• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.27.1-27.9
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• 2016

Background: The objective of this study was to place bone graft materials in cranial defects in a rabbit model and compare their bone regenerating ability according to the size and density of demineralized dentin matrix (DDM). Methods: We selected nine healthy male rabbits that were raised under the same conditions and that weighed about 3 kg. Two circular defects 8 mm in diameter were created in each side of the cranium. The defects were grafted with DDM using four different particle sizes and densities: 0.1 mL of 0.25- to 1.0-mm particles (group 1); 0. 2 mL of 0.25- to 1.0-mm particles (group 2); 0.1 mL of 1.0- to 2.0-mm particles (group 3); and 0.2 mL of 1.0- to 2. 0-mm particles (group 4). After 2, 4, and 8 weeks, the rabbits were sacrificed, and bone samples were evaluated by means of histologic, histomorphometric, and quantitative RT-PCR analysis. Results: In group 1, osteoblast activity and bone formation were greater than in the other three groups on histological examination. In groups 2, 3, and 4, dense connective tissue was seen around original bone even after 8 weeks. Histomorphometric analysis of representative sections in group 1 showed a higher rate of new bone formation, but the difference from the other groups was not statistically significant. RT-PCR analysis indicated a correlation between bone formation and protein (osteonectin and osteopontin) expression. Conclusions: DDM with a space between particles of $200{\mu}m$ was effective in bone formation, suggesting that materials with a small particle size could reasonably be used for bone grafting.

• Archives of Plastic Surgery
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• v.32 no.1
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• pp.124-130
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• 2005

In the microsurgical era, replantation with microvascular anastomosis is considered as the most superior method in aspects of texture, color, shape in case of nose amputation. There are some reported cases of replantation in nose amputation historically, but most of them are composite graft cases rather than microvascular anastomosis. Only a few cases of successful nasal replantation with microvascular anastomosis have been reported due to the reason that the size of vessels is usually very small and identifying suitable vessels for anastomosis is difficult. Microanastomosis of artery and microanastomosis of vein are ideal in replantation, but identifying suitable veins is often difficult. Without venous anastomosis, resolving the venous congestion remains to be a problem. We can carry out arteriovenous shunt if we can find two arteries in amputee. However, the smaller the size of amputee is, the more difficult it is to find two arteries. Instead of arteriovenous shunt, we can try external venous drainage(frequently swab, pin-prick, stab incision, IV or local heparin injection, dropping, apply of heparin-soaked gauze, use of medical leech). Here, we present three cases of replantation with microscopical arterial anastomosis (one angular artery, two dorsal nasal arteries) and external venous drainage (stab incision, application of medical leech and heparin-soaked gauze) even though the size of amputee may be as small as $1.5{\times}1.0cm$. In all cases, surgical outcomes were excellent in cosmetic and functional aspects. This report describes successful replantation by microvasular anastomosis in case that suitable veins are not found.

• Journal of Chest Surgery
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• v.22 no.2
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• pp.256-264
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• 1989

Modified Blalock-Taussig operation remains the standard technique of systemic-to-pulmonary artery shunt in patients of congenital heart disease with decreased pulmonary blood flow. We reviewed the 41 patients who had been performed modified Blalock-Taussig operation from March 1985 to Feb. 1988, and angiographically measured pulmonary artery size before and after shunt, and calculated pulmonary artery index [PAI] and ratio of left and right pulmonary artery to descending aorta[[LPA+RPA]/dAo]. The mean duration of palliation after shunt operation was 624 days and mean age of the patient at shunt operation was 3.59 years. Mean PAI increased significantly from 131.15*67.11 mm2/M2 preoperatively to 232.70*84.46 mm2/M2 postoperatively. Mean ratio of right and left pulmonary artery to descending aorta also increased significantly from 1.48*0.40 preoperatively to 1.92*0.50 postoperatively. All patients manifested clinical improvement; there was mean decrease in hematocrit of 8.95%, mean increase in arterial oxygen saturation of 11.08%. Pulmonary arterial growth was not influenced by age at operation, initial pulmonary artery size, or graft size, but significantly influenced by antegrade flow. The patients who have some antegrade flow were in more increase of PAI. There were no linear correlation between change of PAI, change of [[LPA+RPA]/dAo], SaO2, and duration. But, according to Scatterplot between change of PAI and duration, some complex correlation was suggested and mean PAI was decreased after 2-year palliation. We concluded that modified Blalock-Taussig operation is excellent palliative surgery for pulmonary artery growth especially on the patient who have some antegrade flow, and the proper duration of palliation was about 2 years.

• Polymer(Korea)
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• v.26 no.1
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• pp.53-60
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• 2002

Polypropylene(PP : continuous phase)/poly (styrene-co-acrylonitrile)(SAN : dispersed phase) blends, and PP/poly(acrylonitrile-butadiene-styrene) (ABS : dispersed phase)blends, containing various amounts of compatibilizer(PP-SAN graft copolymer), were prepared at various shear rates by using twin-screw extruder. In the PP/SAN blend, the average size of the dispersed particles(SAN) was increased with SAN content, while the flexural strength and tensile strength were decreased with SAN content. When the screw rpm was increased from 10 to 60 rpm, the size of the dispersed phase was decreased while the flexural strength and the tensile strength were increased. Maximum mechanical strength and minimum droplet size were observed when the 5 phr compatibilizer was added to the PP/SAN blends. The mechanical strength of PP/ABS blends such as flexural strength and tensile strength increased by adding compatibilizer was reached maximum when blends contained 5 phr compatibilizer.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.2
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• pp.97-107
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• 2019

Objectives: Small animal maxillofacial models, such as non-segmental critical size defects (CSDs) in the rabbit mandible, need to be standardized for use as preclinical models of bone regeneration to mimic clinical conditions such as maxillofacial trauma. The objective of this study is the establishment of a mechanically competent CSD model in the rabbit mandible to allow standardized evaluation of bone regeneration therapies. Materials and Methods: Three sizes of bony defect were generated in the mandibular body of rabbit hemi-mandibles: $12mm{\times}5mm$, $12mm{\times}8mm$, and $15mm{\times}10mm$. The hemi-mandibles were tested to failure in 3-point flexure. The $12mm{\times}5mm$ defect was then chosen for the defect size created in the mandibles of 26 rabbits with or without cautery of the defect margins and bone regeneration was assessed after 6 and 12 weeks. Regenerated bone density and volume were evaluated using radiography, micro-computed tomography, and histology. Results: Flexural strength of the $12mm{\times}5mm$ defect was similar to its contralateral; whereas the $12mm{\times}8mm$ and $15mm{\times}10mm$ groups carried significantly less load than their respective contralaterals (P<0.05). This demonstrated that the $12mm{\times}5mm$ defect did not significantly compromise mandibular mechanical integrity. Significantly less (P<0.05) bone was regenerated at 6 weeks in cauterized defect margins compared to controls without cautery. After 12 weeks, the bone volume of the group with cautery increased to that of the control without cautery after 6 weeks. Conclusion: An empty defect size of $12mm{\times}5mm$ in the rabbit mandibular model maintains sufficient mechanical stability to not require additional stabilization. However, this defect size allows for bone regeneration across the defect. Cautery of the defect only delays regeneration by 6 weeks suggesting that the performance of bone graft materials in mandibular defects of this size should be considered with caution.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.610-618
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• 2008

Background: There are various treatment modalities for atherosclerotic arterial obstructive disease at the lower limbs, for example, conservative physical therapy, medication, operation etc. Yet it has been established that an arterial bypass operation is the most effective treatment. The aim of this study is to evaluate the effect of arterial bypass operation within our experience and to determine the indicators of treatment. Material and Method: Ninety six patients received arterial bypass operation for atherosclerotic arterial obstructive disease from June 2002 to April 2006. We evaluated the feasibility of arterial bypass operation based on the improvement of symptoms and the ankle-brachial index (ABI) and the surgical outcomes, as based on the complications, the amputation rates and the patency rates. We also assessed the possible risk factors such as gender, age, a smoking history, co-morbidities, the anastomotic sites, the graft size and the graft type. We retrospectively reviewed the medical records of the patients. The total mean follow-up period was $29.4{\pm}13.1$ months. Result: The mean age was $65.95{\pm}9.61$ and there were 88 male patients. The most common clinical manifestation was ischemic resting pain in the lower extremities. The underlying combined diseases were hypertension (61%), diabetes (43%), cardiac problems (35%) and smoking (91.7%). The most frequent site of arterial obstruction was the superficial femoral artery (44 cases, 40%). A femoropopliteal artery bypass operation with a Polytetrafluoroethylene(PTFE) synthetic graft was done in 44 cases (40%) and the great saphenous vein graft was used in 11 cases. The postoperative ABI increased significantly from $0.30{\pm}0.11$ preoperatively to $0.63{\pm}0.11$ (p<0.001) postoperatively. In 8 cases, amputations above the ankle level were necessary. The graft patency rates were 86.4% and 68.0% after 1 and 3 years, respectively. There were 29 cases (30.21%) of patency failure; the male gender, smokers and hypertension were significantly more frequent in the failure group. Of these, hypertension was the most powerful risk factor (p=0.042). Conclusion: The arterial bypass operation is an effective treatment modality for controlling the symptoms such as pain and claudication, and for preventing major amputations for the patients with atherosclerotic arterial obstructive disease. This study suggests quitting smoking, strict blood pressure control, selection of an appropriate graft, regular outpatient follow up and proper medication would offer higher patency rates and more favorable outcomes.

• Journal of Korean Academy of Nursing
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• v.17 no.3
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• pp.227-240
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• 1987

Infection has assumed increased importance as a cause of death among thermally injured individuals. Decreased treatment effectiveness and an increase in mortality are the hallmarks of nosocomial infection. Infection control is a monumental task that must be achieved to reduce mortalities. This was a retrospective study to survey the epidemiological features of nosocomial infections in a burn unit and to identify the possibilities for infection control. During the past 6 year 2 month period from July, 1981 to August, 1987, 306 burn patients were treated in the burn unit of university hospital. Among of these, 290 cases were the subjects of this study. The data were collected from the patients' records after discharge. All data collected were analyzed using percent, x$^2$-test, t-test with SPSS program. The results of this study are summariged as follows: 1) Infection rate was 40%. According to site, there were 67 cases of wound infection, 60 cases of post-operative skin graft infection, 20 cases of septicemia and 20 cases of donor site infection. As far as the burn size was concerned, the infection rate for patients whose burn size ranged 61 to 70%, was shown to be 100%, followed by the infection rate of 93.8%, for patients whose burn size ranged from 41~50%. As far as the period of time over which the infection developed, 5 to 7 days showed the highest frequency. Further infection was the main cause of deaths and complications. 2) Based upon the results obained by comparing the general characteristics, between a hospital infection-group and non-hospital infection group, there was a significant defference according to age, the time of the year when the accident happened, the place of accident or length of hospital-admission. And according to the result obtained by comparing the general characteristics of the burn, there was a significant difference according to burn size, burn depth, burn type, and burn site. And also based upon the result obtained by comparing the two groups according to method of treatment, there was a significant difference according to the use of antibiotics and to the type of wound-treatment, and for the 8 different binds of treatment related to infection, there was a significant difference for all. In conclusion, age, length of hospital-admission, burn size, burn type, burn site, burn depth, type of woundtreatment and the 8 different binds of treatment, which are related to burns, were shown to be the factors which affect the infection rate in burn patients.

• Korean Journal of Head & Neck Oncology
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• v.22 no.1
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• pp.36-39
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• 2006

The Neurofibroma is a benign neoplasm originating from neural tissue such as Schwann cell, fibroblast and peripheral fibroblast, which rarely converts to malignancy. About 25-45% of neurofibroma are located in head and neck, and the most common sites are lateral cervical region and mouth. Because of its high vascularity and invasion to the adjacent organs, surgical resection may be confronted and limited, moreover large neurofibroma can cause large defect that needs various kinds of flap. The factors related to clinically suspected malignancy are painlessness, abrupt increase in size, firm fixation, and central ulceration, although the malignancy rate of neurofibroma is low. The complete resection was failed several times at local clinic, the patient was transferred to our hospital. We have successfully removed the retroauricular neurofibroma using transposition flap & free skin graft on its large defects.

• Journal of environmental and Sanitary engineering
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• v.20 no.2 s.56
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• pp.47-55
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• 2005

The World Health Organization(WHO, 1998) and the United States Environmental Protection Agency (USEPA, 1992) recommended $2{\mu}\;guranium/{\ell}$ in drinking water as a guideline. The Korea Institute for Environmental Research recently reported that the radioactive pollution in ground water was almost negligible In Korea$(1999\~2002)$. Cs were cast into beads(2mm in wet form) and treated with hexamethylene diisocyanate for stability in acidic aqueous solution through cross-linking of the beads surfaces. The removal study was carried out in a static batch system and a flow system. In the static system, a certain amount of sample water was confined in a vessel and beads(dry weight 0.5g) were packed into it in order to adsorb uranium for a certain period of time. Afterwards the remaining uranium in water vessel was determined by inductively coupled plasma mass spectrometry. The effective pH range was 4 to 8. The smaller the size of beads, the better the removal efficiency. Furthemore, the lower the flow rates, the higher the removal efficiency. The results showed that chitosan beads can be effectively used for the removal of uranium contained in water.

• Journal of Korea Society of Digital Industry and Information Management
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• v.16 no.2
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• pp.95-104
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• 2020

Bribery is one of the world's most destructive and challenging issues. Yet despite efforts on national and international levels to tackle bribery, it remains a significant issue. Recognizing this, ISO has developed a new standard to help organizations fight bribery and promote an ethical business culture, which is "ISO 37001 - Anti-bribery Management Systems" in 2016. ISO 37001 can provide the tools and systems to greatly reduce the risk and help organizations deal with it effectively if it does arise. It is a flexible tool, which can be adapted according to the size and nature of the organization and the bribery risk it faces. After enforcing the Improper Solicitation and Graft Act, Korean government standardized ISO 37001, one of the Business Ethics of Global Standard, harmonizing International Standards into Korean Industrial Standards (KS) in 2017. It is meaningful in that Korean companies have localized regulation which applies to global standard anti-bribery management systems. Only about 100 organizations, however, have adopted ISO 37001 so far. The primary purpose of this paper is to examine the expectation and awareness of ISO 37001. Results show that still many organizations lack of awareness of ISO 37001 and it is implicated that much promotion and education will be necessary. This study has originality and value in that it can provide the guidelines for activation of ISO 37001.