• 한국초전도ㆍ저온공학회논문지
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• 제8권3호
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• pp.59-62
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• 2006

For electric power applications of Bi-2223/Ag superconducting tapes, a transport characteristic is important issue. A transport characteristic is strongly depends on the magnitude and direction of external time-varying magnetic field. To verify a effect of external magnetic field, we manufactured a prototype magnet and obtained transport characteristics with respect to the magnitude, the direction and the frequency of external magnetic field. The data acquired in this paper will be used as a source for the study of HTS electric power applications which is supposed to carry on.

• 한국ITS학회 논문지
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• 제6권2호
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• pp.81-94
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• 2007

날로 심각해지는 교통문제를 해결하기 위한 방안으로 첨단과학기술을 통해 정보수집, 정보처리, 정보제공 등을 수행하는 지능형교통시스템(Intelligent Transport Systems)의 중요성이 높아지고 있다. 하지만 많은 지자체 등에서 ITS 도입을 통해 교통문제를 해결하고자 하나 그에 따른 체계적인 효과분석이 부족한 실정이다. 본 연구에서는 ITS 도입에 따른 효과분석 방법론을 국내 외 사례를 참조하여 설정한 후 case study를 통한 직, 간접적인 효과분석을 목표로 하였다. 이를 통해 수원시 ITS 도입효과를 분석한 결과 통행속도는 TRC 모드로 운영시 사전에 비해 31%의 증가를 보였으며, 지체도는 43.9%로 감소하였다. 설문조사 결과에서도 ITS 시스템 운영으로 인한 개선효과가 있다고 느끼고 있었으며, 대다수가 시스템의 확장을 원하고 있었다. 경제성 분석 결과 B/C비는 5.12로 ITS사업에 대한 사업효과 및 경제적 타당성은 충분한 것으로 나타났다.

• The Korean Journal of Physiology and Pharmacology
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• 제9권2호
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• pp.125-130
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• 2005

We examined the effect of leptin on the insulin resistance in skeletal muscles by measuring the glucose transport. Male Wistar rats were fed with chow or high-fat diets for 30 days. Three days before sacrifice, high-fat fed rats were subcutaneously injected with leptin (1 mg/kg body weight) for 3 days. The glucose transports in the epitrochlearis and soleus muscle were not different among the experimental groups under basal state, however these were decreased significantly in the high fat-diet rats under insulin-stimulation (p＜0.01). Leptin treatment recovered the decreased glucose transport in the epitrochlearis (p＜0.05) and soleus (p=0.08). Triglyceride concentration in the soleus muscle was increased significantly in the high fat-fed rats, compared to chow diet rats (p＜0.01), and it was decreased significantly by leptin treatment (p＜0.01). The glucose transport was measured under basal and $60{\mu}u/ml$ of insulin with or without 50 ng/ml of leptin. Leptin had no direct stimulatory effect on glucose transport under both basal and insulin-stimulated conditions in vitro. These results demonstrate that leptin injection to high fat diet fed rats recovered impaired insulin responsiveness of the skeletal muscles and muscle triglyceride concentration. However, there was no direct stimulatory effect of leptin on insulin sensitivity of the skeletal muscle in vitro.

• The Korean Journal of Physiology and Pharmacology
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• 제13권1호
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• pp.9-14
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• 2009

We cultured canine kidney(MDCK) cells stably expressing aquaporin-2(AQP2) on collagen-coated permeable membrane filters and examined the effect of extracellular ATP on arginine vasopressin(AVP)-stimulated fluid transport and cAMP production. Exposure of cell monolayers to basolateral AVP resulted in stimulation of apical to basolateral net fluid transport driven by osmotic gradient which was formed by addition of 500 mM mannitol to basolateral bathing solution. Pre-exposure of the basolateral surface of cell monolayers to ATP(100 ${\mu}M$) for 30 min significantly inhibited the AVP-stimulated net fluid transport. In these cells, AVP-stimulated cAMP production was suppressed as well. Profile of the effects of different nucleotides suggested that the $P2Y_2$ receptor is involved in the action of ATP. ATP inhibited the effect of isoproterenol as well, but not that of forskolin to stimulate cAMP production. The inhibitory effect of ATP on AVP-stimulated fluid movement was attenuated by a protein kinase C inhibitor, calphostin C or pertussis toxin. These results suggest that prolonged activation of the P2 receptors inhibits AVP-stimulated fluid transport and cAMP responses in AQP2 transfected MDCK cells. Depressed responsiveness of the adenylyl cyclase by PKC-mediated modification of the pertussis-toxin sensitive $G_i$ protein seems to be the underlyihng mechanism.

• Journal of Acupuncture Research
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• 제18권4호
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• pp.143-151
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• 2001

Objective : This study was undertaken to determine whether Scutellaria balicalensis Georgi (SbG) extract exerts the protective effect against oxidant-induced alterations in organic cation transport in the renal proximal tubule. Methods : Organic cation transport was estimated by examining alterations in tetraethylammon - ium(TEA) uptake in rabbit renal cortical slices. The slices were treated with 0.2 mM tBHP for 60 min at $37^{\circ}C$. tBHP caused an inhibition in TEA uptake by renal cortical slices. Such an effect was accompanied by depressed Na+-K+-ATPase activity and ATP depletion. tBHP also induced a significant increase in LDH release. Results : SbG prevented tBHP-induced inhibition of TEA uptake in a dose-dependent manner at the concentration ranges of 0.05-0.1%. tBHP-induced inhibition of Na+-K+-ATPase activity and ATP depletion were significantly prevented by 0.05% SbG. tBHP-induced LDH release also was blocked by SbG. tBHP caused a significant increase in lipid peroxidation and its effect was prevented by SbG. Conclusion : These results suggest that SbG prevents oxidant-induced alterations in organic cation transport in rabbit renal cortical slices. Such protective effects of SbG may be attributed to inhibition of peroxidation of membrane lipid.

• Water Engineering Research
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• 제3권2호
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• pp.75-84
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• 2002

An Euler-Lagrange two-phase flow model is presented fur simulation sheet-flow transport under wave and current. The flow is computed by solving the Reynolds Averaged Navier-Stokes equation in conjunction with the k-$\varepsilon$ turbulence model for turbulence closure. The sediment transport is introduced as a motion of granular media under the action of unsteady flow from the Lagragian point of view. In other word, motion of every single particle is numerically traced with Movable Bed Simulator (MBS) code based on the Distinct Element Method (DEM), in which the frequent interparticle collision of the moving particles during the sheet-flow transport is sophisticatedly taken into account. The particle diameter effect on time-dependent developing process of sheet-flow transport is investigated, by using three different diameter sizes of sediment. The influence of an imposed current on oscillatory sheet-flow transport is also investigated. It is concluded that the sediment transport rate increases due to the relaxation process related to the time-lag between flow velocity and sediment motion.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.255-262
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• 2011

2010년 철도화물 수송톤수는 약 39백만 톤이며, 이 중 석탄수송은 약 6.2백만 톤으로 전체 철도수송의 약 15.7%를 차지하고 있다. 또한 철도화물 수입 중 석탄수송이 약 15.8% 수준인 517억 원으로 철도수송 품목에 있어서 수송량 및 수익에 있어서 3번째로 큰 비중을 나타내고 있다. 그러나, 철도수송에서 큰 비중을 차지하고 있는 석탄은 정부의 무연탄 감산정책과 주로 트럭운송에 의지하는 비발전용 무연탄에 대한 우선 공급으로 철도수송이 크게 감소하고 있으며, 이에 대해 석탄취급이 많은 강원권 물류 수송수익에 큰 영향을 주고 있다. 이에 따라 본 연구에서는 강원권 화물운송 중 석탄수송이 감소하는 근본적인 원인에 대해 살펴보고, 이를 해결할 수 있는 방안에 대해 살펴보았다.

• 환경위생공학
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• 제11권2호
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• pp.21-26
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• 1996

In our previous studies, we reported that lead intoxicated nerve cell by inhibition of the Na$^{+}$-K$^{+}$ ATPase activity and reduction of myo-inositol in nerve cell. As the second series of experiments, in order to understand toxic mechanism of lead for nerve cell, the characteristics of myo-inositol transport system and the effect of lead on its system have been studied in the sciatic nerves of control and lead-treated rats. A lead intoxicated animal model was induced by feeding diet containing lead to Sprague-Dawley rat for two weeks. Four weeks aged Sprague-Dawley rats were divided into three group : normal control group, 10ppm-lead treated group, 100ppm-lead treated group. All rats were sacrified at the end of two weeks. The rate o myo-inositol transport by sciatic nerve isolated from lead-treated rat was significantly decreased compared with that of control rat. This deficit results from that myo-inositol transport system which is carrier mediated and sodium-potassium dependent was inhibited by the lead treatment (both 10ppm and 100ppm) due to increase of the Km value without affecting Vmax value for myo-inositol carrier. These observations suggest that the toxic mechanism of lead on nerve myo-inositol transport system might be a change of affinity without change of maximum transport velocity for carrier.

• 대한한방소아과학회지
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• 제17권1호
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• pp.1-16
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• 2003

Background: Delayed mucociliary clearance develops the pooling of nasal secretion in the nasal cavity and is a common cause of vicious cycle of symptoms in chronic sinusitis. mucociliary clearance depends on the ciliary activity, the rheological property of the secretion and on the interaction between cilia and the mucous blanket. Objective: To demonstrate the therapeutic effect of herbal medicine (Hyunggyeyungotang) on the mucociliary transport in the chronic sinusitis using saccharine Materials and methods: Forty patients treated in our hospital between september 2000 and september 2001 were studied. Before and after therapy group are composed of twenty patients. Kamihyunggyeyungyotang was administered mainly. We analyzed the saccharine mucociliary transport time of patients. Results: 1) In the control group, the transport time is about 13.4 minutes. 2) In chronic sinusitis before Kamihyunggyeyungotang therapy, the transport time is about 27.7 minutes. 3) In chronic sinusitis after Kamihyunggyeyungotang therapy, the transport time is about 13.8 minutes. Conclusion: Delayed mucociliary transport time in chronic sinusitis is earlier after Kamihyunggyeyungotang therapy.

• Biomolecules & Therapeutics
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• 제18권1호
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• pp.65-70
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• 2010

The blood-brain barrier (BBB) transport of acetylcholinesterase (AChE) inhibitors, donepezil and tacrine suggested to be mediated by choline transport system in our previous study. Therefore, in the present study, we investigated the interaction of other AChE inhibitors, rivastigmine and galantamine with choline transporter at the BBB. The effects of rivastigmine and galantamine on the transport of choline by conditionally immortalized rat brain capillary endothelial cell lines (TR-BBB cells) were characterized by cellular uptake study using radiolabeled choline. The uptake of [$^3H$]choline was inhibited by rivastigmine and galantamine, with $IC_{50}$ values (i.e. concentration necessary for 50% inhibition) for 1.13 and 1.15 mM, respectively. Rivastigmine inhibited the uptake of [$^3H$]choline competitively with $K_i$ of 1.01 mM, but galantamine inhibited noncompetitively. In addition, the efflux of [$^3H$]choline was significantly inhibited by rivastigmine and galantamine. Our results indicated that the BBB choline transporter may be involved in a part of the influx and efflux transport of rivastigmine across the BBB. These findings should be therapeutically relevant to the treatment of Alzheimer's disease (AD) with AChE inhibitors, and, more generally, to the BBB transport of CNS-acting cationic drugs via choline transporter.