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Your search keyword '"Oh, Sang-Hyun"' showing total 310 results
Start Over Author "Oh, Sang-Hyun" Publication Type Academic Journals
310 results on '"Oh, Sang-Hyun"'

22. Continuity of Monolayer-Bilayer Junctions for Localization of Lipid Raft Microdomains in Model Membranes.

Author

Ryu, Yong-Sang, Wittenberg, Nathan J, Suh, Jeng-Hun, Lee, Sang-Wook, Sohn, Youngjoo, Oh, Sang-Hyun, Parikh, Atul N, and Lee, Sin-Doo

Subjects
Membrane Microdomains, Cholesterol, Cholera Toxin, G(M1) Ganglioside, Sphingomyelins, Lipid Bilayers, Receptors, Cell Surface, Protein Binding, Models, Biological, Hydrophobic and Hydrophilic Interactions, Models, Biological, Receptors, Cell Surface
Abstract

We show that the selective localization of cholesterol-rich domains and associated ganglioside receptors prefer to occur in the monolayer across continuous monolayer-bilayer junctions (MBJs) in supported lipid membranes. For the MBJs, glass substrates were patterned with poly(dimethylsiloxane) (PDMS) oligomers by thermally-assisted contact printing, leaving behind 3 nm-thick PDMS patterns. The hydrophobicity of the transferred PDMS patterns was precisely tuned by the stamping temperature. Lipid monolayers were formed on the PDMS patterned surface while lipid bilayers were on the bare glass surface. Due to the continuity of the lipid membranes over the MBJs, essentially free diffusion of lipids was allowed between the monolayer on the PDMS surface and the upper leaflet of the bilayer on the glass substrate. The preferential localization of sphingomyelin, ganglioside GM1 and cholesterol in the monolayer region enabled to develop raft microdomains through coarsening of nanorafts. Our methodology provides a simple and effective scheme of non-disruptive manipulation of the chemical landscape associated with lipid phase separations, which leads to more sophisticated applications in biosensors and as cell culture substrates.

Published
2016

23. Reconstituting ring-rafts in bud-mimicking topography of model membranes.

Author

Ryu, Yong-Sang, Lee, In-Ho, Suh, Jeng-Hun, Park, Seung Chul, Oh, Soojung, Jordan, Luke R, Wittenberg, Nathan J, Oh, Sang-Hyun, Jeon, Noo Li, Lee, Byoungho, Parikh, Atul N, and Lee, Sin-Doo

Subjects
Cell Membrane, Membrane Microdomains, Dimethylpolysiloxanes, Cholesterol, Sphingomyelins, Membrane Lipids, Lipid Bilayers, Phosphatidylcholines, Imaging, Three-Dimensional, Imaging, Three-Dimensional
Abstract

During vesicular trafficking and release of enveloped viruses, the budding and fission processes dynamically remodel the donor cell membrane in a protein- or a lipid-mediated manner. In all cases, in addition to the generation or relief of the curvature stress, the buds recruit specific lipids and proteins from the donor membrane through restricted diffusion for the development of a ring-type raft domain of closed topology. Here, by reconstituting the bud topography in a model membrane, we demonstrate the preferential localization of cholesterol- and sphingomyelin-enriched microdomains in the collar band of the bud-neck interfaced with the donor membrane. The geometrical approach to the recapitulation of the dynamic membrane reorganization, resulting from the local radii of curvatures from nanometre-to-micrometre scales, offers important clues for understanding the active roles of the bud topography in the sorting and migration machinery of key signalling proteins involved in membrane budding.

Published
2014

24. Bandgap engineering of two-dimensional semiconductor materials

Author

Chaves, A., Azadani, J. G., Alsalman, Hussain, da Costa, D. R., Frisenda, R., Chaves, A. J., Song, Seung Hyun, Kim, Y. D., He, Daowei, Zhou, Jiadong, Castellanos-Gomez, A., Peeters, F. M., Liu, Zheng, Hinkle, C. L., Oh, Sang-Hyun, Ye, Peide D., Koester, Steven J., Lee, Young Hee, Avouris, Ph., Wang, Xinran, and Low, Tony

Published
2020
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26. Nanoscale tweezers for single-cell biopsies

Author

Nadappuram, Binoy Paulose, Cadinu, Paolo, Barik, Avijit, Ainscough, Alexander J., Devine, Michael J., Kang, Minkyung, Gonzalez-Garcia, Jorge, Kittler, Josef T., Willison, Keith R., Vilar, Ramon, Actis, Paolo, Wojciak-Stothard, Beata, Oh, Sang-Hyun, Ivanov, Aleksandar P., and Edel, Joshua B.

Published
2019
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33. Promises and challenges of nanoplasmonic devices for refractometric biosensing

Author

Dahlin Andreas B., Wittenberg Nathan J., Höök Fredrik, and Oh Sang-Hyun

Subjects
optical biosensors, refractometric sensors, surface plasmon resonance, plasmonics, figure of merit, single molecule detection, enzyme-linked biosensing, site-specific chemistry, supported lipid bilayer, pore-spanning lipid membrane, nanoparticle, nanohole, optofluidics, Physics, QC1-999
Abstract

Optical biosensors based on surface plasmon resonance (SPR) in metallic thin films are currently standard tools for measuring molecular binding kinetics and affinities – an important task for biophysical studies and pharmaceutical development. Motivated by recent progress in the design and fabrication of metallic nanostructures, such as nanoparticles or nanoholes of various shapes, researchers have been pursuing a new generation of biosensors harnessing tailored plasmonic effects in these engineered nanostructures. Nanoplasmonic devices, while demanding nanofabrication, offer tunability with respect to sensor dimension and physical properties, thereby enabling novel biological interfacing opportunities and extreme miniaturization. Here we provide an integrated overview of refractometric biosensing with nanoplasmonic devices and highlight some recent examples of nanoplasmonic sensors capable of unique functions that are difficult to accomplish with conventional SPR. For example, since the local field strength and spatial distribution can be readily tuned by varying the shape and arrangement of nanostructures, biomolecular interactions can be controlled to occur in regions of high field strength. This may improve signal-to-noise and also enable sensing a small number of molecules. Furthermore, the nanoscale plasmonic sensor elements may, in combination with nanofabrication and materials-selective surface-modifications, make it possible to merge affinity biosensing with nanofluidic liquid handling.

Published
2013
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42. Plasmonic nanoholes in a multichannel microarray format for parallel kinetic assays and differential sensing

Author

Im, Hyungsoon, Lesuffleur, Antoine, Lindquist, Nathan C., and Oh, Sang-Hyun

Subjects
Plasmons (Physics) -- Properties, Nanotechnology -- Research, Microfluidics -- Research, Fluidic devices -- Properties, Molecular dynamics -- Research, Resonance -- Research, Protein microarrays -- Properties, Biosensors -- Design and construction, Biosensors -- Properties, Chemistry
Abstract

We present nanohole arrays in a gold film integrated with a six-channel microfluidic chip for parallel measurements of molecular binding kinetics. Surface plasmon resonance effects in the nanohole arrays enable real-time, label-free measurements of molecular binding events in each channel, while adjacent negative reference channels can record measurement artifacts such as bulk solution index changes, temperature variations, or changing light absorption in the liquid. With the use of this platform, streptavidin--biotin specific binding kinetics are measured at various concentrations with negative controls. A high-density microarray of 252 biosensing pixels is also demonstrated with a packing density of 106 sensing elements/[cm.sup.2], which can potentially be coupled with a massively parallel array of microfluidic channels for protein microarray applications.

Published
2009

43. Attenuation mechanism effect on filter shape in channelized dynamic spectral equalizers

Author

Oh, Sang-Hyun and Marom, Dan M.

Subjects
Optics, Astronomy, Physics
Abstract

Free-space-based channelized dynamic spectral equalizers are theoretically investigated by solving the temporal-frequency-dependent power-coupling integral for commonly used active device technologies: liquid-crystal modulators, tilting micromirror arrays, and deformable gratings. Channel-filter characteristics, such as bandwidth and interchannel transition, are found to depend on the different attenuation mechanisms provided by the active devices. Such information is required for choosing the proper device parameters in designing channel equalizers and similar free-space spatially dispersed subsystems. OCIS codes: 060.2340, 070.6110, 230.6120, 010.1080, 120.2440.

Published
2004

44. Monolithic fringe-field-activated crystalline silicon tilting-mirror devices

Author

Greywall, Dennis S., Pai, Chien-Shing, Oh, Sang-Hyun, Chang, Chorng-Ping, Marom, Dan M., Busch, Paul A., Cirelli, Raymond A., Taylor, Ashley J., Klemens, Fred P., Sorsch, Thomas W., Bower, John Eric, Lai, Warren Y.-C., and Soh, Hyongsok T.

Subjects
Microelectromechanical systems -- Research, Engineering and manufacturing industries, Science and technology
Abstract

A new approach is presented for fabricating monolithic crystalline silicon tilting-mirror microoptoelectromechanical systems (MOEMS) devices. The activation electrodes, etched from a thick silicon layer deposited over insulating oxide onto the top surface of a silicon-on-insulator (SOI) wafer, are displaced from the mirrors and interact with these tilting elements via electrostatic fringing fields. In contrast to the more usual parallel-plate activation, the rotation angle saturates at high voltages. This paper discusses concept, design, and processing, and also compares modeling and measured performance of a specific 9[degrees] tilt range device array. [977] Index Terms--MEMS, MOEMS, micromachined structures, optical telecommunications.

Published
2003

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