• Journal of Society of Preventive Korean Medicine
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• v.14 no.2
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• pp.105-120
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• 2010

Objectives : This study aims to evaluate the effects of expiration-to-inspiration time ratio (E/I-ratio) on heart rate, which represents cardiac autonomic function, and cold-heat in the healthy people. Methods : 49 healthy young volunteers(male : female = 32 : 17) were recruited in the study. The participants completed the questionnaire for yin-yang pattern identification and then we measured the chest plethysmogram for respiration signal and the electrocardiogram for NN intervals during different E/I-ratio from 1 to 2. We compared heart rate variability including RMS-SD, VLF, LF and HF, and the trend-cycle factors decomposed from NN interval data by time series analysis among the respective E/I-ratio. We also confirmed the difference on the trend-cycle factors according to the score of the questionnaire for cold and heat pattern identification. Results : There were differences on the trend-cycle factors from NN interval data, but no significant difference on heart rate variability, among the respective E/I-ratio. We also found significant relationship between the trend-cycle factors and the heat pattern identification scores. Conclusions : The results indicate that cardiac autonomic function can be modulated by the E/I-ratio and the modulation will be slower and more tendencious than respiratory sinus arrhythmia.

• Biomolecules & Therapeutics
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• v.25 no.5
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• pp.471-481
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• 2017

The canonical transient receptor potential channels (TRPCs) constitute a series of nonselective cation channels with variable degrees of $Ca^{2+}$ selectivity. TRPCs consist of seven mammalian members, TRPC1, TRPC2, TRPC3, TRPC4, TRPC5, TRPC6, and TRPC7, which are further divided into four subtypes, TRPC1, TRPC2, TRPC4/5, and TRPC3/6/7. These channels take charge of various essential cell functions such as contraction, relaxation, proliferation, and dysfunction. This review, organized into seven main sections, will provide an overview of current knowledge about the underlying pathogenesis of TRPCs in cardio/cerebro-vascular diseases, including hypertension, pulmonary arterial hypertension, cardiac hypertrophy, atherosclerosis, arrhythmia, and cerebrovascular ischemia reperfusion injury. Collectively, TRPCs could become a group of drug targets with important physiological functions for the therapy of human cardio/cerebro-vascular diseases.

• Childhood Kidney Diseases
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• v.15 no.1
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• pp.14-21
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• 2011

Although left Left ventricular hypertrophy (LVH) is not only an adaptive response of the heart to increased cardiac workload in hypertension, it surelybut also is the most potent risk factor of overt cardiovascular complications such as coronary heart disease, heart failure, arrhythmia and stroke in the hypertensive population. Also it has become generally accepted that subclinical cardiovascular disease begins in childhood and LVH is the most readily assessed marker for that. As LVH can be seen in children and adolescents with even mild blood pressure elevation with the reported prevalence of 10 to 47%, aggressive antihypertensive treatment is critical in preventing the development of hypertensive heart disease in that those cases.

• Journal of Chest Surgery
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• v.28 no.5
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• pp.437-442
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• 1995

We developed an experimental model of brain death using dogs. Brain death was caused by increasing the intracranial pressure[ICP suddenly by injecting saline to an epidural Foley catheter in five female mongrel dogs[weight, 20-25Kg .Hemodynamic and electrocardiographic changes were evaluated continuously during the process of brain death. 1. Abrupt rise of ICP after each injection of saline followed by a rapid decline to a new steady-state level within 15 minutes and the average volume required to induce brain death was 7.6$\pm$0.8ml.2. Body temperature, heart rate, mean pulmonary arterial pressure, left ventricular[LV enddiastolic pressure and cardiac output was not changed significantly during the process of brain death, but there was an increasing tendency.3. Mean arterial pressure and LV maximum +dP/dt increased significantly at the time of brain death.4. Hemodynamic collapse was developed within 140 minutes after brain death.5. Marked sinus bradycardia followed by junctional rhythm was seen in two dogs and frequent VPB`s with ventricular tachycardia was observed in one dog at the time of brain death. Hyperdynamic state develops and arrhythmia appears frequently at the time of brain death. Studies on the effects of brain death on myocardium and its pathophysiologic mechanism should be followed in the near future.

• The Journal of Korea Robotics Society
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• v.15 no.4
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• pp.301-308
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• 2020

In this paper, we deal with the static modeling of a continuum robot that can perform surgical interventions. The proposed continuum robot is made of stainless steel wires and a multi lumen flexible tube using a thermoplastic elastomer. This continuum robot could be most severely deformed in physical contact with narrow external environments, when a lateral external force acts at the distal tip of the continuum robot. In order to predict the shape and displacement under the lateral external force loading, the forward kinematics, the statics modeling, the force-moment equilibrium equation, and the virtual work-energy method of the continuum robot are described. The deflection displacements were calculated using the virtual work-energy method, and the results were compared with the displacement obtained by the conventional cantilever beam theories. In conclusion, the proposed static modeling and the virtual work-energy method can be used in arrhythmia procedure simulations.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.275-278
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• 1997

Standard methods estimating the power spectral density(PSD) from an irregularly sampled cardiac event series require deriving a new evenly-spaced signal applicable to those methods. To avoid that requirement, in this study, the power spectrum of heart rate variability was estimated by Lomb-Scargle's algorithm, which is a means of obtaining PSD estimates directly from irregularly sampled timeseries observed in astronomy. To assess the performance of Lomb-Scargle algorithm in the power spectral analysis of heart rate variability, it was applied to various cardiac event series derived through integral pulse frequency modulation model(IPFM) simulation and from real ECG signals, and the resultant power spectra was compared with those obtained by a conventional method based on the FFT. In result, it is concluded that Lomb-Scargle's periodogram is very effective in the power spectral analysis of heart rate variability, especially in the presence of arrhythmia and/or dropouts of cardiac events.

• YAKHAK HOEJI
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• v.57 no.3
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• pp.161-166
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• 2013

Sinomenium acutum has been used for the treatment of rheumatoid arthritis, arrhythmia, and pain. We evaluated the quality of S. acutum extract by quantitatively analyzing its components such as sinomenine, magnoflorine and syringaresinol with the simultaneous determination method using HPLC-DAD. A total of 53 samples collected from different localities were evaluated with this quality evaluation method. Sinomenine, magnoflorine and syringaresinol from tested samples ranged from 0.0649~9.1050%, 0.7460~10.7590% and 0.0010~0.2441%, respectively. In the current study, we were able to exhibit the diverse quality of S. acutum samples collected from various locations using the simultaneous determination method.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.352-362
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• 1999

Thiopental sodium is known as ultrashort-acting barbiturates and can be employed advantageously for numerous conditions. But thiopental has the side effects of cardiovascular and respiratory systems which has barbiturates and are depend on the dose of thiopental. The side effects are reduced when the thiopental is preceded by a tranquilizer and sedative. In these drugs, benzodiazepines have the minimal effects of cardiovascular and respiratory systems. In this study, the effects of midazolam preanesthetic administration, followed by thiopental anesthetic induction, on cardiovascular system and thiopental induction requirement were studied in 14 mixed breed dogs. Cardiovascular data were recorded baseline, after premedication of saline 0.45 ml/kg or midazolam 0.1, 0.2, 0.4, 0.8 mg/kg, intubation, and 5, 10, 15, 20, 30 minutes after intubation. Extubation, head-up, sternal recombency, standing, and walking recovery times were recorded. The results were summarized as follows; (1) The 0.1, 0.2, 0.4, and 0.8 mg/kg dosages of midazolam insignificantly decreased thiopental dose requirement necessary to accomplish intubation by 6, 20, 21 and 28%. (2) The 0.1, 0.2, 0.4, and 0.8 mg/kg dosages of midazolam insignificantly reduced the times of extubation, head-up, sternal recumbency, standing, and walking recovery. (3) Midazolam was effective in reducing the frequency and duration of arrhythmia after intubation. (4) Heart rates of preanestheic midazolam administraion groups increased after thiopental injection which insignificantly changed smaller than those of control group. (5) Arterial blood pressures did not vary significantly among groups.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.128-132
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• 2011

Holter monitoring has been recognized as an useful noninvasive instrument for monitoring the cardiac electrical activity over 24 to 48 hours. Because the surface electrocardiogram (ECG) is recorded only for several seconds to minutes, it often misses or underestimates the underlying arrhythmia. The surface ECG is also easily influenced by depolarization potentials from skeletal muscle by the movement of patient (especially muscle tremor). However, holter monitoring is less affected by such factors. There has been no precedential report in veterinary medicine applying digital holter monitor with unipolar precordial chest lead using 4 electrodes. This article describes its clinical indications, equipment and technical application method in dogs.

• Journal of Chest Surgery
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• v.28 no.4
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• pp.355-359
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• 1995

A clinical analysis was performed on 48 cases with mitral stenosis who received open mitral commissurotomy from December 1983 to June 1991 at the Department of Thoracic & Cardiovascular Surgery, Chungnam National University Hospital. Fifteen patients were men and 33 were women. the mean age was 35.6 years with the range of 16 to 61 years. The distribution of preoperative NYHA Functional Classes was as follows; class II, 25 patients; class III, 20 patients; class IV, 3 patients. Three patients had cerebral emboli preoperatively, all of whom were in atrial fibrillation. The preoperative electrocardiographic studies revealed that 32 patients had sinus rhythms and 16 had atrial fibrillations. Twenty-six patients had open mitral commissurotomy alone and 22 patients had additional cardiac procedures. Intraoperatively, there were 6 cases of left atrial thrombosis. There was no perioperative death but early postoperative complications were found in 3 cases. The patients were followed up from 2 to 99 months[mean 33.7 months . There was one case of late unexplained sudden death. There was a case of late postoperative cerebral infarction, 5 cases of mitral restenosis and 3 cases of congestive heart failure and/or arrhythmia. Mitral valve replacements were required in 3 patients.But, it is evident that open mitral commissurotomy has many advantages beyond mitral valve replacement concerning the results of the mitral valve replacement underwent during the same period at the Department of Thoracic & Cardiovascular Surgery, Chungnam National University Hospital.