• Tuberculosis and Respiratory Diseases
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• v.44 no.6
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• pp.1366-1381
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• 1997

Background : Uvulopalatopharyngoplasty(UPPP) has become the most common surgical treatment for obstructive sleep apnea syndrome(OSAS). However, the results of this therapeutic modality have been quite variable with successful results by several authors and poor results by others. Until recently, in Korea, there is only a few reports about the clinical efficacy of UPPP. A prospective study was undertaken to evaluate the effectiveness and complications of UPPP. Method : Twenty-six OSAS patients who had undergone UPPP with preoperative and postoperative polysomnographic studies were included in this study. Two definitions of surgical success were used. The responder was defined, using a conventional criteria, as a 50% or more reduction in apnea index(AI) or apneahypopnea index(AHI) after UPPP, or a postoperative AI of <10 or AHI of <20. The initial cure was defined, using our own criteria, as a postoperative AI of <5 or AHI of <10. Complications were categorized in two groups : early(disorders during the first 10 postoperative days) and late. Results : Eighteen patients(69.2%) were responders, and ten patients(38.5%) were considered as initial cure. On the other hand, in five patients (19.2%), postoperative polysomnographic data demonstrated deterioration compared with preoperative data. Reduction rate of AI or AHI following UPPP was not significantly related to the preoperative body mass index, AI or AHI. There was no significant change of sleep architecture before and after UPPP in responder and initial cure groups. Early complications such as pain, dyspnea, bleeding, nasal reflux, dysphagia or wound disruption were observed in all patients. Late complications such as nasal reflux, voice change, dysphagia, loss of taste, pharyngeal dryness or foreign body sensation were discovered in 22 patients (84.6%). However, all early and late complications were of minor importance. Conclusion : The response to UPPP was favorable in approximately 70% of OSAS patient. However, the initial Cure rate of UPPP was relatively low. We suggest that selection of more appropriate surgical candidates and adequate surgical protocol is necessary to obtain a more successful result with UPPP.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.115-125
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• 2009

Purpose: The purpose of the study is to evaluate the usefulness of CT arthrography (CTA) by conducting a comparative study of CTA and MR arthrography (MRA) with the arthroscopic findings in the same patients. Materials and methods: Forty nine patients who suffered from shoulder disease underwent MRA and CTA concurrently. The sensitivity and specificity of CTA was evaluated, as compared to MRA, in the case of four types of shoulder pathological lesions. The accuracy of CTA was evaluated by analyzing the arthroscopic findings of thirty four patients. Results: Compared to MRA, CTA showed a sensitivity of 90% and a specificity of 100% for diagnosing supraspinatus tendon (SST) full thickness tear, and CTA showed a sensitivity of 100% and a specificity of 97.5% for making the diagnosis of superior labrum anterior to posterior (SLAP) lesion. For diagnosing partial articular side supraspinatus avulsion (PASTA) lesion, some studies have shown the usefulness of CTA with a sensitivity of 71.4% and a specificity of 97.7%. However, for diagnosing SST bursal side partial tear, the sensitivity of CTA was as low as 10%. CTA has been shown to be relatively accurate when the diagnoses were verified with the arthroscopic findings; diagnosing SST full thickness tear and SLAP lesion with CTA has shown an accuracy of 100% and87.5% respectively, and CTA showed 71.4% diagnostic accuracy for PASTA lesion. Conclusion: CTA was a useful tool and it was equivalent to MRA for the assessment of SST full thickness tear, SLAP lesion and PASTA lesion, but not bursal side partial tear. Thus, it may be used preferably to diagnose shoulder pathology and for follow up as an inexpensive tool after operation.

• Childhood Kidney Diseases
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• v.9 no.1
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• pp.64-68
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• 2005

Purpose : Renal abscess is very rare in children and its diagnosis is difficult because symptoms are often nonspecific. In previous studies, on]y 15% to 25% of patients were reported to be diagnosed at the time of admission. Early diagnosis and treatment are important be cause mortality rate correlates positively with the time of diagnosis. The purpose of this study is to clarify the clinical features of children with renal abscess and to investigate the possible indicators of this disease for early diagnosis and Proper treatment. Methods : Twelve children diagnosed with renal abscess from Jan. 1996 to Jul. 2004 were included. The age of patients ranged from S months to 15 years. We retrospectively analyzed the demographics of patients, their symptoms, predisposing factors, diagnostic methods and causative organisms and the treatment modalities. Results : Fever was the most common manifestation, Five children(42%) had vesicoureteral reflux. Renal ultrasonography and computerized tornography were the most frequently used imaging tools to detect renal abscess. Gram negative bacteria were isolated in 7 patients and Staphylococcus aureus grew in 2 patients. All patients received intravenous antibiotics and 4 patients underwent aspiration or drainage of renal abscess. The average admission duration was 30 days. Conclusion : Renal abscess should be included in the differential diagnosis of prolonged fever in children, especially when flank pain is combined. For early diagnosis and a better prognosis, patients should be promptly investigated with ultrasonography or computerized tomography.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.9-18
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• 2024

The importance of active sonar systems is emerging due to the quietness of underwater targets and the increase in ambient noise due to the increase in maritime traffic. However, the low signal-to-noise ratio of the echo signal due to multipath propagation of the signal, various clutter, ambient noise and reverberation makes it difficult to identify underwater targets using active sonar. Attempts have been made to apply data-based methods such as machine learning or deep learning to improve the performance of underwater target recognition systems, but it is difficult to collect enough data for training due to the nature of sonar datasets. Methods based on mathematical modeling have been mainly used to compensate for insufficient active sonar data. However, methodologies based on mathematical modeling have limitations in accurately simulating complex underwater phenomena. Therefore, in this paper, we propose a sonar signal synthesis method based on a deep neural network. In order to apply the neural network model to the field of sonar signal synthesis, the proposed method appropriately corrects the attention-based encoder and decoder to the sonar signal, which is the main module of the Tacotron model mainly used in the field of speech synthesis. It is possible to synthesize a signal more similar to the actual signal by training the proposed model using the dataset collected by arranging a simulated target in an actual marine environment. In order to verify the performance of the proposed method, Perceptual evaluation of audio quality test was conducted and within score difference -2.3 was shown compared to actual signal in a total of four different environments. These results prove that the active sonar signal generated by the proposed method approximates the actual signal.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.164-171
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• 1997

Heart transplantation is now accepted as a definitive therapeutic modality in patients with terminal hear failure. The first successful heart transplantation in humans was done in 1967 and the first case in Korea was performed in november, 1992. Since the first case in 1992, more than 50 cases have been performed in Korea. A total of 20 patients underwent orthotopic heart transplantation since November, 1992 in Asan Medicla Center. The purpose of this study is to evaluate the early results and the follow-up course of 20 cases of heart transplantation done in Asan Medical Center. The average age of 20 patients was 39.9$\pm$11.8 years old(20~58). The mean follow-up duration was 14.4$\pm$11.2 months(1~41). All patients are alive till now. The blood type was identical in 14 and compatible in 6 patients. ihe original heart disease was dilated cardiomyopathy in 16, valvular heart disease in 2, ischemic cardiomyopathy in 1, and giant cell myocarditis in 1 patient. HLA cross matching for recipient and donor was done in 18 cases and the results were negative for T-cell and B-cell in 16 patients, pos tive for warm B-cell in 2 patients. Among 6 loci of A, B, and DR, one locus was matched in 8 cases, 2 loci in 5 cases, and 3 loci matched in 1 case. The number of acute allograft rejection averaged 2.8$\pm$0.5 (0~6) per case and the number of acute allograft rejection requiring treatment averaged 1.0$\pm$0.9 (1~3) per case. The time interval from operation to the first acute rejection requiring treatment was 35.5$\pm$20.4 days (5~60). Acute humoral rejection was suspected strongly in 1 case and was successfully treated. The left ventricular ejection fraction measured by echocardiography and/or MUGA scan was dramatically increased from 17.5$\pm$6.8 (9~32)% to 58.9$\pm$2.0 (55~62)% after heart transplantation. Temporary pacing was needed in 5 patients over 24 hours but normal sinus rhythm appeared within 7 days in all cases. One patient has been taken permanent pacemaker implantation due to complete AV block appearing 140 days after heart transplantaion. One patient had cyclosporine-associated n urotoxicity during the immediate postoperative period and was recovered after 27 hours. The heart transplantation of Asan Medical Center is on a developing stage but the early result is comparable to that of well established centers in other countries, even though the long-term follow-up result must be reevaluated. We can conclude that the heart transplantion is a promising therapeutic option in patients with terminal heart failure.