• Archives of Plastic Surgery
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• v.38 no.3
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• pp.235-240
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• 2011

Purpose: Management of pressure sores has been improved, along with development of musculocutaneous flaps and perforator flaps. Nowadays, the treatment of pressure sore with perforator flaps has shown several advantages, including minimal donor site morbidity, relatively versatile flap design not only in primary cases but also in recurred cases and minimized anatomical rearrangement of regional muscle position. In this study, we report our clinical experience of gluteal perforator flap used in the treatment of a greater trochanteric pressure sore. Methods: A clinical study was performed on 7 patients who underwent total 10 operations. 1 superior gluteal artery perforator flap and 9 inferior gluteal artery perforator flaps were used to reconstruct the defect, followed by the mean observation duration of 22 months. Results: There were no total flap loss. We treated 2 cases of partial flap loss with debridement and primary repair. 2 recurred cases were successfully treated using the same method. Donor sites were all primarily repaired. Conclusion: The gluteal perforator flap could be considered as a safe and favorable alternative in the treatment of soft tissue defects in the greater trochanteric area. The advantages of the flap include low donor site morbidity and the possibility of versatile flap design not only in primary cases but also in recurred cases.

• Journal of Power System Engineering
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• v.13 no.5
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• pp.95-102
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• 2009

A steam generator (boiler) in thermal power plants, consisting of more than 30,000 parts and components, can lead to the plant shutdown with damage to even the small part of the components; esp., like weld failures on boiler tubes. Consequently it is greatly demanded to improve the quality of the weld on the boiler tube for the stable operation of the power plants. Because of the feature of the welding, which is done past by melting the work pieces and adding a filler material that cools to become a strong coalescence, there is a great possibility that weld failures take place. As a result, it is regulated to make a non-destructive testing, like radiography test, to detect defects and flaws in the weld. The current film radiography test provides a lower image quality exceeding 2.0% of a basic quality level for a penetrameter, it is very likely to fail to detect micro defect. As a result, the prevention for the boiler tube failure has not been made effectively. In this study, computed radiography technology has been applied as a digital radiography test to the boiler tube weld, and Se-75 radiation source was used to improve the image quality, instead of Ir-192 source. As a result of this study, it is proven to save the time and cost for test and to enhance the quality level of penetrameter penetrating image, which enables to upgrade the quality of radiography test to the boiler tube weld.

• Journal of Trauma and Injury
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• v.26 no.3
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• pp.151-156
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• 2013

Purpose: Traumatic cervical SCI is frequently accompanied by dural tear and the resulting cerebrospinal fluid (CSF) leak after surgery can be troublesome and delay rehabilitation with increasing morbidity. This study evaluated the incidence of intraoperative CSF leaks in patients with traumatic cervical spinal cord injury (SCI) who underwent anterior cervical surgery and described the reliable management of CSF leaks during the perioperative period. Methods: A retrospective study of medical records and radiological images was done on patients with CSF leaks after cervical spine trauma. Results: Seven patients(13.2%) were identified with CSF leaks during the intraoperative period. All patients were severely injured and showed structural abnormalities on the initial magnetic resonance image (MRI) of the cervical spine. Intraoperatively, no primary repair of dural tear was attempted because of a wide, rough defect size. Therefore, fibrin glue was applied to the operated site in all cases. Although a wound drainage was inserted, it was stopped within the first 24 hours after the operation. No lumbar drainage was performed. Postoperatively, the patients should kept their heads in an elevated position and early ambulation and rehabilitation were encouraged. None of the patients developed complications related to CSF leaks during admission. Conclusion: The incidence of CSF leaks after surgery for cervical spinal trauma is relatively higher than that of cervical spinal stenosis. Therefore, one should expect the possibility of a dural tear and have a simple and effective management protocol for CSF leaks in trauma cases established.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.12 no.2
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• pp.246-250
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• 2009

Congenital diaphragmatic hernias (CDH) usually cause respiratory distress soon after birth and are associated with a high mortality rate in the early postnatal period. However, there is a milder form of CDH that does not manifest during the neonatal period. The late presenting CDH is characterized by a variable clinical picture. We present the case of an otherwise healthy 5-month-old girl, who was referred for evaluation of an 1-day history of vomiting and irritability. Chest simple X-ray and CT showed bowel loops in the left thoracic cavity, which was consistent with diaphragmatic hernia. At operation, she was found to have a small left posterolateral diaphagmatic defect with viable small bowel loops in the left thoracic cavity. After surgical reposition of the hernia, the symptoms such as vomiting and irritability subsided. The lack of typical manifestation of CDH such as respiratory distress may lead to delayed diagnosis. The possibility of late presenting CDH should not be overlooked even after the neonatal period.

• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.47-54
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• 1995

This study was to measure the properties of logs and classify them by non-destructive methods. The purpose of this experiment was focused at mensurability of logs by non-destructive methods. The non-destructive instrument, Stress-Wave Timer 239A which was made by Metriguard in U.S.A., was used. The stress wave velocities of log's cross direction were measured and compared with three different methods; 1. with hammer, 2. with hammer and D.B.H. meter, 3. with manufactured instrument. Number of used logs were seven logs, which were classified by naked eye into six groups; very severe rot, severe rot, mild rot & knot, mild rot & check, mild rot, sound log, and in diameter were into three groups; large(57.4cm), medium(36~41.2cm), small(28.9cm) log. The results, which were classified by mensurability with non-destructive methods, were followed; 1. The stress wave velocities were very different between rot and sound log. So it meant the possibility of mensurability of logs by non-destructive method even if high standard error. 2. The stress wave velocities decreased with checks more than with rots, which meant the checks affected speeds more. 3. The stress wave velocities increased with knot. 4. The velocities with manufactured instrument showed lower standard error, so more accurate results than other methods. Especially the required labour decreased from 3~4 to 2 persons. 5. Finally, the mensurability showed more accurate results and made the classification of logs scientific.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.247-250
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• 2005

The need for improved fuel efficiency, weight reduction has motivated the automotive industry to focus on aluminum alloys as a replacement for steel-based alloy. To cope with the needs for high structural rigidity with low weight, it is forecasted that substantial amount of cast components will be replaced by tubular parts which are mainly manufactured by the extruded aluminum tubes. The extrusion process is utilized to produce tubes and hollow sections. Because there is no weld seam, the circumferential mechanical properties may be uniform and advantageous for hydroforming. However the possibility of the occurrence of a surface defect is very high, especially due to the temperature increase from forming at high pressure when it comes out of the bearing and the roughness of the bearing, which cause the surface defects such as the dies line and pick-up. And when forming a extruded aluminum tube, the free surface of the tube becomes rough with increasing plastic strain. This is well known as orange peel phenomena and has a great effect not only on the surface quality of a product but also on the forming limit. In an attempt to increase the forming limit of the tubular specimen, in the present paper, surface asperities generated during the hydroforming process are polished to eliminate the weak positions of the tube which lead to a localized necking. It is shown that the forming limit of the tube can be considerably improved by simple method of polishing the surface roughness during hydroforming. And also the extent of the crack propagation caused by dies lines generated during the extrusion process is evaluated according to the deformed shape of the tube.

• Plant Biotechnology Reports
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• v.3 no.2
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• pp.157-165
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• 2009

Human erythropoietin (EPO) is a leading product in the biopharmaceutical market, but functional EPO has only been produced in mammalian cells, which limits its application and drives up the production costs. Using plants to produce human proteins may be an alternative way to reduce the cost. However, a recent report demonstrated that overexpression of the human EPO gene (EPO) in tobacco or Arabidopsis rendered males sterile and retarded vegetative growth, which raises concern whether EPO might interfere with hormone levels in transgenic plants. In the present study, we demonstrated that overexpressing EPO with additional 5'-His tag and 3' ER-retention peptides in tobacco did not cause any developmental defect compared to GUS plants. With our method, all 20 transgenic plants grew on selective medium and, further confirmed by PCR, were fertile. Most of them grew similarly compared to GUS plants. Only one transgenic plant (EPO2) was shorter in plant height but had twice the life span compared to other transgenic plants. When 11 randomly selected EPO plants, along with the abnormal plant EPO2, were subjected to RT-PCR analysis, all of them had detectable EPO transcripts. However, their protein levels varied considerably; seven of them had detectable EPO proteins analyzed by western blot. Our results indicate that overexpressing human EPO protein in plants does not have detrimental effects on growth and development. Our transformation systems allow us to further explore the possibility of glycoengineering tobacco plants for producing functional EPO and its derivatives.

• Archives of Reconstructive Microsurgery
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• v.22 no.1
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• pp.33-37
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• 2013

Purpose: The concept and development of perforator free flaps have led to significant advances in microsurgery. Ongoing developments in perforator free flap surgery are aimed at reducing complications and improving surgical outcomes. The aim of this study was to evaluate the effectiveness and application of supermicrosurgery in free flap surgery. Materials and Methods: A total of 267 patients with soft tissue defects of the lower extremity due to various etiologies from January, 2007 to January, 2013. The patients received either an anterolateral thigh free flap (n=83), a superficial circumflex iliac artery free flap (n=152), an upper medial thigh free flap (n=19), or a superior gluteal artery perforator free flap (n=13). Microanastomosis was performed using a perforator-to-perforator technique, either end-to-end or end-to-side. Results: The mean postoperative follow up period was eight months (range: one to 16 months) and flap loss occurred in 11 cases out of 267. All cases of flap loss occurred within two weeks of surgery due to either arterial insufficiency (n=5) or venous congestion (n=6). Conclusion: Supermicrosurgery enables the selection of the most efficient perforator for microanastomosis at the defect site. It also reduces the time required for dissection of recipient vessels, and reduces the possibility of injury to major vessels. Microsurgery using a vessel of less than 1 mm has been reported to increase the risk of flap failure; however, using the most advanced surgical tools and developing experience in the technique can produce success rates similar to those found in the literature.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.224-228
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• 2005

The effect of primary tooth infection on permanent teeth was reported by many previous study. It is seen histologic change in the enamel forming organ and in the surrounding sac, thus produce the defect as either hypoplasia or hypocalcification and alter the eruption of the permanent teeth. The periapical inflammation cause permanent tooth displacement in various direction and can be classified into the three categories : rotation, deflection inversion. This study reported case which displacement of succedaneous teeth may be caused by periapical infection of primary dentition and concluded that treatment procedure of infected primary tooth is selected and performed by importance to retain the tooth for space maintain, possibility to successfully restored, evidence of abnormal development of the succedaneous tooth.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.12-16
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• 2011

During the shipbuilding construction, the repair works will be occurred by various reasons such as the natural disaster, mistakes of engineers or workers, defect of material, and so on. The one of the engineer's responsibilities is to design considering every possibility and to prevent the repair works due to the mistakes during construction stages, but actually it is very difficult and impossible to avoid every mistake. However, it is also the responsibility of engineers to find the best solution for the unavoidable mistakes which is to maintain the capacity of vessel and guarantee the safety for the repair works considering the construction schedules and economic cost. In this paper, it will be introduced the brief of repair works to the structural damage of the moon-pool structure in drillship which is built in our shipyard. For the verification of the structural strength, the fatigue analysis has been carried out based on the guide of Classification society. Furthermore, the modifications of structure design and welding procedure have been applied to avoid the stress concentration in the moon-pool structure.