Research Center for Applied science

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Research Center for Applied science

science, Taiwan
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Patra B.,Research Center for Applied science | Patra B.,National Yang Ming University | Peng C.-C.,Research Center for Applied science | Liao W.-H.,Research Center for Applied science | And 4 more authors.
Scientific Reports | Year: 2016

Three-dimensional (3D) tumor spheroid possesses great potential as an in vitro model to improve predictive capacity for pre-clinical drug testing. In this paper, we combine advantages of flow cytometry and microfluidics to perform drug testing and analysis on a large number (5000) of uniform sized tumor spheroids. The spheroids are formed, cultured, and treated with drugs inside a microfluidic device. The spheroids can then be harvested from the device without tedious operation. Due to the ample cell numbers, the spheroids can be dissociated into single cells for flow cytometry analysis. Flow cytometry provides statistical information in single cell resolution that makes it feasible to better investigate drug functions on the cells in more in vivo-like 3D formation. In the experiments, human hepatocellular carcinoma cells (HepG2) are exploited to form tumor spheroids within the microfluidic device, and three anti-cancer drugs: Cisplatin, Resveratrol, and Tirapazamine (TPZ), and their combinations are tested on the tumor spheroids with two different sizes. The experimental results suggest the cell culture format (2D monolayer vs. 3D spheroid) and spheroid size play critical roles in drug responses, and also demonstrate the advantages of bridging the two techniques in pharmaceutical drug screening applications.

Wei H.-Y.,National Taiwan University | Huang J.-H.,Academia Sinica, Taiwan | Ho K.-C.,National Taiwan University | Ho K.-C.,National Chiao Tung University | And 2 more authors.
ACS Applied Materials and Interfaces | Year: 2010

We have developed polymer solar cells featuring a buffer layer of polythiophene (PT) sandwiched between the active layer and the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layer. We attribute the improvement in power conversion efficiency of these polymer solar cells, relative to that of those based on poly(3-hexylthiophene):[6,6]-phenyl- C 61-butyric acid methyl ester (P3HT:PCBM), to a reduction in the degree of carrier recombination at the junction interface. Because the conductivity and the energy level of PT can be tuned simply by applying a bias to it in an electrolytic solution, we also investigated the effect of the energy level on the devices' performances. The power conversion efficiency of a solar cell containing a PT buffer layer reached 4.18% under AM 1.5 G irradiation (100 mW/cm 2). © 2010 American Chemical Society.

Chen J.-B.,National Taiwan University | Chern T.-R.,Research Center for Applied science | Lin J.-H.,Research Center for Applied science | Lin J.-H.,Academia Sinica, Taiwan | And 2 more authors.
Journal of Medicinal Chemistry | Year: 2013

A series of dual-action compounds were designed to target histone deacetylase (HDAC) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) by having a hydroxamate group essential for chelation with the zinc ion in the active site of HDAC and the key structural elements of statin for binding with both proteins. In our study, the statin hydroxamic acids prepared by a fused strategy are most promising in cancer treatments. These compounds showed potent inhibitory activities against HDACs and HMGR with IC50 values in the nanomolar range. These compounds also effectively reduced the HMGR activity as well as promoted the acetylations of histone and tubulin in cancer cells, but were not toxic to normal cells. © 2013 American Chemical Society.

Chen M.,Research Center for Applied science | Li Y.-J.,National Chiao Tung University | Cheng Y.-J.,Research Center for Applied science | Cheng Y.-J.,National Chiao Tung University | And 3 more authors.
Optics Express | Year: 2014

This work investigates the resonant modes of a 12-fold symmetric defect free photonic quasicrystal (PQC) nanorod array using finite difference time domain (FDTD) simulation. Localized modes can exist in PQC without introducing defects due to the lack of translational symmetry. The resonant modes of the unit cell PQC and the one time expanded PQC from unit cell are systematically examined. The resonant spectrum is that of a single rod modified by the interaction among PQC nanorods. The mode confinement is contributed by guided resonance and destructive interference scattering. The self-scaling similarity of resonant spectrum and mode profile are also investigated.©2014 Optical Society of America.

Huang J.-H.,Research Center for Applied science | Ibrahem M.A.,Research Center for Applied science | Ibrahem M.A.,University of Taipei | Chu C.-W.,Research Center for Applied science | Chu C.-W.,National Chiao Tung University
Progress in Photovoltaics: Research and Applications | Year: 2015

In this study, an air-stable bulk heterojunction organic solar cell demonstrated by utilization of titanium oxide (TiO2) nanoparticles as a hole blocking layer was prepared through high-energy grinding method. The large clumps of the anatase TiO2 underwent deaggregation to form a stable dispersed solution during the grinding process. The resultant suspension can form a uniform and smooth TiO2 film through spin coating on various substrates. Because of substantial oxygen and water protection effect of TiO2 thin film, the bulk heterojunction solar cells exhibit a significant long-term stability. It is also found that the cell performance can be promoted dramatically after ultraviolet activation. The mechanism responsible for the enhanced cell efficiency was also investigated. This solution-based method does not require surfactants, thus preserving the intrinsic electronic and optical properties of TiO2 that makes these proposed buffer layers quite attractive for next-generation flexible devices appealing high conductivity and transparency. Copyright © 2014 John Wiley & Sons, Ltd.

Chen K.-J.,National Chiao Tung University | Chen H.-C.,National Chiao Tung University | Shih M.-H.,National Chiao Tung University | Shih M.-H.,Research Center for Applied science | And 5 more authors.
Journal of Lightwave Technology | Year: 2012

This study investigates the effect of temperature on CdSe/ZnS quantum dots (QDs) in GaN-based light-emitting diodes (LEDs) using the phosphor conversion efficiency (PCE) and LED junction temperature. In our simulation, the blue chip and CdSe/ZnS QDs temperature are similar because of their minimal thickness. Furthermore, to verify the effect of temperature on CdSe/ZnS QDs, we use continuous wave and pulsed current sources to measure the relationship between the temperature and relative PCE. Higher junction temperatures are observed with greater CdSe/ZnS QD volume in LEDs. This is attributed to the thermal conduction and nonradiative energy between CdSe/ZnS QDs and blue chip. Therefore, if thermal management is improved, CdSe/ZnS QDs are expected to be used as color converting material in LEDs. © 2012 IEEE.

See K.-M.,National Tsing Hua University | Lin F.-C.,National Tsing Hua University | Huang J.-S.,National Tsing Hua University | Huang J.-S.,Institute of Photonic Technology | Huang J.-S.,Research Center for Applied science
Nanoscale | Year: 2017

We present a two-dimensional plasmonic Doppler grating (PDG) for broadband and azimuthal angle-resolved nanophotonic applications. The PDG consists of a set of non-concentric circular rings mimicking the wavefronts of a moving point source that exhibits the Doppler effect and thereby offers a continuous azimuthal angle-dependent lattice momentum for photon-plasmon coupling. The center and span of the working frequency window are fully designable for optimal performance in specific applications. We detail the design, fabrication and optical characterization of the PDG. The design of the Doppler grating provides a general platform for in-plane angle-resolved nanophotonic applications. © 2017 The Royal Society of Chemistry.

Taloni A.,CNR Institute for Energetics and Interphases | Yeh J.-W.,Academia Sinica, Taiwan | Chou C.-F.,Academia Sinica, Taiwan | Chou C.-F.,Research Center for Applied science
Macromolecules | Year: 2013

We provide a scaling framework describing the different regimes attained by a slit-confined polymer, undergoing an external pulling force f el,slit. Linear and nonlinear force-extension relations are discussed in the limit of small and large elongations, resorting to the notion of self-avoiding pancakes. The crossover to a channellike behavior allows to explain the scaling of fel,slit as a function of the confinement h observed in recent tug-of-war experiments. The theoretical analysis provides also a qualitative explanation of DNA relaxation and coil-stretch transition experiments performed in nanoslits. © 2013 American Chemical Society.

PubMed | Research Center for Applied science and National Yang Ming University
Type: | Journal: Journal of visualized experiments : JoVE | Year: 2016

The behavior of directional cell migration under a direct current electric-field (dcEF) is referred to as electrotaxis. The significant role of physiological dcEF in guiding cell movement during embryo development, cell differentiation, and wound healing has been demonstrated in many studies. By applying microfluidic chips to an electrotaxis assay, the investigation process is shortened and experimental errors are minimized. In recent years, microfluidic devices made of polymeric substances (e.g., polymethylmethacrylate, PMMA, or acrylic) or polydimethylsiloxane (PDMS) have been widely used in studying the responses of cells to electrical stimulation. However, unlike the numerous steps required to fabricate a PDMS device, the simple and rapid construction of the acrylic microuidic chip makes it suitable for both device prototyping and production. Yet none of the reported devices facilitate the efficient study of the simultaneous chemical and dcEF effects on cells. In this report, we describe our design and fabrication of an acrylic-based multichannel dual-electric-field (MDF) chip to investigate the concurrent effect of chemical and electrical stimulation on lung cancer cells. The MDF chip provides eight combinations of electrical/chemical stimulations in a single test. The chip not only greatly shortens the required experimental time but also increases accuracy in electrotaxis studies.

Dou K.P.,Research Center for Applied science | Tai J.-S.,Research Center for Applied science | Kaun C.-C.,Research Center for Applied science | Kaun C.-C.,National Tsing Hua University
Journal of Physical Chemistry C | Year: 2015

Using first-principles calculations based on density functional theory and nonequilibrium Green's function formalism, we study the electron transport through a magnesium porphine molecule adsorbed on an ultrathin NaCl bilayer. The conductance of the tip-vacuum-molecule-NaCl-metal junction depends on the orientation of the molecule on the insulating surface and the tip position above the molecule, which is mediated largely by the molecular pz orbital. The movement of molecule results in a perturbation to the spatial extension of these orbitals, leading to different conductions. © 2015 American Chemical Society.

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