• Journal of Chest Surgery
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• v.36 no.8
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• pp.559-565
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• 2003

By improving the flow pattern in Fontan circuit, total cavopulmonary connection (TCPC) could result in a better outcome than atriopulmonary connection Fontan operation. For the patients with impaired hemodynamics after atriopulmonary Fontan connection, conversion to TCPC can be expected to bring hemodynamic and functional improvement. We studied the results of the revision of the previous Fontan connection to TCPC in patients with failed Fontan circulation. Material and method: From October1979 to June 2002, eight patients who had failed Fontan circulation, underwent revision of previous Fontan operation to TCPC at Yonsei University Hospital. Intracardiac anomalies of the patients were tricuspid atresia (n=4) and other functional single ventricles (n=4). Mean age at TCPC conversion was 14.0$\pm$7.0 years (range, 4.6~26.2 years) and median interval between initial Fontan operation and TCPC was 7.5 years (range, 2.4~14.3 years). All patients had various degree of symptoms and signs of right heart failure. NYHA functional class was 111 or IV in six patients. Paroxysmal atrial fibrillation (n:f), cyanosis (n=2), intraatrial thrombi (n=2), and protein losing enteropathy (PLE) (n=3) were also combined. The previous Fontan operation was revised to extracardiac conduit placement (n=7) and intraatrial lateral tunnel (n=1). Result: There was no operative death. Major morbidities included deep sternal infection (n=1), prolonged pleural effusion over two weeks (n=1), and temporary junctional lachyarrhythrnia (n=1). Postoperative central venous Pressure was lower than the preoperative value (17.9$\pm$3.5 vs. 14.9$\pm$1.0, p=0.049). Follow-up was complete in all patients and extended to 50,1 months (mean, 30.3$\pm$ 12.8 months). There was no late death. All patients were in NYHA class 1 or 11. Paroxysmal supraventricular tachycardia developed in a patient who underwent conversion to intraatrial lateral tunnel procedure, PLE was recurred in two patients among three patients who had had PLE before the convertsion. There was no newly developed PLE. Conclusion: Hemodynamic and functional improvement could be expected for the patients with Fontan circulatory failure after atriopulmonary connection by revision of their previous circulation to TCPC. The conversion could be performed with low risk of morbidity and mortality.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.158-161
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• 2004

In order for better management of a medical linear accelerator, the records of the operational failures of Varian CL2100C over ten years were analyzed. The failures were classified according to the involved functional subunits and each class was rated into three levels depending on operational conditions. The relationship between the failure rate and working ratio was investigated. Among the recorded failures ( total 587 failures), the most frequent failure, which was 20% of the total. was observed in the parts related to the collimation system including monitor chamber. Regrading to the operational conditions, the 2nd level of failures, that temporally interrupted treatments, was the most frequent. The 3rd level of failures, that interrupted treatment for more than several hours, was mostly caused by the accelerating subunit. The average life-time of a Klystron and Thyratron became shorter as the working ratio increased, which was 42 and 83% of the expected values, respectively. Recording equipment problems and failures in detail over a long period of time can provide a good knowledge of equipment function as well as the capability to forecast future failure. More rigorous equipment maintenance is required for old medical linear accelerator to avoid the serious failure in advance, and improve the patient treatment quality.

• The KIPS Transactions:PartD
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• v.13D no.5 s.108
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• pp.709-716
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• 2006

As the software complexity increases, the development success rate decreases and failure rate increases exponentially. The failure rate related to the software size can be described by a growth function. Based on this phenomenon, this paper estimates the development success and completion rate using the Gompertz growth function. At first, we transformed a software size of numerically suggested $10^n$ into a logarithm and kept the data interval constantly. We tried to derive a functional relationship between the development success rate and the completion rate according to the change of logarithmic software size. However, we could not find a function which can represent this relationship. Therefore, we introduced the failure rate and the cancel rate which are inverse to the development success rate and completion rate, respectively. Then, we indicated the relation between development failure rate and cancel rate based on the change of software size, as a type of growth function. Finally, as we made the Gompertz growth function with the function which describes the cancel rate and the failure rate properly. We could express the actual data suitably. When you apply the growth function model that I suggested, you will be able to get the success rate and completion rate of particular site of software very accurately.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.6
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• pp.408-411
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• 2013

After radical excision of a tumor in the maxillofacial area, functional and esthetic reconstruction is needed, including flap surgery. Among the many etiologies of flap failure, venous thrombosis is one of the most frequent. Heparin is used routinely in the effort to avoid development of venous thrombosis. In rare cases, heparin-induced thrombocytopenia (HIT) type II occurs due to exposure to heparin. Heparin attached to platelet factor 4 forms a PF4/heparin-immunoglobulin G immune complex on platelet surfaces. This complex activates platelets, which leads to multiple coagulation in venous and arterial blood. We report here on a rare occurrence of HIT type II following fibula free flap surgery.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2723-2725
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• 2014

Recently we have reported a novel class of anion receptors which are based on 2n-crown-n topology. Trioxane derivatives are capable of anion sensing through pure aliphatic C-H hydrogen bonding. In this work, we highlight another interesting property, i.e., they can also recognize cations as normal crown ethers (3n-crown-n topology). Since the same functional moiety can recognize anions and cations, these coronands are predicted to be amphi-ionophores. However, we could not detect cations even in the gas phase. Considering trioxane is analogous to [$1_6$]starand, this was rather counter-intuitive. The calculation results show that these coronands can detect alkali metals with very low affinity. The low affinity toward cations should be responsible for this failure of experimental detection. With careful theoretical study, we found that this low affinity toward cations could be explained by the unfavorable charge-dipolar moiety orientations as proposed by Cui et al. As in the case of [$1_6$]starand, this is an example that underscores the importance of charge-dipolar moiety orientation in supramolecular interactions.

• Journal of Korean Foot and Ankle Society
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• v.22 no.2
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• pp.49-54
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• 2018

Ankle sprains are among the most common injuries sustained during athletic activities and daily life. Acute ankle sprain is usually managed conservatively with functional rehabilitation but the failure of conservative treatment leads to the development of chronic ankle instability. The development of repetitive ankle sprains and persistent symptoms after injury has been termed chronic ankle instability. Acute ankle sprains and chronic ankle instability require a careful evaluation to detect other comorbidities, such as subtalar instability, osteochondral defect, peroneal tendinopathy, tarsal coalition, os trigonum, flexor hallucis longus tendinitis, calcaneus anterior process fracture, and neural injuries. For the successful treatment of acute ankle sprains and chronic ankle instability, the treatment of comorbidity lesions should be performed first.

• Journal of Chest Surgery
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• v.27 no.9
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• pp.759-763
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• 1994

Between November 1990 and December 1993, 9 patients underwent surgical intervention for acute active endocarditis at Gyeongsang National University Hospital. All the patients were operated on within the first six weeks after onset of symptoms for various reasons. Surgical indications for early surgery were heart failure, systemic septic emboli, new murmur and growing vegetation. Most common infecting organism was Staphylococcus[55 %], and the others were Streptococcus, anaerobes, Candida and unknown in 1 case. The infection was in the mitral valve in 5 patients, the aortic valve in 2, the aortic and mitral in 1, and the aortic and pulmonary in 1. There was one operative death[11 %] and no late death. Preoperative Functional Class were II in 4 patients, III in 5 and after surgery all the patients improved to Class I. We conclude that early surgical intervention in acute active endocarditis is effective in most instances.

• Journal of Chest Surgery
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• v.18 no.3
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• pp.414-422
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• 1985

Truncus arteriosus is one of the rare cyanotic congenital cardiac anomalies and thought to be result from complete or partial failure of trunco-conal septum. A single arterial trunk receiving blood from both ventricles supplies the coronary, pulmonary and systemic circulation. The symptoms were usually related to the degree of the pulmonary blood flow and functional status of truncal valve, and mostly appeared within the first two months of life. The prognosis is generally considered to be poor in spite of successful surgical correction. This report is a case of 13 years old female with type I truncus arteriosus, which was successfully corrected using a intracardiac Dacron tunnel graft[semilunar, 18mm] from VSD to the truncal valve, and a extra-cardiac lonescu-Shiley valved[20mm] Dacron conduit [21mm] from RV to the pulmonary artery[Rastelli operation].

• Childhood Kidney Diseases
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• v.13 no.1
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• pp.14-20
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• 2009

Growth retardation is a common consequenc of chronic kidney disease (CKD) in childhood. Many recent clinical and experimental data indicate that growth failure in CKD is mainly due to a relative GH insensitivity and functional IGF-I deficiency. Glucocorticoids also glucocorticoids interfere with the integrity of the somatotropic hormone axis at various levels. Over the past 10 years, recombinant growth hormone (rhGH) has been used to help short children with chronic kidney disease. A GH dosage of 0.35 mg/kg/week (28 IU/$m^2$/week) appears efficient and safe. Some clinical trial data show that final height will be within the normal target height range when GH treatment is continued for many years without remarkable adverse events.

• Journal of the Korean Society of Systems Engineering
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• v.11 no.1
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• pp.67-72
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• 2015

It has been tested for SW reliability in order to prevent the SW error during the development of weapons systems. According to a recent report, defects such as memory leak, buffer overflow, and null deference occur usually in the development stage, but also in the mass production stage. Although it is intended to enhance the SW test and evaluation to prevent SW failures in the development stage, the non-functional problems like syntax errors are not completely revised due to the limitation of the schedule and costs. In addition, SW failure rate are usually fluctuated by the operational environment through SW upgrade in contrast with HW. In this paper, we propose a method to increase SW reliability in the mass production stage of Korean weapon systems.