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Graft Polymerization of Methyl Methacrylate onto Cotton Fiber -Comparison of two step graft polymerization and emulsion graft polymerization- (면섬유에 Methyl Methacrylate의 그라프트중합 - 이단계 그라프트중합과 유화 그라프트중합의 비교 -)

  • Bae Hyun-Sook;Kim Sung-Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.13 no.1
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    • pp.89-97
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    • 1989
  • Graft polymerization of MMA onto cotton fiber was carried out in two ways, two step graft polymerization and one step emulsion graft polymerization, using tetravalent cerium ion as an initiator. At two step graft polymerization, the first step was the pretreatment of cotton fiber with an aqueous initiator solution and the second was the grafting pretreated cotton fiber in the monomer solution. In case of one step emulsion graft polymerization, MMA was emulsified with SLS in initiator solution. Under the various graft polymerization conditions, graft yield, graft efficiency and from the Arrhenius plot the apparent activation energy were compared. The results of this study were as follows: 1. Graft yield and graft efficiency of emulsion graft polymerization were higher than those of two step graft polymerization. 2. In case of two step graft polymerization, graft yield was affected by the pretreatment time of cotton fiber with an aqueous initiator solution. And graft yield of emulsion graft polymerization was increased with the concentration of emulsifier below cmc of SLS and was decreased thereafter. 3. Elevation of temperature resulted increase in graft yield for both grafting methods. The apparent activation energy of emulsion graft pelymerzation was lower than that of two step graft polymerization. 4. Increased reaction time increased in graft yield, but decreased in graft efficiency. 5. Moisture regain of grafted cotton was decreased with graft yield.

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Effective grafting method for Korean jujube nursery tree

  • Park, Hee-Seung;Kim, Yong-Koo;Chung, Kyu-Hwan;Ahn, Young-Hee
    • Journal of Environmental Science International
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    • v.12 no.2
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    • pp.119-124
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    • 2003
  • An effective grafting method for jujube nursery trees was developed to shorten the operation time, improve the percentage of "takes" and shoot emergence, and form the better graft union. Out of 7 grafting methods the splice, modified scion Ono graft and the bark graft showed relatively short operation time during the grafting operation comparing to the modified rootstock Ono graft or the chip budding. Among these methods, the bark graft demonstrated 100% "takes", but the modified scion Ono graft or the standard Ono graft showed 58.3% of "takes". The percentages of the vegetative shoot emergence were 100% fir the bark graft, 70% f3r the modified scion Ono graft and lower emergence percent for the rest grafting methods. The union tissue formation for the modified scion Ono graft, the bark graft, or the whip-and-tongue graft was significantly larger than the standard Ono graft or the splice graft. In a close examination of the cross sectional areas of the graft union formation through the microscope, the bark graft was superior, the standard Ono graft was inferior and rest of the grafting methods were intermediate.ing methods were intermediate.

Studies of Graft Polymers (I). Graft Site Distribution of Anionic Polymer (고분자 결합에 관한 연구 (제1보). Anionic Polymer의 Graft Site 분포)

  • Chul Yung Cha
    • Journal of the Korean Chemical Society
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    • v.20 no.4
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    • pp.251-259
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    • 1976
  • Graft site distribution of graft polymer was derived from a statistical model. Theoretical model was experimentally confirmed by preparing well defined graft polymer and using gel permeation chromatography(GPC). The results indicate that metalation of substrate polymer is statistically random process and anionic graft reaction products consist of ungrafted free side chain homopolymer; graft polymer with different number of graft chains and free backbone molecules when the averaged in the graft sites are small.

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VEIN GRAFT REPAIR COMPARED WITH NERVE GRAFTING FOR INFERIOR ALVEOLAR NERVE REGENERATION IN RABBITS (가토 하치조신경 재건에 있어 정맥이식통로를 이용한 신경재생유도에 관한 실험적 연구)

  • Shin, Il;Kim, Myung-Jin;Nam, Il-Woo
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.26 no.3
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    • pp.270-278
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    • 2000
  • This study was conducted to compare the vein graft with the nerve graft, and evaluated the availability of the vein graft on the reconstruction of the inferior alveolar nerve defect. The experimental animals were 12 rabbits weighing $1.5{\sim}2.0kg$, divided into 3 groups : sham operation group, vein conduit group and nerve graft group. All nerves were excised and histomorphometric analysis was performed at 2, 4, 6, 12, 16 weeks after operation. The obtained results were as follows. 1. Histologic examination revealed the regenerated nerve fibers within the lumen of the vein graft and nerve graft at 6 weeks after repair. 2. Axon diameter was significantly larger in nerve graft group(p<0.05) than in vein graft group at 6weeks, and larger in nerve graft group than in vein graft group at 16weeks. 3. Axon density was higher in the vein graft group at 16 weeks. 4. The myelin of the regenerated nerve fibers in distal segment of the vein graft group was thick, approaching the proximal segment at 16weeks. This means remyelination in distal segment in the vein graft group. These results suggested that autogenous vein graft may be used as an alternative to autogenous nerve graft.

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Alveolar Cleft Reconstruction Using Chin Bone and Autogenous Tooth Bone Graft Material: Reports of 5 Cases

  • Jeong, Kyung-In;Lee, Junho;Kim, Kyung-Wook;Um, In-Woong;Hara, Shingo;Mitsugi, Masaharu;Kim, Young-Kyun
    • Journal of Korean Dental Science
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    • v.6 no.1
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    • pp.13-21
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    • 2013
  • Purpose: To report the successful results of using chin bone graft and autogenous tooth bone graft material (AutoBT) in alveolar cleft patients. Materials and Methods: Five patients with alveolar cleft defects underwent alveolar bone grafting. Three patients were treated using chin bone graft, and the other two patients underwent AutoBT graft. After implant site development using chin bone graft in the fi rst three cases, endosseous implant restorations were placed. In case #4 and 5, AutoBT graft material was placed to guide the normal eruption of partially impacted maxillary right canine and to the upper docking site after distraction osteogenesis. Result: Successful implant restorations with closure of the oronasal fistula were achieved in alveolar cleft defect reconstruction using either chin bone graft (Case #1, 2, 3) or AutoBT graft material (Case #4, 5). Case #4 showed enlarged follicle of the right maxillary canine, indicating a normal eruption guide pattern. Conclusion: Both chin bone graft and AutoBT graft showed favorable outcomes in reconstructing alveolar cleft defects. Autogenous tooth bone graft opens up the possibility of avoiding harvesting autogenous bone graft with complications and morbidities.

Sericin- Fixation of Raw Silk by Graft Copolymerization (Graft 공중합에 의한 생사 Sericin 정착)

  • 김신덕
    • Journal of Sericultural and Entomological Science
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    • v.20 no.2
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    • pp.40-44
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    • 1978
  • Cerium (IV) ion-initiated graft copolymerizations of acrylonitrile to raw silk were investigated in an effort to carry out sericine-fixation. The change in ceric ammonium nitrate concentration exhibited a maximum in percentage of grafting at 0.003M. Also observed was that the change in nitric acid content in reaction media gave a maximum in percentage of grafting at 0.1M. Percentage of grafting was increased generally with increase in acrylonitrile concentration, reaction time and reaction temperature. Raw silk sericin grafted with acrylonitrile was not de gummed by boiling off test and optimum graft percentage was considered at 20%.

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The Study on the Gragting Rate MAA onto Silk Fiber by Redox System (Redox계에 의한 MAA Gragt 속도에 관한 연구)

  • 배도규;김종호
    • Journal of Sericultural and Entomological Science
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    • v.39 no.1
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    • pp.62-66
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    • 1997
  • The MAA graftings in silk fiber were done by redox system for the purpose of investingating the effect of ferrous sulfate additive on the grafting rate and graft ratio in various conditions. The graft ratio was higher in redox graft system than in peroxide graft system and the graft ratio in redox graft system was also higher depending on decrease of ferrous sulfate additive. The saturation graft ratio obtained by empirical equation, log X=K/t, was increasing depending on the increase of ferrous sulfate additive. Initial grafting rate was increased but the latter grafting rate was decreased in redox graft system. The effects of liquor ratio(L.R.) on the graft ratio in redox graft system, were higher in high L.R. than in low L.R..

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USEFULNESS OF ACELLULAR DERMAL MATRIX GRAFT ON THE TISSUE REGENERATION IN RABBITS (가토에서 조직 재생 이식재로서 무세포성 진피 기질의 효용)

  • Choi, Jong-Hak;Ryu, Jae-Young;Ryu, Sun-Youl
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.2
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    • pp.220-229
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    • 2008
  • Purpose: The present study was aimed to examine the effect of acellular dermal matrix ($AlloDerm^{(R)}$) grafted to the experimental tissue defect on tissue regeneration. Materials and Methods: Male albino rabbits were used. Soft tissue defects were prepared in the external abdominal oblique muscle. The animals were then divided into 3 groups by the graft material used: no graft, autogenous dermis graft, and $AlloDerm^{(R)}$ graft. The healing sites were histologically examined at weeks 4 and 8 after the graft. In another series, critical sized defects with 8-mm diameter were prepared in the right and left iliac bones. The animals were then divided into 5 groups: no graft, grafted with autogenous iliac bone, $AlloDerm^{(R)}$ graft, $AlloDerm^{(R)}$ graft impregnated with rhBMP-2, and $AlloDerm^{(R)}$ graft with rhTGF-${\beta}1$. The healing sites of bone defect were investigated with radiologic densitometry and histological evaluation at weeks 4 and 8 after the graft. Results: In the soft tissue defect, normal healing was seen in the group of no graft. Inflammatory cells and foreign body reactions were observed in the group of autogenous dermis graft, and the migration of fibroblasts and the formation of vessels into the collagen fibers were observed in the group of $AlloDerm^{(R)}$ graft. In the bone defect, the site of bone defect was healed by fibrous tissues in the group of no graft. The marked radiopacity and good regeneration were seen in the group of autogenous bone graft. There remained the traces of $AlloDerm^{(R)}$ with no satisfactory results in the group of $AlloDerm^{(R)}$ graft. In the groups of the $AlloDerm^{(R)}$ graft with rhBMP-2 or rhTGF-${\beta}1$, there were numerous osteoblasts in the boundary of the adjacent bone which was closely approximated to the $AlloDerm^{(R)}$ with regeneration features. However, the fibrous capsule also remained as in the group of $AlloDerm^{(R)}$ graft, which separated the $AlloDerm^{(R)}$ and the adjacent bone. Conclusions: These results suggest that $AlloDerm^{(R)}$ can be useful to substitute the autogenous dermis in the soft tissue defect. However, it may not be useful as a bone graft material or a carrier, since the bone defect was not completely healed by the bony tissue, regardless of the presence of osteogenic factors like rhBMP-2 or rhTGF-${\beta}1$.

Emulsion Graft Copolymerization of Methyl Methacrylate onto Cotton Fiber (면섬유에 대한 Methyl Methacrylate의 유화 그라프트 중합)

  • Bae Hyun-Sook;Ryu Hyo-Seon;Kim Sung-Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.15 no.3
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    • pp.271-280
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    • 1991
  • Emulsion graft copolymerization of MMA onto cotton fiber using Ce(IV) salt as an initiator was carried out. Graft yield and graft efficiency were observed according to the kinds and concentrations of emulsifier and polymerization conditions. The physical properties of MMA grafted cotton fabric were investigated. The results of this study were as follows: 1. The heighest graft yield of emulsion graft polymerization occurred at the concentration below cmc of emulsifier, which was different from emulsion polymerization. Nonionic sur- factant as an emulsifier was more effective than anionic one. 2. The highest graft yield was obtained at the initiator concentration $1{\times}10^{-2}mol/l$. The viscometric molecular weight of PMMA was in the order of 106. 3. As reaction time increased, the graft yield increased but the graft efficiency decreased. 4. Elevation of reaction temperature resulted in increase of graft yield. The apparent activation energy of MMA graft polymerization was 4.72 Kcal/mol. 5. Physical properties of MMA grafted cotton fabric varied with increase of grafting. Thickness and stiffness showed a noticeable increase, whereas tensile strength and elongation was slightly increased. Crease recovery increased as the graft yield increase up to $50\%$ and decreased thereafter.

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Study on the Preparation of Alginic Acid-PMMA Graft Polymer and the Surface Modification of Montmorillonite with the Graft Polymer (Alginic Acid-PMMA Graft Polymer의 합성 및 이를 Coupling제로 한 Montmorillonite 표면의 개질화에 관한 연구)

  • 손차호;김경환;박천욱
    • Textile Coloration and Finishing
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    • v.4 no.4
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    • pp.81-89
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    • 1992
  • Graft polymers of alginic acid-PMMA, different in composition and Mv of branched PMMA, were prepared by emulsion graft polymerization at various MMA concentrations. In aqueous dispersion solution, the adsorption of graft polymer on the montmorillonite was carried out to modify the surface property of powder, and the adsorption of PMMA in organic solvents (acetone, benzene) on the modified surface of powder were observed. The results obtained were as follows. 1. In emulsion graft polymerization of MMA on the sodium alginate in aqueous solution, SA conversion, MMA conversion and % grafting were increased with increasing MMA concentration where as graft efficiency was decreased. 2. The adsorption amount of graft polymer was increased with the elevation of temperature and the increased of dispersion concentration and with the increase of branched PMMA composition of graft polymer. 3. In organic solvent, the adsorption of PMMA on the surface modified particle was proceeded by the orientation along the stretched branched PMMA of adsorbed graft polymer which is in radial direction to the particle surface. 4. The adsorbed amount of PMMA was increased as the temperature and concentration of PMMA solution, the branching of adsorbed graft polymer and the solvency of solvent were increased.

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