• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.2
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• pp.73-79
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• 2012

We developed the carbon fabric/EPDM chamber insulation in order to protect motor case with high intensity gas flow. A six-inch simulation motor connected with extension tube was designed to test ablation characteristic of insulation. High intensity gas flow was induced by a FRP disc with hole between motor and extension tube. After ground test, ablation depth of the carbon fabric/EPDM insulation was decreased compared to another insulations after ground static test.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.85-91
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• 2011

We developed carbon fabric/EPDM chamber insulation in order to protect motor case with high intensity gas flow. Six-inch simulation motor connected with extension tube was designed to test ablation characteristic of insulation. High intensity gas flow was induced by FRP disc with hole between motor and extension tube. After ground test, ablation depth of carbon fabric/EPDM insulation was decreased compared to another insulations after ground static test.

• Tuberculosis and Respiratory Diseases
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• v.58 no.1
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• pp.64-67
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• 2005

We report here on an uncommon case of mediastinitis that occurred after central venous catheterization. A patient with colon and jejunal cancer complained high fever, right shoulder pain, chest pain, and limited motion of the affected shoulder just 6 days after central venous catheterization. Bacterial culture of the blood, shoulder abscess, and catheter puncture site revealed methicillin-resistent staphylococcus aureus. Right upper mediastinal widening on chest film also suggested mediatinitis. Mediastiotomy and pus drainage was performed along with adequate antibiotics therapy. In this case, it seems that initially formed bacteria from the puncture site migrated to the mediastinum through the tissue plane to start the mediastinitis. Careful dressing of puncture site and correct handling of catheter is important to prevent this serious complication.

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.315-323
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• 2001

Changes in somatosensory evoked potentials (SEPs) which accompanied by insertion of foreign body in spinal canal were evaluated with clinical signs and positive contrasted myelography in dogs. Foreign bodies occupied 20∼50% of spinal canal. Foreign bodies occupying about 50% of spinal canal were inserted into the animals of group II and III for 1 week and 2 days, respectively. Foreign bodies occupying about 20% of spinal canal were inserted into the animals of group IV, V, and for 1 week, 2 days, and 8 weeks, respectively. in group I (control group), sham operation (lateral laminectomy) was performed. Group III, IV and V did not severely affect on SEPs latencies and clinical signs. Group VI affects on SEPs latencies but not on clinical signs. After foreign body removal, SEPs latencies showed similar recovery patterns with clinical signs. However, group II induced severe abnormalities in SEPs latencies and clinical signs. In group III, IV and V, thoracic potentials (TN1) were abnormally recorded after foreign body insertion and firstly/normally recorded on the 6th 9.5th and 3.5th day after foreign body (removal following) insertion. In group VI, TN1 was abnormally recorded after foreign body insertion and firstly recorded on the 7.7th day and normally recorded on 34th day after foreign body insertion. In group I, TN1 was not recorded from the 3rd day after foreign body insertion and until the 8th week after foreign body removal. In group I, TN1 was firstly recorded on the 1st day after laminectomy.

• Childhood Kidney Diseases
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• v.11 no.1
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• pp.51-58
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• 2007

Purpose : To assess the early complication of laparoscopic peritoneal dialysis catheter implantation in children. Methods : Medical record review was carried out on 21 laparoscopic and 16 conventional peritoneal dialysis catheter implantations which were performed in 31 children under 18 years of age between 2002 and 2006. All medical records were retrospectively analyzed. The patients were followed until 2 months after catheter placement. Patient characteristics and catheterrelated complications, such as significant bleeding, leakage, obstruction, migration, insertion site infection and peritonitis during the first 60 days after implantation were recorded. Results : After conventional operation, dialysate leakage occurred in 2 of 16 cases and all cases improved after conservative management. In 1 case, significant bleeding occurred and re-operation was performed. Three cases of obstruction due to migration were reported, 2 cases underwent reoperation and 1 case improved without intervention. After laparoscopic surgery, outflow obstruction occurred in 1 out of 21 cases, which was caused by adhesion after several reinsertions of the catheter and recurrent peritonitis. No migration was noted after laparoscopic surgery. There was no significant difference in the complication rate between the two groups. Conclusion : Laparoscopic peritoneal dialysis catheter placement is feasible in children of all age groups, with at least equivalent functional results compared to conventional surgery. The additional advantage of laparoscopic catheter insertion is the option to identify and eliminate anatomical risk factors, such as intra-abdominal adhesions, and to perform partial omentectomy without additional incisions.

• Korean Journal of Head & Neck Oncology
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• v.28 no.1
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• pp.8-11
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• 2012

배경 및 목적 : 섬유소 응고제(fibrin sealants)는 다양한 두경부수술에서 지혈목적으로 사용되고 있다. 본 연구의 목적은 배액관을 삽입하지 않는 갑상선 수술에서 섬유소 응고제의 효용성과 안정성을 알아보고자 하였다. 재료 및 방법 : 최근 1년간 108명의 갑상선 수술환자 중에서 수술 후 배액관의 삽입없이 수술을 받은 103명의 환자를 대상으로 하여 임상적인 특징을 분석하였다. 결과 : 103명의 대상환자 중에서 남성은 16예, 여성은 87예였다. 대상환자의 평균연령은 $46.7{\pm}13.0$세였고, 연령분포는 17세에서 72세였다. 갑상선 종물의 평균크기는 $2.08{\pm}1.61cm$였고, 종물의 크기는 최소 0.2cm에서 최대 10.0cm까지의 분포를 보였다. 수술에는 갑상선 엽절제술이 5예, 갑상선반절제술이 41예, 아갑상선 절제술이 8예, 갑상선 전절제술이 6예, 갑상선 전절제술과 중심경부림프절 절제술이 37예, 갑상선 전절제술과 선택적경부림프절 절제술이 6예가 있었다. 수술 후 합병증은 11예(10.6%)에서 발생하였고, 발생한 합병증으로는 장액성종창이 3예, 혈종이 1예, 일측성 성대마비가 3예, 저칼슘혈증이 4예 있었다. 성대마비는 수술 후 3개월 이내에 모두 호전되었고, 장액성 종창은 반복적인 세침흡인으로 호전되었다. 1예의 혈종은 지연성으로 발생하였고, 수술 후 5일째에 수술을 통해 제거하였다. 결론 : 이러한 결과에 근거하여 갑상선 수술에서 섬유소 응고제의 사용은 다양한 갑상선 수술에서 효과적인 지혈과 함께 안전하게 사용될 수 있으며, 배액관의 삽입을 감소시켜 줄 수 있을 것으로 생각된다.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.85-87
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• 2004

We fabricated flexible thermoradiotherapy probes to alternated combination with Interstitial hyperthermia and Brachyradiotherapy thermoradiotherapy probe was coated by gold plate on polyethylene brachytherapy probe. When Agar phantom was heated 15 minute with 30 W radiofrequency power, temperature increased as 5oC for polyethylene probe and 20oC for gold coated polyethylene probe. We observed that the 1 cm square array would heat a volume with a 1.25 cm radius circular field cross section to therapeutic temperatures (90% relative SAR using Tm) and the 2 cm square array with a 1.75 cm radius rectangular field with central inhomogeneity. With 2 cm long electrode implants, we observed that the 1 cm square array would heat a 3 cm long sagittal section to therapeutic temperature (90% relative SAR using Tm). The histopathological changes associated with RF heating of normal canine brains have been correlated with thermal distributions. RF needle electrode heating was applied for 50 min to generate tissue temperatures of 43${\circ}$C. We obtained a quarter of the heated tissue material immediately after heating and sacrificed at intervals from 7${\sim}$30 days. The acute stage was demonstrated by liquefactive necrosis, pyknosis of neuronal element in the gray matter. Mild gliosis occurring around the necrosis was demonstrated in the last sacrificed (days30)canine brain.

• Korean Journal of Optics and Photonics
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• v.26 no.1
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• pp.1-8
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• 2015

The most common cause of a heart attack is known as coronary artery disease, which narrows the arteries and reduces the blood flow to the heart. To treat coronary artery stenosis, percutaneous coronary intervention (PCI) (a nonsurgical procedure to install a stent, which holds the artery wall open) is performed. Intracoronary optical coherence tomography (OCT) is a catheter-based, invasive optical imaging system. To determine whether PCI is appropriate, and to perform stent evaluation in a catheterization laboratory, OCT examinations are carried out. This review details the fundamental principles and technological status of intracoronary OCT imaging, and discusses the ongoing clinical applications to determine the benefits of OCT-guided PCI.

• Journal of Energy Engineering
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• v.15 no.1 s.45
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• pp.60-66
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• 2006

An experimental investigation on the flow and convective heat transfer characteristics has been carried out far aluminum foam heat sink inserted into the annulus to examine the feasibility as a heat sink. Two aluminum foams or different permeability were selected to provide the friction factor and heat transfer correlations as function of Darcy, Reynolds and Prandtl number. Experimental results show that the friction factor is higher than clear annulus without aluminum foam, while $6\sim10$ times augmentation in Nusselt number is obtained. This technique can be used for the compactness of the heat exchanger.

• Tuberculosis and Respiratory Diseases
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• v.59 no.4
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• pp.389-396
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• 2005

Background : Central venous catheters(CVCs) area major source of nosocomial infection. Chlorhexidine-silver sulfadiazine coated catheters (CHSS) were developed to reduce the rate of CVC infection. However, the clinical effectiveness of CHSS in comparison wth non-coated catheter (NCC) remains to be evaluated. Methods : From January 2004 to December 2004 in medical intensive care unit (ICU) of Asan Medical Center, CVCs were inserted in 446 cases. We retrospectively analyzed characteristics of patients and catheterization,the catheter-related infection rate and colonization, microbiologic findings, and insertion sites (subclavian, jugular, femoral) according to the type of inserted CVCs (NCC: 187 cases, CHSS: 259 cases). Catheter related infection is defined as catheter related bacteremia and catheter related non-bacteremic sepsis. Results : 1) The mean age of the patients in each group was $62{\pm}16$ years, $63{\pm}15$ years (p=0.42), and sex ratio 94:50, 141:69 (p=0.9) in NCC and CHSS. Duration of ICU admission ($29{\pm}37$, $26{\pm}44$ p=0.42), duration of mechanical ventilation ($17{\pm}22$, $15{\pm}19$ p=0.17), and APACHE III score at the time of CVC insertion ($81{\pm}34$, $82{\pm}37$ p=0.61) were not different between both groups. 2) Mean duration of catheterization was 118 in NCC and 119 in CHSS (p=0.98). Number of catheter-days was 2176 days in NCC and 3035 days in CHSS. Catheter-related infection occurred in 9 (4.8%) cases receiving NCC and 4 cases (1.5%) receiving CHSS. Catheterrelated infection incidence per 1000 catheter-days was 4.1 and 1.3, respectively (p=0.04). CHSS was associated with a significant reduction of infection in jugular catheters regarding to insertion sites (p=0.01). 3) Microorganisms causing infection were Staphylococcus aureus (n=3), Candida (n=3), coagulase-negative Staphylococci (n=2), and Klebsiella (n=1) in NCC, and Candida species (n=2), coagulase-negative Staphylococci (n=2), Proteus (n=1) in CHSS. Conclusion : CHSS has significantly reduced the episodes of infection compared to NCC in jugular catheterization in medical ICU.