• Journal of Korean Neurosurgical Society
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• 제65권4호
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• pp.531-538
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• 2022

Objective : Anterior communicating artery (Acom) aneurysm is one of the most common intracranial aneurysms, constituting approximately 30-35% of all aneurysm formation in the brain. Anatomically, the H-complex (the anatomic morphology of both A1 to A2 segments) is thought to affects the nature of the Acom aneurysm due to its close relationship with the hemodynamics of the vessel. Therefore, we investigated the relative risk factors of aneurysmal rupture, especially focusing on H-complex morphology of the Acom. Methods : From January 2016 to December 2020, a total of 209 patients who underwent surgery, including clipping and coiling for Acom aneurysm in our institution were reviewed. There were 102 cases of ruptured aneurysm and 107 cases of unruptured aneurysm. The baseline morphology of aneurysms was investigated and the relationship between the H-complex and the clinical characteristics of patients with Acom aneurysms was assessed. Results : Of the 209 patients, 109 patients (52.1%) had symmetrical A1, 79 patients (37.8%) had unilateral hypoplastic A1, and 21 patients (10.0%) had aplastic A1. The hypoplastic A1 group and the aplastic A1 group were grouped together as unilateral dominancy of A1, and were compared with the symmetrical A1 group. There was no significant difference in demographic characteristics and radiological findings of Acom aneurysms between two groups. However, when dichotomizing the patients into ruptured cases and unruptured cases, unilateral dominance of the A1 segment was associated with aneurysmal rupture with statistical significance (p=0.011). Conclusion : These results suggest that the unilateral dominance of the A1 segment does not have a significant effect on the morphology of Acom aneurysms, but contributes to aneurysmal rupture. Thus, we can better understand the effects of hemodynamics on Acom aneurysm.

• Journal of Chest Surgery
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• 제47권1호
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• pp.71-74
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• 2014

For high-risk patients, endovascular aortic aneurysm repair (EVAR) is a good option but may lead to serious complications, which should be addressed immediately. A 75-year-old man with a history of abdominal surgery underwent EVAR for an aneurysm of the abdominal aorta and iliac arteries. During EVAR, iliac artery rupture and graft limb occlusion occurred, and they were successfully managed by the additional deployment of an iliac stent graft and balloon thrombectomy, respectively. We, herein, report a rare case of the simultaneous development of the two fatal complications treated by the endovascular technique.

• Journal of Chest Surgery
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• 제44권1호
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• pp.76-79
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• 2011

Right-sided diaphragmatic rupture is less common and more difficult to diagnose than left-sided lesion. It is rarely combined with the herniation of the abdominal organs into the thorax. High level of suspicion is the key to early diagnosis, and a delay in diagnosis is implicated with a considerable risk of mortality and morbidity. We experienced a case of right-sided diaphragmatic rupture combined with complete avulsion of the right kidney and herniation of the liver into the thoracic cavity.

• Nuclear Engineering and Technology
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• 제51권8호
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• pp.1939-1950
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• 2019

The MELCOR code useful for a plant-specific hydrogen risk analysis has inevitable limitations in prediction of a turbulent flow of a hydrogen mixture. To investigate the accuracy of the hydrogen risk analysis by the MELCOR code, results for the turbulent gas behavior at pipe rupture accident were compared with CFX results which were verified by the American National Standard Institute (ANSI) model. The postulated accident scenario was selected to be surge line failure induced by station blackout of an Optimized Power Reactor 1000 MWe (OPR1000). When the surge line failure occurred, the flow out of the surgeline was strongly turbulent, from which the MELCOR code predicted that a substantial amount of hydrogen could be released. Nevertheless, the results indicated nonflammable mixtures owing to the high steam concentration released before the failure. On the other hand, the CFX code solving the three-dimensional fluid dynamics by incorporating the turbulence closure model predicted that the flammable area continuously existed at the jet interface even in the rising hydrogen mixtures. In conclusion, this study confirmed that the MELCOR code, which has limitations in turbulence analysis, could underestimate the existence of local combustible gas at pipe rupture accident. This clear comparison between two codes can contribute to establishing a guideline for computational hydrogen risk analysis.

• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1307-1313
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• 2019

Recent analysis results with realistic assumptions provide the variability of operator allowable time for the initiation of aggressive cooldown under small break loss of coolant accident or steam generator tube rupture with total failure of high pressure safety injection. We investigated how plant risk may vary depending on the variability of operators' failure probability of timely initiation of aggressive cooldown. Using a probabilistic safety assessment model of a nuclear power plant, we showed that plant risks had a linear relation with the failure probability of aggressive cooldown and could be reduced by up to 10% as aggressive cooldown is more reliably performed. For individual accident management, we found that core damage potential could be gradually reduced by up to 40.49% and 63.84% after a small break loss of coolant accident or a steam generator tube rupture, respectively. Based on the importance of timely initiation of aggressive cooldown by main control room operators within the success criteria, implications for improvement of emergency operating procedures are discussed. We recommend conducting further detailed analyses of aggressive cooldown, commensurate with its importance in reducing risks in nuclear power plants.

• 대한영상의학회지
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• 제84권3호
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• pp.750-756
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• 2023

자발적 동맥 출혈은 드물며, 속가슴동맥의 자발적 파열에 의한 혈종은 이전에 보고된 바가 없다. 간경화증이 있거나 과음하는 환자는 출혈의 위험성이 더 큰 것으로 알려져 있다. 저자들은 알코올성 간경화증을 가진 39세 여성에서 자발적 속가슴동맥 출혈로 인해 발생한 거대한 종격동 혈종의 증례를 보고하고자 한다.

• Journal of Korean Neurosurgical Society
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• 제45권2호
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• pp.85-89
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• 2009

Objective : The International Study of Unruptured Intracranial Aneurysms (ISUIA) reported that the 5-year cumulative rupture rate of small unruptured aneurysms less than 7 mm in diameter is very low depending on the aneurysm's location. However, we have seen a large number of ruptured aneurysms less than 7 mm in clinical practice. The purpose of this study was to review our experience and to measure the size and location at which aneurysms ruptured in our patient population. Methods : We reviewed the characteristics of aneurysms, such as size and location, from the original angiograms of patients who were admitted to our hospital between January 2004 and December 2007. All aneurysms were treated surgically or through endovascular procedures. Results : Interventional or surgical treatment was given to a total of 889 patients, including 568 females and 321 males. At the time of our study, 627 cases were ruptured aneurysms and 262 cases were unruptured aneurysms. Of the ruptured cases, the mean diameter of the aneurysm was 6.28 mm. We found that 71.8% of ruptured aneurysms were smaller than 7 mm in diameter, and 87.9%, were smaller than 10 mm. Based on location, the data show that anterior communicating artery aneurysms most often presented with rupture sizes less than 7 mm (76.8%) and 10 mm (92.1%) in diameter. Most ruptured aneurysms were less than 7 mm in size, although recent studies have noted that small aneurysms are less likely to rupture. Conclusion : Although the natural history of unruptured intracranial aneurysms remains controversial, the aneurysm size and location play a signigicant role in determining the risk of rupture. Larger sample sizes and a long term study are needed to reveal the natural history and the rupture risk of unruptured intracranial aneurysms because the size of most ruptured aneurysms was less than 7 mm in diameter in our series.

• Journal of Chest Surgery
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• 제37권9호
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• pp.774-780
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• 2004

외상성 흉부대동맥 파열은 수술적 치료가 요구되는 치명적 손상이며 이외에 다른 부위에 복합손상이 동반되면 심폐 바이패스에 의한 위험도를 크게 증가시킬 수 있다. 여기서 저자들은 심한 동반손상을 먼저 치료한 후 대동맥수술을 하고 그 결과를 관찰하였다. 대상 및 방법: 1997년부터 2003년까지 외상성 흉부 대동맥질환으로 수술을 받은 24명의 환자를 대상으로 의무기록을 후향적으로 검토하여, 동반손상 여부, 수술방법, 수술 후 경과, 합병증 등을 분석하고 국내외 문헌들과 비교하였다. 수술은 초저온 심정지법하에서 심폐 바이패스를 이용한 개흉술로 하였는데 근위부 연결 후 곁가지를 통해 뇌관류를 시행하였고 요추 카테터를 통한 뇌척수액 배액으로 하반신 마비를 예방하였다. 결과： 대상환자 전원에서 83예의 동반손상이 발생하였는데, 흉부손상이 49예, 근골격계 손상 18예, 복부 손상 13예였고, 수상 후 12명의 환자에서 7.6$\pm$12.6일에 16예의 동반손상에 대한 수술이 행해졌다. 수상당시 18예에서만 대동맥 손상이 진단되었다. 중환자실에서 혈압을 약물투여로 조절하면서 안정시키고 수상 후 693 $\pm$ 1350일에 지연수술을 시행하였는데, 관찰기간 중 사망이나 대동맥 파열의 진행은 없었다. 수술 사망은 없었으며, 술 후 큰 합병증은 없었다. 결론： 외상성 흉부대동맥 파열에 있어서 다른 부위 손상이 동반되면 심한 동반손상을 먼저 치료한 후 수술하는 것이 수술 사망률이나 이병률 면에서 좋은 결과를 가져온다.

• Nuclear Engineering and Technology
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• 제49권2호
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• pp.313-326
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• 2017

The systematic management of plant risk is crucial for enhancing the safety of nuclear power plants and for designing new nuclear power plants. Accident sequence precursor (ASP) analysis may be able to provide risk significance of operational experience by using probabilistic risk assessment to evaluate an operational event quantitatively in terms of its impact on core damage. In this study, an ASP methodology for two operation mode, full power and low power/shutdown operation, has been developed and applied to significant accident precursors that may occur during the operation of nuclear power plants. Two operational events, loss of feedwater and steam generator tube rupture, are identified as ASPs. Therefore, the ASP methodology developed in this study may contribute to identifying plant risk significance as well as to enhancing the safety of nuclear power plants by applying this methodology systematically.

• Clinics in Shoulder and Elbow
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• 제5권2호
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• pp.73-80
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• 2002

Purpose: Weight lifting is a good training to control body weight, to correct body shape and to relieve stress. How-ever if the training is continued by inadequate training method and technique, the risks of the shoulder injuries are relatively high. Main Subject: The rotator cuff injury is the most common disorder to wright lifters and often results from the train- ing program of upright row, military press and pectoral deck. The chances of subacromial impingement in these postures are high because the shoulder rotates under the acromion at 90 abduction state. Shoulder instability in weight lifters can develop due to various causes. aepeated microtrauma and excessive abduction and external rotation may result in laxity of the anterior capsular structure, ligament and muscles. Behind the neck and bench press are high risk training postures. Other than those injuries, idiopathic osteolysis of distal clavicle, acromioclavicular separation, pectoralis major muscle rupture, and triceps muscle rupture nay develop. Conclusion: The best treatment option of the shoulder injury to weight lifters is to eliminate the possible risk elements for the weight lifters in training program and to provide proper and prompt treatment as soon as possible.