• Proceedings of the KSLP Conference
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• 2003.11a
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• pp.183-183
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• 2003

Background and Objectives : Cartilage reconstruction is one of medical issue in otolaryngology. Tissue engineering is presently being utilized in part of cartilage repair. Sources of cells for tissue engineering are chondrocyte from mature cartilage and bone marrow mesenchymal stem cells that are able to differentiate into chondrocyte. Recent studies have shown that adipose tissue have mesenchymal stem cells which can differentiate into adipogenic, chondrogenic myogenic osteogenic cells and neural cell in vitro. In this study, we have examined chondrogenic potential of the canine adipose tissue-derived mesenchymal stem cell(ATSC). Materials and Methods : We harvested canine adipose tissue from inguinal area. ATSCs were enzymatically released from canine adipose tissue. Under appropriate culture conditions, ATSCs were induced to differentiate into the chondrocyte lineages using micromass culture technique. We used immunostain to type II collagen and toluidine blue stain to confirm chondrogenic differentiation of ATSCs. Results : We could isolate ATSCs from canine adipose tissue. ATSCs expressed CD29 and CD44 which are specific surface markers of mesenchymal stem cell. ATSCs differentiated into micromass that has positive response to immunostain of type II collagen and toluidine blue stain. Conclusion : In vitro, ATSCs differentiated into cells that have characteristic cartilage matrix molecules in the presence of lineage-specific induction factors. Adipose tissue may represent an alternative source to bone marrow-derived MSCs.

• Laser Solutions
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• v.14 no.2
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• pp.17-23
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• 2011

Active thin films are ubiquitous in the manufacture of all forms of flat panel display (FPD). One of the most widely employed thin films is indium tin oxide (ITO) and metal films used electrically conductive materials in display industries. ITO is widely used for fabrication of LCD, OLED device, and many kinds of optical applications because of transparency in visible range and its high conductivity and metal films are also widely employed as electrodes in various electric and display industries. It is important that removing specific area of layer, such as ITO or metal film on substrate, to fabricate and repair electrode in display industries. In this work, we demonstrate efficient selective ablation process to ITO and aluminum film on glass using a femtosecond laser (${\lambda}p=1025nm$) respectively. The femtosecond laser with wavelength of 1025nm, pulse duration of 400fs, and the repetition rate of 100kHz was used for selectively removing ITO and Al on glass in the air. We can successfully remove the ITO and Al films with various pulse energies using a femtosecond laser.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.17-24
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• 2012

This study evaluated the performance of Korean epoxy asphalt mixtures using several laboratory tests. Four types of epoxy asphalt mixtures were manufactured based on 13mm dense graded asphalt mixtures: three Korean and one Japanese epoxy asphalt mixtures where 20% or 40% of asphalt binder was replaced by epoxy resins. Curing time was determined as 3 and 6 hours for the mixtures containing 40% and 20% of epoxy resins, respectively. From the laboratory tests including wheel tracking, indirect tension fatigue, bending beam, and moisture susceptibility tests, it was concluded that the epoxy asphalt mixtures had superior performance than conventional asphalt mixtures except moisture susceptibility. Also, the performance of the Korean epoxy asphalt mixtures was comparable to the Japanese mixtures. Thermal coefficient, bond strength, and indirect tension tests were conducted to examine the applicability of the Korean epoxy asphalt mixtures to concrete repair. Its adhesion was strong enough to be bonded to surrounding concrete materials and its tensile strength was comparable to the concrete, but thermal expansion coefficient was 5 times greater than the surrounding concrete.

• Journal of Chest Surgery
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• v.16 no.4
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• pp.584-593
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• 1983

Esophageal reconstruction was performed in 344 patients with irreversible stricture of the esophagus resulting from caustic burns at National Medical Center from 1959 to 1982.There were 113 males and 231 females, and ranging from 2.5 to 58 years of age, and mean age was 26.5 years, and 25 cases were less than 10 years old. Caustic materials were 286 [83.2%] alkali and 50[14.5%] acid. The most frequent stricture site was upper thoracic esophagus as 56.7%, and the next was cervical as 31.4%, and lower, 11.9%. The stomach was involved in 10.8% totally, and hypopharyngeal stricture was also noticed in 3.2%, and in 3 cases, hypopharyngeal reconstruction was needed due to extensive scar change. In 329 of total 344 cases, colon interposition was performed without resection of the strictured esophagus except 4 cases which were complicated T-E fistula or perforation, and most of them, about 10-15 cm of terminal ileum with right half of the colon was used as the graft. The left colon with anti-peristalsis was used as graft only in 30 cases. The most common postoperative complication was anastomotic leak as 16.7% of total cases, and it was 12.5% from neck, 3.3% from ileocolostoma and 0.9% from cologastrostoma. Next common complication was neck stenosis [8.8%], aspiration pneumonia [6.4%], and graft necrosis [3.9%] in order. Overall operative mortality was 5.5% [14/329], and main causes of death were graft necrosis, sepsis due to anastomotic leak, gastric bleeding, and intestinal obstruction. Besides of colon interposition, according to shape or level of the stricture, plastic repair or segmental resection and direct anastomosis was done in 9, and 1 of them were complicated stenosis at the anastomotic site. In lower stricture, esophagogastrostomy was done in 10 cases, and 1 case expired due to hepatitis, and anastomotic stenosis was occurred in 2 cases at 1.5 months and 2.4 years later. During follow-up of 298 cases colon interposition from 6 months to 22 years, 82.6% was excellent, and 2.9% was complained of mild discomfort, and 4 cases were dead laterly, but 3 of them were not related to reconstruction.

• Journal of Chest Surgery
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• v.44 no.2
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• pp.178-182
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• 2011

Background: We analyzed the results of surgical reduction and fixation of ribs under thoracic epidural anesthesia and analgesia (TEA) in patients who had no more than 3 consecutive rib fractures with severe displacement to examine the clinical usefulness of this method. Materials and Methods: From May 2008 to March 2010, 35 patients underwent surgical reduction and fixation of ribs under TEA. We reviewed the indications for this technique, number of fixed ribs, combined surgical procedures for thoracic trauma, intraoperative cardiopulmonary events, postoperative complications, reestablishment of enteral nutrition, and ambulation. Results: The indications of TEA were malunion or nonunion of fractured ribs in 29 (82.9%; first operation) and incompletely ribs under previous general anesthesia in 6 (17.1%; second operation). The average number of fixed ribs per patient was 1.7 (range: 1~3). As a combined operation for thoracic trauma, 17 patients (48.6%) underwent removal of intrathoracic hematomas, and we performed repair of lung parenchyma (2), wedge resection of lung (1) for accompanying lung injury and pericardiostomy (1) for delayed hemopericardium. No patient had any intraoperative cardiopulmonary event nor did any need to switch to general anesthesia. We experienced 3 postoperative complications (8.6%): 2 extrapleural hematomas that spontaneously resolved without treatment and 1 wound infection treated with secondary closure of the wound. All patients reestablished oral feeding immediately after awakening and resumed walking ambulation the day after operation. Conclusion: Thoracic epidural anesthesia and analgesia (TEA) may positively affect cardiopulmonary function in the perioperative period. Moreover, this technique leads to an earlier return of gastrointestinal function and early ambulation without severe postoperative complications, resulting in a shortened hospital stay and lowered costs.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.163-170
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• 2005

Urban transit is a complex system that is combined electrically and mechanically, it is necessary to construct maintenance system for securing safety accompanying high-speed driving and maintaining promptly. Expert system is a computer program which uses numerical or non-numerical domain-specific knowledge to solve problems. In this research, we intend to develop the expert system which diagnose failure causes quickly and display measures. For the development of expert system, standardization of failure code classification system and creation of BOM(Bill Of Materials) have been first performed. Through the analysis of failure history and maintenance manuals, knowledge base has been constructed. Also, for retrieving the procedure of failure diagnosis and repair linking with the knowledge base, we have built RBR(Rule Based Reasoning) engine by pattern matching technique and CBR(Case Based Reasoning) engine by similarity search method. This system has been developed based on web to maximize the accessibility.

• Clinics in Shoulder and Elbow
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• v.8 no.2
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• pp.105-109
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• 2005

Purpose: To Analyze the exit site of pin inserted at the anterior glenoid rim in the reconstruction of the Bankart lesion and SLAP lesion using transglenoid suture technique. Materials and Methods: In the twenty adult right cadeveric scapula, insertions of pin were performed using guide at the position of 1, 2, 3 O'clock of glenoid rim. We measured the exit site of dorsal surface of the scapula by medial distance from sagittal plane of lateral border of scapular spine and the vertical distance from posterior border of the scapular spine. Results: When the pin was inserted caudally within 10 degree, at the position of 1, 2, 3 O'clock, the medial distance from lateral border of the scapula is averaged 29.4, 19.2, 34.0 mm respectively and the vertical distance from posterior border of the scapular spine is averaged 15.0, 18.6, 17.2 mm respectively. When the pin was inserted caudally within 20-30 degree, the medial distance is averaged 14.6, 14.2, 15.8 mm respectively and the vertical distance is averaged 31.6, 31.9, 32.1 mm respectively. Conclusion: When the pin was inserted caudally within ten degrees using the guide, the pin exit appeared at the more medial side of the base of scapular spine and the more inferior of scapular spine. This can make the firm suture tied over scapular spine during repair SLAP and the Bankart lesion, and also prevent the injury of suprascapular nerve.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.434-443
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• 2014

PURPOSE. The purpose of this study was to evaluate and compare the effects of different surface pretreatment techniques on the surface roughness and shear bond strength of a new self-adhering flowable composite resin for use with lithium disilicate-reinforced CAD/CAM ceramic material. MATERIALS AND METHODS. A total of one hundred thirty lithium disilicate CAD/CAM ceramic plates with dimensions of $6mm{\times}4mm$ and 3 mm thick were prepared. Specimens were then assigned into five groups (n=26) as follows: untreated control, coating with $30{\mu}m$ silica oxide particles ($Cojet^{TM}$ Sand), 9.6% hydrofluoric acid etching, Er:YAG laser irradiation, and grinding with a high-speed fine diamond bur. A self-adhering flowable composite resin (Vertise Flow) was applied onto the pre-treated ceramic plates using the Ultradent shear bond Teflon mold system. Surface roughness was measured by atomic force microscopy. Shear bond strength test were performed using a universal testing machine at a crosshead speed of 1 mm/min. Surface roughness data were analyzed by one-way ANOVA and the Tukey HSD tests. Shear bond strength test values were analyzed by Kruskal-Wallis and Mann-Whitney U tests at ${\alpha}=.05$. RESULTS. Hydrofluoric acid etching and grinding with high-speed fine diamond bur produced significantly higher surface roughness than the other pretreatment groups (P<.05). Hydrofluoric acid etching and silica coating yielded the highest shear bond strength values (P<.001). CONCLUSION. Self-adhering flowable composite resin used as repair composite resin exhibited very low bond strength irrespective of the surface pretreatments used.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.461-465
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• 2014

A 3-year-old colt Thoroughbred horse was referred with obvious lameness (3/5G) and mild heat and pain on left hoof of forelimb. He was diagnosed with quarter cracks that have a typical conformation of sheared heel, which are a different length and height between medial/lateral heels. Various materials and techniques were carried out to repair quarter cracks by using many different kinds of clips, bar shoes on fifth times for about 10 months. It worked on him without pain and heat on the cracked hoof, and then he could retrain for racing from the 36th weeks beginning of therapeutic shoeing. We suggested that especially fiberglass reinforced plastic (FRP) material and therapeutic shoeing were a great help to treat quarter cracks induced by sheared heel.

• Journal of Auto-vehicle Safety Association
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• v.8 no.3
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• pp.10-15
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• 2016

The purpose of this study is to evaluate the injury mechanism of facial injury related to an air-bag's deployment in occupant motor vehicle accident (MVA) by using Hospital Information System (HIS) and reconstruction program, based on the materials related to motor vehicle accidents. Among patients who visited the emergency department of Wonju Severance Christian Hospital due to motor vehicle accidents from August 2012 to February 2014, we collected data on patients with agreement for taking the damaged vehicle's photos. After obtaining the verbal consent from the patient, we asked about the cause of the accident, information on vehicle involved in the accident, and the location of car repair shop. The photos of the damaged vehicle were taken on the basis of front, rear, left side and right side. Damage to the vehicle was presented using the CDC code by analytical study of photo-images of the damaged vehicle, and a trauma score was used for medical examination of the severity of the patient's injury. Among the 309 patients with agreement for an investigation, thirty five (11.3 %) were the severe who had ISS over 15. And also, sixteen (5.2%) derived from the reconstructed data (maximum collision energy, maximum acceleration, delta V) by PC-Crash. As a result, ISS including the facial injuries was affected by the condition. It was high when the number of crash extent, the safety belt was not fastened, and the seating position of occupant and the direction of collision is same. For accurate analysis of the relationship between occupant injury and vehicle damage in MVAs, build-up of an in-depth database through carrying out various policies for motor vehicle accidents is necessary for sure.