• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.1-10
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• 2012

Purpose: Cellulose acetate (CA) was blended with polyethyleneglycol (PEG) having different molecular weight at various mixing conditions to enhance melt-processibility of CA, which might prevent the harmful effect resulted from the introduction of phthalic plasticizer. Methods: To establish optimal plasticizing conditions, CA/PEG blends were examined under various plasticizing conditions: PEG concentration, molecular weight of PEG, and plasticzing temperature. Mechanical properties of the CA/PEG blends, as well as migration and exudation of the PEG, were performed in order to evaluate the efficiency of plasticization. Results: Compared to industrial CA resin plasticized by diethyl phthalate, CA/PEG blends exhibited similar thermal plasticization. It was established that the optimum condition was to blend 30~40 phr PEG with molecular weight 400 at $175{\sim}180^{\circ}C$. CA/PEG blend showed superior glassness, PEG stability, and mechanical properties. Conclusions: CA/PEG blends would be a eco-friendly glasses frame to substitute traditional CA glasses frame prepared phthalate plasticizers.

• Plant Biotechnology Reports
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• v.3 no.3
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• pp.175-182
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• 2009

Simple, reproducible, high frequency, improved plant regeneration protocol in Eastern Cottonwood (Populus deltoides) clones, WIMCO199 and L34, has been reported. Initially, aseptic cultures established from axillary buds of nodal segments from mature plus trees on MS liquid medium supplemented with $0.25mg\;1^{-1}$ KIN and $0.25mg\;1^{-1}$ IAA. Nodal and internodal segments were found to be extra-prolific over shoot apices during course of aseptic culture establishment, while $0.25mg\;1^{-1}$ KIN concentration played a stimulatory role in high frequency plant regeneration. Diverse explants, such as various leaf segments, internodes, and roots from in vitro raised cultures, were employed. Direct plant regeneration was at high frequency of 92% in internodes, 88% in leaf segments, and 43% in root segments. This led to the formation of multiple shoot clusters on established culture media with rapid proliferation rates. Many-fold enhanced shoot elongation and growth of the clusters could be achieved on liquid MS medium supplemented with borosilicate glass beads, which offer physical support for proliferating shoots leading to faster growth in comparison to semi-solid agar or direct liquid medium. SEM examination of initial cultures confirmed direct plant regeneration events without intervening calli. In vitro regenerated plants induced roots on half-strength MS medium with $0.15mg\;1^{-1}$ IAA. Rooted 5- to 6-week-old in vitro regenerated plants were transferred into a transgenic greenhouse in pots containing 1:1 mixture of vermicompost and soil at $27{\pm}2^{\circ}C$ for hardening and acclimatization. 14- to 15-week-old well-established hardened plants were transplanted to the field and grown to maturity. The mature in vitro raised poplar trees exhibited a high survival rate of 85%; 4-year-old healthy trees attained an average height of 8 m and an average trunk diameter of 25 cm and have performed well under field conditions. The regeneration protocol presented here will be very useful for undertaking genetic manipulation, providing a value addition to Eastern Cottonwood propagation in future.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1197-1200
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• 2010

Post-genomic 시대에 접어들면서 단백질의 기능의 주석이 중요한 문제로 떠오르기 시작하였다. 이런 단백질 기능을 예측하기 위해 단백질 상호작용(Protein-Protein interaction) 데이터를 이용한 방법들이 지난 10여 년간 발표되어왔다. 단백질 상호작용(Protein-Protein interaction) 데이터는 단백질들 간의 서열 등의 특징을 이용해 상호간의 연결 관련성이 있는 단백질끼리의 관계를 네트워크로 나타낸 자료이다. 현재 이러한 단백질 상호작용(Protein-Protein interaction) 데이터들은 MIPS, DIP, BioGrid등 약 5~6군데에서 제공되고 있다. 각각의 데이터는 다른 형식을 가지고 있고, 중복되는 정보도 포함하고 있다. 여러 연구 방법에서 데이터를 사용할 때 한군데에서만 추출하기 보다는 여러 데이터에서 추출하는 경우가 많기 때문에 다른 형식의 데이터를 이용하는데 불필요한 수고가 들어가게 된다. 때문에 여러군데의 데이터를 한 가지 형식으로 맞추어 통합적으로 구축하여 연구 시 데이터 사용에 용이하도록 설계 하였다. 또한 발표된 단백질 기능 예측 방법에 대한 정리를 통해 앞으로의 연구를 하는데 있어서 필요한 자료를 얻고 열람할 수 있도록 설계하였다. 이를 통해 관련 연구를 하거나 관심이 있는 사람들의 데이터를 검색하는데 많은 도움이 될 것이다.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.18-18
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• 2005

Photoinduced electron transport process in nature such as photoelectric conversion and long-range electron transfer in photosynthetic organisms are known to occur not only very efficiently but also unidirectionally through the functional groups of biomolecules. The basic principles in the development of new functional devices can be inspired from the biological systems such as molecular recognition, electron transfer chain, or photosynthetic reaction center. By mimicking the organization of the biological system, molecular electronic devices can be realized $artificially^{1)}$. The nano-fabrication technology of biomolecules was applied to the development of nano-protein chip for simultaneously analyzing many kinds of proteins as a rapid tool for proteome research. The results showed that the self-assembled protein layer had an influence on the sensitivity of the fabricated bio-surface to the target molecules, which would give us a way to fabricate the nano-protein chip with high sensitivity. The results implicate that the biosurface fabrication using self-assembled protein molecules could be successfully applied to the construction of nanoscale bio-photodiode and nano-protein chip based on electrical detection.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.575-580
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• 2010

In this work, the electrophoretic motion of dsDNA molecule represented by a polymer through an artificial nano-pore in a membrane is simulated using the numerical method combining the lattice Boltzmann and Langevin molecular dynamic method. The polymer motion is represented by Langevin molecular dynamics technique while the fluid flow is taken into account by fluctuating lattice-Boltzmann method. The hydrodynamic interactions between the polymer and solvent in a confined space with a membrane having a hole are considered explicitly through the frictional and the random forces. The electric field intensity over the space is obtained from a finite difference method. Initially, the polymer is placed at one side of the space, and an electric field is applied to drive the polymer to the other side of the space through the nano-pore. In future, we plan to study the effect of the polymer size and the electric field on the electrophoretic velocity.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.237-242
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• 2013

This experiment was conducted for the purpose of developing such a sensor that can quickly sense dopamine concentration by using chitosan-gold nanoshell. Chitosan nano particles were reacted with gold nano particles so as to synthesize chitosan-gold nanoshell, and the size of the synthesized product was about 150 nm. When dopamine was reacted with chitosan-gold nanoshell, the size of it was not definitely changed, but dopamine was well reacted with chitosan-gold nanoshell, and it generated SERS (surface-enhanced Raman scattering), which led to a clear difference in the intensity of Raman scattering within the range of dopamine concentration (1 mM-10 mM). When Raman scattering was intensity marked on chitosan-gold nanoshell by employing a calibration curve according to dopamine concentration, a straight line whose margin of error was narrow was earned.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2018.10a
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• pp.248-248
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• 2018

• Polymer Science and Technology
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• v.26 no.3
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• pp.215-220
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• 2015

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.215-215
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• 2020

• Membrane Journal
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• v.18 no.3
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• pp.206-213
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• 2008

Poly(vinylidene fluoride) (PVDF) membrane surfaces were modified using surface modifying macromolecules (SMMs). The Zonyl BA-L as SMM was used and the various PVDF membranes containing 0 to 2 wt% SMM were prepared. The resulting membranes were characterized through SEM, contact angle measurements and pervaporation separation of water-ethanol system. SMM layers were created in the surface regions of PVDF membranes by SEM images and the contact angles were increased more than untreated PVDF membranes. The pervaporation was carried out at 50, 60 and $70^{\circ}C$, and the PVDF membranes containing 1 and 2 wt% SMM were used for 10, 20, 50 wt% water in the binary water/ethanol mixtures and pure water. PVDF/2 wt% Zrlnyl BA-L membrane showed the permeability 5.3 $g/m^2hr$ and separation factor 287 at $50^{\circ}C$ for water : ethanol = 10 : 50 solution.