Browsing by Issue Date, starting with "2017-12-25"

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Femtosecond laser-colorized indium-tin-oxide films for blue light attenuation and image screening
(2017-12-25)
Tseng, Ya-Hsin
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Yang, Hung
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Luo, Chih-Wei
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電子物理學系
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Department of Electrophysics
Laser-colorized indium-tin-oxide (ITO) films are fabricated using femtosecond laser processing. By varying the laser fluences, nanostructures with cotton, brick and ripple forms are generated on the surface of ITO films, which produces cyan, yellow and orange colors. The fluence-dependent nanostructures on the surface of ITO films also significantly attenuates blue light so these materials are suited to eye protection and the screening of images behind ITO films for information security. (C) 2017 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Electrically injected 1.3-mu m quantum-dot photonic-crystal surface-emitting lasers
(2017-12-25)
Hsu, Ming-Yang
;
Lin, Gray
;
Pan, Chien-Hung
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
We have fabricated electrically injected InAs/InGaAs/GaAs quantum-dot (QD) photonic-crystal (PC) surface-emitting lasers (SELs) and successfully demonstrated roomtemperature lasing emissions at 1.3-mu m wavelength for the first time. The PCSEL device fabrication was greatly simplified by deposition of transparent conducting layer of indiumtin- oxide over "PC slab-on-substrate" structure. The threshold current density per QD layer was as low as 50 A/cm(2)/layer; however, the optical output was limited to 2 mW. The bandedge lasing mode was identified and near-circular beam with narrow divergence angle less than 2 degrees was achieved. (C) 2017 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Light-driven nanofiber and nanoring morphological transformations in organogels based on an azobenzene-bridged biscalix[4]arene
(2017-12-25)
Su, Pei-Mei
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Chang, Kai-Chi
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Yang, Cheng-Jhang
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Liu, Yi-Chieh
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Chung, Wen-Sheng
The morphologies of an azobenzene-bridged biscalix[4]arene organogel in different organic solvents can be photo-reversibly switched between nanofibers and nanorings as well as between closed and open-form vesicles.
Constraining the mass scale of a Lorentz-violating Hamiltonian with the measurement of astrophysical neutrino-flavor composition
(2017-12-26)
Lai, Kwang-Chang
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Lai, Wei-Hao
;
Lin, Guey-Lin
;
物理研究所
;
Institute of Physics
We study Lorentz violation effects on flavor transitions of high energy astrophysical neutrinos. It is shown that the appearance of a Lorentz-violating Hamiltonian can drastically change the flavor transition probabilities of astrophysical neutrinos. Predictions of Lorentz-violation effects on flavor compositions of astrophysical neutrinos arriving on Earth are compared with IceCube flavor composition measurement which analyzes astrophysical neutrino events in the energy range between 25 TeV and 2.8 PeV. Such a comparison indicates that the future IceCube-Gen2 will be able to place stringent constraints on a Lorentz-violating Hamiltonian in the neutrino sector. We work out the expected sensitivities by IceCube-Gen2 on dimension-3 CPT-odd and dimension-4 CPT-even operators in a Lorentz-violating Hamiltonian. The expected sensitivities can improve on the current constraints obtained from other types of experiments by more than two orders of magnitudes for certain ranges of the parameter space.
Helicobacter pylori CagA protein activates Akt and attenuates chemotherapeutics-induced apoptosis in gastric cancer cells
(2017-12-26)
Lan, Keng-Hsueh
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Lee, Wei-Ping
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Wang, Yu-Shan
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Liao, Shi-Xian
;
Lan, Keng-Hsin
Infection with cagA-positive Helicobacter pylori is associated with a higher risk of gastric cancer. The cagA gene product, CagA, is translocated into gastric epithelial cells and perturbs host cellular biological functions. Etoposide, a topoisomerase II inhibitor widely used to couple DNA damage to apoptosis, is a common cytotoxic agent used for advanced gastric cancer. We investigate the effect of CagA on etoposide-induced apoptosis in gastric cancer cells to elucidate whether CagA play a role in gastric carcinogenesis via impairing DNA damage-dependent apoptosis. AGS cell lines stably expressing CagA isolated from H. pylori 26695 strain were established. In the presence of etoposide, viability of parental AGS cells was decreased in a time-and dose-dependent manner, whereas CagA-expressing AGS cells were less susceptible to etoposide induced cell-killing effect. Suppression of etoposide-induced apoptosis was shown in CagA-expressing but not in parental AGS cells by DNA fragmentation, cell cycle, and annexin-V assays. This inhibitory effect of etoposide-induced apoptosis conferred by CagA was also demonstrated in SCM1 and MKN45 gastric cancer cell lines, with two additional chemotherapeutics, 5-FU and cisplatin. The effect of Akt activation on inhibition of etoposide-induced cytotoxicity by CagA was also evaluated. CagA expression and etoposide administration activate Akt in a dose-dependent manner. Enhancement of etoposide cytotoxicity by a PI-3-kinase inhibitor, LY294002, was evident in parental but was attenuated in CagA-expressing AGS cells. CagA may activate Akt, either in the absence or presence of etoposide, potentially contributing to gastric carcinogenesis associated with H. pylori infection and therapeutic resistance by impairing DNA damage-dependent apoptosis.
Using multi-ring structure for suppression of mode competition in stable single-longitudinal-mode erbium fiber laser
(2017-12-28)
Yeh, Chien-Hung
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Huang, Tzu-Jung
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Yang, Zi-Qing
;
Chow, Chi-Wai
;
光電工程學系
In this demonstration, a stable and tunable single-longitudinal-mode (SLM) erbium-doped fiber (EDF) laser with multiple-ring configuration is proposed and investigated. The proposed compound-ring structure can create different free spectrum ranges (FSRs) to result in the modefilter effect based on the Vernier effect for suppressing the other modes. Additionally, the output stabilization of power and wavelength in the proposed EDF multiple-ring laser are also discussed.
METHOD FOR ADJUSTING EXPOSURE OF CAMERA DEVICE
(2017-12-28)
Jiun-In GUO
;
Po-Hsiang HUANG
A method for adjusting exposure of a camera device is provided to include steps of: using first to Mth camera modules to continuously capture images in sync; reducing an exposure value of the first camera module according to a first current image captured at a latest time point by the first camera module until a first condition associated with the first current image is met; adjusting an exposure value of an ith camera module according to an ith current image, which is captured at the latest time point by the ith camera module, and an (i-1)th previous image, which is captured at a time point immediately previous to the latest time point by an (i-1)th camera module.
SELF-ASSEMBLED NANOSTRUCTURE AND METHOD FOR PREPARING THE SAME
(2017-12-28)
Ting-Yu Kuo
;
Wei-Ting Huang
;
Dean-Mo Liu
A self-assembled nanostructure including an amphiphilic chitosan and a contrast agent compound is provided. The contrast agent compound is grafted to the amphiphilic chitosan. The chemical bonding between the amphiphilic chitosan and the contrast agent compound has a synergistic effect to further improve the contrasting ability of the contrast agent compound.
Pharmacophore anchor models of flaviviral NS3 proteases lead to drug repurposing for DENV infection
(2017-12-28)
Pathak, Nikhil
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Lai, Mei-Ling
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Chen, Wen-Yu
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Hsieh, Betty-Wu
;
Yu, Guann-Yi
Background: Viruses of the flaviviridae family are responsible for some of the major infectious viral diseases around the world and there is an urgent need for drug development for these diseases. Most of the virtual screening methods in flaviviral drug discovery suffer from a low hit rate, strain-specific efficacy differences, and susceptibility to resistance. It is because they often fail to capture the key pharmacological features of the target active site critical for protein function inhibition. So in our current work, for the flaviviral NS3 protease, we summarized the pharmacophore features at the protease active site as anchors (subsite-moiety interactions). Results: For each of the four flaviviral NS3 proteases (i.e., HCV, DENV, WNV, and JEV), the anchors were obtained and summarized into 'Pharmacophore anchor (PA) models'. To capture the conserved pharmacophore anchors across these proteases, were merged the four PA models. We identified five consensus core anchors (CEH1, CH3, CH7, CV1, CV3) in all PA models, represented as the "Core pharmacophore anchor (CPA) model" and also identified specific anchors unique to the PA models. Our PA/CPA models complied with 89 known NS3 protease inhibitors. Furthermore, we proposed an integrated anchor-based screening method using the anchors from our models for discovering inhibitors. This method was applied on the DENV NS3 protease to screen FDA drugs discovering boceprevir, telaprevir and asunaprevir as promising anti-DENV candidates. Experimental testing against DV2-NGC virus by in-vitro plaque assays showed that asunaprevir and telaprevir inhibited viral replication with EC50 values of 10.4 mu M & 24.5 mu M respectively. The structure-anchor-activity relationships (SAAR) showed that our PA/CPA model anchors explained the observed in-vitro activities of the candidates. Also, we observed that the CEH1 anchor engagement was critical for the activities of telaprevir and asunaprevir while the extent of inhibitor anchor occupation guided their efficacies. Conclusion: These results validate our NS3 protease PA/CPA models, anchors and the integrated anchor-based screening method to be useful in inhibitor discovery and lead optimization, thus accelerating flaviviral drug discovery.
Strong magnetic field induces superconductivity in a Weyl semimetal
(2017-12-29)
Rosenstein, Baruch
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Shapiro, B. Ya.
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Li, Dingping
;
Shapiro, I.
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電子物理學系
Microscopic theory of the normal-to-superconductor coexistence line of a multiband Weyl superconductor subjected to magnetic field is constructed. It is shown that the Weyl semimetal that is nonsuperconducting or having a small critical temperature T-c at zero field might become a superconductor at higher temperatures when the magnetic field is tuned to a series of quantized values H-n. The pairing occurs on Landau levels. It is argued that the phenomenon is detectable much easier in Weyl semimetals than in parabolic band metals since the quantum limit already has been approached in several Weyl materials. The effect of Zeeman coupling leading to splitting of the reentrant superconducting regions on the magnetic phase diagram is considered. An experimental signature of the superconductivity on Landau levels is the reduction of magnetoresistivity. This has been observed already in Cd3As2 and several other compounds. The novel kind of quantum oscillations of magnetoresistance detected in ZrTe5 is discussed along these lines.
學術倫理　道德迷失的象牙塔
(2017-12-31)
謝宛蓁
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Department of Communication and Technology
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傳播與科技學系
論文造假是臺灣學術界的醜態也是常態，制度導致的結構性問題促使違反學術倫理的案件頻傳。在這些論文造假案被當作醜聞炒作一番後，政府將學術倫理的問題寄託於教育之上，真的會有幫助嗎？
Analysis of abnormal transconductance in body-tied partially-depleted silicon-on-insulator n-MOSFETs
(2017-12-31)
Lin, Chien-Yu
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Chang, Ting-Chang
;
Liu, Kuan-Ju
;
Chen, Li-Hui
;
Chen, Ching-En
This research investigates the mechanism of abnormal transconductance (Gm) and abnormal charge pumping current (I-CP) in body-tied partially-depleted silicon-on-insulator n-channel metal-oxide-semiconductor field effect transistors. The I-CP second hump region increases with channel length, yet is not affected by channel width. The cross-sectional view of the L-gate structure along the width direction demonstrates that a part of the poly gate area near the body contact is covered by a P+ implant, inducing a parasitic channel under the P+ poly gate. This parasitic channel leads to the abnormal Gm and I-CP hump, and such mechanism is further verified by body floating devices.
反勞基法遊行　來自底層的怒吼
(2017-12-31)
黃昱晉
;
鄭仰珉
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Department of Communication and Technology
;
傳播與科技學系
反勞基法大遊行在12月23日盛大展開，透過遊行、演說向政府與民眾表達對此法案的不滿。
總編輯的話
(2017-12-31)
楊佩臻
;
Department of Communication and Technology
;
傳播與科技學系
本期為喀報281期，稿件共計12篇，以社會議題居多。本期頭題為「病人自主　決定生命最後一哩路」，透過即將於2019年實施的《病人自主權利法》，讓大家更加了解人權與善終等議題。
「人生是種選擇」——Serene
(2017-12-31)
游允彤
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Department of Communication and Technology
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傳播與科技學系
用一顆不斷挑戰自我的心，建立一個時尚、知性兼具的YouTube頻道。
更自由的人生　斜槓青年
(2017-12-31)
范晨星
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Department of Communication and Technology
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傳播與科技學系
「斜槓青年」一詞在2007年被提出，它到底是什麼意思，這個概念到現在又經過了甚麼變化呢？
國片難起飛　映演問題多？
(2017-12-31)
馮瑜庭
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Department of Communication and Technology
;
傳播與科技學系
國片長期受到好萊塢的壓制，究竟制度上產生甚麼問題導致台灣電影無法翻身？爭論多時的映演比率若實施是否能真正改善現況？
神轎製作　王永川的一甲子歲月
(2017-12-31)
吳佩芸
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Department of Communication and Technology
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傳播與科技學系
台灣國寶級老師傅——王永川先生走過的心路歷程。
Endurance improvement and resistance stabilization of transparent multilayer resistance switching devices with oxygen deficient WOx layer and heat dissipating AlN buffer layer
(2017-12-31)
Lin, Yu-Hsuan
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Huang, Ding-Chiuan
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Lou, Jen-Chung
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Tseng, Tseung-Yuen
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電子工程學系及電子研究所
In this study, indium tin oxide (ITO), zinc oxide (ZnO), tungsten oxide (WOx), and aluminum nitride (AlN) were employed to fabricate and investigate four transparent resistive random access memory (ReRAMs) structures: ITO/ZnO/ITO (structure 1), ITO/WO3/ZnO/ITO (structure 2), ITO/WOx(x < 3)/WO3/ZnO/ITO (structure 3), and ITO/WOx(x < 3)/WO3/ZnO/AlN/ITO (structure 4). Structure 4 exhibited less variation in low-resistance states, lower operating voltages, and higher endurance compared with other structures. This phenomenon was attributed to the oxygen-deficient WOx layer in structure 4, which acted as an oxygen ion reservoir for efficient resistive changes, and the WO3 layer limited the filament rupture and formation region. Moreover, the high thermal conductivity of the AlN layer alleviated the thermally activated ion movement of the ReRAM and strengthened the high-resistance state. Structure 4 was found to be the optimal structure, with median operating voltages 1.6 V for SET operations and -1.0 V for RESET operations, retention of > 10(4) s at 200 degrees C, and endurance of 10(4) cycles with a resistance ratio of over 20. Structure 4 exhibited extremely high stability in both low- and high-resistance states during cycling. The transmittance of structure 4 was 85.49%, which is suitable for optoelectronic applications.
陰道放音樂　胎教更有用？
(2017-12-31)
林明慧
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Department of Communication and Technology
;
傳播與科技學系
在陰道播放音樂可以讓胎兒聽得更清楚？本文將帶領讀者了解胎兒如何聽見外界的聲音，並且介紹2017搞笑諾貝爾婦產科學獎的研究。