• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.922-927
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• 2001

In an effort to regulate the mammalian cell behavior in entrapment with a gel, we have functionalized hydrogels with the putative cell-binding (-Arg-Gly-Asp-)(RGD) domain. An adhesion molecule of Gly-Arg-Gly-Asp-Ser (GRGDS) peptides, a cell recognition ligand, was induced into thermo-reversible hydrogels, composed of N-isopropylacrylamide with small amounts of acrylic acid (typically 2-5 $mol\%$ in feed), as a biomimetic extracellular matrix (ECM). The GRGDS containing a p(NiPAAm-co-AAc) copolymer gel was studied in vitro for its ability to promote the spreading and viability of cells by introducing a GRGDS sequence. Hydrogel with no adhesion molecule was a poor ECM for adhesion, permiting spreading of only $3\%$ of the seeded cells for 36h. By immobilizing the peptide linkage into the hydrogel, the conjugation of RGD promoted $50\%$ of proliferation for 36h. However, the GREDS sequence, nonadhesive peptide linkage, conjugated hydrogel showed only $5\%$ of the seeded cell for the same time period. In addition, with the serum-free medium, only GRGDS peptides conjugated to hydrogel was able to promotecell spreading, while there was no cell proliferation in the hydrogel without GRGDS. Thus, the GRGDS peptide-conjugated thermo-reversible hydrogel specifically mediated the cell spreading. This result suggests that utilization of peptide sequences conjugating with the cell-adhesive motifs can enhance the degree of cell surface interaction and influence the long-term formation of ECM in vitro.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.3
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• pp.167-172
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• 2004

The kinesin proteins (KIFs) make up a large superfamily of molecular motors that transport cargo such as vesicles, protein complexes, and organelles. KIF5 is a heterotetrameric motor that conveys vesicles and plays an important role in neuronal function. Here, we used the yeast two-hybrid system to identify the neuronal protein(s) that interacts with the tail region of KIF5 and found a specific interaction with ${\beta}III$ spectrin. The amino acid residues between 1394 and 1774 of ${\beta}III$ spectrin were required for the interaction with KIF5C. ${\beta}III$ spectrin also bound to the tail region of neuronal KIF5A and ubiquitous KIF5B but not to other kinesin family members in the yeast two-hybrid assay. In addition, these proteins showed specific interactions, confirmed by GST pull-down assay and co-immunoprecipitation. ${\beta}III$ spectrin interacted with GST-KIF5 fusion proteins, but not with GST alone. An antibody to ${\beta}III$ spectrin specifically co-immunoprecipitated KIF5s associated with ${\beta}III$ spectrin from mouse brain extracts. These results suggest that KTF5 motor proteins transport vesicles or organelles that are coated with ${\beta}III$ spectrin.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1337-1350
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• 2023

Caproic acid is a precursor substance for the synthesis of ethyl caproate, the main flavor substance of nongxiangxing baijiu liquor. In this study, Clostridium butyricum GD1-1, a strain with high caproic acid concentration (3.86 g/l), was isolated from the storage pit mud of nongxiangxing baijiu for sequencing and analysis. The strain's genome was 3,840,048 bp in length with 4,050 open reading frames. In addition, virulence factor annotation analysis showed C. butyricum GD1-1 to be safe at the genetic level. However, the annotation results using the Kyoto Encyclopedia of Genes and Genomes Automatic Annotation Server predicted a deficiency in the strain's synthesis of alanine, methionine, and biotin. These results were confirmed by essential nutrient factor validation experiments. Furthermore, the optimized medium conditions for caproic acid concentration by strain GD1-1 were (g/l): glucose 30, NaCl 5, yeast extract 10, peptone 10, beef paste 10, sodium acetate 11, L-cysteine 0.6, biotin 0.004, starch 2, and 2.0% ethanol. The optimized fermentation conditions for caproic acid production by C. butyricum GD1-1 on a single-factor basis were: 5% inoculum volume, 35℃, pH 7, and 90% loading volume. Under optimal conditions, the caproic acid concentration of strain GD1-1 reached 5.42 g/l, which was 1.40 times higher than the initial concentration. C. butyricum GD1-1 could be further used in caproic acid production, NXXB pit mud strengthening and maintenance, and artificial pit mud preparation.

• Korean Journal of Materials Research
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• v.22 no.12
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• pp.643-649
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• 2012

Coatings composited with alumina and Perfluoro alkoxyalkane (PFA) resin were deposited on stainless steel plate (SUS304) to further improve corrosion resistance. Plate (ca. $10{\mu}m$) and/or nanosize (27~43 nm) alumina used as inorganic additives were mixed in PFA resin to make alumina-fluoro composite coatings. These coatings were deposited on SUS304 plate with wet spray coating and then the film was cured thermally. According to the amount and ratio of the two kinds of alumina having plate morphology and nano size, corrosion resistance of the film was evaluated under strong acids (HF, HCl) and a strong base (NaOH). The film prepared with the addition of 5~10 wt% alumina powders in PFA resin showed corrosion resistance superior to that of pure PFA resin film. However, for the film prepared with alumina content above 10 wt%, the corrosion resistance did not improve with the physical properties, such as surface hardness and adhesion. The film prepared with plate/nanosize (weight ratio = 1/2) alumina especially enhanced the surface hardness and corrosion resistance. This can be explained as showing that the plate and the nanosize alumina dispersed in PFA resin effectively suppressed the penetration of cations and anions due to the long penetration length and fewer defects that accompany the improved surface hardness under a serious environment of 10% HF solution for over 120 hrs.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.6
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• pp.490-500
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• 2011

The paradigm that ships are navigated by means of analog navigation devices and caption's experiences is shifted to that ships can be navigated by digital and autonomous navigation systems due to the rapid development of electronics and communication technologies. Hence, all systems deployed in a ship are automated and integrated since corresponding ship systems are not individually operated but integrated and managed under common operating system. In this paper, we overview recent research projects targeted for digitally integrated ships (referred to as digital ships), outline IEC 61162 series, specifying digital interface standards for digital ships, and finally present several issues for further improvement of the IEC 61162 series. In addition, we broadly categorize digital ships into three systems consisting of multiple sub-systems, including a navigation system, a power system, and a automation system in the aspect of operation and function. Corresponding interfacing range and method, as well as interface specification and data types of one system in a digital ship are also described according to sub-systems, respectively.

• Polymer(Korea)
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• v.33 no.2
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• pp.111-117
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• 2009

This study aims to verify for humans the suitability of the enzyme-fixed hydrogel used for the patch sensor of the blood sugar testing system without blood sampling, which utilizes reverse iontophoresis. Using acrylate monomers, hydrogel was synthesized to which a certain unit of enzyme is fixed. In order to analyze the material property of the synthesized hydrogel, a structural analysis was performed using FT-IR spectroscopy, while the DSC was used to verify the thermal stability. In addition, with the UV-Vis spectrophotometer, it was verified that the degree of active enzyme is at least 50% greater than the standard product. The SEM was used to verify secure fixation of the enzyme onto the surface. As a result, it was observed that the enzyme is successfully fixed to the surface. Since the hydrogel makes direct contact with a patient's skin, it is essential to evaluate the toxicity when making direct contact with the skin. For that purpose, various sets of tests were undertaken according to the ISO 10993-cytotoxicity, intracutaneous reactivity, skin irritation test and maximization sensitization. Consequently, it was successfully verified that the enzyme-fixed hydrogel have bioavailability.

• Korean Journal of Materials Research
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• v.27 no.1
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• pp.12-18
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• 2017

Transparent organic-inorganic hybrid hard coating films were prepared by the addition of $SiO_2$ or $ZrO_2$, as an inorganic filler to improve the hardness property, filler was highly dispersed in the acrylic resin. To improve the compatibility in the acrylic resin, $SiO_2$ or $ZrO_2$ is surface-modified using various silanes with variation of the modification time and silane content. Depending on the content and kind of the modified inorganic oxide, transparent modified inorganic sols were formulated in acryl resin. Then, the sols were bar coated and cured on PET films to investigate the optical and mechanical properties. The optimized film, which has a modified $ZrO_2$ content of 4 wt% markedly improved in terms of the hardness, haze, and transparency as compared to neat acrylate resin and acrylate resin containing modified $SiO_2$ content of 8 wt%. Meanwhile, the low transparency and high haze of these films slowly appeared at $SiO_2$ content above 10 wt% and $ZrO_2$ content of 5 wt%, but the hardness values were maintained at 2H and 3H, respectively, in comparison with the HB of neat acrylate resin.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.33-48
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• 2009

Forests store carbon dioxide ($CO_2$), one of the major factors of global warming, in vegetation and soils through photosynthesis process. In addition, woods deposit $CO_2$ for a long term until the harvested wood is decomposed or burned, and deforested areas could be expanded the carbon sinks through reforestation. Forests are a lso able to decrease temperature through transpiration and contribute to control the micro climate in global climate systems. Consequently, forests are considered as one of major sinks of greenhouse gases for mitigating global warming. It is very important to develop a Korea specific forest carbon flux model for preparing adaptation measures to climate change. In this study, we compared the climate change impact models in forests developed in foreign countries and analyzed the applicability of the models to Korean forest. Also we selected models applicable to Korean forest and suggested approaches for developing Korean specific model.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.1
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• pp.79-86
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• 2022

In general, since the types and types of ships, so complex and various variables are included to measure the amount of construction work. In addition, it is mot easy to predict the schedule or the number of working hours before ship construction, and it is also mostly inaccurate. As a result, the master plan is manually drawn up by the expert's experience, but there are limitations due to various factors. Medium and large shipyards are operating APS(Advanced Planning and Scheduling) system that reflects industrial characteristics to improve productivity in the planning stage, and utilize information from systems such as ERP(Enterprise Resource Planning) system and MES (Manufacturing Execution System). On the other hand, small shipyards rely mostly on manual work such as Excel work based on the experience of the workers. Therefore, this study intends to develop a master plan management system that can efficiently manage the production process from the business planning stage in consideration of the characteristics of small shipyards.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.169-177
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• 2024

In this paper, the effect on cement clinker and cement quality was studied to prove the effect of reducing the sintering temperature of cement clinker as a mineralizer to recycle fluorine based semiconductor sludge, an industrial by-product. In addition, a verification study was conducted to compare the properties of clinker and cement at different temperatures when natural fluorite, previously used as a mineralizer, was used. As a result of the study, semiconductor sludge showed sufficient effectiveness as a mineralizer and could replace natural fluorite, an existing mineralizer.