• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.255-258
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• 2013

• Applied Microscopy
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• v.42 no.4
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• pp.212-217
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• 2012

This paper reports the effects of post-annealing of ZnO thin films on their microstructure and the device performance of the transistors fabricated from the films. From X-ray diffraction and transmission electron microscopy characterization, we uncovered that the grain size increased with the annealing temperature escalating and that the film stress shifted from compressive to tensile due to the grain size increment. Electrical characterization revealed that the grain size increase damaged the device performance by drastically lifting the off-current level. By annealing the devices in an $O_2$ ambient (instead of air), we were able to suppress the off-current while improving the electron mobility.

• Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.177-185
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• 2013

The development of species-specific fish cell lines has become a valuable tool for biological research. In recent years, marine medaka Oryzias dancena has been recognized as a good experimental model fish but there are no reports of establishment of cell lines from this fish. In this study, two cell lines from O. dancena blastula embryos were established from 41 total trials (4.9%). The two cell lines displayed typical in vitro morphology and have been cultured for >121 passages, which corresponds to 293 days. The doubling times of the cell lines were 29.84 and 28.59 h, respectively, and both possessed the potential to expand in a clonal manner, albeit with significant differences between the two cell lines. The absence of any of the four main medium supplements; i.e., fish serum, fetal bovine serum, basic fibroblast growth factor, and medaka embryo extract, significantly inhibited growth. The proportion of cells possessing normal chromosome number was 45% and 46.7% of the cell lines, respectively. Taken together, two cell lines that proliferate continuously were established from marine medaka and these cell lines may provide a basic tool for characterizing the unique features of this fish species.

• Mass Spectrometry Letters
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• v.11 no.4
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• pp.77-81
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• 2020

Characterization of the various chemical aspects of composite polymers is important for quality control of manufactured polymers. In this study, we compared three suitable matrices (α cyano-4-hydroxycinnamic acid [CHCA], 2,5 dihydroxy benzoic acid [2,5-DHB], and dithranol), to characterize various synthetic polymers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Although the spectra obtained with the CHCA and 2,5-DHB matrices were generally good, in certain samples ghost peaks disappeared only when dithranol was used as the matrix. Furthermore, we examined the use of sodium trifluoroacetate (NaTFA) as an additive to reduce interference by metals and copolymers in the spectra. In conclusion, appropriate selection of a matrix, according to the characteristics of the polymer, and the use of additives to improve sensitivity are important considerations for polymer analysis and development.

• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.1055-1060
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• 2004

A new inhibitor for peptidylprolyl cis-trans isomerase (PPIase) has been isolated from Ganoderma lucidum and purified to homogeneous state by organic solvent extraction. The purified PPIase inhibitor (GPI) is assumed to be a membrane-associated glycoprotein. GPI inhibits specifically the bovine brain PPIase, a cyclophilin, and has no effect on the FKBP activity. The results of our chemical modification study of GPI indicate the presence of Lys residue(s) at or near its binding site. Like CsA-cyclophilin complex, GPI-bovine brain PPIase complex strongly inhibits the calcineurin activity in vitro, suggesting the possible involvement of GPI in immunomodulating pathway by the formation of PPIase-inhibitor-calcineurin complex.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.4
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• pp.651-654
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• 1998

The layered basic zinc p-toluenesulfonates has been directly synthesized by the surface modification. The chemical formula of layered basic zinc p-toluenesulfonate is determined by CHNS and TG-DTA. From the X-ray diffraction data and the guest size, the orientation of the p-toluenesulfonate onto the zinc hydroxide layer is determined. The molecular plane of the p-toluenesulfonate lies perpendicular to the zinc hydroxide layers.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.389-393
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• 2004

In this paper, we introduce the concept of level subgroups of an intuitionistic fuzzy subgroup, and study some properties of level subgroups in the first part of the paper. These level subgroups in turn play an important role in the characterization of all intuitionistic fuzzy subgroups of a prime cyclic group.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.411.2-411.2
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• 2014

The design of DNA nanostructures is of fundamental importance, the intrinsic value of DNA as a building-block material lies in its ability to organize other bio-molecules with nanometer-scale spacing. Here, we report the fabrication of DNA scaffolds with nano-pores (<10 nm size) that formed easily without the use of additives (i.e., avidin, biotin, polyamine, or inorganic materials) into large-scale structures by assembling DNA molecules at near room temperature ($30^{\circ}C$) and low pH (~5.5). Protein immobilization results also confirmed that a fibronectin (FN) proteins/large scale DNA scaffolds/aminopropylytriethoxysilane (APS)/SiO2/Si substrate with high sensitivity formed in a well-defined manner. The DNA scaffolds can be applied for use with DNA-based biochips, biophysics, and cell biology.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.513-516
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• 1987

Hydrogenated amorphous silicon (a-Si:H) films have been deposited, for thye first time, by a remote plasma chemical vapor deposition. The hydrogen radical play a important role to control the deposition rate, The bonded hydrogen content to silicon is independent of hydrogen partial pressure in the plasma. Optical gap of deposited a-Si:H lies between 1.7eV and 1.8eV and all samples have sharp absorption edge. B-doped a-Si:H films by a RPECVD has a high doping efficiency compared with plasma CVD. The Fermi level of 100ppm B-doped film lies at 0.5eV above valence band edge.

• Mass Spectrometry Letters
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• v.11 no.4
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• pp.90-94
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• 2020

Interest in aspects of industrialization relating to human health has increased. Accordingly, the use of labels such as 'natural foods' and 'organic ingredients' has become more widespread, and greater emphasis is being placed on improving quality of life. Water is an essential element for human life, and water quality has a significant impact on human health. However, technology that can precisely determine the substances present in water is still lacking. This study was conducted to establish a complete mass spectrometry process, from pretreatment to analysis, to measure and characterize natural organic matter (NOM) in Korean spring water samples. Salts and other matrices were removed from the samples using solid-phase extraction (SPE) with two different columns (PPL and C18). After establishing an accurate analysis method, the experimental results were evaluated based on Van Krevelen diagrams and analysis of molar O/C and H/C ratios. The method for characterizing NOM introduced herein should facilitate evaluation of water quality.