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131.
We described reversible affinity interactions of antibody molecules at a chemically functionalized electrode surface for a repeatedly renewable affinity-biosensing interface. Underlying biofunctionalizable monolayers were constructed with poly(amidoamine) dendrimers, whose surface chain-end groups were double-functionalized with biotinyl ligand and ferrocenyl groups for biospecific recognition and electron transfer reactions, respectively. Functionalized monolayers on gold electrodes provide platform surfaces for biospecific recognition reaction with monoclonal anti-biotin antibody molecules. Bound antibody molecules were dissociated from the surface via displacement reaction by the addition of free biotin in solution, enabling the affinity surface to be renewed and repeatedly utilized. Tracking of the association/dissociation reaction cycles were performed by registering the bioelectrocatalytic currents at the electrode using glucose oxidase (GOx) as a signal generator and ferrocenyl-tethered dendrimer (Fc-D) as an electron transferring mediator in electrolyte. Shielding of the affinity surface by biospecifically bound antibody molecules caused hindrance in electron transfer, resulting in reduced signal from cyclic voltammetry. By the displacement reaction using free biotin, bound antibody molecules were dissociated from the surface and the bioelectrocatalytic signal was restored. With the affinity surfaces constructed in this work, continuous association/dissociation reactions have been successfully accomplished, providing a possibility of reusable affinity biosensing interface. 相似文献
132.
Jeong Hyun Yeum Byung Chul Ji Chul Joo Lee Ji Youl Lee Sang‐Seob Lee Sam Soo Kim Joon Ho Kim Won Seok Lyoo 《Journal of polymer science. Part A, Polymer chemistry》2002,40(8):1103-1111
To prepare water‐soluble, syndiotacticity‐rich poly(vinyl alcohol) (PVA) microfibrils for various industrial applications, we synthesized syndiotacticity‐rich, low molecular weight PVA by the solution polymerization of vinyl pivalate (VPi) in tetrahydrofuran (THF) at low temperatures with 2,2′‐azobis(2,4‐dimethylvaleronitrile) (ADMVN) as an initiator and successive saponification of poly(vinyl pivalate) (PVPi). Effects of the initiator and monomer concentrations and the polymerization temperature were investigated in terms of the polymerization behaviors and molecular structures of PVPi and the corresponding syndiotacticity‐rich PVA. The polymerization rate of VPi in THF was proportional to the 0.91 power of the ADMVN concentration, indicating the heterogeneous nature of THF polymerization. The low‐temperature solution polymerization of VPi in THF with ADMVN proved to be successful in obtaining water‐soluble PVA with a number‐average degree of polymerization (Pn) of 300–900, a syndiotactic dyad content of 60–63%, and an ultimate conversion of VPi into PVPi of over 75%. Despite the low molecular weight of PVA with Pn = 800, water‐soluble PVA microfibrillar fibers were prepared because of the high level of syndiotacticity. In contrast, for PVA with Pn = 330, shapeless and globular morphologies were observed, indicating that molecular weight has an important role in the in situ fibrillation of syndiotacticity‐rich PVA. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1103–1111, 2002 相似文献
133.
D.H. Kim J.H. Moon D.W. Lee Y.G. Shul 《Journal of Sol-Gel Science and Technology》2003,26(1-3):403-406
The acid catalyzed sol-gel reaction in the mixed binder system, 3-glycidoxypropyltrimethoxysilane (GPTS)/3-aminopropyltriethoxysilane (APTS) was investigated and one step and two step synthesis process were compared. Hydrolysis product was observed using the 1H, 13C NMR and Raman spectra. Especially, based on the Raman spectra, epoxy ring opening was observed, varying the ratio of GPTS to APTS. The two step process made clear sol, while the one step process resulted in a milky suspension. According to the Raman spectra, the epoxy ring opening reaction kinetics proceeded slower in the two step process than one step process. Throughout the two step process, it was possible to apply the binder for the coating of substrate. 相似文献
134.
P-C bond cleavage of α-fluoro-α-phosphonyl malonates using magnesium chloride provides a new synthetic route to α-fluoro malonates. 相似文献
135.
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137.
John D. Roehling Christopher W. Rochester Hyun Wook Ro Peng Wang Jaroslaw Majewski K. Joost Batenburg Ilke Arslan Dean M. Delongchamp Adam J. Moulé 《Journal of Polymer Science.Polymer Physics》2014,52(19):1291-1300
The morphology in mixed bulk‐heterojunction films are compared using three different quantitative measurement techniques. We compare the vertical composition changes using high‐angle annular dark‐field scanning transmission electron microscopy with electron tomography and neutron and x‐ray reflectometry. The three measurement techniques yield qualitatively comparable vertical concentration measurements. The presence of a metal cathode during thermal annealing is observed to alter the fullerene concentration throughout the thickness of the film for all measurements. However, the absolute vertical concentration of fullerene is quantitatively different for the three measurements. The origin of the quantitative measurement differences is discussed. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1291–1300 相似文献
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139.
An optimal hydrophobic ionic liquid was discovered as a solvent for highly enantioselective glyoxylate-ene reactions catalyzed by a chiral bis(oxazoline)–copper complex. The reactivity and stereoselectivity were highly dependent upon the property of the ionic liquids; reactions between olefins and ethyl glyoxylate in [Bmim]SbF6 at ambient temperature provided remarkably enhanced reactivity and stereoselectivity, which greatly exceed those of the corresponding reactions in dichloromethane. Furthermore, the metal–ligand complex was readily recycled up to eight times while exhibiting no significant decrease in reaction efficiency. 相似文献
140.
In this study, a sensitive, simple and reliable method for the quantification of docetaxel in rat plasma was developed and validated using liquid chromatography–tandem mass spectrometry (LC‐MS/MS). The plasma samples were prepared by protein precipitation, and paclitaxel was used as an internal standard (IS). Chromatographic separation was achieved using a Gemini C18 column (2.0 × 150 mm, 5 µm) with a mobile phase consisting of 0.1% formic acid–acetonitrile (30:70, v/v). The precursor–product ion pairs used for multiple reaction monitoring were m/z 808.5 → 527.5 (docetaxel) and m/z 854.2 → 286.5 (IS, paclitaxel). A calibration curve for docetaxel was constructed over the range 1–1000 ng/mL. The developed method was specific, precise and accurate, and no matrix effect was observed. The validated method was applied in a comparative pharmacokinetic study in which two docetaxel formulations, SID530, a new parenteral formulation of docetaxel with hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD), and Taxotere, were administered to rats at a dose of 5 mg/kg. For SID530 and Taxotere, the mean C0 values were 1494 and 1818 ng/mL, respectively, and the AUClast values were 837 and 755 h ng/mL, respectively. These two formulations did not show any statistical differences with regard to the pharmacokinetic parameters, thus establishing that the SID530 and Taxotere products are pharmacokinetically comparable in male rats. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献