Browsing by Issue Date, starting with "2010-04-01"

Now showing 1 - 20 of 46597

The C-Terminus of a Subunit Determines The Catalytic Activity of AMP-activated Protein Kinase
(2010-04-01)
Cui, Xiaopei
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Gao, Haiqing
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Hwang, Jenn-Kang
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Shyy, John Y-J
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生物資訊及系統生物研究所
A Robust Channel Estimator for High-Mobility STBC-OFDM Systems
(2010-04-01)
Chen, Hsiao-Yun
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Ku, Meng-Lin
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Jou, Shyh-Jye
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Huang, Chia-Chi
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電機工程學系
In this paper, a robust channel estimator for high-mobility space-time block code-orthogonal frequency division multiplexing (STBC-OFDM) systems is proposed and applied in IEEE 802.16e systems. A high-performance two-stage channel estimation method is adopted. The proposed architecture reduces computational complexity effectively and improves 85.2% of the hardware implementation. The performances of the proposed design have been demonstrated through the simulation of an STBC-OFDM system with two transmit antennas and one receive antenna. At the vehicle speed of 120 and 240 km/hr for quadrature phase shift keying (QPSK) modulation, the proposed design can achieve the bit-error rate (BER) of about 10(-4) and 10(-3) without using channel coding. Moreover, it has significant performance improvement as compared with interpolation-based channel estimation methods. The proposed channel estimator implemented in 90 nm CMOS technology can support up to 29.03 Mbps (uncoded) downlink data transmission. The design only requires 859.6 K gates and dissipates 43.71 mW at 83.3 MHz operating frequency with 1 V power supply.
Impacts of Coulomb Interactions on the Magnetic Responses of Excitonic Complexes in Single Semiconductor Nanostructures
(2010-04-01)
Chang, Wen-Hao
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Lin, Chia-Hsien
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Fu, Ying-Jhe
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Lin, Ta-Chun
;
Lin, Hsuan
We report on the diamagnetic responses of different exciton complexes in single InAs/GaAs self-assembled quantum dots (QDs) and quantum rings (QRs). For QDs, the imbalanced magnetic responses of inter-particle Coulomb interactions play a crucial role in the diamagnetic shifts of excitons (X), biexcitons (XX), and positive trions (X (-) ). For negative trions (X (-) ) in QDs, anomalous magnetic responses are observed, which cannot be described by the conventional quadratic energy shift with the magnetic field. The anomalous behavior is attributed to the apparent change in the electron wave function extent after photon emission due to the strong Coulomb attraction by the hole in its initial state. In QRs, the diamagnetic responses of X and XX also show different behaviors. Unlike QDs, the diamagnetic shift of XX in QRs is considerably larger than that of X. The inherent structural asymmetry combined with the inter-particle Coulomb interactions makes the wave function distribution of XX very different from that of X in QRs. Our results suggest that the phase coherence of XX in QRs may survive from the wave function localization due to the structural asymmetry or imperfections.
Pulsed Electromagnetic Fields Accelerate Proliferation and Osteogenic Gene Expression in Human Bone Marrow Mesenchymal Stem Cells During Osteogenic Differentiation
(2010-04-01)
Sun, Li-Yi
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Hsieh, Dean-Kuo
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Lin, Po-Cheng
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Chiu, Hsien-Tai
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Chiou, Tzyy-Wen
Osteogenesis is a complex series of events involving the differentiation of mesenchymal stem cells to generate new bone. In this study, we examined the effect of pulsed electromagnetic fields (PEMFs) on cell proliferation, alkaline phosphatase (ALP) activity, mineralization of the extracellular matrix, and gene expression in bone marrow mesenchymal stem cells (BMMSCs) during osteogenic differentiation. Exposure of BMMISCs to PEMFs increased cell proliferation by 29.6% compared to untreated cells at day 1 of differentiation. Semi-quantitative RT-PCR indicated that PEMFs significantly altered temporal expression of osteogenesis-related genes, including a 2.7-fold increase in expression of the key osteogenesis regulatory gene cbfa1, compared to untreated controls. In addition, exposure to PEMFs significantly increased ALP expression during the early stages of osteogenesis and substantially enhanced mineralization near the midpoint of osteogenesis. These results suggest that PEMFs enhance early cell proliferation in B M MSC-mediated osteogenesis, and accelerate the osteogenesis. Bioelectromatmetics 31:209-219, 2010. (C) 2009 Wiley-Liss, Inc.
Crystal quality improvement of a-plane GaN using epitaxial lateral overgrowth on nanorods
(2010-04-01)
Ling, Shih-Chun
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Chao, Chu-Li
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Chen, Jun-Rong
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Liu, Po-Chun
;
Ko, Tsung-Shine
The crystal quality of a-plane GaN films was improved by using epitaxial lateral overgrowth on nanorod GaN template. The scanning electron microscope images showed the fully coalesced regrowth process completed within only 2 mu m thickness. The a-plane GaN films grown on nano-rod template showed superior surface quality and less surface pits. The on-axis and off-axis FWHMs of X-ray rocking curves decreased with the increase in the etching depth of the nano-rod template. TEM analysis revealed that the dislocation density was reduced to around 1.2 x 10(9) cm(-2) by the nano-rod epitaxial lateral overgrowth. In addition, the photoluminescence intensity of the a-plane GaN was enhanced significantly. These results demonstrated the opportunity of achieving a-plane GaN films with high crystal quality via nano-rod epitaxial lateral overgrowth. (C) 2009 Elsevier B.V. All rights reserved.
Hemoglobin induced oxidative stress is associated with both endogenous peroxidase activity and H2O2 generation from polyunsaturated fatty acids
(2010-04-01)
Cheng, Tsai-Mu
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Pan, Ju-Pin
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Chen, Hong-Wei
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Chang, Yi-Chun
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Chang, Chia-Ching
AN OPTIMAL MARKET ENTRY/EXIT EVALUATION MODEL WITH PARTIAL FINANCING FUNDS
(2010-04-01)
Lin, Tyrone T.
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Ko, Chuan-Chuan
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Liu, Chien-Yu
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經營管理研究所
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Institute of Business and Management
The paper mainly aims to introduce the real options approach to construct an evaluation model for the firm value under partial financing funds. The paper examines that production volume follows the geometric Brownian motion and considers that both the market entry of investment cost and the market exit of withdrawal cost match the linear function with production volume. Then the paper evaluates the potential firm value before market entry, the operational value with the firm's operating, and the market exit value with the firm's stopping to operate so as to assess the whole firm value, shareholder value, and bondholder value hereafter. The results show that different debt ratios will affect the firm's investment decision. The paper figures out the optimal decision-making based on the maximum profit of shareholders or the maximum profit of shareholders-and-bondholders. The factor is finance leverage; although interest expenses are tax deductible, an overly high leverage may trigger agency costs for a firm, which will offset the tax shields associated with leverage. Therefore, a firm should not leverage too much. Furthermore, the paper constructs an innovative evaluation model in a dynamic financing environment in order to provide the management team with a decision-making mechanism for their decisions in market entry or market exit in a timely manner in the face of uncontrollable exogenous variables.
Experimental and theoretical studies of Sn(3-delta)Pb(delta)Bi(2)Se(6) (delta=0.0-0.7)
(2010-04-01)
Chen, Kuei-Bo
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Lee, Chi-Shen
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應用化學系
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Department of Applied Chemistry
New ternary and quaternary chalcogenides, Sn(3-delta)Pb(delta)Bi(2)Se(5) (delta=0.0-0.7), were synthesized from pure elements using the solid-state method. Their crystal structures, determined using single crystal X-ray diffraction, belong to the orthorhombic space group Pnma (No. 62). The structure is related to Pb(3)Bi(2)S(6), which contains NaCl [311] layer units and zigzag arrays of metal atoms along the c-axis. A correlation between the Pb composition and the shifted position of a metal site was observed. Band structure calculations confirmed that the structure is stabilized when the position of the M5 site is farther from the mirror plane. Thermopower and conductivity measurements indicated that all of the compounds are n-type semiconductors with small band gaps. (C) 2010 Elsevier Inc. All rights reserved.
Magnetic fluctuations in FeSe1-delta and Cu-doped FeSe1-delta: Se-77 NMR experiments
(2010-04-01)
Young, Ben-Li
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Wu, Jack
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Huang, Tzu-Wen
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Yeh, Kuo-Wei
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Wu, Maw-Kuen
The roles of Se deficiency and Fe atoms, for the superconductivity of FeSe, have been, respectively, investigated in FeSe1-delta and (Fe1-xCux)Se1-delta, by our NMR experiments. The data, for nuclear spin-lattice relaxation rate (1/T-1), show that the spin fluctuations are weakened at a larger delta, and are correlated with the superconductivity in FeSe. The superconducting volume fraction, estimated by our ac susceptibility experiments, is found to vary inversely with delta. Our findings suggest that the Se-deficient FeSe has an inhomogeneous phase, where the superconductivity is associated with the regions having few or no Se vacancies. As for (Fe1-xCux)Se1-delta, T-c is rapidly suppressed by Cu doping and vanishes around x=0.03. The Se-77 and the Cu-63 NMR linewidths suggest that a local moment is induced at the Fe sites and not at the Cu sites. However, 1/T-1 shows no obvious change with the Cu doping. We suspect that other effects, such as disorder or change in the density of states, have more influence on T-c suppression since a metal-insulator transition, induced by Cu substitution, occurs in the resistivity measurements.
A multi-subwaveform parametric retracker of the radar satellite altimetric waveform and recovery of gravity anomalies over coastal oceans
(2010-04-01)
Guo JinYun
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Gao YongGang
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Hwang, CheinWay
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Sun JiaLong
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土木工程學系
The quality of satellite radar altimetric data is very important in studies of geodesy, geophysics, and oceanography. Over coastal oceans, altimeter waveforms are contaminated by the terrain and physical environments so that the accuracy of altimeter data is lower than that over open oceans. Here we develop a new multi-subwaveform parametric retracker (MSPR) to improve the quality of altimeter data for the recovery of gravity anomaly in coastal oceans. The least squares collocation method is used to recover the residual gravity anomaly over the coastal water from altimetric data. The waveform data records from Geosat/GM around Taiwan Island are practically retracked with MSPR. When compared with the Taiwan geoid height, the results retracked by MSPR are more accurate than those retracked by the well-known beta-5-parmeter method and from the geophysical data records (GDRs). The gravity anomalies over Taiwan coastal waters are calculated from the retracked altimeter data with the least squares collocation. When we compared gravity anomalies computed using altimeter GDRs with the ship-borne gravity data over Taiwan coastal ocean, we found that the results from retracked data are more accurate than those from GDRs.
Asymmetric gate capacitance and dynamic characteristic fluctuations in 16 nm bulk MOSFETs due to random distribution of discrete dopants
(2010-04-01)
Lee, Kuo-Fu
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Li, Yiming
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Hwang, Chih-Hong
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傳播研究所
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電機工程學系
Characteristic variability of a transistor is a crucial issue for nanoscale metal-oxide-semiconductor field-effect transistors (MOSFETs). In this study, we explore the asymmetric sketch of the random dopant distribution near the source end and the drain end in 16 nm MOSFETs. Discrete dopants near the source and drain ends of the channel region induce rather different fluctuations in gate capacitance and dynamic characteristics. Based upon the observed asymmetry properties, a lateral asymmetry channel doping profile engineering is then proposed to suppress the random-dopant-induced characteristic fluctuations in the examined devices and circuits. The results of this study indicate that the fluctuations in average gate capacitance, circuit gain, 3 db bandwidth and unity-gain bandwidth for the cases with dopants near the drain side could be simultaneously reduced by 62.6%, 22.2%, 63.1% and 41.4%, respectively. Consequently, such a lateral asymmetry channel doping profile could be considered to design intrinsic parameter fluctuation resistant transistors.
Minimizing the total weighted completion time in the relocation problem
(2010-04-01)
Kononov, Alexander V.
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Lin, Bertrand M. T.
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
This paper studies the minimization of total weighted completion time in the relocation problem on a single machine. The relocation problem, formulated from an area redevelopment project, can be treated as a resource-constrained scheduling problem. In this paper, we show four special cases to be NP-hard in the strong sense. Problem equivalence between the unit-weighted case and the UET (unit-execution-time) case is established. For two further restricted special cases, we present a polynomial time approximation algorithm and show its performance ratio to be 2.
The positive morpheme in Chinese and the adjectival structure
(2010-04-01)
Liu, Chen-Sheng Luther
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外國語文學系
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Department of Foreign Languages and Literatures
Chinese has a positive morpheme that has two allomorphs: a covert one and an overt one (i.e., the degree word hen). The former, behaving like a polarity item, only occurs in a predicate-accessible operator([-wh]) domain with a structure like [Op([-wh]) ... X([-wh-operator])(0) [(Deg P) ... Deg(0)[(AP) ... ]]], where the head X(0), carrying the predicate-accessible operator([-wh]) feature, not only introduces a predicate-accessible operator([-wh]) but also licenses the occurrence of a degree phrase headed by the covert positive morpheme (i.e., Deg(0)), while the latter in other contexts. Having this as basis, I propose a condition on saturating Chinese gradable adjectives through which the bifurcated use of the 'unmarked' form of Chinese gradable adjectives can be well captured. Besides, the obligatory overt realization of a covert positive morpheme occurring in a predicate-accessible operator([-wh]) domain, when the predicative adjective is substituted for by a pro-form, further implies that Chinese has an adjectival structure simpler than English. (C) 2009 Elsevier B.V. All rights reserved.
Role of Mst3 in oxidative phosphorylation
(2010-04-01)
Lin, Chia-Ying
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Wu, Hung-Yi
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Yuan, Chiun-Jye
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交大名義發表
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National Chiao Tung University
Predicting the Determinants of Users' Intentions for Using YouTube to Share Video: Moderating Gender Effects
(2010-04-01)
Yang, Chyan
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Hsu, Yi-Chun
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Tan, Suyanti
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
This research aims to improve understanding of what motivates individual online users to share their videos on YouTube and whether gender affects those motivations. The work proposes a model based on the technology acceptance model (TAM) and social influences theory by conducting a survey of 206 male and 135 female video sharers of YouTube to test this model. The results indicate that perceived ease of use is an important determinant of the intention to use YouTube to share video. All factors from the social influence perspective significantly affect the intention to use YouTube to share video. The results show that differences exist in sharing behavior between female and male users. Female users' intention is strongly influenced by usefulness and social norms, while male users' intention is strongly influenced by interpersonal norms. Based on those findings, implications for theory and practice are discussed.
Developing an advanced Multi-Temperature Joint Distribution System for the food cold chain
(2010-04-01)
Kuo, Ju-Chia
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Chen, Mu-Chen
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運輸與物流管理系註：原交通所+運管所
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Department of Transportation and Logistics Management
For temperature sensitive and perishable products (TSPPs) logistics, a special type of supply chain management called Cold Chain Management (CCM), has been established. Temperature monitoring and control are essential mechanisms in CCM, because they are necessary for maintaining food safety and quality. However, they are costly to logistics service providers (LSPs). In this paper, a logistics service model based on the advancement of the Multi-Temperature joint Distribution System, namely MTJD, is being proposed for the food cold chain. The proposed service model facilitates innovation in logistics services and gives the logistics sector a competitive advantage in the area of thermal protection for perishable shipments and temperature sensitive products. Smaller shipments and timely deliveries offer unique challenges when operating a cold chain. The MTJD-based model is designed with these challenges in mind. A case study is performed by using the regulative cycle. In this paper, an MTJD-based model is presented according to the requirements of the food chain and the operations of a 3PL in Taiwan. MTJD provides a new scheme for continuously temperature-controlled logistics, which can jointly deliver and store multi-temperature goods. (C) 2009 Elsevier Ltd. All rights reserved.
Timing Jitter and Modulation Profile Extraction for Spread-Spectrum Clocks
(2010-04-01)
Hsu, Jenchien
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Su, Chauchin
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper presents a built-in jitter measurement approach for measuring the timing jitter of spread-spectrum clocks (SSCs) and a jitter estimation method for validating the approach. Because of the lack of dedicated measurement instruments for SSC timing jitter measurement, the jitter estimation method is proposed to correlate SSC and non-SSC jitter. A 1.2-GHz eight-phase SSC generator with the jitter measurement circuit is designed and fabricated using the 0.18-mu m complementary metal-oxide semiconductor technology. The measured results are validated by the proposed estimation method, which is the key contribution of this paper. The experimental results show that the proposed built-in measurement approach has an error of less than 0.0026 UI.
Metadata-based image watermarking for copyright protection
(2010-04-01)
Huang, Hsiang-Cheh
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Fang, Wai-Chi
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交大名義發表
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National Chiao Tung University
In this paper, we propose a practical application for copyright protection of images with watermarking. The EXIF metadata of images and error-control codes are integrated into our algorithm and corresponding applications. Application for robust watermarking is one of the major branches in digital rights management (DRM) systems and digital forensics. Here, we focus on the copyright protection for images taken by ordinary cameras. By use of robust watermarking, it generally alters selected coefficients of the contents to accomplish the embedding process. Should the received image be in question, the watermark embedded beforehand can be extracted to indicate the copyright owner of such an image. We consider not only the image contents itself, but we also employ the EXIF metadata, which serves as the role of watermark, to be integrated into our scheme to make copyright protection possible. Moreover, for enhancing the performance for copyright protection, channel coding is employed and better protection capability can be expected. Taking the manufacturer, camera model, date and time stamp, and other important information in the EXIF metadata into account, conventional watermarking techniques can be applied to ordinary pictures taken by ourselves, and watermarked images with good quality can be produced. Even when the marked image has been intentionally modified, the original EXIF with selected information can mostly be recovered from the channel decoding process. Simulation results present the effectiveness of such an implementation. (C) 2009 Elsevier B.V. All rights reserved.
Multiple serological biomarkers for colorectal cancer detection
(2010-04-01)
Chan, Chung-Chuan
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Fan, Chung-Wei
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Kuo, Yung-Bin
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Chen, Yu-Han
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Chang, Pi-Yueh
The aim of this study was to initiate a survey of human autoantibody responses to a panel of select colorectal tumor-associated antigens identified by previous serological analysis of a cDNA expression library and to subsequently identify multiple serological biomarkers for the detection of colorectal cancer. For screening of autoantibodies against colorectal tumor-associated antigens, sera from 94 colorectal cancer patients and 54 normal controls were analyzed by enzyme-linked immunosorbent assay using recombinant rCCCAP, rHDAC5, rP53, rNMDAR and rNY-CO-16 proteins as coating antigens. Seropositivity among colorectal cancer patients to the 5 individual coating antigens varied from 18.1% to 35.1%. Seropositivity to any of the 5 coating antigens was 58.5% and combining this analysis with evaluation of serum carcinoembryonic antigen (>= 5 ng/ml) significantly increased the seropositivity to 77.6%. Seropositivity of early-stage (Dukes' Stages A and B) colorectal cancer patients to CEA was 21.9%, and seropositivity to any of the 5 colorectal cancer-associated antigens was 53.7%, and the combination of these 2 measurements resulted in a higher diagnostic capacity (65.9%) than either marker alone. In conclusion, these results collectively indicated that combined detection of serum autoantibody profiles against our panel of colorectal tumor-associated antigens and the analysis of carcinoembryonic antigen provides a promising diagnostic biomarker for colorectal cancer, particularly among early-stage patients.
感測元件、製造方法及其生物檢測系統
(2010-04-01)
許鉦宗
;
陳振嘉
;
李耀坤
;
張可欣
本發明係揭露一種感測元件、製造方法及其生物檢測系統。此感測元件包含一具有超薄通道之場效應電晶體、一參考電極、一第一頓化層、一第二頓化層以及一微流道。第一頓化層用以包覆場效應電晶體之第一部份，第二頓化層用以包覆場效應電晶體之第二部份，微流道與第一頓化層及第二頓化層接合，使其微流道橫跨於超薄通道場效應電晶體通道上。場效應電晶體一超薄通道表面以化學或物理方法修飾之，當一待測樣品透過微流道接觸超薄通道之表面時，超薄通道場效應電晶體之電導即可隨之改變達成微量偵測。