• 제목/요약/키워드: graft modification

검색결과 62건 처리시간 0.027초

광범위 종양절제술 후 발생한 하악 결손의 재건 : 결손부위에 따른 비골 유리 피판의 다양한 디자인 (Reconstruction of Mandible Defect after Tumor Ablation Surgery : Versatility of Fibular Free Flap Design)

  • 설철환;이영대;탁관철;유대현
    • 대한두경부종양학회지
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    • 제21권2호
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    • pp.190-195
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    • 2005
  • Background and Objectives: Fibula is the flap of choice for reconstruction of wide mandible defects after tumor ablation surgery. In mandible reconstruction, restoring the mandible frame to provide mandibular contour and dental arch while restoring masticatory function are important. Even though vascularized fibula can be osteotomized freely, proper design and flap insetting is not easy because of its three dimensional structure and difference in design according to the defect sites. We reviewed patients who underwent mandible reconstruction with fibular flaps according to the defect sites and suggest proper modification methods of fibular flap according to the various defects sites after tumor ablation surgery. Materials and Methods: Twelve consecutive mandible reconstruction with fibular free flaps were performed for defects after tumor ablation surgery. Patients were classified into 4 groups according to the type of mandibular defect(Group 1 : defect on central segment including symphysis, Group 2 : defect on lateral segment(with or without central segment) confined to body, Group 3 : defect on body and ascending ramus that does not include the condyle, Group 4 : defect including the condyle). Results: We suggest different modification methods of fibular free flap for each patient group. Group 1, 3 ; contour by using multiple closing wedge osteotomy. Group 2 ; single or double barrel reconstruction without wedge osteotomy. Group 4 ; contour using single or multiple wedge osteotomy and condylar reconstruction with costochondral graft. Conclusion: Fibular free flaps can be contoured to any desired shape after multiple osteotomies to restore various mandibular defects. It is a reliable and versatile method for reconstruction of mandibular defects after tumor ablation surgery.

Surface Modification of Polypropylene Membrane by ${\gamma}$ Irradiation Methods and their Solutes Permeation Behaviors

  • Shim, J. K.;Lee, S. H.;Kwon, O. H.;Lee, Y. M.;Nho, Y. C.
    • 한국막학회:학술대회논문집
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    • 한국막학회 1998년도 춘계 총회 및 학술발표회
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    • pp.99-101
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    • 1998
  • 1. Introduction : The conventional grafting polymerization technique requires chemically reactive groups on the surface as well as on the polymer chains. For this reason, a series of prefunctionalization steps are necessary for covalent grafting. The surface prefunctionalizational technique for grafting can be used to ionization radiation, UV, plasma, ion beam or chemical initiators. Of these techniques, radiation method is one of the useful methods because of uniform and rapid creation of active radical sites without catalytic contamination in grafted samples. If the diffusion of monomer into polymer is large enough to come to the inside of polymer substrate, a homogeneous and uniform grafting reaction can be carried out throughout the whole polymer substrate. Radiation-induced grafting method may attach specific functional moieties to a polymeric substrate, such as preirradiation and simultaneous irradiation. The former is irradiated at backbone polymer in vacuum or nitrogen gas and air, and then subsequent monomer grafting by trapped or peroxy radicals, while the latter is irradiated at backbone polymer in the presence of the monomer. Therefore, radiation-induced polymerization can be used to modification of the chemical and physical properties of the polymeric materials and has attracted considerable interest because it imparts desirable properties such as blood compatibility. membrane quality, ion excahnge, dyeability, protein adsorption, and immobilization of bioactive materials. Synthesizing biocompatible materials by radiation method such as preirradiation or simultaneous irradiation has often used $\gamma$-rays to graft hydrophilic monomers onto hydrophobic polymer substrates. In this work, in attempt to produce surfaces that show low levels of anti-fouling of bovine serum albumin(BSA) solutions, hydroxyethyl methacrylate(HEMA) was grafted polypropylene membrane surfaces by preirradiation technique. The anti-fouling effect of the polypropylene membrane after grafting was examined by permeation BSA solution.

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저밀도 폴리에틸렌의 표면개질과 이를 이용한 저밀도 폴리에틸렌/알루미늄 라미네이트의 접착특성 (Surface Modification of Low Density Polyethylene and Adhesion Characteristics of Low Density Polyethylene/Aluminum Laminate)

  • 정배영;류승훈
    • Elastomers and Composites
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    • 제36권3호
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    • pp.195-200
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    • 2001
  • UV조사 하에서 아크릴산의 그라프팅을 이용한 LDPE의 표면개질을 XPS와 접촉각을 이용하여 살펴보았으며, 이에 따른 알루미늄/LDPE 라미네이트의 접착력 변화를 살펴보았다. 접촉각은 UV조사시간이 증가함에 따라 초기에 급격히 감소하다가 점차 일정한 값을 나타내었다. 이는 초기에는 LDPE 표면에 그라프트된 아크릴산에 의해 친수성이 급격히 증가하다가 표면의 아크릴산 농도가 증가함에 따라 친수성의 변화가 상대적으로 감소하기 때문으로 생각된다. 이러한 결과는 XPS를 이용한 O1s/C1s 비의 증가로도 확인할 수 있었다. 아크릴산이 그라프트된 LDPE와 알루미늄의 접착력은 순수한 LDPE를 이용하였을 때에 비하여 약 30배치 증가를 나타내었으며 이는 아크릴간의 그라프트에 의해 LDPF의 표면 극성기가 증가하였기 때문이다. 황산/isodium dichromate를 이용하여 알루미늄 표면을 처리한 경우 보다 뛰어난 접착력을 나타내었다. 아세트산의 존재하에서 LDPE/알루미늄 라미네이트의 계면접착력은 급격히 감소함을 알 수 있었다.

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함산소불소화가 저밀도 폴리에틸렌 표면의 그라프트 중합 및 그 표면 특성에 미치는 영향 (Effects of Oxyfluorination on Surface Graft Polymerization of Low Density Polyethylene Film and Its Surface Characteristics)

  • 윤석민;우상욱;정의경;배병철;박인준;이영석
    • 공업화학
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    • 제21권3호
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    • pp.343-348
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    • 2010
  • 저밀도 폴리에틸렌(low density polyethylene, LDPE) 필름의 표면을 다양한 반응 조건하에서 함산소불소화하여 hydroperoxide 관능기를 도입시켜 표면특성을 변화시켰다. 또한 생성된 hydroperoxide 관능기를 반응 개시제로 친수성 그룹을 가지는 단량체인 acryl amide (AM)와 소수성 그룹을 가지는 단량체인 methyl methacrylate (MMA)를 그라프트 중합시켜 LDPE 필름의 표면을 2차 개질하였다. 또한 LDPE, 함산소불소화 된 LDPE (OFPE), AM 및 MMA 단량체가 그라프트 된 OFPE 필름의 표면특성은 1,1-diphenyl-2-picrylhydrazyl (DPPH), 감쇠전반사 분광법, 시차주사 열량분석기 및 접촉각 측정법 등으로 분석하였다. DPPH 라디칼 분석법의 결과로부터, OFPE의 hydroperoxide 관능기의 양은 함산소불소화 총압력과 F2 가스의 부분압이 증가함에 따라 증가함을 알 수 있었다. 접촉각 및 표면 자유에너지 분석결과로부터, 함산소불소화에 의해서 생성된 hydroperoxide 관능기와 AM과 같은 친수성 그룹을 가지는 단량체의 그라프트 중합은 LDPE 필름 표면에서 물과 같은 친수성 용매의 접촉각을 감소시키고, MMA와 같은 소수성 그룹을 가지는 단량체의 경우는 LDPE 필름 표면에서 methylene diiodide와 같은 비극성 용매의 표면 접촉각을 감소시켰다. 이는 AM 및 MMA 단량체의 그라프트 중합에 의한 것으로, LDPE 필름 표면은 친수성 및 소수성 용매에 대한 젖음성이 향상되었다.

SBR Latex의 개질 및 접착특성 (Modification of SBR Latex and its Adhesion Characteristic)

  • 김구니;전용철;오상택;박승현;이창호;유종선;민병권
    • Elastomers and Composites
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    • 제29권5호
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    • pp.444-452
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    • 1994
  • Emulsion graft copolymerizations of vinyl monomers, butyl acrylate(BA), methyl methacrylate(MMA), 2-ethylhexyl acrylate (EHA), glycidyl methacrylate (GMA), 2-hydroxyethyl methacrylate(HEMA), methacrylonitrile(MAN), dimethylaminoethyl methacrylate(DAMA) or 2-vinyl pyridine(VP), onto carboxyl-terminated SBR latex were carried out under different experimental conditions. In case of synthesizing SBR-g-poly(butyl acrylate), the degree of grafting was increased with increasing the amount of emulsifier, polymerization temperature and the amount of initiator. Pull-out strength of resorcinol-formaldehyde-latex(RFL) adhesives formulated with modified latexes was very higher than that of RFL adhesive formulated with ungrafted latex. When the modified latexes with GMA, HEMA, MAN, DAMA or VP were used, the break occurred at cords. Peel strength of RFL adhesives formulated with SBR-g-poly(GMA), SBR-g-poly(HEMA) or SBR-g-poly(VP) was higher by about 1.3 times than that of RFL adhesives formulated with unmodified SBR against nylon cord and was higher by about 2.0 times against polyester cord.

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선천성 흉벽질환의 교정 (Surgical Treatment of Congenital Chest Wall Defects)

  • 김주현
    • Journal of Chest Surgery
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    • 제20권1호
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    • pp.161-170
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    • 1987
  • Fifty-nine cases of congenital chest wall defects experienced in the department of thoracic surgery of Seoul National University Hospital were analyzed and the relevant literatures were reviewed. They are 52 cases of funnel chest, 3 cases of pigeon breast, one case of superior sternal fissure, one case of costochondral incurvation, one case of Cantrell`s pentalogy, and one case of Poland`s syndrome. Funnel chest affected males more frequently than females by 44 to 8. All of the funnel deformities were corrected by Ravitch operation or its modification except one which was the first case of this series and was corrected by a sterno-turnover. Two cases required a mechanical ventilation for 3 days and 5 days respectively. Four minor complications which were two cases of skin wound infection and 2 cases of fluid accumulation were noted. Skin would infection was repaired by a secondary closure and fluid accumulation was treated by aspiration only. The result are all excellent without recurrence or reoperation. In 3 cases of pigeon breast, they were treated by subperichondrial resection of all of the involved costal cartilages and shortening their course with reefing sutures in the perichondrium with excellent result. The superior sternal fissure which was combined by a ventricular septal defect was treated by a simple wire closure with a good result. The costochondral incurvation was corrected by subperichondrial resection of deformed cartilages and a rib graft removed from the contralateral normal side. The Poland syndrome and the Cantrell`s pentalogy was already presented previously.

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좌심저형성 증후군 경험 1 (Hypoplastic Left Heart Syndrome - Experience in one Patient -)

  • 장봉현
    • Journal of Chest Surgery
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    • 제20권2호
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    • pp.404-410
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    • 1987
  • An 18-day-old male neonate with hypoplastic left heart syndrome underwent surgical intervention by modification of the Norwood procedure on September 23, 1986. Hypoplastic left heart syndrome is a serious congenital cardiac anomaly that has a fatal outlook if left untreated. Included in this anomaly are [1] aortic valve atresia, and hypoplasia of the ascending aorta and aortic arch, [1] mitral valve atresia or hypoplasia, and [3] diminutive or absent left ventricle. Patent ductus arteriosus is essential for any survival, and there is usually a patent foramen ovale. Coarctation of the aorta is frequently associated with the lesion.z With a limited period of cardiopulmonary bypass, deep hypothermia, and circulatory arrest, the ductus arteriosus was excised. The main pulmonary artery was divided immediately below its branches, and the distal stump of the divided pulmonary artery was closed with a pericardial patch. The aortic arch was incised, and a 1 5mm tubular Dacron prosthesis was inserted between the main pulmonary artery and the aortic arch. A 4mm shunt of polytetrafluoroethylene graft was established between the new ascending aorta and the right pulmonary artery to provide controlled pulmonary blood flow. Following rewarming, the heart started to beat regularly, but the patient could not be weaned from cardiopulmonary bypass. At autopsy, the patient was found to have hypoplasia of the aortic tract complex with mitral atresia and aortic atresia. A secundum atrial septal defect was noted. Right atrial and ventricular hypertrophy was present, and the left ventricle was entirely absent. Although unsuccessful in this case report, continuing experience with hypoplastic left heart syndrome will lead to an improvement in result.

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방전처리에 의한 Polypropylene섬유의 표면개질 (Surface Modification of Polypropylene Fiber by Plasma Discharge)

  • 허만우;이창재;강인규;한명호;김삼수;임학상
    • 한국염색가공학회지
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    • 제11권2호
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    • pp.27-37
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    • 1999
  • Polypropylene(PP) films were treated with plasma glow discharge to produce peroxy radicals on the surfaces. The peroxy radicals formed on the PP film surfaces were subsequently used for the graft polymerization of acrylic acid and acrylamide in an aqueous solution by heating, respectively. Introduction of acrylic acid and acrylamide on the PP film could be confirmed by the observation of carbonyl and primary amine absorptions based on carboxylic acid and amide, respectively. And introduction of functional group could be confirmed by weight analysis and ESCA. The water contact angle(90$^{\circ}$) of PP film was constant, irrespective of elapsed time, while plasma-treated and functional monomer-grafted PP films were slowly increased with elapsed time, showing the rearrangement of surface polar groups in air condition. The water contact angle$(90^\circ)$ of PP film was decreased by the plasma treatment$(56^\circ)$ and further decreased by the grafting of acrylic acid$(34^\circ)$ and acrylamide$(37^\circ)$, indicating increased hydrophilicity of the modified surfaces. The water contact angle of plasma-treated PP film increased a little as time elapsing. The half-life periods of surface voltage on acrylic acid-(31sec) and acrylamide-grafted PP(42sec) were significantly decreased when compared to those on PP(950sec) and plasma-treated PP film(241sec). In the experiments using acid, basic and disperse dyes, absorbance and $\Delta{E}$ values of functional monomer-grafted PP films were significantly increased than that of oxygen plasma-treated one.

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당뇨병성 족부 궤양의 치료 (Management of Diabetic Foot Ulcer)

  • 서동교;이호승
    • 대한족부족관절학회지
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    • 제18권1호
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    • pp.1-7
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    • 2014
  • In patients with diabetic foot, ulceration and amputation are the most serious consequences and can lead to morbidity and disability. Peripheral arterial sclerosis, peripheral neuropathy, and foot deformities are major causes of foot problems. Foot deformities, following autonomic and motor neuropathy, lead to development of over-pressured focal lesions causing the diabetic foot to be easily injured within the shoe while walking. Wound healing in these patients can be difficult due to impaired phagocytic activity, malnutrition, and ischemia. Correction of deformity or shoe modification to relieve the pressure of over-pressured points is necessary for ulcer management. Application of selective dressings that allow a moist environment following complete debridement of the necrotic tissue is mandatory. In the case of a large soft tissue defect, performance of a wound coverage procedure by either a distant flap operation or a skin graft is necessary. Patients with a Charcot joint should be stabilized and consolidated into a plantigrade foot. The bony prominence of a Charcot foot can be corrected by a bumpectomy in order to prevent ulceration. The most effective management of the diabetic foot is ulcer prevention: controlling blood sugar levels and neuropathic pain, smoking cessation, stretching exercises, frequent examination of the foot, and appropriate education regarding footwear.

전자선을 이용한 아크릴산 그라프트 케냐프 섬유의 제조 및 이를 이용한 케냐프 섬유보강 시멘트의 투수특성 평가 (Preparation of Acrylic Acid-grafted Kenaf Fibers Using E-beam Irradiation and Evaluation of Permeability of Kenaf Fiber-cement Composites)

  • 김두영;전준표;김현빈;오승환;강필현
    • 방사선산업학회지
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    • 제8권1호
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    • pp.53-57
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    • 2014
  • The kenaf is quickly developing as a renewable resource. Kenaf can be grown under a wide range of weather conditions. Modification of kenaf fiber by graft polymerization provides a significant route to alter the chemical properties, including surface hydrophilicity or hydrophobicity. In this study, kenaf fiber surfaces were grafted with acrylic acid as a hydrophilic group using electron beam irradiation. The grafting rate increased with an increase in grafting time. The FT-IR results confirmed that acrylic acid was successfully grafted onto the kenaf fibers. The wettability of the kenaf fiber was increased, accompanied by acylic acid grafting on the fiber surface. According to the permeability test result, it was found that acrylic acid grafted kenaf fiber reinforced cement composite was more reduced than non-grafted kenaf fiber reinforced cement composite.