• The Korean Journal of Physiology
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• 제17권1호
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• pp.1-11
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• 1983

1) 토끼동방결절의 작은 절편에 미세 전극 두개로 voltage clamp를 하고 과분극에 의하여 활성화되는 내향전류, $i_f$의 동력학적 성상을 분석하였다. 2) 전류 $i_f$는 $10^{-7}g/ml$ TTX와 2 mM $Mn^{2+}$의 존재하에서 과분극 pulse에 의하여 활성화되었으며 그 범위는 $-45\;mV{\sim}-75\;mV$였다. 전류의 크기와 시간경과는 막전압이 과분극될수록 커지고 빨라졌다. 3) Envelope test결과 $i_f$전류는 단일 gate에 의하여 지수합수적 (exponential)으로 조절됨을 보였다. 4) 2 mM의 $Ba^{2+}$에 의하여$i_f$전류의 크기는 감소하고 시간경과도 느려졌으며 반응속도상수와 gating molecule의 열리고 닫히는 반응계수(rate coefficient; ${\alpha}_s$, ${\beta}_s$)와 막전압 관계곡선을 과분극쪽으로 이동시켰다. 이러한 $Ba^{2+}$의 효과는 24 mM $K^+$에 의하여 일부 상쇄되었다.

• 운동영양학회지
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• 제24권1호
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• pp.9-13
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• 2020

[Purpose] This preliminary study aimed to develop a regression model to estimate the resting metabolic rate (RMR) of young and middle-aged Koreans using various easy-to-measure dependent variables. [Methods] The RMR and the dependent variables for its estimation (e.g. age, height, body mass index, fat-free mass; FFM, fat mass, % body fat, systolic blood pressure, diastolic blood pressure, mean arterial pressure, pulse pressure, and resting heart rate) were measured in 53 young (male n = 18, female n = 16) and middle-aged (male n = 5, female n = 14) healthy adults. Statistical analysis was performed to develop an RMR estimation regression model using the stepwise regression method. [Results] We confirmed that FFM and age were important variables in both the regression models based on the regression coefficients. Mean explanatory power of RMR₁ regression models estimated only by FFM was 66.7% (R²) and 66.0% (adjusted R²), while mean standard errors of estimates (SEE) was 219.85 kcal/day. Additionally, mean explanatory power of RMR₂ regression models developed by FFM and age were 70.0% (R²) and 68.8% (adjusted R²), while the mean SEE was 210.64 kcal/day. There was no significant difference between the measured RMR by the canopy method using a metabolic gas analyzer and the predicted RMR by RMR₁ and RMR₂ equations. [Conclusion] This preliminary study developed a regression model to estimate the RMR of young and middle-age healthy Koreans. The regression model was as follows: RMR₁ = 24.383 × FFM + 634.310, RMR₂ = 23.691 × FFM - 5.745 × age + 852.341.

• 분석과학
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• 제10권3호
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• pp.187-195
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• 1997

[16]-ane-$S_4$/탄소분말 함량비를 50%로 하여 nujol oil과 혼합하여 수식전극을 제조하였다. $5.0{\times}10^{-4}M$ $Ag^+$를 포함하는 pH 4.5인 아세트 완충용액에 수식전극을 담가 $Ag^+$를 전극 표면에 흡착시켰다. 이 때 흡착시간을 15분으로 하고 전해환원시키는 시간은 -0.3V vs S.C.E에서 2분으로 하였다. 또한 0.1M $HNO_3$ 용액으로 전극을 활성화시켰으며 한번 활성화한 전극은 10회까지 사용이 가능하였다. 최적 분석조건에서 미분펄스 전압전류법으로 $5.0{\times}10^{-7}{\sim}1.5{\times}10^{-6}M$ 사이의 농도 범위에서 정량해 보았을 때 직선성이 잘 성립하였으며, 검출한계는 $2.0{\times}10^{-7}M$이었다. 대부분의 금속들은 방해를 주지 않았으나, Cu(II)은 방해를 나타내었다.

• Journal of Gastric Cancer
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• 제22권4호
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• pp.395-407
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• 2022

Purpose: This study aimed to investigate the relationship between clinical and laboratory parameters and complication status to predict which patients can be safely discharged from the hospital on the third postoperative day (POD). Materials and Methods: Data from a prospectively maintained database of 2,110 consecutive patients with gastric adenocarcinoma who underwent curative surgery were reviewed. The third POD vital signs, laboratory data, and details of the course after surgery were collected. Patients with grade II or higher complications after the third POD were considered unsuitable for early discharge. The performance metrics were calculated for all algorithm parameters. The proposed algorithm was tested using a validation dataset of consecutive patients from the same center. Results: Of 1,438 patients in the study cohort, 142 (9.9%) were considered unsuitable for early discharge. C-reactive protein level, body temperature, pulse rate, and neutrophil count had good performance metrics and were determined to be independent prognostic factors. An algorithm consisting of these 4 parameters had a negative predictive value (NPV) of 95.9% (95% confidence interval [CI], 94.2-97.3), sensitivity of 80.3% (95% CI, 72.8-86.5), and specificity of 51.1% (95% CI, 48.3-53.8). Only 28 (1.9%) patients in the study cohort were classified as false negatives. In the validation dataset, the NPV was 93.7%, sensitivity was 66%, and 3.3% (17/512) of patients were classified as false negatives. Conclusions: Simple clinical and laboratory parameters obtained on the third POD can be used when making decisions regarding the safe early discharge of patients who underwent gastrectomy.

• 한국의학물리학회지:의학물리
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• 제10권1호
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• pp.17-22
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• 1999

임상에서 사용되는 가속기의 설계특성변화가 빔 출력변화에 미치는 영향을 알아봄으로써 보다 효율적인 정도관리를 수행하고자 한다. 선형가속기를 구성하고 있는 여러 가지 요소 중에서 빔 조정 인자들인 이온원부의 입사전류 (INJ-I), 이온원부의 입사전압 (INJ-E), 가속전압 (PFN), 휨자석 전류 (BMI), 펄스반복주파수 (PRF)를 선택하여 디지털 메바트론 제어프로그램 상에서 선형가속기가 자동 제어되는 허용범위를 조사한 후 그 영역내에서 전류값들을 변화시켜가면서 선량에 어떠한 영향을 미치는지 알아보았다. 이온함을 사용하여 홉수선량을 측정하고 오실로스코프를 사용하여 빔 출력의 파형을 분석하였으며 방사선 계측장치로 대칭성과 평평도를 계측하였다. 방사선 가속 장치는 선형가속기 (Mevatron MD, Siemens, Germany)를 이용하였으며, 계측장치로는 RFAplus (Scanditronix, Sweden)를 사용하였다. 그리고 가속기의 설계특성변화 즉 , 빔 조정 인자들의 변화가 선량분포특성에 변화를 주는 것을 측정하기 위해 0.6cc 이온함(Capintec PR06C, USA), 미소전위계(Capintec192, USA)와 오실로스코프 (Tektronix, USA)를 사용하였다. 선형가속기의 선량률과 에너지변화에 영향을 미치는 인자들인 INJ-I, INJ-E, PFN, BMI, PRF의 전압과 전류값들을 변화시켰을 때 인자들마다 차이는 있었지만, 이온함을 사용하여 측정했을 때와 오실로스코프로 출력펄스의 변화를 보았을 때는 선량률의 변화를 확인할 수 있었다. 그러나 RFAplus로 에너지와 대칭성 등에 관한 그래프를 그렸을 때는 거의 동일한 결과를 나타내었다. 인자 INJ-I, INJ-E, PFN, BMI, PRF 들의 D10/D20은 0∼0.02, 대칭성은 0.1-0.2%, 평평도는 0.1∼0.4%의 미세한 변화를 보였다. 디지털화 된 각 인자들의 전류와 전압값들을 변화시킬 때 선량률에는 미세한 영향을 미치게 되지만, 기계자체에서 기준값에 맞추기 위해 자동 제어가 되어 선량분포에는 크게 영향을 미치지는 못하는 것으로 평가되어졌으나 빔 조정 인자들의 특성을 파악함으로써 정도관리의 기초자료를 확보하였다.

• 한국진공학회지
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• 제18권1호
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• pp.54-59
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• 2009

3전극 면방전형 AC-PDP에서 발광효율을 높이기 위한 방법으로 새로운 구조의 ITO전극을 제안하였다. 기존에 사용하고 있는 사각형(square), T 형태의 ITO 전극구조와 새롭게 설계한 물고기뼈 형태(fish-boned type) ITO 전극 구조의 시험패널을 제작하였다. 레이저 흡수 분광법(Laser absorption spectroscopy)을 이용하여 각 ITO 전극 구조에 따라 Xe 여기종의 밀도분포를 측정하고, 고속 ICCD(Image Intensified Charge-Coupled Diode) 카메라를 이용하여 각각의 전극에 따른 $750\;nm\;{\sim}\;900\;nm$ 파장의 방전모습을 확인하였다. 시험패널 상판의 x, f 전극에 220V의 사각펄스(square pulse)를 교대로 인가하여 방전시켰다. 사각형, T 그리고 물고기뼈 형태의 ITO 전극 구조에서 $X_e$ 여기종 밀도는 각각 $2.06{\times}10^{13}\;cm^{-3}$, $2.66{\times}10^{-3}\;cm^{-3}$와 $3.01{\times}10^{13}\;cm^{-3}$으로 물고기뼈 형태에서 가장 높게 측정되었다.

• The Korean Journal of Physiology
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• 제26권2호
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• pp.113-122
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• 1992

It is well known that chromaffin cells of adrenal medulla secrete catecholamine in response to sympathetic nerve activation and the influx of $Ca^{2+}$ through the voltage dependent $Ca^{2+}$ channels (VDCC) in the cell membrane do a major role in this secretory process. In this study, we explored the effect of divalent cations on VDCC of rat chromaffin cells. Rat (Sprague-Dawley rat, 150-250 gm) chromaffin cells were isolated and cultured. Standard giga seal, whole cell recording techniques were employed to study $Ca^{2+}$ current with external and internal solutions that could effectively isolate VDCC currents $(NMG\;in\;external\;and\;TEA\;and\;Cs^{2+}\;in\;internal\;solution)$. The voltage dependence and the inactivation time course of VDCC in our cells were identical to those of bovine chromaffin cells. A persistent inward current was first activated by depolarizing step pulse from the holding potential (H.P.) of -80 mV to -40 mV, increased to maximum amplitude at around +10 mV, and became smaller with progressively higher depolarizing pulses to reverse at around +60 mV. The inactivation time constant $(\tau)$, fitted from the long duration test potential (2 sec) was $1295.2{\pm}126.8$ msec $(n=20,\;1\;day\;of\;culture,\;mean\;{\pm}S.E.M.)$ and the kinetic parameters were not altered along the culture duration. Nicardipine $(10\;{\mu}M)$ blocked the current almost completely. Among treated divalent cations such as $Cd^{2+},\;Co^{2+},\;Ni^{2+},\;Zn^{2+}\;and\;,Mn^{2+},\;Cd^{2+}$ was the most potent blocker on VDCC. When the depolarizing step pulse from -80 mV to 10 mV was applied, the equilibrium dissociation constant $(K_d)$ of $Cd^{2+}\;was\;39\;{\mu}M,\;K_d\;of\;Co^{2+}\;was\;100\;{\mu}M\;and\;K_d\;of\;Ni^{2+}];was];780{\mu}M.$ The principal findings of this study are as follows. First, the majority of $Ca^{2+}$ channels in rat chromaffin cells are well classified to L-type $Ca^{2+}$ channel in the view of kinetics and pharmacology. Second, all divalent cations tested could block the $Ca^{2+}$ current and the most potent blocker among the tested was $Cd^{2+}$.

• The Korean Journal of Physiology
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• 제4권2호
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• pp.5-17
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• 1970

The effects of Physical exercise, gymnastics and sports on the cardiopulmonary function were studied in the middle and high school toys. The subjects were divided into 4 groups; non-training group and training group in both middle school and high school boys. In the above groups, pulmonary function studies were performed, and blood pressure and the heart rate were also checked to evaluate physical fitness during and immediately after running exercise on the tread-mill, with the speed of 5 MPH and elevation of 9% and 11.25%. The types of sports in the training group were base ball, body building, Taekwondo (Korean style boxing) and hand ball. The results obtained were as followings: 1) In the training group, cardiopulmonary function showed some tendency of the increase comparing to the non-training group. 2) The increase in cardiopulmonary function was observed according to the age became older, but the clear changes on cardiopulmonary function was not observed as the difference of the group between the training and the non-training. 3) The expiratory volume was decreased as the increase of age except 17 years of age for the value of the per kg body weight. 4) In the non-training group, the mean value of oxygen consumption under maximum work load was increased, while those in the training group was decreased. But it may be noted that oxygen consumption for the expiratory volume was increased in the training group, and that the oxygen cost in the training group was .higher than that of the non-training group. 5) The pulse pressure of the high school group during and immediately after running exercise was observed in the higher value comparing with that of the middle school group It was suggested that the changes of the pulse pressure was owing to the method of determination and that to the decrease of diastolic pressure caused by the decrease of peripheral vascular resistance up to critical closing pressure. 6) Any differences of the changes in the heart rate between the training group and non-training group was not observed during and immediately after running exercise. 7) The relative value of the expiratory volume to the heart rate was decreased in the elder age group.

• 한국해안해양공학회지
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• 제7권3호
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• pp.265-276
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• 1995

본 논문에서는 실시간 해황예보 시스템 개발의 일환으로 수행된 회선적분법을 이용한 신속 표층유속 재현에 대하여 다룬다. 바람응력은 공간적으로 균일하고 대 기압은 무시된다. Data Base 구축을 위하여 4방향의 바람(북서, 북동, 남서, 남동)을 고려하여 각 지점의 회선적분의 가중치를 Galerkin-FEM 모형에 의해 계산하였다. 시간에 따른 바람응력이 주어지면 구성된 Data Base를 이용하여 회선적분법에 의해 신속한 예보가 가능하다. 시간적으로 변하는 임의의 바람응력은 6시간 단위로 정의되는 wind pulse의 연속으로 표현되며 총 12개의 pulse(즉, 72시간전)가 convolution product에 사용된다. 회선적분법의 적용 가능성을 확인하기 위하여 황해 이상화한 해역과 황해와 동지나해에 이르는 실제 해역에서의 수치실험이 수행되었다. 고려한 바람응력은 역풍류 생성 확인을 위하여 시간에 따라 sin 함수적으로 변하는 북풍을 고려하였고, 실험 결과 역풍류 생성의 화인과 회선적분법을 이용한 신속 표층해류 예측 가능성을 확인할 수 있었다.

• The Korean Journal of Physiology
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• 제23권2호
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• pp.313-328
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• 1989

The electrophysiological properties of the inward current contributing to the late plateau phase of the action potential were investigated using the whole cell clamp technique and intracellular dialysis in single atrial cells isolated from the rabbit heart. The inward current was activated by various repolarizing pulses after a brief depolarizing pulse to +40 mV for 2 ms and its time course was similar to that of the late plateau of the action potential. The current was fully activated above the potential of -40 mV and abolished by intracellular EGTA. Ryanodine of $1{\mu}M$ also abolished the late plateau and the inward current. Reduced $Na_o\;to\;30%\;and\;20\;mM\;Na_1$ diminished the late plateau together with the inward current. Diltiazem blocked the activation of the current and Ni in the concentration of $40{\sim}200\;{\mu}M$ decreased the development of the late plateau and the inward current. Fully activated current-voltage relation of the inward current showed exponential voltage dependency which was steeper in more hyperplarizing range. The above findings suggest that the inward current was activated by intracellular calcium and contribute the late plateau phase of the action potential. It could be concluded that the inward current would be the inward component of Na-Ca exchange.