• 한국표면공학회지
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• 제39권4호
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• pp.166-172
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• 2006

Metallized Polyimide films are extensively used as base materials in microelectronics, optical and automotive applications. However it is difficult to deposit metals on those because of their structural stabilities. In this work, polyimide films are modified by a wet process with alkalinemetalhydroxide and additives to introduce functional groups. The surface molecular structures of polyimide are investigated using X-ray photoelectron spectroscopy(XPS), fourier transform infrared reflection spectroscopy(FTIR-ATR), atomic force micro-scopic(AFM). XPS spectra and FTIR spectra show that the surface structure of polyimide is converted into potassium polyamate. AFM image and AFM cross-sectional analyses reveal the increased roughness on the modified surface of polyimide films. As a result, it is shown that the adhesion strength between polyimide surface and electroless nickel layer is increased by the nano-anchoring effect.

• Archives of Plastic Surgery
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• 제42권4호
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• pp.469-474
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• 2015

Background Many methods have been proposed for the correction of sunken upper eyelids. These methods include surgical treatments, such as micro-fat, dermofat, or fascia-fat grafts, or the use of alloplastic materials. Here, we present our experience of sunken upper eyelid correction involving the simple addition of anchoring the central fat pad to the medial fat pad during upper blepharoplasty. Methods We performed 74 cases of upper blepharoplasty with sunken upper eyelid correction between October 2013 and September 2014. The lateral portion of the central fat pad was partially dissected to facilitate anchoring. The medial fat pad was gently exposed and then pulled out to facilitate anchoring. After the rotation of the dissected lateral portion of the central fat pad by $180^{\circ}$ to the medial side, it was anchored spreading to the medial fat pad. Photographs taken at 6 months postoperatively were presented to three physicians for objective assessment. Of the 74 patients, 54 patients followed at 6 months postoperatively were included in this retrospective, objective assessment. Results Sunken eyelids were effectively corrected in 51 of the 54 patients, but 3 had minimal effect because preaponeurotic fat pads had been removed during previous upper blepharoplasty. In addition to correcting sunken eyelids, lateral bulging was corrected and a better definition of the lateral portion of upper lid creases was obtained. Conclusions Anchoring the central fat pad to the medial fat pad provides an effective means of correcting sunken upper eyelids during upper blepharoplasty.

• 반도체디스플레이기술학회지
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• 제7권3호
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• pp.41-43
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• 2008

The electro-optical characteristics of the Liquid Crystal on Silicon (hereinafter "LCOS") micro-display on vertically alignment (VA) mode were studied depending on various cell gaps. 5 different cell gaps, such as $1.4{\mu}m,\;1.8{\mu}m,\;2.1{\mu}m,\;2.4{\mu}m$ and $2.8{\mu}m$, were selected. The reflectance-voltage (R-V) characteristics, distributions of reflected light and reflectance were calculated with 3-dimmensional LC code. At the center of cell, the smallest $1.4{\mu}m$ cell gap showed the lowest reflectance and the largest $2.8{\mu}m$ cell gap showed the highest reflectance due to the surface anchoring effect. In case of $2.1{\mu}m$ cell gap, the sum of reflectance overall cell was the highest value. Considering the reflectance and RV curve characteristic, the optimized cell gap was $2.1{\mu}m$.

• 대한전자공학회논문지SD
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• 제46권8호
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• pp.6-11
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• 2009

VA Mode LC를 사용하는 Full-HD급 LCOS 마이크로디스플레이에서 셀 상하 간격의 변화에 따른 전기광학적 특성의 변화에 관하여 3차원 LC code를 이용하여 연구하였다. 5가지의 다른 셀 상하 간격 (1.4 ${\mu}m$, 1.8 ${\mu}m$, 2.1 ${\mu}m$, 2.4 ${\mu}m$ 그리고 2.8 ${\mu}m$)의 변화에 따라 Reflectance-Voltage 특성, 반사광 및 반사율 분포, Optical Fill Factor 그리고 명암비를 비교하였다. Surface Anchoring 효과에 의해 상하 간격이 증가하면서 반사율은 증가하였으나 Optical Fill Factor와 명암비를 고려할 경우, 중간 수준의 간격인 2.1 ${\mu}m$ 의 특성이 가장 우수함을 확인할 수 있었다. 동일한 구조를 갖고 있는 0.7 인치 LCOS 패널을 제작하여 광학적 측정을 해 본 결과 시뮬레이션 결과와 통일함을 확인할 수 있었다.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.244-254
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• 2018

Surface modified poly ${\text\tiny{L}}$-lactic acid (PLLA) samples with hydroxyapatite (HA), heparin and bone morphogenetic protein-2 (BMP-2) mediated by polydopamine (pDA) coating (PLLA/pDA/HA/Hep/BMP-2) were prepared, and their effects on the enhancements of bone formation and osseointegration were evaluated in vitro and in vivo as compared to PLLA, PLLA/pDA/HA, and PLLA/pDA/Hep/BMP-2. The changes in surface chemical compositions, morphologies and wettabilities were observed by X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and water contact angle measurements. Pre-coating of HA particles with pDA provided uniform and homogeneous anchoring of particles to PLLA surface. In addition, the strong ionic interaction between heparin and pDA led PLLA surface readily heparinized for loading of BMP-2. In vitro experiments revealed that the levels of alkaline phosphatase (ALP) activity, calcium deposition, and osteocalcin (OCN) gene expression were higher in MG-63 human osteosarcoma cell lines grown on PLLA/pDA/HA/Hep/BMP-2 than on control PLLA, PLLA/pDA/HA, and PLLA/pDA/Hep/BMP-2. In vivo studies using micro-computed tomography (micro-CT) also showed that PLLA/pDA/HA/Hep/BMP-2 screw exhibited greatest value of bone volume (BV) and bone volume/tissue volume (BV/TV) among samples. Histological evaluations with H&E and Von Kossa staining demonstrated that a combination of HA and BMP-2 contributed to the strong osseointegration.

• 한국표면공학회지
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• 제45권1호
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• pp.1-7
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• 2012

Multi-walled carbon nanotube (MWCNT) aluminum composite powders were deposited to form coatings using a high velocity oxygen fuel (HVOF) spraying process. High thermal energy and contact with atmospheric oxygen were supplied as the MWCNT aluminum composite particles were exposed to a gas flow field at high temperature (${\sim}3.0{\times}10^3$ K) during HVOF spraying. As a result, the particles underwent full or partial melting and rapid solidification due to the high thermal energy, and the exposure to oxygen induced the interfacial reaction of MWCNTs within the particle. The electrical and mechanical properties of MWCNT aluminum composite coatings were evaluated based on microstructure analysis. Electrical resistivity, elastic modulus, and micro-hardness, of the MWCNT aluminum composite coatings were higher than those of pure aluminum coating. The contribution of MWCNTs to the aluminum matrix can be attributed to their high electrical conductivity, dispersion hardening and anchoring effects. The relationship among the properties and the interaction of the MWCNTs with the aluminum matrix is discussed.

• Molecules and Cells
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• 제23권2호
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• pp.228-238
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• 2007

Since molecular structure of hnRNP is not available in foreseeable future, it is best to construct a working model for hnRNP structure. A geometric problem, assembly of $700{\pm}20$ nucleotides with 48 proteins, is visualized by a frame work in which all the proteins participate in primary binding, followed by secondary, tertiary and quaternary binding with neighboring proteins without additional import. Thus, 40S hnRNP contains crown-like secondary structure (48 stemloops) and appearance of 6 petal (octamers) rose-like architectures. The proteins are wrapped by RNA. Co-transcriptional folding for RNP fibril of FMR1 gene can produce 2,571 stem-loops with frequency of 1 stem-loop/15.3 nucleotides and 53 40S hnRNP beaded structure. By spliceosome driven reactions, there occurs removal of 16 separate lariated RNPs, joining 17 separate beaded exonic structures and anchoring EJC on each exon junction. Skipping exon 12 has 5'GU, 3'AG and very compact folding pattern with frequency of 1 stem-loop per 12 nucleotides in short exon length (63 nucleotides). 5' end of exon 12 contains SS (Splicing Silencer) element of UAGGU. In exons 10, 15 and 17 where both regular and alternative splice sites exist, SS (hnRNP A1 binding site) is observed at the regular splicing site. End products are mature FMR-1 mRNP, 4 species of Pri-microRNAs derived from introns 7,9,15 and 3'UTR of exon17, respectively. There may also be some other regulatory RNAs containing ALU/Line elements as well.