• Title/Summary/Keyword: Center for nanotechnology in society

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Fabrication of transparent conducting films of carbon nanotubes using a spray method

  • Geng, Hong Zhang;Lee, Kyu;Song, Young-Il;Kim, Gil-Yong;Choi, Ha-Kyu;Jun, Bae-Jung;Ahn, Kay-Hyeok;Lee, Young-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.525-528
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    • 2006
  • Transparent conducting films were fabricated on polyethylene terephthalate substrate by a spray method using double-walled carbon nanotubes dispersed in organic solvent and water-based solution. We analyzed the films by absorption spectra, sheet resistance, and scanning electron microscopy. Transparent conducting films with high uniformity and high transparency were fabricated by the spray method. We found that the dispersion particularly nanodispersion of CNTs was of crucial importance to improve the film performance.

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A Review on the Application of Nanotechnology in Food Processing and Packaging

  • Cho, Seong-In;Kim, Yong-Rok;Lee, Joon Woo;So, Dae-Sup;Cho, Yong-Jin;Suh, Hyun Kwon;Park, Tu San;Oh, Seoung-Im;Im, Ji-Eun
    • Food Engineering Progress
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    • v.14 no.4
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    • pp.283-291
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    • 2010
  • Currently, nanotechnology is widely applied in various industrial fields and is rapidly emerging as a promising future technology. In food industries, nanotechnology is used to enhance food quality and safety. Numerous cutting-edge studies on the advantages of nanotechnology have been conducted in the fields of food processing, food ingredients and additives, food packaging, and food engineering for optimal health. The market for these areas of research has grown steadily, and is expected to continue to do so. Because of this, R&D for nanotechnology that can be used effectively in food industries is being performed by several companies, as well as in academic research institutions around the world. This review describes the recent global R&D trends that have been in progress for two key areas: food processing and food packaging.

Cloning and Characterization of Filamentous Fungal S-Nitrosoglutathione Reductase from Aspergillus nidulans

  • Zhou, Yao;Zhou, Shengmin;Yu, Haijun;Li, Jingyi;Xia, Yang;Li, Baoyi;Wang, Xiaoli;Wang, Ping
    • Journal of Microbiology and Biotechnology
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    • v.26 no.5
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    • pp.928-937
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    • 2016
  • S-Nitrosoglutathione reductase (GSNOR) metabolizes S-nitrosoglutathione (GSNO) and has been shown to play important roles in regulating cellular signaling and formulating host defense by modulating intracellular nitric oxide levels. The enzyme has been found in bacterial, yeast, mushroom, plant, and mammalian cells. However, to date, there is still no evidence of its occurrence in filamentous fungi. In this study, we cloned and investigated a GSNOR-like enzyme from the filamentous fungus Aspergillus nidulans. The enzyme occurred in native form as a homodimer and exhibited low thermal stability. GSNO was an ideal substrate for the enzyme. The apparent Km and kcat values were 0.55 mM and 34,100 min-1, respectively. Substrate binding sites and catalytic center amino acid residues based on those from known GSNORs were conserved in this enzyme, and the corresponding roles were verified using site-directed mutagenesis. Therefore, we demonstrated the presence of GSNOR in a filamentous fungus for the first time.

Pharmacokinetic and Bioequivalence Study of Zolpidem Tartate in Healthy Volunteers

  • Park, Jun-Sung;Myung, Ja-Hye;Wang, Hun-Sik;Koo, Ja-Seong;Cho, Won-Kyung;Cha, Kwang-Ho;Park, Hee-Jun;Kim, Min-So;Kim, Jeong-Soo;Hwang, Sung-Joo
    • Journal of Pharmaceutical Investigation
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    • v.41 no.3
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    • pp.191-196
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    • 2011
  • In this study simple and sensitive high performance liquid chromatographic method using a commercially available column, was developed and validated for the determination of zolpidem tartrate in human plasma. The developed method with suitable validation was applied to a bioequivalence study of two different kinds of zolpidem tartrate. Two different formulations containing 10 mg of zolpidem tartate (CAS : 99294-93-6) were compared in 24 healthy male volunteers in order to compare the bioavailability and prove the bioequivalence. The study was performed in an open, single dose randomized, 2-sequence, cross-over design in 24 healthy male volunteers with a one-week washout period. Blood samples for pharmacokinetic profiling were drawn at selected times during 12 h. The mean $AUC_{0-12h}$, $C_{max}$, $T_{max}$ and $T_{1/2}$ were $676.6{\pm}223.4$ $ng{\cdot}h{\cdot}mL^{-1}$, $177.4{\pm}34.2$ $ng{\cdot}mL^{-1}$, and $0.8{\pm}0.4$ and $3.5{\pm}2.1$, respectively, for the test formulations, and $640.7{\pm}186.6$ $ng{\cdot}h{\cdot}mL^{-1}$, $193.0{\pm}64.5$ $ng{\cdot}mL^{-1}$, and $0.9{\pm}0.4$ and $2.7{\pm}0.9$, respectively, for the reference formulation. Both primary target parameters $AUC_{0-12h}$ and $C_{max}$ were log-transformed and tested parametrically by analysis of variance (ANOVA). 90% confidence intervals of $AUC_{0-12h}$ and $C_{max}$ were in the range of acceptable limits of bioequivalence (80-125%). Based on these results, the two formulations of zolpidem tartate are considered to be bioequivalent.

Development of Self-microemulsifying Drug Delivery System for Enhancing the Bioavailability of Atorvastatin

  • Jin, Shun-Ji;Cho, Won-Kyung;Park, Hee-Jun;Cha, Kwang-Ho;Park, Jun-Sung;Koo, Ja-Seong;Wang, Hun-Sik;Kim, Jeong-Soo;Kim, Min-Soo;Hwang, Sung-Joo
    • Journal of Pharmaceutical Investigation
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    • v.41 no.2
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    • pp.103-109
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    • 2011
  • The objective of the study was to prepare self-microeulsifying drug delivery system (SMEDDS) incorporating atorvastatin calcium and evaluate its properties and oral bioavailability. Solubility of atorvastatin in various vehicles was determined. Pseudo-ternary phase diagrams were constructed to identify the good self-emulsification region. The droplet size distributions of the resultant emulsions were determined by dynamic light scattering measurement. The mean droplet size of chosen formulation (20% ethyl oleate, 40% tween-80, 40% Carbitol$^{(R)}$) was $23.4{\pm}1.3$ nm. The SMEDDS incorporating atorvastatin calcium appeared to be associated with better performance in dissolution and pharmacokinetic studies, compared with raw atorvastatin calcium. In dissolution test, the release percentage of atorvastatin from SMEDDS mixture could rapidly reach more than 95% within 3 min. Oral $AUC_{0{\rightarrow}8hr}$ values in SD rats was $1994{\pm}335\;ng{\cdot}hr/mL$, which significantly increased (P<0.05) compared with raw atorvastatin calcium. The SMEDDS formulation was relatively stable when stored at $4^{\circ}C$ during 3 months. Our studies illustrated the potential use of SMEDDS for the delivery of hydrophobic compounds, such as atorvastatin, by the oral route.

Synthesis and applications of graphene electrodes

  • Shin, Dolly;Bae, Su-Kang;Yan, Chao;Kang, Jun-Mo;Ryu, Jae-Chul;Ahn, Jong-Hyun;Hong, Byung-Hee
    • Carbon letters
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    • v.13 no.1
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    • pp.1-16
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    • 2012
  • The near explosion of attention given to graphene has attracted many to its research field. As new studies and findings about graphene synthesis, properties, electronic quality control, and possible applications simultaneous burgeon in the scientific community, it is quite hard to grasp the breadth of graphene history. At this stage, graphene's many fascinating qualities have been amply reported and its potential for various electronic applications are increasing, pulling in ever more newcomers to the field of graphene. Thus it has become important as a community to have an equal understanding of how this material was discovered, why it is stirring up the scientific community and what sort of progress has been made and for what purposes. Since the first discovery, the hype has expediently led to near accomplishment of industrial-sized production of graphene. This review covers the progress and development of synthesis and transfer techniques with an emphasis on the most recent technique of chemical vapor deposition, and explores the potential applications of graphene that are made possible with the improved synthesis and transfer.