Browsing by Author "Kuo, Kuan-Ting"

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A Multifunctional Nanodevice Capable of Imaging, Magnetically Controlling, and In Situ Monitoring Drug Release
(2009-11-09)
Hu, Shang-Hsiu
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Kuo, Kuan-Ting
;
Tung, Wei-Lin
;
Liu, Dean-Mo
;
Chen, San-Yuan
The multifunctional nanodevice described here integrates nanoscaled imaging, targeting, and controlled drug delivery, as well as the capability to monitor, in situ, the amount of drug released from the nanodevice with single-cell resolution. The nanodevice is composed of a polymer core/single-crystal iron oxide shell nanostructure bonded to a quantum dot. It shows outstanding release and retention characteristics via an external on/off manipulation of a high-frequency magnetic field. Upon magnetic stimulation, the single-crystal iron oxide shell demonstrates formation of nanometer-sized polycrystal domains of varying orientation. This allows a variation between retention and slow release of the drug. Further stimulation causes permanent rupturing of the shell, causing release of the drug in a burst-like manner. The quantum dot bonded to the nanodevice provides optical information for in situ monitoring of the drug release through use of a magnetic field. Remote control drug release from the nanodevice in a cancerous cell line (HeLa) was successfully accomplished using the same induction scenario. When nanodevices equipped with quantum dots are taken into cancerous cells, they are able to provide real-time drug dose information through a corresponding variation in emission spectrum. The nanodevice designed in this study has achieved its potential as a cell-based drug-delivery system for therapeutic applications.
BaMgAl10O17 : Eu blue phosphors with MgO coating and microwave irradiation
(2008-02-01)
Kuo, Kuan-Ting
;
Lee, Shu-Ping
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Chen, San-Yuan
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Cheng, Bing-Ming
;
Lu, Hsiao-Chi
Europium-activated barium magnesium aluminate (BaMgAl10O17:Eu (BAM)) phosphor particles were modified by surface coating with MgO using a polyol method. The photoluminescence (PL) properties of the MgO-coated BAM phosphors showed slightly improved blue-emission intensity compared to the unmodified ones, and reached a stronger peak intensity with 5.25% MgO coating, under vacuum ultraviolet (VUV) 147 nm excitation. Upon microwave irradiation on the MgO-coated BAM phosphors, the PL properties of the MgO-coated phosphors exhibited a much enhanced relative PL ratio, and a maximum relative PL ratio can be achieved when as high as 10.5% MgO was deposited on the phosphor surface. However, for mechanically ground phosphor powder, it was found that although the intensity of the MgO-coated BAM turned stronger with increasing MgO concentration under microwave irradiation, the purity of the resulting luminescence was slightly disrupted by the presence of a new peak near 470 nm, corresponding to BaMg3Al14O25 compound. (C) 2007 Elsevier Ltd. All rights reserved.
Core-shell CuInS(2)/ZnS quantum dots assembled on short ZnO nanowires with enhanced photo-conversion efficiency
(2009-01-01)
Kuo, Kuan-Ting
;
Liu, Dean-Mo
;
Chen, San-Yuan
;
Lin, Chin-Ching
;
材料科學與工程學系
A novel quantum-dot-based solar cell assembly consisting of core-shell Zn-doped CuInS(2)@ZnS (Zn-CIS@ZnS) quantum dots associated with short ZnO (5 mu m in length) nanowires was developed and systematically investigated in terms of its nanostructure and optical properties, associated with corresponding solar cell parameters, i.e., V(OC), J(SC), fill factor (FF). In this investigation, the photo-conversion efficiency of the Zn-CIS-based solar cells without the presence of the ZnS shell can be readily tuned by controlling the Zn/Cu ratio. Furthermore, the efficiency was significantly improved upon the deposition of a thin ZnS shell on these Zn-CIS QDs, where a significant enhancement in short-circuit current density (J(SC)) by 88% was observed because the ZnS coating is able to effectively eliminate excited electron recombination and enhance the charge transfer efficiency from Zn-CIS QDs to ZnO nanowires. Power-conversion efficiency as high as 0.71% can be attained, which is improved more than 2-3 times compared with that without ZnS coating. Such a unique nanoarchitecture through coupling with both core-shell QDs and short ZnO nanowires suggests a promising design for a quantum dot-based solar cell with considerably improved power-conversion efficiency.
Core-shell CuInS2/ZnS quantum dots assembled on short ZnO nanowires with enhanced photo-conversion efficiency
(2009-01-01)
Kuo, Kuan-Ting
;
Liu, Dean-Mo
;
Chen, San-Yuan
;
Lin, Chin-Ching
;
材料科學與工程學系
A novel quantum-dot-based solar cell assembly consisting of core-shell Zn-doped CuInS2@ZnS (Zn-CIS@ZnS) quantum dots associated with short ZnO (5 mu m in length) nanowires was developed and systematically investigated in terms of its nanostructure and optical properties, associated with corresponding solar cell parameters, i.e., V-OC, J(SC), fill factor (FF). In this investigation, the photo-conversion efficiency of the Zn-CIS-based solar cells without the presence of the ZnS shell can be readily tuned by controlling the Zn/Cu ratio. Furthermore, the efficiency was significantly improved upon the deposition of a thin ZnS shell on these Zn-CIS QDs, where a significant enhancement in short-circuit current density (J(SC)) by 88% was observed because the ZnS coating is able to effectively eliminate excited electron recombination and enhance the charge transfer efficiency from Zn-CIS QDs to ZnO nanowires. Power-conversion efficiency as high as 0.71% can be attained, which is improved more than 2-3 times compared with that without ZnS coating. Such a unique nanoarchitecture through coupling with both core-shell QDs and short ZnO nanowires suggests a promising design for a quantum dot-based solar cell with considerably improved power-conversion efficiency.
Effect of microwave irradiation on surface characteristics and luminescent properties of BaMgAl10O17 : Eu blue phosphor
(2008-02-01)
Kuo, Kuan-Ting
;
Lee, Shu-Ping
;
Chen, San-Yuan
;
Cheng, Bing-Ming
;
Lu, Hsiao-Chi
BaMgAl10O17:Eu (BAM) has been an excellent blue-emitting phosphor due to its outstanding luminescence efficiency and purity for plasma display panels. An attempt of employing microwave irradiation to modify the surface properties including morphology and crystallinity of BAM powder was performed in this work. X-ray powder diffraction (XRD) analysis and scanning electron microscopy (SEM) images show that the blue-emitting phosphors after microwave irradiation treatment exhibit better crystallinity and smoother surface. Furthermore, the vacuum ultraviolet photoluminescence spectra show that the luminescent intensity of BAM phosphors can be effectively enhanced by a factor of six times under microwave irradiation treatment. The enhanced luminescent properties can be closely related to the surface modification and reduced defects of the BAM blue-emitting phosphors. (C) 2007 Elsevier Ltd. All rights reserved.
Magnetically-induced synthesis of highly-crystalline ternary chalcopyrite nanocrystals under ambient conditions
(2010)
Kuo, Kuan-Ting
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Hu, Shang-Hsiu
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Liu, Dean-Mo
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Chen, San-Yuan
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材料科學與工程學系
We report a novel and facile method to synthesize phase pure, chemically homogeneous, and highly crystalline CuInS(2), an important element for optoelectronics, optics, and solar energy applications. This ternary semiconductor compound is grown by magnetic Zn doping under high-frequency magnetic induction at ambient conditions. The magnetic doping gives superparamagnetic heating of the resulting nanocrystals via magnetic induction, causing an accelerating growth rate of the doped CuInS(2) under ambient conditions of 2-3 orders of magnitude faster than conventional autoclave synthesis. Shape evolution of the Zn doped CuInS(2) nanocrystals from initially spherical, to pyramidal, cubic, and finally to a bar geometry, was detected as a function of time of exposure to magnetic induction. These newly-synthesized nanocrystals demonstrated considerably improved optical emission properties compared to those prepared via conventional autoclave methods. Nanostructural development of the nanocrystals was well characterized and a mechanism of crystal growth was proposed.
SPECTRO-TEMPORAL NEURAL FACTORIZATION FOR SPEECH DEREVERBERATION
(2018-01-01)
Chien, Jen-Tzung
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Kuo, Kuan-Ting
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電機工程學系
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Department of Electrical and Computer Engineering
This study presents a spectro-temporal neural factorization (STNF) for speech dereverberation. Traditionally, a contextual window of spectro-temporal reverberant speech was unfolded into a one-way vector which was fed into a neural network to estimate the spectra of source speech at each time frame. Model parameters were trained by using the vectorized error backpropagation algorithm. System performance is constrained because contextual correlations and common factors in frequency and time horizons are disregarded. To compensate this weakness, a spectro-temporal factorization is incorporated to preserve the structural information in neural network training based on bi-factorized error backpropagation where the spectral and temporal factor matrices are estimated. Affine transformation in one-way neural network is generalized to the bilinear decomposition in bi-factorized neural network. The spectro-temporal features are extracted and forwarded to fully-connected layers for regression outputs. Such a STNF is further improved by merging with long short-term memory layer to capture the temporal features. Experiments results on 2014 REVERB Challenge demonstrate the meaningfulness of the factorized features and the merit of integrating these features for speech dereverberation.
Study on luminous phosphor with improved luminous efficiency for plasma planar backlight
(2005)
Lin, Chin-Ching
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Lee, Shu-Ping
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Kuo, Kuan-Ting
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Chen, San-Yuan
;
Hsieh, Hank
Highly luminescent efficiency white-light phosphors have been successfully produced by microwave irradiation treatment. The SEM image and XRD analysis reveal that the surface morphology of the white-light phosphors can be notably modified by microwave irradiation from sheet-like into spherical shapes and exhibit with better crystalline property. The VUV PL spectra show that the microwave irradiation treatment can effectively enhance the luminescent efficiency by a factor of 1.5 times for intensity in comparison with that without microwave treatment. The improvement in all visible emission can he related to the modified surface morphology and increased crystalline properties of the white-light phosphors. These results demonstrate that such a simple approach can provide for the fabrication of highly luminescent efficiency phosphors for the optoelectronic devices.
Synthesis and characterization of highly luminescent CuInS(2) and CuInS(2)/ZnS (core/shell) nanocrystals
(2008-12-01)
Kuo, Kuan-Ting
;
Chen, San-Yuan
;
Cheng, Bing-Ming
;
Lin, Chin-Ching
;
材料科學與工程學系
High-quality CuInS(2)/ZnS (core-shell) nanocrystals (NCs) were synthesized via a colloidal solvent process and characterized for their optical properties by UV-vis, room temperature solution photoluminescence (PL) spectroscopy, and further obtained powders were characterized by X-ray microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and dynamic light scattering (DLS). diffraction (XRD), transmission electron The obtained CIS and CIS/ZnS core/shell NCs are quasimonodisperse with an average particle size of 2.4 and 4.6 nm, respectively. All of the as-synthesized NCs can be well dispersed in toluene or hexane to form stable and clear colloidal solutions, which show strong visible emission (blue for CIS/ZnS core/shell NCs) under UV excitation. The growth of a ZnS shell on CIS NCs, that is, the formation of CIS/ZnS core/shell NCs, resulted in an impact enhancement in the PL intensity compared to that of bare CIS NCs due to the eliminated surface defects and the reduced lattice mismatch between the core and shell materials. A dramatic increase of the PL intensity can be obtained from the ZnS-capped CIS with respect to that of the bare CIS NCs. (C) 2008 Elsevier B.V. All rights reserved.
Synthesis and characterization of highly luminescent CuInS2 and CuInS2/ZnS (core/shell) nanocrystals
(2008-12-01)
Kuo, Kuan-Ting
;
Chen, San-Yuan
;
Cheng, Bing-Ming
;
Lin, Chin-Ching
;
材料科學與工程學系
High-quality CuInS2/ZnS (core-shell) nanocrystals (NCs) were synthesized via a colloidal solvent process and characterized for their optical properties by UV-vis, room temperature solution photoluminescence (PL) spectroscopy, and further obtained powders were characterized by X-ray microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and dynamic light scattering (DLS). diffraction (XRD), transmission electron The obtained CIS and CIS/ZnS core/shell NCs are quasimonodisperse with an average particle size of 2.4 and 4.6 nm, respectively. All of the as-synthesized NCs can be well dispersed in toluene or hexane to form stable and clear colloidal solutions, which show strong visible emission (blue for CIS/ZnS core/shell NCs) under UV excitation. The growth of a ZnS shell on CIS NCs, that is, the formation of CIS/ZnS core/shell NCs, resulted in an impact enhancement in the PL intensity compared to that of bare CIS NCs due to the eliminated surface defects and the reduced lattice mismatch between the core and shell materials. A dramatic increase of the PL intensity can be obtained from the ZnS-capped CIS with respect to that of the bare CIS NCs. (C) 2008 Elsevier B.V. All rights reserved.
Urokinase-type Plasminogen Activator Resulting from Endometrial Carcinogenesis Enhances Tumor Invasion and Correlates with Poor Outcome of Endometrial Carcinoma Patients
(2015-06-02)
Huang, Chia-Yen
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Chang, Ming-Cheng
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Huang, Wei-Yun
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Huang, Ching-Ting
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Tang, Yu-Chien
The purpose of this study was to identify the dysregulated genes involved in the tumorigenesis and progression of endometrial endometrioid adenocarcinoma (EEC), and their possible mechanisms. Endometrial specimens including normal endometrial tissues, atypical endometrial hyperplasia, and EEC were analyzed. The expression profiles were compared using GeneChip Array. The gene expression levels were determined by real-time RT-PCR in the training and testing sets to correlate the clinico-pathological parameters of EEC. Immunoblotting, in vitro cell migration and invasion assays were performed in human endometrial cancer cell lines and their transfectants. In microarray analysis, seven dysregulated genes were identified. Only the levels of urokinase-type plasminogen activator (uPA) were higher in EEC with deep myometrial invasion, positive lympho-vascular space invasion, lymph node metastasis, and advanced stages. After multivariate analysis, uPA was the only independent poor prognostic factor for disease-free survival in the EEC patients (hazard ratio: 4.65, p - 0.03). uPA may enhance the migratory and invasive capabilities of endometrial tumor cells by the phosphorylation of ERK1/2, Akt and p38 molecules. uPA is a dysregulated gene involved in the tumorigenesis, bio-pathological features and outcomes of EEC. uPA may be a potential molecule and target for the detection and treatment of EEC.
Variational Recurrent Neural Networks for Speech Separation
(2017-01-01)
Chien, Jen-Tzung
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Kuo, Kuan-Ting
;
電機工程學系
;
Department of Electrical and Computer Engineering
We present a new stochastic learning machine for speech separation based on the variational recurrent neural network (VRNN). This VRNN is constructed from the perspectives of generative stochastic network and variational auto-encoder. The idea is to faithfully characterize the randomness of hidden state of a recurrent neural network through variational learning. The neural parameters under this latent variable model are estimated by maximizing the variational lower bound of log marginal likelihood. An inference network driven by the variational distribution is trained from a set of mixed signals and the associated source targets. A novel supervised VRNN is developed for speech separation. The proposed VRNN provides a stochastic point of view which accommodates the uncertainty in hidden states and facilitates the analysis of model construction. The masking function is further employed in network outputs for speech separation. The benefit of using VRNN is demonstrated by the experiments on monaural speech separation.