• 제목/요약/키워드: Grafting

검색결과 1,533건 처리시간 0.029초

Polycyclotriphosphazene Derivative Grafted and NanometerY2O3 Doped SPEEK Composite Membrane for DMFC

  • Li, Xia;Guo, Qiang;Zhang, Tianjiao;Qian, Junzhi;Tan, Xiaolin
    • 대한화학회지
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    • 제57권5호
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    • pp.625-633
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    • 2013
  • A type of polycyclotriphosphazene derivative (PCTPD), hexasulfanilic acid polycyclotriphosphazene (HSACP) and HSACP grafting SPEEK, sulfonated poly[2-(petachloropolycyclotriphosphazene-oxy)] etheretherketone (SPPSACPEEK) were synthesized, which were characterized by FTIR and $^{31}P$ NMR. Then three types of composite membranes such as HSACP grafting SPEEK, HSACP blending SPEEK, and nano $Y_2O_3$ doping and HSACP grafting SPEEK, respectively, were continuously prepared by solution-casting method. Comparing to SPEEK membranes with different amount of HSACP grafted or blended, grafting 15 wt% HSACP and doping 10 wt% nano $Y_2O_3$ SPEEK membrane conducted outstanding overall behavior of proton conductivity reaching $3.18 {\times}10^{-2}$ S/cm at $90^{\circ}C$ which was merely junior to SPEEK with 15 wt% HSACP grafted, methanol permeability coefficient getting $9.46{\times}10^{-8}cm^2{\cdot}s^{-1}$, swelling degree of 20.9% and solid residue of 98.98% which was superior to all specimen.

Natural Rubber-polyacrylamide Graft 공중합체의 합성 (Synthesis of Natural Rubber-g-polyacrylamide Polymer)

  • Son, Cha Hoo;Kim, Kyung Hwan;Park, Tchun Wook
    • 한국염색가공학회지
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    • 제7권4호
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    • pp.45-53
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    • 1995
  • Natural rubber(NR)-polyacrylamide(PAAm) graft copolymers(GP)(toluene soluble GP : TSGP, water dispersible GP : WDGP) have been synthesized as coupling agents by pre-emulsification methods based on "inverse emulsion graft polymerization" technique. The polymerization was carried out at $65^{\circ}C$ using Azobisisobytyro nitrile(AIBN) as an initiator in the inverse emulsion system formed by inxing NR toluene solution with inverse emulsion of awueous AAm solution emulsified with $Tween^{\#}$ 80 in toluene. The mechanism of inverse emulsion graft copolymerization was studied on AAm conversion, % grafting, grafting efficiency, NR conversion, production ratio of TSGP and amount of GP(sum of TSGP and WDGP). The reaction has been confirmed through use of optical microscope to proceed via adsorption of emulsifier colloid particles onto the stretched NR molecule. From the analysis of the effects of various polymerization conditions on the grafting, it has also been found that the present rection system can easily yield high(over 90%) grafting efficiency and AAm conversion and relatively high(over 80%) NR conversion.onversion.

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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.

폴리프로필렌에 UV 흡수제를 갖는 말레이미드의 용융그래프팅 (Thermal Melt Grafting of Maleimides Having UV-absorber onto Polypropylene)

  • 김택현;나혜선
    • 폴리머
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    • 제38권1호
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    • pp.49-53
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    • 2014
  • 새로운 단량체형의 자외선흡수제를 triethylamine에서 2,4-dihydroxybenzophenone과 N-4-chlorocarbonyl-phenylmaleimide의 반응을 통하여 합성하였다. 이 자외선흡수제를 폴리프로필렌에 용융반응에 의해 그래프팅하였다. Maleimide의 그래프팅 수율은 IR 분광 데이터를 이용하여 결정하였다. 용융반응의 최적조건을 구하기 위하여 반응온도 및 시간, 단량체의 농도의 변화에 대하여 그래프팅 수율을 구하였다. Weatherometer에서 IR 스펙트럼의 카보닐 지수를 이용하여 그래프트된 폴리프로필렌의 광산화 정도를 조사하였으며, 우수한 광산화 억제작용을 보였다.

구순구개열환자에서 자가입자망상골을 이용한 이차성 치조골이식에 관한 임상적 연구 (CLINICAL STUDY OF AUTOGENOUS SECONDARY BONE GRAFTING IN CLEFT MAXILLA)

  • 김종렬;진성준;조영철;표세정;변준호
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제23권2호
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    • pp.163-168
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    • 2001
  • Purpose : This study is conducted to evaluate the clinical success of secondary alveolar bone grafting using autogenous iliac particulate cancellous bone marrow in cleft maxilla. Materials and methods : We evaluated 107 cleft patients who had been admitted to the Dept. of Oral and Maxillofacial Surgery of Pusan National University Hospital from January 1, 1991 to January 31, 1999 and had been performed secondary alveolar bone grafting with autogenous particulated cancellous bone marrow from iliac crest. Results : 1. Men were 70 and women were 37, which shows 65.4% and 34.6% and the proportion of males to females was 1.9:1. Unilateral cases were 89(83.2%) and bilateral cases were 18(16.8%). 2. Age of bone grafting is widely distributed from 7 to 29, and the average was 13.2. 3. Success rate was 97.8% in unilateral cases, 94.4% in bilateral cases. Overall success rate was 96.7%. 4. We evaluated the bone graft contour by the percentage of bone attachment level adjacent to the alveolar cleft and the menial side showed 82.4% and the distal 87.7%. 5. The amount of notching the alveolar ridge at the grafted site through the ratio of notching length up to the most apical base to the length of proximal segment anatomic root was 0.19.

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상악동골이식 후 임플란트 생존율 및 골이식재의 흡수율에 관한 임상적 연구 (Clinical Study on Implant Survival and Graft Resorption Rate After Maxillary Sinus Bone Grafting)

  • 이재환;지영덕;민승기;오승환;권대근;전인철
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제32권6호
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    • pp.529-536
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    • 2010
  • Purpose: The Purpose of this study is to show the total survival rate of implants with maxillary sinus grafting and the effects that reach the survival rate by classifying types of graft materials, implant type, operation method, residual bone height and evaluate graft material resorption rate after sinus grafting Patients and Methods: 61 dental implants placed with sinus bone grafting in 24 patients at Wonkwang University Sanbon Dental Hospital were installed simultaneously or after regular healing. Various bone grafts (autograft, xenograft, allograft, alloplast) and fourth implant type (GSII, Xive, Implantium, Novel biocare) were used. All implants were investigated clinically and radiographically, being with average 20 months follow-up period after installation. Results: 3 fixtures were lost, resulting in 95.1% cumulative survival rate of 61 osseointegrated dental implant. Survival rate according to bone material type, Implant type, operation method, residual bone height, have no statistically significant differencies. The mean preoperative residual alveolar bone height was 4.75 mm, average postoperative height of graft materials 10.8 mm, vertical bone resorption rate was 10% after 2 years. Resorption rate according to operation method was 7% (simultaneous) and 5% (delayed) after 1 year. Conclusion: It can be suggested that maxillary sinus grafting may have predictable result with various bone graft materials and implant type, residual bone height, operation method

Anterior Interbody Grafting and Instrumentation for Advanced Spondylodiscitis

  • Lim, Jae-Kwan;Kim, Sung-Min;Jo, Dae-Jean;Lee, Tae-One
    • Journal of Korean Neurosurgical Society
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    • 제43권1호
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    • pp.5-10
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    • 2008
  • Objective : To evaluate the surgical outcomes of ventral interbody grafting and anterior or posterior spinal instrumentation for the treatment of advanced spondylodiscitis with patients who had failed medical management. Methods : A total of 28 patients were evaluated for associated medical illness, detected pathogen, level of involved spine, and perioperative complications. Radiological evaluation including the rate of bony union, segmental Cobb angle, graft- and instrumentation-related complications, and clinical outcomes by mean Frankel scale and VAS score were performed. Results : There are 14 pyogenic spondylodiscitis, 6 postoperative spondylodiscitis, and 8 tuberculous spondylodiscitis. There were 21 males and 7 females. Mean age was 51 years, with a range from 18 to 77. Mean follow-up period was 10.9 months. Associated medical illnesses were 6 diabetes, 3 pulmonary tuberculosis, and 4 chronic liver diseases. Staphylococcus was the most common pathogen isolated (25%), and Mycobacterium tuberculosis was found in 18% of the patients. Operative approaches, either anterior or posterior spinal instrumentation, were done simultaneously or delayed after anterior aggressive debridement, neural decompression, and structural interbody bone grafting. All patients with neurological deficits improved after operation, except only one who died from aggravation as military tuberculosis. Mean Frankel scale was changed from $3.78{\pm}0.78$ preoperatively to $4.78{\pm}0.35$ at final follow up and mean VAS score was improved from $7.43{\pm}0.54$ to $2.07{\pm}1.12$. Solid bone fusion was obtained in all patients except only one patient who died. There was no need for prolongation of duration of antibiotics and no evidence of secondary infection owing to spinal instrumentations. Conclusion : According to these results, debridement and anterior column reconstruction with ventral interbody grafting and instrumentation is effective and safe in patients who had failed medical management and neurological deficits in advanced spondylodiscitis.

Resistance of Cucumber Grafting Rootstock Pumpkin Cultivars to Chilling and Salinity Stresses

  • Xu, Yang;Guo, Shi-rong;Li, He;Sun, Hong-zhu;Lu, Na;Shu, Sheng;Sun, Jin
    • 원예과학기술지
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    • 제35권2호
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    • pp.220-231
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    • 2017
  • Grafting using a pumpkin (Cucurbita sp.) rootstock is an effective way to improve cucumber (Cucumis sativus) resistance to a combination of chilling and salinity stresses. We evaluated the tolerance of 15 pumpkin cultivars to chilling, salinity, and combined stresses at the germination and seedling stages. Selected plant characteristics, including germination rate, germination potential, germination index, plant height, stem thickness, fresh weight, and dry weight, were analyzed. We used the unweighted pair group method with arithmetic mean for cluster analyses to determine the stress tolerance levels of the pumpkin cultivars. The 15 cultivars were divided into three clusters: tolerant, moderately tolerant, and susceptible to stress treatments. The stress tolerances of all cultivars were variable in the germination and seedling stages, and most cultivars were not tolerant to individual treatments of chilling or salinity stresses at both stages. These results suggest that identifying suitable cultivars for use as rootstock during cucumber grafting should involve the evaluation of stress tolerance during different growth stages. Additionally, cultivars tolerant to chilling stress may not be tolerant to salinity stress; therefore, the choice of pumpkin rootstock should depend on where the grafted plant will be grown. Cultivars tolerant to a combination of chilling and salinity stresses may be useful as rootstock for cucumber grafting. Our findings may serve as reference material for choosing appropriate pumpkin rootstocks for cucumber grafting.

Feasibility of the Use of RapiGraft and Skin Grafting in Reconstructive Surgery

  • Yang, Jung Dug;Cho, In Gook;Kwon, Joon Hyun;Lee, Jeong Woo;Choi, Kang Young;Chung, Ho Yun;Cho, Byung Chae
    • Archives of Plastic Surgery
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    • 제43권5호
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    • pp.418-423
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    • 2016
  • Background Skin grafting is a relatively simple and thus widely used procedure. However, the elastic and structural quality of grafted skin is poor. Recently, various dermal substitutes have been developed to overcome this disadvantage of split-thickness skin grafts. The present study aims to determine the feasibility of RapiGraft as a new dermal substitute. Methods This prospective study included 20 patients with partial- or full-thickness skin defects; the patients were enrolled between January 2013 and March 2014. After skin defect debridement, the wound was divided into two parts by an imaginary line. Split-thickness skin grafting alone was performed on one side (group A), and RapiGraft and split-thickness skin grafting were used on the other side (group B). All patients were evaluated using photographs and self-questionnaires. The Manchester scar scale (MSS), a chromameter, and a durometer were used for the scar evaluation. The average follow-up period was 6 months. Results The skin graft take rates were 93% in group A and 89% in group B, a non-significant difference (P=0.082). Statistically, group B had significantly lower MSS, vascularity, and pigmentation results than group A (P<0.05 for all). However, the groups did not differ significantly in pliability (P=0.155). Conclusions The present study indicates that a simultaneous application of RapiGraft and a split-thickness skin graft is safe and yields improved results. Therefore, we conclude that the use of RapiGraft along with skin grafting will be beneficial for patients requiring reconstructive surgery.

Growth and Development of Grafted Cucumber Transplants as Affected by Seedling Ages of Scions and Rootstocks and Light Intensity during Their Cultivation in a Closed Production System

  • Kwack, Yurina;Park, Seon Woo;Chun, Changhoo
    • 원예과학기술지
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    • 제32권5호
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    • pp.600-606
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    • 2014
  • The objective of this study was to determine the effects of seedling ages of scions and rootstocks for grafting and light intensity during their cultivation in a closed transplant production system on the growth and development of grafted cucumber transplants. Cucumber scions and rootstocks were cultivated under 5 photosynthetic photon flux (PPF) levels: 100, 140, 180, 230, and $280{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in a closed transplant production system. The scions were grafted onto the rootstocks at 8, 9, 10, 11, and 12 days after sowing (DAS). Hypocotyl length of scions and rootstocks decreased significantly as PPF increased, and an increase in dry weight with increasing PPF was more pronounced in scions. After grafting, cucumber transplants were grown in a greenhouse until 22 DAS and were then transplanted for investigation of their growth and development. Plant height, leaf area, and fresh weight of cucumber transplants grafted at 8, 9, and 10 DAS were greater, but light intensity during cultivation of scions and rootstocks did not significantly affect the early growth of cucumber transplants after grafting. The number of female flowers in grafted cucumber after transplanting was highest when scions and rootstocks were cultivated under PPF 140 and $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and were grafted at 8 DAS. These results indicate that controlling environmental conditions in a closed transplant production system during the production of scions and rootstocks can advance grafting time and promote the growth and development of grafted cucumber transplants.