• Title/Summary/Keyword: grafting degree

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

  • Kim, Goo-Ni;Chun, Yong-Chul;Oh, Sang-Taek;Park, Seung-Hyeun;Lee, Chang-Ho;Yoo, Chong-Sun;Min, Byung-Kwon
    • Elastomers and Composites
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    • v.29 no.5
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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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Photoinitiator-free Photo-reactive Coloration of Wool Fabrics Using C.I. Reactive Black 5

  • Dong, Yuanyuan;Jang, Jin-Ho
    • Textile Coloration and Finishing
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    • v.24 no.2
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    • pp.97-105
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    • 2012
  • Compared with conventional adsorption-based coloration, the photoreactions of dyes such as photo-copolymerization and photo-crosslinking under UV irradiation can be employed for the coloration of textiles, which can be carried out without salt addition at room temperature. C.I. Reactive Black 5, a homo-bifunctional reactive dye containing two sulfatoethylsulfone groups, is used as a photo-reactive dye for wool fibers. Upon UV irradiation, the photo-reactive dye was grafted onto wool fabrics without photoinitiators. Since the disulfide bonds in the cystine residues of wool can be easily photodecomposed to active thiyl radicals which initiate the polymerization, the dye can be polymerized to an oligomeric dye of a degree of polymerization of 12 or more. The grafted fabrics reached a grafting yield of 2.3% o.w.f. and a color yield (K/S) of 18.2 by the photografting of an aqueous dye concentration of 9% using a UV energy of 25J/$cm^2$. Furthermore, the photochemically dyed wool fabric showed higher colorfastness properties to light, laundering and rubbing comparable to conventional reactive dyeing.

Chondroblastoma of the Talus Mimicking an Aneurysmal Bone Cyst: A Case Report (동맥류성 골낭종으로 오인된 거골에 발생한 연골모세포종: 증례 보고)

  • Park, Ji Soo;Suh, Jin Soo;Choi, Jun Young
    • Journal of Korean Foot and Ankle Society
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    • v.23 no.1
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    • pp.31-34
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    • 2019
  • Chondroblastoma is a rare benign tumor that produces giant cells and cartilage matrix. The tumor occurs in people between 10 and 25 years with slightly higher incidence in males. The condition occurs in the proximal epiphysis of the tibia and humerus, distal epiphysis of the femur, but its occurrence in the talus is relatively rare, accounting for 4% of the total number of chondroblastoma cases. Chondroblastoma is often misdiagnosed as a primary aneurysmal bone cyst, giant cell tumor, chondromyxoid, and lesion of a secondary aneurysmal bone cyst by fibrous dysplasia. The most commonly used surgical method for chondroblastoma is broad curettage with bone grafting. In general, an aneurysmal bone cyst is associated with a second degree chondroblastoma, which is approximately 20%. Chondroblastoma of the talus and secondary aneurysmal bone cysts can be misdiagnosed as primary aneurysmal bone cysts. This paper reports a case of a young male patient with chondroblastoma of the talus, which was initially misdiagnosed as an aneurysmal bone cyst with involvement of the talo-navicular joint.

Surgical Treatment for Left Main Coronary Atresia with Significant Mitral Regurgitation in a 1-Year-Old Child

  • Ryu, Seung Woo;Pyo, Won Kyung;Choi, Eun Seok;Park, Chun Soo;Yu, Jeong Jin;Yun, Tae-Jin;Chung, Cheol Hyun
    • Journal of Chest Surgery
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    • v.54 no.1
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    • pp.72-74
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    • 2021
  • Congenital atresia of the left main coronary artery (LMCA) is an extremely rare coronary anomaly that necessitates surgical correction. Patients with LMCA atresia may have various clinical symptoms, which are determined by the degree of collateral vessel development from the right coronary system, the metabolic demands of the heart, and concomitant mitral insufficiency caused by myocardial ischemia. Unlike in adults, there are limited surgical options for coronary artery disease in children. Herein, we report a case of LMCA atresia with mitral regurgitation in a 19-month-old child that was successfully corrected by coronary artery bypass grafting and mitral valve repair.

Effects of Protein Functionality on Myofibril Protein-Saccharide Graft Reaction

  • Kim, Tae-Kyung;Yong, Hae In;Cha, Ji Yoon;Kim, Yun Jeong;Jung, Samooel;Choi, Yun-Sang
    • Food Science of Animal Resources
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    • v.42 no.5
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    • pp.849-860
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    • 2022
  • The myofibril protein (MP) isolate-saccharide graft reactions was prepared using the Maillard reaction with saccharides. The effects of various saccharides on protein functionality and quality of the Maillard reaction were investigated and compared with those of MP. The grafting degree of the MP isolate-saccharide graft reaction was significantly higher in the reducing sugar-treated groups (lactose, glucose, fructose, and palatinose). The browning intensity of the MP isolate-saccharide graft reaction with fructose, sucrose, and erythitol was higher than that observed in the control reaction (p<0.05). MP that reacted with reducing sugars (glucose, fructose, palatinose, and lactose) had fainter bands than MP that reacted with non-reducing sugars (sucrose, erythitol, trehalose, sorbitol, and xylitol). MPs conjugated with glucose exhibited higher protein solubility. The palatinose and lactose treatments were maximum in water binding capacity, though no significant difference in oil binding capacity among the saccharide treatments was observed. The emulsion stability of the MP isolate-saccharide graft reaction with palatinose and erythitol was higher than that of the control reaction. Therefore, reducing sugars have good protein functionality in the MP isolate-saccharides graft reaction.

A step-by-step intraoperative strategy during one-stage reconstruction of an acute electrical burn injury in the neck for superior surgical outcome in India: a case report

  • Mainak Mallik;Sanjay Kumar Giri;M. Vishnu Swaroop Reddy;Kallol Kumar Das Poddar
    • Journal of Trauma and Injury
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    • v.37 no.2
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    • pp.151-157
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    • 2024
  • Electrical burn injuries can cause more damage than clinical evaluations initially suggest. The energy waves penetrate from the surface to the deepest layers of tissue, causing extensive harm at every level. The neck is a critical area, both functionally and aesthetically. We present a case involving a young male patient with a severe fourth-degree electrical burn on the neck, who underwent a single-stage debridement and reconstructive surgery. The pectoralis major myocutaneous flap is a versatile option for various head and neck reconstructions. However, if the donor site cannot be closed primarily and requires split-thickness skin grafting, it can result in unsightly scars and deformities. For large flap paddles, it is ideal to reconstruct the secondary defect with locoregional flaps. In this case, we successfully reconstructed the donor site's secondary defect using a contralateral internal mammary artery perforator flap, without resorting to any skin grafts. The early postoperative results demonstrated satisfactory cosmesis, patient satisfaction, and functional outcomes.

Proposed Treatment Protocol for Frostbite: A Retrospective Analysis of 17 Cases Based on a 3-Year Single-Institution Experience

  • Woo, Eun-Kyung;Lee, Jong Wook;Hur, Gi-Yeun;Koh, Jang-Hyu;Seo, Dong-Kook;Choi, Jai-Ku;Jang, Young-Chul
    • Archives of Plastic Surgery
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    • v.40 no.5
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    • pp.510-516
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    • 2013
  • Background This paper discusses the treatment protocol for patients with frostbite. Methods We performed a retrospective analysis of a series of 17 patients with second- and higher-degree frostbite who had been treated at our medical institution between 2010 and 2012. Results Our clinical series of patients (n=17) included 13 men and four women, whose mean age was $42.4{\pm}11.6$ years (range, 22-67 years). The sites of injury include the foot in six patients (35.3%), the hand in six patients (35.3%) and the facial region in five patients (29.4%). Seven patients with second-degree frostbite were completely cured with only conservative treatment during a mean period of $12.7{\pm}3.3$ days (range, 8-16 days). Of the five patients with third-degree frostbite, two underwent skin grafting following debridement, and the remaining three achieved a complete cure with conservative treatment during a mean period of $35{\pm}4.3$ days (range, 29-39 days). Five patients with fourth-degree frostbite were treated with surgical procedures including amputation. Conclusions With the appropriate conservative management in the early stage of onset, surgeons should decide on surgery after waiting for a sufficient period of time until the demarcation of the wound. Continuous management of patients is also needed to achieve functional recovery after a complete cure has been achieved. This should also be accompanied by patient education for the avoidance of re-exposure to cold environments.

The Recovery of Left Ventricular Function after Coronary Artery Bypass Grafting in Patients with Severe Ischemic Left Ventricular Dysfunction: Off-pump Versus On-pump (심한 허혈성 좌심실 기능부전 환자에서 관상동맥우회술시 체외순환 여부에 따른 좌심실 기능 회복력 비교)

  • Kim Jae Hyun;Kim Gun Gyk;Baek Man Jong;Oh Sam Sae;Kim Chong Whan;Na Chan-Young
    • Journal of Chest Surgery
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    • v.38 no.2 s.247
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    • pp.116-122
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    • 2005
  • Background: Adverse effects of cardiopulmonary bypass can be avoided by 'Off-pump' coronary artery bypass (OPCAB) surgery. Recent studies have reported that OPCAB had the most beneficial impact on patients at highest risk by reducing bypass-related complications. The purpose of this study is to compare the outcome of OPCAB and conventional coronary artery bypass grafting (CCAB) in patients with poor left ventricular (LV) function. Material and Method: From March 1997 to February 2004, seventy five patients with left ventricular ejection fraction (LVEF) of $35\%$ or less underwent isolated coronary artery bypass grafting at our institute. Of these patients, 33 patients underwent OPCAB and 42 underwent CCAB. Preoperative risk factors, operative and postoperative outcomes, including LV functional change, were compared and analysed. Result: Patients undergoing CCAB were more likely to have unstable angina, three vessel disease and acute myocardial infarction among the preoperative factors. OPCAB group had significantly lower mean operation time, less numbers of total distal anastomoses per patient and less numbers of distal anastomoses per patient in the circumflex territory than the CCAB group. There was no difference between the groups in regard to in-hospital mortality $(OPCAB\; 9.1\%\;(n=3)\;Vs.\;CCAB\;9.5\%\;(n=4)),$ intubation time, the length of stay in intensive care unit and in hospital postoperatively. Postoperative complication occurred more in CCAB group but did not show statistical difference. On follow-up echocardiography, OPCAB group showed $9.1\%$ improvement in mean LVEF, 4.3 mm decrease in mean left ventricular end-diastolic dimension (LVEDD) and 4.2 mm decrease in mean left ventricular end-systolic dimension (LVESD). CCAB group showed $11.0\%$ improvement in mean LVEF, 5.1 mm decrease in mean LVEDD and 5.5 mm decrease in mean LVESD. But there was no statistically significant difference between the two groups. Conclusion: This study showed that LV function improves postoperatively in patients with severe ischemic LV dysfunction, but failed to show any difference in the degree of improvement between OPCAB and CCAB. In terms of operative mortality rate and LV functional recovery, the results of OPCAB were as good as those of CCAB in patients with poor LV function. But, OPCAB procedure was advantageous in shortening of operative time and in decrease of complications. We recommend OPCAB as the first surgical option for patients with severe LV dysfunction.

Surface Modification of Matrix and filler for Ultra High Density Elastomeric Material (초 고비중 탄성체 개발을 위한 매트릭스 탄성체 표면개질 및 충전제 제어기술 기초연구)

  • Chung, K.;Lee, D.;Yang, K.;Lee, W.;Hong, C.
    • Elastomers and Composites
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    • v.40 no.2
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    • pp.93-103
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    • 2005
  • In this study, surface treatment of the elastomeric matrix was investigated to develop a substituting material for steel dynamic damper of automobile. The key technology is to get ultra high density elastomeric compound in order to substitute steel dynamic damper. The optimum matrix material(chloroprene rubber) and filler(metal powder) were selected for this. The several properties of elastomeric compound were examined. According to the results, the $t_{s2}$ of filled elastomeric compound was decreased with increasing the filler loading whereas the $t_{90}$ was increased. Also, tensile strength and rebound resilience were decreased with filler loading. To solve the problem of high filler loading, the photo grafting technique was employed on elastomeric matrix. The degree of grafting was determined by FTIR-ATR. Also, the filler surface was modified by chemical etching and the surface morphology was examine by SEM. After chemical treatment of filler, the particle size analyzer was used to examined the particle size, size distribution, and morphology of the modified filler.

CLINICAL STUDY ON THE IMMEDIATE IMPLANTATION WITH GTR THERAPY, INCLUDING BONE HEALING OF EXTRACTION SOCKETS (유도조직재생술에 의한 발치창의 골치유 및 즉시 임프란트 매식에 대한 임상적 연구)

  • Park, Kwang-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.18 no.2
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    • pp.224-235
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    • 1996
  • Early implantation before sufficient ossification has taken place usually results in osseointegartion failure due to reduced bone-fixture interface area. However, various studies have shown successful osseointegration results following immediate implants concurrently with GTR. The clinical trends have been to shorten the patients' edentulous state by immediate implantation, and reduce the alveolar bone resorption. However, it may be difficult to attain the complete soft tissue coverage of the sites, increasing the chance of infection. Furthermore, there may be more studies needed on the clinical behaviors of e-PTFE membranes, various modofications in the membrane materials and bone graft materials. Various animal and clinical studies have been reported on the successful osseointagration following immediate implantation, but the long-term follow-up studies are limited. The present study investigated 16 immediately-implanted implants with GTR therapy with or without calcium carbonate grafting on 11 patients 3 years after installation and 24-30 months after functional loading. Based on the clinical, radiographic and histologic findings, the following results have been attained. 1. Clinically, stability has been shown on all 16 implants throughout the investigated periods. 2. Radiologically, the alveolar bone loss has progressed up to the polished neck portion but not beyond it, suggesting the progressive osseointegration from the GTR therapy. 3. The GTR method used in the present study is easy to use clinically, and may be appied in the regeneration of ossoeous defects around implants and in the immediate implantation. 4. The difficulty in complete tissue coverage may be avoided by delaying the installation for 2 to 3 weeks after the extraction allowing certain degree of soft tissue healing.

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