• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.300-300
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• 1994

$Na^{+}$,$K^{+}$-ATPase activity, $Na^{+}$-dependent phosphorylalion, and [$^3$〕ouabain binding in sarcolemma prepared from 4 week old spontaneously hypertensive rat(SHR) ventricles were compared to the same parameters in sarcolemma from age matched normotensive Wistar-Kyoto(WKY) rat ventricles to examine whether the reduced myocardial $Na^{+}$-pump activity in SHR is an inherited enzymatic defect or a second phenomenon due to sustained hypertension. The total body weights, ventricular weights, and blood pressures were the same for SHR and WKY. No significant differences in sarcolemmal protein content and protein recovery were noted between the two pups. Sarcolemma isolated from SHR ventricles showed sigificantly less $Na^{+}$,$K^{+}$-ATPase activity and number of phosphorylation sites when compared to snrcolemma 1mm the WKY ventricles. Equilibrium binding of [$^3H$〕ouabain and the turnovcr number of myocardial $Na^{+}$,$K^{+}$-ATPast however, wee the same for both groups. These results. indicate that the low affinity(${\alpha}$, or ${\alpha}_1$) isoform for ouabain is reduced in SHR compared to WKY but that the high affinity(${\alpha}$+, or ${\alpha}_2$) isoform is the same in ventricles of SHR and WKY. The reduced amount of at isoform of the $Na^{+}$,$K^{+}$-ATPasc in prehypertensive SHR ventricles may play some pole in the development of hypertension.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.272-275
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• 1999

Generally, it is known that the composition of the cation of the dog's RBCs is high in potassium(K) and low in sodium(Na). However, it is reported that certain kinds of dogs have HK, HG phenotype which contains a large amount of reduced glutathione(GSH) by the effect of Na-K pump on the cell membrane of RBC with high concentration of K and low concentration of Na. Although this HK phenotype is not regarded as a disease, it is supposed to be an important assignment to examine the distribution and the occurrence rate of the dogs that contain HK cell in their RBCs for the proper clinical treatments as these HK dogs are very sensitive to aromatic disul-fide or onions and have a tendency to cause hemolysis. Accordingly, present study was performed to measure the concentration of K, Na and GSH in the RBCs of Jindo dogs and that of Dosa dogs at the same time.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.19-19
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• 2003

We have developed a cardiac cell model (Kyoto Model) for the sinoatrial node and ventricle, which is composed of a common set of kinetic equations of membrane ionic currents, Ca$\^$2+/dynamics of sarcoplasmic reticulum and contractile protein. To expand this model by including metabolic pathways, the intracellular ATP metabolism, which is pivotal in cardiac excitation - contraction coupling, was incorporated. ATP consumption by the sarcolemmal Na$\^$+/ pump and the Ca pump in the sarcoplasmic reticulum were calculated with stoichiometry of 3Na:2K:1ATP and 2Ca:1ATP, respectively. ATP consumption by contraction was estimated according to experimental data. Dependence of contraction on ATP and inorganic phosphate was modeled, based on data of skinned cardiac fiber. in production by mitochondrial oxidative phosphorylation was modified from Korzeniewski '||'&'||' Zoladz (2001), and creatine kinase and adenylate kinase reactions were incorporated. ATP dependence of ATP-sensitive K channel and L type Ca channel were also included.

• Journal of Soil and Groundwater Environment
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• v.14 no.4
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• pp.10-14
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• 2009

Objective of this study was to examine the effects of grouts and temperature change on microorganisms in geothermal heat pump. Groundwater samples were obtained from wells in the heat pump system during installation (Oriental medicine hospital) and in the heat pump system under operation (Business incubation center). Grouts are the volclay sodium bentonite. Real-time PCR was used to evaluate total bacterial number and 16S rDNA. The results showed that total bacterial number of groundwater in the heat pump operation was greater than that of non-operation case, which indicates a temperature effect on the bacterial culture. In addition, high concentration of grout showed an elevated bacteria number. In the mean time, a long-term field monitoring is essentially required to confirm the effects of the grouts and the temperature changes.

• The Journal of Internal Korean Medicine
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• v.18 no.2
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• pp.220-228
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• 1997

Background The stenosis of the coronary artery may decrease myocardial oxygen supply and occur myocardial ischemia or infarction. Soojeomsan, one of analgesics is generally regarded to have the effect of vitalizing blood, expelling blood stasis and alleviation cardiac pain. Methods The purpose of this experimental study is to find the influence of Soojeomsan on cardiac enzyme (CPK, Na-K ATPase) of ischemic and reperfused rat hearts which are isolated under the Langendorff apparatus. Ischemia was induced In isolated hearts of Sprague-Dawley rats by ceasing the perfusion for 20 minutes. The experiments were divided into a normal saline orally administered group(control group), a Soojeomsan orally 20ml administered group(sample A) and a Soojeomsan orally 30ml administered group(sample B). The CPK (creatinine phosphokinase) and Na-K ATPase activity of this three group were measured and compared in order to assess the influence of Soojeomsan on protection of isolated rat hearts from ischemia. Results 1. CPK was significantly reduced in Sample A group and Sample B group in comparison with control group in reperfusion(P<0.01), and there were no significant difference between Sample A and B. 2. Na-K ATPase activity was significantly increased in Sample A group and Sample B group in comparison with control group in ischemia(P<0.001), and the activity was significantly higher in Sample B then in Sample A.(P<0.01) 3. There were no significant difference in Na-K ATPase activity of the three groups after reperfusion. Conclusion Soojeomsan has effects to decrease CPK activity and activate Na pump. This result in protection of the myocardium of isolated rat hearts from ischemia.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.2
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• pp.100-106
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• 2018

Recently, the development of a heat pump technology to recover process waste heat and to generate steam of $120^{\circ}C$ or higher required for industrial processes, has attracted attention. The research of conventional heat pump utilizing the available energy is used primarily for air conditioning, and the production temperature is about $60^{\circ}C$, so it is difficult to utilize it for industrial use. Therefore, in this study, we developed a steam heat pump (SGHP) which recovers the waste heat of process and generates steam at $120^{\circ}C$. The low-pressure refrigerant R245fa, considered to be an eco-friendly refrigerant, has been selected as the refrigerant for SGHP in this study since its Ozone Depletion Potential (ODP) is zero and the Global Warming Potential (GWP) is relatively low. A flash tank functioning as a phase separator was installed in the rear stage of the condenser, and the saturated water of high temperature was decompressed to generate steam. It was started at the initial temperature of $70^{\circ}C$, and it was confirmed that $120^{\circ}C$ steam was produced after the system stabilized. We have conducted experiments by modifying the system, and ultimately achieved a heating capacity of 101.4 kW and a COP of 3.05.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1080-1086
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• 2005

Membranes prepared from Vibrio natriegens oxidized both NADH and deamino-NADH as substrates. The maximum activity of the membrane-bound NADH oxidase was obtained at about pH 8.5 in the presence of 0.2 M NaCl, whereas that of the NADH:ubiquinone oxidoreductase was obtained at about pH 7.5 in the presence of 0.2 M NaCl. Electron transfer from NADH or deamino-NADH to ubiquinone-l or oxygen generated a considerable membrane potential (${\Delta}{\psi}$), which occurred even in the presence of $20{\mu}M$ carbonylcyanide m-chlorophenylhydrazone (CCCP). However, the ${\Delta}{\psi}$ was completely collapsed by the combined addition of $10{\mu}M$ CCCP and $20{\mu}M$ monensin. On the other hand, the activity of the NADH oxidase and the ${\Delta}{\psi}$ generated by the NADH oxidase system were inhibited by about $90\%$ with $10{\mu}M$ HQNO, whereas the activity of the NADH:ubiquinone oxidoreductase and the ${\Delta}{\psi}$ generated at the NADH:ubiquinone oxidoreductase segment were inhibited by about $60\%$. Interestingly, the activity of the NADH:ubiquinone oxidoreductase and the ${\Delta}{\psi}$ generated at the NADH:ubiquinone oxidoreductase segment were resistant to the respiratory chain inhibitors such as rotenone, capsaicin, and $AgNO_3$, and the activity of the NADH oxidase and the ${\Delta}{\psi}$ generated by the NADH oxidase system were very sensitive only to $AgNO_3$. It was concluded, therefore, that V. natriegens cells possess a $AgNO_3$-resistant respiratory $Na^+$ pump that is different from the $AgNO_3$-sensitive respiratory $Na^+$ pump of a marine bacterium, Vibrio alginolyticus.

• The Korean Journal of Physiology
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• v.29 no.2
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• pp.203-216
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• 1995

The effects of ${\alpha}_1-adrenergic$ receptor stimulation on membrane potential, intracellular $Na^+$ activity, and twitch force were investigated in ventricular muscles from guinea-pig hearts. Action potentials, intracellular $Na^+$ activity, and twitch force of ventricular papillary muscles were measured simultaneously under various experimental conditions. Stimulation of the ${\alpha}_1-adrenergic$ receptor by phenylephrine produced variable changes in action potential duration, a slight hyperpolarization of the diastolic membrane potential, a decrease in intracellular $Na^+$ activity, and a biphasic inotropic response in which a transient negative inotropic response was followed by a sustained positive inotropic response. These changes were blocked by prazosin, an antagonist of the ${\alpha}_1-adrenergic$ receptor, but not by atenolol, an antagonist of the ${\beta}-adrenergic$ receptor. This indicates that the changes in membrane potential, intracellular $Na^+$ activity, and twitch force are mediated by stimulation of the ${\alpha}_1-adrenergic$ receptor, but not by stimulation of ${\beta}-adrenergic$ receptor. The decrease in intracellular $Na^+$ activity was not observed in quiescent muscles, depending on the rate of the action pontentials in beating muscles. The intracellular $Na^+$ activity decrease was substantially inhibited by tetrodotoxin. However, the decrease in intracellular $Na^+$ activity was not affected by an inhibition of the $Na^+-K^+$ pump. Therefore, the decrease in intracellular $Na^+$ activity mediated by the ${\alpha}_1-adrenergic$ receptor appears to be due to a reduction of $Na^+$ influx during the action potential, perhaps through tetrodotoxin sensitive $Na^+$ channels. Our study also revealed that the decrease in intracellular $Na^+$ activity might be related to the transient negative inotropic response. The intracellular $Na^+$ activity decrease could lower intracellular $Ca^{2+}$ through the $Na^+-Ca^{2+}$ exchanger and thereby produce a decline in twitch force.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.5
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• pp.199-205
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• 2014

The integration of FC (Fuel Cell) and GSHP (Ground Source Heat Pump) hybrid system could produce a synergistic advantage in thermal and electric way. This study intends to analyse the economical aspect of a FC integrated GSHP hybrid system compared to the conventional system which is consisted with a boiler and a chiller. Based on the hourly simulation, the study indicated that GSHP system and FC+GSHP hybrid system could reduce the energy consumption on a building. The method of the economic assessment has been based on IEA ECBCS Annex 54 Subtask C SPB(Simple Payback) method. The SPB was calculated using the economic balanced year of the alternative system over the conventional (reference) system. The SPB of the alternative systems (GSHP and FC+GSHP) with 50% initial incentive was 4.06 and 26.73 year respectively while the SPB without initial incentive of systems was 10.71 and 57.76 year.

• Journal of Drive and Control
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• v.21 no.2
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• pp.1-7
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• 2024

This paper proposes a novel cooling system for hydrogen fuel cell cooling systems by integrating heat pump technology to enhance operational efficiency. The study analyzed the cooling efficiency of the fuel cell cooling system. With the increasing focus on eco-friendly vehicle technologies to address environmental concerns and global warming, the transportation sector, a major contributor to greenhouse gas emissions, needs technological enhancements for better efficiency. The proposed cooling system was modeled through 1-D simulations. The analysis results of parameters such as thermal balance, temperature, and pressure of each component confirmed the stable operation of the system. By examining variations in the cooling system's flow rate, compressor RPM, and the Coefficient of Performance (COP) based on different refrigerants, initial research was conducted to derive optimal operating conditions and parameter values.