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31.
We fabricated a Bi-2212/Ag double stacked pancake coil of 13 mmØ) in inner bore and of 46.5 mmØ in outer diameter, by using Bi-2212/Ag tapes prepared by the combination of continuous dip-coating process and melt-solidification technique. This small superconducting magnet was used as an insert magnet of a conventional superconducting magnet system and tested at saturated superfluid helium temperature (~ 1.8K) in various bias fields. The generated field of Bi2212/Ag coil was 0.9 T, with Ic of 310 A(criterion 10-13Ω·m), in the bias field of 20.9 T. Thus, this superconducting magnet system achieved generation of magnetic field of 21.8 T in the full superconducting state.  相似文献   
32.
The rheological behavior and morphology of polystyrene/carbon nanofiber (PS/CNF) composites in their melt phase have been characterized through experimental measurements. Viscosity measurements of the PS/CNF composites in the linear viscoelastic regime show the ratio of the transient extensional viscosity to the transient shear viscosity to be greater than three, the Trouton ratio. This behavior is due to differences in the flow‐induced orientation of CNFs in shear and extensional flow. The orientation development of the CNFs in shear and extensional flow was analyzed through a method utilizing transmission electron microscopy and was used to explain observed rheological phenomena. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   
33.
In this study, in order to explore the possibility of biosynthesizing a novel polyhydroxyalkanoate (PHA), copolymerization of 3-hydroxy-2-methylbutyrate (3H2MB) as the α-position methylated monomer and 3-hydroxyhexanoate (3HHx) as the medium-chain-length monomer was performed to obtain P(3H2MB-co-3HHx). The β-oxidation-deficient Escherichia coli LSBJ, harboring the PHA biosynthetic operon from Aeromonas caviae and the propionyl-CoA transferase gene (pct) from Megasphaera elsdenii, was cultured with feeding tiglic and hexanoic acids as the precursors for 3H2MB and 3HHx, respectively. It was observed that pct expression was highly effective to enhance the incorporation of 3H2MB into PHA. The biosynthesized PHA was composed of 3H2MB and 3HHx units only, and the 3H2MB fraction varied in the range of 36–60 mol% depending on the culture conditions. These PHAs exhibited glass transition temperatures between ?11 to ?17 °C; moreover, no melting peak was observed during analysis using differential scanning calorimetry. This study demonstrated the biosynthesis of a hitherto unreported PHA by engineering metabolic pathway in E. coli.  相似文献   
34.
Unique deterioration with a striped pattern caused by thermal heating is reported for injection molding comprising polypropylene/ethylene–α‐olefin rubber blends. This stripe is due to the formation of glossy and cloudy parts in alternation approximately perpendicular to the flow direction of the molten resin. On the surface of the cloudy part, a number of micro‐objects appear. They have a dome shape about 10 μm in diameter and 2 μm height. Some experimental evidence indicates that the objects are composed of the rubber contained in the blends. On the other hand, only a few objects appear in the glossy region after heating. This is the reason that the stripe with the micro‐objects (migrating rubber to the surface) is examined in terms of a higher order structure of injection molding with laser scanning microscopy, wide‐angle X‐ray scattering, and microhardness (Martens hardness). Consequently, we have concluded that this thermally deteriorated stripe depends on periodic changes in the crystallinity along the flow direction. The evidence indicates that a snakelike flow occurs during the injection process of the molding. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008  相似文献   
35.
Arylamine polymers were prepared via the facile one‐step addition condensation of N,N′‐diphenyl‐N,N′‐bis(4‐methylphenyl)‐1,4‐phenylenediamine and 4‐methoxytriphenylamine with paraldehyde. The polymers were highly soluble in common organic solvents. The non‐conjugated arylamine polymer structure was characterized and found to form tough, homogeneous, amorphous layers with a glass transition temperature above 200 °C on a substrate by a simple spin‐coating process. The polymer layers exhibited a hole mobility of the order of 10?5 cm2 V?1 s?1, which was comparable with those of previously reported arylamine polymers, and a highest occupied molecular orbital level of ?5.38 eV appropriate for the hole‐transporting layer of perovskite solar cells. The perovskite cells fabricated with the polymers gave a photovoltaic conversion efficiency of 16.0%. © 2018 Society of Chemical Industry  相似文献   
36.
Abstract

Poly(amidoamine)s (PAMAMs) incorporated into a cross-linked poly(ethylene glycol) exhibited excellent CO2 separation properties over H2. However, the CO2 permeability should be increased for practical applications. Monoethanolamine (MEA) used as a CO2 determining agent in the current CO2 capture technology at demonstration scale was readily immobilized in poly(vinyl alcohol) (PVA) matrix by solvent casting of aqueous mixture of PVA and the amine. The resulting polymeric membranes can be self-standing with the thickness above 3 μm and the amine fraction less than 80 wt%. The gas permeation properties were examined at 40 °C and under 80% relative humidity. The CO2 separation performance increased with increase of the amine content in the polymeric membranes. When the amine fraction was 80 wt%, the CO2 permeability coefficient of MEA containing membrane was 604 barrer with CO2 selectivity of 58.5 over H2, which was much higher than the PAMAM membrane (83.7 barrer and 51.8, respectively) under the same operation conditions. On the other hand, ethylamine (EA) was also incorporated into PVA matrix to form a thin membrane. However, the resulting polymeric membranes exhibited slight CO2-selective gas permeation properties. The hydroxyl group of MEA was crucial for high CO2 separation performance.  相似文献   
37.
A coupled-mode formulation for an NRD-guide coupler is presented using the singular perturbation technique. The first-order and second-order perturbations are taken into account in the analysis and the coupled-mode equations based on the eigenmodes of each waveguide in isolation are derived. The propagation constants obtained by these equations are compared with those by the exact theory, conventional coupled-mode theory, and improved coupled-mode theory. The numerical results of present formulation are in good agreement with the exact theory and superior to those of the other formulations.  相似文献   
38.
Compelling evidence suggests that pyroglutamate-modified Aβ (pGlu3-Aβ; AβN3pG) peptides play a pivotal role in the development and progression of Alzheimer’s disease (AD). Approaches targeting pGlu3-Aβ by glutaminyl cyclase (QC) inhibition (Varoglutamstat) or monoclonal antibodies (Donanemab) are currently in clinical development. Here, we aimed at an assessment of combination therapy of Varoglutamstat (PQ912) and a pGlu3-Aβ-specific antibody (m6) in transgenic mice. Whereas the single treatments at subtherapeutic doses show moderate (16–41%) but statistically insignificant reduction of Aβ42 and pGlu-Aβ42 in mice brain, the combination of both treatments resulted in significant reductions of Aβ by 45–65%. Evaluation of these data using the Bliss independence model revealed a combination index of ≈1, which is indicative for an additive effect of the compounds. The data are interpreted in terms of different pathways, in which the two drugs act. While PQ912 prevents the formation of pGlu3-Aβ in different compartments, the antibody is able to clear existing pGlu3-Aβ deposits. The results suggest that combination of the small molecule Varoglutamstat and a pE3Aβ-directed monoclonal antibody may allow a reduction of the individual compound doses while maintaining the therapeutic effect.  相似文献   
39.
Formation of foam cells as a result of excess lipid accumulation by macrophages is a pathological hallmark of atherosclerosis. Fingolimod (FTY720) is an immunosuppressive agent used in clinical settings for the treatment of multiple sclerosis and has been reported to inhibit atherosclerotic plaque development. However, little is known about the effect of FTY720 on lipid accumulation leading to foam cell formation. In this study, we investigated the effects of FTY720 on lipid accumulation in murine macrophages. FTY720 treatment reduced lipid droplet formation and increased the expression of ATP-binding cassette transporter A1 (ABCA1) in J774 mouse macrophages. FTY720 also enhanced the expression of liver X receptor (LXR) target genes such as FASN, APOE, and ABCG1. In addition, FTY720-induced upregulation of ABCA1 was abolished by knockdown of sphingosine kinase 2 (SphK2) expression. Furthermore, we found that FTY720 treatment induced histone H3 lysine 9 (H3K9) acetylation, which was lost in SphK2-knockdown cells. Taken together, FTY720 induces ABCA1 expression through SphK2-mediated acetylation of H3K9 and suppresses lipid accumulation in macrophages, which provides novel insights into the mechanisms of action of FTY720 on atherosclerosis.  相似文献   
40.
Polyelectrolyte polyacrylic acid (PAA), used in the chemical modification of titanium dioxide (TiO(2)) nanoparticles, allows TiO(2) nanoparticles to remain in suspension at neutral pH. The anti-17beta-estradiol (E2) antibody was immobilized on PAA-modified TiO(2) (PAA-TiO(2)) nanoparticles via covalent bonding between the carboxylic acid of PAA and the amino group of the antibody. The anti-E2-antibody-immobilized TiO(2) (E2Ab-PAA-TiO(2)) nanoparticles can form a suspension at neutral pH, with a particle size of less than 100 nm. The E2-PAA-TiO(2) nanoparticles caused the photocatalytic degradation of a typical TiO(2) substrate, methylene blue. The anti-E2 antibody immobilized on the TiO(2) surface recognized and bound E2 in the solution, thereby improving the efficiency of E2 degradation compared with that of PAA-TiO(2) nanoparticles. These results demonstrate that the E2Ab-PAA-TiO(2) nanoparticles developed in this study can be used in water treatment technology. Furthermore, this strategy of immobilizing proteins on nanoscale TiO(2) particles creates new applications not only in the treatment of environmental waste, but also in medical and public sanitation processes.  相似文献   
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