• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권5호
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• pp.404-416
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• 2006

Purpose : This study was to clarify the changes in mandibular condyle after unilateral mandibular distraction osteogenesis throughout histological changes and expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2). Materials & Methods : Intraoral distractors were placed via submandibular incision in 8 dogs. Two unoperated animals served as controls. Distraction was performed five days after osteotomy as a rate of 0.5 mm twice per day for 10 days. Two animals were sacrificed on 7, 14, 28, and 56 days after completion of distraction, respectively. Ipsilateral condyles were harvested and processed for histological and immunohistochemical examinations. Results : The condyle cartilage is separated into four layers: fibrous layer, proliferative layer, hypertrophic layer, and calcified layer. At 7 days and 14 days after distraction, the condylar cartilage showed the decreased thickness of the articular cartilage and reduced cellularity. At 28 days after distraction, there was an increase in cellularity of fibrous, proliferative, and hypertrophic layer. However, it demonstrated reduced cellularity compared to the control. At 56 days of after distraction, the articular cartilage was an almost normal histologic structure. Positive Safranin-O staining, indicative of sulfated proteoglycans, was examined in the condylar cartilge of nonloaded control. At 7 days and 14 days after distraction, the sulfated proteoglycans is almost completely depleted from the noncalcified part of the condylar cartilage. At 28 days after distraction, there was an increase in Safranin-O staining intensity. However, the staining intensity of the experimental condyle was weaker than that of the control. At 56 days of after distraction, the condylar cartilage showed almost normal Safranin-O staining pattern. In control condyle, MMP-2 immunostaining was seen in fibrous, proliferative, and hypertrophic layer of condylar cartilage, however, it demonstrated lack of staining in fibrous and proliferative layer. At 7 days and 14 days after distraction, strong MMP-2 immunoreactivity was seen in the fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 28 days after distraction, MMP-2 immunostaining was seen in the fibrous and hypertrophic layer of condylar cartilage, however, their immunoactivity was reduced. At 56 days after distraction, MMP-2 immunoreactivity showed almost normal immunostaining pattern. In control condyle, TIMP-2 immunostaining was primarily seen in fibrous and hypertrophic layer of condylar cartilage, however, it demonstrated lack of staining in proliferative layer. At 7 days after distraction, very weak TIMP-2 immunoreactivity appeared in fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 14 days after distraction, weak TIMP-2 immunoreactivity was seen in the fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 28 days after distraction, TIMP-2 immunoreactivity was increased in the fibrous and hypertrophic layer of condylar cartilage. At 56 days after completion of distraction, TIMP-2 immunoreactivity showed almost normal immunostaining pattern. Conclusions : The results show that short-term outcome of physiologic distraction osteogenesis may lead to degenerative changes in the condylar cartilage. These alterations in the condylar cartilage may be considered as a pressure-related degeneration of the cartilage tissue. However, the long-term results suggest that the condylar cartilage display repair activity after mandibular distraction osteogenesis.

• Geomechanics and Engineering
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• 제5권2호
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• pp.87-97
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• 2013

In this paper, a novel fibrous material known as axially reinforced braided composite rods (BCRs) have been developed for reinforcement of soils. These innovative materials consist of an axial reinforcement system, comprised of longitudinally oriented core fibres, which is responsible for mechanical performance and, a braided cover, which gives a ribbed surface texture for better interfacial interactions with soils. BCRs were produced using both thermosetting (unsaturated polyester) and thermoplastic (polypropylene) matrices and synthetic (carbon, glass, HT polyethylene), as well as natural (sisal) core fibres. BCRs were characterized for tensile properties and the influence of core fibres was studied. Moreover, BCRs containing carbon fibre in the core composition were characterized for piezoresistivity and strain sensing properties under flexural deformation. According to the experimental results, the developed braided composites showed tailorable and wide range of mechanical properties, depending on the core fibres and exhibited very good strain sensing behavior.

• Journal of Chest Surgery
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• 제20권3호
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• pp.593-597
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• 1987

Mesothelioma is a primary tumor of the pleura. There are two forms of mesotheliomas; diffuse form and localized form. The majority of localized mesotheliomas are benign, but the tumor with pedicle recur at 20% after removal of it. Malignant localized fibrous mesothelioma is differential diagnosed pathologically and clinically with diffuse mesothelioma. Symptoms of localized mesothelioma are generally related to the size of the tumor. We presented one case of malignant localized fibrous mesothelioma. The patient was 32 years old female and chief complaints were dyspnea and dry cough. Sputum cytology and needle lung biopsy were not able to diagnose definitely the tumor. Explothoracotomy was carried out for definite tissue biopsy. At the time of operation, huge adult head size mass was in the right thoracic cavity. The surface of the mass was nodular, multilobular and had hard consistency. Pedicle was formed above first rib and its diameter was 4.5cm. There was no adhesion except to RUL. Frozen biopsy suggested mesothelioma. Extirpation of the mass, right upper lobectomy. and partial pleurectomy were carried out.

• Journal of Chest Surgery
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• 제29권1호
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• pp.112-114
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• 1996

Localized fibrous tumor of the pleura (LFTP) is of submesothelial fibrous origin, which has been called pleural fibroma and has been confused with mesothelioma. We experienced a case of LFTP in a twenty nine year old man. The tumor arose from the right parietal pleura with long stalk. Chest X-ray and CT scan showed a 6$\times$5$\times$4cm well-defined mass in the right costophrenic angle. Wo evidence of metastasis was noted. Exploratory thoracotomy with enbloc excision of 6$\times$5$\times$4cm mass was done. The fine needle aspiration cytology and histopathologic features indicated the tumor to be malignant, and biologic behavior was discussed.

• 한국분말재료학회지
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• 제9권3호
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• pp.148-152
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• 2002

The microstructures and indentation fracture of pressureless-sintered $DyNbO_4$ crystalline were investigated as a basic study for the application of weak phase of fibrous monolithic composites. They were comprised with many lamella twins as well as micro-cracks at the grain boundaries. The hardness at room temperature was remarkably low value(575 Hv) due to the low relative density and existence of microcracks at grain boundaries. The main fracture mode was a typical intergranular fracture, and showed remarkable micro-cracking effect. The heavy plastic deformation was observed around the site of indentation. In addition, the $DyNbO_4$ was expected to apply as a weak phase in the fibrous monolithic composites because of the low hardness and easily plastic deformation that could be led the preferable pulled-out and microcracking toughening under the failure.

• Journal of Korean Neurosurgical Society
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• 제30권12호
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• pp.1439-1442
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• 2001

Solitary fibrous tumor(SFT) is a spindle cell neoplasm that usually arises in the pleura. Its involvement of the meninges is rare but increasingly being reported. Our case was a 33-year-old man who presented with clonic seizure around the right mouth angle and sensory disturbance at the right hand. Radiological studies showed a large extra-axial, dural-based mass in the left fronto-parietal region, typically isointense with gray matter and heterogeneous strong enhancement on T1-weighted images. Histologically, the tumor was composed of spindle-shaped cells growing in fascicles within the collagenous matrix. Immunohistochemical staining demonstrated diffuse CD34 positivity. Awareness of this neoplasm is necessary to accurate diagnosis.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.65-69
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• 2002

An Al film deposited on the Kovar alloy substrate was anodically-bonded to the borosilicate glass, and the bond interfaces was closely investigated by transmission electron microscopy. Al oxide was found to form a layer ~l0 nm thick at the bond interface, and fibrous structure of the same oxide was found to grow epitaxially in the glass from the oxide layer. The fibrous structure grew with the bonding time. The mechanism of the formation of this fibrous structure is proposed on the basis of the migration of Al ions under the electric field. Penetration of Al into glass beyond the interfacial Al oxide was not detected. The comparison of the amount of excess oxygen ions generated in the alkali depletion layer with that incorporated in the Al oxide suggests that the growth of the alkali-ion depletion layer is controlled by the consumption of excess oxygen to form the interfacial Al oxide.

• Journal of Chest Surgery
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• 제20권2호
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• pp.358-366
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• 1987

A case of malignant fibrous histiocytoma [MFH] of left pulmonary artery was reported in the 27 year-old male. He was admitted because of hemoptysis for several times. Chest x-ray revealed nodular lesions in left hilar area and left upper lobe. A left thoracotomy was performed followed left upper lobectomy. The main tumor was originated from the pulmonary arterial bifurcation and proximal portion of the left pulmonary artery. By light microscopy, there were many pleomorphic giant cells, which displayed the storiform pattern. And in those area, dilated or compressed vascular channels were involved by tumor cells, suggesting origin of This tumor. Pulmonary artery angiography and chest CT revealed this tumor was originated from pulmonary artery. It would be the first reported primary malignant fibrous histiocytoma of the pulmonary artery in our country. Postoperative prognosis was uneventful, but recently he was suffered from dyspnea, that was noticed by OVD follow-up for 1 month, probably the heart failure sign due to pulmonary arterial flow obstruction.

• Korea-Australia Rheology Journal
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• 제21권1호
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• pp.71-79
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• 2009

The incomplete saturation and the void formation during the resin infiltration into fibrous porous media in the resin transfer molding process cause failure in the final product during its service. In order to better understand flow behavior during the filling process, a finite-element scheme for transient flow simulation across the micro-structured fibrous media is developed in the present work. A volume-of- fluid (VOF) method has been incorporated in the Eulerian frame to capture the evolution of flow front and the vertical periodic boundary condition has been combined to avoid unwanted wall effect. In the microscale simulation, we investigated the transient filling process in various fiber structures and discussed the mechanism leading to the flow fingering in the case of random fiber distribution. Effects of the filling pressure, the shear-thinning behavior of fluid and the volume fraction on the flow front have been investigated for both intra-tow and the inter-tow flows in dual-scale fiber tow models.

• 한국입자에어로졸학회지
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• 제5권1호
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• pp.9-16
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• 2009

Pressure drop and particle removal efficiency of two commercial fibrous medium filters were measured with 20~1,000 nm sized aerosolized KCl particles. Pressure drop and particle removal efficiency were also theoretically predicted and the results qualitatively agreed with the experimental data. For this given particle removal efficiency, a filter design method for obtaining minimum pressure drop (and therefore minimum fan power) was suggested in this study by selecting solidity and fiber diameter as parameters. Therefore, by carrying out theoretical and experimental approaches together, this paper introduced a way of finding conditions for low pressure drop and high performance of a fibrous filter, especially if the filter would be used in mechanical ventilation system.