• Journal of Chest Surgery
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• v.35 no.11
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• pp.831-834
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• 2002

When any part of the pacemaker system is infected, all pacemaker hardware should be removed, because reinfection rates of 51% to 77% have been noted in patients whose infected pacemaker system has been only partially explanted. The removal of infected leads during cardiopulmonary bypass prevents mechanical injury as well as the spread of infection and vegetation. We report one case of endocarditis by staphylococcus aureus with infected transvenous pacing lead which was migrated into the heart from the left subclavian vein. We removed the migrated pacing lead and vegetation under cardiopulmonary bypass.

• Journal of Chest Surgery
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• v.12 no.3
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• pp.297-305
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• 1979

Occlusive coronary artery disease presents a potential threat to a significant population in the United States. According to many case reports, the increasing incidence of coronary artery disease due to atherosclerosis is noted in Korean, recently. Operative vascular procedures have increased steadily in number over the past 20 years in the United States. There have been many isolated case reports about coronary artery surgery, but these had little clinical impact. Nowadays, major three coronary bypass surgery has developed principally at three cardiac centers in the United States since 1967. Among three coronary bypass operation, the aorta-coronary artery saphenous vein bypass graft was first demonstrated by Favolaro and Effler at the Cleveland Clinic in 1967. We experienced one case of coronary artery disease, which was treated successfully by aorta-coronary saphenous vein graft with mild hypothermia under extracorporeal circulation in May, 1977. Saphenous vein was removed from above the knee and was 2.5 mm in diameter. The left ventricle was not vented for the left ventricle was not overdistended. Temporary artificial pace-maker-Medtronic-was implanted for the prevention and treatment of post-operative arrhythmia and heart block in post-operative first day. He is a 57 year old male businessman who had been suffered from hypertension [200 mmHg in systolic pressure] since 4 years ago, who had intermittent conservative treatment at local clinic. He had been afflicted with severe chest pain with choking sensation for 50 days. This symptom was aggravated exposing cold weather, or cold water, but was respond to rest. Pre-operative ECG revealed no any other ischemic sign except sinus bradycardia. Significant S-T segment depression was noted at lead II, AVF after double 5 minutes exercise, indicating positive Master`s test. Serum cholesterol was slight elevated to 253 mg/dl. Final pre-operative diagnosis was made by coronary arteriogram, which showed about 1.0-cm segmental 90 % occlusive atherosclerotic lesion in the proximal part of right coronary artery above the origin of acute marginal artery. Left coronary artery revealed good patency and there was no collateral circulation between right and left coronary artery .Hospital course was not eventful. He was discharged with good result on the post-operative day. He has been free from chest pain for longer than 2 years. And also the arterial flow in the coronary bypass graft is auscultated with the pocket-sized ultrasonic velocity detector, which shows the patency of the coronary bypass graft good.

• Fashion & Textile Research Journal
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• v.2 no.5
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• pp.416-422
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• 2000

In this study, to find out the physiological reaction of the human body and the sensation of comfort when people are wearing sportswear which is made of waterproof breathable fabrics under general environmental conditions (temperature : $20{\pm}1^{\circ}C$, humidity : $60{\pm}5%RH$, air current : 0.1 m/sec) and rainy environmental conditions (temperature : $20{\pm}1^{\circ}C$, humidity : $60{\pm}5%RH$, air current : 0.1 m/sec, rainfall : 250 1/hr), we made an experiment with sportswear in an artificial climate chamber and studied the thermal physiological response and subjective sensation. Mean skin temperature of the subjects was low and had a big range of fluctuation in rainy environmental conditions of two condition. Temperature started to increase at the beginning of the exercise, reached the maximum at the 2nd level of the exercise and then started to decline. Rectal temperature showed a slighter increase and bigger range of fluctuation in general conditions than in rainy conditions. Except clothing micro climate in rainy conditions, temperature and humidity and their range of fluctuation around back were higher than those around chest. Humidity was high and had wide range of fluctuation in general conditions. Heart rate was 4.4 beats/min higher in general conditions. In subjective test on rainy conditions, the feeling of discomfort increased due to the raindrops fallen on the skin. Unlike that in general conditions, cold sensation increased and humidity sensation reached to the peak after the exercise. In wearing sportswear made of shape memory breathable waterproof fabric, controlling function over a small amount of heat and water was distinctive while it turned out to be not so comfortable over a large amount of heat and water. Through this, the limitation of shape memory breathable waterproof fabric was recognised.

• Journal of Biomedical Engineering Research
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• v.13 no.3
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• pp.225-234
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• 1992

In order to use a low cost polymer valve in our total artificial heart and ventricular assist device, we have developed a slit-type bileaflet polymer valve[BPV 1. The aim of this study is to determine the hydrodynamic effectiveness of the newly-designed BPV and its feasibility for temporary use in the blood pumps. For hydrodynamic comparison, we investigated in-vitro the pressure drop across the valve, the leakage volume, the flow rate and the flow pattern of the BPV, two mechanical valves and a trileaflet polymer valve. We employed the ventriculo-pulmonary bypassing method for in-vivo tests of the BPV's together vilh our electrohydraulic left venIn ricular assist device in mongrel dogs. The BPV showed adquate gydrodynamic performances and in the preliminary animal bests, there was no xvi dence of thrombus formation on the valve leaflets and around the struts. Detailed results obtained from the animal tests will be separately reported. This report involves the design criteria, fabrication and hydrodynamic charateristics of she BPV, and the basic merits and demerits of the valve are dis- cussed from the hydrodynamic point of view.

• Journal of Chest Surgery
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• v.19 no.1
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• pp.58-67
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• 1986

Aggressive revascularization of the ischemic lower extremities in atherosclerotic, occlusive diseases or acute embolic arterial occlusion due to cardiac valvular disease by thromboembolectomy or an arterial bypass operation has been advocated by some authors. We have performed 68 first time vascular operations, including thromboembolectomies on RR patients with ischemic lower extremities, within an 11-year-and-6-month period, from January 1974 to June 1984. We have reviewed and analyzed our vascular operative procedures and post operative results. The patients upon whom thromboembolectomies were performed were 42 males and 13 females ranging from 5 to 72 years of age. The major arterial occlusive sites were common iliac artery in 20 cases, femoral artery in 21 cases, popliteal artery in 8 cases, common iliac artery and femoral artery in 4 cases, and femoral artery and popliteal artery in 3 cases. The underlying causes of arterial occlusive disease were atherosclerosis obliterans in 34 cases; Buerger`s disease in 3 cases; emboli due to cardiac valvular disease in 13 cases; and vascular trauma in 4 cases, including cardiac catheterization in I of those cases. Arterial bypass operations with autogenous or artificial vascular prosthesis were done in 31 cases. Amputations were done on 2 patients carrying out any more vascular operative procedures would have been of no benefit to them. Our bypass operations for ischemic lower extremities were classified as follows: those done between the abdominal aorta and the femoral artery in 17 cases, including those done between the aorta and the bifemoral arteries with a Y graft in four of those cases and long ones done from the axillary to the femoral artery in 4 cases. Five patients died in the hospital following vascular surgery for ischemic lower extremities, the causes of death were not directly related to the vascular reconstructive operative procedures. The leading causes of death were respiratory failure due to metastatic lung carcinoma: renal failure due to complications from atherosclerosis obliterans; sepsis from open, contaminated fractures of the tibia and fibula; and myocardial failures due to open heart surgery in one case and reconstructive surgery of the ascending aorta in another.

• Journal of Yeungnam Medical Science
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• v.31 no.2
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• pp.113-116
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• 2014

A 52-year-old man was referred to our hospital due to fever and myalgia that occurred 2 weeks earlier. He showed a complete atrioventricular block on his electrocardiogram, and his vital signs were unstable. On his transthoracic echocardiograph, the 1.5 cm vegetation in the aortic valve with severe aortic regurgitation suggested infective endocarditis. His transesophageal enchocardiograph showed abscess in his mitral-aortic intervalvular fibrosa and vegetation was suspected on his anterior mitral valve leaflet. The patient underwent an emergent operation for valve replacement with temporary epicardial pacing. Intraoperatively, the septal leaflet of his tricuspid valve was injured during the debridement of the abscess pocket that was extended to the membranous septum. The aortic, mitral, and tricuspid mechanical valves were replaced with annular reconstruction without complications. After 14 days of intravenous antibiotics, we successfully changed the epicardial pacemaker into a transvenous DDD-type permanent pacemaker by placing a left ventricular lead via the coronary sinus and an atrial lead in the right atrium appendage. The patient was discharged in a tolerable state and was examined uneventfully in our hospital's outpatient clinic for 8 months.

• Journal of the Korea Society of Computer and Information
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• v.15 no.9
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• pp.129-136
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• 2010

With mobile computing, wireless sensor network and sensor technologies, ubiquitous computing services are being realized and could satisfy the feasibility of ubiquitous healthcare to everyone. This u-Healthcare service can improve life quality of human since medical service can be provided to anyone, anytime, and anywhere. To confirm the vision of u-Healthcare service, we've implemented a healthcare system for heart disease patient which is composed of two components. Front-end collects various signals such as temperature, blood pressure, SpO2, and electrocardiogram, etc. As a backend, medical information server accumulates sensing data and performs back-end processing. To simply transfer these sensing values to a medical team may be too trivial. So, we've designed a model based on context awareness for more improved medical service which is based on artificial neural network. Through rigid experiments, we could confirm that the proposed system can provide improved medical service.

• English & American cultural studies
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• v.17 no.1
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• pp.129-162
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• 2017

Ruth Ozeki(Japanese-American female novelist)?s recent novel, A Tale for the Time Being (2013) draws our attention because the fiction shows very interesting fictional experiments, especially in terms of post-humanism. Indeed, the novel is not a science fiction at all which has been, and still is, the typical fictional field employed in the discussion for the transhumanism and posthumanism. It also does not include any cybogs, robots, or aliens which provoke the posthumanism-related issues like mind/body, human/nonhuman, nature/culture relations. Indeed, it seems "merely" represent realistic day-to-day lives of ordinary people living in contemporary Japan and Canada, and in very minute and particular details at that. Indeed, the central action of the main characters of the novel seems very traditional, that is on the one hand writing a diary by a teenage girl who is counting the days and weeks before her suicide and on the other hand reading it by a female novelist who happens to find her diary several years later. Nevertheless, I would like to suggest that underneath this traditional narrative surface are simmering post-humanist and post-anthropocentric worldviews beyond liberal Humanism which takes human beings to be exceptional against human or non-human others. Not only in narrative contents and characterizations but also through narrative structure and strategies, the novel enacts post-humanist and post-anthropocentric worldviews which are interestingly drawn from both age-old Buddhist ideas and modern eco-philosophy and quantum physics. I would like to stress that what triggers the author's fictional experiments helping our rethinking and redefining "what human beings are" and "what the relation between humans and nonhumans" is not merely intellectual interests but her keen and passionate response to the heart-breaking pains and sufferings of human and nonhuman beings caused by the contemporary natural-artificial catastrophes and techno-scientific predicaments.

• Korean Journal of Materials Research
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• v.33 no.5
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• pp.175-188
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• 2023

Water electrolysis holds great potential as a method for producing renewable hydrogen fuel at large-scale, and to replace the fossil fuels responsible for greenhouse gases emissions and global climate change. To reduce the cost of hydrogen and make it competitive against fossil fuels, the efficiency of green hydrogen production should be maximized. This requires superior electrocatalysts to reduce the reaction energy barriers. The development of catalytic materials has mostly relied on empirical, trial-and-error methods because of the complicated, multidimensional, and dynamic nature of catalysis, requiring significant time and effort to find optimized multicomponent catalysts under a variety of reaction conditions. The ultimate goal for all researchers in the materials science and engineering field is the rational and efficient design of materials with desired performance. Discovering and understanding new catalysts with desired properties is at the heart of materials science research. This process can benefit from machine learning (ML), given the complex nature of catalytic reactions and vast range of candidate materials. This review summarizes recent achievements in catalysts discovery for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The basic concepts of ML algorithms and practical guides for materials scientists are also demonstrated. The challenges and strategies of applying ML are discussed, which should be collaboratively addressed by materials scientists and ML communities. The ultimate integration of ML in catalyst development is expected to accelerate the design, discovery, optimization, and interpretation of superior electrocatalysts, to realize a carbon-free ecosystem based on green hydrogen.

• Journal of Cardiovascular Imaging
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• v.30 no.1
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• pp.62-75
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• 2022

BACKGROUND: Due to its location very close to the bundle of His, mitral annulus calcification (MAC) might be associated with the development of atrioventricular (AV) conduction disturbances. This study assessed the association between MAC and AV conduction disturbances identified by cardiac implantable electronic device (CIED) use and electrocardiographic parameters. The association between MAC and traditional cardiovascular risk factors was also assessed. METHODS: This cross-sectional study analyzed 14,771 participants, predominantly men aged 60-75 years, from the population-based Danish Cardiovascular Screening trial. Traditional cardiovascular risk factors were obtained. Using cardiac non-contrast computed tomography imaging, MAC scores were measured using the Agatston method and divided into absent versus present and score categories. CIED implantation data were obtained from the Danish Pacemaker and Implantable Cardioverter Defibrillator Register. A 12-lead electrocardiogram was available for 2,107 participants. Associations between MAC scores and AV conduction disturbances were assessed using multivariate regression analyses. RESULTS: MAC was present in 22.4% of the study subjects. Participants with pacemakers for an AV conduction disturbance had significantly higher MAC scores (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.01-1.23) than participants without a CIED, whereas participants with a CIED for other reasons did not. Prolonged QRS-interval was significantly associated with the presence of MAC (OR, 1.45; 95% CI, 1.04-2.04), whereas prolonged PQ-interval was not. Female sex and most traditional cardiovascular risk factors were significantly associated with high MAC scores. CONCLUSIONS: MAC was associated with AV conduction disturbances, which could improve our understanding of the development of AV conduction disturbances.