Browsing by Issue Date, starting with "2020-07-22"

Now showing 1 - 20 of 4613

Manipulation of Nitrogen-Heteroatom Configuration for Enhanced Charge-Storage Performance and Reliability of Nanoporous Carbon Electrodes
(2020-07-22)
Sutarsis
;
Patra, Jagabandhu
;
Su, Ching-Yuan
;
Li, Ju
;
Bresser, Dominic
In this study, various nitrogen-containing functional groups, namely, pyridine (N-6), pyrrole (N-5), oxidized N (N-O), and quaternary N (N-Q), are created on activated carbon (AC) surface via melamine, ammonia, and nitric oxide doping methods. N-5 and N-6 groups markedly alter the specific surface area and pore size of AC. N-O is found to affect electrolyte wettability, and the N-Q content is closely associated with AC electronic conductivity. The nitrogen-containing groups do not contribute to pseudocapacitance in propylene carbonate and acetonitrile electrolytes. However, the nitric-oxide-treated carbon (AC-NO) exhibits the best highrate charge-discharge performance among the investigated materials. The N-Q-enriched and N-5/N-6-depleted AC-NO most effectively suppresses the leakage current and gas evolution of supercapacitors. Online gas chromatography is used to analyze the gaseous species produced from AC electrodes. With an appropriate surface functionality on carbon, the cell voltage can be increased to similar to 3 V, increasing the energy and power densities. The aging behavior of the carbon electrodes with and without nitrogen modification after being floated at 2.5 V and 70 degrees C for 3 days is investigated. An effective strategy for enhancing supercapacitor performance and reliability is proposed.
Label-Free Bimetallic In Situ-Grown 3D Nickel-Foam-Supported NH2-MIL-88B(Fe2Co)-MOF-based Impedimetric Immunosensor for the Detection of Cardiac Troponin I
(2020-07-22)
Palanisamy, Sathyadevi
;
Raja, Duraisamy Senthil
;
Subramani, Boopathi
;
Wu, Tung-Ho
;
Wang, Yun-Ming
In this study, a simple and competent metal-organic framework (MOF)-based nickel foam (NF)-supported three-dimensional (3D) immunosensor (Ab-NH2-MIL-88B-(Fe2Co)-MOF/NF) was constructed and utilized for the specific recognition of the biomarker cardiac troponin (I) (cTnI). In the present work, biosensor fabrication was progressed through the modification of the NF substrate with the MOF material (NH2-MIL-88B(Fe2Co)-MOF) to enable an amine-functionalized electrode. This amine-functionalized NF electrodes (NH2-MIL-88B(Fe2Co)-MOF/NF) were then biointerfaced with anti-cTnI antibodies, which ended up as Ab-NH2-MIL-88B(Fe2Co)-MOF/NF electrodes. Analytical executions of the constructed bioelectrode were investigated for the quantitative analysis of cTnI in both buffered and serum solutions. Then, the electrochemical studies were carried out using the electrochemical impedance spectroscopy (EIS) method by monitoring changes concerning the charge transfer resistance (R-ct) characteristics. The limit of detection (LOD) of the Ab-NH2-MIL-88B(Fe2Co)-MOF/NF immunosensor was achieved to be 13 fg/mL with great specificity. This kind of immunosensor imparts a new platform for the construction and application of MOF-hybrid 3D electrode materials with enhanced electrochemical behavior in cTnI sensing for the first time.
The Anastomotic Angle of Hemodialysis Arteriovenous Fistula Is Associated With Flow Disturbance at the Venous Stenosis Location on Angiography
(2020-07-23)
Yang, Chih-Yu
;
Li, Ming-Chia
;
Lan, Chien-Wen
;
Lee, Wang-Jiun
;
Lee, Chen-Ju
The juxta-anastomotic stenosis of an arteriovenous fistula (AVF) is a significant clinical problem in hemodialysis patients with no effective treatment. Previous studies of AV anastomotic angles on hemodynamics and vascular wall injury were based on computational fluid dynamics (CFD) simulations using standardized AVF geometry, not the real-world patient images. The present study is the first CFD study to use angiographic images with patient-specific outcome information, i.e., the exact location of the AVF stenotic lesion. We conducted the CFD analysis utilizing patient-specific AVF geometric models to investigate hemodynamic parameters at different locations of an AVF, and the association between hemodynamic parameters and the anastomotic angle, particularly at the stenotic location. We analyzed 27 patients who used radio-cephalic AVF for hemodialysis and received an angiographic examination for juxta-anastomotic stenosis. The three-dimensional geometrical model of each patient's AVF was built using the angiographic images, in which the shape and the anastomotic angle of the AVF were depicted. CFD simulations of AVF hemodynamics were conducted to obtain blood flow parameters at different locations of an AVF. We found that at the location of the stenotic lesion, the AV angle was significantly correlated with access flow disturbance (r= 0.739;p< 0.001) and flow velocity (r= 0.563;p= 0.002). Furthermore, the receiver operating characteristic (ROC) curve analysis revealed that the AV angle determines the lesion's flow disturbance with a high area under the curve value of 0.878. The ROC analysis also identified a cut-off value of the AV angle as 46.5 degrees, above or below which the access flow disturbance was significantly different. By applying CFD analysis to real-world patient images, the present study provides evidence that an anastomotic angle wider than 46.5 degrees might lead to disturbed flow generation, demonstrating a reference angle to adopt during the anastomosis surgery.
Hybrid Composites of Quantum Dots, Monolayer WSe2, and Ag Nanodisks for White Light-Emitting Diodes
(2020-07-24)
Chang, Chiao-Yun
;
Yu, Cheng-Li
;
Lin, Chen-An
;
Lin, Hsiang-Ting
;
Lee, Andrew Boyi
We investigated hybrid zero-dimensional core-shell CdSe/ZnS quantum dot (QD)/two-dimensional monolayer WSe2 semiconductors with an Ag nanodisk (ND) for manipulating plasmonic-enhanced photoluminescence (PL) and color conversion efficiency. The absorption spectrum of the local surface plasmon resonance (LSPR) effectively overlaps with that of QDs or monolayer WSe2 to considerably enhance PL. The broad absorption spectrum of the LSPR simultaneously overlapped with the emission spectrum of QDs and the absorption spectrum of excitons in WSe2 to enhance the color conversion efficiency. The highest efficiency of color conversion from QDs to WSe2 with Ag ND was 53%. In the future, hybrid QD/transition metal dichalcogenide light emitters could be further integrated with GaN-based white light-emitting diodes to manipulate the color temperature and expand the color gamut to develop a miniature white light-emitting diode.
Heteroepitaxial growth and microwave plasma annealing of DC reactive sputtering deposited TiZrN film on Si (100)
(2020-07-25)
Chiu, Kun-An
;
Fu, Chia-Wei
;
Fang, Yu-Siang
;
Thi Hien Do
;
Shih, Fu-Han
Epitaxial TiZrN films were successfully grown on Si (100) substrates at high temperature by using DC magnetron reactive sputtering with a Ti0.68Zr0.32 alloy target. Annealing of a grown TiZrN/Si specimen was performed by applying microwave plasma with a gas mixture of N-2 and H-2 to improve the film quality. The X-ray rocking curve (XRC) width of (200)(TiZrN) reflection can reach a minimum value of 1.18 degrees. The heteroepitaxial relationship of TiZrN with Si is {001}(TiZrN)//{001}(Si) and < 110 >(TiZrN)//< 110 >(Si). The (200)(TiZrN) XRC width of a 20 nm-thick TiZrN film reduces from 1.99 degrees to 0.85 degrees by microwave plasma annealing. As a result of the improvement of the film quality, the annealed film exhibits a much lower resistivity (28 mu Omega.cm) than that of the as-deposited one (44 mu Omega.cm). The surface morphologies of the TiZrN films are smooth with the surface roughness in the range of 1-2 nm.
Characteristic V-Mn conversion coating in reinforcing corrosion resistance of electroless Ni-P coated LZ91 Mg alloy
(2020-07-25)
Jian, Shun-Yi
;
Chang, Jun-Kai
;
Lin, Kung-Feng
;
Chen, Ting-Yu
;
Yuan, Jui-Hung
A V-Mn conversion coating was studied and furthermore employed to improve the corrosion resistance of electroless Ni-P coated LZ91 Mg alloy. A thin, continuous and compact V-Mn conversion coating was formed on LZ91 after the immersion of 60 s in the conversion coating solution. The results of electrochemical impedance spectroscopy (EIS) and salt spray test (SST) showed the enhanced corrosion resistance of LZ91. The impedance in EIS increased from 573 Omega.cm(2) to 11,319 Omega.cm(2), and moreover the deteriorated area ratio of the V-Mn conversion coated LZ91 decreased to < 5% after 120 h of SST exposures. Further study of a V-Mn conversion coating/electroless Ni-P composite coated LZ91 was used to investigate the improvement of the corrosion resistance in the electroless Ni-P coated LZ91. The composite coated LZ91 demonstrated better corrosion resistance of mere electroless Ni-P coated LZ91. Furthermore, the corrosion resistance of the composite coated LZ91 was greatly enhanced. The impedance of the composite coated LZ91 was 500 Omega.cm(2), larger than that of the electroless Ni-P coating of 5 Omega.cm(2). The composite coated LZ91 showed better corrosion resistance in the SST exposures in comparison to mere electroless Ni-P coated LZ91. The composite coating indicated that the positive characteristics of a V-Mn conversion coating usefully enhanced the corrosion resistance electroless Ni-P coated LZ91. Moreover, based on the above results, a mechanism for the conversion coating and corrosion resistance was proposed.
Premature Drug Release from Polyethylene Glycol (PEG)-Coated Liposomal Doxorubicin via Formation of the Membrane Attack Complex
(2020-07-28)
Chen, Even
;
Chen, Bing-Mae
;
Su, Yu-Cheng
;
Chang, Yuan-Chih
;
Cheng, Tian-Lu
Anti-polyethylene glycol (PEG) antibodies are present in many healthy individuals as well as in patients receiving polyethylene glycol-functionalized drugs. Antibodies against PEG-coated nanocarriers can accelerate their clearance, but their impact on nanodrug properties including nanocarrier integrity is unclear. Here, we show that anti-PEG IgG and IgM antibodies bind to PEG molecules on the surface of PEG-coated liposomal doxorubicin (Doxil, Doxisome, LC-101, and Lipo-Dox), resulting in complement activation, formation of the membrane attack complex (C51/-9) in the liposomal membrane, and rapid release of encapsulated doxorubicin from the liposomes. Drug release depended on both classical and alternative pathways of complement activation. Doxorubicin release of up to 40% was also observed in rats treated with anti-PEG IgG and PEG-coated liposomal doxorubicin. Our results demonstrate that anti-PEG antibodies can disrupt the membrane integrity of PEG-coated liposomal doxorubicin through activation of complement, which may alter therapeutic efficacy and safety in patients with high levels of pre-existing antibodies against PEG.
Incorporating graphene quantum dots to enhance the photoactivity of CdSe-sensitized TiO2 nanorods for solar hydrogen production
(2020-07-28)
Chang, Yung-Shan
;
Hsieh, Ping-Yen
;
Chang, Tso-Fu Mark
;
Chen, Chun-Yi
;
Sone, Masato
This work demonstrated that the incorporation of graphene quantum dots (GQDs) can greatly improve the photoelectrochemical (PEC) efficiency of CdSe-sensitized TiO2 nanorods (TiO2/CdSe), a TiO2-based visible light-responsive photoelectrode paradigm, for solar hydrogen production. For TiO2/CdSe, the accumulated holes at CdSe may induce photocorrosive oxidation to decompose CdSe, deteriorating the long-term stability of the photoelectrode and degrading the PEC performance. With the introduction of GQDs, the delocalized holes can further transfer from CdSe to the GQDs, which eases the hole accumulation at the CdSe sites, thus retarding photocorrosion. Compared to the binary TiO2/CdSe photoanode, the ternary TiO2/CdSe/GQD photoanode displays higher photocurrent and better photostability toward PEC hydrogen production. This superiority can be attributed to vectorial charge transfer and enhanced reaction kinetics provided by the introduction of GQDs. The findings from this work highlight the importance of the introduction of GQDs as a potential solution to the photocorrosion issue of chalcogenide-sensitized semiconductor photoelectrodes.
Synthesis of hyaluronic acid oligosaccharides with a GlcNAc-GlcA repeating pattern and their binding affinity with CD44
(2020-07-28)
Yeh, Che-Jui
;
Zulueta, Medel Manuel L.
;
Li, Yaw-Kuen
;
Hung, Shang-Cheng
;
應用化學系
Hyaluronic acid (HA) is a ubiquitous glycosaminoglycan in the extracellular matrix and a ligand of CD44, a transmembrane glycoprotein that is important in cell migration. Crystal and NMR studies found a hexasaccharide of the pattern (GlcA-GlcNAc)(3)as the shortest HA that could bind to CD44, but molecular dynamics simulations indicated that a tetrasaccharide of the pattern (GlcNAc-GlcA)(2)is the key structure interacting with CD44. Access to oligomers with such a repeat pattern is crucial in binding studies with CD44. Here we developed a synthetic procedure to afford the HA oligosaccharides with the GlcNAc-GlcA repeating unit and measured the binding interaction between these sugars and human CD44 by isothermal titration calorimetry (ITC). During the chemical synthesis, we successfully generated the beta-glycosidic bond in the absence of neighbouring group participation and overcome the issues in the oxidation step. In addition, ammonia-free dissolving metal reduction for debenzylation and azido reduction has been applied in carbohydrate synthesis for the first time. ITC analysis revealed that the HA tetrasaccharide (GlcNAc-GlcA)(2)could indeed interact and bind to the human CD44.
Correlation among photoluminescence and the electronic and atomic structures of Sr2SiO4:xEu(3+) phosphors: X-ray absorption and emission studies
(2020-07-29)
Zheng, Shi-Yan
;
Chiou, Jau-Wern
;
Li, Yueh-Han
;
Yang, Cheng-Fu
;
Ray, Sekhar Chandra
A series of Eu3+-activated strontium silicate phosphors, Sr2SiO4:xEu(3+) (SSO:xEu(3+), x=1.0, 2.0 and 5.0%), were synthesized by a sol-gel method, and their crystalline structures, photoluminescence (PL) behaviors, electronic/atomic structures and bandgap properties were studied. The correlation among these characteristics was further established. X-ray powder diffraction analysis revealed the formation of mixed orthorhombic alpha'-SSO and monoclinic beta-SSO phases of the SSO:xEu(3+) phosphors. When SSO:xEu(3+) phosphors are excited under ultraviolet (UV) light (lambda=250 nm,similar to 4.96 eV), they emit yellow (similar to 590 nm), orange (similar to 613 nm) and red (similar to 652 and 703 nm) PL bands. These PL emissions typically correspond to 4f-4f electronic transitions that involve the multiple excited D-5(0)-> F-7(J) levels (J=1, 2, 3 and 4) of Eu3+ activators in the host matrix. This mechanism of PL in the SSO:xEu(3+) phosphors is strongly related to the local electronic/atomic structures of the Eu3+-O2- associations and the bandgap of the host lattice, as verified by Sr K-edge and Eu L-3-edge X-ray absorption near-edge structure (XANES)/extended X-ray absorption fine structure, O K-edge XANES and K-alpha X-ray emission spectroscopy. In the synthesis of SSO:xEu(3+) phosphors, interstitial Eu2O3-like structures are observed in the host matrix that act as donors, providing electrons that are nonradiatively transferred from the Eu 5d and/or O 2p-Eu 4f/5d states (mostly the O 2p-Eu 5d states) to the D-5(0) levels, facilitating the recombination of electrons that have transitioned from the D-5(0) level to the F-7(J) level in the bandgap. This mechanism is primarily responsible for the enhancement of PL emissions in the SSO:xEu(3+) phosphors. This PL-related behavior indicates that SSO:xEu(3+) phosphors are good light-conversion phosphor candidates for use in near-UV chips and can be very effective in UV-based light-emitting diodes.
科技部大專生研究獎，陽明獲獎人數創新高
(國立陽明大學, 2020-07-30)
陽明電子報編輯小組
科技部公布「108年度大專學生研究計畫研究創作獎」得獎名單，陽明今年獲獎人數創新高，共有五位同學獲獎，包括醫學系「醫師科學家.
學餐暑假大翻修，九月全新亮相
(國立陽明大學, 2020-07-30)
陽明電子報編輯小組
今年暑假期間，校內有多項工程進行，其中比較大的一項，就是學餐大翻修，包括外牆、內部設施、軟硬體全部進行翻新，預計九月中開...
陽明「偏鄉醫學體驗營」，培養小小部落之星
(國立陽明大學, 2020-07-30)
陽明電子報編輯小組
7月13日這天，陽明迎來一批特別的小小嘉賓。他們是遠從宜蘭山地部落而來，18位南澳國小四、五年級的小朋友。這是他們第一次來到台
醫工學院「創新創業課程」，培育生醫跨領域人才
(國立陽明大學, 2020-07-30)
陽明電子報編輯小組
生物醫學暨工程學院過去六年辦理創新創業人才培育計畫，歷年得獎成果豐碩，共獲18大獎，很榮幸今年續辦教育部「生醫產業與新農業.
2020 亞洲生技大展，陽明產學研醫、研學能量再突破
(國立陽明大學, 2020-07-30)
陽明電子報編輯小組
今年台灣生技年度盛事「2020 亞洲生技大會（BIO Asia-Taiwan）」在疫情中堅定向前，以全新「實體在線」（Online + Live）模式盛大...
美食記憶三疊
(國立陽明大學, 2020-07-30)
張麗君
;
陽明電子報編輯小組
【109年動物中心使用說明會】
(國立陽明大學, 2020-07-30)
陽明電子報編輯小組
講述有關動物中心各區使用方式、動物訂購、代養、轉移和移房等.
【109年職員教育訓練課程2】困境與突破～從貝多芬《命運》聽起
(國立陽明大學, 2020-07-30)
陽明電子報編輯小組
日期：8月4日（二）時間：9:40-12:10 地點：圖資402教.
「愛呀，你好！」社募書活動～用閱讀為孩童築夢
(國立陽明大學, 2020-07-30)
陽明電子報編輯小組
「愛呀，你好！」社成立至今，已邁入第六年。一直以來，本社的宗旨就是藉由陪伴與服務，為榮總兒童癌症病房的病童營造一個有活力的環境，讓他們在醫院的生活不是只有化療，還多了一些與外界接觸的機會，增添生活中特別的經驗。而本社的服務，這六年來也在榮總兒童癌症病房得到很多熱烈的迴響。今年（2020年）二月初，由於武漢肺炎疫情迅速蔓延，在諮詢過醫師後，確定這學期（108學年度下學期）我們無法再進入病房陪伴兒童。這個消息讓我們感到非常的遺憾，因為突如其來的疫情，讓我們失去了進行服務最重要的管道。考量到上述問題，我們決定與「書寶二手書店」合作。
Detection of a Criegee Intermediate with an Unsaturated Hydrocarbon Substituent: Fourier-Transform Microwave Spectroscopy of Methyl Vinyl Ketone Oxide
(2020-07-30)
Endo, Yasuki
;
Witek, Henryk A.
;
Chung, Chen-An
;
Lee, Yuan-Pern
;
交大名義發表
Pure rotational transitions of methyl vinyl ketone oxide, or the so called methyl-vinyl Criegee intermediate, were observed by Fourier-transform microwave spectroscopy. Among the four possible conformers of this species, predicted by theory within an energy window of 3 kcal/mol, only the lowest-energy conformer, the syn-trans form, was detected in a discharged jet of a 1,3-diiode-but-2-ene (either in Z- or E-conformation) and O-2 mixture diluted in Ar. Thirty pure rotational transitions with internal rotation splitting of the methyl top were observed. The observed frequencies were analyzed by the XIAM program, yielding an internal rotation barrier of 702.8(28) cm(-1), which reasonably agrees with a theoretical value of 680 cm(-1) determined with CCSD(T)/cc-pVTZ.