Hyperbranched-linear poly(ether sulfone) blend films for proton exchange membranes

Hyperbranched poly(ether sulfone) polymers having sulfonyl chloride end-groups is blended at up to 30 w% with linear poly(ether ether ether sulfone)s and a two-phase system is generated via spinodal decomposition upon drying from a DMAc solution. Conversion of the end-groups from sulfonyl chloride to sulfonic acid is accomplished using 16 M H₂SO₄ that is also believed to introduce additional sulfonic acid groups at the interface of the linear polymer. The blend films before and after conversion to sulfonic acid have similar tensile strengths as films composed of solely linear polymer (yield stress >40 MPa and Young's modulus >3 GPa m). These films are designed to test the viability of hyperbranched polymers as fuel cell membranes. Proton conductivities of up to 0.03 S cm⁻¹ are observed at 80 °C and 90% R.H indicating a good potential for use of hyperbranched polymers as a proton conduction material.     

Effects of vasopressin and involvement of receptor subtypes in the rat central amygdaloid nucleus in vitro

Effects of arginine-vasopressin (AVP) on neurons in the central amygdaloid nucleus (ACe) were investigated with rat brain slice preparations using extracellular recording methods. Of 160 ACe neurons tested, 70 cells (44%) were excited and 9 cells (6%) were inhibited by bath application of AVP at 3 x 10(-7) M. The excitatory effects of AVP were dose-dependent and the threshold concentration was approximately 10(-10) to 10(-9) M. The excitatory effects of AVP persisted under blockade of synaptic transmission by perfusing with Ca2+-free and high-Mg2+ medium, whereas the inhibitory effects were abolished by synaptic blockade. AVP-induced effects were mimicked by a V1-receptor agonist and completely blocked by a selective V1-antagonist. V2-agonist produced no effects on ACe neurons and V2-antagonist had no effect on AVP-induced excitation. These results showed that the excitatory effect of AVP on ACe neurons was produced by a direct action through the V1-receptors, whereas the inhibitory response of ACe neurons to AVP seemed to be produced by an indirect action. The results of this study suggest that AVP is involved in the amygdala-relevant functions as a neurotransmitter or a neuromodulator.     

Double liquid crystalline side-chain type block copolymers for hierarchically ordered nanostructures: Synthesis and morphologies in the bulk and thin film

Well-defined double liquid crystalline side-chain type block copolymers (DLC-BCPs) were synthesized by nitroxide-mediated living free radical polymerization (NMP) of two different types of styrene monomers containing liquid crystalline moieties. The molecular weights and compositions were controlled by changing the polymerization time and/or the feed amount of the monomers. The bulk morphologies were studied using wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). DLC-BCPs were favored to form microphase-separated lamellar structures over a wide range of volume fractions. By controlling the annealing conditions, further higher-ordered hierarchical nanostructures were obtained with a long-range alignment, in which the semi-crystalline side-chains were oriented parallel to the interface of microphase-separated lamellar structure. Thin film morphology was investigated using atomic force micrography (AFM). The formation of lamellar nanostructure with a long-range alignment vertically oriented to the silicon wafer substrate was achieved by simple thermal annealing.     

STM-64 linearly repeatered optical transmission experiment usingforward error correcting codes

STM-64 (10 Gbit/s) nonregenerative transmission experiments using forward error correcting codes have been conducted for the first time. Bit errors caused by dispersion in the transmission line and optical noise of Er-doped fibre amplifiers were successfully corrected by using (18880, 18865) and (2370, 2358) shortened Hamming codes     

Integrated biosensor employing a surface photovoltage technique

A monolithically integrated biosensor is constructed using a surface photovoltage (SPV) technique combined with a new patterning method for multiple enzyme integration. The SPV method provides a contactless sensing system leading to patterning flexibility. Photolithographical patterning methods using a water-soluble photocrosslinkable polymer (copolymer of dimethylacrylamide and cinnamoyloxyethylmethacrylate) are applied to immobilize the enzyme on a semiconductor surface. For bonding the enzyme membrane to the semiconductor surface, photoreactive poly-(meta azide styrene) is used, which bonds covalently with both the enzyme membrane and substrate. A pen-printing method has also been proposed for the patterning of enzyme films, which provides a simple method suitable for mass production.     

A novel mode-splitting detection scheme in 43-Gb/s CS- and DCS-RZ signal transmission

Sophistication of the transmission format for 40-Gb/s/ch WDM networks is indispensable. In long-haul transmission applications, the selection of transmission format should be a principal issue. Recently, we have proposed several transmission formats including carrier-suppressed return-to-zero (CS-RZ) and duo-binary-carrier-suppressed (DCS-RZ), in so doing addressing the issue of superior performance versus fiber nonlinearity and spectral efficiency. The special spectrum structure of these formats enables a novel mode-splitting detection scheme. The scheme realizes a variety of applications in 40-Gb/s/ch transmission; including expansion of dispersion tolerance, automatic dispersion compensation, and BER improvement. We achieved 1.6 times. expansion of dispersion tolerance of 43-Gb/s DCS-RZ signals by introducing mode-splitting in the receiver. By applying the mode-splitting scheme for CS-RZ signals, we also demonstrated precise chromatic dispersion measurement with its sign detection without the need for any dithering operation and its application to automatic dispersion compensation at 43-Gb/s CS-RZ transmission.     

Fully transparent multiplexing and transport of 10 GbE-LANPHY signals for 44.6 Gbit/s-based RZ-DQPSK WDM transmission

Transparent 10 GbE-LANPHY transport for 44.6 Gbit/s RZ-DQPSK WDM transmission is demonstrated for the first time. A single-chip 43/44 Gbit/s OTN framer LSI that supports fully transparent STM-64/10 GbE multiplexing and DQPSK precoding is adopted.     

Cs-leaching behavior of Cs-titanosilicate in NaCl solution

Cs-titanosilicate, which is a pollucite-related phase, was synthesized and the Cs-leaching behavior of Cs-titanosilicate was evaluated in a NaCl aqueous solution and ion-exchanged water. CsNO₃, TiO₂ and SiO₂ powders were mixed in ethanol by ball-milling and then the mixed powder was heated at temperatures of 600 to 900 °C under atmospheric and reduced pressures of air. Under reduced pressure, the Cs-titanosilicate phase was crystallized at 700 °C, which was lower than that under atmospheric pressure because CsNO₃ decomposition was promoted under reduced pressure. The Cs-leaching ratio of the Cs-titanosilicate in a NaCl aqueous solution is higher than that in ion-exchanged water. On the other hand, the Cs-leaching ratio of the Cs-titanosilicate synthesized under the reduced pressure was lower than that under atmospheric pressure. It was considered that the lower negative zeta potential of the Cs-titanosilicate synthesized under the reduced pressure diminished the amount of Na⁺ ion adsorbed on the particles surface of the Cs-titanosilicate, which resulted in the suppression of Cs-leaching.