Browsing by Issue Date, starting with "2013-02-20"

Now showing 1 - 20 of 32468

Fouling mitigation of a dead-end microfiltration by mixing-enhanced preoxidation for Fe and Mn removal from groundwater
(2013-02-20)
Lin, Jr-Lin
;
Huang, Chihpin
;
Ruhsing, Pan Jill
;
Wang, Yau-Shian
;
環境工程研究所
A combination of oxidation and microfiltration (oxidation-MF) is commonly used to remove Fe and Mn from groundwater. The characteristics of Fe and Mn oxides formed by oxidation can be significantly affected by the mixing intensity during oxidation, which subsequently influences the performance of membrane filtration. To optimize oxidation-MF, the critical role of mixing intensity on Fe and Mn oxide formation was investigated. Sufficient oxidant (NaOCl) was added to a prepared ferrous solution with or without Mn ions to oxidize the ions at different mixing intensities, followed by a dead-end MF for 30 min at a constant transmembrane pressure of 1 kg/cm(2). A custom-made module surrounded by a tube membrane was used in microfiltration. The resistance of membrane filtration was calculated by a resistance-in-series model. Cake resistance (R-c) dominated the fouling of the membrane, which depended on the composition of oxides. Oxides formed at high mixing intensity were smaller and more compact, which resulted in reduced R-c, and increased permeate flux. The presence of oxidized Mn aggravated membrane fouling. Permeate flux declined rapidly as a result of the cake formed by Fe-Mn oxides with increased hydrophobicity. The irreversible fouling of the dead-end MF was insensitive to mixing intensity during prechlorination, while the irreversible fouling induced by Fe-Mn oxides was more severe than that by Fe oxides as membrane filtration cycle progressed. The results show that membrane flux of a dead-MF can be effectively improved by prechlorination with enhanced mixing due to the formation of a permeable cake layer with low cake compressibility in the membrane filtration. (c) 2012 Elsevier B.V. All rights reserved.
Effect of nanoholes on the vortex core fermion spectrum and heat transport in p-wave superconductors
(2013-02-20)
Rosenstein, B.
;
Shapiro, I.
;
Shapiro, B. Ya
;
電子物理學系
;
Department of Electrophysics
The spectrum of core excitations of the Abrikosov vortex pinned by a nanohole of the size of the coherence length is considered. While the neutral zero energy Majorana core state remains intact due to its topological origin, the energy of charged excitations is significantly enhanced compared to that in the unpinned vortex. As a consequence of the pinning the minigap separating the Majorana state from the charged levels increases from Delta(2)/E-F (E-F is the Fermi energy and Delta is the bulk p-wave superconducting gap) to a significant fraction of Delta. Suppression of the thermodynamic and kinetic effects of the charged excitations allows us to isolate the Majorana state so it can be used for quantum computation. It is proposed that thermal conductivity along the vortex cores is a sensitive method to demonstrate the minigap. Using the Butticker-Landauer-Kopnin formula, we calculate the thermal conductance beyond the linear response as a function of the hole radius.
Computational Analysis of KRAS Mutations: Implications for Different Effects on the KRAS p.G12D and p.G13D Mutations
(2013-02-20)
Chen, Chih-Chieh
;
Er, Tze-Kiong
;
Liu, Yen-Yi
;
Hwang, Jenn-Kang
;
Jesus Barrio, Maria
Background: The issue of whether patients diagnosed with metastatic colorectal cancer who harbor KRAS codon 13 mutations could benefit from the addition of anti-epidermal growth factor receptor therapy remains under debate. The aim of the current study was to perform computational analysis to investigate the structural implications of the underlying mutations caused by c.38G>A (p.G13D) on protein conformation. Methods: Molecular dynamics (MD) simulations were performed to understand the plausible structural and dynamical implications caused by c.35G>A (p.G12D) and c.38G>A (p.G13D). The potential of mean force (PMF) simulations were carried out to determine the free energy profiles of the binding processes of GTP interacting with wild-type (WT) KRAS and its mutants (MT). Results: Using MD simulations, we observed that the root mean square deviation (RMSD) increased as a function of time for the MT c.35G>A (p.G12D) and MT c.38G>A (p.G13D) when compared with the WT. We also observed that the GTP-binding pocket in the c.35G>A (p.G12D) mutant is more open than that of the WT and the c.38G>A (p.G13D) proteins. Intriguingly, the analysis of atomic fluctuations and free energy profiles revealed that the mutation of c.35G>A (p.G12D) may induce additional fluctuations in the sensitive sites (P-loop, switch I and II regions). Such fluctuations may promote instability in these protein regions and hamper GTP binding. Conclusions: Taken together with the results obtained from MD and PMF simulations, the present findings implicate fluctuations at the sensitive sites (P-loop, switch I and II regions). Our findings revealed that KRAS mutations in codon 13 have similar behavior as KRAS WT. To gain a better insight into why patients with metastatic colorectal cancer (mCRC) and the KRAS c.38G>A (p.G13D) mutation appear to benefit from anti-EGFR therapy, the role of the KRAS c.38G>A (p.G13D) mutation in mCRC needs to be further investigated.
Parallel Screening of Wild-Type and Drug-Resistant Targets for Anti-Resistance Neuraminidase Inhibitors
(2013-02-20)
Hsu, Kai-Cheng
;
Hung, Hui-Chen
;
Horng, Jim-Tong
;
Fang, Ming-Yu
;
Chang, Chun-Yu
Infection with influenza virus is a major public health problem, causing serious illness and death each year. Emergence of drug-resistant influenza virus strains limits the effectiveness of drug treatment. Importantly, a dual H275Y/I223R mutation detected in the pandemic influenza A 2009 virus strain results in multidrug resistance to current neuraminidase (NA) drugs. Therefore, discovery of new agents for treating multiple drug-resistant (MDR) influenza virus infections is important. Here, we propose a parallel screening strategy that simultaneously screens wild-type (WT) and MDR NAs, and identifies inhibitors matching the subsite characteristics of both NA-binding sites. These may maintain their potency when drug-resistant mutations arise. Initially, we analyzed the subsite of the dual H275Y/I223R NA mutant. Analysis of the site-moiety maps of NA protein structures show that the mutant subsite has a relatively small volume and is highly polar compared with the WT subsite. Moreover, the mutant subsite has a high preference for forming hydrogen-bonding interactions with polar moieties. These changes may drive multidrug resistance. Using this strategy, we identified a new inhibitor, Remazol Brilliant Blue R (RB19, an anthraquinone dye), which inhibited WT NA and MDR NA with IC50 values of 3.4 and 4.5 mu M, respectively. RB19 comprises a rigid core scaffold and a flexible chain with a large polar moiety. The former interacts with highly conserved residues, decreasing the probability of resistance. The latter forms van der Waals contacts with the WT subsite and yields hydrogen bonds with the mutant subsite by switching the orientation of its flexible side chain. Both scaffolds of RB19 are good starting points for lead optimization. The results reveal a parallel screening strategy for identifying resistance mechanisms and discovering anti-resistance neuraminidase inhibitors. We believe that this strategy may be applied to other diseases with high mutation rates, such as cancer and human immunodeficiency virus type 1.
Microstructure and magnetic properties of oxidized titanium nitride thin films in situ grown by pulsed laser deposition
(2013-02-20)
Chen, S. C.
;
Sung, K. Y.
;
Tzeng, W. Y.
;
Wu, K. H.
;
Juang, J. Y.
Different oxidation states of titanium nitride thin films, including pure TiN(h 0 0), TiN1-xOx(h 0 0), Ti2O3(0 0 l) and pure anatase TiO2(0 0 l), were prepared by pulsed laser deposition with various oxygen pressures (P-O2) using a TiN target. Elaborative evolutions of the crystal and electronic structures of the obtained films were examined systematically by x-ray diffraction and x-ray absorption spectroscopy. We found that the Ti2O3(0 0 l) film, which was prepared at oxygen pressures P-O2 = 10(-4) Torr, exhibited the maximum room temperature ferromagnetism (RTFM) behaviour. The bound magnetic polaron model is used to clarify the origin of RTFM in these films.
Coherent pi-electron dynamics of (P)-2,2 '-biphenol induced by ultrashort linearly polarized UV pulses: Angular momentum and ring current
(2013-02-21)
Mineo, H.
;
Lin, S. H.
;
Fujimura, Y.
;
應用化學系分子科學碩博班
;
Institute of Molecular science
The results of a theoretical investigation of coherent pi-electron dynamics for nonplanar (P)-2,2'-biphenol induced by ultrashort linearly polarized UV pulses are presented. Expressions for the time-dependent coherent angular momentum and ring current are derived by using the density matrix method. The time dependence of these coherences is determined by the off-diagonal density matrix element, which can be obtained by solving the coupled equations of motion of the electronic-state density matrix. Dephasing effects on coherent angular momentum and ring current are taken into account within the Markov approximation. The magnitudes of the electronic angular momentum and current are expressed as the sum of expectation values of the corresponding operators in the two phenol rings (L and R rings). Here, L (R) denotes the phenol ring in the left (right)-hand side of (P)-2,2'-biphenol. We define the bond current between the nearest neighbor carbon atoms C-i and C-j as an electric current through a half plane perpendicular to the C-i-C-j bond. The bond current can be expressed in terms of the inter-atomic bond current. The inter-atomic bond current (bond current) depends on the position of the half plane on the bond and has the maximum value at the center. The coherent ring current in each ring is defined by averaging over the bond currents. Since (P)-2,2'-biphenol is nonplanar, the resultant angular momentum is not one-dimensional. Simulations of the time-dependent coherent angular momentum and ring current of (P)-2,2'-biphenol excited by ultrashort linearly polarized UV pulses are carried out using the molecular parameters obtained by the time-dependent density functional theory (TD-DFT) method. Oscillatory behaviors in the time-dependent angular momentum (ring current), which can be called angular momentum (ring current) quantum beats, are classified by the symmetry of the coherent state, symmetric or antisymmetric. The bond current of the bridge bond linking the L and R rings is zero for the symmetric coherent state, while it is nonzero for the antisymmetric coherent state. The magnitudes of ring current and ring current-induced magnetic field are also evaluated, and their possibility as a control parameter in ultrafast switching devices is discussed. The present results give a detailed description of the theoretical treatment reported in our previous paper [H. Mineo, M. Yamaki, Y. Teranish, M. Hayashi, S. H. Lin, and Y. Fujimura, J. Am. Chem. Soc. 134, 14279 (2012)]. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4790595]
可注射性智慧凝膠及其製備方法
(2013-02-21)
劉典謨
;
蕭孟軒
;
林立傑
一種可注射性智慧凝膠及其製備方法，係對於改質後之幾丁聚醣，加入鹼性結構安定劑及稀釋溶液，而將幾丁聚醣溶液調整為偏中性，以接近人體之pH值，並可在低溫下形成可流動狀態的幾丁聚醣溶膠，當回到人體溫度則形成不可流動之幾丁聚醣凝膠，或者，利用於幾丁聚醣溶液中加入高分子電解液後再添加鈣離子或調成酸性溶液的方式，亦可將可流動狀態的幾丁聚醣溶膠轉為不可流動的幾丁聚醣凝膠，藉此製備而成的可注射性智慧凝膠不但具有可注射性，同時，可作為已載有藥物分子的磁敏性奈米膠囊之藥物載體凝膠，經由外加的磁場、電場及超音波等非接觸力的方式，控制其膠囊的破裂而釋放藥物至可注射性智慧凝膠中，再進行長時效及可階段性的藥物釋放，在生醫工程方面極具利用價值。
高分子基板之高頻覆晶封裝製程及其結構
(2013-02-21)
張翼
;
許立翰
;
胡志偉
;
吳偉誠
;
王景德
本發明係提供一種高分子基板之高頻覆晶封裝製程及其結構，其係利用一階層之高頻覆晶封裝製程所封裝之結構，該結構可有效解決習用經由二階層之高頻覆晶封裝製程所製造之結構，其不僅在高頻特性上會帶來一額外之入射損耗與反射損耗，同時在應用上容易產生一可靠度問題、以及在該習用結構中之一陶瓷基板的製程良率上，仍存在有不佳及成本偏高等缺點。
Infrared identification of the sigma-complex of Cl-C6H6 in the reaction of chlorine atom and benzene in solid para-hydrogen
(2013-02-21)
Bahou, Mohammed
;
Witek, Henryk
;
Lee, Yuan-Pern
;
應用化學系
;
應用化學系分子科學碩博班
The reaction of a chlorine atom with benzene (C6H6) is important in organic chemistry, especially in site-selective chlorination reactions, but its product has been a subject of debate for five decades. Previous experimental and theoretical studies provide no concrete conclusion on whether the product is a pi- or sigma-form of the Cl-C6H6 complex. We took advantage of the diminished cage effect of para-hydrogen (p-H-2) to produce Cl in situ to react with C6H6 (or C6D6) upon photolysis of a Cl-2/C6H6 (or C6D6)/p-H-2 matrix at 3.2 K. The infrared spectrum, showing intense lines at 1430.5, 833.6, 719.8, 617.0, and 577.4 cm(-1), and several weaker ones for Cl-C6H6, and the deuterium shifts of observed new lines unambiguously indicate that the product is a 6-chlorocyclohexadienyl radical, i.e., the sigma-complex of Cl-C6H6. Observation of the s-complex rather than the pi-complex indicates that the s-complex is more stable in solid p-H-2 at 3.2 K. The spectral information is crucial for further investigations of the Cl + C6H6 reaction either in the gaseous or solution phase. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4790860]
應用於大眾運輸系統中的網路連結建立方法
(2013-02-21)
曾建超
;
李勇昇
;
張又仁
;
陳世揚
揭露一種應用於大眾運輸系統中的網路連結建立實施方法範例。預先建立一主代理器與一大眾運輸載具間之一第一通道。預先建立該主代理器與一拜訪代理器間之一第二通道。在該主代理器的協助下，該拜訪代理器預先授權給該大眾運輸載具，並分配該大眾運輸載具可用的一網路資源。在該主代理器的協助下，該大眾運輸載具預先得知該拜訪代理器所配置的該網路資源，而且，該大眾運輸載具預先完成對該拜訪代理器的一連結設定。當該大眾運輸載具移入一拜訪網路時，依預先完成的該連結設定，該大眾運輸載具與該拜訪代理器間建立網路連線。
Quantum Confined Stark Effect in Au-8 and Au-25 Nanoclusters
(2013-02-21)
Wen, Xiaoming
;
Yu, Pyng
;
Toh, Yon-Rui
;
Tang, Jau
;
光電工程學系
The quantum confined Stark effect is investigated for the first time in bovine serum albumin (BSA) protected Au-8 and Au-25 nanoclusters. We observed a red-shift of 63 meV in Au-8 nanoclusters upon an increase in pH from 2.14 to 12.0. Such behavior could be well explained in terms of the presence of a linear polar component and a quadratic polarizable component. In contrast, Au-25 nanoclusters exhibit more complicated Stark shifts due to their specific core/semiring structure. A plateau of the Stark shift was observed in both absorption and fluorescence, showing an offset of 30 meV. The lifetime measurements confirm that the plateau is due to the screening effect of the semirings in Au-25@BSA. Moreover, the dual fluorescent bands of Au-25 nanoclusters exhibit two different Stark shifts of 79 and 52 meV, respectively. The experimental data indicate that the Stark shift in both Au-8@BSA and Au-25@BSA has a significant linear polar component due to their asymmetric structure. This study suggests that gold nanoclusters can become a potentially useful candidate in probing local electric fields and also in pH-sensing in nanoscale environment of biological systems.
基於鄰近覺察之同時傳輸的媒介存取控制協定裝置與方法
(2013-02-21)
王蒞君
;
王中瑋
一種基於鄰近覺察之同時傳輸的媒介存取控制協定裝置與方法，係確認在一無線網路下是否多條通訊連線可以同時被建立，其中一鄰居探索模組使得此無線網路上的每一節點能夠取得它的多步鄰居之範圍內的拓樸資訊，一跨階層觀察模組整合實體與虛擬載波感測並觀察此無線網路下的一媒介存取控制層裡的一控制框的位址欄位，並且比較此控制框之位址欄位裡的資訊與藉由此鄰居探索模組取得的拓樸資訊，來確認此多條通訊連線是否可以被建立以達到同時傳輸。
The Thermostable Direct Hemolysin from Grimontia hollisae Causes Acute Hepatotoxicity In Vitro and In Vivo
(2013-02-21)
Lin, Yan-Ren
;
Chen, Yao-Li
;
Wang, Keh-Bin
;
Wu, Yi-Fang
;
Wang, Yu-Kuo
Background: G. hollisae thermostable direct hemolysin (Gh-TDH) is produced by most strains of G. hollisae. This toxin has been reported to be absorbed in the intestines in humans. Secondary liver injury might be caused by venous return of the toxin through the portal system. We aimed to firstly analyze the in vitro and in vivo hepatotoxicity of Gh-TDH. Methods: Liver cells (primary human non-cancer cell and FL83B mouse cells) were treated and mice (BALB/c) were fed with this toxin to investigate its hepatotoxicity. Morphological examination and cytotoxicity assays using liver cells were also performed. Fluorescein isothiocyanate-conjugated toxin was used to analyze the localization of this protein in liver cells. Mice were subjected to liver function measurements and liver biopsies following toxin treatment and wild-type bacterial infection. PET (positron emission tomography)/CT (computed tomography) images were taken to assess liver metabolism during acute injury and recovery. Results: The effect of hepatotoxicity was dose and time dependent. Cellular localization showed that the toxin was initially located around the cellular margins and subsequently entered the nucleus. Liver function measurements and liver biopsies of the mice following treatment with toxin or infection with wild-type Grimontia hollisae showed elevated levels of transaminases and damage to the periportal area, respectively. The PET/CT images revealed that the reconstruction of the liver continued for at least one week after exposure to a single dose of the toxin or bacterial infection. Conclusions: The hepatotoxicity of Gh-TDH was firstly demonstrated. The damage was located in the periportal area of the liver, and the liver became functionally insufficient.
構築多元文化的溫馨橋樑
(2013-02-24)
鄭乃文
;
Department of Communication and Technology
;
傳播與科技學系
身為新住民的好朋友與老師，林麗文用愛心與耐心建立橋樑，希望能填補新住民與台灣人間的隔閡，同時使新住民的生活水準提昇。
室內設計　把關自己來
(2013-02-24)
龔霈鏵
;
Department of Communication and Technology
;
傳播與科技學系
一般民眾對於室內設計的流程和相關證照及法規不了解，造成了社會上許多非合格的設計師不當得利，卻苦無辦法解決。學習一些簡單的辨識方法，讓自己和他人不會再上當受騙。
已經過去的　最好的時光
(2013-02-24)
歐士豪
;
Department of Communication and Technology
;
傳播與科技學系
最好的時光是導演侯孝賢於2005年拍攝的電影，由「戀愛夢」、「自由夢」、「青春夢」三段故事組成。
停不下來的紅舞鞋
(2013-02-24)
王紹容
;
Department of Communication and Technology
;
傳播與科技學系
芭蕾女伶穿著豔紅的舞鞋，腳步隨著音樂節拍快速變換，不斷旋轉、旋轉……直到發現自己停不下來。鮮血沾染了腳趾，但沒人看得見；大家只深深為她的舞姿所著迷，誰聽得見完美境界背後的一聲哀鳴？
外食族「鈉」麼傷身
(2013-02-24)
吳悅萍
;
Department of Communication and Technology
;
傳播與科技學系
現在有許多人由於外宿及用餐時間不固定，多選擇便利商店的外食，不過在選購食物時卻往往只注意標榜的低熱量、零卡，卻忽略了其中超標的鈉含量。長期攝取過量的鈉導致腎功能的衰敗，影響身體機能。
矽谷海盜　寶藏的掠奪者
(2013-02-24)
林妍君
;
Department of Communication and Technology
;
傳播與科技學系
鏡頭定格在一張會議桌，一群西裝筆挺的人正襟危坐，專注地聽著一位年輕人發表意見。這是整部影片中最具歷史意義的場景，地點在IBM總部的會議室，而那位年輕人後來成為21世紀最有影響力的人，他就是比爾蓋茲。
聽音樂的最佳選擇
(2013-02-24)
林伯勳
;
Department of Communication and Technology
;
傳播與科技學系
以節奏模仿心的悸動，用嗓音詮釋戀愛的心情，來自加拿大的女歌手Carly Rae Jepsen的〈Call Me Maybe〉一曲貼切地描寫，青春期的女生暗戀異性那心跳加速、充滿期待又怕受傷害的心情。