• Journal of the Korean Society of Clothing and Textiles
• /
• v.13 no.1 s.29
• /
• pp.89-97
• /
• 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.

• Journal of Environmental Science International
• /
• v.12 no.2
• /
• pp.119-124
• /
• 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.

• Journal of the Korean Chemical Society
• /
• v.20 no.4
• /
• pp.251-259
• /
• 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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.26 no.3
• /
• pp.270-278
• /
• 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.

• Archives of Plastic Surgery
• /
• v.32 no.2
• /
• pp.267-270
• /
• 2005

The two major concerns in skin grafting are poor color match at the recipient site and donor site morbidity. To overcome the limitations of the classic skin graft, we have used dermis graft-deepithelialized split thickness skin graft-for coverage of small to medium sized wounds. The important aspects of this methods involve the immediate return of epidermis to the donor site to overcome donor site morbidity and restoration of the epidermis at the recipient site by neo epithelization from the adjacent skin. From April of 2001 to July of 2003, the dermis graft was applied to 32 patients. Simultaneously, the regular split thickness skin graft procedure was performed in 33 patients. We compared the healing time in all patients. The scar condition was also evaluated at 2 to 12 months after operation. The entire dermis grafts were reepithelialized in 15.5 days. The skin grafted wounds were healed by 11.8 days. Regarding the donor sites, donor sites of dermis graft healed within 7.5 days. On the contrary those of regular skin graft required 12.8 days. The donor sites of the dermis graft were also superior to those of skin graft in scar quality and patient satisfaction. The dermis graft technique for wound coverage compares favorably to regular skin graft technique in both recipient and donor sites aesthetically and functionally.

• Journal of Sericultural and Entomological Science
• /
• v.39 no.1
• /
• pp.62-66
• /
• 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..

• Journal of Sericultural and Entomological Science
• /
• v.20 no.2
• /
• pp.40-44
• /
• 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%.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.2
• /
• pp.220-229
• /
• 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-${\beta}1$.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.15 no.3 s.39
• /
• pp.271-280
• /
• 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.

• Archives of Plastic Surgery
• /
• v.41 no.1
• /
• pp.12-18
• /
• 2014

In patients having a short nose with a short septal length and/or severe columellar retraction, a septal extension graft is a good solution, as it allows the dome to move caudally and pushes down the columellar base. Fixing the medial crura of the alar cartilages to a septal extension graft leads to an uncomfortably rigid nasal tip and columella, and results in unnatural facial animation. Further, because of the relatively small and weak septal cartilage in the East Asian population, undercorrection of a short nose is not uncommon. To overcome these shortcomings, we have used the septal extension graft combined with a derotation graft. Among 113 patients who underwent the combined procedure, 82 patients had a short nose deformity alone; the remaining 31 patients had a short nose with columellar retraction. Thirty-two patients complained of nasal tip stiffness caused by a septal extension graft from previous operations. In addition to the septal extension graft, a derotation graft was used for bridging the gap between the alar cartilages and the septal extension graft for tip lengthening. Satisfactory results were obtained in 102 (90%) patients. Eleven (10%) patients required revision surgery. This combination method is a good surgical option for patients who have a short nose with small septal cartilages and do not have sufficient cartilage for tip lengthening by using a septal extension graft alone. It can also overcome the postoperative nasal tip rigidity of a septal extension graft.