• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.4
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• pp.325-331
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• 2007

In this study, the inter-metal dielectric material of FSG was changed by low-k material in $0.13{\mu}m$ foundry-compatible technology (FCT) device process based on fluorinated silicate glass (FSG). Black diamond (BD) was used as a low-k material with a dielectric constant of 2.95 for optimization and yield-improvement of the low-k based device process. For yield-improvement in low-k based device process, some problems such as photoresist (PR) poisoning, damage of low-k in etch/ash/cleaning process, and chemical mechanical planarization (CMP) delamination must be solved. The PR poisoning was not observed in BD based device. The pressure in CMP process decreased to 2.8 psi to remove the CMP delamination for Cu-CMP and USG-CMP. $H_2O$ ashing process was selected instead of $O_2$ ashing process due to the lowest condition of low-k damage. NE14 cleaning after ashing process lot the removal of organic residues in vias and trenches was employed for wet process instead of dilute HF (DHF) process. The similar-state of SRAM yield was obtained in Cu/low-k process compared with the conventional $0.13{\mu}m$ FCT device by the optimization of these process conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1292-1295
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• 2004

본 연구는 Cu CMP공정 중 알루미나 연마입자의 wafer 표면에서의 점착과 오염을 AFM (Atomic Force Microscopy)을 사용하여 슬러리내에서 점착력 측정과 실제 연마 후 wafer 표면의 오염을 실험적으로 비교 평가하였다. 연마입자의 adhesionn force 측정에 있어서도 역시 wafer들의 zetapotential 결과와 잘 일치하였으며, 모든 wafer 종류에 관계없이, 산성 영역에서 염기성영역의 슬러리가 적용됨에 따라 adhesion force가 작아짐을 확인할 수 있었다. 특히 FSG wafer의 zetapotential 결과는 비록 산성 분위기에서는 양성 전하값을 나타내었으나, 염기성 분위기의 pH에서는 급격하게 음성 전하값을 나타내었고, 이는 adhesionn force결과와 FESEM 결과와 잘 일치하였다.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.178-184
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• 2007

Purpose : Since the first report by Mendoza in 1990, there have been several studies reporting that long-term intravenous methylprednisolone(MP) pulse therapy combined with cyclosporin A(CsA) or cyclophosphamide might be beneficial for the treatment of steroid resistant focal segmental glometulosclerosis(FSGS). We investigated the therapeutic effect of long-term MP pulse therapy without CsA or cyclophosphamide on steroid resistant FSGS. Methods : The medical records of the 10 steroid resistant FSGS patients who were treated with MP pulse therapy by the Mendoza protocol without CsA or cyclophosphamide in our hospital were retrospectively reviewed. Results : The median age at onset was 2.6 years(range 1.1-10.6 years) and the median age at the initiation of therapy was 5.7 years(range 1.8-20 years). The median duration of follow-up was 35 months(range 4-132 months). At the end of therapy, 5 patients achieved complete remission(50%) and 2 partial remission(20%), one of whom relapsed after the therapy. Three patients did not respond to the therapy, two of whom progressed to end-stage renal failure during the therapy eventually requiring kidney transplantation. Conclusion : Intravenous long-term MP pulse therapy without CsA or cyclophosphamide by the Mendoza protocol may be effective in a subset of patients with steroid-resistant FSGS.

• Journal of the Korea Computer Industry Society
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• v.2 no.12
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• pp.1557-1562
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• 2001

The echo response time has been a concern in the performance of the UNIX systems, a significant tail always appears in the distribution of echo response time, though the average echo response time is less serious. This paper addresses the issue of echo response times in the UNIX systems. We explain how the Fair Share Scheduler (FSS) works and explain why the FSS might cause excessive echo response times and show by analysis how echo response time reacts to key parameters under FSS. Finally, we present a recommended solution that should improve the echo response time drastically. This solution is a refined FSS which will overcome the echo response time problem while retaining the essence of the FSG. This will enhance the UNIX performance and productivity.

• Applied Biological Chemistry
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• v.34 no.3
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• pp.265-272
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• 1991

In order to utilize fish skin effectively, the acid-soluble collagen was extracted from the skin of filefish, Novoden modestrus, and the filefish skin collagen(FSG) was modified by papain-catalyzed incorporation of L-leucine alkyl ester(Leu-OCn). The functional properties of an enzymatically modified collagen were measured. The $FSC-Leu-OC_8$ showed very good emulsifiability and foamability and was suitable for use as a low-fat content proteinaceous surfactant.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.17-24
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• 2000

Purpose: MCNS is found in approximately $85\%$ of the idiopathic nephrotic syndrome in children and shows good prognosis with initial steroid therapy. However in FSGS, there is poor prognosis with initial therapy and shows higher rate of progression to chronic renal failure and relapse after kindney transplantation. We have experienced 8 patients who were diagnosed as MCNS on initial renal biopsy and then progressed to FSGS on follow-up biopsy. So we have investigated their clinical course and risk factors for transition of MCNS to FSGS. Methods: We conducted a retrospective study with a review of histopathologic findings and clinical manifestations of 296 cases of MCNS and FSGS that were diagnosed from January 1988 to May 1999. We classified them into 3 groups according to the histopathologic finding; MCNS, FSGS, MCNS progressed to FSGS in follow-up biopsy. Results: The number of children was 296 cases comprising 241 cases($81.4\%$) showing MCNS, 8 cases($2.7\%$) transition group, 47 cases($15.9\%$) FSGS. The mean onset age was $6.0{\pm}2.6$years in MCNS, transition group $8.3{\pm}2.3$years, FSGS $7.2{\pm4.3$years, and the gender (M:F) ratio was 3.7:1 in MCNS, 3:1 in transition group, 1.8:1 in FSGS. Comparing the presence of initial hematuria, hypertension,24 hour urine protein, serum albumin, serum creatinine, there were significant difference between the transition group and the FSGS group in the following points; 24hour urine protein $684:342mg/m^2/hr$(P<0.05), serum albumin 1.92: 2.47g/dL(P<0.05), serum cholesterol 494:343mg/dL(P<0.05). Refractoriness to steroid therapy was 13.3$\%$ in MCNS. $12.5\%$ in transition group, $29.6\%$ in FSGS; significantly higher in FSGS(P<0.05). Immunosuppressant therapy was performed in $58.5\%$ of MCNS, $100\%$ in transition group, $80.8\%$ in FSGS; transition group showed significantly higher .ate(P<0.05) comparing with MCNS. Mean number of relapse and duration from onset to first relapse showed no significance difference between these groups. Conclusion: 249 patients with MCNS have been followed and $3.2\%$ (8 patients) of them has shown change in pathologic diagnosis from MCNS to FSCS. The risk factor for transition could not be found. Our results point to the need for a follow-up biopsy to certify the possibility of transition to FSCS in some MCNS cases with refractory cases to steroid therepy, frequent relapsing cases, or in case of no remission in spite of vigorous immunosuppressant therapy.

• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1219-1224
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• 2005

Purpose : The prevalence of obesity in children and adolescents has been rising rapidly in Korea because of changes of diet and lifestyle. As with adults, obesity in children and adolescents can cause diabetes mellitus, hyperlipidemia, cardiovascular diseases and renal diseases. The aim of the present study is to examine the relation of obesity, glomerular filtration rate(GFR) and serum cystatin C concentration in children and adolescents. Methods : Data of 115 children and adolescents aged between 6 years and 20 years without clinical evidence of renal diseases were included in the study. From May 2004 to December 2004, blood samples were collected from children and adolescents who were seen at the Department of Pediatrics at Chungang University Yongsan Hospital. Obesity degrees and body mass indices(BMI) were measured, and GFRs were estimated from Schwartz's formula. Serum cystatin C was measured by particle enhanced nephelometric immunoassay using Behring Nephelometer II. Results : GFRs were significantly different between the obese group(BMI >95 percentile, $145.79{\pm}23.10mL/min$) and the non-obese group(BMI <95 percentile, $134.61{\pm}26.19mL/min$) divided by BMI (P=0.031). GFRs were not significantly different between the obese group(obesity degree >120 percent, $144.29{\pm}23.08mL/min$) and the non-obese group(obesity degree <120 percent, $134.54{\pm}26.57mL/min$) divided by obesity degree(P=0.051), but were significantly different between severe obese group (obesity degree >150 percent, $155.55{\pm}20.40mL/min$) and the non-obese group(P=0.004). GFRs were correlated positively with BMI($r^2=0.037$, P=0.039), but were not correlated significantly with obesity degree($r^2=0.030$, P=0.066). Serum cystatin C concentrations were not significantly different between the obese group and the non-obese group, divided by BMI as well as by obesity degree(P>0.05). Conclusion : Obesity may lead to an alteration of renal hemodynamics such as hyperfiltration, appropriate control and management for obesity is necessary.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.1-10
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• 1999

Purpose: Up to date there is no nationwide survey on epidemiological or clinical data of nephrotic syndrome, so we investigated about age of onset, sex, result of renal biopsy, treatment method, its results of treatment, its responsiveness, time of response to treatment and pattern of relapse in Korea. Methods: Between 1987 and 1997, 2193 patients with primary nephrotic syndrome diagnosed at 38 university hospital and general hospital in Korea were included. Of these 1655 were male and 538 were female. Incidence peaked at 1-5 years of age. Results: Results were as follows; 1) Among 2193 cases, male was 1655($75.5\%$), female was 538 cases($24.5\%$) and male to female ratio was about 3:1. Among 1752 patients with MCNS, male was 1338, female was 414 and male to female ratio was about 3.23:1. The most prevalent age group was 1-5 years of age. 2) Renal biopsy was done in 942 cases($43\%$), pathologic findings were as follows; MCNS 646 cases($68.6\%$), FSCS 149 cases($15.8\%$). 3) Regimen of treatment were as follows; prednisolone 1191 cases, Calcort 192 cases, cyclophosphamide 251 cases, cyclosporin A 223 cases, MPD pulse therapy 120 cases.4) Complete response to treatment were noted in 1597 cases($82.2\%$, n=1944). 5) Responsiveness according to result of renal biopsy were significantly different between MCNS and FSGS. Complete response were noted in $86.5\%$ among patients with MCNS, $35.8\%$ in patients with FSGS. 6) Time of response to treatment were noted between 1 and 4 weeks after treatment in 879 cases($67.4\%$, n=1305). 7) 994 cases($73.1\%$) relapsed during follow up, most frequently between 2 months and 6 months after response. Conclusion : Nationwide survey of epidemiological and clinical data were performed in childhood primary nephrotic syndrome. Most of the clinical and epidemiological data were similar to other reports from U.S.A. and from Europe, however male to female ratio is higher in Korean nephrotic syndrome(3:1 in contrast to 2:1).

• 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.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.11-19
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• 1999

Purpose: MCNS is found in approximately $85\%$ of the idiopathic nephrotic syndrome in children and shows good prognosis with initial steroid therapy. MCNS most commonly appears between the ages of 2 and 10 yr. But the incidence and prognosis in adolescent MCNS are different from those found in young children; the prognosis and the response to therapy is unfavorable with increasing ages. So we compared the prevalence and the clinical manifestations of adolescent MCNS with that of childhood MCNS for management of adolescent MCNS. Methods: We conducted a retrospective study with a review of histopathologic findings and clinical manifestations of the 216 cases with MCNS which were divided into children group and adolescent group by their age of onset; under 12 years(childhood) and between 12-18 years(adolescent). Results: 1) The number of childhood idiopathic nephrotic syndrome was 245 cases, and that of adolescent idiopathic nephrotic syndrome was 55 cases. 188 cases($77\%$) showed MCNS, 30 cases($12\%$) FSGS, 4 cases($1.6\%$) MSPCN in childhood idiopathic nephrotic syndrome; 28 cases($51\%$) showed MCNS, 12 cases($22\%$) FSGS in adolescent idiopathic nephrotic syndrome. 2) The mean onset age was $7.53{\pm}5.5$ years, and the male to female ratio was 3.8:1 in childhood onset and 2.5:1 in adolescent onset with male predominance. 3) Hematuria was associated with $17\%$ of childhood onset and $39.3\%$ of adolescent onset disease(P=0.005). Hypertension appeared in $0.5\%\;and\;7\%$ in each group without significant difference between the groups. 4) 24 hour urine protein, SPI, albumin, BUN, cholesterol level showed no significant difference. 5) The response of childhood onset and adolescent onset MCNS to steroid therapy showed complete remission in $11.7\%\;&\;14.7\%$, infrequent relapsing in $29.2\%\;&\;28.5\%$, frequent relapsing in $23.9\%\;&\;14.7\%$, steroid dependent in $21.8\%\;&\;28.6\%$ each. Steroid resistant showed $13.3\%\;&\;14.7\%$ with no significance. 6) Immunosuppresant therapy was performed $57\%$ in childhood onset and $65\%$ in adolescent onset. 7) Mean number of relapse and duration from onset to first relapse showed no significance between two groups. Conclusion : Our results indicate that the incidence of hematuria, the rate of steroid dependent and frequent relapsing, and the recurrence rate were higher in adolescent MCNS; showed poorer steroid responsiveness and prognosis. Our data also point to the need for a more aggressive therapy to treat and make recommendations for the adolescent population as a whole.