Browsing by Issue Date, starting with "2010-11-30"

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N-Ace: Using Solvent Accessibility and Physicochemical Properties to Identify Protein N-Acetylation Sites
(2010-11-30)
Lee, Tzong-Yi
;
Hsu, Justin Bo-Kai
;
Lin, Feng-Mao
;
Chang, Wen-Chi
;
Hsu, Po-Chiang
Protein acetylation, which is catalyzed by acetyltransferases, is a type of post-translational modification and crucial to numerous essential biological processes, including transcriptional regulation, apoptosis, and cytokine signaling. As the experimental identification of protein acetylation sites is time consuming and laboratory intensive, several computational approaches have been developed for identifying the candidates of experimental validation. In this work, solvent accessibility and the physicochemical properties of proteins are utilized to identify acetylated alanine, glycine, lysine, methionine, serine, and threonine. A two-stage support vector machine was applied to learn the computational models with combinations of amino acid sequences, and the accessible surface area and physicochemical properties of proteins. The predictive accuracy thus achieved is 5% to 14% higher than that of models trained using only amino acid sequences. Additionally, the substrate specificity of the acetylated site was investigated in detail with reference to the subcellular colocalization of acetyltransferases and acetylated proteins. The proposed method, N-Ace, is evaluated using independent test sets in various acetylated residues and predictive accuracies of 90% were achieved, indicating that the performance of N-Ace is comparable with that of other acetylation prediction methods. N-Ace not only provides a user-friendly input/output interface but also is a creative method for predicting protein acetylation sites. This novel analytical resource is now freely available at http://N-Ace.mbc.NCTU.edu.tw/. (C) 2010 Wiley Periodicals, Inc. J Comput Chem 31: 2759-2771, 2010
N-Ace: Using Solvent Accessibility and Physicochemical Properties to Identify Protein N-Acetylation Sites
(2010-11-30)
Lee, Tzong-Yi
;
Hsu, Justin Bo-Kai
;
Lin, Feng-Mao
;
Chang, Wen-Chi
;
Hsu, Po-Chiang
Protein acetylation, which is catalyzed by acetyltransferases, is a type of post-translational modification and crucial to numerous essential biological processes, including transcriptional regulation, apoptosis, and cytokine signaling. As the experimental identification of protein acetylation sites is time consuming and laboratory intensive, several computational approaches have been developed for identifying the candidates of experimental validation. In this work, solvent accessibility and the physicochemical properties of proteins are utilized to identify acetylated alanine, glycine, lysine, methionine, serine, and threonine. A two-stage support vector machine was applied to learn the computational models with combinations of amino acid sequences, and the accessible surface area and physicochemical properties of proteins. The predictive accuracy thus achieved is 5% to 14% higher than that of models trained using only amino acid sequences. Additionally, the substrate specificity of the acetylated site was investigated in detail with reference to the subcellular colocalization of acetyltransferases and acetylated proteins. The proposed method, N-Ace, is evaluated using independent test sets in various acetylated residues and predictive accuracies of 90% were achieved, indicating that the performance of N-Ace is comparable with that of other acetylation prediction methods. N-Ace not only provides a user-friendly input/output interface but also is a creative method for predicting protein acetylation sites. This novel analytical resource is now freely available at http://N-Ace.mbc.NCTU.edu.tw/. (C) 2010 Wiley Periodicals, Inc. J Comput Chem 31: 2759-2771, 2010
Fabrication of bismuth oxide-tin oxide nanowires by direct thermal oxidation of Bi-Sn eutectic nanowires
(2010-11-30)
Chen, Shih-Hsun
;
Wang, Chiu-Yen
;
Liu, Tzeng-Feng
;
Chao, Chuen-Guang
;
材料科學與工程學系
Bismuth oxide-tin oxide (BiO(x)-SnO(x)) heterostructure nanowires with a diameter of 70 nm were fabricated by directly annealing Bi-Sn eutectic nanowires synthesized by the vacuum hydraulic pressure injection process. After removal of AAO (Anodic Aluminum Oxide) template with an etching solution, a spontaneous oxide was formed on nanowires to enclose the Bi-Sn eutectic alloys While these nanowires went through the annealing process with the proper heating rate of 50 degrees C/min, the well-annealed oxide nanowires remain solid, straight and segmental The results of cathodoluminescence (CL) spectrum and photoresponse proved that the products consisted of bismuth oxide and tin oxide This fabrication methodology provides a simple way to produce one-dimensional oxide nanomatenals. (C) 2010 Elsevier B.V. All rights reserved
【學術專欄】以人工植牙與再生療法─治療嚴重牙周缺損病例的挑戰
(國立陽明大學牙醫校友會, 2010-12)
李明科
On Campus Beta Site: Architecture Designs, Operational Experience, and Top Product Defects
(2010-12-01)
Lin, Ying-Dar
;
Chen, I-Wei
;
Lin, Po-Ching
;
Chen, Chang-Sheng
;
Hsu, Chun-Hung
Testing network products in a beta site to reduce the possibility of customer found defects is a critical phase before marketing. We design and deploy an innovative beta site on the campus of National Chiao Tung University, Hsinchu, Taiwan. It can be used for developers to test and debug products, while maintaining network quality for network users. To satisfy the needs of developers, we set up environments and mechanisms, such as a variety of test zones for multiple types of products or systems under test (SUTs), remote control, degrees of traffic volume, and traffic profiling. For network users, we set up mechanisms of failure detection, notification, and recovery. The beta site network users are all volunteers. Test results show that beta site testing is good for finding stability and compatibility defects. The period starting from the beginning of a test until the next defect is found is called the time to fail (TTF). We call it converged if the TTF exceeds four weeks, and the convergence ratio is the percentage of SUTs that reach convergence. We find that the TTF increases with longer test duration, meaning that product quality improves through beta site testing. However, the convergence ratios are only 7 and 20 percent for test durations of one month and one year, respectively, meaning that few products operate faultlessly for a long duration. The convergence ratios also indicate that it takes much more time to enhance product quality to be converged. Therefore, if considering both marketing timing and product quality, one month is our suggested minimum TD for low-end and short-life-cycle products. However, we recommend one year as the minimum TD for high-end and long-life-cycle products.
人臉辨識與合成方法
(2010-12-01)
李秉翰
;
洪一平
本發明係提供一種辨識與合成人臉影像的方法，其步驟包括：找出人臉上的重要局部特徵與其基本類型;建立一資料庫；提供一人臉，並對該人臉的局部特徵進行編碼，以產生一第一人臉特徵碼；將該第一人臉特徵碼與該資料庫所儲存的資料逐一進行比對，並得出複數個差值；以及找出該複數個差值的最小值。在合成方面，針對一個給定的人臉特徵碼，將每個號碼所指定的基本類型拼湊成一張人臉。
Crystal Structure and Mutational Analysis of Aminoacylhistidine Dipeptidase from Vibrio alginolyticus Reveal a New Architecture of M20 Metallopeptidases
(2010-12-01)
Chang, Chin-Yuan
;
Hsieh, Yin-Cheng
;
Wang, Ting-Yi
;
Chen, Yi-Chin
;
Wang, Yu-Kuo
Aminoacylhistidine dipeptidases (PepD, EC 3.4.13.3) belong to the family of M20 metallopeptidases from the metallopeptidase H clan that catalyze a broad range of dipeptide and tripeptide substrates, including L-carnosine and L-homocarnosine. Homocarnosine has been suggested as a precursor for the neurotransmitter gamma-aminobutyric acid (GABA) and may mediate the antiseizure effects of GABAergic therapies. Here, we report the crystal structure of PepD from Vibrio alginolyticus and the results of mutational analysis of substrate-binding residues in the C-terminal as well as substrate specificity of the PepD catalytic domain-alone truncated protein PepD(CAT). The structure of PepD was found to exist as a homodimer, in which each monomer comprises a catalytic domain containing two zinc ions at the active site center for its hydrolytic function and a lid domain utilizing hydrogen bonds between helices to form the dimer interface. Although the PepD is structurally similar to PepV, which exists as a monomer, putative substrate-binding residues reside in different topological regions of the polypeptide chain. In addition, the lid domain of the PepD contains an "extra" domain not observed in related M20 family metallopeptidases with a dimeric structure. Mutational assays confirmed both the putative di-zinc allocations and the architecture of substrate recognition. In addition, the catalytic domain-alone truncated PepD(CAT) exhibited substrate specificity to L-homocarnosine compared with that of the wild-type PepD, indicating a potential value in applications of PepD(CAT) for GABAergic therapies or neuroprotection.
Computational algorithm and parameter optimization for a multi-server system with unreliable servers and impatient customers
(2010-12-01)
Wu, Chia-Huang
;
Ke, Jau-Chuan
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
We consider an infinite capacity M/M/c queueing system with c unreliable servers, in which the customers may balk (do not enter) and renege (leave the queue after entering). The system is analyzed as a quasi-birth-and-death (QBD) process and the necessary and sufficient condition of system equilibrium is obtained. System performance measures are explicitly derived in terms of computable forms. The useful formulae for computing the rate matrix and stationary probabilities are derived by means of a matrix analytical approach. A cost model is derived to determine the optimal values of the number of servers, service rate and repair rate simultaneously at the minimal total expected cost per unit time. The parameter optimization is illustrated numerically by the Quasi-Newton method. (C) 2010 Elsevier B.V. All rights reserved.
【第十二屆校友會會務】陽明牙醫診所暨陽明大學牙醫臨床教育中心營運報告
(國立陽明大學牙醫校友會, 2010-12)
白勝方
Analysis of pumping test data for determining unconfined-aquifer parameters: Composite analysis or not? (vol 17, pg 1133, 2009)
(2010-12-01)
Yeh, Hund-Der
;
Huang, Yen-Chen
;
環境工程研究所
;
Institute of Environmental Engineering
Intense blue-emitting Ca(2)PO(4)Cl:Eu(2+) phosphor for near-ultraviolet converting white light-emitting diodes
(2010-12-01)
Chiu, Yi-Chen
;
Liu, Wei-Ren
;
Chang, Chun-Kuei
;
Liao, Cheng-Chun
;
Yeh, Yao-Tsung
A blue phosphor Ca(2)PO(4)Cl:Eu(2+) (CAP:Eu(2+)) was synthesized by solid state reaction. The Ca(2)PO(4)Cl:Eu(2+) exhibited high quantum efficiency and excellent thermal stability. The luminescent intensity of Ca(2)PO(4)Cl:Eu(2+) was found to be 128% under excitation at 380 nm, 149% under 400 nm, and 247% under 420 nm as high as that of BaMgAl(10)O(17):Eu(2+). The optimal doping concentration was observed to 11 mol.% of CAP:Eu(2+). The energy transfer between Eu(2+) ions in CAP were occurred via electric multipolar interaction, and the critical transfer distance was estimated to be 1.26 nm. A mixture of blue-emitting Ca(2)PO(4)Cl:Eu(2+), green-emitting (Ba,Sr)(2)SiO(4):Eu(2+) and red-emitting CaAlSiN(3):Eu(2+) phosphors were selected in conjunction with 400 nm chip to fabricate white LED devices. The average color-rendering index R(a) and correlated color temperature (T(c)) of the white LEDs were found to be 93.4 and 4590 K, respectively. The results indicated that it was a promising candidate as a blue-emitting phosphor for the near-UV white light-emitting diodes.
Poly-Si Nanowire Nonvolatile Memory With Nanocrystal Indium-Gallium-Zinc-Oxide Charge-Trapping Layer
(2010-12-01)
Chen, Lun-Chun
;
Wu, Yung-Chun
;
Lin, Tien-Chun
;
Huang, Jyun-Yang
;
Hung, Min-Feng
This letter introduces a polycrystalline silicon (poly-Si) thin-film nonvolatile memory (NVM) with a nanocrystal (NC) indium-gallium-zinc-oxide (IGZO) charge-trapping layer. Experimental results indicate that this NVM exhibits high and symmetric program/erase speeds through the Fowler-Nordheim tunneling mechanism. The memory window loss of the NVM with NC IGZO charge-trapping layer is 25% after 10(4) s at 85 degrees C due to deep quantum well, as well as high-density and deep trap sites in NC IGZO charge-trapping layer. Accordingly, a poly-Si thin-film transistor with NC IGZO charge-trapping layer is promising for NVM applications.
Design and fabrication of a microplatform for the proximity effect study of localized ELF-EMF on the growth of in vitro HeLa and PC-12 cells
(2010-12-01)
Chen, Y. C.
;
Chen, C. C.
;
Tu, W.
;
Cheng, Y. T.
;
Tseng, F. G.
This paper presents a platform technology with experimental results that show the scientists and biologists a way to rapidly investigate and analyze the biological effects of localized extremely low frequency (ELF) electromagnetic field (EMF) on living cells. The proximity effect of the localized ELF-EMF on living cells is revealed using the bio-compatible microplatform on which an on-glass inductive coil array, the source of the localized ELF-EMF in micro scale, is designed, fabricated and operated with a field strength of 1.2 +/- 0.1 mT at 60 Hz for cell culturing study. After a 72 h ELF-EMF exposure, HeLa (human cervical cancer) and PC-12 (rat pheochromocytoma) cells exhibit about 18.4% and 12.9% cell proliferation rate reduction, respectively. Furthermore, according to the presented dynamic model, the reduction of the proliferation can be attributed to the interference of signal transduction processes due to the tangential currents induced around the cells.
【第十二屆校友會會務】台南區分會
(國立陽明大學牙醫校友會, 2010-12)
陳建璋
;
黃佳祥
Single-Ended Subthreshold SRAM With Asymmetrical Write/Read-Assist
(2010-12-01)
Tu, Ming-Hsien
;
Lin, Jihi-Yu
;
Tsai, Ming-Chien
;
Jou, Shyh-Jye
;
Chuang, Ching-Te
In this paper, asymmetrical Write-assist cell virtual ground biasing scheme and positive feedback sensing keeper schemes are proposed to improve the read static noise margin (RSNM), write margin (WM), and operation speed of a single-ended read/write 8 T SRAM cell. A 4 Kbit SRAM test chip is implemented in 90 nm CMOS technology. The test chip measurement results show that at 0.2 V V(DD), an operation frequency of 6.0 MHz can be achieved with power consumption of 10.4 mu W.
3-Formylpyrroles from 3-Furfurylamines by Bromine Oxidation Reaction
(2010-12-01)
Harn, Piin-Jye
;
Lin, Chu-Chung
;
Wu, Hsien-Jen
;
應用化學系
;
Department of Applied Chemistry
Oxidation of 3-furfurylamines 3a-e with bromine in acetone-water solution gave N-substituted 3-formylpyrroles 4a-e in good yields. A reaction mechanism via the Clauson-Kaas reaction followed by the cis-trans isomerization of the 2-ene-1,4-diones 13 and 14 was proposed to account for the formation of the pyrroles 4a-e.
【第十二屆校友會會務】北縣分會
(國立陽明大學牙醫校友會, 2010-12)
吕名峯
【第十二屆校友會會務】桃竹苗分會
(國立陽明大學牙醫校友會, 2010-12)
黃籌永
Applying loss aversion to assess the effect of customers' asymmetric responses to service quality on post-dining behavioral intentions: An empirical survey in the restaurant sector
(2010-12-01)
Chang, Kuo-Chien
;
Chen, Mu-Chen
;
Hsu, Chia-Lin
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
Using the loss aversion concept, this paper attempts to investigate the relationship between service quality and customers' post-dining behavioral intentions in the restaurant sector. Incorporating the DINESERV instrument, the results gained from a Chinese chain restaurant indicate that a decrease in service quality from the reference point (customer's expectation) will decrease the perceived service value and customer satisfaction, but that an increase in service quality may not have significant effects on these two behavioral constructs. Moreover, the behavior-related causal relationships underlying service quality suggest that perceived service value and attitudinal loyalty succeed in acting as mediating variables within the model. (C) 2009 Elsevier Ltd. All rights reserved.
Multilevel resistive switching in Ti/Cu(x)O/Pt memory devices
(2010-12-01)
Wang, Sheng-Yu
;
Huang, Chin-Wen
;
Lee, Dai-Ying
;
Tseng, Tseung-Yuen
;
Chang, Ting-Chang
The multilevel resistive switching (RS) behaviors of the Ti/Cu(x)O/Pt device were investigated by controlling the operated parameters of current and voltage bias in this study. We demonstrated that at least five-level memory states for data storage could be determined by controlling the current compliance, the span of voltage sweeping, and the amplitude of voltage pulse imposed on the memory device. During the dc voltage sweeping mode, not only the multilevel ON-states but also the multilevel OFF-states were achieved for the multilevel storage. The RS mechanism of the Ti/Cu(x)O/Pt device is proposed to be related to the formation/rupture of the conducting filaments, arising from the interfacial oxygen ion migration between the Ti top electrode and Cu(x)O films. Moreover, a possible conduction scenario for the multilevel RS behaviors is also suggested. Owing to all the multilevel memory states are distinguishable and possess the nondestructive readout property, it implies that the Ti/Cu(x)O/Pt device has the promising potential for the future multilevel-capability memory cell application. (c) 2010 American Institute of Physics. [doi:10.1063/1.3518514]