Synthesis and optical properties of the [2.2]paracyclophane-containing π-conjugated polymer with a diacetylene unit

Summary Novel through-spaceπ-conjugated polymer based on poly(p-henyleneethynylene)/poly(p-phenylenebutadiynylene) hybrids containing a [2.2]paracyclophane unit in the main chain was synthesized by copper-catalyzed alkyne coupling reaction. The structure of the polymer was supported by ¹H NMR and IR spectra. The obtained polymer was soluble in common organic solvents such as THF, CH₂C1₂, CHC1₃ and toluene. The number-average of molecular weight of the polymer was estimated to be 63000 by GPC. The polymer emitted a bluish green light in solution and in the solid state. Received:24 September 2002/Revised version: 19 November 2002/Accepted: 19 November 2002 Correspondence to Yoshiki Chujo     

Thermal and dielectric properties of zirconyl phosphate compact

Experimental results are presented on the measurements of thermal expansion (up to 1500°C), thermal conductivity (up to 1000°C), dielectric constant (up to 450 °C) and tan (up to 800 °C) of zirconyl phosphate compacts obtained by sintering at 1600°C. The thermal expansion coefficient of the samples at the temperature below 1100°C was less than 1.7 × 10^–6°C^–1. The samples showed a definite shrinkage at temperatures of 1110 and 1470°C due to the phase transformations. The expansion at 1500°C was less than that at 1100°C probably because of the phase transformation. The thermal conductivity at room temperature was a very small value (0.0046 to 0.0065 cal s^–1 cm°C^–1 cm^–2). The dielectric constant was close to 9. The value of tan° (–0.0001) measured is one of the lowest values for ceramic materials.     

Stromal CCL5 Promotes Breast Cancer Progression by Interacting with CCR3 in Tumor Cells

Chemokines secreted from stromal cells have important roles for interactions with carcinoma cells and regulating tumor progression. C-C motif chemokine ligand (CCL) 5 is expressed in various types of stromal cells and associated with tumor progression, interacting with C-C chemokine receptor (CCR) 1, 3 and 5 expressed in tumor cells. However, the expression on CCL5 and its receptors have so far not been well-examined in human breast carcinoma tissues. We therefore immunolocalized CCL5, as well as CCR1, 3 and 5, in 111 human breast carcinoma tissues and correlated them with clinicopathological characteristics. Stromal CCL5 immunoreactivity was significantly correlated with the aggressive phenotype of breast carcinomas. Importantly, this tendency was observed especially in the CCR3-positive group. Furthermore, the risk of recurrence was significantly higher in the patients with breast carcinomas positive for CCL5 and CCR3 but negative for CCR1 and CCR5, as compared with other patients. In summary, the CCL5-CCR3 axis might contribute to a worse prognosis in breast cancer patients, and these findings will contribute to a better understanding of the significance of the CCL5/CCRs axis in breast carcinoma microenvironment.     

MiR-10a in Pancreatic Juice as a Biomarker for Invasive Intraductal Papillary Mucinous Neoplasm by miRNA Sequencing

New biomarkers are needed to further stratify the risk of malignancy in intraductal papillary mucinous neoplasm (IPMN). Although microRNAs (miRNAs) are expected to be stable biomarkers, they can vary owing to a lack of definite internal controls. To identify universal biomarkers for invasive IPMN, we performed miRNA sequencing using tumor-normal paired samples. A total of 19 resected tissues and 13 pancreatic juice samples from 32 IPMN patients were analyzed for miRNA expression by next-generation sequencing with a two-step normalization of miRNA sequence data. The miRNAs involved in IPMN associated with invasive carcinoma were identified from this tissue analysis and further verified with the pancreatic juice samples. From the tumor-normal paired tissue analysis of the expression levels of 2792 miRNAs, 20 upregulated and 17 downregulated miRNAs were identified. In IPMN associated with invasive carcinoma (INV), miR-10a-5p and miR-221-3p were upregulated and miR-148a-3p was downregulated when compared with noninvasive IPMN. When these findings were further validated with pancreatic juice samples, miR-10a-5p was found to be elevated in INV (p = 0.002). Therefore, three differentially expressed miRNAs were identified in tissues with INV, and the expression of miR-10a-5p was also elevated in pancreatic juice samples with INV. MiR-10a-5p is a promising additional biomarker for invasive IPMN.     

Orientation in uniaxially drawn polystyrene plasticized by CO2 sorption

Uniaxial drawing experiments of the polystyrene films plasticized by a sorption of compressed CO₂ gas at pressures up to about 18 MPa were carried out with strain rates ε of 0.0290 and 0.0079 s^?1. The drawing was performed successfully with draw ratio λ up to 4 at the temperatures of 308.15, 318.15, 328.15, and 338.15 K. The Hermans orientation function f of the drawn samples was determined from the dichroic ratio measured by an infrared spectrophotmeter. While f value increases with increasing ε or λ, it decreases with increasing CO₂ pressure or temperature. © 1995 John Wiley & Sons, Inc.     

Interaction of cation-exchange membrane with polycation I. Poly(N-methyl-4-vinylpyridinium chloride)

We elucidated the effect of the molecular weight of poly(N-methyl-4-vinylpyridinium chloride) (PMVP) on its adsorbed or ion-exchanged amount on the cation-exchange membrane and the preferntial permselectivity of the membrane for sodium ion to calcium ion. The amount of the adsorbed or ion-exchanged PMVP increases with time and then attains to a definite value at a definite concentration. Also, the ultimate value increases with increasing the concentration of PMVP. When the molecular weight of PMVP is 3090, the ratio of the pyridinium groups of PMVP ion-exchanged with the sulfonic acid groups on the membrane surface to the total pyridinium groups of the cohered PMVP is in the range of 70–80%. The relative transport number of calcium ions to sodium ions(P_Na^Ca) decreases with increasing the amount of adsorbed or ion-exchanged PMVP and the numbe rof non-ion-exchanged pyridinium groups of PMVP and the number of non-ion-exchanged pyridinium groups of PMVP on the membrane surface. The smaller the molecular weight of PMVP, the more the adsorbed or ion-exchanged amount and the more preferable the permselectivity for sodium ion.     

Ni-Mo alloying of nickel surface by alternating pulsed electrolysis using molybdenum(VI) baths

Electrochemical Ni-Mo alloying of the surface of a nickel substrate was investigated using alternating pulsed electrolysis in an aqueous solution containing only molybdate ions (MoO₄²⁻) as a metal ion component. In this electrochemical process, the nickel substrate was slightly dissolved during the anodic pulses, providing nickel ions into the solution in the vicinity of the substrate, while Ni and Mo were both electrodeposited on the substrate surface during the subsequent cathodic pulses. Through the optimization of anodic and cathodic conditions independently based on a set of direct-current electrolysis data, amorphous Ni-Mo alloy layers were found to be formed at the surface of the nickel substrate by the alternating pulsed electrolysis using the MoO₄²⁻ solution of pH 3.0-5.0. The conditions for Ni-Mo alloy formation were discussed in terms of the dissolving regime of ionic species in the electrolytes determined by an equilibrium calculation.     

Studies on syntheses and permeabilities of special polymer membranes

Summary The permeabilities of various cellulose ester membranes and cellulose membranes were investigated using pure water and aqueous solution of glycerol as feed. In all membranes, the permeation rate for aqueous solution of glycerol was greater than for pure water. The permeation rates of cellulose ester membranes increased with an increase in number of carbon atoms of the substituent group in cellulose ester.     

Reaction of sodium perborate with a chlorinated cyclic hindered amine (TMP-Cl): I. Quantitative evaluation of active oxygen species in fabric bleaching

The reaction of N-chloro-4-hydroxy-2,2,6,6-tetramethylpiperidine (TMP-Cl) with sodium perborate (PB) was investigated with special reference to the generation of singlet oxygen and the possible application to a new oxidative bleaching process. Generation of the singlet oxygen (¹O₂), the hydroxyl radical (HO·) and superoxide anion radical (O₂·⁻) in the PB/TMP-Cl mixed solution was confirmed by the trapping reagent method. From the results of another experiment, in which the bleaching abilities of each active oxygen species were confirmed, the main active oxygen species contributing to the bleaching of purpurogallin, the skeleton of black tea pigment, in the PB/TMP-Cl system was concluded to be¹O₂.