• Journal of Chest Surgery
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• v.32 no.4
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• pp.341-346
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• 1999

Background: Thirty children ranging from 3 to 15 years of age underwent cardiac valve replacement at Dongsan Medical Center from 1982 to 1997. Material and Method: There were 16 boys and 14 girls. The mean age was 12.1. The underlying pathological cause for valve replacement was congenital heart disease in 17 children and acquired heart disease in 13. The valve replaced was mitral in 15 children, aortic in 11, tricuspid in 3, and combined aortic and mitral in 1. Twenty-one mechanical and 10 tissue valves were placed: primary mechanical valve have been utilized since 1985. Eight of ten patients with tissue valves have had successful second valve replacements 4 to 11 years after the initial operation. Result: The operative mortality was 6.7%, but mortality was higher among patients less than 5 years of age and patients who had previous cardiac operations. Of the 28 operative survivors, 4 patients were lost to follow-up: the remaining patients were observed for a total of 2091 patient/months(mean 74.7 months, maximum 187 months). There was one late death from dilated cardiomyopathy after mitral valve replacement in 7 year-old patient with atrioventricular septal defect. After the operation, all patients with mechanical valves were placed on a strict anticoagulant regimen with Coumadin. The actuarial survival rate was 96% at the end of the follow-up. No instance of thromboembolism or major bleeding were observed in the survivors. Conclusion: These results indicate that valve replacement can be performed with low mortality in children, and with satisfactory long-term survival.

• Resources Recycling
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• v.13 no.6
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• pp.31-36
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• 2004

This experiment was carried out to examine the effects of morphology on properties of La-Co substituted SrM ferrite. The magnetic properties of calcined and sintered materials were varried with the substitutional amount of La and Co elements in Sr-ferrite. In the substituted SrM ferrite, the atomic fraction x of La is directly related to the mole ratio n of iron oxide and the atomic fraction y of Co by equation x=2ny. The Hcj values of the calcined powder were about 270 kA/m and 240 kA/m with x=0.3 and x=0.2, respectively at stoichiometry, n=6.0. Crystallites of the sintered material were grown with a plate shape, and their size decreased with increasing mole ratios. Such a shape was caused by the initial state of crystallite formed after calcination. In case of x=0.3 and n=6.0, Br was 415 mT and Hcj was 355 kA/m, and in x=0.2 and n=6.0, Br was 410 mT and Hcj was 370 kA/m. The squareness in 2nd quarter of BH curve with x=0.2 was smoothly improved to compared with x=0.3.

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.84-91
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• 2007

Purpose: The aim of this study was to report seven cases of metallic radial head prosthesis and present the limit of use in Korea. Materials and Methods: Metallic radial head arthroplasty was performed on 7 patients between April 2006 and December 2006, who had complex elbow injury including comminuted radial head fracture. Indication, operative findings and outcome were assessed. Availability and payment of implant were investigated. Results: All of the patients had more than one associated injury including coronoid fracture, olecranoan fracture, and ligament ruptures. According to Mason classification, there were three type III and four type IV fractures. All radial head fractures were too comminuted to reconstruct. There were two excellent results, four good, and one poor, as graded by Mayo score. There were no patient with instability and implant related complications. Insufficient supply of implant did not enable to do scheduled surgery in 2 cases. Current medical insurance did not cover charge for radial prosthesis, five patients could not help paying for that by themselves. Conclusion: Metallic radial head implants are useful when the radial head cannot be repaired reliably. Preoperative preparing and coverage by medical insurance based on appropriate indication are helpful for decision for a treatment option.

• Journal of Life Science
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• v.6 no.4
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• pp.304-312
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• 1996

In the present report, a p[ossibility of the interaction fo Ser-33 and Asp-112 residues in folding of tryptophan synthase $\alpha$ subunit was explored by examining the effect of single or double substitution of these residues on folding of $\alpha$ subunit in E. coli. $\alpha$ subunit of which Ser-33 was substituted with Leu (SL33) was accumulated as insoluble aggregate form, when overproduced in E. coli, whereas $\alpha$ subunit of which Asp-112 was replaced by Asn (DN112) or Gly (DG112) was accumulated as soluble form to the similar extent as wild type $\alpha$ subunit was. When these alterations were combined into one protein, the synergistic effect of residues 33 and 112 on the amount of aggregate form was shown. The amount of doubly altered SL33/DG112 $\alpha$ subunit as aggregate form was increased 5-13 fold that of SL33 $\alpha$ subunit, and the amount of SL33/DG112 $\alpha$ subunit as aggregate form was decreased 3-4 fold that of SL33 $\alpha$ subunit. Aggregates are derived from the specific association of partially folded or unassembled subunits in the folding process. Therefore, this result suggests that residues 33 and 112 of $\alpha$ subunit may unteract during the folding of this enzyme in E. coli.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2004.12a
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• pp.27-34
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• 2004

This experiment was carried out to examine the effects of morphology on properties of La-Co substituted SrM ferrite. The magnetic properties of calcined and sintered materials varied with the substitutional amount of La and Co elements in Sr-ferrite. In the substituted SrM ferrite, the atomic fraction x of La is directly related to the mole ratio n of iron oxide and the atomic fraction y of Co by equation x=2ny. The HcJ values of the calcined powder were about 270 kA/m and 240 kA/m with x=0.3 and K=0.2, respectively at stoichiometriy, n=6.0. Crystallites of the sintered material were grown with a plate shape, and their size decreased with increasing mole ratios. Such a shape was caused by the initial state of crystallite formed after calcination. In case of x=0.3 and n=6.0, Br was 415 mT and HcJ was 355 kA/m, and in x=0.2 and n=6.0, Br was 410 mT and HcJ was 370kA/m. The squareness in 2nd quarter of BH curve with x=0.2 was smoothly improved compared with x=0.3

• Applied Biological Chemistry
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• v.43 no.2
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• pp.95-99
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• 2000

A series of hetero ring (X) substitued chalcone derivatives with farnesyl protein transferase (FPTase) inhibition activities $(pI_{50})$ values determined in vitro is analyzed by modified Free-Wilson (F-W) and Hansch method for quantitative structure activity relationship (QSARs). On the basis of F-W analysis on the FPTase inhibitory activity of a training set of the compounds, none of the (X)-substituents were not contribute the activity. But the net charge of ${\alpha}$ carbon atom is contribute the activity than that of ${\beta}$ carbon atom. And the relative orders of the (Y)-substituents on the activity are ortho>meta>para-substituents. According to Hansch approach, the activities would depend largely on the optimal, $(R_{opt.}=-0.35)$ resonance effect with ortho substituted $(I_o>0)$ electron donating group (R<0) and STERIMOL parameter, $B_1$ constant. The inhibition activity between hetro ring substituents have been a proportioned with each others and none substituent(H), 45 showed the highest FPTase inhibition $(pI_{50}=4.30)$ activity.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.299-300
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• 2003

본 연구자들은 이산화탄소($CO_2$)에 의한 셀룰로오스 카보네이트의 제조 및 재생 셀룰로오스 섬유 제조에 대한 몇몇 기초 연구성과를 발표한 바 있다[1, 2]. 이번 연구에서는 이산화탄소와의 반응을 통해 제조된 셀룰로오스 카보네이트 유도체의 치환도 변화에 따른 용해성을 평가하고 상그림표를 작성하였다. (중략)

• Journal for History of Mathematics
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• v.18 no.2
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• pp.117-126
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• 2005

In this paper, we analyze the basic concepts of permutation polynomials over finite fields, and the historical background through the use of the major classes of permutation polynomials over the fields. And also, we find a method of the polynomial representation with respect to cycles on the fields.

• Journal of the Korean GEO-environmental Society
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• v.4 no.4
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• pp.61-71
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• 2003

On the soft soil consisted of silty clay, the compulsion replacement method is useful for revetment and its safety is very much affected by compulsion replacement depth. Usual method calculating the compulsion replacement depth on silty clay is considered the bearing capacity of soft soil with undrained shear strength increase from ground surface and weight of revetment. But according to soil deposit, there are some cases of soft soil with inter sand layer or clayed silt, which affect the compulsion replacement depth. In this paper, the compulsion replacement depth on soft soil with inter sand layer is analyzed by layered weighted average bearing capacity considering influence effect of Perloff et al.(1967) and compared with numerical method(FLAC). In the result, the calculated depth from numerical method is nearest to layered weighted average bearing capacity in case that contact width under revetment is $0.2B_o$(soft soil with inter sand layer), $0.5B_o$(only soft soil) and the effect of contact width under revetment is less than undrained shear strength, thickness and location of inter sand layer. Also the compulsion replacement depth is as much as the inter sand thickness($d_2/B_o$) is thinner, the inter sand layer location($d_1/B_o$) is farther, and undrained shear strength is less.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.129-136
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• 2010

This study is to investigate experimentally the engineering characteristics of cement mortar according to the replacement method and contents of recycled aggregate powder (RP) by collecting the recycled aggregate powder with the maximum size of below 0.08 mm and 0.15 mm. then, the results of the study can be summarized as follows. The flow of flesh mortar represented a trend in decreasing while the recycled aggregate powder was substituted as it is compared with that of plain. In addition, in case of correlation between tests, it appeared that the correlation between flow and ring flow is big. In the case of the characteristics of hardened mortar, the strength showed more improvements as the RP was substituted to aggregate than the case, which is substituted to aggregate. In addition, it was verified that the results in which the RP was substituted to aggregate by 5% represented similar values to that of the plain according to the passage of age.