• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.187-187
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• 2012

In this report, the plasmonic nanopores of less than 5 nm diameter were fabricated on the apex of the pyramidal cavity array. The metallic pyramidal pit cavity can also utilized as the plasmonic bioreactor, and the fabricated Au or Al metallic nanopore can provide the controllable translocation speed down using the plasmonic optical force. Initially, the SiO2 nanopore on the pyramidal pit cavity were fabricated using conventional microfabrication techniques. Then, the metallic thin film was sputter-deposited, followed by surface modification of the nanometer thick membrane using FESEM, TEM and EPMA. The huge electron intensity of FESEM with ~microsecond scan speed can provide the rapid solid phase surface transformation. However, the moderate electron beam intensity from the normal TEM without high speed scanning can only provide the liquid phase surface modification. After metal deposition, the 100 nm diameter aperture using FIB beam drilling was obtained in order to obtain the uniform nano-aperture. Then, the nanometer size aperture was reduced down to ~50 nm using electron beam surface modification using high speed scanning FESEM. The followed EPMA electron beam exposure without high speed scanning presents the reduction of the nanosize aperture down to 10 nm. During these processes, the widening or the shrinking of the nanometer pore was observed depending upon the electron beam intensity. Finally, using 200 keV TEM, the diameter of the nanopore was successively down from 10 nm down to 1.5 nm.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.11
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• pp.1-7
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• 2008

In this work, a two dimensional, self-consistent Poisson-$Schr{\ddot{o}}dinger$ solver has been implemented to study C-V characteristics in nanometer scale MuGFETs with considering quantum effects. The quantum-mechanical effects on gate-channel capacitance for different device dimension and gate configurations of nanometer scale MuGFETs have been analyzed. It has been found that 4he gate-channel capacitance per unit gate area is increased as the device dimension decreases. For different gate configurations, the gate-channel capacitance is decreased with increase of effective gate number. Those resu1ts have been explained by the distribution profile of electron concentration in the silicon surface and inversion capacitance. The length of inversion-layer centroid has been calculated from inversion capacitance with device dimension and gate configurations.

• Transactions of the Society of Information Storage Systems
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• v.1 no.2
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• pp.127-131
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• 2005

We report a nanometer scale mark formation using a $PtO_x$ thin film or a TbFeCo rare-earth transition metal film and the mechanism. The multi-layer samples($ZnS-SiO_2/PtOx/ZNS-SiO_2,\;ZnS-SiO_2/TbFeCo/ZnS-SiO_2$) were prepared with a magnetron sputtering method on a polycarbonate or a glass substrate. By laser irradiation of approximately a few nanoseconds, nanometer scale marks were fabricated. During the fabrication process, the thin films were thermally reacted or inter-diffused during the laser irradiation. 75 nm bubble marks in the PtOx multi-layer sample by an approximately 4-ns laser irradiation. Inside the bubble mark, Pt particles with a few nanometer sizes are distributed. The $50{\sim}100$ nm bubble marks in the TbFeCo multi-layer sample by a few nanosecond laser irradiations. We will report the detail structure of the samples, the bubble mark formation process and the mechanism.

• Journal of Periodontal and Implant Science
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• v.47 no.2
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• pp.116-131
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• 2017

Purpose: The entry of bacteria or harmful substances through the epithelial seal of human gingival keratinocytes (HGKs) in the junctional epithelium (JE) is blocked by specialized intercellular junctions such as E-cadherin junctions (ECJs). However, the influence of roughened substrates, which may occur due to apical migration of the JE, root planing, or peri-implantitis, on the development of the ECJs of HGKs remains largely unknown. Methods: HGKs were cultured on substrates with varying levels of roughness, which were prepared by rubbing hydrophobic polystyrene dishes with silicon carbide papers. The activity of c-Jun N-terminal kinase (JNK) was inhibited with SP600125 or by transfection with JNK short hairpin RNA. The development of intercellular junctions was analyzed using scanning electron microscopy or confocal laser scanning microscopy after immunohistochemical staining of the cells for E-cadherin. The expression level of phospho-JNK was assessed by immunoblotting. Results: HGKs developed tight intercellular junctions devoid of wide intercellular gaps on smooth substrates and on rough substrates with low-nanometer dimensions (average roughness $[Ra]=121.3{\pm}13.4nm$), although the ECJs of HGKs on rough substrates with low-nanometer dimensions developed later than those of HGKs on smooth substrates. In contrast, HGKs developed short intercellular junctions with wide intercellular gaps on rough substrates with mid- or high-nanometer dimensions ($Ra=505.3{\pm}115.3nm$, $867.0{\pm}168.6nm$). Notably, the stability of the ECJs was low on the rough substrates, as demonstrated by the rapid destruction of the cell junction following calcium depletion. Inhibition of JNK activity promoted ECJ development in HGKs. JNK was closely associated with cortical actin in the regulation of ECJs in HGKs. Conclusions: These results indicate that on rough substrates with nanometer dimensions, the ECJs of HGKs develop slowly or defectively, and that this effect can be reversed by inhibiting JNK.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.155-156
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• 2007

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.357-357
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• 2003

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.64-64
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• 2003

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.97-97
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• 2003

Chemists must take into consideration more factors to formulate with inorganic sunscreens than many other active ingredients including organic sunscreens. Because the UV radiation attenuation grade particles of Titanium Dioxide and Zinc Oxide are in the nanometer range, the state of their dispersion in the product film on the skin governs their efficacy and aesthetics.(omitted)

• Proceedings of the Korean Ceranic Society Conference
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• 2004.04b
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• pp.50.1-50.1
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• 2004

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.493-494
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• 2009