53 research outputs found

    Soluble Alkyl Substituted Poly(3,4-Propylenedioxyselenophene)s: A New Platform For Optoelectronic Materials

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    Optical and electrochemical properties of regiosymmetric and soluble alkylenedioxyselenophene-based electrochromic polymers, namely poly(3,3-dibutyl-3,4-dihydro-2H-seleno pheno [3,4-b][1,4]dioxephine) (PProDOS-C(4)), poly(3,3-dihexyl-3,4-dihydro-2H-selenopheno[3,4-b][1,4]dioxephine) (PProDOS-C(6)), and poly(3,3-didecyl-3,4-dihydro-2H-selenopheno[3,4-b][1,4]dioxephine) (PProDOS-C(10)), are highlighted. It is noted that these unique polymers have low bandgaps (1.57-1.65 eV), and they are exceptionally stable under ambient atmospheric conditions. Polymer films retained 82-97% of their electroactivity after 5000 cycles. The percent transmittance of PProDOS-C(n) (n = 4, 6, 10) films found to be between 55 and 59%. Furthermore, these novel soluble PPro-DOS-C(n) polymers showed electrochromic behavior: a color change form pure blue to highly transparent state in a low switching time (1.0 s) during oxidation with high coloration efficiencies (328-864 cm(2) C(-1)) when compared to their thiophene analogues. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 4398-4405, 201

    Expanding the Realm of Soluble Narrow Band Gap Polymers with a Benzobisthiadiazole Derivative

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    A donor–acceptor–donor based soluble and narrow band gap π-conjugated electrochromic polymer, poly­(4,8-bis­(3,3-dihexyl-3,4-dihydro-2<i>H</i>-thieno­[3,4-<i>b</i>]­[1,4]­dioxepin-5-yl)­benzo­[1,2-<i>c</i>;4,5-<i>c</i>′]­bis­[1,2,5]­thiadiazole) (<b>P1</b>), was electrochemically (<b>P1-E</b>) and chemically (<b>P1-C</b>) synthesized. Cyclic voltammetry and UV–vis–NIR absorption measurements showed that <b>P1</b> has a low band gap ranging from 0.59 to 1.1 eV, depending on the band gap determination and synthesis (chemical or electrochemical) methods. <b>P1</b> demonstrated an ambipolar electrochemical behavior. The color of the polymer was gray in its neutral state and switched to green (first oxidation state) and blue (second oxidation state) upon oxidation and to brown upon reduction

    The effects of pirfenidone on T helper cells in prevention of intraperitoneal adhesions

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    Abdominal surgery is linked with peritoneal adhesions. We investigated that the anti-fibrotic agent pirfenidone (PFD) has immune modulating activities and evaluated its effects on the function of T helper type 1 (Th1), Th2 and T regulatory (Treg) cells, which may play important roles in peritoneal adhesions. Eighteen female Wistar rats underwent right-sided parietal peritoneal and right uterine horn adhesion model. Rats were randomized into 3 groups as group 1 (control) (closure of midline abdominal incision without any agent administrations), group 2 (closure of incision after intraperitoneal administration of PFD) and group 3 (closure of incision and only oral administration of PFD for 14 days). Relaparotomy was performed 14 days after the first surgery. Effect of PFD on adhesion formation was assessed on Th1, Th2 and Treg cells counts using Anti-T-bet, Anti-GATA-3 Anti-FOXP3 antibodies respectively. Th1 counts were moderate in the control group, and didn't show a significant difference between all groups. Th2 cell counts were very high in the control group, but both intraperitoneal and oral administration of PFD resulted in a significant reduction in Th2 cell counts. Treg cell counts were low in number in the control group. In the intraperitoneal administration of PFD group, Treg cell counts were significantly lower than control group. There was no difference of the Treg cells between control groups and the oral administration of PFD group. PFD has prevention effect on intraperitoneal adhesions. This prevention effect seems to be related with the reduction in the numbers of Th2 and Treg cells

    A neutral state yellow to navy polymer electrochrome with pyrene scaffold

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    A new pyrene based soluble polymer, namely poly(3,3-didecyl-6-(1-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4] dioxepin-6-yl) pyren-6-yl)-3,4-dihydro-2H-thieno[3,4-b][1,4] dioxepine), P5, which is synthesized by both chemical and electrochemical methods, is highlighted. The polymer shows both electrochromic and fluorescent properties (the emission of yellow (545 nm) and yellowish green light (524 nm) in solid state and in THF solution, respectively). It is noteworthy that P5 has a specific optical band gap (2.2 eV) to reflect the yellow color in the neutral state. Furthermore, the optical and electrochemical features of the polymer were investigated. (C) 2011 Elsevier B. V. All rights reserved

    A blue to highly transmissive soluble electrochromic polymer based on poly(3,4-propylenedioxyselenophene) with a high stability and coloration efficiency

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    The optical and electrochemical properties of a regioregular and soluble alkylenedioxyselenophene-based electrochromic polymer, namely poly(3,3-didecyl-3,4-dihydro-2H-selenopheno[3,4-b][1,4] dioxepine (PProDOS-C-10), which is synthesized by electrochemical polymerization, are highlighted. It is noted that this unique polymer has a low band gap (1.58 eV) and is exceptionally stable under ambient atmospheric conditions. Polymer films retain 97% of their electroactivity after 40 000 cycles. The percentage transmittance of a PProDOS-C10 film was found to be 56.4% at 638 nm and 55.8% at 700 nm. Furthermore, this novel soluble PProDOS-C10 polymer shows an electrochromic behavior: a color change from pure blue to a highly transparent state in a low switching time (1.0 s) during oxidation, with high coloration efficiencies (328 cm 2 C-1 at 638 nm and 319 cm(2) C-1 at 700 nm) when compared to its thiophene analogue

    Developmental dysplasia of the hip associated with aplasia of the pubic bone (hook-pelvis): report of a case and review of the literature

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    WOS: 000357593100007PubMed ID: 25153647Aplasia of the pubic bone associated with congenital hip dislocation is rare. Various dysmorphic conditions featuring absence or hypoplasia of the ischiopubic bone, associated with congenital hip dislocation, have been distinguished in the literature. We report the case of an 18-month-old boy with developmental dysplasia of the hip associated with isolated total aplasia of the pubic bone. Patient was successfully treated with modified Salter osteotomy and reverse U-shaped capsuloplasty. (C) 2014 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

    Substituent and heteroatom effects on the electrochromic properties of similar systems

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    Electrochromic polymers called poly(3,4-dihydro-3,3-bis ((naphthalen-1-yl)methyl)-2H-thieno[3,4-b][1,4]dioxepine) (PProDOT-Np-2), poly(3,3-dibenzyl-3,4-dihydro-2H-selenopheno[3,4-b][1,4]dioxepine), and poly(3,3-dibenzyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine) were synthesized electrochemically and the effect of substituents and heteroatoms on the electrochromic properties were investigated for the similar systems. All polymers show electrochromism from a colored state when neutralized to transmissive when oxidized. Although, increasing bulky size (PProDOT-Np-2) causes lower coloration efficiency (CE) as well as lower optical contrast, the replacement of S atom by Se atom resulted in a lower band gap polymer with a higher CE than its thiophene analog. (c) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 615- 621, 201

    Donor-acceptor polymer electrochromes with cyan color: Effect of alkyl chain length on doping processes

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    A new series of donor-acceptor-donor (D-A-D) type compounds consisting of dialkyl substituted 3,4-propylenedioxythiophene and benzothiadiazole units were synthesized and polymerized chemically and electrochemically to investigate the effect of alkyl chain length on the doping process of the conjugated polymers. It was found that the alkyl chain length plays a key role on both doping processes and the solubility of the polymer. It is also noteworthy that this new series of D-A-D electrochromes transmits or reflects the cyan color of the Cyan-Magenta-Yellow (CMY) color space in the neutral state which can be switched to transmissive grey when oxidized
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