Browsing by Issue Date, starting with "2020-03-02"

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Eye Movement Analysis of Digital Learning Content for Educational Innovation
(2020-03-02)
Liu, Xiaolong
;
Zhang, Xuebai
;
Chen, Wei-Wen
;
Yuan, Shyan-Ming
;
資訊工程學系
Eye movement technology is highly valued for evaluating and improving digital learning content. In this paper, an educational innovation study of eye movement behaviors on digital learning content is presented. We proposed three new eye movement metrics to explain eye movement behaviors. In the proposed method, the digital content, which were slide-deck-like works, were classified into page categories according to the characteristics of each page. We interpreted the subjects' eye movement behaviors on the digital slide decks. After data regularization and filtering, the results were analyzed to give directions for how to design an attractive digital learning content from the viewpoint of eye movement behaviors. The relationships between the subjects' evaluation scores, page categories, and eye movement metrics are discussed. The results demonstrated that the proposed fixation time percentage (FTP) was a representative, strong, and stable eye movement metric to measure the subjects' interest. Moreover, a reasonable portion of semantic content had a positive influence on the subjects' interest.
Mult-Gbit/s phosphor-based white-light and blue-filter-free visible light communication and lighting system with practical transmission distance
(2020-03-02)
Wei, Liang-Yu
;
Chow, Chi-Wai
;
Liu, Yang
;
Yeh, Chien-Hung
;
光電工程學系
High speed visible light communication (VLC) is a technology with great potential for future mobile and wireless communication. Here, we report and demonstrate a 2.705 Gbit/s white-light VLC and illumination system supporting indoor transmission distance of 1.5 m, corresponding a illumination of 545 lux. We also study the performance tolerance offset ranges in both x- and y-directions. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Prescription AR: a fully-customized prescription-embedded augmented reality display
(2020-03-02)
Wu, Jui-Yi
;
Kim, Jonghyun
;
光電工程學系
;
Department of Photonics
In this paper, we present a fully-customized AR display design that considers the user's prescription, interpupillary distance, and taste of fashion. A free-form image combiner embedded inside the prescription lens provides augmented images onto the vision-corrected real world. The optics was optimized for each prescription level, which can reduce the mass production cost while satisfying the user's taste. The foveated optimization method was applied which distributes the pixels in accordance with human visual acuity. Our design can cover myopia, hyperopia, astigmatism, and presbyopia, and allows the eye-contact interaction with privacy protection. A 169g dynamic prototype showed a 40 degrees x 20 degrees virtual image with a 23 cpd resolution at center field and 6 mm x 4 mm eye-box, with the vision-correction and varifocal (0.5-3m) capability. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Enhanced quantum oscillations in Kondo insulators
(2020-03-02)
Lu, Yen-Wen
;
Chou, Po-Hao
;
Chung, Chung-Hou
;
Lee, Ting-Kuo
;
Mou, Chung-Yu
Quantum oscillations have long been regarded as the manifestation of the Fermi surface in metals. However, they were recently observed in Kondo insulators. We examine the Kondo screening due to Landau levels in Kondo insulators. It is shown that, even for large Kondo insulating gaps, appreciable amplitudes of quantum oscillations that are consistent with experimental observations are present both in magnetization and resistivity. Specifically, we show that, due to the periodic alignment between the Landau levels in the conduction and the f-orbit electrons, the Kondo screening itself undergoes oscillations so that the electronic structure oscillates with the magnetic field. Our results explain main features of quantum oscillations observed in experiments. They indicate that the nonrigidity of the electronic structure results in observable quantum oscillation Kondo insulators. This effect provides a way to probe the Fermi surface geometry of insulators.
Tensile Properties of < 111 >-Oriented Nanotwinned Cu with Different Columnar Grain Structures
(2020-03-02)
Li, Yu-Jin
;
Tu, King-Ning
;
Chen, Chih
;
材料科學與工程學系
;
國際半導體學院
We performed tensile tests on highly <111>-oriented nanotwinned copper (nt-Cu) foils with different columnar grain structures. For a systematic study, we altered the microstructure of the foils by tuning the electroplating electrolyte and annealing temperatures under a nitrogen atmosphere. The results show that the yield strength ranges from 300 to 700 MPa, and elongation spans from 5% to 25%. Knowing the measured twin spacing and average grain size, and combining the confined layer slip with the Hall-Petch equation, we calculated the theoretical yield strength of the nt-Cu with different microstructures, and the theoretic values match the experiment results. Owing to the unique crystal orientation properties of <111>-oriented columnar grains, dislocations induced by slip are very limited. The Schmid factor of grains along the tensile axis direction is highly identical, so the plastic deformation is much more suitably explained by the Schmid factor model. Thus, we replace the Taylor factor with the Schmid factor in the slip model of nt-Cu.
Nanowear Mechanisms of Mg Alloyed with Al and Y at Elevated Temperatures
(2020-03-03)
Gokhale, Aditya
;
Meena, Trapesh
;
Lee, Soo Yeol
;
Huang, E-Wen
;
Gosvami, Nitya N.
We examine the role of important alloying elements (Al, Y), on friction and wear mechanisms of Mg as a function of temperature. Friction and wear tests of Mg-5%Al and Mg-5%Y alloys performed at room temperature, 100 degrees C and 150 degrees C reveal that addition of Al and Y significantly reduces the coefficient of friction. However, despite higher hardness of Mg-5%Y alloy, its wear rate was found to be higher than Mg-5%Al alloy at elevated temperatures. We show that this behaviour, observed for Mg-5%Y alloy at elevated temperature, can be attributed to its higher surface energy than Mg-5%Al and pure Mg, leading to enhanced adhesive wear, which is detrimental to tribological applications.
Comparing PI3K/Akt Inhibitors Used in Ovarian Cancer Treatment
(2020-03-03)
Wu, Yi-Hui
;
Huang, Yu-Fang
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Chen, Chien-Chin
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Huang, Chia-Yen
;
Chou, Cheng-Yang
Epithelial ovarian carcinoma (EOC) is the most lethal gynecological malignancy. Herein, we sought to determine the efficacy of phosphoinositide 3-kinase (PI3K)/Akt inhibition using three AZD compounds in a NOD-SCID xenograft mouse model and Akt regulation in a panel of eight ovarian cancer cell lines. Elevated Akt phosphorylation on Ser473 but not on Thr308 in cancerous tissues correlated with short progression-free survival (PFS), overall survival (OS), and death. AZD8835 and AZD8186 inhibited Akt phosphorylation while AZD5363 augmented its phosphorylation on Ser473. To add, all compounds inhibited the Akt downstream effectors 4E-BP1 and p70S6 kinase. AZD8835 and AZD5363 sensitized chemoresistant ovarian cancer cells to cisplatin and paclitaxel treatment. Only AZD5363 could inhibit COL11A1 mRNA and promoter activity, which are important factors in Akt regulation and chemoresistance in ovarian cancer. By using a mouse xenograft model, AZD8835 and AZD5363, but not AZD8186, caused a significant reduction in tumor formation. AZD compounds did not change the mRNA expression of BRCA1/BRCA in ovarian cancer cells, but AZD8835 inhibited BRCA1/BRCA2 mRNA expression and p-ERK protein expression in OVCAR-8 cells with the KRAS mutation. This study highlights the importance of PI3K/Akt in ovarian tumor progression and chemoresistance and the potential application of AZD compounds, especially AZD8835 and AZD5363, as therapeutic agents for the treatment of ovarian cancer.
Multi-Stimuli Responsive FRET Processes of Bifluorophoric AlEgens in an Amphiphilic Copolymer and Its Application to Cyanide Detection in Aqueous Media
(2020-03-04)
Nhien, Pham Quoc
;
Chou, Wei-Lun
;
Cuc, Tu Thi Kim
;
Khang, Trang Manh
;
Wu, Chia-Hua
A novel amphiphilic aggregation-induced emission (AIE) copolymer, that is, poly(NIPAM-co-TPE-SP), consisting of N-isopropylacrylamide (NIPAM) as a hydrophilic unit and a tetraphenylethylene-spiropyran monomer (TPE-SP) as a bifluorophoric unit is reported. Upon UV exposure, the close form of non-emissive spiropyran (SP) in poly(NIPAM-co-TPE-SP) can be photo-switched to the open form of emissive merocyanine (MC) in poly(NIPAM-co-TPE-MC) in an aqueous solution, leading to ratiometric fluorescence of AlEgens between green TPE and red MC emissions at 517 and 627 nm, respectively, via Forster resonance energy transfer (FRET). Distinct FRET processes of poly(NIPAM-co-TPE-MC) can be observed under various UV and visible light irradiations, acid-base conditions, thermal treatments, and cyanide ion interactions, which are also confirmed by theoretical studies. The subtle perturbations of environmental factors, such as UV exposure, pH value, temperature, and cyanide ion, can be detected in aqueous media by distinct ratiometric fluorescence changes of the FRET behavior in the amphiphilic poly(NIPAM-co-TPE-MC). Moreover, the first FRET sensor polymer poly(NIPAM-co-TPE-MC) based on dual AlEgens of TPE and MC units is developed to show a very high selectivity and sensitivity with a low detection limit (LOD = 0.26 mu M) toward the cyanide ion in water, which only contain an approximately 1% molar ratio of the bifluorophoric content and can be utilized in cellular bioimaging applications for cyanide detections.
Controlled synthesis and CO sensing potentials of size-tunable highly-uniform mesoporous Co3O4 nanospheres
(2020-03-05)
Chen, Kuan-Wei
;
Tsai, Ju-Heng
;
Chen, Chun-Hua
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A series of highly-uniform and mesoporous Co3O4 nanospheres comprising porously-assembled tiny building blocks, and more importantly, with widely tunable sizes from 50 nm up to 500 nm were successfully synthesized for the first time via single facile polyol approach. The crucial synthesizing factors including molecular weight and concentrations of polyvinylpyrrolidone, the fraction of cobalt precursor, and the subsequent calcination temperature and time were systematically varied over a very wide range for extensively understanding their effects on growth mechanisms, uniformity and particularly the minimum assembled size. The present unique mesoporous nanoassemblies evidently lead to not only a higher surface-to-volume ratio for a variety of potential applications but a lower operating temperature for CO sensing compared with that reported for a variety of intrinsic or heterogeneous Co3O4 nanostructures. (C) 2019 Elsevier B.V. All rights reserved.
Virtual-freezing fluorescence imaging flow cytometry
(2020-03-06)
Mikami, Hideharu
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Kawaguchi, Makoto
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Huang, Chun-Jung
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Matsumura, Hiroki
;
Sugimura, Takeaki
By virtue of the combined merits of flow cytometry and fluorescence microscopy, imaging flow cytometry (IFC) has become an established tool for cell analysis in diverse biomedical fields such as cancer biology, microbiology, immunology, hematology, and stem cell biology. However, the performance and utility of IFC are severely limited by the fundamental trade-off between throughput, sensitivity, and spatial resolution. Here we present an optomechanical imaging method that overcomes the trade-off by virtually freezing the motion of flowing cells on the image sensor to effectively achieve 1000 times longer exposure time for microscopy-grade fluorescence image acquisition. Consequently, it enables high-throughput IFC of single cells at >10,000 cells s(-1) without sacrificing sensitivity and spatial resolution. The availability of numerous information-rich fluorescence cell images allows high-dimensional statistical analysis and accurate classification with deep learning, as evidenced by our demonstration of unique applications in hematology and microbiology. High throughput imaging flow cytometry suffers from trade-offs between throughput, sensitivity and spatial resolution. Here the authors introduce a method to virtually freeze cells in the image acquisition window to enable 1000 times longer signal integration time and improve signal-to-noise ratio.
Polydopamine and Its Composite Film as an Adhesion Layer for Cu Electroless Deposition on SiO2
(2020-03-09)
Chou, Shih-Cheng
;
Chung, Wei-An
;
Fan, Tzu-Ling
;
Dordi, Yezdi
;
Koike, Junichi
We explore dopamine (DA) and its mixtures with polyethylene glycol (PEG) or polyethylenimine (PEI) as an adhesion layer for bonding between Cu and SiO2. The DA is oxidized to form polydopamine (PDA) which deposits as aggregates on SiO2 surface with notable surface roughness. After mixing with PEG or PEI, the morphology of PDA aggregates is altered considerably. Electroless Cu deposition in a mild alkaline bath is employed to deposit Cu atop the adhesion layer. The Cu films reveal an fcc lattice with (111) preferred orientation and their thickness was around 650 nm. From measurements of four-point probe, breaking strength, and tape-peeling tests, the PDA/PEG mixture reveals impressive performance serving as a strong adhesive for robust Cu bonding. We attribute the unique adhesive ability of PDA/PEG to the hydrogen bonds established between the catechol and amine groups of DA with PEG that renders desirable film formation on the SiO2 surface for optimized interaction between Cu and SiO2. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.
Easy-cone magnetic structure in (Cr0.9B0.1)Te
(2020-03-09)
He, Yangkun
;
Fecher, Gerhard H.
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Kroder, Johannes
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Borrmann, Horst
;
Wang, Xiao
Although stoichiometric CrTe is difficult to synthesize because of the appearance of Cr vacancies, ferromagnetic Cr1-x Te compounds have attracted increasing attention. This work investigates single crystalline (Cr-0.9 B-0.1)Te with the Cr vacancies filled by B to stabilize the hexagonal crystal structure and shift the Fermi energy. The structural and magnetic properties have been characterized by experimental measurements and ab initio calculations. A collinear spin structure with an easy axis along c is observed at high temperature, whereas the magnetic moments localized at the Cr atoms gradually tilt away from the c-axis below 140K. A maximum tilt angle of 30 degrees is observed at a temperature of 2K. (C) 2020 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http:// creativecommons.org/licenses/by/4.0/).
Putative Abscopal Effect in Three Patients Treated by Combined Radiotherapy and Modulated Electrohyperthermia
(2020-03-10)
Chi, Mau-Shin
;
Mehta, Minesh P.
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Yang, Kai-Lin
;
Lai, Hung-Chih
;
Lin, Ying-Chu
Purpose: True abscopal responses from radiation therapy are extremely rare; the combination of immune checkpoint inhibitors with radiation therapy has led to more reports of the abscopal effect, but even in this setting, the genuine magnitude remains unknown and is still considered generally uncommon. We report the occurrence of what appears to be putative, durable abscopal tumor responses with associated auto-immune systemic reactions resulting from the combination of local radiotherapy (RT) and modulated electrohyperthermia (mEHT). Materials and Methods: Data from advanced cancer patients treated palliatively with RT and mEHT between January and December 2017 were collected as part of a post-marketing safety monitoring program of mEHT therapy. We specified a minimum RT dose of 30 Gy and at least four mEHT treatments for reporting toxicities, which was the primary aim of the larger study. Results: Thirty-three patients treated with RT and mEHT, both applied to the same lesion, were included. The median RT dose was 45.5 Gy in 20 fractions (fxs) and the median number of mEHT treatments was 12 (range, 4-20). Most patients had subsequent systemic therapy after one course of RT and mEHT. Three patients (9.1%) developed autoimmune toxicities. Case number 1 received RT and mEHT only; case number 2 had two cycles of concurrent low dose chemotherapy during RT; and case number 3 received concurrent immune checkpoint inhibitors. None of the three patients received any further systemic treatment due to obvious treatment-related autoimmune reactions which occurred rapidly after RT; one had autoimmune hepatitis, one had dermatitis herpetiformis and the third developed severe myasthenia gravis. Interestingly, what we surmise to be long-lasting abscopal responses outside the irradiated area, were noted in all three patients. Conclusion: RT combined with mEHT could putatively result in enhancing immune responsiveness. These preliminary observational findings lead to the generation of a hypothesis that this combination induces both an in-situ, tumor-specific immune reaction and an anti-self-autoimmune reaction, in at least a small proportion of patients, and of those who experience the auto-immune response, tumor response is a concomitant finding. Mechanisms underlying this phenomenon need to be investigated further.
Plasma-Induced Exfoliation Provides Onion-Like Graphene-Surrounded MoS2 Nanosheets for a Highly Efficient Hydrogen Evolution Reaction
(2020-03-11)
Nguyen, Van-Truong
;
Le, Phuoc Anh
;
Hsu, Yung-Chi
;
Wei, Kung-Hwa
;
交大名義發表
With the goal of obtaining sustainable earth-abundant electrocatalyst materials displaying high performance in the hydrogen evolution reaction (HER), here we propose a facile one-pot plasma-induced electrochemical process for the fabrication of new core-shell structures of ultrathin MoS2 nanosheets engulfed within onion-like graphene nanosheets (OGNs@MoS2). The resultant OGNs@MoS2 structures not only increased the number of active sites of the semiconducting MoS2 nanosheets but also enhanced their conductivity. Our OGNs@MoS2 composites exhibited high HER performance, characterized by a low overpotential of 118 mV at a current density of 10 mA cm(-2), a Tafel slope of 73 mV dec(-1), and long-time stability of 10(5) s without degradation; this performance is much better than that of the sheet-like graphene-wrapped MoS2 composite GNsgMoS(2) (182 mV, 82 mV dec(-1)) and is among the best ever reported for composites involving MoS2 and graphene nanosheets prepared through a simple one-batch process and using a low temperature and a short time for the HER. This approach appears to be an effective and simple strategy for tuning the morphologies of composites of graphene and transition metal dichalcogenide materials for a broad range of energy applications.
Atomic Imaging of Molybdenum Oxide Nanowires with Unique and Complex Periodicity by Advanced Electron Microscopy
(2020-03-11)
Ting, Yi-Hsin
;
Huang, Chun-Wei
;
Yasuhara, Akira
;
Chen, Sheng-Yuan
;
Chen, Jui-Yuan
Crystalline Mo5O14 exhibits distinctive structural features such as tunnel structure and pseudolamellar arrangement according to the ideal model. However, the spatial resolution of the conventional technique of transmission electron microscopy (TEM) is insufficient to distinguish the actual positions of atoms. In this work, we aimed to systematically analyze and identify the Mo5O14 nanowires fabricated by the chemical vapor deposition (CVD) process. Utilizing high-angle annular dark-field (HAADF), annular bright-field (ABF), and enhanced annular bright-field (E-ABF) within the scanning transmission electron microscope (STEM) mode reveals the structural features at the atomic scale. In addition, the ultrahigh resolution images have confirmed the crystallographic insights in [001] growth direction for the Mo5O14 nanowires with a tunnel structure throughout the nanowire. The cross-sectional images show the unique close-packed plane and atomic arrangement with a network of MoO6 octahedra and MoO7 pentagonal bipyramids. These results are consistent with the theoretical atomic arrangement, supporting the realization of Mo5O14-type catalysts used in the selective oxidation process and battery applications.
【動物飼養管理課程】
(國立陽明大學, 2020-03-13)
陽明電子報編輯小組
陽明攜手遠雄，打造自貿區國際醫療中心
(國立陽明大學, 2020-03-13)
陽明電子報編輯小組
陽明與遠雄自由貿易港區股份有限公司2月27日簽署「國際醫療暨生技產業發展合作備忘錄」，將以遠雄自由貿易港區為基地，共同打造自...
Cholesteryl alpha-D-glucoside 6-acyltransferase enhances the adhesion of Helicobacter pylori to gastric epithelium
(2020-03-13)
Jan, Hau-Ming
;
Chen, Yi-Chi
;
Yang, Tsai-Chen
;
Ong, Lih-Lih
;
Chang, Chia-Chen
Helicobacter pylori, the most common etiologic agent of gastric diseases including gastric cancer, is auxotrophic for cholesterol and has to hijack it from gastric epithelia. Upon uptake, the bacteria convert cholesterol to cholesteryl 6 '-O-acyl-alpha-D-glucopyranoside (CAG) to promote lipid raft clustering in the host cell membranes. However, how CAG appears in the host to exert the pathogenesis still remains ambiguous. Herein we identified hp0499 to be the gene of cholesteryl alpha-D-glucopyranoside acyltransferase (CGAT). Together with cholesteryl glucosyltransferase (catalyzing the prior step), CGAT is secreted via outer membrane vesicles to the host cells for direct synthesis of CAG. This significantly enhances lipid rafts clustering, gathers adhesion molecules (including Lewis antigens and integrins alpha 5, beta 1), and promotes more bacterial adhesion. Furthermore, the clinically used drug amiodarone was shown as a potent inhibitor of CGAT to effectively reduce the bacterial adhesion, indicating that CGAT is a potential target of therapeutic intervention. Jan et al. identify cholesteryl alpha-D- glucopyranoside acyltransferase as a key enzyme in Helicobacter pylori's synthesis of cholesteryl 6'-O-acyl-alpha-D-glucopyranoside, which promotes bacterial adhesion. This study provides insights into the H. pylori-induced pathogenesis and therapeutic strategies against it.
【陽明九景文學與攝影獎】
(國立陽明大學, 2020-03-13)
陽明電子報編輯小組
加強校園防疫，將採體溫量測與線上授課
(國立陽明大學, 2020-03-13)
陽明電子報編輯小組
因應武漢新型冠狀病毒疫情升溫，本校防疫小組3月9日決議，在人潮眾多的學餐一樓，將採用紅外線熱像儀全面量測體溫。同時，若校園...