• Journal of Marine Bioscience and Biotechnology
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• v.6 no.1
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• pp.17-25
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• 2014

Periodically, harmful algal blooms (HABs) have occurred, with impacts on various areas including public health, tourism, and aquatic ecosystems, especially aquacultured and caged fisheries. To prevent or manage invasions of HABs into fish farms on an emergency basis, many methods have been proposed. Frequently over the past 30 years in coastal countries, treatments of clay and clay mixed with polyaluminum chloride (PAC) and chitosan have been tested for HAB-removal effectiveness in both the laboratory and the field. In Korea, yellow loess clay (hwangto) has been dispersed using electrolytic clay dispensers, both to decrease the amount of yellow loess clay's usage in containers and enhance HAB-removal efficiency. However, this emergency method has limitations, among which is the requirement for more effective controlling agents for field applications. Thus, in this paper, we review technologies for clay-based red tides prevention and control and their limitations, and, further, introduce next-generation algicidal technologies for the emergency protection of fish farms.

• Korean Journal of Materials Research
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• v.18 no.6
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• pp.334-338
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• 2008

The purpose of this study is to characterize various electrolytes on electrochemical mechanical planarization (ECMP). The ECMP system was modified from conventional CMP system to measure the potentiodynamic curve and removal rate of Cu. The potentiodynamic curves were measured in static and dynamic states in investigated electrolytes using a potentiostat for the evaluation of the polishing behavior on ECMP. KOH (alkaline) and $NaNO_3$ (salt) were selected as electrolytes which have high conductivity. In static and dynamic states, the corrosion potential decreased and the corrosion current increased as a function of the electrolyte concentration. But, the electrochemical reaction was prevented by mechanical polishing effect in the dynamic state. The static etch and removal rate were measured as functions of concentration and applied voltage. When $NaNO_3$ was used, the dissolution was much faster than that of KOH. It was concluded that the removal rate was strongly depended on electrochemical dissolution. The removal rate increased up to 350 nm/min in $NaNO_3$ based electrolyte.

• Macromolecular Research
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• v.17 no.6
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• pp.424-429
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• 2009

In this study, we demonstrate that the biological unnatural amino acid incorporation method can be utilized in vivo to synthesize an alkyne-terminated telechelic protein, Synthesis of terminally-functionalized polymers such as telechelic polymers is recognized to be important, since they can be employed usefully in many areas of biology and material science, such as drug delivery, colloidal dispersion, surface modification, and formation of polymer network. The introduction of alkyne groups into polymeric material is particularly interesting since the alkyne group can be a linker to combine other materials using click chemistry. To synthesize the telechelic recombinant protein, we attempted to incorporate the L-homopropargylglycine into the recombinant GroES fragment by expressing the recombinant gene encoding Met at the codons for both N- and C-terminals of the protein in the Met auxotrophic E. coli via Hpg supplementation. The Hpg incorporation rate was investigated and the incorporation was confirmed by MALDI-TOF analysis of the telcchelic recombinant protein.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.110-111
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• 2013

FcBP consisting of 13 amino acids specifically binds to Immunoglobulin G Fc domain. Initially, we utilized this peptide for preparation of antibody chip as a PEG composite for enhanced solubility. After then, the peptide conjugate was immobilized on agarose resin, resulting in highly efficient affinity column for antibody purification. The efficiency was comparable to commercial Protein A column. Recently, this peptide was conjugated with cell penetrating peptide (CPP) on a backbone of GFP, affording antibody transducer, which carries antibody into live cells by simple mixing of antibody and the transducer in cell culture media. Antibody transduction into cells was monitored by live cell imaging. More recently, the FcBP was fused to ferritin cage, which consists of 24 ferritin protein molecules. The FcBP-ferritin cage showed greatly increased binding affinity to human IgG. Its binding was analyzed by QCM and SPR analysis. Finally, it was selectively delivered by Herceptin to SKBR3, a breast cancer cell, over MCF10A, non-tumorigenic cells (Fig. 1). Fig. 1. Fluorescent microscopic images of SKBR3 breast cancer cells (A~C) and MCF10A breast cells (D~F) treated with Cy3-trastuzumab/fFcBP-Pf_Fn complexes. Trastuzumab and FcBP-Pf_Fn, which were labeled with Cy3 (Cy3-trastuzumab) and fluorescein (fFcBP-Pf_Fn), respectively, selectively targeted SKBR3 over MCF10A.

• The Korean Journal of Food And Nutrition
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• v.21 no.2
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• pp.135-142
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• 2008

This study investigated to develop new functional yogurt added domestic yuza(Citrus junos). In order to make the most effective yogurt, yuza extract and fructose were mixed at different proportions. DPPH free radical scavenging activity of yuza yogurts increased dependent on concentration. The results of the DPPH free radical scavenging activity, the 1% yuza yogurt was proven to be the best. The overall sensory score for yogurt made from adding 1% yuza ethanol extract was the best of tested yogurts. The antioxidant activity(DPPH free radical scavenging activity) was the highest in 1% yuza yogurt. The quality characteristics of prepared yogurt were evaluated in terms of acid production(pH and titratable acidity), viscosity, color and levels of lactic acid bacteria during storage period. During storage, the quality of yogurt made from adding yuza extract was better than control(without yuza extract). The sedimentation of curd was repressed a little by adding 1% yuza extract.

• Korean journal of food and cookery science
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• v.33 no.2
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• pp.198-208
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• 2017

Purpose: To improve the quality of basic gluten-free rice bread composed of white rice flour, salt, sugar, yeast, skim milk powder, olive oil, and water, the effects of transglutaminase (TGase), whey protein (WP), propylene glycol alginate (PGA), and hydroxypropylmethylcelluose (HPMC) were investigated. Methods: TGase, WP, PGA, and HPMC were added to rice flour cumulatively. The pasting properties of rice flour blends as well as volume, shape, color value, textural properties and sensory evaluation of basic rice bread (RB1) RB1+TGase (RB2), RB1+TGase+WP (RB3), RB1+TGase+WP+PGA (RB4), and RB1+TGase+WP+PGA+HPMC (RB5) were compared. Results: Consistency of rice batter increased upon addition of TGase, WP and PGA, and RB3 and RB4 had higher specific volumes than others. PGA improved volume, crumb air cell uniformity, and resilience but lowered elasticity and moistness of RB. HPMC increased, hardness, moistness and softness, and slightly reduced volume. Conclusion: Therefore, it is suggested that hydrocolloids, PGA and HPMC may be necessary to improve volume, crumb structure, textural properties and overall eating quality of gluten-free rice bread.

• Journal of Microbiology and Biotechnology
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• v.23 no.2
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• pp.218-224
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• 2013

The aldo-keto reductases catalyze reduction reactions using various aliphatic and aromatic aldehydes/ketones. Most reductases require NADPH exclusively as their cofactors. However, NADPH is much more expensive and unstable than NADH. In this study, we attempted to change the five amino acid residues that interact with the 2'-phosphate group of the adenosine ribose of NADPH. These residues were selected based on a docking model of the YOL151W reductase and were substituted with other amino acids to develop NADH-utilizing enzymes. Ten mutants were constructed by site-directed mutagenesis and expressed in Escherichia coli. Among them, four mutants showed higher reductase activities than wild-type when using the NADH cofactor. Analysis of the kinetic parameters for the wild type and mutants indicated that the $k_{cat}/K_{m}$ value of the Asn9Glu mutant toward NADH increased 3-fold. A docking model was used to show that the carboxyl group of Glu 9 of the mutant formed an additional hydrogen bond with the 2'-hydroxyl group of adenosine ribose. The Asn9Glu mutant was able to produce (R)-ethyl-4-chloro-3-hydroxyl butanoate rapidly when using the NADH regeneration system.

• Environmental Engineering Research
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• v.22 no.2
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• pp.131-140
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• 2017

The use of electronic cigarettes (ECs) is recognized as a source of many pollutants, just like conventional cigarettes (CCs). The analysis of EC aerosol samples has confirmed the presence of various metallic species. Most of these metals originate from various parts of the cartomizer, e.g., solder joints, wires, and silicate beads. The metal concentration levels in EC samples were shown to be generally two to four orders of magnitude lower than those of CCs. However, the use of ECs can still pose significant human health hazards as consumers are exposed to the toxicity of those metals and many other hazardous pollutants released simultaneously via the vaping of ECs. The review also describes the detection and quantification of various metals in ECs and CCs. This review was carried out to assess the level of metal species released from ECs and to suggest proper guidelines to control consumer exposure.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.2
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• pp.76-80
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• 2013

For further improvement of osseo-integration of bone crystal with a dental implant, a design optimization study is carried out for various holes inside its body to deliver bioactive materials and the effect of bioactive material injection on the bone crystal growing. When bioactive material is absorbed, the bone crystal can grow into holes, which would increase the strength of implant bonding as well as a surface integration. The stress concentrations near the uppermost outlet holes were reduced with increasing the number of outlet holes. A design improvement in the uppermost outlet was shown to be effective in reducing the stress concentration. For design parameters under consideration in this study, total area of outlet of 6.38 $mm^2$ and maximum stress of 1.114 MPa, which corresponds to type 6-C. It is due to the minimization of maximum stress and total area of outlet. The design of the outlet facing down was more effective in reducing the maximum stress value compared with a horizontal symmetry.

• Journal of the Korean Ceramic Society
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• v.53 no.6
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• pp.682-688
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• 2016

In $TiO_2$-CuO systems, low-temperature sinterability was investigated by a conventional sintering method. Sintering temperatures were set at under $950^{\circ}C$, at which the volume diffusion is inactive. The temperatures are less than the melting point of Ag ($961^{\circ}C$), which is often used as an internal conductor in low-temperature co-fired ceramic technology. To optimize the amount of CuO dopant, various dopant contents were added. The optimum level for enhanced densification was 2 wt% CuO. Excess dopants were segregated to the grain boundaries. The segregated dopants supplied a high diffusion path, by which grain boundary diffusion improved. At lower temperatures in the solid state region, grain boundary diffusion was the principal mass transport mechanism for densification. The enhanced grain boundary diffusion, therefore, improved densification. In this regard, the results of this study prove that the sintering mechanism was the same as that of activated sintering.