• Korea-Australia Rheology Journal
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• v.20 no.2
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• pp.89-94
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• 2008

To satisfy good mechanical and optical properties of polymer-coated film products, it will be indispensable to elucidate the molecular orientation of polymer chains within coating liquids in coating flows. Using hybridized numerical method between computational fluid dynamics (CFD) and Brownian dynamics (BD) simulations can provide the useful information for the better quality control of coated films. Flexible polymer chains, e.g., ${\lambda}$-DNA molecules here, change their conformation according to the flow strength and the flow type. The molecular conformation within the coated film on the web or substrate is quite different, because the polymer chains experience the complicated flow strength and flow types in flow field. Especially in the slot coating flow, these chains are more extended by the extension-like flow field generated in the free surface curvature just beyond the downstream die region. Also, the polymer chain extension beneath the free surface can be affected by the die geometry, e.g., the coating gap, changing flow field.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.69.1-69
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• 2003

RSH (relA/spoT homolog) has been known to determine the level of guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp), which are the effector nucleotide of the prokaryotic stringent response and also play a role in antibiotic production and differentiation in Streptomyces species but not a little in eukaryotic organism, especially in plant. Salicylic acid (SA), a critical signal molecule of establishing systemic acquired resistance (SAR), could induce SAR in Pepper (Capcicum annuum) against Phytophthora capsici. And the extent of SAR induction was in proportion to the dosage of SA (or BTH). Suppression subtractive hybridization (SSH), a PCR-based method for cDNA subtraction, was carried out between SA-treated and non-SA-treated pepper leaves to isolate genes which may be responsible for defense signaling against pathogens. Early upregulated gene was selected from reverse northern and kinetics of SSH-genes transcripts in SA-treated pepper leaves upon SA treatment. Full-length cDNA of the gene (PepRSH； Pepper RelA / SpoT homolog) had an open reading frame (ORF) of 2166 bp encoding a protein of 722 amino acids and a significant homology with (p)ppGpp phosphohydrolase or synthetase. Genomic DNA gel blot analysis showed that pepper genome has at least single copy of PepRSH. PepRSH transcripts was very low in untreated pepper leaves but strongly induced by SA and methyljasmonic acid (MeJA), indicating that PepRSH may share common SA and MeJA-mediated signal transduction pathway Functional analysis in E. coli showed PepRSH confers phenotypes associated with (p)ppGpp synthesis through a complementation using active site mutagenesis.

• YAKHAK HOEJI
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• v.54 no.6
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• pp.500-506
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• 2010

TNF-${\alpha}$ and VCAM-1 play a pivotal role in the pathogenesis of rheumatoid arthritis, and the development of drugs targeting these molecules has extended the therapeutical approaches to rheumatoid arthritis patients. Bispecific antibodies combine the antigen-binding sites of two antibodies within a single molecule and thus they are able to bind to two different epitopes simultaneously. A specific bispecific antibody format termed "Di-diabody" was made for the efficient approach to anti-inflammation. In this study, the DNA vector construct of Di-diabody was built up against two antigens, VCAM-1 and TNF-${\alpha}$. For evaluating this Di-diabody as a bispecific antibody on the efficacy of anti-inflammation, the proteins were analyzed according to each antigen binding affinity and cell based assay related separate molecules. The 7H/Humira Di-diabody produced in this study interacted with its ligands, VCAM-1 and TNF-${\alpha}$, respectively. Also, this antibody exhibited the similar functional activities as compared to 7H-IgG in respect to inhibition of hVCAM-1-induced cell adhesion and Humira-IgG in respect to inhibition of TNF-${\alpha}$ induced cytotoxicity. Further study to elucidate the pharmacological significance of the Di-diabody is warranted using experimental animals.

• Journal of Microbiology
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• v.35 no.4
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• pp.327-333
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• 1997

Although extensively characterized in human cells, no heterogeneous nuclear ribonucleoprotein(hnRNP) has been found in the fission yeast Schizosaccharomyces pombe which is amenable to genetic studies and more similar to mammals than Saccharomyces cerevisiae is in terms of RNA processing. As a first step to characterize hnRNPs from S. pombe, attempt was made to find human hnRNP A1 homologs from S. pombe. The RNA molecule (A1 winner) containing the consensus high-affinity hnRNP A1 binding site (UAGGGA/U) was synthesized in vitro and used in an ultraviolet(UV) light-induced protein-RNA cross-linking assay. A number of S, pombe proteins bound to the A1 winner RNA. An approximately 50-kDa protein(p50) cross-linked more efficiently to the A1 winner RNA than other proteins. The p50 protein did not cross-link to a nonspecific RNA, but rather to the A1-5’ SS RNA in which the consensus 5’ splice junction sites of S. pombe introns were abolished. This suggests that the p50 protein, however, did not bind to the single-stranded DNA to shich the human hnRNP A1 could bind and be eluted with 0.5M NaCl. Further analysis should reveal more features of this RNA-binding protein.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.393-398
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• 2015

Aptamers are composed of single-stranded oilgonucleotides that can selectively bind desired molecules. It has been reported that RNA or DNA could act as not only a genetic messenger but also a catalyst in metabolic pathways. RNA aptamers (average sizes 40-50 bp) are smaller than antibodies and have strong binding capacities to target molecules, similar to antigenantibody interactions. Once an aptamer was selected, it can be readily produced in large quantities at low cost. The objectives of this study are to screen and develop aptamers specific to oral pathogens such as Porphyromonas gingivalis, Treponema denticola, and Streptococcus mutans. The bacterial cell pellet was fixed with formaldehyde as a target molecule for the screening of aptamers. The SELEX method was used for the screening of aptamers and a modified western blot analysis was used to verify their specificities. Through SELEX, 40 kinds of aptamers were selected and the specificity of the aptamers to the bacterial cells was confirmed by modified western blot analysis. Through the SELEX method, 40 aptamers that specifically bind to oral pathogens were screened and isolated. The aptamers showed possibility as effective candidates for the detection agents of oral infections.

• Korean Journal of Environmental Biology
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• v.30 no.2
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• pp.77-89
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• 2012

With the advent of the genomics era powered by DNA sequencing technologies, life science is being transformed significantly and biological research and development have been accelerated. Environmental biology concerns the relationships among living organisms and their natural environment, which constitute the global biogeochemical cycle. As sustainability of the ecosystems depends on biodiversity, examining the structure and dynamics of the biotic constituents and fully grasping their genetic and metabolic capabilities are pivotal. The high-speed high-throughput next-generation sequencing can be applied to barcoding organisms either thriving or endangered and to decoding the whole genome information. Furthermore, diversity and the full gene complement of a microbial community can be elucidated and monitored through metagenomic approaches. With regard to human welfare, microbiomes of various human habitats such as gut, skin, mouth, stomach, and vagina, have been and are being scrutinized. To keep pace with the rapid increase of the sequencing capacity, various bioinformatic algorithms and software tools that even utilize supercomputers and cloud computing are being developed for processing and storage of massive data sets. Environmental genomics will be the major force in understanding the structure and function of ecosystems in nature as well as preserving, remediating, and bioprospecting them.

• Journal of Life Science
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• v.13 no.6
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• pp.856-864
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• 2003

The 16S rRNA gene is the most common gene in the phylogenetic analysis of procaryotes. However very high conservative of 16S rRNA has limitation in the discrimination of highly related organisms, hence other molecule was applied in this study and the result was compared with that of 16S rRNA. Three COGs (Clusters of Orthologous of protein) were only detected in 42 procaryotes ; transcription elongation facto. (COG0195), bacterial DNA primase (COG0358) and uridylate kinase (COG0528). Uridylate kinase gene was selected because of the similarity and one single copy number in each genome. Bacteria, belong to same genus, and Archaebacteria were same position with high bootstrap value in phylogenetic tree like the tree of 16S rRNA. However, alpha and epsilon Proteobcteria showed different position and Spirochaetales of Eubarteria was grouped together with Archaebacteria unlike the result of 16S rRNA. Uridylate kinase may compensate the problem of very high conservative of 16S rRNA gene and it would help to access more accurate discrimination and phylogenetic analysis of bacteria.

• Korean Journal of Animal Reproduction
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• v.24 no.2
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• pp.125-142
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• 2000

13). Analysis of a purified preparation of eCG revealed that its $\beta$ -subunit consists of 149 amino acids, which was confirmed by the molecular cloning of its cDNA. There seem to be at least four to six, or even as many as 11, O-glycosylation sites on the extended C-tenninal region of the eCG $\beta$-subunit. Interestingly, eCG is a unique member of this family, as it appear to be a single molecule that possesses both LH- and FSH-like activities. Using the cDNA prepared from mRNA extracted from equine placental and pituitary tissues, we cloned the cDNA of eCG $\alpha$- and $\beta$ -subunits and eFSH $\beta$ -subunit. The mRNA expression of each subunit seems to be independently regulated, which may account for differences in the quantities of $\alpha$ - and $\beta$ -subunits in the placenta and pituitary. Thus, eCG is a distinct molecule from the view points of its biological function and glycoresidue structures. Recombinant eCGs including the mutants which lack oligosaccharides will be useful tools for analyzing the structure-function relationships of gonadotropins in the horse as well as other species. Similar experiments will also clarify the proposed structure and biological functions for the glycoprotein hormones. These experimental are now possible, and hopefully a resolution of the existing controversy will be forthcoming in the near future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.1053-1062
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• 2011

Reactive oxygen species (ROS), including singlet oxygen (${O_2}^1$), superoxide anion radical ($O_2{\cdot}^-$), hydroxyl radical ($HO{\cdot}$), peroxyl radical ($ROO{\cdot}$), hydrogen peroxide ($H_2O_2$), and hypochlorous (HOCl), are generated as byproducts of normal cellular metabolism. ROS induce damage to many biological molecules, such as lipids, proteins, carbohydrates, and DNA. It is widely believed that some degenerative diseases caused by ROS can be prevented by the high intake of fruits and vegetables due to their antioxidant activities. Recently, research on natural antioxidants has become increasingly active in various fields. Several assays have been developed to measure the total antioxidant capacity of antioxidants in fruits and vegetables in vitro. These assays include those for DPPH radical scavenging activity, SOD-like activity, total polyphenol content, oxygen radical absorbance capacity, reducing power, trolox equivalent antioxidant capacity (ABTS assay), single-cell gel electrophoresis (comet assay), and a cellular antioxidant activity assay. Because different antioxidant compounds may act through different mechanisms in vitro, no single assay can fully evaluate the total antioxidant capacity of foods. Due to the complexity of the composition of foods, it is important to be able to measure antioxidant activity using biologically relevant assays. In this review, recently used assays were selected for extended discussion, including a comparison of the advantages and disadvantages of each assay and their application to fruits and vegetables.