• Archives of Craniofacial Surgery
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• v.22 no.5
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• pp.260-267
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• 2021

Background: Elastic ear cartilage is a good source of tissue for support or augmentation in plastic and reconstructive surgery. However, the amount of ear cartilage is limited and excessive use of cartilage can cause deformation of the auricular framework. This animal study investigated the potential of periosteal chondrogenesis in an ear cartilage defect model. Methods: Twelve New Zealand white rabbits were used in the present study. Four ear cartilage defects were created in both ears of each rabbit, between the central artery and marginal veins. The defects were covered with perichondrium (group 1), periosteum taken from the calvarium (group 2), or periosteum taken from the tibia (group 3). No coverage was performed in a control group (group 4). All animals were sacrificed 6 weeks later, and the ratio of neo-cartilage to defect size was measured. Results: Significant chondrogenesis occurred only in group 1 (cartilage regeneration ratio: mean±standard deviation, 0.97±0.60), whereas the cartilage regeneration ratio was substantially lower in group 2 (0.10±0.11), group 3 (0.08±0.09), and group 4 (0.08±0.14) (p= 0.004). Instead of chondrogenesis, osteogenesis was observed in the periosteal graft groups. No statistically significant differences were found in the amount of osteogenesis or chondrogenesis between groups 2 and 3. Group 4 showed fibrous tissue accumulation in the defect area. Conclusion: Periosteal grafts showed weak chondrogenic potential in an ear cartilage defect model of rabbits; instead, they exhibited osteogenesis, irrespective of their embryological origin.

• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.39-44
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• 2006

Purpose: The object of this study is to compare the Insall-Salvati ratio and Carton index between the patients who have an anterior cruciate ligament (ACL) tear and the patients who have no ACL tear. Materials and Methods: The study group included 114 patients who had an ACL tear and received arthroscopic reconstruction. The group I was acute ACL tear group, within 3 weeks after injury. The group II was chronic ACL tear group who had MRI was done after 3 weeks from injury. The group III was normal control group. We measured the Insall-Salvati ratio and Carton index on Magnetic Resonance Images (MRI) for all patients. Results: The Insall-Salvati ratio of control group was $1.02{\pm}0.12$ and Carton index of control group was $1.14{\pm}0.16$. The ACL-tear study group was $0.91{\pm}0.12\;and\;0.89{\pm}0.20$ respectively. The Insall-Salvati ratio and Caton index in ACL tear group was significantly less than those of control group. There were no significant differences in comparing with acute and chronic ACL tear group. Conclusion: Our study show that patella baja has an association with ACL tears, therefore in patients with an ACL tear who had patella baja, ideal graft for reconstruction was seriously considered.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.573-579
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• 2008

Background: Composite valve graft replacement is currently the treatment of choice for a wide variety of the lesions of aortic root disease. The purpose of this study was to explore the results of aortic root replacement after using the Cabrol technique over a 13-year period at our institution, and we analyzed the results to help surgeons make better decisions when repairing aortic root disease. Material and Method: Between January 1994 and December 2006, twenty-five patients underwent a Cabrol technique operation at our institution. The mean patient age was $43.7{\pm}14.1$ years old (range: $6{\sim}65$ years) and the male and female ratio was 21:4 (84% : 16%). The patients' follow-up was 100% complete, and the mean follow-up period was $60.7{\pm}50.4$ (range:$1{\sim}162$) months. Annuloaortic ectasia (n=18) was the most frequent cause of aortic disease in this series, followed by aortic dissection (n=7). The mean cardiopulmonary bypass time was $177.2{\pm}44.9$ minutes and the mean aortic cross clamping time was $123.4{\pm}34.1$ minutes. Nine patients were checked with MDCT (Multidetector computed tomography) for evaluating a well functioning secondary graft and the coronary anastomosis site. Result: The early mortality rate was 4% (1 of 25 patients). A significant stenosis, kinking or occlusion of the secondary graft was detected by MDCT in 4 patients. The overall survival rate was 88%. Conclusion: The Cabrol technique demonstrated a significant incidence of long-term complications such as secondary graft stenosis or obstruction. It could be used when the modified Bentall technique is not feasible.

• Journal of Integrative Natural Science
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• v.2 no.1
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• pp.1-12
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• 2009

This miniaccount presents the selective examples of our recent discoveries in the photopolymerization of vinyl monomers using the organic initiators such as hydrosilanes, poly(hydroarylsilane)s, benzoin silyl ethers, and thianthrene cation radical. In the photopolymerization of vinyl monomers with silanes polysilanes, while the polymerization yields and polymer molecular weights of the poly(MMA)s containing the silyl moieties decreased, the TGA residue yields and intensities of SiH stretching IR bands increased as the mole ratio of the silanes over MMA increased. The hydroarylsilane and poly(hydroarylsilane) seemed to influence strongly on the photopolymerizaiton of olefinic monomers as both chain initiation and chain transfer agents. For the photohomopolymerization and photocopolymerization of MA and AA, the similar trends were observed. Benzoin silyl ethers and thianthrene cation radical also exhibit the photoinitiating ability in the photopolymerization of MMA.

• Journal of Chest Surgery
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• v.20 no.2
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• pp.261-269
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• 1987

From 1976 through 1986, authors have experienced 127 cases of peripheral vascular surgery which had been done in this department. There were 29 cases of atherosclerosis obliterances including 7 Leriche syndrome, 32 Buerger`s diseases, 25 arterial thromboembolisms, 21 vascular injuries, 2 peripheral arterial aneurysms, 2 renovascular hypertensions, 1 congenital A-V malformation, 13 varicose vein of lower extremities, and 2 Jugular venous ectasia. Cases with vena caval disease and aortic disease were excluded. The mean age of ASO and Buerger`s disease was 56.1 yrs, 33.8 yrs respectively. The male to female ratio showed marked male preponderance [27:2, and 30:2], and almost every male patient was smoker. The indication of operation was similar in both disease entities. The method of operation for ASO were bypass procedure [17], thromboendarterectomy [6], and lumbar sympathectomy [5], and for Buerger`s disease were mainly sympathectomy and few bypass procedures and amputations. Seventeen patients with ASO were followed from 3 to 75 month and overall patency rate for bypass or endarterectomy in one and two months and 2 1/2 yr were 93%, 87%, and 31% respectively. Post operatively patient`s symptoms was relieved or alleviated in almost ASO patients, and about 60% of Buerger`s disease. We concluded that in patient with ischemic limb, we must revascularized aggressively for symptomatic relief. And choice of graft for bypass procedure was to be evaluated further.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.9
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• pp.791-797
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• 2014

Abstract Scaffold used as a carrier of the cell has been actively conducted using plenty of technology in tissue engineering. ${\beta}$-tricalcium phosphate (${\beta}$-TCP) material has shown good biocompatibility and osteoconductive ability when it was implanted as a bone graft substitute in osseous defect in human and animal studies for bone regeneration. In this study, we fabricated the blended polycaprolactone (PCL) and ${\beta}$-TCP scaffold by the polymer deposition system (PDS). The PCL/${\beta}$-TCP scaffold was fabricated at a temperature of $110^{\circ}C$, pressure of 650 kPa, and scan velocity of 100 mm/sec. The Overall geometry and size of the scaffold were fixed circle type with a diameter of 10 mm and a height of 4 mm. PCL/${\beta}$-TCP scaffold was observed by scanning electron microscopy. Cell attachment and proliferation of the scaffold containing 30 wt% ${\beta}$-TCP was superior to those containing 10 wt% and 20 wt% ${\beta}$-TCP.

• Elastomers and Composites
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• v.40 no.3
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• pp.159-165
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• 2005

Reactive monomer, glycidyl methacrylate (GMA), was grafted onto low density polyethylene (LDPE) using peroxide and then reactive blend with nylon-6 was rallied out by corotating twin screw extruder. Grafting of GMA was identified using FT-IR. Graft ratio or GMA increased with reaction temperature, peroxide concentration and styrene comonomer concentration. It is observed that tensile elongation and tensile strength or LDPE-g-GMA/nylon-6 blend were higher than those of LDPE/nylon-6 blend. Morphology of blend was analyzed using SEM.

• Journal of Periodontal and Implant Science
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• v.40 no.2
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• pp.96-101
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• 2010

Purpose: The purpose of this study was to evaluate the effect of collagen matrix with apically positioned flap (APF) on the width of keratinized gingiva, comparing to the results of APF only and APF combined with free gingival graft (FGG) at the second implant surgery. Methods: Nine patients were selected from those who had received treatments at the Department of Periodontics, Chosun University Dental Hospital, Gwangju, Korea. We performed APF, APF combined with FGG, and APF combined with collagen matrix coverage respectively. Clinical evaluation of keratinized gingival was performed by measuring the distance from the gingival crest to the mucogingival junction at the mid-buccal point, using a periodontal probe before and after the surgery. Results: The ratio of an increase was 0.3, 0.6, and 0.6 for the three subjects in the APF cases, 3, 5, and 7 for the three in the APF combined with FGG case, and 1.5, 0.5, and 3 for the three in the APF combined with collagen matrix coverage case. Conclusions: This study suggests that the collagen matrix when used as a soft tissue substitute with the aim of increasing the width of keratinized tissue or mucosa, was as effective and predictable as the FGG.

• Archives of Plastic Surgery
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• v.45 no.3
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• pp.253-258
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• 2018

Background The nasolabial flap is ideal for reconstruction of the nasal alar subunit due to its proximity, color and contour match, and well-placed donor scar. When raised as a random-pattern flap, there is a risk of vascular compromise to the tip with increased flap length and aggressive flap thinning. Surgical delay can greatly improve the chances of tip survival, allowing the harvest of longer flaps with greater reach. Methods We describe our technique of lengthening the nasolabial flap through multiple delay procedures. A bipedicled flap was first raised and then transferred as a unipedicled flap with a 6:1 length-to-width ratio. During the delay process, the flap tip was thinned to the subdermal layer. Results In our case series of seven patients, defects as far as the medial canthal area and contralateral ala were reconstructed successfully with no incidence of tip necrosis or flap loss. The resultant flaps were thin enough to be folded over for the reconstruction of alar rim defects. Conclusions We highlight the success of our surgical technique in creating thin and robust nasolabial flaps for the reconstruction of full-thickness defects around the nose.

• Journal of the Korean Applied Science and Technology
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• v.19 no.2
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• pp.131-136
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• 2002

As model waterborne acrylic coatings, mono-dispersed poly(butyl acrylate-methyl methacrylate) copolymer latexes of random copolymer and core/shell type graft copolymer were prepared by seeded multi-staged emulsion polymerization with particle size of $180{\sim}200$ nm using semi-batch type process. Sodium lauryl sulfate and potassium persulfate were used as an emulsifier and an initiator, respectively. The effect of particle texture including core/shell phase ratio, glass transition temperature and crosslinking density, and film forming temperature on the film formation and final properties of film was investigated using SEM, AFM, and UV in this study. The film formation behavior of model latex was traced simultaneously by the weight loss measurement and by the change of tensile properties and UV transmittance during the entire course of film formation. It was found that the increased glass transition temperature and higher crosslinking degree of latex resulted in the delay of the onset of coalescence of particles by interdiffusion during film forming process. This can be explained qualitatively in terms of diffusion rate of polymer chains. However, the change of weight loss during film formation was insensitive to discern each film forming stages-I, II and III.