Browsing by Issue Date, starting with "2012-07-10"

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Absorption and fluorescence spectra of the neutral and anionic green fluorescent protein chromophore: Franck-Condon simulation
(2012-07-10)
Huang, Tsung-wei
;
Yang, Ling
;
Zhu, Chaoyuan
;
Lin, Sheng Hsien
;
應用化學系分子科學碩博班
Absorption and fluorescence spectra of the neutral and anionic green fluorescent protein (GFP) chromophore, namely p-hydroxybenzylideneimidazolidinone (p-HBDI), have been simulated using the Franck-Condon factors including inhomogeneous broadening of solvent effect. Ground and the first excited states were calculated by time dependent density functional theory with and without the polarizable continuum model environment. Simulated peak of the neutral/anionic p-HBDI at 380 nm (423 nm)/421 nm agrees with experiment value 370 nm (434 nm)/419 nm for absorption (fluorescence) spectrum. Simulated width of the neutral/anionic p-HBDI at 0.51 eV (0.54 eV)/0.57 eV agrees with experiment value 0.54 eV (0.66 eV)/0.56 eV for absorption (fluorescence) spectrum. (C) 2012 Elsevier B. V. All rights reserved.
Label-free sensor
(2012-07-10)
Meng Hsin-Fei
;
Hong Sheng-Fu
;
Chao Yu-Chiang
;
Liu Chien-Cheng
;
Liu Wen-Hsing
The invention provides a label-free sensor that includes a substrate, a first electrode formed on the substrate, a second electrode formed on the substrate and spaced away from the first electrode, and a semiconductor layer formed on the substrate and being in contact with the first electrode and the second electrode. The semiconductor layer has a plurality of probe groups bonded to the semiconductor layer by functionalization, for sensing a coupling-specific substance having bonding specificity with the probe groups. The semiconductor layer is bonded with the probe groups, and the detection of detected object is performed in an instant, quick, rapid, and sensitive manner by measuring variation in electric current, avoiding the use of fluorescent reading equipment for reading fluorescent signals.
Achieving High Field-Effect Mobility in Amorphous Indium-Gallium-Zinc Oxide by Capping a Strong Reduction Layer
(2012-07-10)
Zan, Hsiao-Wen
;
Yeh, Chun-Cheng
;
Meng, Hsin-Fei
;
Tsai, Chuang-Chuang
;
Chen, Liang-Hao
Method for OFDM and OFDMA channel estimation
(2012-07-10)
Hung Kun-Chien
;
Lin David W.
This invention discloses a method for OFDM and OFDMA channel estimation via phase-rotated polynomial interpolation and extrapolation (inter/extra-polation). For complexity reason, polynomial inter/extra-polation is an often considered method for channel estimation in orthogonal frequency-division multiplexing (OFDM) and orthogonal frequency-division multiple access (OFDMA) systems, in which the simplest choice is linear inter/extra-polation. But the performance of this method depends on the accuracy of symbol timing estimation as well as the channel delay spread. The invention mitigates the problem by adding a linear phase factor to polynomial inter/extra-polation, which corresponds to adding a delay (also called delay shift) in the time domain.
Tracking vehicle method by using image processing
(2012-07-10)
Wu Bing-Fei
;
Chen Chao-Jung
;
Kao Chih-Chung
;
Chung Meng-Liang
;
Chiu Chung-Cheng
The invention relates to a method for image processing. First, establish the initial image background information. And retrieve the instant image information. Then calculate the initial image background information and color intensity information of the instant image. Furthermore, adjust the instant image information. Then calculate the moving-object information. Finally, track the moving-object information. It can improve the accuracy rate of detection without the influence of erected height.
Symbol time synchronization method for OFDM systems
(2012-07-10)
Chin Wen-Long
;
Chen Sau-Gee
A symbol time synchronization method for OFDM systems is disclosed. The invention presents a joint maximum-likelihood (ML) synchronization method for symbol time offset (STO) in OFDM systems. The method is developed in frequency domain under time-variant multipath channels. By analyzing the received frequency-domain data, a mathematical model for the joint effects of symbol time offset (STO), carrier frequency offset (CFO) and sampling clock frequency offset (SCFO) is derived. The results are used to formulate a log-likelihood function of two consecutive symbols. The joint estimation's method is robust, because it exhibits high performances in high mobility and time-variant multipath fading channels.
重估一通道脈衝響應之方法、裝置及其電腦程式產品
(2012-07-11)
吳文榕
;
賴允仁
一種重估一通道脈衝響應之方法、裝置及電腦程式產品。該通道脈衝響應包含複數個通道切片，且對應至一通道頻率響應。該方法包含下列步驟：選取該等通道切片其中之一以作為一選定通道切片，其餘作為至少一待處理通道切片；扣除該至少一待處理通道切片對該通道頻率響應之影響，以得一第一通道頻率響應；以一最小平方法及該第一通道頻率響應，更新該選定通道切片；以及將該選定通道切片置換為更新後之該選定通道切片。藉此，可提高通道估測的準確度。
利用時域反射量測懸浮質濃度的方法及其裝置改良
(2012-07-11)
林志平
;
鐘志忠
本發明利用時域反射(Time domain reflectometry,TDR)之原理提出量測懸浮液中懸浮質濃度的裝置與方法改良，該裝置主要包含一可穩定量測電磁波走時的導波器及一溫度感測器，方法中主要係量測感測裝置在懸浮液中之電磁波來回走時及溫度，並利用一已建立之含溫度修正之電磁波走時-懸浮質濃度率定關係，來分析該懸浮液中懸浮質濃度。本發明提高TDR方法的懸浮質濃度量測準確度，且不受懸浮液導電度及懸浮質粒徑之影響，使之可適用於一般工程應用及環境監測之需求。
無石英震盪器之通訊收發裝置與可自我校正時脈輸出之方法
(2012-07-11)
李鎮宜
;
游瑞元
一種通訊裝置利用一時脈產生器以更新輸出一來自遠端通訊裝置之參考訊號之載波頻率。本發明特別是利用一封閉迴路用以自我校正本地端時脈使其頻率在一固定誤差範圍內之後，一訊號解碼解調變器將解碼參考訊號以輸出資料訊號。
Effect of electron-vibration interactions on the thermoelectric efficiency of molecular junctions
(2012-07-11)
Hsu, Bailey C.
;
Chiang, Chi-Wei
;
Chen, Yu-Chang
;
電子物理學系
;
Department of Electrophysics
From first-principles approaches, we investigate the thermoelectric efficiency of a molecular junction where a benzene molecule is connected directly to the platinum electrodes. We calculate the thermoelectric figure of merit ZT in the presence of electron-vibration interactions with and without local heating under two scenarios: linear response and finite bias regimes. In the linear response regime, ZT saturates around the electrode temperature T-e = 25 K in the elastic case, while in the inelastic case we observe a non-saturated and a much larger ZT beyond T-e = 25 K attributed to the tail of the Fermi-Dirac distribution. In the finite bias regime, the inelastic effects reveal the signatures of the molecular vibrations in the low-temperature regime. The normal modes exhibiting structures in the inelastic profile are characterized by large components of atomic vibrations along the current density direction on top of each individual atom. In all cases, the inclusion of local heating leads to a higher wire temperature T-w and thus magnifies further the influence of the electron-vibration interactions due to the increased number of local phonons.
Immersion Lithography Apparatus and Tank Thereof
(2012-07-12)
Hung Kuo-Yung
;
Tseng Fan-Gang
A tank for an immersion lithography apparatus provided. The tank has a container with a bottom plate and side plates connected to each, wherein the side plates surround and connect all edges of the bottom plate. The container is filled in at least a liquid having a refractive index thereof from about 1.4 to about 1.8. A platform is located in the container and immersed in the liquid. The platform has an axle fastened on a side thereof parallel to the bottom plate, wherein the axle passes through a bearing hole penetrated through one of the side plates. A roller disposed outside the container connects to the axle to rotate the axle, and furthermore, to incline the platform accordingly.
A nano switch mechanism for the redox-responsive sulfotransferase
(2012-07-15)
Lin, Chih-Heng
;
Lin, En-Shyh
;
Su, Tian-Mu
;
Hung, Kuo-Sheng
;
Yang, Yuh-Shyong
Cellular redox signaling is important in diverse physiological and pathological processes. The activity of rat phenol sulfotransferase (rSULT1A1), which is important for the metabolism of hormone and drug, is subjected to redox regulation. Two cysteines, Cys232 and Cys66, nanometer away from each other and from the enzyme active site were proposed to form disulfide bond to regulate the activity of rSULT1A1. A nano switch, composed of a flexible loop from amino acid residues 59-70, explained how this long distance interaction between two cysteines can be achieved. The enzyme properties were investigated through site-directed muatagnesis, circular dichroism, enzyme kinetics and homologous modeling of the rSULT1A1 structures. We proposed that the formation of disulfide bond between Cys232 and Cys66 induced conformational changes of sulfotransferase, then in turn affected its nucleotide binding and enzyme activity. This discovery was extended to understand the possible redox regulation of other sulfotransferases from different organisms. The redox switch can be created in other redox-insensitive sulfotransferases, such as human phenol sulfotransferase (hSULT1A1) and human alcohol sulfotransferase (hSULT2A1), to produce mutant enzymes with redox regulation capacity. This study strongly suggested that redox regulation of drug and hormone metabolism can be significantly varied even though the sequence and structure of SULT1A1 of human and rat have a high degree of homology. (C) 2012 Elsevier Inc. All rights reserved.
Room-Temperature Electro-Luminescence of Type-II GaSb/GaAs Quantum Rings
(2012-07-15)
Lin, Wei-Hsun
;
Lin, Meng-Yu
;
Wu, Shung-Yi
;
Lin, Shih-Yen
;
光電工程學系
The influence of Sb/background As flux ratios on GaSb nano-structures is investigated in this letter. With decreasing Sb/background As flux ratios under high Sb irradiation during the post soaking procedure, ring formation, photoluminescence (PL) intensity enhancement, and PL peak red shift are observed. With further reduced Sb flux and Sb/background As ratios, the observed more intense PL intensities of the quantum-ring (QR) samples compared with quantum dots suggest that more electron-hole wave function overlapping is obtained. The observation of room-temperature electro-luminescence of a QR PIN diode has revealed the potential of the nano-structure in light-emitting device application.
miR-103/107 Promote Metastasis of Colorectal Cancer by Targeting the Metastasis Suppressors DAPK and KLF4
(2012-07-15)
Chen, Hsin-Yi
;
Lin, Yu-Min
;
Chung, Hsiang-Ching
;
Lang, Yaw-Dong
;
Lin, Ching-Jung
Metastasis is the major cause of poor prognosis in colorectal cancer (CRC), and increasing evidence supports the contribution of miRNAs to cancer progression. Here, we found that high expression of miR-103 and miR-107 (miR-103/107) was associated with metastasis potential of CRC cell lines and poor prognosis in patients with CRC. We showed that miR-103/107 targeted the known metastasis suppressors death-associated protein kinase (DAPK) and Kruppel-like factor 4 (KLF4) in CRC cells, resulting in increased cell motility and cell-matrix adhesion and decreased cell-cell adhesion and epithelial marker expression. miR-103/107 expression was increased in the presence of hypoxia, thereby potentiating DAPK and KLF4 downregulation and hypoxia-induced motility and invasiveness. In mouse models of CRC, miR-103/107 overexpression potentiated local invasion and liver metastasis effects, which were suppressed by reexpression of DAPK or KLF4. miR-103/107-mediated downregulation of DAPK and KLF4 also enabled the colonization of CRC cells at a metastatic site. Clinically, the signature of a miR-103/107 high, DAPK low, and KLF4 low expression profile correlated with the extent of lymph node and distant metastasis in patients with CRC and served as a prognostic marker for metastasis recurrence and poor survival. Our findings therefore indicate that miR-103/107-mediated repression of DAPK and KLF4 promotes metastasis in CRC, and this regulatory circuit may contribute in part to hypoxia-stimulated tumormetastasis. Strategies that disrupt this regulation might be developed to block CRC metastasis. Cancer Res; 72(14); 3631-41. (c) 2012 AACR.
Light Extraction Enhancement of GaN-Based Light-Emitting Diodes Using Crown-Shaped Patterned Sapphire Substrates
(2012-07-15)
Chiu, Ching-Hsueh
;
Hsu, Lung-Hsing
;
Lee, Chia-Yu
;
Lin, Chien-Chung
;
Lin, Bo-Wen
In this letter, we report the high performance GaN-based light-emitting diodes (LEDs) with embedded air void array grown by metal-organic chemical vapor deposition. The donut-shaped air void was formed at the interface between crown-shaped patterned sapphire substrates (CPSS) and the GaN epilayer by conventional photolithography. The transmission electron microscopy images demonstrate that the threading dislocations were significantly suppressed by epitaxial lateral overgrowth (ELOG). The Monte Carlo ray-tracing simulation reveals that the light extraction of the air-voids embedded LED was dramatically increased due to a strong light reflection and redirection by the air voids.
A polarization-independent liquid crystal phase modulation using polymer-network liquid crystals in a 90 degrees twisted cell
(2012-07-15)
Lin, Yi-Hsin
;
Chen, Ming-Syuan
;
Lin, Wei-Chih
;
Tsou, Yu-Shih
;
光電工程學系
A polarization-independent liquid crystal phase modulation using polymer-network liquid crystals in a 90 degrees twisted cell (T-PNLC) is demonstrated. T-PNLC consists of three layers. Liquid crystal (LC) directors in the two layers near glass substrates are orthogonal to each other and those two layers modulate two eigen-polarizations of an incident light. As a result, two eigen-polarizations of an incident light experience the same phase shift. In the middle layer, LC directors are perpendicular to the glass substrate and contribute no phase shift. The phase shift of T-PNLC is electrically tunable and polarization-independent. T-PNLC does not require any bias voltage for operation. The phase shift is 0.28 pi rad for the voltage of 30 V-rms. By measuring and analyzing the optical phase shift of T-PNLC at the oblique incidence of transverse magnetic wave, the pretilt angle of LC directors and the effective thickness of three layers are obtained and discussed. The potential applications are spatial light modulators, laser beam steering, and micro-lens arrays. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4737260]
Design, Fabrication, and Characterization of Si-Based ARROW-B Photonic Crystal Sharp-Bend Waveguides and Power Splitters
(2012-07-15)
Chen, Jian-Hua
;
Huang, Yang-Tung
;
Yang, Yu-Lin
;
Lu, Ming-Feng
;
生物科技學系
Si-based type-B antiresonant reflecting optical waveguide (ARROW-B) photonic crystal waveguides (PCWs) with 60 degrees bend, 120 degrees bend, and Y-branch power splitter were first successfully fabricated and characterized. A simple capsule-shaped defect was designed to modulate the 60 degrees and 120 degrees photonic crystal (PC) bend corners and Y-branch PC power splitters. In the preliminary experiments, the average bend losses of 60 degrees and 120 degrees PC bend waveguides for both polarizations were lower than 1.5 and 4.2 dB/bend, respectively. For the Y-branch PC power splitters, power imbalances for both polarizations were all lower than 0.7 dB. It shows that the fabricated Si-based ARROW-B PCWs can provide good light sharp-bend ability and power-split ability.
The Influence of the Thermal Effect on CdSe/ZnS Quantum Dots in Light-Emitting Diodes
(2012-07-15)
Chen, Kuo-Ju
;
Chen, Hsin-Chu
;
Shih, Min-Hsiung
;
Wang, Chao-Hsun
;
Kuo, Ming-Yen
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.
Near-field scanning optical microscopy using a super-resolution cover glass slip
(2012-07-16)
Lin, Yu-Hsuan
;
Tsai, Din Ping
;
電子物理學系
;
Department of Electrophysics
This study presents a novel near-field optics technology. A near-field cover glass slip (NF-CGS) was developed to improve the resolution of optical microscopy beyond the diffraction limit. A multi-layered structure of cover glass/ZnS-SiO2 (130 nm)/AgOx (15 nm)/ ZnS-SiO2 (40 nm) was employed to generate the optical coupling effect for increasing the contrast and enhancing resolution of imaging. This novel innovation is expected to be employed in near-field imaging techniques for samples in different environments because of its simplicity, rapid laser scanning, and minimal costs. Experimental results of 500 nm, 200 nm, and 100 nm standard polystyrene nanospheres on NF-CGS and normal cover glass are demonstrated and imaged by using a laser scanning confocal microscope. (C) 2012 Optical Society of America
Control of growth and inflammatory response of macrophages and foam cells with nanotopography
(2012-07-16)
Mohiuddin, Mohammed
;
Pan, Hsu-An
;
Hung, Yao-Ching
;
Huang, Guewha Steven
;
材料科學與工程學系
Macrophages play an important role in modulating the immune function of the human body, while foam cells differentiated from macrophages with subsequent fatty streak formation play a key role in atherosclerosis. We hypothesized that nanotopography modulates the behavior and function of macrophages and foam cells without bioactive agent. In the present study, nanodot arrays ranging from 10aEuro to 200aEuronm were used to evaluate the growth and function of macrophages and foam cells. In the quantitative analysis, the cell adhesion area in macrophages increased with 10- to 50-nm nanodot arrays compared to the flat surface, while it decreased with 100- and 200-nm nanodot arrays. A similar trend of adhesion was observed in foam cells. Immunostaining, specific to vinculin and actin filaments, indicated that a 50-nm surface promoted cell adhesion and cytoskeleton organization. On the contrary, 200-nm surfaces hindered cell adhesion and cytoskeleton organization. Further, based on quantitative real-time polymerase chain reaction data, expression of inflammatory genes was upregulated for the 100- and 200-nm surfaces in macrophages and foam cells. This suggests that nanodots of 100aEuroaEuro parts per thousand and 200aEuronm triggered immune inflammatory stress response. In summary, nanotopography controls cell morphology, adhesions, and proliferation. By adjusting the nanodot diameter, we could modulate the growth and expression of function-related genes in the macrophages and foam cell system. The nanotopography-mediated control of cell growth and morphology provides potential insight for designing cardiovascular implants.