Browsing by Issue Date, starting with "2013-10-15"

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Empirical scaling laws and the aggregation of non-stationary data
(2013-10-15)
Chang, Lo-Bin
;
Geman, Stuart
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應用數學系
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Department of Applied Mathematics
Widely cited evidence for scaling (self-similarity) of the returns of stocks and other securities is inconsistent with virtually all currently-used models for price movements. In particular, state-of-the-art models provide for ubiquitous, irregular, and often times high-frequency fluctuations in volatility ("stochastic volatility"), both intraday and across the days, weeks, and years over which data is aggregated in demonstrations of self-similarity of returns. Stochastic volatility renders these models, which are based on variants and generalizations of random walks, incompatible with self-similarity. We show here that empirical evidence for self-similarity does not actually contradict the analytic lack of self-similarity in these models. The resolution of the mismatch between models and data can be traced to a statistical consequence of aggregating large amounts of non-stationary data. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.
Lysozyme-encapsulated gold nanocluster-based affinity mass spectrometry for pathogenic bacteria
(2013-10-15)
Chan, Po-Han
;
Wong, Song-Yi
;
Lin, Shu-Hsuan
;
Chen, Yu-Chie
;
應用化學系
RATIONALE: Bacterial infections can be difficult to treat and can lead to irreversible damage to patients if proper treatment is not provided in time. Additionally, the emerging threat from antibiotic-resistant bacterial strains makes medical treatment even more difficult. Thus, rapid identification of infected bacterial strains is essential to assist diagnostics and medical treatment. METHODS: Lysozymes are glycoside hydrolases that can bind with peptidoglycans on bacterial cell walls. In this work, we demonstrated that lysozyme-encapsulated gold nanoclusters (lysozyme-AuNCs) with red photoluminescence can be used as affinity probes to concentrate pathogenic bacteria. After bacteria had been probed by the lysozyme-AuNCs in a sample solution, the lysozyme-AuNC-bacteria conjugates were readily spun down at a low centrifugation speed. The red emission from the AuNCs on the conjugates could be visualized with the naked eye under illumination of ultraviolet light. The bacteria in the conjugates can be identified by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) combined with principal component analysis (PCA). RESULTS: We demonstrated that pathogenic bacteria including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, pandrug-resistant Acinetobacter baumannii, Staphylococcus aureus, Enterococcus faecalis, and vancomycin-resistant Enterococcus faecalis (VRE) can be readily concentrated by the lysozyme-AuNCs and distinguished by the results combining MALDI-MS and PCA. Additionally, the possibility of using the current approach to differentiate E. faecalis from VRE was also demonstrated. The lowest detection concentration for E. coli using the current approach is similar to 10(6) cells/mL. CONCLUSIONS: The results indicated that the lysozyme-AuNCs are effective affinity probes for Gram-positive and Gram-negative bacteria. By combining the results from MALDI-MS and PCA, different bacteria can be easily distinguished. The current approach can be potentially used to assist the identification of bacteria from biological fluids. Copyright (c) 2013 John Wiley & Sons, Ltd.
The role of the interface structure on the growth of nonpolar (10(1)over-bar0) and semipolar (11(2)over-bar(2)over-bar) ZnO on (112) LaAlO3 substrates
(2013-10-15)
Tian, Jr-Sheng
;
Wu, Yue-Han
;
Wang, Wei-Lin
;
Yen, Tzu-Chun
;
Ho, Yen-Teng
Growth of nonpolar (10 (1) over bar0) and semipolar (11 (2) over bar(2) over bar) ZnO on (112) LaAlO3 (LAO) substrates can be obtained by annealing the substrate surface in vacuum and oxygen ambient conditions prior to ZnO deposition, respectively. We investigated the origin of the two different growth relationships by inspecting their interface in atomic scale using high angle annular dark field scanning transmission electron microscopy. (10 (1) over bar0) ZnO was grown on flat (112)(LAO) surface due to the similar atomic configurations and small lattice mismatch between them at the interface, and (11 (2) over bar(2) over bar) ZnO was grown on a faceted surface with (001)(LAO) and (110)(LAO) facets on which accommodation growth of both (11 (2) over bar0) ZnO and (000 (1) over bar) ZnO are consistent with [1 (1) over bar 00](ZNO)//[1 (1) over bar0](LAO). (C) 2013 Elsevier B.V. All rights reserved.
Light trapping and near-unity solar absorption in a three-dimensional photonic-crystal
(2013-10-15)
Kuang, Ping
;
Deinega, Alexei
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Hsieh, Mei-Li
;
John, Sajeev
;
Lin, Shawn-Yu
We report what is to our knowledge the first observation of the effect of parallel-to-interface-refraction (PIR) in a three-dimensional, simple-cubic photonic-crystal. PIR is an acutely negative refraction of light inside a photonic-crystal, leading to light-bending by nearly 90 deg over broad wavelengths (.). The consequence is a longer path length of light in the medium and an improved light absorption beyond the Lambertian limit. As an illustration of the effect, we show near-unity total absorption (>= 98%) in lambda 520-620 nm and an average absorption of similar to 94% over lambda = 400-700 nm for our alpha-Si: H photonic-crystal sample of an equivalent bulk thickness of (t) over tilde = 450 nm. Furthermore, we have achieved an ultra-wide angular acceptance of light over theta = 0 degrees-80 degrees. This demonstration opens up a new door for light trapping and near-unity solar absorption over broad.s and wide angles. (C) 2013 Optical Society of America
Surface modification of commercial PtRu nanoparticles for methanol electro-oxidation
(2013-10-15)
Kuo, Che-Wei
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Lu, I-Te
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Chang, Li-Chung
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Hsieh, Yu-Chi
;
Tseng, Yuan-Chieh
The surfaces of commercially available PtRu nanoparticles (PtRu/C) have been successfully modified via a displacement reaction between the Ru atoms on the PtRu/C and the Pt ions in an aqueous hexachloroplatinic acid solution. The concentration of the hexachloroplatinic acid solution was deliberately formulated to allow for the formation of sub-monolayered Pt (Pt(1/16)) and monolayered Pt (Pt(1/8)) on the surface of PtRu/C. Material characterization, including X-ray diffraction patterns and transmission electron microscopy images, showed that the PtRu phases of the samples were identical but that the particle sizes increased slightly after the surface modification. Data from inductively coupled plasma mass spectrometry confirmed the deposition of Pt with negligible loss of Ru. X-ray absorption spectroscopy showed Pt-enriched surfaces, and the surface Pt content decreased in the order Pt(1/8) > Pt(1/16) > PtRu/C. Cyclic voltammetry and chronoamperometry were conducted for methanol electro-oxidation, and our results indicated impressive catalytic ability and carbon monoxide tolerance for Pt(1/16), followed by Pt(1/8) and PtRu/C. The mass activities of Pt(1/16) and Pt(118) increased 223% and 135% over that of PtRu/C. We attributed the observed improvements to the reduced amount of Ru on the PtRu surface, which resulted in an optimized PtRu ratio with enhanced catalytic ability. (C) 2013 Elsevier B.V. All rights reserved.
Genome-wide structural modelling of TCR-pMHC interactions
(2013-10-16)
Liu, I-Hsin
;
Lo, Yu-Shu
;
Yang, Jinn-Moon
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生物科技學系
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生物資訊及系統生物研究所
Background: The adaptive immune response is antigen-specific and triggered by pathogen recognition through T cells. Although the interactions and mechanisms of TCR-peptide-MHC (TCR-pMHC) have been studied over three decades, the biological basis for these processes remains controversial. As an increasing number of high-throughput binding epitopes and available TCR-pMHC complex structures, a fast genome-wide structural modelling of TCR-pMHC interactions is an emergent task for understanding immune interactions and developing peptide vaccines. Results: We first constructed the PPI matrices and iMatrix, using 621 non-redundant PPI interfaces and 398 non-redundant antigen-antibody interfaces, respectively, for modelling the MHC-peptide and TCR-peptide interfaces, respectively. The iMatrix consists of four knowledge-based scoring matrices to evaluate the hydrogen bonds and van der Waals forces between sidechains or backbones, respectively. The predicted energies of iMatrix are high correlated (Pearson's correlation coefficient is 0.6) to 70 experimental free energies on antigen-antibody interfaces. To further investigate iMatrix and PPI matrices, we inferred the 701,897 potential peptide antigens with significant statistic from 389 pathogen genomes and modelled the TCR-pMHC interactions using available TCR-pMHC complex structures. These identified peptide antigens keep hydrogen-bond energies and consensus interactions and our TCR-pMHC models can provide detailed interacting models and crucial binding regions. Conclusions: Experimental results demonstrate that our method can achieve high precision for predicting binding affinity and potential peptide antigens. We believe that iMatrix and our template-based method can be useful for the binding mechanisms of TCR-pMHC complexes and peptide vaccine designs.
膽固醇液晶顯示器及其驅動方法
(2013-10-16)
陳玉仙
;
陳皇銘
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劉勝發
;
江美昭
;
邱寶賢
一種膽固醇液晶顯示器包括：一第一基板，包括一第一配向層；一第二基板，包括一第二配向層；一膽固醇液晶層，配置於該第一及第二配向層之間；以及多個奈米級凸起物，其配置於該第一及第二配向層之其中一者的一表面，並位於該第一及第二配向層之其中該者與該膽固醇液晶層之間。
散熱基板與其製作方法
(2013-10-16)
吳耀銓
;
張岱民
;
邱郁珈
;
胡人立
本發明提供一種散熱基板與其製作方法。該散熱基板包括:一基板,其具有一表面;複數下凹區域,其形成於該表面;以及複數鑽石材料,其填充於該複數下凹區域。該散熱基板製作方法包括以下步驟:(a)在一基板的一表面形成複數下凹區域;以及(b)填充複數鑽石材料於該複數下凹區域。
METHOD FOR PRODUCING INDOLE DERIVATIVE
(2013-10-17)
Chiu Hsien-Tai
The present invention provides a method for in vitro producing an indole derivative in a one-pot reaction. The method for producing a rhamnosylated indolocarbazole compound includes the steps of transforming a plasmid carrying a gene encoding N-glycosyltransferase into a bacterial strain; expressing the gene encoding N-glycosyltransferase in the bacterial strain; lysing the bacterial strain to obtain a crude enzyme extract; and adding TDP-glucose, an indolocarbazole aglycone and a metal ion in the crude enzyme extract for performing an enzymatic reaction to form the rhamnosylated indolocarbazole compound. Alternatively, the method for producing an indole-3-carboxaldehyde analog includes the steps of transforming a plasmid carrying a gene encoding NokA of Nocardiopsis sp. K-252 into a bacterial strain; expressing the gene encoding NokA in the bacterial strain; lysing the bacterial strain to obtain a crude enzyme extract; and adding an L-tryptophan analog for performing an enzymatic reaction to form the indole-3-carboxaldehyde analog.
DECENTRALIZED STRUCTURED PEER-TO-PEER NETWORK AND LOAD BALANCING METHODS THEREOF
(2013-10-17)
HSU Chung-Yuan
;
WANG Kuochen
;
SHIH Hung-Cheng
An approach is provided for reassigning and sharing loads to peers with a same identity, which is based on a threshold. The peers are configured to store indexes of a key and to share the same loading (i.e., indexes) of the key to the peers with same secondary identities in different zones. The secondary identity is derived and has a modulo relationship with a first identity of the peer. The threshold indicates maximum number of indexes stored in each peer. Therefore, the loading are distributed evenly to peers in different zones, which achieves load balance to a decentralized structured peer-to-peer network.
RADIO SYSTEM AND OPERATING METHOD OF THE SAME
(2013-10-17)
WU Sau-Hsuan
;
KO Chun-Hsien
A radio system is provided. The radio system comprises primary devices, secondary devices, cognitive radio base stations and a data fusion center. The primary devices are licensed to use communication channels. The secondary devices acquire sensing reports of received signal strength, location and channel information of the primary devices. The cognitive radio base stations receive the sensing reports generated by the secondary devices through a control channel. The data fusion center receives the sensing reports from the cognitive radio base stations through a backbone network and performs a cooperative spectrum sensing process on the sensing reports to obtain primary device information with respect to the number, spectrum distribution and coverage area of the primary devices, wherein the primary device information is accessible by the secondary devices such that the secondary devices select one of the communication channels according to the primary device information to perform communications.
Structure deformation of indium oxide from nanoparticles into nanostructured polycrystalline films by in situ thermal radiation treatment
(2013-10-17)
Chong, Su Kong
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Azizan, Siti Nur Azieani
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Chan, Kee Wah
;
Hong-Quan Nguyen
;
Chiu, Wee Siong
A microstructure deformation of indium oxide (In2O3) nanoparticles by an in situ thermal radiation treatment in nitrous oxide plasma was investigated. The In2O3 nanoparticles were completely transformed into nanostructured In2O3 films upon 10 min of treatment time. The treated In2O3 nanoparticle sample showed improvement in crystallinity while maintaining a large surface area of nanostructure morphology. The direct transition optical absorption at higher photon energy and the electrical conductivity of the In2O3 nanoparticles were significantly enhanced by the treatment.
Sulfonated graphene oxide/Nafion composite membranes for high-performance direct methanol fuel cells
(2013-10-17)
Chien, Hung-Chung
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Tsai, Li-Duan
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Huang, Chiu-Ping
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Kang, Chi-yun
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Lin, Jiunn-Nan
An easy and effective method for producing low methanol-crossover membranes is developed by dispersing sulfonated graphene oxide (SGO) into a Nafion matrix. A SGO/Nafion mixture with low SGO content exhibits unique viscosity behavior and allows for better SGO dispersion within the Nafion. After film casting, the composite membranes show lower methanol and water uptakes, a reduced swelling ratio, improved proton conductivity in low relative humidity, and extremely high methanol selectivity, which can be implemented in direct methanol fuel cells (DMFCs). The regular backbone of the composite membrane shows a higher storage modulus, increased a-relaxation (transition temperature), and improved tolerance to pressure during membrane electrode assembly (MEA). The small angle X-ray spectra indicate the shrinkage of the ionic clusters in the composite membranes, which thus reduce methanol crossover. The hybrid membranes applied to DMFCs demonstrate performances superior to that of the commercial Nafion 115 in 1 M and 5 M methanol solutions. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
An in situ fabrication process for highly electrical conductive polyimide/MWCNT composite films using 2,6-diaminoanthraquinone
(2013-10-18)
Huang, Yi-Chia
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Lin, June-Hua
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Tseng, I-Hsiang
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Lo, An-Ya
;
Lo, Teng-Yuan
We present a valuable in situ fabrication process for synthesizing high electrical conductive polyimide/multiwalled carbon nanotube (PI/MWCNT) composite films. The success of this process was achieved the addition of 2,6-diaminoanthraquinone (DAAQ). The DAAQ is not only an excellent dispersion agent to stably disperse pristine MWCNTs in solvent but also a monomer to directly synthesize PI. The strong interaction between DAAQ with MWCNT was verified by FTIR, UV-Vis, Raman, and fluorescence spectra. The highest value of electrical conductivity of 55.6 S/cm are achieved by the PI composite containing 40 wt.% of MWCNT. Moreover, the electrical conductivity of this film further enhanced to 106 S/cm after the thermal compression process. The MWCNT content at the percolation threshold of conductivity is 0.50 wt.% (or 0.32 vol.%) and the critical exponent is equal to 2.52. The developed in situ fabrication process through DAAQ-derived molecules can also be applied to synthesize other polymers requiring diamine structure. (C) 2013 Published by Elsevier Ltd.
Synthesis and Molecular Properties of Four Isomeric Dialkylated Angular-Shaped Naphthodithiophenes
(2013-10-18)
Cheng, Sheng-Wen
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Chiou, De-Yang
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Lai, Yu-Ying
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Yu, Ruo-Han
;
Lee, Chia-Hao
A new strategy to synthesize 4,9- and 5,10-dialkylated alpha-aNDTs as well as 4,9- and 5,10-dialkylated beta-aNDTs is described. Four isomeric precursors with different dithienyl-ene-diyne arrangements undergo base-induced double 6 pi-cyclization to construct the central naphthalene cores, leading to the formation of the regiospecific products. These 2,7-distannylated dialkylated aNDT-based monomers can be used for Stille cross-coupling to produce promising conjugated materials for various optoelectronic applications.
Tandem Isomerization and C-H Activation: Regioselective Hydroheteroarylation of Allylarenes
(2013-10-18)
Lee, Wei-Chih
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Wang, Chun-Han
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Lin, Yung-Huei
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Shih, Wei-Chun
;
Ong, Tiow-Gan
The first Ni-promoted prototype reaction based on the tandem C-H activation of heteroarenes with alkene isomerization is demonstrated, leading to the branched hydroheteroarylation products. Simultaneously, the reaction selectivity can be chemically switched to linear adducts through Ni-Al tandem catalysis.
Crystal Structures of Vertebrate Dihydropyrimidinase and Complexes from Tetraodon nigroviridis with Lysine Carbamylation METAL AND STRUCTURAL REQUIREMENTS FOR POST-TRANSLATIONAL MODIFICATION AND FUNCTION
(2013-10-18)
Hsieh, Yin-Cheng
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Chen, Mei-Chun
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Hsu, Ching-Chen
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Chan, Sunney I.
;
Yang, Yuh-Shyong
Lysine carbamylation, a post-translational modification, facilitates metal coordination for specific enzymatic activities. We have determined structures of the vertebrate dihydropyrimidinase from Tetraodon nigroviridis (TnDhp) in various states: the apoenzyme as well as two forms of the holoenzyme with one and two metals at the catalytic site. The essential active-site structural requirements have been identified for the possible existence of four metal-mediated stages of lysine carbamylation. Only one metal is sufficient for stabilizing lysine carbamylation; however, the post-translational lysine carbamylation facilitates additional metal coordination for the regulation of specific enzymatic activities through controlling the conformations of two dynamic loops, Ala(69)-Arg(74) and Met(158)-Met(165), located in the tunnel for the substrate entrance. The substrate/product tunnel is in the open form in the apo-TnDhp, in the intermediate state in the monometal TnDhp, and in the closed form in the dimetal TnDhp structure, respectively. Structural comparison also suggests that the C-terminal tail plays a role in the enzymatic function through interactions with the Ala(69)-Arg(74) dynamic loop. In addition, the structures of the dimetal TnDhp in complexes with hydantoin, N-carbamyl--alanine, and N-carbamyl--amino isobutyrate as well as apo-TnDhp in complex with a product analog, N-(2-acetamido)-iminodiacetic acid, have been determined. These structural results illustrate how a protein exploits unique lysines and the metal distribution to accomplish lysine carbamylation as well as subsequent enzymatic functions.
Tuning Reactivity of Glycosyl Imidinium Intermediate for 2-Azido-2-deoxyglycosyl Donors in alpha-Glycosidic Bond Formation
(2013-10-18)
Ingle, Arun B.
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Chao, Chin-Sheng
;
Hung, Wei-Cheng
;
Mong, Kwok-Kong Tony
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應用化學系
The chemical properties of nucleophile additives were investigated in a modulated glycosylation context. N-Formylmorpholine (NFM) was found to be an effective modulator for glycosylation with less reactive 2-azido-2-deoxythioglucosyl and thiogalactosyl donors.
快閃音樂會　古典樂上街頭
(2013-10-20)
李孟東
;
Department of Communication and Technology
;
傳播與科技學系
快閃（flashmob）一詞最早源於二○○三年的美國紐約曼哈頓地區，並且由美洲大陸傳播至歐洲、亞洲等地區。拜網際網路和社群網站的蓬勃發展所賜，街頭快閃行動已有將近十年的發展，並且成為一種獨特的文化風格。而快閃音樂會正是古典音樂與快閃運動結合並誕生出另一種獨特的音樂表演形式。
選秀節目　蔓延兒童圈
(2013-10-20)
黃筱雯
;
Department of Communication and Technology
;
傳播與科技學系
選秀節目蓬勃發展，兒童參加選秀節目的機會也越來越多。例如：《超級偶像七》中的張龍和《超級接班人》節目裡的PopCorn都是節目中年紀最小的參賽者。兒童參加選秀節目，對於電視台、觀眾、參賽者本身有什麼樣的影響呢？