Browsing by Issue Date, starting with "2014-08-15"

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Automated Segmentation and Quantification of White Matter Hyperintensities in Acute Ischemic Stroke Patients with Cerebral Infarction
(2014-08-15)
Tsai, Jang-Zern
;
Peng, Syu-Jyun
;
Chen, Yu-Wei
;
Wang, Kuo-Wei
;
Li, Chen-Hua
White matter hyperintensities (WMHs) of presumed vascular origin are common in ageing population, especially in patients with acute cerebral infarction and the volume has been reported to be associated with mental impairment and the risk of hemorrhage from antithrombotic agents. WMHs delineation can be computerized to minimize human bias. However, the presence of cerebral infarcts greatly degrades the accuracy of WMHs detection and thus limits the application of computerized delineation to patients with acute cerebral infarction. We propose a computer-assisted segmentation method to depict WMHs in the presence of cerebral infarcts in combined T1-weighted, fluid attenuation inversion recovery, and diffusion-weighted magnetic resonance imaging (MRI). The proposed method detects WMHs by empirical threshold and atlas information, with subtraction of white matter voxels affected by acute infarction. The method was derived using MRI from 25 hemispheres with WMHs only and 13 hemispheres with both WMHs and cerebral infarcts. Similarity index (SI) and correlation were utilized to assess the agreement between the new automated method and a gold standard visually guided semi-automated method done by an expert rater. The proposed WMHs segmentation approach produced average SI, sensitivity and specificity of 83.142 +/- 11.742, 84.154 +/- 16.086 and 99.988 +/- 0.029% with WMHs only and of 68.826 +/- 14.036, 74.381 +/- 18.473 and 99.956 +/- 0.054% with both WMHs and cerebral infarcts in the derivation cohort. The performance of the proposed method with an external validation cohort was also highly consistent with that of the experienced rater.
Urupocidin A: A New, Inducing iNOS Expression Bicyclic Guanidine Alkaloid from the Marine Sponge Monanchora pulchra
(2014-08-15)
Makarieva, Tatyana N.
;
Ogurtsova, Ekaterina K.
;
Denisenko, Vladimir A.
;
Dmitrenok, Pavel S.
;
Tabakmakher, Ksenya M.
Urupocidins A and B (1 and 2), bisguanidine alkaloids with an unprecedented skeleton system, derived from polyketide precursors and containing an unusual N-alkyl-N-hydroxyguanidine moiety, have been isolated from the sponge Monanhora pulchra. The structures of 1 and 2, including absolute configuration, were established using the detailed analysis of 1D and 2D NMR, CD, and mass spectra as well as chemical transformations. Compound 1 increases nitric oxide production in murine macrophages via inducing iNOS expression.
Contribution of thermal energy to initial ion production in matrix-assisted laser desorption/ionization observed with 2,4,6-trihydroxyacetophenone
(2014-08-15)
Lai, Yin-Hung
;
Chen, Bo-Gaun
;
Lee, Yuan Tseh
;
Wang, Yi-Sheng
;
Lin, Sheng Hsien
RATIONALE: Although several reaction models have been proposed in the literature to explain matrix-assisted laser desorption/ionization (MALDI), further study is still necessary to explore the important ionization pathways that occur under the high-temperature environment of MALDI. 2,4,6-Trihydroxyacetophenone (THAP) is an ideal compound for evaluating the contribution of thermal energy to an initial reaction with minimum side reactions. METHODS: Desorbed neutral THAP and ions were measured using a crossed-molecular beam machine and commercial MALDI-TOF instrument, respectively. A quantitative model incorporating an Arrhenius-type desorption rate derived from transition state theory was proposed. Reaction enthalpy was calculated using GAUSSIAN 03 software with dielectric effect. Additional evidence of thermal-induced proton disproportionation was given by the indirect ionization of THAP embedded in excess fullerene molecules excited by a 450 nm laser. RESULTS: The quantitative model predicted that proton disproportionation of THAP would be achieved by thermal energy converted from a commonly used single UV laser photon. The dielectric effect reduced the reaction Gibbs free energy considerably even when the dielectric constant was reduced under high-temperature MALDI conditions. With minimum fitting parameters, observations of pure THAP and THAP mixed with fullerene both agreed with predictions. CONCLUSIONS: Proton disproportionation of solid THAP was energetically favorable with a single UV laser photon. The quantitative model revealed an important initial ionization pathway induced by the abrupt heating of matrix crystals. In the matrix crystals, the dielectric effect reduced reaction Gibbs free energy under typical MALDI conditions. The result suggested that thermal energy plays an important role in the initial ionization reaction of THAP. Copyright (C) 2014 John Wiley & Sons, Ltd.
Rolling up Ge microtube from bare-Ge substrate
(2014-08-15)
Chen, C. H.
;
Niu, H.
;
Huang, R. T.
;
Lee, C. P.
;
奈米科技中心
We show Ge microtubes can be rolled-up from bare-Ge wafer at almost any position, once these films are released from its substrate. (C) 2014 Elsevier B.V. All rights reserved.
Enhanced charge transfer character of photoexcited states of dye sensitizer on the N719/TiO2 interface as revealed by electroabsorption spectra
(2014-08-15)
Awasthi, Kamlesh
;
Hsu, Hung-Yu
;
Diau, Eric Wei-Guang
;
Ohta, Nobuhiro
;
應用化學系
Electroabsorption (E-A) spectra of (Bu4N)(2)[Ru(dcbpyH)(2)(NCS)(2)] (N719) sensitized on TiO2 nanoparticles are very different from those of the N719 solid film. In contrast with N719 fixed in a solid form, N719 adsorbed on TiO2 shows a significant electric field effect on absorbance, indicating the strong interaction in the surface between N719 and TiO2. The magnitude of the change in electric dipole moment following absorption of N719 sensitized on TiO2 is much greater than that of the sold film, suggesting that the interfacial charge transfer occurs following photoexcitation of N719 adsorbed on TiO2 surface. (C) 2014 Elsevier B.V. All rights reserved.
Local structure and magnetic properties of ferromagnetic GaMnAs made by helium ion induced epitaxial crystallization annealing
(2014-08-15)
Chen, C. H.
;
Niu, H.
;
Yan, D. C.
;
Hsieh, H. H.
;
Huang, R. T.
In this study we show GaMnAs preparation by Mn implantation in GaAs followed by helium ion beam induced epitaxial crystallization annealing. The characteristics of the Mn-implanted layer were investigated by X-ray diffraction, and transmission electron microscopy. The magnetic nature of the Mn-implanted layer was investigated with a superconducting quantum interference device. Structure analysis showed that Mn ions were incorporated substitutionally into the GaAs lattice without the formation of any detectable secondary phases. The remanent magnetic moment exhibited room temperature ferromagnetism. Additional measurement using X-ray magnetic circular dichroism also revealed that the carriers were spin polarized. (C) 2014 Elsevier B.V. All rights reserved.
400-Gb/s Transmission Over 10-km SSMF Using Discrete Multitone and 1.3-mu m EMLs
(2014-08-15)
Chan, Trevor
;
Lu, I-Cheng
;
Chen, Jyehong
;
Way, Winston I.
;
光電工程學系
We experimentally demonstrated 400-Gb/s transmission over 10-km standard single-mode using discrete multi-tone (DMT) and four 1.3-mu m local-area-network wavelength-division-multiplexed externally modulated lasers. A reasonably good system margin has been obtained. We have also investigated the fundamental limitations of using semiconductor optical amplifiers for DMT-based systems.
Contribution of thermal energy to initial ion production in matrix-assisted laser desorption/ionization observed with 2,4,6-trihydroxyacetophenone
(2014-08-15)
Lai, Yin-Hung
;
Chen, Bo-Gaun
;
Lee, Yuan Tseh
;
Wang, Yi-Sheng
;
Lin, Sheng Hsien
RATIONALE: Although several reaction models have been proposed in the literature to explain matrix-assisted laser desorption/ionization (MALDI), further study is still necessary to explore the important ionization pathways that occur under the high-temperature environment of MALDI. 2,4,6-Trihydroxyacetophenone (THAP) is an ideal compound for evaluating the contribution of thermal energy to an initial reaction with minimum side reactions. METHODS: Desorbed neutral THAP and ions were measured using a crossed-molecular beam machine and commercial MALDI-TOF instrument, respectively. A quantitative model incorporating an Arrhenius-type desorption rate derived from transition state theory was proposed. Reaction enthalpy was calculated using GAUSSIAN 03 software with dielectric effect. Additional evidence of thermal-induced proton disproportionation was given by the indirect ionization of THAP embedded in excess fullerene molecules excited by a 450 nm laser. RESULTS: The quantitative model predicted that proton disproportionation of THAP would be achieved by thermal energy converted from a commonly used single UV laser photon. The dielectric effect reduced the reaction Gibbs free energy considerably even when the dielectric constant was reduced under high-temperature MALDI conditions. With minimum fitting parameters, observations of pure THAP and THAP mixed with fullerene both agreed with predictions. CONCLUSIONS: Proton disproportionation of solid THAP was energetically favorable with a single UV laser photon. The quantitative model revealed an important initial ionization pathway induced by the abrupt heating of matrix crystals. In the matrix crystals, the dielectric effect reduced reaction Gibbs free energy under typical MALDI conditions. The result suggested that thermal energy plays an important role in the initial ionization reaction of THAP. Copyright (C) 2014 John Wiley & Sons, Ltd.
Rolling up Ge microtube from bare-Ge substrate
(2014-08-15)
Chen, C. H.
;
Niu, H.
;
Huang, R. T.
;
Lee, C. P.
;
奈米科技中心
We show Ge microtubes can be rolled-up from bare-Ge wafer at almost any position, once these films are released from its substrate. (C) 2014 Elsevier B.V. All rights reserved.
Local structure and magnetic properties of ferromagnetic GaMnAs made by helium ion induced epitaxial crystallization annealing
(2014-08-15)
Chen, C. H.
;
Niu, H.
;
Yan, D. C.
;
Hsieh, H. H.
;
Huang, R. T.
In this study we show GaMnAs preparation by Mn implantation in GaAs followed by helium ion beam induced epitaxial crystallization annealing. The characteristics of the Mn-implanted layer were investigated by X-ray diffraction, and transmission electron microscopy. The magnetic nature of the Mn-implanted layer was investigated with a superconducting quantum interference device. Structure analysis showed that Mn ions were incorporated substitutionally into the GaAs lattice without the formation of any detectable secondary phases. The remanent magnetic moment exhibited room temperature ferromagnetism. Additional measurement using X-ray magnetic circular dichroism also revealed that the carriers were spin polarized. (C) 2014 Elsevier B.V. All rights reserved.
Pressure-induced structural phase transition in bulk Zn0.98Mn0.02O by angular dispersive X-ray diffraction
(2014-08-15)
Lin, Chih-Ming
;
Lin, Kung-Liang
;
Chern, Yu-Ker
;
Hsu, Chia-Hung
;
Sheu, Hwo-Shuenn
The high pressure induced phase transition in bulk Zn0.98Mn0.02O at ambient temperature have been investigated using angular-dispersive X-ray diffraction (ADXRD) under high pressure up to around 13.80 GPa. For loading run, in situ ADXRD measurements found that a wurtzite-to-rocksalt structural phase transition pressure of bulk Zn0.98Mn0.02O began at 7.35 GPa. The fitting of volume compression data to the third-order Birch-Murnaghan equation of state yielded that the zero-pressure isothermal bulk moduli and the first-pressure derivatives were 157(8) GPa and 8(3) for the B4 phase, respectively. When decompress bulk Zn0.98Mn0.02O to ambient pressure a large part of the bulk Zn0.98Mn0.02O reverted to the B4 phase and only a small amount of the metastable B1 phase remained. We have exhibits the pressure dependence of lattice constant a and c axis, and the normalized ratio c/a of the bulk Zn0.98Mn0.02O. Possible pressure-induced phase transition mechanisms were explored by examining the cell parameters and the internal structural parameter (u) with pressures. The effect of the 3d electrons of manganese to increase the nearest-neighbor distance of O to Zn (Mn) parallel to the c axis may be the main reason for the phase transition of bulk Zn0.98Mn0.02O. An increase in the u value with pressure indicates that the B4-to-B1 phase transformation in bulk Zn0.98Mn0.02O is likely via the hexagonal path. (C) 2014 Elsevier B.V. All rights reserved.
Diversified portfolios with different entropy measures
(2014-08-15)
Yu, Jing-Rung
;
Lee, Wen-Yi
;
Chiou, Wan-Jiun Paul
;
科技管理研究所
;
Institute of Management of Technology
One of the major issues for Markowitz mean-variance model is the errors in estimations cause "corner solutions" and low diversity in the portfolio. In this paper, we compare the mean-variance efficiency, realized portfolio values, and diversity of the models incorporating different entropy measures by applying multiple criteria method. Differing from previous studies, we evaluate twenty-three portfolio over-time rebalancing strategies with considering short-sales and various transaction costs in asset diversification. Using the data of the most liquid stocks in Taiwan\'s market, our finding shows that the models with Yager\'s entropy yield higher performance because they respond to the change in market by reallocating assets more effectively than those with Shannon\'s entropy and with the minimax disparity model. Furthermore, including entropy in models enhances diversity of the portfolios and makes asset allocation more feasible than the models without incorporating entropy. (C) 2014 Elsevier Inc. All rights reserved.
Urupocidin A: A New, Inducing iNOS Expression Bicyclic Guanidine Alkaloid from the Marine Sponge Monanchora pulchra
(2014-08-15)
Makarieva, Tatyana N.
;
Ogurtsova, Ekaterina K.
;
Denisenko, Vladimir A.
;
Dmitrenok, Pavel S.
;
Tabakmakher, Ksenya M.
Urupocidins A and B (1 and 2), bisguanidine alkaloids with an unprecedented skeleton system, derived from polyketide precursors and containing an unusual N-alkyl-N-hydroxyguanidine moiety, have been isolated from the sponge Monanhora pulchra. The structures of 1 and 2, including absolute configuration, were established using the detailed analysis of 1D and 2D NMR, CD, and mass spectra as well as chemical transformations. Compound 1 increases nitric oxide production in murine macrophages via inducing iNOS expression.
電性連接結構及其製備方法
(2014-08-16)
陳智
;
劉道奇
;
黃以撒
;
劉健民
本發明係有關於一種用以電性連接一第一基板及一第二基板之電性連接結構及其製備方法,其中製備方法包括:(A)提供一第一基板及一第二基板,其中第一基板上係設有一第一銅膜,第二基板上係設有一第一金屬膜,第一銅膜之一第一接合面係為一含(111)面之接合面,且該第一金屬膜具有一第二接合面;以及(B)將第一銅膜及第一金屬膜相互接合以形成接點,其中第一銅膜之第一接合面係與第一金屬膜之第二接合面相互對應。
石墨氧化物製備方法
(2014-08-16)
韋光華
;
鄧文成
一種石墨氧化物之製備方法，包含提供一電漿電解裝置，其中電漿電解裝置具有一電解液，以及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石墨電極，使石墨電極進行一電漿電解反應以得到石墨氧化物。本發明藉由電漿電解程序，可在相對低溫、一般壓力及非常短的時間內，且不需濃縮酸及強氧化劑的條件下，即可製備石墨氧化物。本發明利用電漿電解程序將石墨直接製備為石墨氧化物，而不需任何事先純化。本發明之電漿電解程序相當具潛力，具有低成本、易製備、高效率及環保之優勢。
螢光增強裝置
(2014-08-16)
徐樹剛
;
張淑閔
一種螢光增強裝置包含光源、螢光材料層、第一光子晶體層及第二光子晶體層。光源可發射激發光，激發螢光材料層中的螢光材料進而發射螢光。第一光子晶體層與第二光子晶體層係設置於螢光材料層之激發光入射方向之下游。第一光子晶體層之第一光子晶體之光能隙與激發光之波長重疊，藉以反射激發光至螢光材料層。第二光子晶體層之第二光子晶體光能隙與螢光材料之螢光波長重疊，藉以反射螢光材料所發射之螢光。本發明之優勢包括可重複使用光子晶體進行感測並可增強螢光強度。
液晶聚合物透鏡結構
(2014-08-16)
陳宏山
;
林怡欣
本發明係揭露一種液晶聚合物透鏡結構，其包含折射率分佈膜、透鏡以及可撓性基材。可撓性基材係貼附於透鏡之表面，折射率分佈膜則封裝於可撓性基材中，且具有不均勻的折射率分佈。本發明之折射率分佈膜可設計成使液晶聚合物透鏡結構擁有多段式或漸進式的屈光力變化，以幫助老花眼於近距離之閱讀。
多重亮度影像處理方法
(2014-08-16)
莊仁輝
;
鄧文治
;
劉晉瑋
本發明係揭露一種多重亮度影像處理方法,其係利用一處理器執行之。首先,接收具有多重週期亮度之序列影像,並依其影像週期分成複數影像群組。接著,合併每一影像群組中的每一影像,以產生複數合併影像,並據此得到一影像序列。或者,建立複數序列,並將每一影像群組中具有同一亮度之影像按順序排列在同一序列中。然後,對每一序列之每一影像重新依序編號,以得到複數影像序列。當影像序列取得後,便可壓縮影像序列為一影像檔。本發明能改善多重亮度序列影像壓縮比,以減小影像檔案大小,並節省硬碟儲存空間。
編碼串流產生裝置、韻律訊息編碼裝置、韻律結構分析裝置與語音合成之裝置及方法
(2014-08-16)
陳信宏
;
王逸如
;
江振宇
;
謝喬華
本案係提供一種語音合成之裝置，其包括一階層式韻律模組，提供一階層式韻律模型；一韻律結構分析單元，接收一低階語言參數、一高階語言參數及一第一韻律參數，且根據該高階語言參數、該低階語言參數、該第一韻律參數及該階層式韻律模組，產生至少一韻律標記；以及一韻律參數合成單元，根據該階層式韻律模組、該低階語言參數及該韻律標記來合成一第二韻律參數。
人體通道傳輸方法以及系統
(2014-08-16)
桑梓賢
;
周世傑
;
張添烜
;
孫致晴
;
許碩文
一種人體通道傳輸方法包含以下步驟:使一第一人體通道傳輸裝置透過數種人體通道傳輸方式,分別傳送一測試訊號。藉由一第二人體通道傳輸裝置透過人體通道傳輸方式,分別接收測試訊號。根據透過各人體通道傳輸方式所接收之測試訊號,計算各人體通道傳輸方式之一訊噪比。選擇人體通道傳輸方式中,其訊噪比最大者。使第一人體通道傳輸裝置以及第二人體通道傳輸裝置間,以所選擇之人體通道傳輸方式傳輸資料。