretical point of view, it is not incremental innovations but radical organizational and transformation innovations that are likely to increase the market share of rail freight transport. Secondly, the particular inovations that offer some success potential for market adoption are: dedicated infrastructure, the fixed timetable, locomotive upgrades, and INTERFACE. Thirdly, unfortunately, the opportunities to increase the market share of rail freight transport appear to be limited.

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A study on the exchange Kaesong area of goods transport train by the inter-Korean Railway Connection (남북철도 연결에 따른 개성지역 화물열차운행에 대한 연구)

  • Park Hong-Soon
    • Proceedings of the KSR Conference
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    • pp.1671-1676
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    • 2004
  • This thesis watches for the present condition of both economic exchange and goods transport between South and North Korea focused on material side as a provision for the railway connection between them. This is also a predicting thesis for a smooth goods transport in case of setting up a goods transport system between south and North Korea predicting transport demand for the connection of a railway and road studying fundamental facilities and transport related laws.

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Transport Coefficients across Charged Mosaic Membrane

  • Yang, Wong-Kang
    • Bulletin of the Korean Chemical Society
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    • v.25 no.5
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    • pp.665-667
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    • 2004
  • In previous studies, charged mosaic membranes having two different fixed charges in the membrane matrix indicated unique transport behavior such as preferential material transport. In this study, the composite charged mosaic membrane endurable to mechanical pressure in practical application was investigated from the same aspect of solute and solvent transport as before. Lp and ${\omega}$ estimated by taking account of active layer thickness were satisfactorily consistent with those in mosaic membrane without reinforcement. On the other hand, the reflection coefficient s indicated the negative value that suggests preferential material transport.

Measuring stress responses using active biotelemetry in cattle II. Fluid administration for reducing transport stress (Active biotelemetry를 이용한 젖소의 스트레스 반응 측정: II. 수송 스트레스 감소를 위한 수액투여 효과)

  • Lee, Su-han;Lee, Byeong-han;Lim, Joa-jin;Kim, Jin-young;Lee, Dong-hee;Kim, Jae-kyung;Choe, Nong-hoon;Jeong, Soon-wuk;Chung, Byung-hyun
    • Korean Journal of Veterinary Research
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    • v.41 no.4
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    • pp.603-609
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    • 2001
  • A transport stress is one of the main causes of economic losses and physiological dysfunction. The present study has been performed to suggest a method to decrease the adverse effects above mentioned from transport. The groups were prepared as follows; (1) Control group : 4 cattle transported for 5 hrs (274 km) without any treatment, (2) Treatment group : 4 cattle treated with electrolyte-mineral solution (I.V.) at 1 hr before the enrollment of transport under same experimental condition with Control group. The blood specimens were collected at 1 hr before transport, 2.3 hrs (135 km) and 5 hrs (274 km) after the enrollment of transport, and 1, 6 and 18 hrs after fulfillment of transport. The collected blood specimens were analyzed for cortisol and epinephrine. Core temperature and heart rate were measured with active biotelemetry in every 30 minutes from 0.5 hr before the start of transport to 18 hrs after the end of transport. In results, the level of cortisol considerably increased to the peak either in Control group ($5.3{\pm}1.3{\mu}g/d{\ell}$) and in Treatment group ($4.0{\pm}2.6{\mu}g/d{\ell}$) at 2.3 hrs in transport. The concentration of epinephrine of Treatment group had been higher than that of Control group from the start of transport to 18 hrs after the fulfillment of transport. Particularly there was the biggest gap between Control and Treatment groups, $424.0{\pm}194.1pg/m{\ell}$ and $209.1{\pm}65.1pg/m{\ell}$ respectively, at 6 hrs after the end of transport. The heart rates were considerably increased either in Control group ($81.5{\pm}18.5$ to $126.3{\pm}7.8beats/min$) and in Treatment group ($114.3{\pm}14.4$ to $140.8{\pm}22.4beats/min$) with the enrollment of transport. These results indicate that the concentration of cortisol and the heart rate were pertinent to cognitive parameters to evaluate physiological responses against stress such as transport. In addition, the intravenous administration of electrolyte-mineral solution could be suggested as the method to decrease the adverse effects from a transport stress.

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Olefin/Paraffin Separation though Facilitated Transport Membranes in Solid State

  • Hong, Seong-Uk;Won, Jong-Ok;Hong, Jae-Min;Park, Hyun-Chae;Kang, Yong-Soo
    • Proceedings of the Membrane Society of Korea Conference
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    • pp.15-18
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    • 1999
  • A simple mathematical model for facilitated mass transport through a fixed site carrier membrane was derived by assuming an instantaneous, microscopic concentration (activity) fluctuation. The current model demonstrates that the facilitation factor depends on the extent of concentration fluctuation, the time scale ratios of diffusion to chemical reaction and the ratio of the carrier concentration to the solute solubility in matrix. The model was examined against the experimental data on oxygen transport in membranes containing metallo-porphyrin carriers, and the agreement was exceptional (within 10% error). The basic concept of this approach was applied to separate olefin from olefin/paraffin mixtures. A proprietaty carrier, developed here, resulted that the selectivity of propylene over propane was more than 120 and the propylene permeance exceed 40 gpu.

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