Browsing by Author "Lin, Ya-Shiuan"

Now showing 1 - 5 of 5

Fullerene Derivatives Incorporating Phosphoramidous Ylide and Phosphoramidate: Synthesis and Property
(2009-07-03)
Chen, Sheng-Yuan
;
Cheng, Rai-Long
;
Tseng, Cheng-Kuo
;
Lin, Ya-Shiuan
;
Lai, Li-Hsiang
The reaction of dimethyl acetylenedicarboxylate (DMAD) with C(60) in the presence of hexamethylphosphorous triamide (HMPT) or hexaethylphosphorus triamide (HEPT) results in fullerene derivatives incorporating HMPT or HEPT ylides. The ylide derivatives exhibit unusual electronic absorptions in the visible region (435-660 nm), likely due to the presence of the ylide moiety. Electrochemical studies revealed that the first reductive potential of these compounds was more negative relative to those of both C(60) (Delta E = 130 mV) and a simple Bingel adduct (Delta E = 90 mV). A phosphoramidate side product, which resulted from the addition of HMPT or HEPT to C(60) followed by hydrolysis, exhibited a featureless absorption spectrum in the visible region and a more negative first reductive potential (Delta E = 70 mV) relative to that of C(60).
Heavy chain of cytoplasmic dynein is a major component of the postsynaptic density fraction
(2006-08-01)
Cheng, Huei-Hsuan
;
Liu, Szu-Heng
;
Lee, Flui-Chen
;
Lin, Ya-Shiuan
;
Huang, Zu-Han
A protein with an apparent molecular size of 490 kDa was found in the postsynaptic density (PSD) fraction isolated from porcine cerebral cortices and rat forebrains, and this 490 kDa protein accounted for similar to 3% of the total protein of these samples. Matrix-assisted laser desorption ionization-time of flight mass spectrometric and Western blotting analyses consistently indicated that this 490 kDa protein consisted primarily of the heavy chain of cytoplasmic dynein (cDHC). Immunocytochemical analyses showed that cDHC was found in 92% and 89% of the phalloidin-positive protrusions that were themselves associated with discrete clusters of synaptophysin, a presynaptic terminal marker, and PSD-95, a postsynaptic marker, on neuronal processes, respectively. Quantitative Western blotting analyses of various subcellular fractions isolated from porcine cerebral cortices and rat forebrains further showed that not only the heavy but also the intermediate chains of dynein are enriched in the PSD fraction. Cytoplasmic dynein is a microtubule-associated motor protein complex that drives the movement of various cargos toward the minus ends of microtubules and plays many other diverse functions in the cell. Our results that cDHC is a major component of the PSD fraction, that both dynein heavy and intermediate chains are enriched in the PSD fraction and that cDHC is present in dendritic spines raise the possibilities that cytoplasmic dynein may play structural and functional roles in the postsynaptic terminal. (c) 2006 Wiley-Liss, Inc.
Metal oxide-assisted laser desorption/ionization mass spectrometry
(2006-07-06)
Chen, Yu-Chie
;
Chen, Cheng-Tai
;
Lin, Ya-Shiuan
The invention provides a simple, rapid and cost-effective metal oxide-assisted laser desorption/ionization mass spectrometry (MOALDI MS) without the addition of light-absorbing organic-matrix, comprising the use of (a) an inorganic metal oxide with light absorbing capability as an assisting material to render desorption/ionization of samples in laser desorption/ionization mass spectrometry and (b) a citric acid buffer as the proton source for enhancing the iorization efficiency for analytes. Metal oxide assisting materials is not only restricted to the uses of films. Metal oxide nanoparticles are also suitable to be used as the assisting materials. Low matrix background, stable surface feature, homogeneous sample deposition, and wide detectable mass range are the merits of MOALDI MS.
Nitrilotriacetic acid-coated magnetic nanoparticles as affinity probes for enrichment of histidine-tagged proteins and phosphorylated peptides
(2007-10-01)
Li, Yi-Cheng
;
Lin, Ya-Shiuan
;
Tsai, Pei-Jane
;
Chen, Cheng-Tai
;
Chen, Wei-Yu
We herein demonstrate superparamagnetic Fe3O4 nanoparticles coated with nitrilotriacetic acid derivative (NTA) that can bind with different immobilized metal ions are capable of probing diverse target species. Immobilized Ni(II) on the surfaces of the NTA-magnetic nanoparticles have the capability of selectively trapping histidine (His)tagged proteins such as a mutated streptopain tagged with 6x His, i.e., C192S (MW similar to 42 kDa), from cell lysates. Enrichment was achieved by vigorously mixing the sample solution and the nanoparticles by pipetting in and out of a sample vial for only 30 s. After enrichment, the probe-target species could be readily isolated by magnetic separation. We also characterized the proteins enriched on the affinity probes using on-probe tryptic digestion under microwave irradiation for only 2 min, followed by matrix-assisted laser desorption/ionization mass spectrometry analysis. Using this enrichment and tryptic digestion, the target species can be rapidly enriched and characterized, reducing the time required for carrying out the complete analysis to less than 10 min. Furthermore, when either Zr(IV) or Ga (III) ions are immobilized on the surfaces of the NTA-magnetic nanoparticles, the nanoparticles have the capability of selectively enriching phosphorylated peptides from tryptic digests of alpha-, beta-caseins, and diluted milk. The detection limit for the tryptic digests of alpha- and,beta-caseins is similar to 50 finol.
The effect of the morphology of nanocrystalline CeO2 on ethanol reforming
(2007-06-25)
Hsiao, Wei-In
;
Lin, Ya-Shiuan
;
Chen, Yu-Chie
;
Lee, Chi-Shen
;
應用化學系
CeO2 nanocrystals of cubic and rod shape have been synthesized under hydrothermal conditions on controlling the pH, temperature and duration of reaction. High-resolution transmission electron microscopy indicates that exposed crystal planes are {110} and {100} for rods but {100} for cubes. These nanocrystals have been used in the preparation of a Rh/CeO2 catalyst on an Al2O3 support to test the catalytic activity for ethanol reforming. These catalysts as prepared show good H-2 selectivity compared to catalysts with irregular CeO2 nanoparticles. The {100}/{110}-dominant surface structures play a crucial role in enhancing ethanol reforming; this reaction is important for fuel-cell applications. (c) 2007 Elsevier B.V. All rights reserved.