• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1996년도 정기총회 및 학술발표회
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• pp.5-5
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• 1996

In sino-atrial node cells which act as the normal pacemaker of the heart, K conductance in resting state is minimal due to the absence of inward rectifier K channels K conductance only increases when the membrane is depolarized by the activation of the delayed rectifier K current I$\_$k/. In the present study, we investigated the gating mechanism of$\_$k/ using the whole cell patch clamp technique in isolated single sinoatrial cells of the rabbit. (omitted)

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2001년도 학술 발표회 진행표 및 논문초록
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• pp.55-55
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• 2001

We observed the APD of rat ventricle myocyte and the effects of Lithospermic acid that was separated at Salvia miltiorrhiza having used in Oriental medicine by using classical whole cell patch clamp technique. We classified APD into APD30mV, APD0mV, APD-50mV, APD-60mV by cell membrane potential and the mean of cell resting membrane potential was -69.44${\pm}$1.72 mV.(omitted)

• The Korean Journal of Physiology
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• 제27권2호
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• pp.151-162
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• 1993

In order to investigate the effect of intracellular cyclic GMP on calcium current the whole-cell patch clamp technique with internal perfusion method was used in isolated ventricular myocytes of the rabbit. Cyclic GMP, 8-bromo-cyclic GMP, cyclic AMP, isoprenaline and forskolin were perfused into cells and their effects on calcium current were analysed by applying depolarizing step pulses of + 10 mV in amplitude far 300 msec from holding potential of - 40 mV. Not only cyclic AMP $(100\;{\mu}M)$ but also cyclic GMF $(100\;{\mu}M)$ increased the basal calcium current. 8-Bromo-cyclic GMP $(100\;{\mu}M)$, a good stimulator of the cyclic GMP-dependent protein kinase, also increased the basal calcium current and its peak amplitude of calcium current was larger than that in the presence of cyclic AMP or cyclic GMP alone. In the presence of $100\;{\mu}M$ cyclic GMP or $100\;{\mu}M$ 8-bromo-cyclic GMP, already augmented calcium current was potentiated by intracellular application of $100\;{\mu}M$ cyclic AMP or $1\;{\mu}M$ isoprenaline or $1\;{\mu}M$ forskolin. In the presence of cyclic GMP, acetylcholine reduced the calcium current only when the calcium current was increased by isoprenaline. From the above results it could be concluded that intracellular perfusion with cyclic GMP increases the basal calcium current via a mechanism involving a cyclic GMP-dependent protein kinase.

• 전기전자학회논문지
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• 제15권1호
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• pp.49-56
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• 2011

본 논문에서는 고주파 발진회로의 공진기를 패치 안테나로 사용하는 능동발진 안테나를 2.4GHz 대역에서 제안하여 소형 무선도플러 센서로서 이동체의 거리나 속도 등을 측정할 수 있게 하였다. 이동체의 움직임은 고주파 발진 주파수의 천이를 발생시키며 이를 검출하는 회로를 통해 제안된 구조의 동작을 확인하였다. 설계 제작된 무선 도플러 센서는 직경이 30mm, 높이 4.2mm 정도로 매우 작은 원형디스크 형태를 갖으며, 안테나는 2.373GHz에서 약 130도의 빔폭과 전방향 방사특성을 나타내었다. 센서의 감도 측정결과, 1m 떨어져 움직이고 있는 도체판에 대해 최소 190mV의 도플러 신호 전압을 얻었고, 센서의 자유낙하 실험으로부터 지표상의 4.5m 지점에서 부터 지표면까지 전압크기가 선형적으로 증가하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제1권6호
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• pp.741-748
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• 1997

In the present study, we have investigated the effect of metabolic inhibition on the inward rectifier K current ($I_{K1}$). Using whole cell patch clamp technique we applied voltage ramp from +80 mV to -140 mV at a holding potential of -30 mV and recorded the whole cell current in single ventricular myocytes isolated from the rabbit heart. The current-voltage relationship showed N-shape (a large inward current and little outward current with a negative slope) which is a characteristic of $I_{K1}$. Application of 0.2 mM dinitrophenol (DNP, an uncoupler of oxidative phosphorylation as a tool for chemical hypoxia) to the bathing solution with the pipette solution containing 5 mM ATP, produced a gradual increase of outward current followed by a gradual decrease of inward current with little change in the reversal potential (-80 mV). The increase of outward current was reversed by glibenclamide ($10\;{\mu}M$), suggesting that it is caused by the activation of $K_{ATP}$. When DNP and glibenclamide were applied at the same time or glibenclamide was pretreated, DNP produced same degree of reduction in the magnitude of the inward current. These results show that metabolic inhibition induces not only the increase of $K_{ATP}$ channel but also the decrease of $I_{K1}$. Perfusing the cell with ATP-free pipette solution induced the changes very similar to those observed using DNP. Long exposure of DNP (30 min) or ATP-free pipette solution produced a marked decrease of both inward and outward current with a significant change in the reversal potential. Above results suggest that the decrease of $I_{K1}$ may contribute to the depolarisation of membrane potential during metabolic inhibition.

• The Korean Journal of Physiology and Pharmacology
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• 제2권2호
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• pp.165-172
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• 1998

Under certain pathophysiological conditions, such as inflammation and ischemia, the concentration of H^+$ ion in the tissue surrounding neurons is changed. Variations in H^+$ concentration are known to alter the conduction and/of the gating properties of several types of ion channels. Several types of K^+$ channels are modulated by pH. In this study, the whole cell configuration of the patch clamp technique has been applied to the recording of the responses of change of external pH on the delayed rectifier K^+$ current of cultured DRG neurons of rat. Outward K^+$ currents were examined in DRG cells, and the Charybdotoxin and Mn^{2+}$ could eliminate Ca^{2+}-dependent$ K^+$ currents from outward K^+$ currents. This outward K^+$ current was activated around -60 mV by step depolarizing pulses from holding potential -70 mV. Outward K^+$ currents were decreased by low external pH. Activation and steady-state inactivation curve were shifted to the right by acidification, while there was small change by alkalization. These results suggest that H^+$ could be alter the sensory modality by changing and modifying voltage-dependent K^+$ currents, which participated in repolarization.

• The Korean Journal of Ecology
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• 제12권3호
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• pp.171-182
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• 1989

The structure, clonal grwoth, shoot modules dynamics and rhizome respiratory rate of the Phragmites longivalvis circular patch were studied in a 15-year-old reclaimed land on Mado of the western Korea for two growing seasons. Clonal growth by P. longivalvis resulted in subpopulations of shoot modules which may be separated into pioneer, mature and senile growth phase. The radial growth of circular patch was 208 cm per a year. The shoot phytomass, shoot height and spike frequency were the lowest in the senile phase, and were the highest in the mature phase. The maximum shoot phytomass of pioneer, mature and senile phase in August was 347, 536 and 195g/$\m^2$ for the first year, and 609, 748 and 248g/$\m^2$ for the second year, respectively. The birth rates of shoot modules were the highest during the early spring. Of all modules, the percemtage of spring cohort of pioneer, mature and senile growth phase were 52, 82 and 70% for the first year, and 83, 88 and 85% for the second year, respectively. The flowering shoots were only derived from spring cohorts. The death rates of shoot modules of the pioneer and mature phase were the highest in October. The module is an annual semelparous plant though the genet is a perennial iteroparous plant. Their survivorship curve was negatively (Deevey type I). The density of shoot modules of the pioneer, mature and senile growth phase increased as much as 4.0, 1.6 and 2.3 times for one year, respectively. The respiratory rate was the highest in the lowest in the senile growth phase.

• 한국전자파학회논문지
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• 제27권3호
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• pp.299-306
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• 2016

본 논문에서는 공진기와 인체와의 거리에 따른 근접 전자기장 변화에 의한 공진기 임피던스의 변화를 토대로 사람의 호흡 및 심박신호를 검출할 수 있는 센서를 제안한다. 제안된 생체신호 측정센서는 패치형 공진기가 결합된 발진기, 발진주파수의 2채배 주파수만 통과시키기 위한 다이플렉서, 증폭기, SAW 필터 및 RF 검출기로 구성되어 있다. 호흡과 심박신호와 같은 인체의 주기적인 움직임은 근접 전자기장 영역 안에서 공진기의 임피던스 변화를 야기하며, 발진기의 주파수를 변화시킨다. 감도를 향상시키기 위해 발진주파수의 2채배 주파수 천이를 SAW 필터의 저지대역에 위치시킴으로써, 제안된 센서의 검출 거리를 2배로 확장시킬 수 있다. 제안된 센서의 측정결과, 최대 40 mm까지 호흡 및 심박신호가 안정적으로 측정되는 것을 확인하였다.

• 한국전자파학회논문지
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• 제21권6호
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• pp.698-705
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• 2010

AM, FM, TDMB, GPS 수신용 자동차 전장 안테나를 설계하고 이를 제작하였다. AM 안테나는 페라이트 턴스타일 안테나로 설계하여 전방향 특성을 갖도록 하였다. FM, TDMB 수신용으로는 헤리컬 소자를 접은 접힌 모노폴 안테나로 설계하였다. 대역 확보를 위한 GPS 수신 안테나는 공기층 사다리꼴 마이크로스트립 패치 안테나로 설계하였다. 제작된 AM 수신용 안테나의 수신 신호 세기는 -65.7 dBm으로 기존의 외장형 폴 안테나의 -63.5 dBm과 비교하면 소형이면서도 유사한 수신 성능을 나타냄으로써 외장형 폴 안테나 및 glass 안테나 대체 품으로 적용할 수 있음을 보였다. FM 및 TDMB 수신 신호 세기는 각각의 중심 주파수에서 -55.66 dBm, -43.50 dBm 측정됨으로써 기존 안테나에 비해 5~10 dB 높은 특성이 나타났다. GPS 안테나에 대한 측정은 VSWR 2 : 1 기준으로 135 MHz의 넓은 대역 특성과 4.31 dBi의 이득이 측정되어, GPS 전 대역에서 일반 세라믹 패치 안테나의 이득보다 3~5 dB 높은 이득을 얻었다.

• Journal of Chest Surgery
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• 제25권4호
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• pp.364-382
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• 1992

In order to investigate the effect of intracellular cyclic GMP on the calcium channel, whole cell patch clamp technique with internal perfusion method was used in the single ventricular myocytes of the rabbit. Cyclic GMP, cGMP analogues, cAMP, isopernaline and forskolin were perfused into cells and their effects on the calcium current were analysed by applying depolarizing step pulse of 10 mV in amplitude for 200 msec from holding potential of -40 mV. Calcium currents usually activated from -30 mV and then reached a peak at +10 mV. Amplitude of the calcium current was standardized with membrane capacitance, 50 pF. Peak amplitude at +10 mV in control was -0.15 nA/50pF. When 100 mM cAMP was applied from the pipette, peak amplitude of calcium current increased to -0.32 nA and addition of 1 mM isoprenaline further increased its amplitude. In the presence of cGMP it alone also produced an increase of the calcium current to -0.52 nA/50pF and addition of isoprenaline or forskolin increased its magnitude to -[0.55~0.95] nA/50pF. Simultaneous application of cGMP and cAMP increased the calcium current to -0.67 nA/50pF. Among the cGMP analogues, 8-Br-cGMP was the most potent stimulant for the calcium current activation. From the above results it could be concluded tlat cGMP increases the calcium current not through cAMP dependent protein kinase nor cAMP dependent phosphodiesterase pathway, but through independent phosphorylation pathway, possibly cGMP dependent protein kinase pathway.