• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.903-904
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• 2010

• Proceedings of the Korean Society of Rheology Conference
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• 2006.06a
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• pp.171-174
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• 2006

• Proceedings of the Microbiological Society of Korea Conference
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• 1998.04a
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• pp.44.2-44.2
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• 1998

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.53.1-56
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• 2000

Langmuir-Blodgett(LB) technique is the best candidate for the future molecular electronic devices. But, these molecular thin film devices require the bulk properties that are influenced by the molecular orientations. So, this is of current interest in molecular electronic device fabrications of new materials. In this study, quantitative evaluation of molecular orientation in LB films of PAAS was performed by comparing the absorption intensities of the FT-IR transmission and reflection-absorption spectra and the polarized UV/visible absorption spectra. It was found that the polar angle($\theta$) of the dipole moment is about 68$^{\circ}$and the tilting angle of the alkyl chain is about $11.5^{\circ}$ .

• Journal of the Korean Graphic Arts Communication Society
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• v.7 no.1
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• pp.65-72
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• 1989

Modified phenolics can have a retarding effect on the gelation of wood oil. Modified phenolic resins can be used in media for paint, varnishes, primers, overprinting varnishes, litho, letterpress and rotogravure inks. Varnishes based on rosin phenolic are faster drying, have better durability, are harder and glosser, and have greater resistance to water than ones based on ester gums. These physical properties is concerned with molecular weight distribution of rosin modified phenol resin. This paper was studied about molecular weight distribution of rosin phenolics which were prepared between $130~250^{\circ}C$. The results were as follows: 1) Average molecular weights inereased with increasing reaction temperature. 2) $M_w/M_n$ were from 3.43 to 46.44 with increasing reaction temperature and so the molecular weight distributions were changed from random distribution to broad distribution. 3) The relation ship between intrinsic viscosity and weight average molecular weight was follows: $[{\;}{\;}]={\;}1{\times}{\;}10^{-6}M_w,{\;}M_w=M_w$ 4) Esterification reaction between the acid group of rosin and polyol was started about $230^{\circ}C$$.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.504-508
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• 2006

Molecular weight of polyaniline is controlled in the range of oligomer to low molecular weight by controlling the ratio of aniline dimer (p-aminodiphenylamine) to monomer. Aniline dimers act as nucleation sites in chain growth during the polymerization of aniline. The molecular weights of polyanilines are estimated by GPS and relative viscosity measurement. The physical and chemical properties of polyanilines with various molecular weights are studied by UV-Vis, FT-IR, and electrical conductivity measurements.

• Bulletin of the Korean Chemical Society
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• v.24 no.11
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• pp.1637-1640
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• 2003

Quaternary ammonium groups were introduced to Starburst polyamidoamine (PAMAM) dendrimers for a gene carrier. These quaternary dendritic carriers exhibited reduced cytotoxicity on 293T cells compared to parent dendrimers examined and their transfection efficiency were similar with parent dendrimers. Quaternization could be a promising tool to improve properties of dendrimers as a gene delivery carrier.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
• /
• pp.53-56
• /
• 2000

Langmuir-Blodgett(LB) technique is the best candidate for the future molecular electronic devices. But, these molecular thin film devices require the bulk properties that are influenced by the molecular orientations. So, this is of current interest in molecular electronic device fabrications of new materials. In this study, quantitative evaluation of molecular orientation in LB films of PAAS was performed by comparing the absorption intensities of the FT-IR transmission and reflection-absorption spectra and the polarized UV/visible absorption spectra. It was found that the polar angle( $\theta$ ) of the dipole moment is about 68$^{\circ}$ and the tilting angle of the alkyl chain is about 11.5$^{\circ}$

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.4 no.2
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• pp.115-120
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• 2018

In recent years, many researchers have attempted to make use of 2D nanoparticles as molecular imaging probes since extensive investigations proved that 2D nanoparticles in the body tends to accumulate certain lesions by enhanced permeability and retention (EPR) effect. For example, graphene and carbon nitride which have high surface area and modifiable properties showed good biocompatibility and targetability when it used as imaging probes. However, poor dispersibility in physiological mediums and its uncontrolled size limited its usage in bio-application. Therefore, oxidation process and mechanical exfoliation have been developed for overcoming these problems. In this paper, we highlight the several major methods to synthesize biocompatible 2D nanomaterials like graphene and carbon nitride especially for molecular imaging study including positron emission tomography (PET).

• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.335-347
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• 2009

This review covers current developments in molecular-based studies of the structure and function of carboxylesterases. To allay the confusion of the classic classification of carboxylesterase isozymes, we have proposed a novel nomenclature and classification of mammalian carboxylesterases on the basis of molecular properties. In addition, mechanisms of regulation of gene expression of carboxylesterases by xenobiotics, and involvement of carboxylesterase in drug metabolism are also described.