• Archives of Craniofacial Surgery
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• v.21 no.5
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• pp.309-314
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• 2020

Reconstructions of extensive composite scalp and cranial defects are challenging due to high incidence of postoperative infection and reconstruction failure. In such cases, cranial reconstruction and vascularized soft tissue coverage are required. However, optimal reconstruction timing and material for cranioplasty are not yet determined. Herein, we present a large skull defect with a chronically infected wound that was not improved by repeated debridement and antibiotic treatment for 3 months. It was successfully treated with anterolateral thigh (ALT) free flap transfer for wound salvage and delayed cranioplasty with a patient-specific polyetheretherketone implant. To reduce infection risk, we performed the cranioplasty 1 year after the infection had resolved. In the meantime, depression of ALT flap at the skull defect site was observed, and the midline shift to the contralateral side was reported in a brain computed tomography (CT) scan, but no evidence of neurologic deterioration was found. After the surgery, sufficient cerebral expansion without noticeable dead-space was confirmed in a follow-up CT scan, and there was no complication over the 1-year follow-up period.

• The Korean Journal of Emergency Medical Services
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• v.8 no.1
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• pp.179-187
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• 2004

The purpose of the study was to injury types in Daegu subway fire accident, Sampung department store collapse, Mokpo airport civil aircraft accident, and Buan sunken ship disaster. The conclusion obtained from these analyses are as following. 1. The total of victims were Sampung department store collapse(l440 people). Buan sunken ship disaster(355 people), Daegu subway fire accident(340 people), and Mokpo airport civil aircraft accident(110 people). 2. The total of dead people were Sampung department store collapse(502 people), Buan sunken ship disaster(287 people), Daegu subway fire accident(192 people), and Mokpa airport civil aircraft accident(66 people). 3. The total of injured people were Sampung department store collapse(938 people), Daegu subway fire accident(148 people), Mokpo airport civil aircraft accident(84 people), and Buan sunken ship disaster(67 people). 4. The major types of victims presented smoke inhalation such as coughing, dyspnea, and sore throat in Daegu subway fire accident. 5. The major types of victims presented crushing(multiple fractures), vertebral, and soft tissues injuries in Sampung department store collapse. 6. The major types of victims presented multiple fractures. In addition to, a lot of people showed vertebral injuries and shock symptoms in Mokpo airport civil aircraft accident. 7. The major types of victims presented drowning as well lots of hypothermia patients in Buan sunken ship disaster. There were a wide variety of types in human disaster. Therefore, the most important disaster training program need to each disaster aspect in the local emergency medical services system. Moreover, the emergency medical services personnel should be understand and training for injury types of each human disaster.

• Korean Journal of Head & Neck Oncology
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• v.25 no.1
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• pp.39-42
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• 2009

Wide excision for curative treatment of malignant tumor on periauricular area often leads to loss of the external ear. But the auricle has rich vascular supply, Conservation of auricular contour is possible through salvage and engineering of remained auricular tissue. We experienced two cases of auricular salvage after wide excision of malignant tumor. In the first case, we performed two-staged technique. In first step, we covered soft tissue defect on periauricualr area with the anterolateral thigh free flap and remained auricle was floating over the flap after split-thickness skin graft was applied on it's posterior raw surface because it's survival was not confirmed. Second step was reposition of remained auricule on the anterolateral thigh flap. In the second case, we packed in periauricular dead space and external auditory canal with temoporalis muscle and temporoparietal fascial flap and then covered the flap with split thickness skin graft. In these two cases, there were no recurrence of tumors and we obtained cosmetically & functionally satisfactory results.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.485-495
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• 1998

Purpose : The major goal of the therapy in the soft tissue sarcoma is to control both local and distant tumor. However, the technique of obtaining local control has changed significantly over the past few decades from more aggressive surgery to combined therapy including conservative surgery and radiation and/or chemotherapy. We retrospectively analyzed the treatment results of the postoperative radiation therapy of soft tissue sarcoma and its prognostic factor. Materials and Methods : Between March 1983 and June 1994, 50 patients with soft tissue sarcoma were treated with surgery and postoperative radiation therapy at Kang-Nam St. Mary's hospital. Complete follow up was possible for all patients with median follow up duration 50 months (range 6-162 months). There were 28 male and 32 female patients. Their age ranged from 6 to 83 with a median of 44 years. Extremity (58$\%$) was the most frequent site of occurrence followed by trunk (20$\%$) and head and neck (12$\%$). Histologically malignant fibrous histiocytoma (23$\%$), liposarcoma (17$\%$), malignant schwannoma (12$\%$) constitute 52$\%$ of the patients. Daily radiation therapy designed to treat all areas at a risk for tumor spread upto dose of 4500-5000 cGy. A shrinking field technique was then used and total 55-65 Gy was delivered to tumor bed. Twenty-five patients (42$\%$) received chemotherapy with various regimen in the postoperative period. Results : Total 41 patients failed either with local recurrence or with distant metastasis. There were 29 patients (48$\%$) of local recurrence. Four patients (7$\%$) developed simultaneous local recurrence and distant metastasis and 8 patients (13$\%$) developed only distant metastasis. Local recurrence rate was rather higher than of other reported series. This study included patients of gross residual, recurrent cases after previous operation, trunk and head and neck Primary This feature is likely explanation for the decreased local control rate. Five of 29 Patients who failed only locally were salvaged by re-excision and/or re-irradiation and remained free of disease. Factors affecting local control include histologic type, grade, stage, extent of operation and surgical margin involvement, lymph node metastasis (p<0.05). All 21 patients who failed distantly are dead with progressive disease at the time of this report. Our overall survival results are similar to those of larger series. Actuarial 5 year overall survival and disease free survival were 60.4 $\%$, 30.6$\%$ respectively. Grade, stage (being close association with grade), residual disease (negative margin, microscopic, gross) were significant as a predictor of survival in our series (p<0.05). Conclusion : Combined surgery and postoperative radiation therapy obtained 5 year survival rate comparable to that of radical surgery.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.2
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• pp.241-252
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• 1992

The purpose of this study was to investigate the changes of morphology and structure of bone tissue in the irradiated mandibular bone in rats which were fed a low calcium diet. In order to carry out this experimant, 64 seven-week old Sprague-Dawley strain rats weighing about 150gms were selected and equally divided into one experimental group of 32 rats and one control group with the remainder. The experimental group and the control group were then subdivided into two groups when the rats reached ten-week old, 16 were assigned rats for each subdivided group, exposed to irradiation. The two irradiation groups received a single dose of 20 Gy in the jaws area only and irradiated with a cobalt-60 teletherapy unit. The rats in the control and experimental groups were serially terminated by fours on the 3rd, the 7th, the 14th, and the 21st day after irradiation. Following termination, both sides of the dead rats mandibular bodies were removed and fixed with 10% neutral formalin. One side of the mandibular body was radiographed with a soft X-ray apparatus. Thereafter, the obtained microradiographs were observed by a light microscope. The remaining side of the mandibular bone was further decalcified and embedded in paraffin as using the general method. The specimen sectioned and stained with hematoxylin and eosin, and Rabit Anti-Human Tumor Necrosis Factor-a, observed by a light microscope. The obtained results were as follows: 1. Microradiogram revealed that thinning of the cortex and a decrease in the trabecula of the interradicular bone and mandibular body were observed and noted from the start to finish throughout the experiment in the non-irradiated rats on the low calcium diet rather than in the non-irradiated rats on the normal diet. In microscopic observations, there were marked osteolytic changes in the center of the bone marrow. 2. Microradiogram revealed that thinning of the cortex and a decrease in the trabecula of interradicular bone and mandibular body were more marked after 7 days in the irradiated rats on the low calcium diet rather than in the non-irradiated rats on the low clacium diet. In microscopic observations, osteoblasts were decreased markedly after 7 days, and a few osteoclasts were observed. 3. Microradiogram revealed that thinning of the cortex and a decrease in trabecula of interradicular bone and the mandibular body were more marked from the strart to finish troughout the experiment in the irradiated rats on the low calcium diet rather than in the irradiated rats on the normal diet. In microscopic observations, there were no osteolytic changes noted in the irradiated rats on the normal diet. 4. In immunocytochemical findings, a few bone marrow cells including Tumor Necrosis Factor were observed in the irradiated rats on the normal diet, but was not observed in the rats on the low calcium diet.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.5
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• pp.10-24
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• 2007

In the dissertation, a power conversion system for fuel cell is composed of a PWM inverter with LC filter in order to convert fuel cell voltage to a single phase 220[V]. In addition, new insulated DC-DC converters are proposed in order that fuel cell voltage is boosted to 380[V]. In this paper, it requires smaller components than existing converters, which makes easy control. The proposed DC-DC converter controls output power by the adjustment of phase-shift width using switch $S_5\;and\;S_6$ in the secondary switch which provides 93-97[%] efficiency in the wide range of output voltage. Fuel cell simulator is implemented to show similar output characteristics to actual fuel cell. Appropriate dead time td enables soft switching to the range where the peak value of excitation current in a high frequency transformer is in accordance with current in the primary circuit. Moreover, appropriate setting to serial inductance La reduces communication loss arisen at light-load generator and serge voltage arisen at a secondary switch and serial diode. Finally, TMS320C31 board and EPLD using PWM switching technique to act a single phase full-bridge inverter which is planed to make alternating current suitable for household

• Journal of Sericultural and Entomological Science
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• v.50 no.1
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• pp.27-32
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• 2012

The aim of this study is to develop indoor-rearing methods of the diving beetles. In nature, both the adult diving beetle and its larvae are voracious aquatic predators. The larvae beetles hunt relatively bigger size of tadpoles and small fish for food source. However, due to difficulties of the food supplement for rearing diving beetles at indoor-condition further motivated us to develop new artificial food. Three separate experiments were performed. In the first experiment, adult beetles were provided with one of the several food choice treatments to self-compose their preferred foods that are affordable on the market at lower price. The second experiment was also to develop artificial diet that is possible for rearing larvae beetle under indoor condition. The larvae beetles were restricted to raw squid, artificial food source and mosquito larvae as a control at the first stadium and small fish and raw squid during second to third stadium duration. According to our result, adult beetles selected a food that made of boiled squid and dead small fish while, the young larvae consumed small fish, mosquito larvae and raw squid. Although, the larval food restriction on law squid caused noticeable decrease in survival, the result still supported the possible survival rate of keeping larvae at indoor condition. Moreover, pupation rate experiments, in which groups of larvae were placed at different mats, natural soil and fermented sawdust, showed that 80% of diving beetles pupated on the sawdust. This result indicates that female beetle preferentially selected to oviposit along soft and moist area.

• Archives of Plastic Surgery
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• v.38 no.2
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• pp.199-202
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• 2011

Purpose: Hyoid bone is a U-shaped bone in the anterior of the neck. Hyoid bone fractures are exceedingly rare and represent only 0.002% of all fractures because of its protective position relative to the mandible and its suspension by elastic musculature. We report a patient who presented hyoid bone fracture associated with hypoglossal nerve palsy. We also discuss the possible complication and treatment. Methods: A 69-year-old man was transferred from another institution because of persistent purulent discharge from the left chin. He had a history of trauma in which a knuckle crane grabbed his face and neck in the construction site. A CT scan at the time of the accident demonstrated a comminuted fracture of the right side of the mandible and hyoid bone fracture at the junction between body and right greater cornua. The displaced fracture of hyoid bone and fullness in the pre-epiglottic space were noted, probably indicating some edema. The patient was transferred into ICU after treatment of emergency tracheostomy because the patient showed respiratory distress rapidly. When the patient was hospitalized in our emergency room, he complained of dysphagia and pain when swallowing. On examination of oral cavity, the presence of muscle wasting with fasciculation of the tongue was noted and the tongue deviates to the left side on protruding from the mouth. Pharyngolarygoscopy was performed to make sure that there was no evidence of progressive swelling and pharyngeal laceration. Results: The patient underwent surgical removal of dead and infected tissue from the wound and reconstruction of mandibular bony defect by iliac bone grafting. Hyoid bone fracture was managed conservatively with oral analgesics, soft diet and restricted movement. Hypoglossal nerve palsy was resolved within 7 weeks after trauma without complications. Conclusion: Closed hyoid bone fracture is usually uncomplicated and thus it can be treated conservatively. Surgical intervention for hyoid bone fracture is recommended for patient with airway compromise, pharyngeal perforation and painful symptoms which show no response to conservative care. Furthermore, since respiratory distress syndrome may develop quickly, close observation is required. Besides, hypoglossal nerve palsy is a rarely recognized complication of hyoid bone fracture.

• Archives of Reconstructive Microsurgery
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• v.18 no.1
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• pp.23-26
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• 2009

Purpose: Artificial dura maters are commonly used in cranioplasty, but sometimes they can result in serious postoperative infection. Once complications such as epidural abscess or chronic draining ulcer arise, they are very difficult to treat. In this case, reclosure of dura defect using artificial dura mater may give rise to recurrence of infection. We experienced a case of intractable epidural abscess caused by use of artificial dura. To avoid repeated infection, we decided to use autologous tissue for the coverage of dura and soft tissue defect. Therefore, autologous tensor fascia lata graft and anterolateral thigh free flap were harvested at the same donor site incision to cover composite defect on the scalp and dura mater. Methods: A 13 year old male patient, who underwent the decompression cranioplasty and duroplasty, suffered from the intractable infection lesion. Twice, the epidural abscess was removed, both times the infection recurred. And eventually dura mater was exposed through the infected open wound. Nine months after dura exposed, infected aritificial dura mater was removed and extensive debridement was performed. Through a surgical incision on donor thigh, first, tensor fascia lata graft was harvested in process of the anterolateral thigh flap elevation. After the fascia lata graft was fixed over the dural defect, the anterolateral thigh flap was used to fill the dead space as well as the scalp defect. Results: Postoperatively, no recurrent infection and cerebrospinal fluid leakage are observed for a year. After the surgery, on the first and second day, venous congestion of the flap was observed, this problem was solved by thrombectomy and vein reanastomosis. And partial necrosis of flap occurred, but completely healed as conservative treatment for two weeks. Conclusion: Using the autologous tensor fascia lata graft and anterolateral thigh flap, we could obtain satisfactory results as treatment for the intractable infection lesion after duroplasty. Autologous tensor fascia lata in conjunction with anterolateral thigh flap is useful method for covering composite defect of scalp and dura mater.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.1-10
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• 2021

In this study, a circular pipe can be installed by suction pressure for construction on soft ground with a low-water level. A series of laboratory-scale model tests were conducted in sandy ground to comprehend the suction pressure of the circular pipe in low-water levels. For repeated tests on saturated sandy soil, a container was mounted with three vibration generators on the floor. A repetitive vibration was applied using the vibration system for ground compaction. In the model tests, different diameters and thicknesses on saturated sandy soil with a water depth were considered. The result showed that the suction pressure increased with increasing penetration depth of the circular pipe. Moreover, the suction pressure required to penetrate the pipe decreased with increasing diameter. In the low-water level, the total suction pressure measured at the top lid increased because additional suction pressure is required to lift the water column. On the other hand, this led to a decrease in suction pressure to penetrate the circular pipe because the weight of the water column is applied as a dead load. Therefore, it is necessary to consider the water level to design the required suction pressure accurately.