Browsing by Issue Date, starting with "2014-01-06"

Now showing 1 - 20 of 27812

Ba3TM2Se9 (TM = Nb, Ta): Synthesis and Characterization of New Polyselenides
(2014-01-06)
Chung, Ming-Yan
;
Lee, Chi-Shen
;
應用化學系
;
Department of Applied Chemistry
New ternary polyselenides Ba3TM2Se9 (TM = Nb, Ta) were synthesized through a solid-state reaction, and their structures were characterized using single-crystal X-ray diffraction. These compounds crystallized into a new structural type with a monoclinic space group P2(1)/c. The structures were constructed from distorted, close-packed layers of (3)(infinity)[BaSe3](3.33-) that incorporated TM atoms at octahedral sites and contained [(TM5+)(2)(Se2-)(7)(Se-2(2-))] units. Diffuse reflectance spectra and electronic resistivity measurements indicated semiconducting properties and optical band gaps of 1.3 eV for Ba3Nb2Se9 and 1.6 eV for Ba3Ta2Se9. Raman spectra were used to investigate the interatomic interactions. Calculations of the electronic structure verified the semiconducting behavior and bonding interaction of short Se-Se contacts.
Constraining dark matter capture and annihilation cross sections by searching for neutrino signature from the Earth's core
(2014-01-06)
Lee, Fei-Fan
;
Lin, Guey-Lin
;
Tsai, Yue-Lin Sming
;
物理研究所
;
Institute of Physics
We study the sensitivity of IceCube/DeepCore detector to dark matter annihilations in the Earth's core. We focus on annihilation modes chi chi -> nu(nu) over cap, tau(+)tau(-), h (h) over cap, and W+W-. Both track and cascade events are considered in our analysis. By fixing the dark matter annihilation cross section at some nominal values, we study the sensitivity of the IceCube/DeepCore detector to dark matter spin- independent cross section sigma(SI)(p) for m(chi) ranging from few tens of GeV to 10 TeV. This sensitivity is compared with the existing IceCube 79-string constraint on the same cross section, which was obtained by searching for dark matter annihilations in the Sun. We compare this sensitivity to dark matter direct detection results as well, in particular the XENON100 (2012) limit and the parameter regions preferred by DAMA and CRESST- II experiments. We also present IceCube/DeepCore sensitivity to hs.i as a function of m(chi) by fixing sigma(SI)(p) at XENON100 (2012) and XENON1T limits, respectively. This sensitivity is compared with the preferred dark matter parameter range derived from the combined fitting to PAMELA and AMS02 positron fraction data. We conclude that the search for dark matter annihilations in the Earth's core provides competitive constraints on sigma(SI)(p) and in the case of low- mass dark matter. Particularly, the expected constraint on sigma(SI)(p) for 5 years of data taking in IceCube/DeepCore is more stringent than the current IceCube 79- string limit mentioned above.
交大e-News第155期
(2014-01-06)
Secretariat
;
國立交通大學秘書室
Enhanced processability of MWCNT through surface treatment by octa(phenol) polyhedral oligomeric silsesquioxane nano-crosslinking
(2014-01-06)
Omrani, Abdollah
;
Yen, Ying-Chieh
;
Cheng, Chih-Chia
;
Chang, Feng-Chih
;
應用化學系
A facile method was developed to prepare MWCNT/POSS nanocomposites by direct esterification between carboxylic acid functionalized MWCNT and octa(phenol) octasilsesquioxane. Completeness of the MWCNT surface modification was confirmed by FT-IR. The hybrid nano-MWCNT-OP-POSS composite structure and properties was characterized using DSC, TGA, optical microscopy, WAXD, and AFM. The results indicated the solubility and processability of MWCNT-COOH improved because of OP-POSS grafting on MWCNT surface. The T-g and thermal stability of the nanocomposites was higher than that of the OP-POSS as a result of the cross-linking reaction. AFM observations revealed that the nanocomponents were reacted in a homogeneous phase at nanoscale level. (C) 2013 Elsevier B.V. All rights reserved.
One-pot formation of fluorescent gamma-lactams having an alpha-phosphorus ylide moiety through three-component alpha(delta ')-Michael reactions of phosphines with an enyne and N-tosyl aldimines
(2014-01-07)
Lin, Yu-Wei
;
Deng, Jie-Cheng
;
Hsieh, You-Zung
;
Chuang, Shih-Ching
;
應用化學系
We demonstrate a straightforward synthesis of gamma-lactams possessing an a-phosphorus Aide moiety from assembly of phosphines, N-tosyl aldimines and an enyne through an initial alpha(delta')-attack of phosphines to an enyne in up to 79% yield. The investigated multicomponent reaction tolerates a variety of triaryl-phosphines and electron-poor aldimines to give gamma-lactams in one pot. One of the lactams, with the tri(p-tol)phosphine and 4-cyanophenyl moiety, exhibits fluorescence emission at 447 nm with a quantum yield of 0.11.
Drug-carrying contact lens and method for fabricating the same
(2014-01-07)
Liu Dean-Mo
;
Liu Pei-Ling
The present invention discloses a drug-carrying contact lens and a method for fabricating the same. The drug-carrying contact lens comprises a contact lens containing at least one amphiphatic hybrid nanocarrier carrying drug molecules. According to the heat or light sensitivity of the drug molecule, the present invention respectively fabricates an encapsulation-type drug-carrying contact lens and a drug-soaking type drug-carrying contact lens. The present invention uses a highly-biocompatible amphiphatic hybrid nanocarriers having superior drug encapsulation capability to wrap the drug molecules. Thereby, the drug molecules are uniformly distributed in the contact lens and can be gradually and locally released to the eye of the user wearing the contact lens. Therefore, the present invention can prevent or cure ocular diseases with the loss and side effects of the drug being reduced.
Broad Ranges and Fast Responses of Single-Component Blue-Phase Liquid Crystals Containing Banana-Shaped 1,3,4-Oxadiazole Cores
(2014-01-08)
Chiang, I-Hung
;
Long, Chun-Ji
;
Lin, Hsin-Chieh
;
Chuang, Wei-Tsung
;
Lee, Jey-Jau
In this study, we synthesized two novel 1,3,4-oxadiazole-based bent-core liquid crystals (OXD7*, OXD5B7F*) containing a chiral tail that display broad ranges of the blue phase III (34 and 7 K, respectively); we characterized them using polarized optical microscopy, differential scanning calorimetry, and circular dichroism. The electro-optical responses of both of these liquid crystals are much faster than those of previously reported single-component blue-phase liquid crystals. To optimize its electro-optical performance, we mixed OXD7* (the blue-phase range of which is broader than that of OXD5B7F*) with its analogue OXD6 (at weight ratios of 6:4 and 4:6). We also performed molecular modeling of single-component BPLCs (OXD7* and OXD5B7F*) to analyze the possible parameters affecting their blue phase ranges.
Overexpression of Endothelin 1 Triggers Hepatocarcinogenesis in Zebrafish and Promotes Cell Proliferation and Migration through the AKT Pathway
(2014-01-08)
Lu, Jeng-Wei
;
Liao, Chung-Yi
;
Yang, Wan-Yu
;
Lin, Yueh-Min
;
Jin, Shiow-Lian Catherine
Hepatocarcinogenesis commonly involves the gradual progression from hepatitis to fibrosis and cirrhosis, and ultimately to hepatocellular carcinoma (HCC). Endothelin 1 (Edn1) has been identified as a gene that is significantly up-regulated in HBx-induced HCC in mice. In this study, we further investigated the role of edn1 in hepatocarcinogenesis using a transgenic zebrafish model and a cell culture system. Liver-specific edn1 expression caused steatosis, fibrosis, glycogen accumulation, bile duct dilation, hyperplasia, and HCC in zebrafish. Overexpression of EDN1 in 293T cells enhanced cell proliferation and cell migration in in vitro and xenotransplantation assays and was accompanied with up-regulation of several cell cycle/proliferation- and migration-specific genes. Furthermore, expression of the unfolded protein response (UPR) pathway-related mediators, such as spliced XBP1, ATF6, IRE1, and PERK, was also up-regulated at both the RNA and protein levels. In the presence of an EDN1 inhibitor or an AKT inhibitor, these increases were diminished and the EDN1-induced migration ability also was disappeared, suggesting that the EDN1 effects act through activation of the AKT pathway to enhance the UPR and subsequently activate the expression of downstream genes. Additionally, p-AKT is enhanced in the edn1 transgenic fish compared to the GFP-mCherry control. The micro RNA miR-1 was found to inhibit the expression of EDN1. We also observed an inverse correlation between EDN1 and miR-1 expression in HCC patients. In conclusion, our data suggest that EDN1 plays an important role in HCC progression by activating the PI3K/AKT pathway and is regulated by miR-1.
Realization of Metal-Insulator Transition and Oxidation in Silver Nanowire Percolating Networks by Terahertz Reflection Spectroscopy
(2014-01-08)
Tsai, Yao-Jiun
;
Chang, Chi-Ying
;
Lai, Yi-Chun
;
Yu, Pei-Chen
;
Ahn, Hyeyoung
Metal nanowires (NWs) enable versatile applications in printed electronics and optoelectronics by serving as thin and flexible transparent electrodes. The performance of metal NWs as thin electrodes is highly correlated to the connectivity of NW meshes. The percolation threshold of metal NW films corresponds to the minimum density of NWs to form the transparent, yet conductive metal NW networks. Here, we determine the percolation threshold of silver NW (AgNW) networks by using morphological analysis and terahertz (THz) reflection spectroscopy. From the divergent behavior of carrier scattering time and the increase of carrier backscattering factor, the critical NW density at which crossover from Drude to non-Drude behavior of THz conductivity occurs can be unambiguously determined for AgNW thin films. Furthermore, the natural oxidation of AgNWs which causes the gradual reduction of the connectivity of the AgNW network is also realized by the THz spectroscopy. The selective oxidation of NW-to-NW junctions weakens the ohmic contact, and for AgNWs near a critical density, it can even lead to metal insulator transition. The presented results offer invaluable information to accelerate the deployment of metal nanowires for next-generation electronics and optoelectronics on flexible substrates.
Evaluation of the Antitumor Effects of BPR1J-340, a Potent and Selective FLT3 Inhibitor, Alone or in Combination with an HDAC Inhibitor, Vorinostat, in AML Cancer
(2014-01-08)
Lin, Wen-Hsing
;
Yeh, Teng-Kuang
;
Jiaang, Weir-Torn
;
Yen, Kuei-Jung
;
Chen, Chun-Hwa
Overexpression or/and activating mutation of FLT3 kinase play a major driving role in the pathogenesis of acute myeloid leukemia (AML). Hence, pharmacologic inhibitors of FLT3 are of therapeutic potential for AML treatment. In this study, BPR1J-340 was identified as a novel potent FLT3 inhibitor by biochemical kinase activity (IC50 approximately 25 nM) and cellular proliferation (GC(50) approximately 5 nM) assays. BPR1J-340 inhibited the phosphorylation of FLT3 and STAT5 and triggered apoptosis in FLT3-ITD+ AML cells. The pharmacokinetic parameters of BPR1J-340 in rats were determined. BPR1J-340 also demonstrated pronounced tumor growth inhibition and regression in FLT3-ITD+ AML murine xenograft models. The combination treatment of the HDAC inhibitor vorinostat (SAHA) with BPR1J-340 synergistically induced apoptosis via Mcl-1 down-regulation in MOLM-13 AML cells, indicating that the combination of selective FLT3 kinase inhibitors and HDAC inhibitors could exhibit clinical benefit in AML therapy. Our results suggest that BPR1J-340 may be further developed in the preclinical and clinical studies as therapeutics in AML treatments.
Ultrathin Oriented BiFeO3 Films from Deposition of Atomic Layers with Greatly Improved Leakage and Ferroelectric Properties
(2014-01-08)
Liu, Yen-Ting
;
Ku, Ching-Shun
;
Chiu, Shang-Jui
;
Lee, Hsin-Yi
;
Chen, San-Yuan
Highly (001)-oriented BiFeO3 ultrathin films of total thickness of less than 10 nm were deposited on Si(001) substrates via deposition of atomic layers (ALD) with a LaNiO3 buffer. A radio-frequency (RF)-sputtered sample of the same thickness was prepared for comparison. The ALD combined with interrupted flow and an exchange reaction between Bi and Fe precursors provides a superior method to grow ternary compounds. According to X-ray diffraction, upon deposition at a temperature of less than 550 degrees C, the only phase in the film was BiFeO3. Anomalous fine structure from synchrotron X-ray diffraction certified the valence bonding through the BiFeO3 (001) diffraction signal. The stoichiometric ratio of BiFeO3 obtained from X-ray photoelectron spectroscopy indicated that ALD has a proportion much improved over the RF preparation, and this is also in agreement with the results for diffraction anomalous fine structure. The use of high-resolution transmission electron and atomic force microscopes showed that the layer structure and morphology from ALD presented a satisfactory coverage, more conformal than that with the RF method. The BiFeO3 thin film deposited with ALD shows excellent leakage, improved at least 1000 times with respect to the RF preparation, making this method suitable for the fabrication of ferroelectric random-access memory devices. From the hysteresis loop, the largest remanent polarization was observed as 2P(r) = 2.0 mu C cm(-2).
Identification and Chronological Analysis of Genomic Signatures in Influenza A Viruses
(2014-01-08)
Hu, Yuh-Jyh
;
Tu, Po-Chin
;
Lin, Chun-Sheng
;
Guo, Szu-Ting
;
分子醫學與生物工程研究所
An increase in the availability of data on the influenza A viruses (IAV) has enabled the identification of the potential determinants of IAV host specificity using computational approaches. In this study, we proposed an alternative approach, based on the adjusted Rand index (ARI), for the evaluation of genomic signatures of IAVs and their ability to distinguish hosts they infected. Our experiments showed that the host-specific signatures identified using the ARI were more characteristic of their hosts than those identified using previous measures. Our results provided updates on the host-specific genomic signatures in the internal proteins of the IAV based on the sequence data as of February 2013 in the National Center for Biotechnology Information (NCBI). Unlike other approaches for signature recognition, our approach considered not only the ability of signatures to distinguish hosts (according to the ARI), but also the chronological relationships among proteins. We identified novel signatures that could be mapped to known functional domains, and introduced a chronological analysis to investigate the changes in host-specific genomic signatures over time. Our chronological analytical approach provided results on the adaptive variability of signatures, which correlated with previous studies' findings, and indicated prospective adaptation trends that warrant further investigation.
Porous Inorganic Materials from Living Porogens: Channel-like TiO2 from Yeast-Assisted Sol-Gel Process
(2014-01-08)
Chang, Yi-Chun
;
Lee, Chi-Young
;
Chiu, Hsin-Tien
;
應用化學系
;
Department of Applied Chemistry
Vitality of yeast cells maintained in an aqueous sol-gel solution containing titanium tetraisopropoxide and glucose. The living cells and their metabolites acted as the porogens for a channel-like TiO2 precursor. Further processing of the precursor offered a channel-like meso/macroporous TiO2, a potential anode material for Li-ion battery.
Image Alignment for Tomography Reconstruction from Synchrotron X-Ray Microscopic Images
(2014-01-09)
Cheng, Chang-Chieh
;
Chien, Chia-Chi
;
Chen, Hsiang-Hsin
;
Hwu, Yeukuang
;
Ching, Yu-Tai
A synchrotron X-ray microscope is a powerful imaging apparatus for taking high-resolution and high-contrast X-ray images of nanoscale objects. A sufficient number of X-ray projection images from different angles is required for constructing 3D volume images of an object. Because a synchrotron light source is immobile, a rotational object holder is required for tomography. At a resolution of 10 nm per pixel, the vibration of the holder caused by rotating the object cannot be disregarded if tomographic images are to be reconstructed accurately. This paper presents a computer method to compensate for the vibration of the rotational holder by aligning neighboring X-ray images. This alignment process involves two steps. The first step is to match the "projected feature points" in the sequence of images. The matched projected feature points in the x-theta plane should form a set of sine-shaped loci. The second step is to fit the loci to a set of sine waves to compute the parameters required for alignment. The experimental results show that the proposed method outperforms two previously proposed methods, Xradia and SPIDER. The developed software system can be downloaded from the URL, http://www.cs.nctu.edu.tw/similar to chengchc/SCTA or http://goo.gl/s4AMx.
Protective effects of Zhibai Dihuang Wan on renal tubular cells affected with gentamicin-induced apoptosis
(2014-01-10)
Hsu, Yung-Ho
;
Chen, Tso-Hsiao
;
Wu, Mei-Yi
;
Lin, Yuh-Feng
;
Chen, Wen-Liang
Ethnopharmacological relevance: Zhibai Dihuang Wan (ZDW) is an ancient traditional Chinese medicine composed of eight herbal ingredients and has been used to treat chronic kidney inflammation and diabetes for thousands of years. Nonetheless, the influence of ZDW on acute kidney injury is still unknown. We intended to identify the influence of ZDW on cell growth and gentamicin-induced apoptotic injury in renal tubular cells. Materials and methods: We extracted ZDW with artificial intestinal fluid and treated rat renal tubular cells (NRK-52E) with various concentrations of the ZDW extraction. Cell proliferation and gentamicin-induced apoptosis of NRK-52E cells were evaluated using real-time proliferation monitoring and annexin V staining, respectively. Western blotting was used to evaluate the levels of Bcl-2 and caspase-3 expression. The effect of ZDW on gentamicin-induced kidney injury was also monitored in mice using the terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL) assay, and the measurement of serum creatinine and blood urea nitrogen. Results: We found that 30 mu g/ml of ZDW promoted cell proliferation of the rat renal tubular cells. ZDW also expressed a dose-dependent protective effect against gentamicin-induced apoptosis in the cells. Pretreatment with 3 mu g/ml or 30 mu g/ml of ZDW maximally increased Bcl-2 and decreased cleaved caspase-3 in the gentamicin-treated NRK-52E cells. Among the herbal ingredients of ZDW, only Phellodendron amurense Rupr., bark (Cortex Phellodendri), and Anemarrhena asphodeloides Bunge, rhizome inhibited both the gentamicin-induced Bcl-2 decrease and cleaved caspase-3 increase. Phellodendron amurense Rupr., bark and Anemarrhena asphodeloides Bunge, rhizome also inhibited gentamicin-induced apoptosis at particular concentrations; however, these two ingredients were less effective than ZDW. In the mouse model of gentamicin-induced nephropathy, the ZDW treatment significantly reduced apoptotic cells in the renal cortex and improved renal function. Conclusions: Our results suggest that ZDW at adequate doses attenuates gentamicin-induced apoptotic injury in renal tubular cells and also protects kidneys from gentamicin-induced injury in mice. (C) 2013 Elsevier Ireland Ltd. All rights reserved.
More on the one-dimensional sliding-coin puzzle
(2014-01-10)
Lin, Ting-Yu
;
Tsai, Shi-Chun
;
Tsai, Wen-Nung
;
Tsay, Jong-Chuang
;
資訊工程學系
Consider a line of n nickels and n pennies with all nickels arranged to the left of all pennies, where n >= 3. The puzzle asks the player to rearrange the coins such that nickels and pennies alternate in the line. In each move, the player is allowed to slide k adjacent coins to hew positions without rotating. We first prove that for any integer k >= 2 it takes at least n moves to achieve the goal. A well-known optimal solution for the case k = 2 matches the lower bound. We also give optimal solutions for the case k = 3. (C) 2013 Elsevier B.V. All rights reserved.
多平面掃描洩漏波天線
(2014-01-11)
張榮原
;
陳富強
一種多平面掃描洩漏波天線，包括基板、第一天線串列、第二天線串列與多個控制單元。第一天線串列與第二天線串列相互交叉設置，以共用多個天線單元中的一預設天線單元。部分天線單元從預設天線單元的一第一與一第二傳輸線向外串接而形成第一天線串列，其餘的天線單元從預設天線單元的一第三與一第四傳輸線向外串接而形成第二天線串列。控制單元用以控制第一至第四傳輸線與這些天線單元之間的傳輸路徑，並致使洩漏波束切換至不同的掃描平面，且洩漏波束透過這些天線單元而隨著頻率的變化來進行掃描。
照明控制模組、包含其之攝影機及照明控制方法
(2014-01-11)
莊仁輝
;
羅國華
;
洪邦展
本發明提供一種照明控制模組、包含其之攝影機及照明控制方法。根據本發明之攝影機包含一感光模組、一發光模組以及一照明控制模組。該感光模組可接收來自該攝影機之一攝影方向上之一反射光線，並產生該攝影方向上之一影像。該發光模組向該攝影方向發射一光線。此外，該照明控制模組連接該發光模組，用以控制該發光模組所發射之該光線週期性地自一第一亮度變化至一第二亮度。
流體式光波導元件及其形成方法
(2014-01-11)
范士岡
;
簡家齊
;
盧羿彣
本發明提供一種流體式光波導元件及其形成方法，其是在包層流體中，藉由施加電場方式，驅動纖核流體於電極上。由於纖核流體是被電場所定義，所以各種二維形狀之纖核液體皆可藉由施加電壓所在的電極圖形上形成。本發明之流體式光波導元件擁有流體界面較平滑的優點，而且穩定的纖核與包層流體會消除流體流動時所產生的散射損失。
高速升壓之充電泵電路
(2014-01-11)
陳建廷
;
趙昌博
;
邵啟意
在此揭露一種充電泵電路(charge pump circuit)，其包含輸入訊號、二極體、第一控制開關、第二控制開關與充電元件。二極體用於控制輸入訊號的正向充電而防止該控制訊號的逆向漏電。當輸入訊號為第一電壓位準時，第一控制開關為關閉(close)，而當輸入訊號為第二電壓位準時，第一控制開關為開啟(open)。當輸入訊號為第一電壓位準時，第二控制開關為開啟(open)，而當輸入訊號為第二電壓位準時，第二控制開關為關閉(close)。每個充電元件電性連接該二極體，當輸入訊號為第一電壓位準時，電元件為充電狀態，而當輸入訊號為第二電壓位準時，充電元件為放電狀態。此充電泵電路可在一工作週期內完成升壓輸出電壓N倍的工作，大幅縮短升壓的時間。