• 대한핵의학회지
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• 제26권2호
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• pp.265-273
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• 1992

Rest gated blood pool scan (Rest GBP scan) and dipyridamole $^{99m}Tc-MIBI$ SPECT were Performed in 34 patients with or suspected coronary artery disease. Both studies were performed within $2\sim32$ days (mean 8.1 days). A significant correlation was present between left ventricular ejection fraction (r= -0.7356, p<0.001) and peak ejection rate and peak filling rate in rest GBP scan and perfusion defect in MIBI SPECT. And there were acceptable correlations (0.05$26.2{\pm}10.8%$, severe hypokinesia, akinesia or dyskinesia in 16 regions: $78.2{\pm}23.7$, p<0.001). These data indicate there is a significant coupling between the degree of myocardial perfusion and the myocardial functional change in coronary artery disease.

• Korean Journal of Radiology
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• 제20권1호
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• pp.83-93
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• 2019

Objective: The purpose of this study was to prospectively investigate the value of the myocardial extracellular volume fraction (ECV) in predicting myocardial functional outcome after revascularization of coronary chronic total occlusion (CTO). Materials and Methods: Thirty patients with CTO underwent cardiovascular magnetic resonance (CMR) before and 6 months after revascularization. Three baseline markers of functional outcome were evaluated in the dysfunctional segments assigned to the CTO vessels: ECV, transmural extent of infarction (TEI), and unenhanced rim thickness (RIM). At the global level, the ECV values of the whole myocardium with and without a hyperenhanced region (global and remote ECV) were respectively measured. Results: In per-segment analysis, ECV was superior to TEI and RIM in predicting functional recovery (area under receiver operating characteristic curve [AUC]: 0.86 vs. 0.75 and 0.73, all p values < 0.010), and it emerged as the only independent predictor of regional functional outcome (odds ratio [OR] = 0.83, 95% confidence interval [CI]: 0.77-0.89; p < 0.001) independent of collateral circulation. In per-patient analysis, global baseline ECV was indicative of ejection fraction (EF) at the follow-up examination (β = -0.61, p < 0.001) and changes in EF (β = -0.57, p = 0.001) in multivariate regression analysis. A patient with global baseline ECV less than 30.0% (AUC, 0.93; sensitivity 94%, specificity 80%) was more likely to demonstrate significant EF improvement (OR: 0.38; 95% CI: 0.17-0.85; p = 0.019). Conclusion: Extracellular volume fraction obtained by CMR may provide incremental value for the prediction of functional recovery both at the segmental and global levels in CTO patients, and may facilitate the identification of patients who can benefit from revascularization.

• Clinical and Experimental Pediatrics
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• 제60권11호
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• pp.365-372
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• 2017

Purpose: The mechanism for the pathogenesis of adriamycin (ADR)-induced cardiomyopathy is not yet known. Different hypotheses include the production of free radicals, an interaction between ADR and nuclear components, and a disruption in cardiac-specific gene expression. Apoptosis has also been proposed as being involved in cardiac dysfunction. The purpose of this study was to determine if apoptosis might play a role in ADR-induced cardiomyopathy. Methods: Male Sprague-Dawley rats were separated into 2 groups: the control group (C group) and the experimental group (ADR 5 mg/wk for 3 weeks through intraperitoneal injections; A group). Echocardiographic images were obtained at week 3. Changes in caspase-3, B-cell leukemia/lymphoma (Bcl)-2, Bcl-2-associated X (Bax), interleukin (IL)-6, tumor necrosis $factor-{\alpha}$, brain natriuretic peptide (BNP), troponin I, collagen 1, and collagen 3 protein expression from the left ventricle tissues of C and A group rats were determined by Western blot. Results: Ascites and heart failure as well as left ventricular hypertrophy were noted in the A group. Ejection fraction and shortening fraction were significantly lower in the A group by echocardiography. The expression of caspase-3, Bax, IL-6, BNP, collagen 1, and collagen 3 were significantly higher in the A group as compared with the C group. Protein expression of Bcl-2 decreased significantly in the A group compared with the C group. Conclusion: ADR induced an upregulation of caspase-3, Bax, IL-6, and collagen, as well as a depression in Bcl-2. Thus, apoptosis and fibrosis may play an important role in ADR-induced cardiomyopathy.

• 천문학회지
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• 제39권4호
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• pp.139-145
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• 2006

We have made a comprehensive statistical study on the coronal mass ejections(CMEs) associated with helmet streamers. A total number of 3810 CMEs observed by SOHO/LASCO coronagraph from 1996 to 2000 have been visually inspected. By comparing their LASCO images and running difference images, we picked out streamer-associated CMEs, which are classified into two sub-groups: Class-A events whose morphological shape seen in the LASCO running difference image is quite similar to that of the pre-existing streamer, and Class-B events whose ejections occurred in a part of the streamer. The former type of CME may be caused by the destabilization of the helmet streamer and the latter type of CME may be related to the eruption of a filament underlying the helmet streamer or narrow CMEs such as streamer puffs. We have examined the distributions of CME speed and acceleration for both classes as well as the correlation between their speed and acceleration. The major results from these investigations are as follows. First, about a quarter of all CMEs are streamer-associated CMEs. Second, their mean speed is 413 km $s^{-1}$ for Class-A events and 371 km $s^{-1}$ for Class-B events. And the fraction of the streamer-associated CMEs decreases with speed. Third, the speed-acceleration diagrams show that there are no correlations between two quantities for both classes and the accelerations are nearly symmetric with respect to zero acceleration line. Fourth, their mean angular width are about $60^{\circ}$, which is similar to that of normal CMEs. Fifth, the fraction of streamer-associated CMEs during the solar minimum is a little larger than that during the solar maximum. Our results show that the kinematic characteristics of streamer-associated CMEs, especially Class-A events, are quite similar to those of quiescent filament-associated CMEs.

• 기본간호학회지
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• 제15권4호
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• pp.485-494
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• 2008

Purpose: In this study, relationships between symptom experience and quality of life in a cross-sectional sample of patients with Atrial Fibrillation (AF) were investigated. Methods: This descriptive study involved a convenience sample of AF patients from S university hospital, C city. One hundred and two AF patients completed psychometric validated measures of AF related symptoms and quality of life. Descriptive statistics and Pearson correlation coefficients with SPSS WIN 14.0 were used for data analysis. Results: Of 16 atrial arrhythmia-related symptoms, the patients reported 'tiredness' as the most frequent and 'shortness of breath' as the most severe. The level of overall quality of life for patients with AF was 53.92. There were significant differences in symptom frequency according to religion, New York Heart Association (NYHA) classification and left ventricular ejection fraction ; symptom severity according to monthly income and stroke ; quality of life according to age, job, alcohol intake, NYHA class and stroke. Quality of life for these patients was positively correlated with symptom frequency and symptom severity. Conclusions: This study demonstrated that patients with more frequent and severe symptoms perceive poorer quality of life than patients with less frequent and less severe symptoms. Symptom experience should be assessed early to improve quality of life for patients.

• Journal of Chest Surgery
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• 제26권4호
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• pp.271-275
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• 1993

In this country, the number of patients with coronary artery disease is progressively increasing with the change of life style and improvement of the diagnostic procedures. In addition, the medically invasive procedure for treating ischemic heart disease was rapidly developed and the surgical patients have more complex and multiple lesions and more surgical risks. Fifty three patients with ischemic heart disease underwent coronary bypass grafting [CABG] for recent 24 months. Twenty patients had three-vessel disease, 17 patients two-vessel disease, and 2 patients single-vessel disease. The average number of distal anastomoses was 3.3 per patient with the range of I to 6 grafts. Forty-one patients [77.4 %] had preoperative left ventricular ejection fraction of 50 % or more and 14 patients[26.4%] had a significant left main coronary lesion. Saphenous vein grafts were employed in 52/53 patients [98.1%] and internal mammary grafts, which were anastomosed to left anterior descending artery, in 38/53 patients[71.7%]. Two patients, whom percutaneous transluminal coronary angioplasty failed for, underwent emergency CABG with only saphenous vein grafts and both patients survived.The hospital mortality was 1.9 % and there was no late death. Perioperative myocardial infarction occurred in 1.9%. All survivors were asymptomatic[in 83% of the patients] and/or improved over their preoperative status. Twenty-nine patients were included in blood conservation group and 21 patients [72.4 %] underwent CABG without any homologous blood transfusion. Our early result of coronary bypass grafting was comparable to that which was reported in other coronary surgery units.

• Journal of Chest Surgery
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• 제32권5호
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• pp.480-483
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• 1999

심폐바이패스와 심정지액을 이용하여 심장을 완전히 정지시킨 상태에서 원위부 관상동맥 문합을 시행하는 방법이 현재 관상동맥우회술에서 널리 사용되고 있다. 하지만, 심정지액을 이용한 심정지하의 관상동맥우회술은, 특히 고위험군 환자에서 수술중 심근의 허혈성 손상을 완전히 배제하지는 못하고 있다. 이런 측면에서 볼 때, 심폐바이패스를 사용치 않는 방법이 관상동맥우회술중 심근의 허혈성 손상을 방지하고 심폐바이패스의 합병증을 줄이기 위한 이상적인 방법이라 할 수 있겠지만, 이는 기술적으로 항상 가능한 것은 아니다. 이에 저자들은 좌심실 구출률이 25%로 좌심실 기능 저하가 심했던 경우와, 경피적 관상동맥확장술 중에 심인성 쇼크가 초래된 경우 등의 고위험군 환자에서 시행한 심폐바이패스하의 심박동상태에서의 관상동맥우회술 2례를 보고하는 바이다

• 한국기계가공학회지
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• 제12권4호
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• pp.22-28
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• 2013

It is important to begin left ventricular assist device (LVAD) treatment at appropriate time for heart failure patients who expect cardiac recovery after the therapy. In order to predict the optimal timing of LVAD implantation, we predicted pumping efficacy of LVAD according to the severity of heart failure theoretically. We used LVAD-implanted cardiovascular system model which consist of 8 Windkessel compartments for the simulation study. The time-varying compliance theory was used to simulate ventricular pumping function in the model. The ventricular systolic dysfunction was implemented by increasing the end-systolic ventricular compliance. Using the mathematical model, we predicted cardiac responses such as left ventricular peak pressure, cardiac output, ejection fraction, and stroke work according to the severity of ventricular systolic dysfunction under the treatments of continuous and pulsatile LVAD. Left ventricular peak pressure, which indicates the ventricular loading condition, decreased maximally at the 1st level heart-failure under pulsatile LVAD therapy and 2nd level heart-failure under continuous LVAD therapy. We conclude that optimal timing for pulsatile LVAD treatment is 1st level heart-failure and for continuous LVAD treatment is 2nd level heart-failure when considering LVAD treatment as "bridge to recovery".

• Journal of Chest Surgery
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• 제17권3호
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• pp.346-355
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• 1984

77 cases of Aortic Valve Replacement, which were composed of 64 rheumatic valvular heart disease and 13 combined congenital heart disease, were operated at Seoul National University Hospital for Aortic valvular disease during the period from June 1968 to December 1983. Among these 64 rheumatic aortic valvular heart disease cases, 8 patients were expired during and immediate after operation and overall mortality rate was 12.5%. For more precise remarks, these patients were divided into two periodic groups, 1st period [from 1968 to 1976] and 2nd [from 1977 to 1983] when annual open heart surgery were over 100 cases, and in 1st period three of four patients were died and in 2nd period five of sixty patients were died and its mortality rate was 8.3%. There were 12 cases of postoperative complication, which were 3 cases of remaining other valvular heart disease required MVR, 2 paravalvular leaks [one of them got Redo AVR], 4 thromboembolism or problem of anticoagulant therapy, 2 late death due to SBE with replaced valve failure and one functional AS with small sized valve. Operative death was affected by pump-time and aortic cross-clamping time, heart size, Ejection Fraction, LVEDP and symptom duration, and other many factors may influence the survival rate. Improved operative technique and myocardial protection and meticulous evaluation of the preoperative patient status will make the AVR safer.

• 한국안전학회지
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• 제27권5호
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• pp.35-41
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• 2012

The Numerical simulation was performed on the flow field around the two-dimensional rectangular bluff body in order to complement the previous experimental results of the bluff body stabilized flames [1]. For both fuel ejection configurations against an oxidizer stream, the flame stability was affected mainly by vortex structure and mixing field near bluff body. FDS(Fire Dynamic Simulator) based on the LES(Large Eddy Simulation) was employed to clarify the isothermal mixing characteristic and wake flow pattern around bluff body. The air used atmosphere and the fuel used methane. The result of counter flow configuration shows that the flow field depends on air velocity but the mixing field is influenced on the fuel velocity. At low fuel velocity the fuel mole fraction is below the flammable limit and hence the mixing is insufficient to react. Therefore, as the result, the flame formed at low fuel velocity is characterized by non-premixed flames. For the flow field of co-flow configuration, flame stability was affected by fuel velocity as well as air velocity. the vortex generated by fuel stream has counter rotating direction against the air stream. Therefore, the momentum ratio between air and fuel stream was important to decide the flame blow out limit, which is result in the characteristic of the partially premixed reacting wake near extinction.