bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel electroactive poly(arylene ether sulfone) copolymers containing pendant oligoaniline groups: Synthesis and properties
Authors: Chao Danming , Jia Xiaoteng , Liu Hongtao , He Libing , Cui Lili , Wang Ce , Berda Erik B. 
Published: February 2011

AbstractWe present a series of novel poly(arylene ether sulfone) copolymers containing pendant oligoaniline groups. A novel monomer containing oligoaniline, 2,6‐difluorobenzoyl aniline tetramer (DFAT), was synthesized by reaction of 2,6‐difluorobenzoyl chloride and parent aniline tetramer and incorporated into the aforementioned copolymers via direct copolymerization with 4,4′‐dichlorodiphenyl sulfone (DCDPS), and 4,4′‐isopropylidene diphenol (BPA) using N,N′‐dimethylacetamide as solvent. The structures of these copolymers were confirmed by FTIR, 1H NMR, and GPC. Spectral analysis of the copolymers in different oxidation states was investigated via UV‐visible spectra. The copolymers exhibited outstanding thermal stability and good solubility in various organic solvents. Their electroactivity, explored with cyclic voltammetry, was found to increase as the content of oligoaniline in the polymer increased. The electric and dielectric properties of the copolymers were also studied in detail. The electrochromic performance of the copolymers was investigated by electrochromic photographs and transmittance spectra; the color of the copolymer thin films changes from grey (at 0.0 V), to green (at 0.4 V), to blue (at 0.6 V) and to pearl blue (at 1.0 V) and the maximum transmittance change (ΔT) at 700 nm is 42.6% (90.7% ↔ 48.1%). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis and characterization of polystyrene‐graphite nanocomposites via surface RAFT‐mediated miniemulsion polymerization
Authors: Etmimi Hussein M. , Tonge Matthew P. , Sanderson Ronald D. 
Published: February 2011

AbstractGraphite oxide (GO) was prepared and immobilized with dodecyl isobutyric acid trithiocarbonate (DIBTC) reversible addition‐fragmentation chain transfer (RAFT) agent. The hydroxyl groups of GO were attached to the DIBTC RAFT agent through an esterification process. The resultant modified GO was used for the preparation of polystyrene (PS)/graphite nanocomposites in miniemulsion polymerization. The RAFT‐grafted GO (GO‐DIBTC) at various loadings was dispersed in styrene monomer, and the resultant mixtures were sonicated in the presence of a surfactant (sodium dodecylbenzene sulfonate) and a hydrophobe (hexadecane) to form miniemulsions. The stable miniemulsions thus obtained were polymerized using azobisisobutyronitrile as the initiator to yield encapsulated PS‐GO nanocomposites. The molar mass and polydispersity index of PS in the nanocomposites depended on the amount of RAFT‐grafted GO in the system, in accordance with the features of the RAFT polymerization method. The PS‐GO nanocomposites were of exfoliated morphology, as confirmed by X‐ray diffraction and transmission electron microscopy measurements. The thermal stability and mechanical properties of the PS‐GO nanocomposites were better than those of the neat PS polymer. Furthermore, the mechanical properties were dependent on the modified GO content (i.e., the amount of RAFT‐grafted GO). © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Conversion of poly(ethylene‐alt‐tetrafluoroethylene) copolymers into polytetrafluoroethylene by direct fluorination: A convenient approach to access new properties at the ETFE surface
Authors: Calleja Gérard , Houdayer Axel , Etienne‐calas Sylvie , Bourgogne David , Flaud Valérie , Silly Gilles , Shibahara Sota , Takahara Atsushi , Jourdan Alex , Hamwi André , Ameduri Bruno 
Published: February 2011

AbstractDirect fluorination of poly(ethylene‐alt‐tetrafluoroethylene) copolymer (ETFE) was carried out on commercially available ETFE films with pure fluorine gas at ambient atmosphere. Reaction temperature was either 95 °C or 150 °C and exposure time was 20 hours. Analysis of the fluorinated samples was performed by attenuated total reflection Fourier transform Infrared, confocal micro‐Raman and 1H and 19F magic angle spinning nuclear magnetic resonance spectroscopies, scanning electron microscopy, electron diffraction and X‐Ray photoelectron spectroscopies, contact angle determination, atomic force microscopy and nanoindentation measurements, and compared to those of the virgin ETFE copolymer. Integrity of the bulk materials was verified by investigating the thermal behavior of the polymers by thermogravimetric analysis and differential scanning calorimetry. Evidence for the formation of a homogeneous layer of polytetrafluoroethylene with a thickness of several microns at the surface of the copolymers with no degradation of the materials was observed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis of poly(p‐phenylene)‐poly(4‐diphenylaminostyrene) bipolar block copolymers with a well‐controlled and defined polymer chain structure
Authors: Natori Itaru , Natori Shizue , Sekikawa Hiroyuki , Tsuchiya Kosuke , Ogino Kenji 
Published: February 2011

AbstractA poly(p‐phenylene) (PPP)‐poly(4‐diphenylaminostyrene) (PDAS) bipolar block copolymer was synthesized for the first time. A prerequisite prepolymer, poly(1,3‐cyclohexadiene) (PCHD)‐PDAS binary block copolymer, in which the PCHD block consisted solely of 1,4‐cyclohexadiene (1,4‐CHD) units, was synthesized by living anionic block copolymerization of 1,3‐cyclohexadiene and 4‐diphenylaminostyrene. To obtain the PPP‐PDAS bipolar block copolymer, the dehydrogenation of this prepolymer with quinones was examined, and tetrachloro‐1,2‐(o)‐benzoquinone was found to be an appropriate dehydrogenation reagent. This dehydrogenation reaction was remarkably accelerated by ultrasonic irradiation, effectively yielding the target PPP‐PDAS bipolar block copolymer. The hole and electron drift mobilities for PPP‐PDAS bipolar block copolymer were both on the order of 10−3 to 10−4 cm2/V·s, with a negative slope when plotted against the square root of the applied field. Therefore, this bipolar block copolymer was found to act as a bipolar semi‐conducting copolymer. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Induction and inversion of chirality in poly‐L‐lysine and methyl orange complex
Authors: Takahashi Daisuke , Tanabe Ryoichi , Izumi Tsuyoshi 
Published: February 2011

AbstractThe mechanism of complexation of poly‐L‐lysine (PLL) with methyl orange (MO) and the appearance of induced circular dichroism (ICD) were investigated as a function of dye concentration and temperature and compared with that of the PLL‐ethyl orange complex. The formation of stoichiometric complexes with uniform size and intensities of ICDs depended on the length of alkyl groups (methyl and ethyl) as determined from quartz crystal microbalance measurement, absorption spectra, and CD spectra data. Furthermore, at constant PLL concentration, a dependence of the inversion of the ICD on the MO concentration (CMO) was observed in the PLL‐MO complexes, which to our knowledge has not been reported for a constant dye concentration system. The positive ICD in the PLL‐MO complexes observed at CMO lower than 2.0 × 10−5 M showed reversible changes in response to heating and cooling, whereas the negative ICD in PLL‐MO complexes observed at higher CMO inverted to positive ICD values in response to a decrease in temperature. These results demonstrate the alkyl group substituent in the dye, dye concentration, and temperature play important roles in the formation of PLL‐azo dye complex and ICD appearance. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Poly(siloxane‐urethane) crosslinked structures obtained by sol‐gel technique
Authors: Alexandru Mihaela , Cazacu Maria , Cristea Mariana , Nistor Alexandra , Grigoras Cristian , Simionescu Bogdan C. 
Published: February 2011

AbstractPoly(siloxane‐urethane) crosslinked structures were prepared from isophorone diisocyanate, α,ω‐bis(hydroxybutyl)oligodimethylsiloxane and a new hybrid diol containing hydrolysable SiOC2H5 groups besides OH groups. The latest was synthesized by the acid‐catalyzed reaction between 1,3‐bis(3‐glycidoxypropyl)tetramethyldisiloxane and 3‐aminopropyltriethoxysilane. The formations of the urethane groups along the polymer backbone as well as the formation of the silica domains were first confirmed by the presence of the specific bands in Fourier transform infrared spectra. The resulted materials were characterized using differential scanning calorimetry, thermogravimetric analysis and scanning electron microscopy. The results of the dynamic mechanical analysis (DMA) performed at various frequencies revealed shape memory capabilities for some of the obtained structures. The silica formed because of the hydrolysis‐condensation reactions proved to have reinforcing effect upon siloxane‐urethane structure also evidenced by DMA and increasing water vapor sorption capacity as was measured by dynamic vapor sorption. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
DNA hydrogels: New functional soft materials
Authors: Okay Oguz 
Published: February 2011

AbstractDeoxyribonucleic acid (DNA) hydrogel is a network of crosslinked DNA strands swollen in aqueous solutions. The crosslinks may be physical or chemical, such as the hydrogen bonds or ethylene glycol units, respectively, connecting the strands belonging to different double‐helical DNA molecules. As DNA network strands in the hydrogels exhibit properties similar to those of the individual DNA molecules, such soft materials are a good candidate to make use of the characteristics of DNA such as coil‐globule transition, biocompatibility, selective binding, and molecular recognition. Physical DNA hydrogels with an elastic modulus in the order of megapascals can be prepared by subjecting semidilute aqueous solutions of DNA to successive heating–cooling cycles between below and above the melting temperature of DNA. Chemical DNA hydrogels can be prepared by connecting the amino groups on the nucleotide bases through covalent bonds to form a three‐dimensional DNA network in aqueous solutions. In this article, we summarize the preparation strategies of DNA hydrogels with a wide range of tunable properties. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Mechanisms of large actuation strain in dielectric elastomers
Authors: Koh Soo Jin Adrian , Li Tiefeng , Zhou Jinxiong , Zhao Xuanhe , Hong Wei , Zhu Jian , Suo Zhigang 
Published: February 2011

AbstractSubject to a voltage, a dielectric elastomer (DE) deforms. Voltage‐induced strains of above 100% have been observed when DEs are prestretched, and for DEs of certain network structures. Understanding mechanisms of large actuation strains is an active area of research. We propose that the voltage‐stretch response of DEs may be modified by prestretch, or by using polymers with “short” chains. This modification results in suppression or elimination of electromechanical instability, leading to large actuation strains. We propose a method to select and design a DE, such that the actuation strain is maximized. The theoretical predictions agree well with existing experimental data. The theory may contribute to the development of DEs with exceptional performance. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Sulfur and carbon isotopes within atmospheric, surface and ground water, snow and ice as indicators of the origin of tabular ground ice in the Russian Arctic
Authors: Leibman M.O. , Kizyakov A.I. , Lein A. Yu. , Perednya D.D. , Savvichev A.S. , Vanshtein B.G. 
Published: February 2011

AbstractField sampling of tabular ground ice (TGI) was undertaken at a number of geological sections along the Russian Arctic coast. 34S in sulfate ion and 13C in organic matter were analysed in ground ice and enclosing deposits, and in reference samples from snowpacks, atmospheric precipitation, surface waters and glaciers. The scatter in the stable isotope data obtained indicates the heterogeneity of moisture sources for TGI formation. There is a notable difference in the sulfur and carbon isotopic structure between TGI and atmospheric and continental moisture. TGI and its enclosing deposits have a heavier isotopic composition of sulfur and carbon than buried snow and glacial ice. This is considered to be evidence of an essential contribution of marine moisture and sediments to TGI formation. Copyright © 2011 John Wiley & Sons, Ltd.
Lobe‐specific lineages of carcinogenesis in the transgenic adenocarcinoma of mouse prostate and their responses to chemopreventive selenium
Authors: Wang Lei , Zhang Jinhui , Zhang Yong , Nkhata Katai , Quealy Emily , Liao Joshua D. , Cleary Margot P. , Lü Junxuan 
Published: February 2011

AbstractBACKGROUNDThe transgenic adenocarcinoma of mouse prostate (TRAMP) model is by far the most practical transgenic model for preclinical prostate cancer chemoprevention studies. It is critical to characterize the prostate lobe‐specificity of lesion lineages to consolidate the advantages of this model and minimize its limitations for chemoprevention studies.METHODSWe dissected dorsolateral (DLP), ventral (VP), and anterior prostate (AP) lobes, and macroscopic tumors from 90 male C57BL/6J TRAMP mice at 22–24 weeks of age (WOA) and analyzed lesions by histological, biochemical and proteomic approaches. To determine whether methylseleninic acid (MSeA) led to a deletion of initiated cells, we gave oral MSeA to TRAMP mice from 5 to 23 WOA or from 5 to 15 WOA and analyzed lesions at 23 WOA.RESULTSAll tumors (n = 18) were T‐antigen(+), synaptophysin (SYP)(+), androgen‐receptor(−), and E‐cadherin(−) poorly differentiated neuroendocrine carcinomas (NE‐Ca). They were traceable most frequently to VP (66.7%) and rarely to DLP (11.1%) and AP (5.6%) with an estimated life‐time incidence of 1 out of 3 mice. In DLP, epithelial lesions ranged from mild‐to‐severe atypical hyperplasia, with T‐antigen(+), SYP(−), androgen‐receptor(+), and E‐cadherin(+). Proteomic profiling revealed many molecular differences between VP and DLP. In MSeA experiment, 6 out of 19 (31.5%) mice developed NE‐Ca in the control group, only 2 in each MSeA group of 17–18 mice (11.1–11.8%) bore a detectable NE‐Ca.CONCLUSIONThe C57BL/6J TRAMP mouse represents at least two lineages of prostate carcinogenesis. Chemoprevention studies should incorporate this knowledge for efficacy assessment and molecular target validations. Prostate 71:1429–1440, 2011. © 2011 Wiley‐Liss, Inc.
Metabolic syndrome is associated with high grade gleason score when prostate cancer is diagnosed on biopsy
Authors: De Nunzio Cosimo , Freedland Stephen J , Miano Roberto , Trucchi Alberto , Cantiani Andrea , Carluccini Alfonso , Tubaro Andrea 
Published: February 2011

AbstractBACKGROUNDTo evaluate the association between metabolic syndrome (MS) and prostate cancer diagnosis and grade in patients undergoing prostate biopsy.METHODSFrom 2009 onwards, a consecutive series of patients undergoing 12‐core prostate biopsy for PSA value ≥4 ng/ml and/or positive digital rectal examination (DRE) were prospectively enrolled. Body mass index (BMI), waist circumferences, and blood pressure were measured before the biopsy. Blood samples were tested for: PSA, fasting glucose, triglycerides, and cholesterol HDL. MS presence was defined according to Adult Treatment Panel III criteria.RESULTSOne hundred ninety five patients were enrolled with a median age and PSA of 69 years and 5.6 ng/ml respectively. Median BMI was 27.6 kg/m2 with 64 patients (33%) being classified as obese (BMI ≥ 30 kg/m2). Eighty‐six patients (44%) had MS. Eighty‐three patients (43%) had cancer on biopsy; 37 (45%) with MS and 46 (55%) without (P = 0.48). PSA was independently associated with higher risk of cancer (OR 1.12/1 U PSA, P = 0.01). Out of 83 patients with prostate cancer, 42 (51%) had Gleason score 6 (12 (28.5%) presented a MS) and 41 (49%) a Gleason score ≥7 (25 (61%) presented a MS). The presence of MS was not associated with an increased risk prostate cancer (OR: 0.97, P = 0.94) but with an increased risk of Gleason ≥7 (OR: 3.82; P = 0.013).CONCLUSIONSIn our single center study, MS is associated with an increased risk of high grade Gleason score when prostate cancer is diagnosed on biopsy. However, these results should be confirmed in a larger multicenter study. Prostate 71:1492–1498, 2011. © 2011 Wiley‐Liss, Inc.
Combined effect of nucleopolyhedrovirus and Microplitis pallidipes for the control of the beet armyworm, Spodoptera exigua
Authors: Jiang Jiexian , Zeng Aiping , Ji Xiangyun , Wan Nianfeng , Chen Xiaoqin 
Published: February 2011

AbstractBACKGROUND: Nucleopolyhedrovirus (SeNPV) and Microplitis pallidipes are important biological control agents of Spodoptera exigua populations. The interactions between these agents and their combined effect on pest control were investigated in the laboratory and in commercial greenhouses.RESULTS: Microplitis pallidipes searched for and deposited eggs in more healthy larvae than virus‐infected larvae 3 days after viral infection. Each female parasitoid that developed in a virus‐infected host oviposited in a virus‐infected host, or emerged from a cocoon carrying virus transmitted to 4.0, 7.6 or 2.4 healthy larvae respectively. Each female parasitoid exposed to a mixture of virus and 10% honey water solution transmitted the virus to 2.2 healthy larvae. In an experiment with cabbage growing in commercial greenhouses, the pest population reduction was greater by M. pallidipes carrying SeNPV (82.3–89.7% reduction) than by parasitoids without virus (59.5–62.4% reduction).CONCLUSIONS: Control of S. exigua was greater with M. pallidipes plus SeNPV than with M. pallidipes alone. Microplitis pallidipes preferred healthy hosts to infected hosts. Parasitoids were able to complete their development in virus‐infected hosts before the hosts died from the virus infection. The parasitoid ovipositors contaminated with the virus could carry and transmit SeNPV. Copyright © 2011 Society of Chemical Industry
Composition of essential oil of Chinese Chenopodium ambrosioides and insecticidal activity against maize weevil, Sitophilus zeamais
Authors: Chu Sha Sha , Feng Hu Jin , Liu Zhi Long 
Published: February 2011

AbstractBACKGROUND: In a screening programme for new agrochemicals from Chinese medicinal herbs, Chenopodium ambrosioides L. was found to possess strong fumigant activity against the maize weevil Sitophilus zeamais (Motsch.). Essential oil of C. ambrosioides was obtained by hydrodistillation, and the constituents were determined by GC‐MS analysis. The active compounds were isolated and identified by bioassay‐directed fractionation.RESULTS: Five active compounds [(Z)‐ascaridole, 2‐carene, ρ‐cymene, isoascaridole and α‐terpinene] were isolated and identified from the essential oil from Chinese C. ambrosioides. The LC50 values (fumigation) of the crude essential oils and the active compound (Z)‐ascaridole against S. zeamais adults were 3.08 and 0.84 mg L−1 air respectively. The LD50 values (contact toxicity) of the crude essential oil and (Z)‐ascaridole against S. zeamais adults were 2.12 and 0.86 µg g−1 body weight respectively.CONCLUSION: The findings suggested that the essential oil of Chenopodium ambrosioides and its main active constituent, (Z)‐ascaridole, may be explored as a natural potential fumigant. Copyright © 2011 Society of Chemical Industry
Characterization of antilytic peptide antibody: application for the detection of lytic‐based hybrid peptide in serum samples
Authors: Ohara Koji , Horibe Tomohisa , Kohno Masayuki , Kawakami Koji 
Published: February 2011

AbstractWe previously reported that a novel targeted drug termed hybrid epidermal growth factor receptor (EGFR)‐lytic peptide, made by chemical conjugation of targeted binding peptide and cell‐killing, lytic‐peptide components, has selective cytotoxic activity that allows it to discriminate between normal and cancer cells. In addition, in vivo analysis revealed that this hybrid peptide displays significant antitumor activity in a xenograft model of human breast and pancreatic cancer in mice. Here, we characterized antilytic peptide antibody, which was raised from rabbit serum using the antigen of lytic peptide conjugated with keyhole limpet hemocyanin. It was found that antilytic peptide antibody is specific to the lytic peptide as assessed by both ELISA and surface plasmon resonance analysis and can also bind to EGFR‐lytic peptide. Epitope mapping analysis using Biacore showed that two successive lysine regions in the lytic‐peptide sequence are significant for recognition by this antibody. In addition, it was shown that this antibody can detect lytic‐based hybrid peptide in serum samples from mouse blood and also in cultured breast cancer MDA‐MB‐231 cell samples by immunocytochemical staining experiments. It was found that the maximum concentrations of this peptide in serum were reached within 15–30 min of i.v. administration of EGFR‐lytic peptide to mice. These results indicate that this antibody will be a useful tool for the detection of lytic‐based peptides to investigate their in vivo stability and pharmacokinetics. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Structural and magnetic phenomena in ultrathin C/Co/C stacks prepared by DC magnetron sputtering
Authors: Zolotaryov A. , Bugayev Ye. , Samofalov V. , Devizenko O. , Zubarev E. , Martens S. , Albrecht O. , Görlitz D. , Nielsch K. 
Published: February 2011

AbstractWe study two C(5 nm)/Co/C(5 nm) multilayer stacks with cobalt layer thicknesses of 4 and 13 nm. Structural analysis of fabricated systems reveals corresponding cobalt layers to be in amorphous (nanocrystalline) and [0001]‐textured hcp‐phase. The magnetic measurements for both systems agree well with structural data. For the amorphous cobalt layer magnetic data reveal the absence of carbides, high saturation field of 1.6 × 104 Oe and vanishing inplane coercive field. We also show that strong inplane anisotropy can be introduced into the amorphous cobalt film by controlling the process parameters of DC‐magnetron sputtering. For the textured hcp‐cobalt film we have deduced the presence of randomly close‐packed (rcp) structure. We assume this defect‐rich cobalt hcp‐phase to be responsible for the detected elimination of the out‐of‐plane magnetic anisotropy in the corresponding multilayer sample.
Misfit stresses and relaxation mechanisms in a nanowire containing a coaxial cylindrical inclusion of finite height
Authors: Gutkin Mikhail Yu. , Kuzmin Konstantin V. , Sheinerman Alexander G. 
Published: February 2011

AbstractA model is suggested that describes stress relaxation in a nanowire with a finite‐height cylindrical inclusion (quantum dot). The stress field created in the nanowire by such an inclusion is calculated. Two different mechanisms of stress relaxation in a nanowire with a cylindrical inclusion are proposed and analyzed. The first mechanism involves the formation of a prismatic misfit dislocation loop around the inclusion while the second mechanism suggests the formation of a penny‐shaped crack in the inclusion cross section. It is shown that both mechanisms of stress relaxation can be realized in wide ranges of the structural and geometric parameters of the nanowire and inclusion. It is also demonstrated that in most cases the formation of a dislocation loop is more preferable than the formation of a penny‐shape crack, although in some situations, crack generation becomes more preferable.