• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.05a
• /
• pp.332-333
• /
• 2001

Genomic DNA was extracted from the blood of the freshwater crucian carp(Carassius carassius) from Kunsan in Korea, representing genetic similarity by polymerase chain reaction amplification of DNA as twelve of arbitrary primers. The electrophoretic analysis of polymerase chain reaction-random amplified polymorphic DNAs(PCR-RADP) products showed the high levels of similarity between different individuals in crucian carp.

• Journal of the Korean Applied Science and Technology
• /
• v.11 no.1
• /
• pp.53-60
• /
• 1994

The Synthesis of azobenzene containing long chain fatty acid and poly vinyl alcohol by esterification reaction($C_{n}-Azo-PVA$) was optimized, starting from P-(P'-hydroxy phenyl azo)-benzoic acid and the product of reaction containing azobenzene chromophores was investigated by ultraviolet spectrophotometery in toluene solvent at room temperature. In addition, UV absorption spectra of Langmmuir Blodggett (LB) film deposited on quartz plate have been measured and the structure of these compounds were ascertained by means of Ultraviolet and FT-IR. Recrystallization of reaction product in the solvent results the experimental yield obtained about 22.27% P-(P'-octadecyloxy phenyl azo)-benzoic acid-poly vinyl alcohol. Long chain azobenzene derivative-poly vinyl alcohols are induced phtoisomerization by u, v, and visible light irradiation. The LB film of azobenzene containing long chain fatty acids($C_{18}-Azo-PVA$) are possible of being applied to functional molecular devices such as photomemory and light switching.

• Journal of the Korean Chemical Society
• /
• v.51 no.3
• /
• pp.227-231
• /
• 2007

We improve Wilehemski-Fixmann theory for intrachain reaction dynamics of a polymer chain by taking into account excluded volume effects between reactive groups in the polymerchain. An approximate analytic expression for the intra-chain reaction dynamics is obtained for Gaussian chain model and compared to Brownian dynamics simulation results. The results of the present theory are in a better agreement to Brownian dynamics simulation results than those calculated by previously reported theories.

• Microbiology and Biotechnology Letters
• /
• v.22 no.6
• /
• pp.577-583
• /
• 1994

To classify Lactobacillus casei strains on the basis of difference in their chromosomal DNA sequence, we have performed polymerase chain reactions on their chromosomal DNA by using random primers, and followed by analyzing randomly amplified polymorphic DNA fragments. We also developed a mini-preparative method to isolate PCR-grade chromosomal DNA from Lacto- bacillus casei strains within 3 hours. Based on RAPD pattems by polymerase chain reactions with degenerated random primers, 4 Lactobacillus casei strains and 2 mutant strains were successfully discriminated. Results were very sensitive, strain-specific and reproducible. It was also reliable. These results suggest that RAPD may be applied efficiently for the identification of several Lactoba- cillus casei strains.

• Journal of Korean society of Dental Hygiene
• /
• v.15 no.6
• /
• pp.1063-1071
• /
• 2015

Objectives: The purpose of the study is to investigate the quantitative detection of periodontal pathogens before and after scaling by real-time polymerase chain reaction. Methods: Participants were voluntarily recruited at D university, and saliva samples were extracted before and after scaling. Multiple real-time polymerase chain reactions were used to analyze characteristics and the amount of nine kinds of periodontal pathogens; Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum, Parvimonas micra, Campylobacter rectus, and Eikenella corrodens. Results: After scaling, most periodontal pathogens except Eikenella corrodens were significantly decreased in all subjects(p<0.05). In addition, the percentage of microorganisms associated with disease, the microorganism risk index of periodontitis and the prevalence of red complex, orange complex, and Aggregatibacter actinomycetemcomitans was also significantly reduced after scaling(p<0.05). Conclusions: Scaling decreased in the amount of major periodontal pathogens and periodontitis prevalence rate.

• Polymer(Korea)
• /
• v.32 no.4
• /
• pp.385-389
• /
• 2008

Chain propagation and chain transfer in anionic polymerization of hexafluoropropylene oxide were investigated under various reaction conditions such as the stabilization of reaction temperature, the amount of hexafluoropropylene solvent, and the feeding rate of hexafluoropropylene oxide monomer. Anionic initiator for the polymerization was synthesized from cesium fluoride and hexafluoropropylene oxide in tetraethyleneglycol dimethylether. It was possible to obtain a high molecular weight poly(HFPO) ($M_w$ 14800) using the anionic initiator in conditions of stabilized reaction temperature, and optimized addition of solvent and monomer feeding (HFP/initiator mole ratio=31.5 and HFPO feeding rate=11.67 g/hr). Otherwise, chain transfer reaction in anionic polymerization was increased. From the results of molecular weight in various reaction conditions, it was found that chain propagation and chain transfer in anionic polymerization of HFPO were very sensitive to reaction conditions.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.6
• /
• pp.1365-1367
• /
• 2009

• Journal of Adhesion and Interface
• /
• v.3 no.2
• /
• pp.9-16
• /
• 2002

In the synthesis of water-based polyurethane using self-emulsification process, after being neutralized, polyurethane pre-polymers containing ionic pendant groups are dispersed by simple convective mixing. Preparation of dispersion is followed by chain extension reaction, which is considered as important step for growth of the molecular weight of polyurethane. In this work, pH variations in the aqueous phase were monitored during the chain extension process in the presence of water-soluble diamines. The optimum degree of chain extension and the average particle size in the polyurethane dispersions were examined with varying ionic pendent group contents, type of chain extenders, and feed rate of chain extenders, The initial pH value in the aqueous phase linearly increased and the optimum chain extension point could be obtained from the intersection of two linear lines having different slopes, All average particle sizes before chain extension reaction were almost same, however, the final average particle size increased as feed rates of chain extenders increased, In addition, as the ionic pendant group contents increased, the particle size decreased since the hydrophilicity and hydrodynamic volume increased. As carbon numbers of the chain extenders increased, the final particle size increased significantly. From the results, it was concluded that the chain extension reaction took place among the particles not only in a particle.

• Food Science and Biotechnology
• /
• v.14 no.1
• /
• pp.152-163
• /
• 2005

Lipid peroxidation is a primary cause of quality deterioration in meat and meat products. Free radical chain reaction is the mechanism of lipid peroxidation and reactive oxygen species (ROS) such as hydroxyl radical and hydroperoxyl radical are the major initiators of the chain reaction. Lipid peroxyl radical and alkoxyl radical formed from the initial reactions are also capable of abstracting a hydrogen atom from lipid molecules to initiate the chain reaction and propagating the chain reaction. Much attention has been paid to the role of iron as a primary catalyst of lipid peroxidation. Especially, heme proteins such as myoglobin and hemoglobin and "free" iron have been regarded as major catalysts for initiation, and iron-oxygen complexes (ferryl and perferryl radical) are even considered as initiators of lipid peroxidation in meat and meat products. Yet, which iron type and how iron is involved in lipid peroxidation in meat are still debatable. This review is focused on the potential roles of ROS and iron as primary initiators and a major catalyst, respectively, on the development of lipid peroxidation in meat and meat products. Effects of various other factors such as meat species, muscle type, fat content, oxygen availability, cooking, storage temperature, the presence of salt that affect lipid peroxidation in meat and meat products are also discussed.

• Korean Journal of Clinical Laboratory Science
• /
• v.38 no.3
• /
• pp.173-178
• /
• 2006

The production of extended-spectrum ${\beta}$-lactamases ($ESBL_S$) is the main mechanism of bacterial resistance to third-generation cephalosporins and monobactams, whose prevalence varies depending on the different geographical areas. In the last years it has increased notably to the point of being considered a health problem of great importance. The characterization of the ESBLs producing Klebsiella penumoniae strains present in clinical isolates is time-consuming. I describe here the development of a new system, which consists of a multiplex PCR. I found 51 K. pneumoniae strains to be presumptive strains ESBLs producers by clinical and laboratory standards institute (CLSI) guidelines. The double disc synergy test showed 47 positive K. pneumoniae, which were K. pneumoniae isolates. All ESBLs producing K. pneumoniae strains were resistant to antibiotic amikacin, gentamicin and ciprofloxacin. By multiplex PCR analysis, $bla_{TEM}$ gene in 17 strains 44 $bla_{SHV}$ genes and $bla_{CTX}$ genes in 33 strains were identified. In this study, the multiplex polymerase chain reaction (PCR) assay was a good method to detect and differentiate ESBLs producing K. penumoniae strains in clinical isolates.