• 대한약리학회:학술대회논문집
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• 대한약리학회 2006년도 The 6th Congress of the Federation of Asian and Oceanian Physiological Societies
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• pp.86.1-86.1
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• 2006

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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• pp.34-34
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• 2002

Oxidative stress has been considered as a major cause of inducing cell damage, but it is recently recognized that mild oxidative stress or receptor-mediated production of ROS contributes to the regulation of various cellular functions. Several ion channels, such as L-type $Ca^{2＋}$ channels and $Ca^{2＋}$-activated $K^{＋}$ channels, have been shown to be regulated by oxidation of thiol group in their structure, and are suggested to be involved in ROS-sensitive cellular signaling.(omitted)

• 한국수정란이식학회지
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• 제22권3호
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• pp.149-154
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• 2007

임신의 성립 및 유지에 중요한 역할을 하는 자궁내막세포에 $K_{2P}$ 통로의 존재를 확인하기 위하여 본 연구를 수행하였다. $K_{2P}$ 통로는 일반적으로 중추신경계에 풍부하게 존재하면서 세포의 안정막 전압을 유지시킨다. 역전사 중합 효소 중합 반응과 면역 세포 화학 염색 방법을 이용하여 자궁내막세포에 존재하는 $K_{2P}$ 통로를 조사한 결과, TASK-1, TASK-3, TREK-1, TREK-2 및 TRAAK의 발현이 확인되었다. TASK-3와 TREK-1은 핵을 포함한 세포 전역에 발현하였고, TREK-2와 TRAAK은 핵을 제외한 세포 전역에 발현하였다. 그러나 자궁내막염이 있는 자궁내막세포와 정상 자궁내막세포에서 $K_{2P}$ 통로의 발현 변화를 비교한 결과, 두 군간의 mRNA 발현 수준이 변화하지 않았다. 본 연구는 한우의 자궁내막세포에서 $K_{2P}$ 통로의 존재를 처음으로 보고하는데, 이를 통하여 한우의 자궁내막세포에서 확인된 $K_{2P}$ 통로들은 자궁의 생리 작용과 자궁암 등과 같은 여러 자궁 관련 질병에 관여할 가능성이 높을 것으로 생각된다.

• 한국분말재료학회지
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• 제18권4호
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• pp.327-331
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• 2011

In order to fabricate the porous metal with controlled pore characteristics, unique processing by using metal oxide powder as the source and camphene as the sublimable material is introduced. CuO powder was selected as the source for the formation of Cu metal via hydrogen reduction. Camphene-based CuO slurry, prepared by milling at $47^{\circ}C$ with a small amount of dispersant, was frozen at $-25^{\circ}C$. Pores were generated subsequently by sublimation of the camphene. The green body was hydrogen-reduced at $200^{\circ}C$ for 30 min, and sintered at $500-700^{\circ}C$ for 1 h. Microstructural analysis revealed that the sintered Cu showed aligned large pore channels parallel to the camphene growth direction, and fine pores are formed around the large pore. Also, it showed that the pore size was controllable by the slurry concentration.

• Transactions on Electrical and Electronic Materials
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• 제12권3호
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• pp.119-122
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• 2011

A series of mesoporous silicalites was synthesized using different compositions of tetraethylorthosilicate and methyltriethoxysilane (MTES) as the silica source. Cetyltrimethylammonium bromide was used as the organic template. Their detailed pore structures were investigated by transmission electron microscopy, X-ray diffraction, and N2 adsorption method. The thermal properties of these silicalites were studied by thermogravimetric analysis. The increased amount of MTES destroyed mesoporous channels and reduced pore sizes from 3.4 nm to 2.8 nm in calcined silicalites. The calcined silicalite transformed completely into an amorphous state at 30% MTES loading. Methyl pending groups of MTES hindered the structural ordering of ≡Si-O- frameworks, resulting in an amorphous structure. This was caused by the insufficient formation of supramolecular assembly with the organic template. No capillary condensation step was found in MS 7/3 silicalite. The other capillary condensation steps shifted toward the lower relative pressure with increasing MTES content, indicating the reduction of pore sizes.

• 한국세라믹학회지
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• 제41권3호
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• pp.229-234
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• 2004

수계슬러리의 동결건조 공정을 이용하여 배향성 기공을 갖는 NiO-YSZ 지지체를 제조하였다. 슬러리의 동결과정에서 형성된 얼음 결정은 진공건조 과정을 거치면서 승화되어 그 자리에 기공을 형성하였으며. 열전달 방향과 속도를 조절함으로써 얼음결정의 성장을 제어할 수 있음을 알 수 있었다. 제조된 NiO-YSZ 지지체는 배향성을 가진 거대(macro) 기공과 함께 표면에는 미세기공이 존재하는 독특한 기공구조를 형성하였다. 이것은 동결과정에 있어서 성형체의 위치에 따라 얼음의 성장속도가 다르기 때문에 발생하는 현상으로 생각된다. 얻어진 다공체 표면에 YSZ 슬러리를 dip 코팅하여 막을 형성한 후 140$0^{\circ}C$에서 동시소성(co-firing)하여 다공성 NiO-YSZ 지지체의 표면에 치밀한 YSZ 막이 코팅된 bilayer 제조에 성공하였다.

• 멤브레인
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• 제7권3호
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• pp.142-149
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• 1997

비대칭형 막기공을 통한 뉴톤 유체의 발산흐름(diverging flow)에 대한 심도있는 해석 결과를 제시하였다. 막기공 모델의 일반적 형태인 슬릿(slit)과 원뿔(cone)형 채널에 대해 미동흐름(creeping flow)을 적용하여 유속분포 관계식을 구하였다. 유속분포의 고찰로부터 발산각도 $\alpha$$\longrightarrow$0 인 경우는 윤활근사법(lubrication approximation)이 적용되어 Poiseuille 흐름으로 되는 것을 확인하였고, 발산각도가 증가할수록 벽면부근에서의 유속분포는 결핍(depletion)됨과 아울러 전체유속은 감소하였다. 구해진 속도분포와 압력분포의 관계식으로부터 투과유량에 대한 이론식을 도출하였다. 예측된 결과는 기공의 비대칭성이 증가할수록 그에 따른 투과유량은 점차 증가하는 거동을 보였다. 본 연구의 이론결과는 궁극적으로 막여과에의 응용 측면과 밀접하게 연관되어 있다.

• Molecules and Cells
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• 제25권2호
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• pp.242-246
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• 2008

To assess the role of $\alpha_{1G}$ T-type $Ca^{2+}$ channels in neuropathic pain after L5 spinal nerve ligation, we examined behavioral pain susceptibility in mice lacking $Ca_{V}3.1$ (${\alpha}_{1G}{^{-/-}}$), the gene encoding the pore-forming units of these channels. Reduced spontaneous pain responses and an increased threshold for paw withdrawal in response to mechanical stimulation were observed in these mice. The ${{\alpha}_{1G}}^{-/-}$ mice also showed attenuated thermal hyperalgesia in response to both low-(IR30) and high-intensity (IR60) infrared stimulation. Our results reveal the importance of ${\alpha}_{1G}$ T-type $Ca^{2+}$ channels in the development of neuropathic pain, and suggest that selective modulation of ${\alpha}_{1G}$ subtype channels may provide a novel approach to the treatment of allodynia and hyperalgesia.

• The Korean Journal of Physiology and Pharmacology
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• 제22권1호
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• pp.71-80
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• 2018

In patients with epilepsy, depression is a common comorbidity but difficult to be treated because many antidepressants cause pro-convulsive effects. Thus, it is important to identify the risk of seizures associated with antidepressants. To determine whether paroxetine, a very potent selective serotonin reuptake inhibitor (SSRI), interacts with ion channels that modulate neuronal excitability, we examined the effects of paroxetine on Kv3.1 potassium channels, which contribute to high-frequency firing of interneurons, using the whole-cell patch-clamp technique. Kv3.1 channels were cloned from rat neurons and expressed in Chinese hamster ovary cells. Paroxetine reversibly reduced the amplitude of Kv3.1 current, with an $IC_{50}$ value of $9.43{\mu}M$ and a Hill coefficient of 1.43, and also accelerated the decay of Kv3.1 current. The paroxetine-induced inhibition of Kv3.1 channels was voltage-dependent even when the channels were fully open. The binding ($k_{+1}$) and unbinding ($k_{-1}$) rate constants for the paroxetine effect were $4.5{\mu}M^{-1}s^{-1}$ and $35.8s^{-1}$, respectively, yielding a calculated $K_D$ value of $7.9{\mu}M$. The analyses of Kv3.1 tail current indicated that paroxetine did not affect ion selectivity and slowed its deactivation time course, resulting in a tail crossover phenomenon. Paroxetine inhibited Kv3.1 channels in a use-dependent manner. Taken together, these results suggest that paroxetine blocks the open state of Kv3.1 channels. Given the role of Kv3.1 in fast spiking of interneurons, our data imply that the blockade of Kv3.1 by paroxetine might elevate epileptic activity of neural networks by interfering with repetitive firing of inhibitory neurons.

• 한국분말재료학회지
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• 제27권4호
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• pp.325-332
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• 2020

In this study, the effects of kaolin addition on the properties of reticulated porous diatomite-kaolin composites are investigated. A reticulated porous diatomite-kaolin composite is prepared using the replica template method. The microstructure and pore characteristics of the reticulated porous diatomite-kaolin composites are analyzed by controlling the PPI value (45, 60, and 80 PPI) of the polyurethane foam (which are used as the polymer template), the ball-milling time (8 and 24 h), and the amount of kaolin (0-50 wt. %). The average pore size decreases as the amount of kaolin increases in the reticulated porous diatomite-kaolin composite. As the amount of kaolin increases, it can be determined that the amount of inter-connected pore channels is reduced because the plate-shaped kaolin particles connect the gaps between irregular diatomite particles. Consequently, a higher kaolin percentage affects the overall mechanical properties by improving the pore channel connectivity. The effect of kaolin addition on the basic properties of the reticulated porous diatomite-kaolin composite is further discussed with characterization data such as pore size distribution, scanning electron microscopy images, and compressive strength.