• Macromolecular Research
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• v.15 no.6
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• pp.581-586
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• 2007

Cast DNA/polyethyleneimine (PEI) blend membranes containing different amounts of DNA were prepared using acid-base interaction and characterized with the aim of understanding the polymer electrolyte membrane properties. Two different molecular weights of PEI were used to provide the mechanical strength, while DNA, a polyelectrolyte, was used for the proton transport channel. Proton conductivity was observed for the DNA/PEI membrane and reached approximately $3.0{\times}10^{-3}S/cm$ for a DNA loading of 16 wt% at $80^{\circ}C$. The proton transport phenomena of the DNA/PEI complexes were investigated in terms of the complexation energy using the density functional theory method. In the case of DNA/PEI, a cisoid-type complex was more favorable for both the formation of the complex and the dissociation of hydrogen from the phosphate. Since the main requirement for proton transport in the polymer matrix is to dissociate the hydrogen from its ionic sites, this suggests the significant role played by the basicity of the matrix.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.10a
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• pp.25-26
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• 2008

일반적인 분산염료, Phthalimide계 중간체로 사용한 분삼염료, Diester계 커플러만 이용한 분산염료와 비교한 Diester계 치환기를 이용한 분산 염료들은 R/C조건과 EtOAc와 증류수로 층분리하여 증류수층의 UV-Vis absorbance은 떨어지고 용해성은 증가한다. 그리고 Thiopene ring만 가진 염료와 비교한 염료들은 같은 파장에서의 UV-Vis absorbance은 떨어져 용해도는 증가하고 Thiopene ring과 Azo group의 분해에 의한 화합물 때문에 단파장에서의 UV-Vis absorbance가 크게 증가하여 염색 폐수의 색도를 감소시킬 수 있다.

• Genomics & Informatics
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• v.4 no.4
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• pp.182-187
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• 2006

6-Phosphogluconolactonase (6PGL) is one of the key enzymes in the ubiquitous pathways of central carbon metabolism, but bacterial 6PGL had been long known as a missing enzyme even after complete bacterial genome sequence information became available. Although recent experimental characterization suggests that there are two types of 6PGLs (DevB and YbhE), their phylogenetic distribution is severely biased. Here we present that proteins in COG group previously described as 3-oarboxymuconate cyclase (COG2706) are actually the YbhE-type 6PGLs, which are widely distributed in Proteobacteria and Fimicutes. This case exemplifies how erroneous functional description of a member in the reference database commonly used in transitive genome annotation cause systematic problem in the prediction of genes even with universal cellular functions.

• Journal of Korea Foundry Society
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• v.24 no.3
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• pp.153-158
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• 2004

본 연구에서는 기존 고압주조법의 해결과제인 고속충진 시 혼입되는 금형 cavity 내부의 유해 gas에 의한 gas porosity를 제어하기 위한 고속 사출 전 진공시스템 설계와 응고과정에서 발생되는 응고수축에 의한 shrinkage를 효과적으로 제어하기 위한 국부가압 스퀴즈의 조합시스템의 설계로 최적의 기계적 성질을 갖는 부품을 제조할 수 있는 공법을 개발하였다. 또한 개발된 신공법으로 자동차용 고내마모성 요구부품인 Reaction Shaft Support에 기존의 주철제를 대체하는 Al-15wt.%Si 과공정합금을 적용하여 시제품을 제조하였으며, 기존의 공법과 비교한 결과, 내부 porosity가 없는 미세하고 균일한 공정 및 초정 Si의 미세조직을 얻을 수 있었고, 기계적 특성평가에서도 매우 우수한 결과를 얻을 수 있었다.

• Proceedings of the Korean Nutrition Society Conference
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• 2002.11b
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• pp.1157-1168
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• 2002

Vitamin C is an essential nutrient involved in many functions. Humans are unable to synthesize vitamin C de novo, because they lack the last enzyme in the biosynthetic pathway. Previous Recommended Dietary Allowances (RDAs) for vitamin C were based on prevention of deficiency with a margin of safety. However preventing deficiency may not be equivalent to ideal nutrient intake. Recommendation should be based on vitamin function in relation to concentration. For this goal, data set of the relationship between wide-range of vitamin C dose and resulting concentrations in plasma and tissues and characterization of functional outcomes in relation to these concentrations should be acquired. This article reviews the current knowledge in these areas and suggest how this knowledge may contribute toward establishing dietary guideline for ideal vitamin C intake.

• Proceedings of the Korean Nutrition Society Conference
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• 2002.11a
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• pp.54-70
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• 2002

Vitamin C is an essential nutrient involved in many functions. Humans are unable to synthesize vitamin C do novo, because they lack the last enzyme in the biosynthetic pathway. Previous Recommended Dietary Allowances (RDAs) for vitamin C were based on prevention of deficiency with a margin of safety. However preventing deficiency may not be equivalent to ideal nutrient intake. Recommendation should be based on vitamin function in relation to concentration. For this goal, data set of the relationship between wide-range of vitamin C dose and resulting concentrations in plasma and tissues and characterization of functional outcomes in relation to these concentrations should be acquired. This article reviews the current knowledge in these areas and suggest how this knowledge may contribute toward establishing dietary guideline for ideal vitamin C intake.

• BMB Reports
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• v.43 no.3
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• pp.158-163
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• 2010

Calumenin is a multiple EF-hand $Ca^{2+}$-binding protein located in the endo/sarcoplasmic reticulum of mammalian hearts. Calumenin belongs to the CREC family of $Ca^{2+}$-binding proteins having multiple EF-hands. $Ca^{2+}$ homeostasis in the sarcoplasmic reticulum (SR) of mammalian hearts is maintained by RyR2, SERCA2 and other associated SR resident proteins. Evidence suggests that calumenin interacts with RyR2 and SERCA2, and therefore changes in the expression of calumenin could alter $Ca^{2+}$ cycling in mouse heart. In this review, current knowledge of the biochemical and functional roles of calumenin in mouse heart is described.

• Korean Chemical Engineering Research
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• v.55 no.4
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• pp.443-455
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• 2017

This article provides an exclusive overview of the synthesized aragonite precipitated calcium carbonate and its applications in various fields. The last decade has seen a steady increase in the number of publications describing the synthesis, characterization and applications of calcium carbonate morphologies. Mainly, two kinds of processes have been developed for the synthesis of aragonite precipitated calcium carbonate under controlled temperature, concentrations and aging, and the final product is single-phase needle-like aragonite precipitated calcium carbonate formed. This review is mainly focused on the history of developed methods for synthesizing aragonite PCC, crystal growth mechanisms and carbonation kinetics. Carbonation is an economic, simple and ecofriendly process. Aragonite PCC is a new kind of functional filler in the paper and plastic industries, nowadays; aragonite PCC synthesis is the most exciting and important industrial application due to numerous attractive properties. This paper describes the aragonite PCC synthetic approaches and discusses some properties and applications.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.177-181
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• 2009

Compositional gradient CrNx coatings were fabricated using arc ion plating in Ar/$N_2$ gaseous mixture by gradually increasing $N_2$ flux rate from 0 to 120 SCCM. The effect of negative substrate bias on the film microstructure and mechanical properties were systematically investigated with XRD, GDOES, and SEM. The results show that substrate bias has an important influence on film growth and microstructure of gradient CrNx coatings. The coatings mainly crystallized in the mixture of hexagonal $Cr_{2}N$ and fcc CrN phases. By increasing substrate bias, film microstructure evolved from an apparent columnar structure to an equiaxed one. With increasing substrate bias, deposition rate first increased, and then decreased. The maximum of deposition rate was 15 nm/min obtained at a bias of -50V.

• Proceedings of the Korean Society of Life Science Conference
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• 2006.09a
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• pp.80.1-80.1
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• 2006