• Macromolecular Research
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• v.11 no.6
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• pp.495-500
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• 2003

UV-induced graft polymerization of glycidyl methacrylate (GMA) to a polypropylene (PP) membrane was carried out in the vapor phase with benzophenone (BP) as a photoinitiator. Attenuated total reflection Fourier transform infrared spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM) were utilized to characterize the copolymer. The degree of grafting increased with increasing reaction time, increased UV irradiation source intensity, and increased immersion concentration of the BP solution. The optimum synthetic condition for the PP-g-GMA membrane was obtained with a reaction time of 2 hrs, a UV irradiation source intensity of 450 W, and an immersion concentration of the BP solution of 0.5 mol/L. The pure water flux decreased upon increasing the degree of grafting and increasing the amount of diethylamino functional group introduced. The analysis of AFM and SEM images shows that the graft chains and diethylamino groups of PP-g-GMA grew on the PP membrane surface, resulting in a change in surface morphology.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.1
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• pp.34-42
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• 2019

Objectives: Various bone graft substitute materials are used to enhance bone regeneration in the maxillofacial skeleton. In the recent past, synthetic graft materials have been produced using various synthetic and natural calcium precursors. Very recently, eggshell-derived hydroxyapatite (EHA) has been evaluated as a synthetic bone graft substitute. To assess bone regeneration using EHA in cystic and/or apicectomy defects of the jaws through clinical and radiographic evaluations. Materials and Methods: A total of 20 patients were enrolled in the study protocol (CTRI/2014/12/005340) and were followed up at 4, 8, 12, and 24 weeks to assess the amount of osseous fill through digital radiographs/cone-beam computed tomography along with clinical parameters and complications. Wilcoxon matched pairs test, means, percentages and standard deviations were used for the statistical analysis. Results: The sizes of the lesions in the study ranged from 1 to 4 cm and involved one to four teeth. The study showed significant changes in the formation of bone, the merging of material and the surgical site margins from the first week to the first month in all patients (age range, 15-50 years) irrespective of the size of the lesions and the number of teeth involved. Bone formation was statistically significant from the fourth to the eighth week, and the trabecular pattern was observed by the end of 12 weeks with uneventful wound healing. Conclusion: EHA showed enhancement of bone regeneration, and healing was complete by the end of 12 weeks with a trabecular pattern in all patients irrespective of the size of the lesion involved. The study showed enhancement of bone regeneration in the early bone formative stage within 12 weeks after grafting. EHA is cost effective and production is environment friendly with no disease transfer risks. Thus, natural bioceramics will play an important role in the reduction of costs involved in grafting and reconstruction.

• Journal of Chest Surgery
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• v.57 no.4
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• pp.413-417
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• 2024

A 70-year-old man with dilated cardiomyopathy underwent left ventricular assist device (LVAD) implantation, using a HeartWare ventricular assist device, as a bridge to candidacy. After 26 months, computed tomography (CT) angiography indicated stenosis in the LVAD outflow graft; however, the patient was asymptomatic, prompting a decision to manage his condition with close monitoring. Ten months later, the patient presented with dizziness and low-flow alerts. Subsequent CT angiography revealed a critical obstruction involving the entire LVAD outflow graft. The patient underwent emergency surgery, during which an organized seroma causing the graft obstruction was found between a wrapped expanded polytetrafluoroethylene (ePTFE) graft and a Dacron outflow graft. The covering of the outflow graft was removed, along with the organized seroma. Following removal of the ePTFE wrap and decompression of the outflow graft, normal LVAD flow was reestablished. The practice of wrapping the outflow graft with synthetic material, commonly done to facilitate later redo sternotomy, may pose a risk for outflow graft obstruction.

• Journal of Chest Surgery
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• v.19 no.2
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• pp.288-294
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• 1986

During the period from Mar. 1983 to Feb. 1986, 22 patients with vascular trauma were treated at Capital Armed General Hospital. 1] 11 patients had arterial injury alone, 6 patients had venous injury alone, and 5 patients had both arterial and venous injuries. 2] The mechanism of injury in these 22 patients was 7 penetrating non-gun shot wounds, 5 blast fragments injuries, 4 iatrogenic injuries, 4 blunt injuries, 2 gun shot wounds. 3] The method of 16 arterial repair was 5 autogenous saphenous vein graft, 8 synthetic vascular graft, 1 end to end anastomosis, 2 lateral suture. Midterm patency of 16 repairs was 100% within 1 months. 4] The method of 11 venous repair was 1 autogenous saphenous vein graft, 2 onlay vein patch, 2 ligation, 1 lateral suture. The thrombotic obstructions occurred in 4 repairs [36.4%], but they were resolved somewhat with heparinization. 5] Uncommon cases of false aneurysm of internal carotid artery and laceration of retrohepatic inferior vena cava were summarized.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.317-317
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• 2006

Dendronized linear polymers have recently come forward as new materials for nanoscale applications. These "molecular cylinders" may be modified with specific chemical makeup, rigidity, surface decoration, and backbone properties much like their spherical analogs, dendrimers. There exist three main synthetic pathways to yield dendronized polymers: (i) graft-to; (ii) graft-from; and (iii) macromonomer. We present an efficient "graft-to" approach towards dendronized microstructures utilizing click chemistry. With the capacity to manipulate their chemical composition, these dendronized structures have already found broad use in site-isolation for catalysis, nanolithography and organic light emitting diodes. These and other potential applications of these materials will be also presented.

• Journal of Chest Surgery
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• v.31 no.7
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• pp.722-724
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• 1998

Acute mediastinitis and subsequent graft infection following aorta surgery poses a difficult problem, as infected synthetic material must be completely removed for resolution of infection. Here we report a case of successful management of acute mediastinitis following hemiarch replacement for acute aortic dissection with omental flap transfer leaving infected graft in situ.

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.53-62
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• 2011

Purpose: Even though Augmentation rhinoplasty is very popular surgical procedure, it is not easy to obtain ideal materials for augmentation. Many different synthetic materials are used but frequent complications are seen such as infection, extrusion, deform, and dislocation. Autologous tissues were used for augmentation rhinoplasty. We used dermofat graft and fat injection in augmentation rhinoplasty minimizing these problems. Methods: From 2006 to 2009, we used autologous tissues in augmentation rhinoplasty in 40 patients, 20 patients with dermofat graft and other 20 patients were treated with fat injection only. Dermofats were harvested from sacral area. gluteal fold, groin and preexisting scar tissue. Dermofats were inserted with small stab wound and fat tissues were injected as Coleman's technique. The patients were followed up 6 months to 5 years. Results: Most of the patients were satisfied in shape and height the nose. Early complications such as hematoma, infection and seroma were not found. Secondary fat injection was performed in 3 patients (15%) of dermofat graft group instead of 7 patients (35%) of fat injection only group. Conclusion: We obtained satisfactory results in augmentation rhinoplasty with dermofat graft and fat injection. Secondary fat injections were more often in fat injection group than dermofat graft group. Dermofat graft and fat injection could be another alternative technique for augmentation rhinoplasty and fat injection could be a secondary adjunctive treatment for undercorrection due to absorption.

• 대한치주과학회:학술대회논문집
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• 2007.11a
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• pp.128-129
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• 2007

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.281-285
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• 2010

Hemodialysis vascular access dysfunction (HVAD) due to the aggressive development of venous neointimal hyperplasia remains a major complication for patients with synthetic arteriovenous grafts. Paclitaxel-coated expanded polytetrafluoroethylene (ePTFE) grafts effectively prevent neointimal hyperplasia and stenosis. However, perigraft inflammation or edema can be another complication of ePTFE grafts, preventing early cannulation. Three different types of ePTFE grafts, including grafts without paclitaxel coating (control group, n = 12), grafts with paclitaxel coating at a dose density of $0.61ug/mm^2$ (low concentration group, n = 12), and grafts with paclitaxel coating at a dose density of $1.15ug/mm^2$ (high concentration group, n = 12) were placed in the backs of 12 rabbits, simultaneously. Six rabbits were euthanized after one week and the remaining six were euthanized two weeks after implantation. Perigraft inflammation, graft wall inflammation, stromal cell proliferation, blood vessel formation, tissue necrosis and edema were analyzed for the grafts in each animal. Inflammation surrounding the paclitaxel-coated grafts was significantly reduced compared to the control group. Stromal cell layers were detected at the interface between the graft and the surrounding tissue in the control group, infiltrated into the graft interstices, and differentiated into myofibroblasts for graft healing. Paclitaxel-coated grafts inhibited stromal cell proliferation and infiltration into the graft wall. Tissue necrosis and edema were not detected in either of the paclitaxel-coated graft groups.

• The Journal of the Korean dental association
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• v.46 no.4
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• pp.222-231
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• 2008

Various maxillary sinus floor augmentation techniques were common performed and in the most cases, many kinds of bone graft materials were used. The graft materials are autogenous bone or other biomaterials of human, animal or synthetic origin. But these cases report describes a new surgical technique by which dental implants are inserted in a void space created by elevating the sinus membrane without additional graft material in atrophic posterior maxilla. We created lateral bony window using piezoelectric device and elevated the schneiderian membrane in five patients and was repositioned with bony window in five patients, without any bone graft. From the clinical and histological results, it is found there is potential capacity for bone formation and placement of implants in the maxillary sinus without the use of bone grafts or bone substitutes.