• Restorative Dentistry and Endodontics
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• 제25권3호
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• pp.407-420
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• 2000

삼차신경절의 뉴런이 구강악안면영역에서의 촉각, 입각, 온도각 및 통각 등 다양한 감각을 중추신경계로 전달하는 역할을 하는 것은 주지의 사실이다. 이러한 신경전달에 있어서 이온통로는 감각정보를 전달하는데 핵심적인 역할을 수행하며 특히 소디움 통로는 활동전위의 발생에 중요하다. 소디움 통로는 tetrodotoxin-sensitive(TTX-s) 및 tetrodotoxin-resistant(TTX-r) 통로로 나누어지는 데 이 중 TTX-r 통로에 발생되는 tetrodotoxin-resistant sodium current(TTX-r $I_{Na}$)는 capsaicin에 민감한 일차구심신경세포에서 유해자극에 의해 통각신호를 발생시키고 전달하는데 중요하다. 또한 칼슘 통로는 시냅스 전도에 있어서 필수적인 역할을 수행하고 있다 한편 치과영역에서 치수의 진정 목적으로 eugenol이 흔히 사용되고 있다. 그러나 eugenol의 그 작용 기전에 대해서 현재까지 이온 통로에 대한 상세한 결과가 없는 실정이며 최근의 보고에 의하면 eugenol이 capsaicin 수용기를 통하여 감각신경에 대한 억제작용을 나타낸다고 한다. 따라서 본 실험은 eugenol과 capsaicin이 흰쥐의 삼차신경절의 TTX-r $I_{Na}$와 칼슘통로에 어떠한 영향을 미치는지를 알아보고 eugenol이 capsaicin 수용기를 통하여 작용하는지를 검증하고자 시행되었다. 삼차신경절 뉴런은 100~150g의 흰쥐의 삼차신경절로부터 외과적으로 절제하여 통법의 화학적 및 기계적 처리를 통해 단일세포로 분리하였고 이를 whole-cell patch clamp 방법을 이용하여 시행한 바 다음과 같은 결론을 얻었다. 1. 1mM의 dugenol은 흰쥐 삼차신경절 뉴런의 TTX-r $I_{Na}$와 HVA $I_{Ca}$를 억제하였다. 2. $1{\mu}m$의 capsaicin은 흰쥐 삼차신경절 뉴런의 TTX-r $I_{Na}$와 HVA $I_{Ca}$를 억제하였다. 3. Capsazepine은 capsaicin의 HVA $I_{Ca}$에 대한 억제작용을 차단하였다. 4. Capsazepine은 capsaicin의 HVA $I_{Ca}$에 대한 억제작용을 차단하지 못하였다. 결론적으로 eugenol과 capsaicin은 tetrodotoxin-resistant sodium current(TTX-r $I_{Na}$)와 high voltage-activated calcium current(HVA $I_{Ca}$)를 모두 억제하는 것으로 나타났으며, 이러한 작용이 통각의 발생과 시냅스 전달과정을 차단하여 치수 진정 목적으로 많이 사용하는 eugenol의 작용기전으로 판단된다. 한편 capsaicin의 길항제인 capsazepine을 전처치하였을 때에도 eugenol의 HVA $I_{Ca}$에 대한 억제효과는 변화가 없었다. 이와같은 결과로 보아 HVA $I_{Ca}$에 관한 한 eugenol은 capsaicin 수용기를 통하여 나타나지 않는 것으로 사료된다.

• 한국표면공학회지
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• 제49권2호
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• pp.166-171
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• 2016

Cathodic protection is widely recognized as the most cost effective and technically appropriate corrosion prevention methodology for the port, offshore structures, ships. When applying the cathodic protection method to metal facilities in seawater, on the surface of the metal facilities a compound of calcium carbonate($CaCO_3$) or magnesium hydroxide($Mg(OH)_2$) films are formed by $Ca^{2+}$ and $Mg^{2+}$ ions among the many ionic components dissolving in the seawater. And calcareous deposit films such as $CaCO_3$ and $Mg(OH)_2$ etc. are formed by the surface of the steel product. These calcareous deposit film functions as a barrier against the corrosive environment, leading to a decrease in current demand. On the other hand, the general calcareous deposit film is a compound like ceramics. Therefore, there may be some problems such as weaker adhesive power and the longer time of film formation uniting with the base metal. In this study, we tried to determine and control the optimal condition through applying the principle of cathodic current process to form calcareous deposit film of uniform and compact on steel plate. The quantity of precipitates was analyzed, and both the morphology, component and crystal structure were analyzed as well through SEM, EDS and XRD. And based on the previous analysis, it was elucidated mechanism of calcareous deposit film formed in the sacrificial anode type (Al, Zn) and current density (1, 3, $5A/m^2$) conditions. In addition, the taping test was performed to evaluate the adhesion.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.346-350
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• 2002

The effect of Ca-doping on the superconducting properties of Nd-Ba-Cu-O bulk superconductors, fabricated by the oxygen-controlled melt growth process, has been systematically investigated. Various c-axis textured bulk samples were grown using precursors with the nominal compositions of N $d_{1.8-x}$C $a_{x}$B $a_{2.4}$C $u_{3.4}$ $O_{y}$ (x = 0.00, 0.02, 0.05, 0.10, 0.15) in a reduced oxygen atmosphere of 1% $O_2$ in Ar. Magnetization measurements revealed that the critical temperatures( $T_{c}$) were almost linearly depressed from 95K to 86K with increasing the Ca dopant from x = 0.0 to 0.15, respectively, and thus critical current densities( $J_{c}$) at 77K and for H//c-axis of specimens were gradually degraded with increasing x. Compositional analyses revealed that although the amounts of the Ca dopant both in NdB $a_2$C $u_3$ $O_{y}$(Nd123) and N $d_4$B $a_2$C $u_2$ $O_{10}$(Nd422) were increased with increasing x, only less than half of the initial Ca compositions were detected in melt-grown Ca-doped Nd-Ba-Cu-O bulk crystals. The supression of $T_{c}$ is attributed to an increased Nd substitution for the Ba site in the Nd123 superconducting matrix with increasing the amount of the Ca dopant.t.opant.t.t.t.t.t.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.652-655
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• 2001

Power transformers are increasingly becoming more significant in the advancement of electronic equipment. A high-performance, low-cost core material is necessary in order th come up with power transformers in the smallest and lightest scale possible and with low power requirements. In this study, we added V$_2$O$_{5}$ and CaCo$_3$to Mn-Zn ferrite to produce a high-performance low-cost core material. The compositions used were MnO : ZnO : Fe$_2$O$_3$= 37 : 11 : 52 mol%. The materials were sintered at 125$0^{\circ}C$ for three hours. Initial permeability was measured at 0.1MHz. At 200mT, power loss was measured by changing the temperature at 25KHz, 50KHz, 100KHz. When we added 0.lwt% and 0.1%wt% of V$_2$O$_{5}$와 CaCo$_3$, respectively we obtained 405 405KW/㎥ at 200mT, 100KHz, 6$0^{\circ}C$. We tan reduce eddy current loss as a primary loss of high frequency by adding a small amount of V$_2$O$_{5}$와 CaCo$_3$. This reduces power loss in the power transformersormers

• 한국전기전자재료학회논문지
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• 제17권7호
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• pp.788-792
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• 2004

The Electromagnetic properties in BiPbSrCaCuO superconductor was studied. In the measurement of current-voltage characteristics, a voltage across the superconducting sample was observed on applying an external magnetic field. The voltage continues to appear the removal of the magnetic field. The appearance of the voltage is ascribed to the trapping of magnetic flux. Depanding on the direction of appied magnetic flux less than $2.5\times{10}^-5$ T, the voltage in the magnetized sample increases or decreases. It is considered that mechanism of voltage occurrence can be explained by applying filament model.

• The Korean Journal of Physiology and Pharmacology
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• 제22권6호
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• pp.697-703
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• 2018

Myoblast fusion depends on mitochondrial integrity and intracellular $Ca^{2+}$ signaling regulated by various ion channels. In this study, we investigated the ionic currents associated with $[Ca^{2+}]_i$ regulation in normal and mitochondrial DNA-depleted(${\rho}0$) L6 myoblasts. The ${\rho}0$ myoblasts showed impaired myotube formation. The inwardly rectifying $K^+$ current ($I_{Kir}$) was largely decreased with reduced expression of KIR2.1, whereas the voltage-operated $Ca^{2+}$ channel and $Ca^{2+}$-activated $K^+$ channel currents were intact. Sustained inhibition of mitochondrial electron transport by antimycin A treatment (24 h) also decreased the $I_{Kir}$. The ${\rho}0$ myoblasts showed depolarized resting membrane potential and higher basal $[Ca^{2+}]_i$. Our results demonstrated the specific downregulation of $I_{Kir}$ by dysfunctional mitochondria. The resultant depolarization and altered $Ca^{2+}$ signaling might be associated with impaired myoblast fusion in ${\rho}0$ myoblasts.

• The Korean Journal of Physiology and Pharmacology
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• 제12권6호
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• pp.337-342
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• 2008

Human bone marrow mesenchymal stem cells (hBM-MSCs) represent a potentially valuable cell type for clinical therapeutic applications. The present study was designed to evaluate the effect of long-term culturing (up to $10^{th}$ passages) of hBM-MSCs from eight individual amyotrophic lateral sclerosis (ALS) patients, focusing on functional ion channels. All hBM-MSCs contain several MSCs markers with no significant differences, whereas the distribution of functional ion channels was shown to be different between cells. Four types of $K^+$ currents, including noise-like $Ca^{+2}$-activated $K^+$ current ($IK_{Ca}$), a transient outward $K^+$ current ($I_{to}$), a delayed rectifier $K^+$ current ($IK_{DR}$), and an inward-rectifier $K^+$ current ($K_{ir}$) were heterogeneously present in these cells, and a TTX-sensitive $Na^+$ current ($I_{Na,TTX}$) was also recorded. In the RT-PCR analysis, Kv1.1,, heag1, Kv4.2, Kir2.1, MaxiK, and hNE-Na were detected. In particular, ($I_{Na,TTX}$) showed a significant passage-dependent increase. This is the first report showing that functional ion channel profiling depend on the cellular passage of hBM-MSCs.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.416-419
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• 2002

There are being two prominent studying for Digital Radiography. Direct and Indirect method of Digital Radiography are announced for producing high quality digital image. The one is using amorphous selenium as photoconductor and the other is using phosphor layer as a light conversion. But each two systems have strength and weakness such as high voltage and blurring effect. In this study, we investigated the electrical characteristic of $multi-layer\left(CaWO_{4}+a-Se \right)$ as a photoconductor according to the changing arsenic composition ratio. This is a basic research for developing of Hybrid digital radiography which is a new type X-ray detector. The arsenic composition ratio of a-Se compound is classified into 7 different kinds which have 0.1%, 0.3%, 0.5%, 1%, 1.5%, 5%, 10% and were made test sample throught thermo-evaporation. The phosphor layer of $CaWO_4$ was overlapped on a-Se using EFIRON optical adhesives. We measured the dark and photo current about the test sample and compared the electrical characteristic of the net charge and signal-to-noise ratio. Among other things, test sample of compound material of 0.3% arsenic showed good characteristic of $2.45nA/cm^2$ dark current and $357.19pC/cm^2/mR$ net charge at $3V/{\mu}m$.

• 동의생리병리학회지
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• 제27권1호
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• pp.112-117
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• 2013

We studied the modulation of pacemaker activities by Samchulkunbi-tang (SCKB) in cultured interstitial cells of Cajal (ICC) from murine small intestine with the whole-cell patch-clamp technique. Externally applied SCKB produced membrane depolarization in the current-clamp mode. The pretreatment with $Ca^{2+}$-free solution and thapsigargin, a $Ca^{2+}$-ATPase inhibitor in endoplasmic reticulum, abolished the generation of pacemaker potentials and suppressed the SCKB-induced action. The application of flufenamic acid (a nonselective cation channel blocker) abolished the generation of pacemaker potentials by SCKB. However, the application of niflumic acid (a chloride channel blocker) did not inhibit the generation of pacemaker potentials by SCKB. In addition, the membrane depolarizations were inhibited by not only GDP-${\beta}$-S, which permanently binds G-binding proteins, but also U-73122, an active phospholipase C inhibitor. These results suggest that SCKB modulates the pacemaker activities by nonselective cation channels and external $Ca^{2+}$ influx and internal $Ca^{2+}$ release via G-protein and phospholipase C-dependent mechanism. Therefore, the ICC are targets for SCKB and their interaction can affect intestinal motility.

• 대한약침학회지
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• 제16권4호
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• pp.36-42
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• 2013

Objectives: Shengmaisan (SMS) is a traditional Chinese medicine prescription widely used for the treatment of diverse organs in Korea. The interstitial cells of Cajal (ICCs) are pacemaker cells that play an important role in the generation of coordinated gastrointestinal (GI) motility. We have aimed to investigate the effects of SMS in the ICCs in the mouse small intestine. Methods: To dissociate the ICCs, we used enzymatic digestions from the small intestine in a mouse. After that, the ICCs were identified immunologically by using the anti-c-kit antibody. In the ICCs, the electrophysiological whole-cell patch-clamp configuration was used to record pacemaker potentials in the cultured ICCs. Results: The ICCs generated pacemaker potentials in the mouse small intestine. SMS produced membrane depolarization with concentration-dependent manners in the current clamp mode. Pretreatment with a $Ca^{2+}$ free solution and thapsigargin, a $Ca^{2+}$-ATPase inhibitor in the endoplasmic reticulum, stopped the generation of the pacemaker potentials. In the case of $Ca^{2+}$-free solutions, SMS induced membrane depolarizations. However, when thapsigargin in a bath solution was applied, the membrane depolarization was not produced by SMS. The membrane depolarizations produced by SMS were inhibited by U-73122, an active phospholipase C (PLC) inhibitors. Furthermore, chelerythrine and calphostin C, a protein kinase C (PKC) inhibitors had no effects on SMS-induced membrane depolarizations. Conclusions: These results suggest that SMS might affect GI motility by modulating the pacemaker activity through an internal $Ca^{2+}$- and PLC-dependent and PKC-independent pathway in the ICCs.