• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.5
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• pp.303-309
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• 2017

In this study, the characteristics of the temperature generated by light irradiation, on the surface of a biological tissue with an abnormal tissue part (paraffin) and at the surroundings of the abnormal tissue were studied by numerical and experimental methods. The temperature in the tissue was solved using the computational heat transfer and was compared with the temperature measured with thermocouples. The effects of the light wavelength and the irradiation time on the temperature distribution were analyzed. As a result, the temperature distribution from the irradiation of light in the biological tissue was different when there was an abnormal tissue part. The temperature in the biological tissue with the abnormal tissue part was higher than in a normal tissue.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.4
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• pp.330-335
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• 2002

The study was performed to investigate the comparison of relative signal intensity of normal- and abnormal-side retrodiscal tissue, and relationship between clinical examination, joint effusion and relative signal intensity of retrodiscal tissue in patients with unilateral TMJ internal derangement. The study group comprised 19 females and 9 males, with a mean age of 29 years. After measurements of the signal intensity were made on the MR imager for the T2 weighted images on retrodiscal tissue and brain gray matter, we calculated relative value and tried to find relationship between clinical examination, joint effusion and relative signal intensity on normal- and abnormal-side. The results are as follows. 1. The gray matter is an appropriate reference point. 2. The relative signal intensity is high significantly in abnormal-side retrodiscal tissue compared with normal-side retrodiscal tissue. 3. The relative signal intensity is high significantly in painful joints compared with nonpainful joints and in joints with joint effusion compared with joints without joint effusion. 4. The relative signal intensity in normal joints, joints with reduction and joints without reduction is increased in order significantly.

• Journal of Biomedical Engineering Research
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• v.6 no.2
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• pp.43-52
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• 1985

In this paper, the depth and attenuation coefficient are estimated from the mutilayered liver tissue which contained a inhomogeneous one using reflected ultrasonic signals and the abnormal one is detected quantitatively. Regarding a liver tissue as several reflectors, we analyzed each one by the frequency spectral difference method and discussed its attenuation characteristics. For the verification of this method, the liver pantom and acryle are used. And also we proved the usefulness through the experiment.

• Journal of Korean Dental Science
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• v.16 no.1
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• pp.99-103
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• 2023

McCune-Albright syndrome (MAS) is a disease with clinical features such as fibrous dysplasia in which normal bone tissue is replaced with abnormal fibrous tissue, abnormalities in the endocrine system, and cafe-au-lait spots on the skin. Although MAS patients are generally known to have reduced bone healing ability, postoperative healing after invasive surgical extraction is still not clearly known due to its relatively rare occurrence. In this report, a 25-year-old female patient, who had been diagnosed with MAS and had a history of abnormal bone healing after fractures of her extremities, underwent surgical extraction of the mandibular third molar with surrounding bone removal. Postoperatively, the patient showed favorable soft tissue and bone healing at the surgical site without abnormal findings such as newly developed fibro-osseous lesions, postoperative infection, or osteomyelitis.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1665-1668
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• 2008

Arrhythmia causes sudden cardiac death. In the past, there were medical limitations in finding the cause of arrhythmia. As an alternative solution for research of arrhythmia, there have been studies to find the causes of arrhythmia by producing a virtual heart model. Medically, arrhythmia has two main causes: abnormal occurrence of action potential and abnormal conduction of action potential. Based on these, the tachycardia, which is one of the arrhythmia, was manifested and the phenomenon of ventricular fibrillation was numerically analyzed in this study. For this purpose, an electrophysiological model of ventricular cells was implemented, which was subsequently applied to the reaction-diffusion partial differential equation to interpret the macroscopic conduction phenomenon in two-dimensional tissues. The ventricular fibrillation refers to a condition where several irregular waves occur in cardiac tissue, whose generation mechanism is pathologically related to the cardiac tissue.

• Journal of Chest Surgery
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• v.15 no.1
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• pp.27-34
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• 1982

Pulmonary sequestration Is an unusual congenital malformation characterized by the presence of nonfunctioning lung tissue which usually has no communication with the normal bronchial tree and which receives its blood supply from an anomalous systemic artery instead of a pulmonary arterial branch. Two forms of pulmonary sequestration occur: Intralobar sequestration, in which the abnormal pulmonary tissue is incorporated within the normal lung and shares a common covering of visceral pleura, and extralobar sequestration, in which the abnormal pulmonary tissue is separated from the normal lung and has its own pleural investment. Since 1970, five cases of pulmonary sequestration were operated at the Department of Thoracic and Cardiovascular Surgery, College of Medicine, Seoul National University. 1. Among five cues, one was male and the others were female. 2. All were intralobar type and involved left lower lobe. 3. There was no operative mortality following left lower lobectomy and ligation of the aberrant artery.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.9-10
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• 2002

Human circulatory system between heart and tissue is not directly connected in normal condition but mandatory to go through the capillary system in order to fulfill its physiologic aim to deliver oxygen and nutrients, etc. to the tissue and retrieve used blood together with waste products from the tissue properly. When abnormal connection between arterial and venous system (AV fistula), these two circulatory systems respond differently to the hemodynamic impact of this abnormal connection between high pressure (artery) and low pressure (vein) system. Depending upon the location and/or degree (e.g. size and flow) of fistulous condition, each circulatory system exerts different compensatory hemodynamic response to this newly developed abnormal inter-relationship between two systems in order to minimize its hemodynamic impact to own system of different hemodynamic characteristics. Pump action of the heart can assist the failing arterial system directly to maintain arterial circulation against newly established low peripheral resistance by the AV fistula during the compensation period, while it affects venous system in negative way with increased venous loading. However, the negative impact of increased heart action to the venous system is partly compensated by the lymphatic system which is the third circulatory system to assist venous system independently with different hemodynamics. The lymphatic system with own unique Iymphodynamics based on peristaltic circulation from low resistance to high resistance condition, also increases its circulation to assist the compensation of overloaded venous system. Once these compensation mechanisms should fail to fight to newly established hemodynamic condition due to this abnormal AV connection, each system start to show different physiologic ${\underline{de}compensation}$ including heart and lymphatic system. The vicious cycle of decompensation between arterial and vein, two circulatory system affecting each other by mutually negative way steadily progresses to show series of hemodynamic change throughout entire circulation system altogether including heart. Clinical outcome of AV fistula from the compensated status to decompensated status is closely affected by various biological and mechanical factors to make the hemodynmic status more complicated. Proper understanding of these crucial biomechanical factors iii particular on hemodyanmic point of view is mandatory for the advanced assessment of biomechanical impact of AV fistula, since this new advanced concept of AY fistula based on blomechanical information will be able to improve clinical control of the complicated AV fistula, either congenital or acquired.

• Biomedical Science Letters
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• v.11 no.1
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• pp.23-29
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• 2005

Molecular imaging with targeted contrast agents enables tissues to be distinguished by detecting specific cell-surface receptors. In the present study, a ligand-targeted acoustic nanoparticle system is used to identify angioplasty-induced expression of tissue factor by smooth muscle cell within carotid arteries. Pig carotid arteries were overstretched with balloon catheters, treated with tissue factor-targeted or a control nanoparticle system, and imaged with intravascular ultrasound before and after treatment. Tissue factor-targeted emulsion bound and increased the echogenicity and gray-scale levels of overstretched smooth muscle cell within the tunica media, versus no change in contralateral control arteries. Expression of stretch-induced tissue factor in carotid artery media was confirmed by immunohistochemistry. The potential for abnormal thrombogenicity of balloon-injured arteries, as reflected by smooth muscle expression of tissue factor, was imaged using a novel, targeted, nanoparticulate ultrasonic contrast agent.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.222-226
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• 2007

We suggest the fluorescence endoscope system that has light source apparatus providing selectable white or excitation light. White light source generates normal color images and is easily switched over to excitation light with the wide spectrum range from 380 nm to 580 nm. 5-ALA is deposited selectively in the abnormal tissue like cancer and causes fluorescence in the red spectrum range when excited by blue spectrum range. In addition, the others of excitation light make the color background image by reflected light to allow accurate orientation and visualization of the abnormal tissue and around. According to clinical studies, the fluorescence intensity contrast that defines the fluorescence intensity of lesion over the fluorescence intensity of around has more than 2 in tumour. Proposed system is useful and objective way in early diagnosis. Furthermore, it can be used in the biopsy for tumour classification at the highest fluorescence intensity point.

• Journal of Yeungnam Medical Science
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• v.36 no.2
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• pp.85-91
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• 2019

The incidence of gastric mucosa-associated lymphoid tissue (MALT) lymphoma is increasing worldwide, but the diagnosis is difficult. Most patients are asymptomatic or complain of nonspecific gastrointestinal symptoms. As the endoscopic features of gastric MALT lymphoma are variable and nonspecific, the possibility of this condition may be overlooked during esophagogastroduodenoscopy, and it remain undiagnosed. Therefore, this condition needs to be considered when an abnormal mucosa is observed during this procedure. Biopsy performed during endoscopy is the primary diagnostic test, but false negative results are possible; large numbers of samples should be collected from both normal and abnormal mucosae. Endoscopic ultrasonography is useful to assess the depth of invasion and to predict the treatment response. After treatment, follow-up tests are required every 3 months until complete remission is achieved, and annually thereafter. Early diagnosis of gastric MALT lymphoma is difficult, and its diagnosis and follow-up require wide experience and competent endoscopic technique.