• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.252-253
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• 2004

원자력발전소를 가동한지 25년이 지나고 있는 현재 방사성 폐기물에 대한 대책이 시급한 실정이다. 가동한지 오래된 국내 원자력발전소의 경우 가까운 장래에 일차 냉각 계통의 제염이 요구될 것이며, 특히 앞으로 해체를 해야 할 시설들이 생기고 철거를 해야 할 필요성이 제기 되면서 엄청나게 발생할 금속 폐기물의 처리에 대한 문제가 주목을 받고 있다. 금속 폐기물의 처리를 위해 부피를 최소화하여 처분 관리하는 방법과 금속 폐기물을 제염하여 재사용하는 방법 등이 고려되고 있다.(중략)

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.145-152
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• 1999

Purpose: The prevalence of childhood renal diseases including the nephrotic syndrome in Korea has not been well established. In priority to this point, we analyzed ninety-six nephrotic children of the annual incidence, the ratio of them to all inpatients and estimated incidence of childhood nephrotic syndrome under 15 years of age in Taejon, Korea. Also we classified them by clinical and histopathological findings. Methods: we analyzed the admission and outpatient records retrospectively between June 1986 and December 1998. For the estimation of incidence, we were assisted with three other general hospitals in Taejon Results: The mean annual number and the ratio to inpatients were $7.4{\pm}2.1,\;0.3{\pm}0.11%$ respectively. The latter showed a tendency to decrease during the recent three years. The estimated annual incidences of childhood nephrotic syndrome in Taejon were 5.6 in 1988, 5.5 in 1993 and 4.8 in 1998 per 100,000 for children aged up to 15 years. The mean age of our patients was $6.8{\pm}3.5$ tears, 1-7 years of age was 55 cases(57.3%), and male to female ratio was 3.6:1. By the clinicopathologic classification, 89 cases(92.7%) were classified as primary nephrotic syndrome, and 7 cases(7.3%) as secondary nephrotic syndrome. Among the primary nephrotic syndrome, there was 79.8% of minimal change nephrotic syndrome, focal segmental glomerulosclerosis 11.2%, mesangial proliferation 4.5%, membranoproliferative glomerulonephritis 3.4%, and membranous nephropathy 1.1%. $Henoch-Sch\"{o}nlein$ nephritis was the most frequent of 3 cases in the secondary nephrotic syndrome. Respones to steroid therapy of 71 cases minimal change were classified as non-relapse 22.5%, non-frequent relapse 49.3%, frequent relapse 18.3% and steroid-dependence 9.9%. Conclusion: The estimated incidence of childhood nephrotic syndrome was about 5 per 100,000 for children aged up to 15 years and it showed little changes during 10 years in Taejon, Korea. Our results of clinicopathologic study was little difference from the results reported in other literatures.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.646-654
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• 2013

In this study, quantitative analysis of major volatile flavor compounds from yogurt was conducted using headspace-solid phase microextraction (HS-SPME) GC-FID analysis technique, and the changes of volatile aroma compounds during the storage period were evaluated. The yogurt was prepared with the addition of 2% cereals, such as, white rice (WR), brown rice (BR), germinated brown rice (GBR) and saccharified germinated brown rice (SGBR). After fermentation, the products were stored at $5^{\circ}C$for 15 d. The major volatile aroma compounds in yogurt, such as acetaldehyde, acetone, diacetyl and acetoin were able to be extracted using HS-SPME technique efficiently. The regression ($r^2$) value of standard curve prepared with various concentrations of individual flavor chemicals was analyzed over 0.9975, and reproducibility was acceptable to apply quantitative analysis. The analysis of volatile components of control sample during storage showed that the acetaldehyde on 0 d was 10.83 ppm, and that contents were increased to 15.67 ppm after 15 d of storage. However, addition of BR, GBR and SGBR decreased the acetaldehyde contents during storage periods. The acetone content of all treatments during storage was not significantly different. The diacetyl content of all treatments were increased during storage and the addition of SGBR showed the highest amount of diacetyl (0.84 ppm) among treatments on 15 d of storage. The acetoin content of yogurt added with grains was higher than that of control during storage. As a result, the content of volatile aroma compounds in yoghurt during storage period could be analyzed HS-SPME extraction technique effectively, and HS-SPME/GC analysis can be considered for quality control of fermented milk products.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.395-398
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• 1997

Whole body $^{99m}Tc-MIBI$ scan in conjunction with parathyroid scan is an effective method in detecting parathyroid lesions in patients with bone pain and possible bone lesions such as brown tumors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6C
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• pp.523-531
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• 2005

We derive decision regions of the maximum likelihood(ML) and suboptimum ML(S-ML) detectors in the first order moving average(FOMA) of an impulsive process. The ML and S-ML detectors are compared in terms of the bit-error-rate in the antipodal signaling system. Numerical results show that the S-ML detector, despite its reduced complexity and simpler structure, exhibits practically the same performance as the optimum ML detector. It is also shown that the performance gap between detectors for FOMA and independent and identically distributed noise becomes larger as the degree of noise impulsiveness increases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.59-59
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• 2007

최근 GaN계 LED를 대체할 만한 물질로 주목받고 있는 ZnO는 단결정 박막성장의 어려움, 동일접합 LED 소자구현을 위한 p-ZnO 성장의 어려움 3원계 합금제작의 어려움 등으로 소자제작에 있어 고전을 하고 있다. 특히 이러한 문제점을 극복하고자 하는 방안으로 양자 제한 효과, 탁월한 결정성, self-assembly, internal stress 등의 새로운 기능성을 지닌 ZnO 나노구조가 제시되었다. 하지만 나노구조를 이용한 다이오드 제작에서도 금속전극의 접합이라는 문제의 벽에 가로막혀 있다. 본 실험에서는 자체 개발된 MOCVD 장비를 이용한 일차원 ZnO 나노선을 성장한 이후 연속적으로 박막을 성장하여 금속전극의 접합을 시도하였다. 이종접합구조 뿐만 아니라 일차원 및 이차원 구조의 복합구조는 일반 다결정 박막보다 결정성에서 우수한 특성을 보였으며, 다이오드 제작시에 높은 효율을 보였다.

• Pediatric Infection and Vaccine
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• v.27 no.3
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• pp.190-197
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• 2020

Laryngotracheobronchitis (LTB) is a common disease in the pediatric population, and it is rarely caused by a fungal infection. Acute respiratory failure caused by fungal LTB mainly occurs in immunocompromised patients, and early diagnosis is closely associated with morbidity and mortality. However, an appropriate diagnosis is challenging for pediatricians because symptoms and signs of LTB caused by Aspergillus spp. are nonspecific. Here, we report a case of progressive respiratory failure caused by pseudomembranous LTB in a child with a suspicion of primary immunodeficiency and highlight the importance of an early investigation, especially in immunocompromised patients.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.25-32
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• 2000

Purpose: This retrospective study of 126 children with symptomless primary hematuria was undertaken to determine the distribution of various histologic types by renal biopsy, clinical outcome according to the biopsy findings and also to find out feasibility of performing renal biopsy in these children. Patients and Methods : Study population consisted of 126 children with symptom-less primary hematuria who have been admitted to the pediatric department of Kyung-poot National University Hospital for the past 11 years from 1987 to 1998 and renal biopsy was performed percutaneously. Hematuric children with duration of less than 6 months, evidences of systemic illness such as SLE or Henoch-Schonlein purpura, urinary tract infection, and idiopathic hypercalciuria were excluded from the study. Results : Mean age of presentation was 9.2${\pm}$3.3 years (range ; 1.5-15.3 years) and male preponderance was noted with male to female ratio of 2:1. IgA nephropathy was the most common biopsy finding occuring in 60 children ($47.6\%$), followed by MsPGN in 13 ($10.3\%$), MPGN in 5 ($3.9\%$), TGBM in 6 ($4.7\%$), Alport syndrome in 2 ($1.6\%$), FSGS in 1 ($0.8\%$), and in 39 children ($30.9\%$), 'normal' glomeruli were noted. Recurrent gross hematuria was more common than persistent microscopic hematuria (84 versus 42), and especially in IgA nephropathy, recurrent gross hematuria was the most prevalent pattern of hematuria. In 58 out of 126 cases ($46.0\%$), hematuria was isolated without accompa-nying proteinuria and this was especially true In cases of MsPGN and 'normal' glomer-uli by biopsy finding. Normalization of urinalysis (disappearance of hematuria) in IgA nephropathy, MsPGN and 'normal' glomuli group were similar and it was $14\%,\;27\%\;and\;21\%$ respectively during 1-2 years of follow-up period, and $37.1\%,\;40\%\;and\;35\%$ respectively during 3-4 years of follow-up periods. However, abnormal urinalysis persi-sted in the majority of children with MPGN, TGBM. Alport syndrome and FSGS. Renal function deteriorated progressively in 6 cases (3 with IgA nephropathy, 2 with Alport syndrome and 1 with TGBM). Conclusion : In summary, present study demonstrates that in 126 children with symptomless primary hematuria, IgA nephropathy was the most common biopsy findings followed by MsPGN, MPGN, TGBM, Alport syndrome and FSGS, and 'normal glomeruli' was also seen in 39 cases ($30.9\%$). Renal histology could not be predictable on the clinical findings, so that to establish appropriate long-term planning for these children, we would recommend to obtain precise histologic diagnosis by renal biopsy.

• Sleep Medicine and Psychophysiology
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• v.7 no.2
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• pp.102-108
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• 2000

Objectives: Parkinson's disease (PD) patients may experience fluent mobility upon awakening from a night's sleep, which is called sleep benefit (SB). Although SB is a phenomenon closely associated with sleep, sleep features of PD are not well characterized. The objectives of this study were, first, to investigate if there are any clinical characteristic features between patients with SB and without SB (NSB), and second, to examine if SB patients are associated with any specific sleep variables compared with NSB patients. Methods: Thirty-three PD patients (14 men and 19 women) participated in this study. All subjects were interviewed to examine whether or not they had SB and overnight polysomnography was performed at the sleep center. Various clinical variables were collected through medical record review. Results: The 331 PD patients were divided into 16 SB group (48.5%) and 17 NSB group (51.5%). SB patients were younger (p<0.02), had higher sleep efficiency (p<0.05), and showed shortened sleep latency (p<0.02) as compared with NSB patients. However, no difference was found between SB and NSB with respect to gender, duration or stage of PD, antiparkinsonian medications prescribed, and predominant motor symptoms. SB did not clearly relate to a specific sleep stage and other sleep variables except sleep efficiency and sleep latency. Although primary snoring was more prevalent in SB patients (p<0.05), other sleep disorders were seen with equal frequency in SB and NSB groups. Conclusion: Our results suggest that good sleep efficiency, shortened sleep latency, and age may have an effect on morning motor function (i.e., SB) in Parkinson's disease.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1111-1117
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• 1996

Structural deterioration of the bioprosthetic xenograft valves due to primary tissue failure occurs in two modes: from fatigue lesions with tear and wear with or without calcification and from calcification with obstruction. Two groups of consecutive 56 patients with the Hancock porcine ortic valve(HM) and of 1 13 patients with the standard-profile onescu-Shiley bovine pericardial valve(ISM) explanted from mitral position at the time of re-replacement surgery for primary tissue failure at Seoul national University Hospital until 1994, were studied for clinical and pathological features. Their ages at primary implant were 31.9 $\pm$9.2 years In HM and 30.4$\pm$ 12.5 years in ISM. Hemodrnamic dysfunction of the failed mitral bloprostheses were predominantly insufficiency in HM(64.3%) and stenosis in ISM(51.3%)(p<0.001). Pathologic findings of the explanted mitral valves reflected these hemodynamic changes, revealing failure more often from tissue damage(tears and wears) in HM and more often from calcification in ISM(p< 0.001). Explant period(from primary implant to explant) was relatively short in ISM(8.7$\pm$2.6years), compared with the one in HM(10.4 $\pm$2.6 years)(p<0.001). In conclusion, both the Hancock and the lonescu-shiley valves would fail from calcification as well as issue damage. However, while the Hancock porcine valves in mitral position failed more frequently from tissue failure and insufficiency, the standard-profile lonescu-Shiley pericardial valves did from calcification and stenosis, especially in young pAtients . Although the possibility of less occurrence of valve failure from mechanical reasons may be expected with newer generation bloprostheses, it does not seem to Improve durability significantly unless further refinement in antimineralization is achieved. Therefore, clinical use of the glutaraldehyde-treated bioprosthetic valves is, at present, limited to the patients of advanced age groups.