• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.358-358
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• 2006

The graft copolymerization of methyl methacrylate (MMA), butyl acrylate (BA) and acrylamide (AAm) onto oil palm empty fruit bunch (OPEFB) fiber were successfully carried out in aqueous solution using $H_{2}O_{2}/Fe^{2+}$ as initiator. For all monomers the percentage of grafting increases with the amount of monomer and can be controlled by setting the appropriate reaction conditions. The optimum reaction period were found to be 120 minutes for all monomers whereas the optimum temperature and the amount of initiator needed for grafting depend on the type of the monomer used. The mechanisms of grafting vinyl monomer onto OPEFB were proposed. The grafted products were characterized by gravimetric analysis, FTIR and SEM.

• Nuclear Engineering and Technology
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• 제52권2호
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• pp.373-380
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• 2020

This study was carried out to convert the hydrophobic characteristics of PVDF to hydrophilic. Poly(-vinylidene fluorine) (PVDF) was grafted by electron beam irradiation and sulfonated. The grafting degree of modified PVDF increased with the monomer concentration, but not the conversion degree. From the results of FTIR and XPS, it was shown that the amount of converted sulfur increased with the grafting degree. The radiation-induced graft polymerization led to decrease fluorine from 35.7% to 21.3%. Meanwhile, the oxygen and sulfur content increased up to 8.1% and 3.2%. The pore size of modified membranes was shrunken and the roughness sharply decreased after irradiation. The ion exchange capacity and contact angle were investigated to show the characteristics of PVDF. The enhanced ion exchange capacity and lower contact angle of modified PVDF showed that the hydrophilicity played a role in determining membrane fouling. Electron beam irradiation successfully modified the hydrophobic characteristics of PVDF to hydrophilic.

• Archives of Plastic Surgery
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• 제50권1호
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• pp.26-29
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• 2023

Cryptotia is a rare congenital auricular deformity among Caucasians but more common in Asians. Various operative techniques have been described, such as skin graft, V-Y plasty, Z plasty, and islands skin flap. Among those techniques, V-Y plasty has many advantages and is indicated for severe cases. However, several problems remain when this method is adopted, such as conspicuous scars and lowered hairline. To overcome these problems, the authors have developed a new technique, multiple V-Y advancement modification, which stitches the skin flaps together to a tight, discrete central focal point. This technique has the advantage of hiding scars behind the earlobe, providing enough skin for the deformed areas, minimizing the condition of the hairline being lowered and auriculocephalic sulcus depth.

• Archives of Plastic Surgery
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• 제32권1호
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• pp.117-123
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• 2005

The reconstructive modalities for vaginal reconstruction include simple dilatation, skin graft, use of intestinal segments and various methods using flaps. However, skin grafting procedure is the most commonly used technique and the McIndoe procedure is a representative technique among skin grafting procedures. McIndoe procedure is easier, faster and has a lower morbidity compared to other techniques. However the conventional McIndoe procedure has several problems such as incomplete vestibule formation, excessive bleeding during dissection, possibility of recto-vaginal or urethro-vaginal fistula formation, late vaginal contracture and discomfort in wearing hard plastic mold for a long time after operation. To solve these problems, the authors modified the conventional McIndoe procedure in several perspectives. The undeveloped vestibule was incised with X-shaped mucosal incision between the urethral opening and posterior margin of the vestibule and deepened by blunt finger dissection to provide a sufficient diameter & length of the neovagina and to minimize bleeding. A sizable medium thickness split skin graft was harvested and wrapped over a roll gauze-filled condom mold. Applying multiple stab incision on the skin grafted condom mold, it was inserted into the prepared neovaginal canal. Distal margin of the skin graft was secured with tips of the mucosal flaps created by X-shaped vestibular incision to prevent accidental extrusion of the skin grafted mold. During last 15 years, we applied this modification to 20 vaginal agenesis patients and investigated results of the 12 patients who could be followed up serially including hematoma formation and skin graft survival rate, size, depth, presence of late contracture, appearance, comfortness, and hygiene of the neovagina. And they were compared with 8 patients of 20 patients who underwent conventional McIndoe procedures. The modified McIndoe procedure revealed lower complication rate, higher patient satisfaction and better functional results.

• Journal of Chest Surgery
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• 제34권9호
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• pp.720-723
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• 2001

우관상동맥 폐쇄증을 동반한 Marfan 증후군환자를 보고한다. 환자는 45세 여자로 약 1년 전에 Marfan 증후군으로 진단받고, 최근 흉통을 주소로 내원하였다. 환자는 손가락과 발가락이 긴 지주증과 돌출흉이 있고 몸통에 비해 사지가 긴 전형적인 외형을 갖고 있었다. 시력이 매우 약하고 수정체의 아탈구가 있었다. 심초음파상 대동맥판막 폐쇄부전증은 경도로 있었고, 좌심실의 중등도 확장과 심박출율의 중등도 저하가 있었다. 수술시에 우관상동맥의 폐쇄증을 발견하였다. 대동맥판막 폐쇄부전증과 대동맥 확장증에 대해서 SJM 27mm composite graft를 이용하여 좌관상동맥에는 Bentall 술식과 우관상동맥에는 PTFE 6mm를 이용하여 변형된 Piehler 식 방법으로 수술을 하였다. 원래의 우관상동맥구로 추정되는 부분부터 우관상동맥 원위부의 혈류가 있는 곳까지의 결손부위는 약 4cm 가량 되었다. 관상동맥 폐색증과 Marfan 증후군의 조합은 매우 드문 질환으로 양측 관상동맥의 혈류 재건을 위하여 각기 다른 술식으로 수술하였다.

• Journal of Periodontal and Implant Science
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• 제53권6호
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• pp.417-428
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• 2023

Purpose: To investigate the effect of xenogeneic collagen matrix (XCM) with polydeoxyribonucleotide (PDRN) for gingival phenotype modification compared to autogenous connective tissue graft. Methods: Five mongrel dogs were used in this study. Box-type gingival defects were surgically created bilaterally on the maxillary canines 8 weeks before gingival augmentation. A coronally positioned flap was performed with either a subepithelial connective tissue graft (SCTG) or XCM with PDRN (2.0 mg/mL). The animals were sacrificed after 12 weeks. Intraoral scanning was performed for soft tissue analysis, and histologic and histomorphometric analyses were performed. Results: One animal exhibited wound dehiscence, leaving 4 for analysis. Superimposition of STL files revealed no significant difference in the amount of gingival thickness increase (ranging from 0.69±0.25 mm to 0.80±0.31 mm in group SCTG and from 0.48±0.25 mm to 0.85±0.44 mm in group PDRN; P>0.05). Histomorphometric analysis showed no significant differences between the groups in supracrestal gingival tissue height, keratinized tissue height, tissue thickness, and rete peg density (P>0.05). Conclusions: XCM soaked with PDRN yielded comparable gingival augmentation to SCTG.

• 공업화학
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• 제5권4호
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• pp.698-705
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• 1994

Linseed oil fatty acid(LOFA), phthalic anhydride(PAA) 및 maleic anhydride(MA), trimethylol propane(TMP)을 사용하여 기본적인 유장(oil length) 50%의 중유성 기본 알키드를 합성하고 trimethylol propane triacrylate(TMPTA)를 그라프트 공중합시켜 MA/TMPTA 변성 알키드 수지를 제조하였다. 수지의 산가는 MA 첨가량으로 제어하였으며, 수용화에는 N,N-dimethylethanol amine(DMEA)를 사용하였다. TMPTA의 첨가량 변화에 의한 분자량, 유리 전이온도, 수용화 후의 점성도 및 그라프트율을 측정하였으며, 가교도막의 경화온도별 겔분율 변화를 조사하였다. 또한 멜라민 수지 경화 도막의 내열성, 내자외선성, 내수성 및 저장 안정성을 측정하고, TMA/TMPTA 변성 알키드 수지의 물성과 비교하였다. TMPTA의 첨가량이 증가할수록 수용화 후의 점성도, 겔분율, 그라프트율 및 분자량이 증가하였으며, 유리 전이온도(Tg)는 감소하였다. 고형분 함량에 따른 점성도 변화는 고형분 30%일 때보다 40%일 때가 더 낮게 나타났으며, 중화도에 따른 점성도 변화는 중화도가 높을수록 낮은 점성도를 나타내썼다. 내열성, 내자외선성, 내수성은 MA/TMPTA 변성 알키드 수지가 TMA/TMPTA 변성 알키드 수지보다 우수하였으나, 저장 안정성은 TMA/TMPTA 변성 알키드 수지가 우수함을 알 수 있었다.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2011년도 제44차 학술발표회
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• pp.31-31
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• 2011

Lanasol dyes containing ${\alpha}$-bromoacrylamide or ${\alpha},{\beta}$-dibromopropionylamide group are used for wool dyeing. They are normally applied to wool under pH 4.5 to 6.5 at $100^{\circ}C$. Although wool fabric can be dyed to obtain deep colour, high light and wet fastness, the dyeing processes need long dyeing time at high temperature, with salt addition, which inevitably causes environmental problems. Grafting is a modification method for textile where monomers are covalently bonded onto the polymer chain. It can be initiated by ozone, ${\gamma}$ rays, electron beams, plasma, corona discharge and UV irradiation. Coloration by UV-induced photografting exhibits several advantages such as fast reaction rate, energy saving, simple equipment, easy exploitation and environmentally friendliness. Also it requires much lower energy compared to the conventional dyeing and less damage to the substrate. In this study, a direct sequential UV-induced photografting onto wool fabrics was discussed. To understand the graft polymerization mechanism further, several characterization methods were used. Moreover, the effects of several principal factors on the graft photopolymerization were investigated. Furthermore, the colorfastness results were compared with conventional dyeing methods.

• 폴리머
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• 제34권2호
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• pp.126-132
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• 2010

메탄올 용매에서 고분자 촉진 단량체와 소디윰 스티렌 슐포네이트를 방사선 그래프트 방법으로 양이온 교환 PVdF 맴브레인을 제조하였다. 고분자 촉진 단량체로서 스티렌, 아크릴산, 비닐 피롤리돈을 사용하였다. 또한, 음이온 교환 PVdF 맴브레인도 방사선 그래프트 중합법에 의해 제조하였다. 양이온 및 음이온 교환 PVdF 맴브레인은 SEM, XPS 그리고 열분석기기를 통해 특성평가를 하였고 성공적으로 합성됨을 확인할 수 있었다. 그래프트 수율, 이온교환기의 양 및 침투율은 각각 30.0~32.3%, 2.81~3.01 mmol/g 그리고 66.6~147%로 평가되었으며, 20 $^{\circ}C$에서 이온 전도도를 측정한 결과 0.020~0.053 S/cm 이었다. 최종적으로, 제조된 양이온 및 음이온교환 PVdF 맴브레인은 전지격막으로서 충분히 사용될 수 있음을 확인할 수 있었다.

• Archives of Reconstructive Microsurgery
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• 제14권2호
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• pp.117-124
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• 2005

Purpose: To present our experience and design modification of an anterolateral thigh flap in soft tissue reconstruction. Materials and Methods: Between April of 2004 and May of 2005, 26 anterolateral thigh flaps were used in 26 patients. There were 22 males and 4 females between 23 and 60 years (mean, 40years). The mean follow-up period was 11($4{\sim}18$) months. All cases were a cutaneous flap. Twenty-two were musculocutaneous perforator flaps(85%) and 4 were septocutaneous perforator flaps(15%). Four flaps were used as a sensate flap. While the donor sites were closed directly in 14 cases(54%), 12 cases(46%) underwent skin grafting of the donor site. During the flap design, a triangular skin design was added to a vascular anastomosis site in 14(54%) patients and used as a roof of the tunnel. The healing period of the skin graft between those performed above the fascia and above the muscle were compared. Results: The average size of the flaps was $16{\times}9(11-20{\times}7-12)\;cm$. The overall flap success rate was 96%. Complications encountered were infection in 4 cases, and marginal skin necrosis in 1 case. The healing period was delayed with the infection in 3 of the 6 cases involving a skin graft over the fascia. All 14 cases with the triangular skin design survived, but there was 1 flap failure and 1 marginal necrosis in 12 cases without a triangular skin design. Conclusions: It may be better to undergo a skin graft above the muscle than above the fascia in covering a donor site defect, and to use a triangular skin design in order to prevent vascular insufficiency. An anterolateral thigh flap is a versatile flap for a soft tissue reconstruction because its thickness and volume can be adjusted to the extent of the defect with minimal donor site morbidity.