• Archives of Pharmacal Research
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• 제20권2호
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• pp.115-121
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• 1997

Ile-269 in horse liver alcohol dehydrogenase isoenzyme S(HLADH-S) was mutated to serine by phosphorothioate-based site-directed mutagenesis in order to study the role of the residue in coenzyme binding. The specific activity of the mutant(1269S) enzyme to ethanol was increased 49-fold. All turnover numbers of 1269S enzyme toward 9 primary alcohols were increased. The mutant enzyme showed 3.6, 4.6, 11.6-fold higher catalytic efficiency for $5{\beta}$-androstane-3, 17-dione, $5{\beta}$-cholanic acid-3-one and retinal than wild-type, respectively. The reaction mechanism of 1269S enzyme was ordered bi bi as wild-type's. These results indicate that the hydrophobic interaction of Ile-269 residue with coenzyme plays an important role in dissociation of coenzyme from enzyme-coenzyme complex, which has been known as the rate limiting step of ADH reaction.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.105-106
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• 2017

Previous studies have confirmed the performance of pH reduction agents using liquid sodium phosphate based ammonium chloride as a pH reduction agent. In this study, the pH reduction performance considering economical and applicability as a practical stage and the property change analysis for the identification of the reaction mechanism of the pH reduction agent were carried out. As a result, the pH reduction performance at a low rate of the pH reducing agent was confirmed. The specific gravity of CaO decreased significantly after XRF analysis. It is also believed that this reduces the amount of Ca(OH)₂ produced and contributes to pH reduction.

• 한국세라믹학회지
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• 제52권5호
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• pp.356-360
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• 2015

The specific role of current collectors was investigated at the electrolyte/electrode interface of solid oxide fuel cells (SOFCs). Ag grids were fabricated as current collectors using electrohydrodynamic (EHD) jet printing for precise control of the grid geometry. The Ag grids reduced both the ohmic and polarization resistances as the pitch of the Ag grids decreased from $400{\mu}m$ to $100{\mu}m$. The effective electron distribution along the Ag grids improved the charge transport and transfer at the interface, extending the active reaction sites. Our results demonstrate the applicability of EHD jet printing to the fabrication of efficient current collectors for performance enhancement of SOFCs.

• Food Science and Biotechnology
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• 제15권3호
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• pp.385-391
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• 2006

In Korea, different kinds of genetically modified (GM) crops are under development, including GM-rice expressing insecticidal crystal (Cry) proteins of Bacillus thuringiensis (Bt) modified to change a single amino acid. In this study, amino acid (aa) sequences of modified Cry proteins were compared to that of known allergens, and Cry proteins expressed in GM-rice were identified by using Cry protein specific polyclonal antibody. The antigen-antibody reactions were compared between GM and commercial rice to assess the allergic risk of Cry proteins. This analysis showed no known allergen to have more than 35% aa sequence homology with modified Cry proteins in Bt rice over an 80 aa window or to have more than 8 consecutive identical aa. Sera from allergic patients showed some IgE reactivity via immunoblotting and enzyme-linked immunosorbent assay (ELISA), although no differences were seen between GM and commercial rice. Based on these results we conclude that GM rice with modified Cry proteins has no differences in its protein composition or allergenicity relative to commercial rice.

• Bulletin of the Korean Chemical Society
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• 제2권4호
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• pp.132-138
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• 1981

Ab initio molecular orbital calculations have been performed in an effort to determine which types of chemical interactions play essential roles for the system, , $H_2O+CH_2SH^+$, and $H_2O+ CH_2S$. The most important contribution to the interaction energy in controlling reaction path is the exchange repulsion energy, EX, which is largely responsible for the shape of the total interaction energy curve. In the ion-molecule reaction, prior protonation of thioformaldehyde or prior deprotonation of water leads to formation of the corresponding ionic adducts ($H_2O+CH_2SH$ and $HOCH_2S^-$), with no barrier to reaction, simulating specific acid and base catalysis, respectively, as in the case of formaldehyde. Otherwise, approach of water to thioformaldehyde gives rise to a completely repulsive interaction.

• Nuclear Engineering and Technology
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• 제37권4호
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• pp.327-362
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• 2005

The design, construction, and operation of a light water reactor (LWR) are subject to compliance with safety criteria specified for accident situations, such as loss-of-coolant accident (LOCA) and reactivity-initiated accident (RIA). Because reactor fuel is the primary source of radioactivity and heat generation, such a criterion is established on the basis of the characteristics and performance of fuel under the specific accident condition. As such, fuel behavior under accident situations impact many aspects of fuel design and power generation, and in an indirect manner, even spent fuel storage and management. This paper provides a comprehensive review of: the history of the current LOCA criteria, results of LOCA-related investigations on conventional and new classes of fuel, and status of on-going studies on high-burnup fuel under LOCA situations. The objective of the paper is to provide a better understanding of important issues and an insight helpful to establish new LOCA criteria for modem LWR fuels.

• BioChip Journal
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• 제12권4호
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• pp.287-293
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• 2018

Bacillus cereus can cause blood infections (i.e., sepsis). Its early detection is very important for treating patients. However, an antibody with high binding affinity to B. cereus is not currently available. Bacteriophage cell wall-binding domain (CBD) has strong and specific binding affinity to B. cereus. Here, we report the improvement in the sensitivity of an ATP bioluminescence assay for B. cereus detection using CBD-conjugated magnetic nanoparticles (CBD-MNPs). The assay was able to detect as few as 10 colony forming units (CFU) per mL and $10^3CFU\;per\;mL$ in buffer and blood. CBD-MNPs did not show any cross-reactivity with other microorganisms. These results demonstrate the feasibility of the ATP assay for the detection of B. cereus.

• International Journal of Oral Biology
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• 제43권4호
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• pp.201-207
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• 2018

Porphyromonas gingivalis is among the major etiological pathogens of chronic periodontitis. The virulence mechanisms of P. gingivalis is yet to be identified as its activity is largely unknown in actual disease process. The purpose of this study is to identify antigens of P. gingivalis expressed only in patients with chronic periodontitis using a unique immunoscreening technique. Change Mediated Antigen Technology (CMAT), an antibody-based screening technique, was used to identify virulence-associated proteins of P. gingivalis that are expressed only during infection stage in patients having chronic periodontitis. Out of 13,000 recombinant clones screened, 22 tested positive for reproducible reactivity with rabbit hyperimmune anti-sera prepared against dental plaque samples acquired from periodontitis patients. The DNA sequences of these 18 genes were determined. CMAT-identified protein antigens of P. gingivalis included proteins involved in energy metabolism and biosynthesis, heme and iron binding, drug resistance, specific enzyme activities, and unknown functions. Further analysis of these genes could result in a novel insight into the virulence mechanisms of P. gingivalis.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.297.1-297.1
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• 2002

Immunoassays are frequently used for an screening method to detect the presence of drugs in Urine. The main advantages of the method are well known -- simplicity of handling samples. rapidity. sensitivity. and specificity of analysis. However. it is also known that immunoassays exhibit cross-reactivity to related drugs and there are only limited specific immunoassays on the market. This study reports on the ability of TDx to detect urine samples obtained from suspects of taking over-the-counter medications and illegal drugs containing ATS. designer drugs. (omitted)

• 한국축산식품학회지
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• 제30권4호
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• pp.590-596
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• 2010

Meat and meat products are a potential source of food-borne pathogens, including Staphylococcus aureus, Salmonella spp., Escherichia coli O157:H7, and Bacillus cereus. A sensitive and specific PCR assay for the detection of these pathogens in meat and meat products was developed in this study, as part of a broader effort to reduce the potential health hazards posed by these pathogens. Initially, PCR conditions were standardized with purified DNA. Under standard conditions, the detection level for PCR was as low as 10 pg of purified bacterial DNA. After overnight growth of bacteria in a broth medium, as few as $10^2$ CFU of bacteria were detected by PCR assay. The primers employed in the PCR assay were found to be highly specific for individual organisms, and evidenced no cross-reactivity with heterologous organisms. Additionally, the multiplex PCR assays also amplified some target genes from the four pathogens, and multiplex amplification was obtained from as little as 10 pg of DNA, thus illustrating the excellent specificity and high sensitivity of the assay. In conclusion, this PCR-based technique provides a sensitive and specific method for the detection of S. aureus, Salmonella spp., E. coli O157:H7, and B. cereus in meat and meat products.