Browsing by Issue Date, starting with "2015-06-15"

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Ablation of androgen receptor gene triggers right ventricular outflow tract ventricular tachycardia
(2015-06-15)
Tsai, Wen-Chin
;
Lu, Yen-Yu
;
Chen, Yao-Chang
;
Chang, Chien-Jung
;
Kao, Yu-Hsun
Background: Sex hormones and calcium (Ca2+) regulation play roles in the pathophysiology of ventricular tachycardia from right ventricular outflow tract (RVOT). The purpose of this study was to evaluate whether androgen receptor knockout (ARKO) can increase RVOT arrhythmogenesis through modulating RVOT electrophysiology and Ca2+ homeostasis. Methods: Conventional microelectrodes were used to study the action potential (AP) in RVOT tissues prepared from wild type (WT) and ARKO mice (aged 6-10 months) before and after caffeine (1 mM), isoproterenol (1 mu M), adenosine (10 mu M) and flecainide (5 mu M) administration. The Fluo-3 fluorescence Ca2+ imaging with confocal microscopy and western blots were used to investigate intracellular Ca2+ (Ca-i(2+)) transients, Ca2+ sparks, and the expressions of ionic channel proteins in ARKO and WT RVOT myocytes. Results: We found that ARKO RVOTs (n = 13) had longer AP duration, faster burst firing (5.4 +/- 0.7 vs. 3.4 +/- 0.7 Hz, P < 0.05), and higher incidence of early afterdepolarizations (82% vs. 8%, P < 0.001) than WT RVOTs (n = 11). Adenosine and flecainide can suppress caffeine-or isoproterenol-induced spontaneous rates and burst firing in WT RVOTs, but not in ARKO RVOTs. ARKO RVOT myocytes had a higher frequency (7.7 +/- 2.8 vs. 1.3 +/- 0.4 spark/mm/s, P < 0.05) and incidence (89% vs. 47%, P < 0.05) of Ca2+ sparks, and greater expressions of Cav1.2, NCX, phosphorylated RyR (s2814), phosphorylated phospholamban (Thr17), CAMKII and GRK2 than WT RVOT myocytes. However, ARKO andWT RVOT myocytes exhibit similar Ca-i(2+) transients and SR Ca2+ content, and less expression of calsequestrin. Conclusions: ARKO changes RVOT electrophysiology and Ca2+ homeostasis with increased ventricular arrhythmogenesis. (C) 2015 Elsevier Ireland Ltd. All rights reserved.
Exploring the influence of high order transverse modes on the temporal dynamics in an optically pumped mode-locked semiconductor disk laser
(2015-06-15)
Tsou, C. H.
;
Liang, H. C.
;
Wen, C. P.
;
Su, K. W.
;
Huang, K. F.
We quantitatively investigate the influence of high-order transverse modes on the self-mode locking (SML) in an optically pumped semiconductor laser (OPSL) with a nearly hemispherical cavity. A physical aperture is inserted into the cavity to manipulate the excitation of high-order transverse modes. Experimental measurements reveal that the laser is operated in a well-behaved SML state with the existence of the TEM0,0 mode and the first high-order transverse mode. While more high-order transverse modes are excited, it is found that the pulse train is modulated by more beating frequencies of transverse modes. The temporal behavior becomes the random dynamics when too many high-order transverse modes are excited. We observe that the temporal trace exhibits an intermittent mode-locked state in the absence of high-order transverse modes. (C) 2015 Optical Society of America
Reaction-based epoxide fluorescent probe for in vivo visualization of hydrogen sulfide
(2015-06-15)
Sathyadevi, Palanisamy
;
Chen, Yu-Jen
;
Wu, Shou-Cheng
;
Chen, Yen-Hao
;
Wang, Yun-Ming
Hydrogen sulfide (H2S) has emerged as the most important biosynthetic gasotransmitters along with nitric oxide (NO) and carbon monoxide (CO). In this study, we report the design and the synthesis of a new epoxide fluorescent probe 7-glycidyloxy-9-(2-glycidyloxycarbonylphenyl)-2-xanthone (FEPO) for use in in vivo visualization of hydrogen sulfide. The probe employs a fluorescein as a fluorophore, and is equipped with an operating epoxide unit. FEPO functions via epoxide ring opening upon nucleophilic attack of H2S. This ring opening strategy may open a new avenue for the development of various H2S fluorescent sensors. FEPO showed high selectivity and high sensitivity for H2S. FEPO\'s cytotoxicity was tested using MTT (2-(4,5-dimethyl-2-thiazolyl)-3,5-diphenyl-2H-tetrazolium bromide) assay. Furthermore, the use of confocal imaging of H2S and in vivo imaging in live zebra fish demonstrated FEPO\'s potential biological applications. We anticipate that, owing to their ideal properties, probes of this type will find great uses in exploring the role of H2S in biology. (C) 2015 Elsevier B.V. All rights reserved.
Label-Free Fluorescent Copper Nanoclusters for Genotyping of Deletion and Duplication of Duchenne Muscular Dystrophy
(2015-06-16)
Chen, Chung-An
;
Wang, Chun-Chi
;
Jong, Yuh-Jyh
;
Wu, Shou-Mei
;
生物科技學院
Real applications in clinical diagnosis of label-free fluorescent copper nanoclusters (CuNCs) are demonstrated. Double-strand DNA (dsDNA) can act as an effective template for the formation of CuNCs, which can be used to distinguish the deletion or duplication genotypes of Duchenne muscular dystrophy (DMD) due to different fluorescent intensities. After PCR, the DMD amplicons reacted with copper ion by reduction of ascorbic acid and generated fluorescence. The exons of the DMD gene were taken as the model analytes for genetic diagnosis. In this sensing system, the deletion type does not show fluorescence; on the other hand, the duplication type emits higher fluorescence than normal type. Parameters of this sensing system were optimized, including PCR conditions, levels of copper ion and ascorbate, and reaction time. The DMD-dominated exons 45, 46, and 47 were detected, and the method was applied to six samples of DMD patients. The results were consistent with those of the multiplex ligation-dependent probe amplification method. This strategy was feasible to detect all exons of this disease.
Anchor-based classification and type-C inhibitors for tyrosine kinases
(2015-06-16)
Hsu, Kai-Cheng
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Sung, Tzu-Ying
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Lin, Chih-Ta
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Chiu, Yi-Yuan
;
Hsu, John T. -A.
Tyrosine kinases regulate various biological processes and are drug targets for cancers. At present, the design of selective and anti-resistant inhibitors of kinases is an emergent task. Here, we inferred specific site-moiety maps containing two specific anchors to uncover a new binding pocket in the C-terminal hinge region by docking 4,680 kinase inhibitors into 51 protein kinases, and this finding provides an opportunity for the development of kinase inhibitors with high selectivity and anti-drug resistance. We present an anchor-based classification for tyrosine kinases and discover two type-C inhibitors, namely rosmarinic acid (RA) and EGCG, which occupy two and one specific anchors, respectively, by screening 118,759 natural compounds. Our profiling reveals that RA and EGCG selectively inhibit 3% (EGFR and SYK) and 14% of 64 kinases, respectively. According to the guide of our anchor model, we synthesized three RA derivatives with better potency. These type-C inhibitors are able to maintain activities for drug-resistant EGFR and decrease the invasion ability of breast cancer cells. Our results show that the type-C inhibitors occupying a new pocket are promising for cancer treatments due to their kinase selectivity and anti-drug resistance.
High-Performance and Stable Gel-State Dye-Sensitized Solar Cells Using Anodic TiO2 Nanotube Arrays and Polymer-Based Gel Electrolytes
(2015-06-17)
Seidalilir, Zahra
;
Malekfar, Rasoul
;
Wu, Hui-Ping
;
Shiu, Jia-Wei
;
Diau, Eric Wei-Guang
Highly ordered and vertically oriented TiO2 nanotube (NT) arrays were synthesized with potentiostatic anodization of Ti foil and applied to fabricate gel-state dye-sensitized solar cells (DSSCs). The open structure of the TiO2 NT facilitates the infiltration of the gel-state electrolyte; their one-dimensional structural feature provides effective charge transport. TiO2 NTs of length L = 15-35 mu m were produced on anodization for periods of t = 5-15 h at a constant voltage of 60 V, and sensitized with N719 for photovoltaic characterization. A commercially available copolymer, poly(methyl methacrylate-co-ethyl acrylate) (PMMA-EA) served as a gelling agent to prepare a polymer-gel electrolyte (PGE) for DSSC applications. The PGE as prepared exhibited a maximum conductivity of 4.58 mS cm(-1) with PMMA-EA (7 wt %). The phase transition temperature (T-p) of the PGE containing PMMA-EA at varied concentrations was determined on the basis of the viscosities measured at varied temperatures. T-p increased with increasing concentration of PMMA-EA. An NT-DSSC with L = 30 mu m assembled using a PGE containing PMMA-EA (7 wt %) exhibited an overall power conversion efficiency (PCE) of 6.9%, which is comparable with that of a corresponding liquid-type device, PCE = 7.1%. Moreover, the gel-state NT-DSSC exhibited excellent thermal and light-soaking enduring stability: the best device retained similar to 90% of its initial efficiency after 1000 h under 1 sun of illumination at 50 degrees C, whereas its liquid-state counterpart decayed appreciably after light soaking for 500 h.
Intersystem Crossing Pathway in Quinoline-Pyrazole Isomerism: A Time-Dependent Density Functional Theory Study on Excited-State Intramolecular Proton Transfer
(2015-06-18)
Liu, Yu-Hui
;
Lan, Sheng-Cheng
;
Zhu, Chaoyuan
;
Lin, Sheng-Hsien
;
應用化學系分子科學碩博班
The dynamics of the excited-state intramolecular proton-transfer (ESIPT) reaction of quinoline pyrazole (QP) isomers, designated as QP-I and QP-II, has been investigated by means of time-dependent density functional theory (TDDFT). A lower barrier has been found in the potential energy curve for the lowest singlet excited state (S-1) along the proton-transfer coordinate of QP-II compared with that of QP-I; however, this is at variance with a recent experimental report [J. Phys. Chem. A 2010, 114, 7886-7891], in which the authors proposed that the ESIPT reaction would only proceed in QP-I due to the absence of a PT emission for QP-II. Therefore, several deactivating pathways have been investigated to determine whether fluorescence quenching occurs in the PT form of QP-II (PT-II). The Si state of PT-II has n pi* character, which is a well-known dark state. Moreover, the energy gap between the S-1 and T-2 states is only 0.29 eV, implying that an intersystem crossing (ISC) process would occur rapidly following the ESIPT reaction. Therefore, it is demonstrated that the ESIPT could successfully proceed in QP-II and that the PT emission would be quenched by the ISC process.
MULTI-PORT SRAM WITH SHARED WRITE BIT-LINE ARCHITECTURE AND SELECTIVE READ PATH FOR LOW POWER OPERATION
(2015-06-18)
HWANG Wei
;
WANG Dao-Ping
A multi-port SRAM with shared write bit-line architecture and selective read path for low power operation includes a first memory cell, a second memory cell, and a common switch set. The second memory cell makes use of the common switch set to share the A-port write bit-line and the B-port write bit-line with the first memory cell so as to reduce half write bit-line number and reduce the write current consumption caused by pre-charging the bit-line to VDD. It also provides a selective read path structure for read operation. Replacing the ground connection in the read port with a virtual VSS controlled by a Y-select signal reduces read-port current consumption.
Effect of phosphate surface pretreatment on corrosion resistance and adhesion of PI coating on Mg-5 wt.% Sn alloy
(2015-06-18)
Lee, Hsiao-Chien
;
Huang, Yi-Chia
;
Liu, Tzeng-Feng
;
Whang, Wha-Tzong
;
Chao, Chuen-Guang
In this study, phosphate surface pretreatment (PSPT) and poly[pyromellitic dianhydride-co-4,4MODIFIER LETTER PRIME-oxydianiline] polyimide (PMDA-ODA PI) coating were used to provide corrosion protection for Mg-5 wt.% Sn alloy. PSPT enhanced the adhesion of PI coating by mechanical interlocking and chemical anchoring. Surface roughness was increased and provided stronger mechanical interlocking. Phosphates were formed on the alloy surface to act as anchor groups. Energy dispersive X-rayspectrometer and X-ray photoelectron spectroscopy results indicated that bonds formed between anchor groups and PI coating. The bonds provided chemical anchoring and enhanced the adhesion of PI coating. The increase of corrosion resistance of PI coating on Mg-5 wt.% Sn alloy (E-corr = -0.86V/SCE, [GRAPHICS] mu A cm(-2) and corrosion rate far less than [GRAPHICS] showed the bonds were stable enough to stand the attack of electrolyte and inhibit the electrochemical reaction at the interface.
Highly Selective Dissociation of a Peptide Bond Following Excitation of Core Electrons
(2015-06-18)
Lin, Yi-Shiue
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Tsai, Cheng-Cheng
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Lin, Huei-Ru
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Hsieh, Tsung-Lin
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Chen, Jien-Lian
The controlled breaking of a specific chemical bond with photons in complex molecules remains a major challenge in chemistry. In principle, using the K-edge absorption of a particular atomic element, one might excite selectively a specific atomic entity in a molecule. We report here highly selective dissociation of the peptide bonds in N-methylformamide and N-methylacetamide on tuning the X-ray wavelength to the K-edge absorption of the atoms connected to (or near) the peptide bond. The high selectivity (56-71%) of this cleavage arises from the large energy shift of X-ray absorption, a large overlap of the Is orbital and the valence pi* orbital that is highly localized on a peptide bond with antibonding character, and the relatively low bond energy of the peptide bonds. These characteristics indicate that the high selectivity on bond dissociation following core excitation could be a general feature for molecules containing peptide bonds.
OPTIMAL DYNAMIC SEAM ADJUSTMENT SYSTEM AND METHOD FOR IMAGE STITCHING
(2015-06-18)
GUO Jiun-In
;
CHANG Hsiu-Cheng
;
CHIEN Cheng-An
;
HUANG Kai-Chen
An optimal dynamic seam adjustment system for image stitching includes an image obtaining module, a feature difference calculation module and a dynamic seam module. The image obtaining module obtains at least two images to be stitched, which have at least one overlapping area divided into a plurality of pixels arranged in a plurality of pixel columns and a plurality of pixel rows. The feature difference calculation module calculates a feature difference value for each pixel within the overlapping area. The dynamic seam module establishes a plurality of dynamic seam routes started from a top end of the overlapping area, so as to find an optimal dynamic seam route based on the feature difference value, wherein each dynamic seam route is composed of a plurality of pixels.
可適性計算方法與架構
(2015-06-21)
張良正
;
陳宇文
;
蔡瑞彬
1.一種用於獲得地下水流之一性質的方法，包括以下步驟：(a)用一方程式集合來描述該地下水流的一守恆量，該方程式集合具有與該守恆量相關的至少一方程式與代表該性質的至少一變數；(b)對該方程式集合進行一一致性分析，以檢驗該至少一方程式與該至少一變數之一致性，並得一求解順序，且定義多個空間網格與多個節點，並依該等節點將該方程式集合與該至少一變數，離散化成為一離散方程組；以及(c)依據該求解順序，求解該離散方程組。
利用下壓方式組裝之三維斜面微結構
(2015-06-21)
邱一
;
施錫富
;
林健安
一種利用下壓方式組裝之三維斜面微結構，其包括：一基底層；一斜面主體，其設置於該基底層上，該斜面主體兩側相對應各設有一第一凸出部，該斜面主體底部設有一第一推墊，該第一推墊下方處前述基底層設有一第一容置空間用以容納該第一推墊，且該斜面主體底部設有向兩側水平延伸之第一扭轉樑；以及一U型支撐架，其設置於該基底層上，該U型支撐架之兩支架部內側相對應各設有一第二凸出部，該U型支撐架底部設有一第二推墊，該第二推墊下方處前述基底層設有一第二容置空間用以容納該第二推墊，且該U型支撐架底部設有向兩側水平延伸之第二扭轉樑；俾藉，下壓推動該第一推墊及第二推墊，使該斜面主體經由第一扭轉樑為軸心轉動，該U型支撐架經由第二扭轉樑為軸心轉動，並藉由該些第一凸出部與第二凸出部互相卡扣固定形成一三維斜面微結構。
石墨氧化物製備方法
(2015-06-21)
韋光華
;
鄧文成
一種石墨氧化物之製備方法，包含下列步驟：提供一電漿電解裝置，其中該電漿電解裝置具有一電解液，該電解液之pH為介於11與17之間，以及該電漿電解裝置之一陰極為一石墨電極；以及提供一陰極電流於該石墨電極，使該石墨電極進行一電漿電解反應以得到石墨氧化物。
使用車用電源線傳輸控制信號之設備
(2015-06-21)
曾煜輝
;
蘇朝琴
;
何盈杰
一種使用車用電源線傳輸控制信號之設備，包含：一發送端信號收發實體連接介面，係電性連接一車用電源線；一控制信號發送器，係電性連接該發送端信號收發實體連接介面，藉以電性連接該車用電源線；複數個接收端信號收發實體連接介面，係電性連接該車用電源線；複數個控制信號接收器，各控制信號接收器係與該複數個接收端信號收發實體連接介面對應電性連接，藉以電性連接該車用電源線，且各控制信號接收器係分別電性連接一車用電子設備；其中，該控制信號發送器係經由該車用電源線以一寬頻數位通信傳輸技術將一組二進位數位信號傳送至該複數個控制信號接收器其中之一，藉以控制電性連接該控制信號接收器之車用電子設備。
基於語音情感辨識之音樂播放系統及其方法
(2015-06-21)
宋開泰
;
史威德
一種音樂播放系統，適用在基於語音情感辨識以選擇曲目播放，包括：一第一資料庫，儲存多首歌曲及該些歌曲映射在一情緒座標圖上的歌曲情緒座標；一第二資料庫，儲存情緒辨識參數；一收音裝置，接收一語音資料；一控制裝置，連接至該第一資料庫、該第二資料庫及該收音裝置，分析該語音資料的頻率，透過該第二資料庫進行比對，獲取該語音資料映射在該情緒座標圖之上的一當前情緒座標，接著接收一目標情緒座標之設定，在該當前情緒座標及該目標情緒座標相連的一喚醒直線上，找尋該第一資料庫中最接近該喚醒直線的至少一特定歌曲情緒座標。
交大e-News第188期-立足交大點亮世界
(2015-06-22)
國立交通大學秘書室
;
Secretariat
Phosphorus-Doped p-n Homojunction ZnO Nanowires: Growth Kinetics in Liquid and Their Optoelectronic Properties
(2015-06-23)
Lee, Wei-Che
;
Chen, Jul-Yuan
;
Huang, Chun-Wei
;
Chiu, Chung-Hua
;
Lin, Ting-Yi
For wide-ranging applications in nanoscale electronic devices, durable and reproducible p-type nanostructures are essential. In this work, simple ZnO nano-wire (NW) p-n homojunctions were grown using a two-step hydrothermal synthesis method. P2O5 served as a doping source to obtain p-type ZnO NW\'s. The morphology of the ZnO NW arrays was examined using field emission scanning electron microscopy. The high-resolution transmission electron microscopy (HRTEM) image indicated that the ZnO NW p-n homojunction is single-crystalline with a < 0001 > growth direction. The distribution of P element was analyzed using energy-dispersive spectroscopy. The dynamic growth observation was conducted using liquid in situ TEM to investigate the ZnO nucleation and growth mechanism. We divided the ZnO nanocrystal precipitation into three processes. Whether two adjacent particles grow stably or not was found to be related to the distance. Moreover, the temperature-dependent photoluminescence spectra revealed that two extra emission peaks located at 416 and 435 nm were emitted from the ZnO NW p-n homojunction, which resulted from donor-acceptor recombination. In addition, the electron transport properties confirmed the rectification behavior of the multi ZnO NW p-n homojunctions. The turn-on voltage and the current were approximately 2.8 V and 10(-4) to 10(-5) A, respectively, under forward bias. The results indicate the potential application of ZnO NW p-n homojunctions as nanoscale light-emitting diodes.
Tailoring low-dimensional structures of bismuth on monolayer epitaxial graphene
(2015-06-23)
Chen, H. -H.
;
Su, S. H.
;
Chang, S. -L.
;
Cheng, B. -Y.
;
Chen, S. W.
To improve graphene-based multifunctional devices at nanoscale, a stepwise and controllable fabrication procedure must be elucidated. Here, a series of structural transition of bismuth (Bi) adatoms, adsorbed on monolayer epitaxial graphene (MEG), is explored at room temperature. Bi adatoms undergo a structural transition from one-dimensional (1D) linear structures to two-dimensional (2D) triangular islands and such 2D growth mode is affected by the corrugated substrate. Upon Bi deposition, a little charge transfer occurs and a characteristic peak can be observed in the tunneling spectrum, reflecting the distinctive electronic structure of the Bi adatoms. When annealed to similar to 500 K, 2D triangular Bi islands aggregate into Bi nanoclusters (NCs) of uniform size. A well-controlled fabrication method is thus demonstrated. The approaches adopted herein provide perspectives for fabricating and characterizing periodic networks on MEG and related systems, which are useful in realizing graphene-based electronic, energy, sensor and spintronic devices.
Photon doughnut-shaped pair for easy production of entangled photon pairs
(2015-06-29)
Lo, Hsin-Pin
;
Yabushita, Atsushi
;
Kobayashi, Takayoshi
;
電子物理學系
;
Department of Electrophysics
Parametric down-conversion in a nonlinear crystal-generated photon pair in which photons have orthogonal polarization. The pair was emitted in a cone shape for each polarization and collimated by a lens to be doughnut shaped. The doughnutlike photon pair runs collinear to the pump laser. The group delay and walk-off between the orthogonal polarization photons in the pair were compensated passing through a half-wave plate and a nonlinear crystal. Then, the photon doughnut pair was coupled into a 1 x 2 fiber together with a pump laser, i.e., the intense pump laser was used as a guide for alignment. After the alignment was finished, a cut filter was inserted in the optical path to cut the pump laser transmitting the photon doughnut pair. The coincidence measurement of the output of the 1 x 2 fiber showed that the photon pairs are entangled in polarization.