• Journal of Chest Surgery
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• 제26권1호
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• pp.32-35
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• 1993

During the period from September 1989 through December 1992, 118 cases of coronary arterial bypass graft were performed at Department of Cardiothoracic Surgery, Asan Medical Center. Twenty-one of these had history of recent or remote percutaneous transluminal coronary angioplasty. They consisted of 13 males[age,58.7 + 5.4 years] and 8 females[age, 63.6 + 2.8years] with the mean age of 60.6. History of old myocardial infarction was noted in 24%[5/21] of the patients and congestive heart failure in 2 cases. The angina by type of presentation is unstable in all of the patients. The patterns of involvement of coronary arterial disease were left main disease[1], single vessel disease[5], double vessel involvement[10], and triple vessel involvement[5]. We performed 4 cases of single bypasses, 7 cases of double, 8 cases of triple, and 2 cases of quadruple bypasses. Total of 51 grafts[LIMA:12, RSVG:39] were inserted in 21 cases with average of 2.4 grafts per patient. The methods of myocardial protection were cold blood cardioplegia[8 cases], intermittent aortic occlusion[11], and continuous coronary perfusion with local coronary sharing[2]. There were no operative or late death. The only cardiac complication was 1 case of low cardiac output required IABP. The other complications were 1 case of sternal wound infection and 1 case of postoperative bleeding required reoperation. And there was no case of perioperative myocardial infarction. Postoperatively, 3 cases of recurrent angina were detected at 5, 7, and 18months after surgery. One of them was managed successfully with repeat PTCA[who was recurred 18 months postoperatively], and the other two with medication. I conclude that we can approach the patients more aggressively with PTCA, because of our acceptable operative risks.

• Journal of Chest Surgery
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• 제15권4호
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• pp.432-439
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• 1982

Congenital posterolateral diaphragmatic hernia [Bochdalek hernia] is the result of a congenital diaphragmatic defect in the posterior costal part of the diaphragm in the region of the tenth and eleventh ribs. There is usually free communication between the thoracic and abdominal cavities. The defect is most commonly found on the left [90%], but may occurs on the right, where the liver often prevents detection. The male to female ratio is 2:1. Owing to the negative intrathoracic pressure, herniation of abdominal contents through the defects occurs, with resultant collapse of the lung. Shifting of mediastinum to the opposite side and compression of the opposite lung occurs. Most often these hernias are manifestated by acute respiratory distress in the newborn. A second, but less well recognized, group of patient with Bochdalek hernia survive beyond the neonatal period, usually present at a later time with "failure of thrive, intermittent vomiting, or progressive respiratory difficulty. " The diagnosis can often be made on clinical ground from the presence of respiratory distress, absence of breath sounds on the chest presence of bowel sounds over the chest . Roentgenogram of the chest confirm the diagnosis. Obstruction and strangulation have been reported but are rare. Treatment consists of early reliable identification of these congenital diaphragmatic hernia with high risk and surgical repairment. and postoperative pharmacological management with extracorporeal membranous oxygenation [=ECMO] support in the period of intensive care. On the surgical approach, for defects on left side, an abdominal incision is preferred, because of the high incidence of malrotation and obstructing duodenal bands. In the neonate, the operative mortality may be appreciable, but, later repair almost always is successful. During the period from 1972 to 1982, 4 cases of congenital Bochdalek hernia were experienced at the Kyung-Hee University Hospital.

• Tuberculosis and Respiratory Diseases
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• 제63권1호
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• pp.88-93
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• 2007

저자 등은 단일 폐종괴로 발견되어 결핵이나 종양과의 감별이 쉽지 않아 개흉 조직검사를 통해 Wegener 육아종증을 진단 후 면역 억제 치료를 하였으나 폐렴 및 호흡부전이 발생한 증례를 경험하였기에 보고하는 바이다.

• Journal of Chest Surgery
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• 제18권4호
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• pp.692-699
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• 1985

Fifty cases of Open Heart Surgery due to congenital and acquired heart disease were done using the cardiopulmonary bypass in the Department of Thoracic and Cardiovascular surgery, Chosun University Hospital from November, 1980 to June, 1985. 1. The age of the congenital heart disease was from 7 to 29 years, the mean age was 14.5 years. In the acquired heart disease, the age was from 14 to 48 years, and the mean age was 22.3 years. The ratio of male to female was about 1.8:1. 2. The number of congenital cyanotic heart disease were 7 patients, congenital acyanotic heart disease were 17 patients and acquired valvular heart disease were 26 patients. All of the acquired heart disease was one or more valve disease. 3. Preoperative symptoms of the congenital heart disease were exertional dyspnea [cyanotic 100%, acyanotic 70.6%] and palpitation [cyanotic 28.6%, acyanotic 76.1%], and the acquired heart diseases were exertional dyspnea [92.3%], palpitation [34.1 %], and chest discomfort [30.8%]. 4. The method of the myocardial protection during the cardiopulmonary bypass were mild or moderate hypothermia, intermittent coronary perfusion of the cardioplegic solution, topical myocardial hypothermia with 4oC Hartmann`s solution. 5. In the cases of the valve replacement, postoperative oral anticoagulant therapy was started at oral intake of food using the warfarin and persantin, and the prothrombin time was maintained 30-50% of control value during 3-6 months for tissue valve replacement and permanently for metal valve replacement. 6. The postoperative complications were appeared in 24 cases and the complications were wound infection, occipital alopecia, hemorrhage etc. 7. The mortality after open heart surgery was 8 percents and the cause of death was low cardiac output syndrome, right heart failure, DIC, and Left ventricle rupture.

• Journal of Korean Neurosurgical Society
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• 제62권5호
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• pp.567-576
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• 2019

Objective : Minimal data exist regarding non-operative management of suspected pseudarthrosis after pedicle subtraction osteotomy (PSO). This study reports radiographic and clinical outcomes of non-operative management for post-PSO pseudarthrosis at a minimum 5 years post-detection. Methods : Nineteen consecutive patients with implant breakage indicating probable pseudarthrosis after PSO surgery (13 women/six men; mean age at surgery, 58 years) without severe pain and disability were treated with non-operative management (mean follow-up, 5.8 years; range, 5-10 years). Non-operative management included medication, intermittent brace wearing and avoidance of excessive back strain. Radiographic and clinical outcomes analysis was performed. Results : Sagittal vertical axis (SVA), proximal junctional angle, thoracic kyphosis achieved by a PSO were maintained after detection of pseudarthrosis through ultimate follow-up. Lumbar lordosis and PSO angle decreased at final follow-up. There was no significant change in Oswestry Disability Index (ODI) scores and Scoliosis Research Society (SRS) total score, or subscales of pain, self-image, function, satisfaction and mental health between detection of pseudarthrosis and ultimate follow-up. SVA greater than 11 cm showed poorer ODI and SRS total score, as well as the pain, self-image, and function subscales (p<0.05). Conclusion : Non-operative management of implant failure of probable pseudarthrosis after PSO offers acceptable outcomes even at 5 years after detection of implant breakage, provided SVA is maintained. As SVA increased, outcome scores decreased in this patient population.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권12호
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• pp.4682-4705
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• 2020

The Unmanned Aerial Vehicles (UAV) networks consisting of low-cost UAVs are very vulnerable to smart jammers that can choose their jamming policies based on the ongoing communication policies accordingly. In this article, we propose a novel cloud and edge-aided mobile communication scheme for low-cost UAV network against smart jamming. The challenge of this problem is to design a communication scheme that not only meets the requirements of defending against smart jamming attack, but also can be deployed on low-cost UAV platforms. In addition, related studies neglect the problem of decision-making algorithm failure caused by intermittent ground-to-air communication. In this scheme, we use the policy network deployed on the cloud and edge servers to generate an emergency policy tables, and regularly update the generated policy table to the UAVs to solve the decision-making problem when communications are interrupted. In the operation of this communication scheme, UAVs need to offload massive computing tasks to the cloud or the edge servers. In order to prevent these computing tasks from being offloaded to a single computing resource, we deployed a lightweight game algorithm to ensure that the three types of computing resources, namely local, edge and cloud, can maximize their effectiveness. The simulation results show that our communication scheme has only a small decrease in the SINR of UAVs network in the case of momentary communication interruption, and the SINR performance of our algorithm is higher than that of the original Q-learning algorithm.

• 항공우주시스템공학회지
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• 제17권6호
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• pp.144-148
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• 2023

항공기 배터리는 항공기의 엔진 시동 전원 및 비상 전원을 공급하는 역할을 하는 핵심 장비이다. 배터리는 안정적인 전원 공급을 위해 언제나 충분한 용량을 보장하도록 충전되어야 하며 높은 신뢰성을 유지해야 한다. T-50 계열 항공기 배터리는 -18 ℃ 이상의 낮은 온도에서 엔진을 최대 2회 시동할 수 있도록 설계하였으나, 겨울철에 엔진 시동에 실패하는 현상이 간헐적으로 발생하였다. 이에 본 논문에서는 배터리의 저온 충전 시 발생하는 실패 현상에 대하여 분석 및 시험을 수행하고 이를 바탕으로 충전 알고리즘을 개선하였다. 또한 저온시동 모사시험을 수행한 결과 저온에서의 배터리 충전 결함이 해결되었으며 충전 성능 향상이 확인되어 새로운 알고리즘의 개선을 확인하였다.

• Childhood Kidney Diseases
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• 제11권2호
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• pp.255-263
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• 2007

목 적 : 단일 기관에서 만성복막투석을 시행 받고 있는 소아 환자를 대상으로 후향적 단면연구를 시행하여 복막투석 방법에 따른 투석 결과의 차이가 있는지에 대하여 연구해 보고자 한다. 방 법 : 단일 기관에서 2004년과 2007년 사이에 복막투석을 시행 받았던 환자들 중 투석 후 3개월에서 15개월 사이에 복막투석 적절도에 대한 평가가 이루어졌던 35명의 환자를 대상으로 하였다. 연구 당시 시행하고 있던 복막투석 방법에 따라 CAPD 군, CCPD 군과 NIPD 군으로 환자들을 분류하였고 각각 17명, 13명, 5명의 환자들이 포함되었다. 각 군 사이에 항고혈압제를 복용하고 있는 환자 수, 체중, 신장 및 일반화학 검사와 혈색소 검사를 포함한 혈액 검사 결과의 차이가 있는지 비교 분석하였다. 투석 및 잔여 신기능을 통한 주간 $Kt/V_{urea}$, Ccr과 초여과양 및 소변량에 대한 비교 분석도 시행하였다. 표준 방법을 통한 복막평형검사를 시행하여 개인의 복막 투과성에 대해서도 알아보았다. 결 과 : 각 군 간에 항고혈압제를 복용하고 있는 환자의 비율, 체중과 신장 Z-score의 월간 변화 및 혈액검사 평균 수치의 차이는 유의하지 않았다. CAPD 군과 CCPD 군에서, 복막투석 및 잔여 신기능을 통한 주간 Kt/Vurea, Ccr 및 수분 배설 의 차이는 없었다. NIPD 군의 복막투석을 통한 주간 Ccr이 다른 두 군에서보다 유의하게 낮았지만, 잔여 신기능을 통한 보상으로 총 주간 Ccr에는 차이가 없었다. 복막 평형 검사 결과 저 투과성(low transporter) 및 저 평균 투과성(low average transporter)으로 분류되었던 환자들을 대상으로 비교하였을 때, CAPD를 통한 주간 Ccr이 CCPD를 통한 주간 Ccr 보다 유의하게 높았다. 결 론 : 본 연구의 결과를 토대로, 소아 만성복막투석 환자들에 있어서 투석 방법은 환자의 선호도에 의하여 자유롭게 선택될 수 있어야 할 것을 제안하는 바이다. 또한 초여과의 실패 및 부적절한 투석으로 투석 방법의 변경이 불가피한 상황에서, 복막 평형 검사는 투석 방법 변경이 적절이 이루어질 수 있도록 도와주는 귀중한 정보를 제공해 줄 것이다. 투석 방법 간의 명확한 비교를 위하여 향후 복막염의 빈도, 영양상태 및 장기간의 성장등 다양한 투석 성적을 비교하는 추가 연구가 필요할 것으로 생각된다.

• Tuberculosis and Respiratory Diseases
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• 제55권5호
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• pp.516-521
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• 2003

Aspergillus 종 특히 Aspergillus niger는 폐조직에 칼슘 옥살산 결정(oxalate crystal)을 침착시키면서 페손상을 초래하는 것으로 보고되고 있다. 저자들은 Aspergillus niger에 의해 생성된 옥살산염(oxalaic acid)에 의해 환자의 폐손상이 야기되고 그 결과 대량객혈이 발생한 것으로 추정되는 증례를 경험하였기에 보고하는 바이다. 과거에 식도암파 폐결핵으로 치료받은 적이 있는 46세 남자 환자가 고열과 간헐적 객혈, 그리고 흉부 방사선상 공동을 갖는 폐의 이상 음영을 주소로 내원하였다. 입원 후 항생제와 항결핵 치료를 병합하였지만 고열이 지속되었다. 객담 검사상 Aspergillus niger가 반복적으로 배양되어 정맥내 amphotencin B를 주입을 시작하였고, 이후 환자는 간헐적인 객혈은 지속되었으나 열은 소실되었다. 경기관지폐생검으로 얻은 조직에서 균은 동정되지 않았으나, 수많은 칼슘 옥살산 결정과 주위로 급성 염증성 삼출물이 관찰되었다. 환자는 입원 63일째 약 800ml 가량의 대량 객혈이 발생하였고, 기관지 동맥 색전술을 시행하였으나 출혈이 지속되었고 결국 호흡부전으로 사망하였다.

• Journal of Periodontal and Implant Science
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• 제48권4호
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• pp.213-223
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• 2018

Purpose: Oral lichen planus (OLP) is a chronic oral mucosal disease that has been recognized as an immune condition. The purpose of this study was to evaluate factors affecting the clinical outcomes of topical corticosteroid application on OLP lesions using dexamethasone gargle and ointment. Methods: The charts of patients who were clinically diagnosed with OLP and treated with dexamethasone from July 2003 to August 2017 at the Section of Dentistry of Seoul National University Bundang Hospital were thoroughly evaluated to identify subjects who were suitable for this retrospective study. For each patient, age at the index date, gender, medical history, and dental records related to OLP lesions and dexamethasone treatment were reviewed. Results: In total, 113 of the 225 patients were included in the present study. Among them, 79 patients were female (69.9%) and 34 were male (30.1%), with a mean age of 57.6 years. The average duration of dexamethasone treatment was 4.7 months and the mean follow-up period was 2.24 years. Improvements were observed within 1 year after dexamethasone treatment in most cases, and 17.7% of patients had a new OLP lesion after treatment. New OLP lesions were more frequently gingival than mucosal, although mucosal OLP lesions were more common than gingival OLP lesions in all age groups. In age- and gender-adjusted multivariate logistic regression, a history of malignant disease was found to be a significant factor affecting the formation of new lesions. Gingival OLP lesions and intermittent use of dexamethasone showed near-significant associations. In Kaplan-Meier failure analysis, history of malignancy, menopausal status, age, and the site of the OLP lesion were significant factors affecting clinical outcomes. Conclusions: The treatment outcomes of OLP were significantly influenced by age, history of malignancy, menopausal status, and the site of the OLP lesion, but not by factors related to dexamethasone treatment.