• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.626-629
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• 2001

인간의 뇌에는 천 억개 이상의 신경세포들이 있다. 이들은 신경작용의 매우 복잡한 네트워크를 통해 서로서로 연결되어져 있다. 하나의 신경세포로부터 다른 신경세포로 신호가 전달되는 과정은 다른 화학 전달물질들에 의해 이루어지며 신호 전이는 시냅스라고 불리는 신경세포간의 특정 접촉부 위에서 일어난다. 뉴런의 신호전달 체계에 대한 연구는 20세기 초반에 본격적으로 이루어져 왔으며, 현재는 각 뉴런에 대한 정확한 신호전달 원리를 밝히는데 많은 연구가 이루어지고 있다. 최근에 연구가 활발하게 이루어지고 있는 신경전달 물질중 하나인 일산화 질소는 인간의 세포에 노출되었을 경우 세포막을 기준으로 농도 차가 발생하여 근육이 이완되는 현상을 유발한다. 이런 세포막을 기준으로 한 운동신경 변화, 심장박동의 변화, 근육의 이완철상 및 치명적인 이상을 초래하는 현상을 GENESIS를 이용하여 시뮬레이션 해 보았다.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.135-141
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• 2015

The core melts stratifies into lower mixture layer and upper metal layer by density in a severe accident condition. The decay heat generated from the mixture layer threatens the integrity of the reactor vessel. This study simulated the natural convection heat transfer of the mixture layer with volumetric heat source using the mass transfer system. $H_2SO_4-CuSO_4$ electroplating system was used as the mass transfer system. With the modified Rayleigh number of $3{\times}10^{14}$, the Nusselt number showed minimum at the bottom and increased along curvature to the top of the experimental apparatus.

• Journal of computational fluids engineering
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• v.17 no.3
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• pp.59-67
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• 2012

Large Eddy Simulation(LES) of turbulent mass transfer in fully developed turbulent pipe flow has been performed to study the effect of Reynolds number on the concentration fields at $Re_{\tau}=180$, 395, 590 based on friction velocity and pipe radius. Dynamic subgrid-scale models for the turbulent subgrid-scale stresses and mass fluxes were employed to close the governing equations. Fully developed turbulent pipe flows with constant mass flux imposed at the wall are studied for Sc=0.71. The mean concentration profiles and turbulent intensities obtained from the present LES are in good agreement with the previous numerical and experimental results currently available. The effects of Reynolds number on the turbulent mass transfer are identified in the higher-order statistics(Skewness and Flatness factor) and instantaneous concentration fields. The budgets of turbulent mass fluxes and concentration variance were computed and analyzed to elucidate the effect of Reynolds number on turbulent mass transfer. Furthermore, to understand the correlation between near-wall turbulence structure and concentration fluctuation, we present an octant analysis in the vicinity of the pipe wall.

• Plant Journal
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• v.15 no.1
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• pp.25-30
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• 2019

In this study, by varying flow patterns, which is one of the hydraulic factors of FAC, a strategy to reduce pipe wall thinning by mass transfer has been investigated. A similarity between heat transfer and mass transfer was verified via theoretical analysis, and local convective heat transfer coefficients were analyzed using a commercial numerical analysis program. When ribs were installed inside and outside of the internal surface in the straight section of the pipe, the maximum local heat transfer coefficient was shown to decrease substantially by up to 24.9% compared to the basic flow depending on the position and shape of ribs. If a guide vein was inserted in the pipe elbow, the maximum local heat transfer coefficient decreased by up to 26.7% compared to the basic flow depending on the internal surface area of the pipe by the guide vein.

• Journal of the Korean Magnetics Society
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• v.21 no.2
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• pp.52-55
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• 2011

Spin-transfer torque is a useful tool to control the magnetic state in nanostructures. In magnetic tunnel junctions, the spin-transfer torque has two components, the in-plane spin torque and the perpendicular spin torque. While properties of the in-plane spin-transfer torque are relatively well understood, properties of the perpendicular spin-transfer torque still remain controversial. A recent experiment demonstrated that in asymmetric magnetic tunnel junctions, the bias voltage dependence of the perpendicular spin-transfer torque contains both linear and quadratic terms in the bias. However it still remains unexplored how the bias voltage dependence changes as a function of material parameters. In this paper, we systematically investigate the perpendicular spin-transfer torque in asymmetric magnetic tunnel junction by varying spin splitting energy, work function difference, and Fermi energy of the ferromagnetic metal leads.

• The Microorganisms and Industry
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• v.16 no.1
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• pp.28-39
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• 1990

Biosensor는 모든 종류에서 공히 생체물질로 이루어지는 감지 부분, transducer 그리고 전자부분으로 이루어진다. 따라서 Biosensor는 사용하는 생체물질, transducer로 그리고 측정되는 물질에 따라 분류된다. Biosensor에 이용될 수 있는 생물반응은 pH 변화, ion 생산및 소비, 기체생산및 소비, 발열, 발광, 전자전달, 질량변화 등을 들 수 있다. 이상의 반응을 유발하는 생체물질은 효소, 항체등 단백질과 세포, 조직등 다양하다. 여기에서는 transducer의 특징을 먼저 살펴보고 biosensor 각론에서 이들 생체물질의 반응 특징을 소개한다.

• Bulletin of Korea Environmental Preservation Association
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• s.405
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• pp.17-21
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• 2013

범세계적으로 강화되고 있는 화학물질 및 유해화학물질 함유제품 규제에 대한 기업의 체계적이고 효율적 대응 대책 마련이 시급하다. 이률 위해서는 우선적으로 제품에 함유된 규제 물질을 확인하고 제조공정 유입 및 사용을 차단하기 위한 공급망내 물질정보 생산 관리 전달을 통합 관리하는 사업장 대응시스템 구축이 필요하다.

• Korean Chemical Engineering Research
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• v.58 no.3
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• pp.450-457
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• 2020

In the previous study, there was a big difference between the tendency of the delivery efficiency of Yo-Pro-1 and the expression efficiency of the CFP gene, but there was a problem that could not provide a clue to this problem. Therefore, this study aimed to present a clue to this problem by quantifying and comparing the delivery efficiency after labeling DNA using a fluorescent dye, which was one of the methods for quantifying biomolecules. As a fluorescent dye for labeling, Yo-Pro-1 was used, and the delivery efficiency of the fluorescent dye Yo-Pro-1 and the labeled DNA was compared. The delivery efficiency of Yo-Pro-1 and labeled DNA according to the voltage condition of the digital electroporation system was maximized at 96 V, and the delivery efficiency tended to decrease as the voltage increased further. In the comparison of the delivery efficiency of Yo-Pro-1 and labeled DNA according to the number of voltage application conditions, the delivery efficiency was maximized at the number of 8 voltage application times for both delivery materials, and the delivery efficiency tended to decrease as the number of voltage application increases further. Through the two results, it was confirmed that the delivery efficiency using Yo-Pro-1 in the digital electroporation system represents the delivery efficiency of the system well. In addition, through the results of this study, the difference between the tendency of the delivery efficiency of Yo-Pro-1 and the expression efficiency of the CFP gene shown in the preceding study was not the result of the difference in the delivery efficiency of the delivery material, but it can be predicted to be due to a problem with the expression process of the genetic material that had been delivered.

• Journal of Life Science
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• v.28 no.5
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• pp.597-604
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• 2018

Although the core mechanisms of Attention Deficit/Hyperactivity Disorder (ADHD) are unknown, several ADHD-associated proteins have been studied. G-protein - coupled receptor kinase interacting protein-1 (GIT1) is a multifunctional adapter protein that affects neuron growth and dendrite formation. GIT1-deficient mice have shown ADHD-like behavior and also recovered through amphetamine treatment. In this study, gliotransmitters were investigated in both intracellular and extracellular space from GIT1-deficient mice. To measure the amount of gliotransmitters, primary astrocyte cultures were taken from the cerebral and cerebellar cortices of wild (WT), hetero (HE), and knock-out (KO) mice. Major gliotransmitters were analyzed using high-performance liquid chromatography. It was observed that the amount of excitatory and inhibitory gliotransmitters were dependent on genotype and showed a change in excitation/inhibition ratios. Interestingly, the major excitatory gliotransmitter, glutamate, existed at the lowest level in WT mice, but the amount of inhibitory gliotransmitters, gamma-aminobutyric acid (GABA) and glycine, varied depending on brain region. Remarkably, an increased amount of GABA was measured at the intracellular cerebrum in WT mice compared with KO mice. It was presumed that KO mice would secrete more inhibitory gliotransmitters to compensate for GIT1 depletion or else acquire a defect to reuptake-secreted GABA. This may be a possible mechanism for ADHD pathology.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.11a
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• pp.34-35
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• 1993

Glycine은 GABA와 함께 뇌에 작용하는 중요한 억제성 신경전달 물질이다. GABA가 대뇌등에서 중요한 역할을 하는 반면, GLYCINE은 연수, 척수, 간뇌에 특히 다량 존재한다. GLYCINE은 GLYCINE RECEPTOR에 작용하여 수용체와 연결된 chloride channel의 conductance를 증가시킴으로써 target세포의 활성을 억제한다. 그러므로, glycine의 신경전달체계에 이상이 오면 spastic mouse등에서 볼수 있는 것처럼 neuromuscular disorder가 유발된다. 신경전달 물질은 presynaptic 세포에 자극이 오면 synaptic cleft로 분비가 된후 presynaptic이나 Postsynaptic 세포에 위치한 수용체에 작용하여 생리 활성을 나타내거나, 분해효소에 의해서 생리활성이 없는 물질로 바뀌든지, presynaptic cell에 위치한 transporter(수송체)에 의해서 presynaptic 세포로 reuptake되서 cycle를 끝낸다. Glycine의 경우는 synaptic cleft로 분비된 후 glycine transporter에 의해서 reuptake된다. 그러므로 glycine transporter의 활성 정도는 sysnapse내의 glycine의 농도를 조절하며 더 나아가 glycine이 glycine receptor에 작용하는 시간에 영향을 줌으로써 target 세포의 활성정도를 결정한다.