Interfacial profiles of miscible poly(4‐trimethylsilylstyrene)/polyisoprene bilayer films

Compositional profiles of bilayer films in the direction normal to the interfaces have been investigated by neutron reflectivity measurements and analyzed with mean field theory. The bilayer films were prepared with poly(4‐trimethylsilylstyrene) (PTMSS) and polyisoprene (PI), which constitute a miscible polymer pair and whose blends show phase separation at the lower critical solution temperature (LCST) by heating. Because we can accurately control the degree of polymerization of component polymers and can adjust the Flory–Huggins interaction parameter, χ, with the temperature, T, according to the relationship χ = 0.027–9.5/T, the phase behavior and the interfacial structure of PTMSS and PI are predictable by mean field theory. When the bilayer films of PTMSS and PI were set at 90 °C, which is a temperature below the LCST, diffusion at the interface was observed, and the original interface disappeared in several hours; this supports the idea that the polymer pair is miscible. No clear interfaces were identified below the LCST, whereas broad interfaces, compared with that of the strong segregation pairs, were observed above the LCST. The compositions of each layer are consistent with that of the coexisting phase in the polymer blends, and the interfacial widths agree well with the theoretical prediction considering the effect of capillary waves. In addition, all annealed films have a thin surface layer of PTMSS corresponding to surface segregation induced by the lower surface energy of PTMSS (with respect to that of PI). Thus, the interfacial profiles of PTMSS/PI bilayer films have been totally prospected in the framework of mean field theory. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1486–1494, 2005     

All-Optical Holographic Label Processing for Photonic Packet Switching

A holographic label processor for photonic packet switching is proposed. We observe the process of time-to-space conversion for an optical code consisting of 2 ps pulses at a wavelength of 1.55 $mUm with 100 km fiber transmission. Label recognition using an angular multiplexed spectral hologram (AMSH) as a label bank is experimentally demonstrated. We also investigate the AMSH by CGH and confirm its feasibility in computer simulations.     

Sequential injection analysis with chemiluminescence detection for the antioxidative activity against singlet oxygen.

A sequential injection analysis (SIA) with chemiluminescence (CL) detection was developed for the measurement of antioxidative activity against singlet oxygen ((1)O2). Lactoperoxidase-hydrogen peroxide-bromide ion system was used for the generation of (1)O2. When a 100 mM sodium acetate buffer (pH 4.5) was used as a carrier solution, the SIA-CL system could be optimized with respect to the flow-rate of the carrier, concentration of reagents and their aspiration order. The antioxidative activity was expressed as an attenuation of luminol CL due to the quenching of (1)O2 by an antioxidant. The relative standard deviations of antioxidative activity (n=3) against (1)O2 for within- and between-day analyses were < or = 1.6% (20 microM Trolox). The system was successfully applied to the assay of antioxidative activities of various antioxidants including vitamin supplements at a rate of 10 samples within 15 min. The proposed SIA-CL system was rapid and reproducible with minimum consumption of the sample and of reagents, and thus was useful for the screening of compounds possessing antioxidative activity against (1)O2.     

Fluorescence chemical sensor based on water‐soluble poly(p‐phenylene ethynylene)–graphene oxide composite for Cu2+

A chemical sensor for metal ions was fabricated based on a water‐soluble conjugated polymer–graphene oxide (GO) composite. Water‐soluble poly(p‐phenylene ethynylene) (PPE) with sulfonic acid side chain groups was used to prepare a very stable water‐soluble PPE–GO composite with strong π–π interactions in water. The relationship between the optical properties and metal ion sensing capability of the PPE–GO composite in aqueous solution was investigated. Addition of metal ions enhanced the fluorescence intensity of the composite, and, in particular, the composite enabled the fluorescence detection of Cu²⁺ in aqueous solutions with high selectivity and sensitivity. Therefore, this conjugated polymer–GO composite sensor system was found to be an effective turn‐on type chemical sensor for metal ions. Copyright © 2015 John Wiley & Sons, Ltd.     

Determination of human serum semicarbazide-sensitive amine oxidase activity via flow injection analysis with fluorescence detection after online derivatization of the enzymatically produced benzaldehyde with 1,2-diaminoanthraquinone

A fast, simple, and sensitive flow injection analysis method was developed for the measurement of semicarbazide-sensitive amine oxidase (SSAO) activity in human serum. Benzaldehyde, generated by the action of SSAO after incubation of serum with benzylamine, was derivatized with a novel aromatic aldehyde-specific reagent (1,2-diaminoanthraquinone) and the fluorescent product was measured by fluorescence detection at excitation and emission wavelengths of 390 and 570 nm, respectively. Serum SSAO activity was defined as benzaldehyde (nmol) formed per milliliter serum per hour. The method was linear over SSAO activity of 0.2–150.0 nmol mL⁻¹ h⁻¹ with a detection limit of 0.06 nmol mL⁻¹ h⁻¹. The %RSD of intra-day and inter-day precision did not exceed 9.4% and the accuracy ranged from −6.5 to −0.6%. The method was applied for the determination of the serum SSAO activity in healthy controls (C, n = 24) and diabetes mellitus patients (DM, n = 18). It was demonstrated that the activity (mean ± SE) of SSAO in diabetics sera was significantly higher than that in healthy subjects’ ones (DM; 73.3 ± 1.8 nmol mL⁻¹ h⁻¹vs C; 58.9 ± 2.2 nmol mL⁻¹ h⁻¹, P < 0.01).     

Air‐Stable Cationic Gold(I) Catalyst Featuring a Z‐Type Ligand: Promoting Enyne Cyclizations

An air‐stable cationic Au^I complex featuring a Z‐type ligand (boron atom) as a σ‐acceptor was developed for elucidating the effect of B on catalytic reactions. An enyne cyclization in the presence of either [Au→B]⁺ or [Au]⁺ showed that [Au→B]⁺ promotes the reactivity, which enabled the effective construction of not only five‐ and six‐membered rings, but also seven‐membered rings.     

Asymmetric flow catalysis: Mix-and-go solid-phase Nd/Na catalyst for expeditious enantioselective access to a key intermediate of AZD7594

An anti-selective catalytic asymmetric nitroaldol reaction was implemented in a continuous-flow reaction platform for the synthesis of a key intermediate of a drug candidate. The requisite solid-phase catalyst was readily prepared by mixing an amide-based chiral ligand and inexpensive inorganic salts, NdCl₃?6H₂O and NaO^tBu, without covalent bond linkages. The flow system was operated with 2-Me-THF as the eluent for ca. 400 h to provide a crude nitroaldol adduct in a highly stereoselective manner with no work-up procedure, reaching turnover number over 1600. Facile reduction of the nitro group of the product afforded a key intermediate of AZD7594, a therapeutic candidate for asthma and chronic obstructive pulmonary disease.     

Spatial mode exchange technique using volume holograms with a random optical diffuser for reduction of crosstalk

Optical Review - In mode-division multiplexing systems, the transmission quality is restricted by the differential mode delay (DMD). We previously proposed a spatial mode exchange technique using...     

Enantioselective reductive multicomponent coupling reactions between isatins and aldehydes

A metal-free stereoselective reductive coupling reaction between isatins and aldehydes is reported. The reaction relies on commercial diethyl phosphite (∼€70 kg^–1) as the stoichiometric reductant. Base-catalyzed Pudovik addition and phosphonate/phosphate rearrangement achieved polarity inversion on the isatin, and the derived carbanions were trapped by aldehydes with subsequent dialkoxyphosphinyl migration. Chiral iminophosphoranes were used as basic catalysts to achieve high diastereo- and enantioselectivities with excellent yields.     

Ring‐opening polymerization of lipoic acid and characterization of the polymer

Thermal polymerization of DL ‐α‐lipoic acid (LPA) in bulk without any initiator proceeded easily above the melting point of LPA. The molecular weight polymer determined by GPC was high. From the ¹H NMR spectra of polymers, poly(LPA) obtained from polymerization of high purity LPA was to consist of cyclic structures, which was confirmed by ESI‐MS. Interlocked polymer consisting of poly(LPA) and dibenzo‐30‐crown‐10 entangled with each other was synthesized by the polymerization of LPA in the presence of dibenzo‐30‐crown‐10. From the DSC analysis of the polymers, glass transition temperature was estimated to be about ?11 °C, but melting point was not observed, indicating that poly(LPA) is an amorphous polymer. By photodecomposition of poly(LPA), M_n was rapidly decreased at the early stage of the decomposition. After that, the M_n of the polymer kept and then was almost constant even for a prolonged reaction time. On the basis of the results, it would be presumed that poly (LPA) obtained form polymerization of high purity LPA includes an interlocked structure. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010