bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploring quality of life perceptions in rural midwestern (USA) communities: an application of the core–periphery concept in a tourism development context
Authors: Chancellor Charles , Yu Chia‐Pin Simon , Cole Shu Tian 
Published: November 2010

ABSTRACTTourism has increasingly become a preferred option for rural economic development. Like other economic opportunities, the purpose is to improve community viability and residents' quality of life. However, the impacts from tourism are sometimes negative and may lead to a decreased quality of life for residents. This empirical study investigates residents' quality of life using the core–periphery (CP) model. Periphery respondents reported a statistically higher overall quality of life, which is at odds with other research. Significant differences in quality of life scores and subsequent indicators highlight the usefulness of the CP model towards understanding tourism impacts to a rural destination. Copyright © 2010 John Wiley & Sons, Ltd.
Constitutive release of powerful antioxidant-scavenging activity by hepatic stellate cells: Protection of hepatocytes from ischemia/reperfusion injury
Authors: Jameel Noor Mohamed , Thirunavukkarasu Chinnasamy , Murase Noriko , Cascio Michael , Prelich John , Yang Shuting , Harvey Stephen A. K , Gandhi Chandrashekhar R 
Published: November 2010

Abstract
Within the liver, reactive oxygen species produced by infiltrating blood cells and Kupffer cells (resident macrophages) can injure hepatocytes. We hypothesized that hepatocyte survival is influenced by the relatively small juxtaposed population of hepatic stellate cells (HSCs). We used cultures of primary rat hepatocytes as targets for superoxide-induced damage, which was determined by crystal violet assay and lactate dehydrogenase release. An HSC-conditioned medium prevented the superoxide-induced death of hepatocytes, and the protective factor released by HSCs was a protein or proteins (apparent molecular weight > 100 kDa) resistant to heat (70°C) and pH (4.5-8.5). The protein or proteins were partially purified on DE52 cellulose, and the active fraction contained no detectable levels of superoxide dismutase: after separation by Sephadex G-100 gel filtration, the antioxidant activity could be reconstituted by the combination of 2 protein peaks, and this reconstituted activity was protective both in vitro and against liver ischemia/reperfusion injury in intact rats. Mass spectrometry proteomic studies confirmed that this activity could not be attributed to any previously identified antioxidant protein. Thus, HSCs protect hepatocytes against oxidative damage through the production of a novel protein, the further purification of which may lead to the isolation of a powerful oxygen radical scavenger with clinical applications. Liver Transpl 16:1400–1409, 2010. © 2010 AASLD.
Thermo‐Responsive Polymer Brushes as Intelligent Biointerfaces: Preparation via ATRP and Characterization
Authors: Nagase Kenichi , Watanabe Minami , Kikuchi Akihiko , Yamato Masayuki , Okano Teruo 
Published: November 2010

AbstractPIPAAm‐brush grafted glass substrates with various graft densities and chain lengths were prepared via surface‐initiated ATRP. Temperature‐dependent physicochemical properties of the surfaces were characterized by means of ATR/FT‐IR spectroscopy, XPS, AFM, and contact angle measurements. ATRP conditions influence the amount of grafted PIPAAm and the surface wettability and roughness of the substrate. Fibronectin adsorption and EC adhesion increased with decreasing density of PIPAAm brushes. EC adhesion was diminished with increasing PIPAAm graft length. Thus, the preparation of PIPAAm brush surface with various graft densities and chain lengths using the surface‐initiated ATRP is an effective method for modulating thermo‐responsive properties of surfaces.
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Preparation of Poly(p‐phenylenepyromelliteimide) Microspheres with Rugged Surfaces Using Crystallization During Isothermal Polymerization
Authors: Wakabayashi Kanji , Uchida Tetsuya , Yamazaki Shinichi , Kimura Kunio 
Published: November 2010

AbstractPreparation of discrete PPPI microspheres was examined using the crystallization of oligomers during isothermal polymerization of PMDA and p‐phenylene diisocyanate, and that of pyromellitic dithioanhydride and PPDA in poor solvents. In contrast to PPPI microspheres with smooth surfaces that were previously prepared by phase‐separation during the polymerization of PPDA and PMDA, the microspheres obtained here consisted of flake‐like lamellae with rugged surfaces. The diameters of the microspheres ranged from 0.5 to 6.7 µm. They exhibited excellent thermal stability depending on the monomers. These results provide a new preparative procedure of the PPPI microsphere with a rugged surface. magnified image
Hydroxy Functional Acrylates: Enzymatic Synthesis and Free Radical Polymerization
Authors: Popescu Dragos , Hoogenboom Richard , Keul Helmut , Möller Martin 
Published: November 2010

AbstractHydroxy functional acrylates were prepared via transacylation of methyl acrylate with 1,2,6‐hexanetriol catalyzed by Candida antarctica lipase B. Under the applied reaction conditions, 70% of the substrate was converted into hydroxy functional acrylates. In a subsequent step, after filtration of the enzyme, the monomer mixture containing methyl acrylate and the new monomers was polymerized via free radical polymerization resulting in a functional copolymer with Mn = 14500 g/mol.
Graft and RAFT Reactive Macro Reagents: Bis‐[copoly‐(divinyl ether‐alt‐maleic anhydride)]‐trithiocarbonate
Authors: Serbin Alexander , Karaseva Ekaterina , Chernikova Elena , Dunaeva Irina , Krutko Ekaterina , Filatova Marina , Zezin Alexander 
Published: November 2010

AbstractThe alternating cyclocopolymer of maleic anhydride with divinyl ether (MADVE) hydrolyzate, as mimicker of furan related and anionic residues alternation in nucleic acids (NA) backbone, is immune stimulating agonist and competitive antagonist for viral genome NA interventions. The targeted pre‐modification of MADVE by antiviral vectors via grafting to the MA anhydride residues before hydrolysis led to more potent and promising antiviral inhibitors. To develop the MADVE capacity for novel modifications we applied the reversible addition – fragmentation chain transfer (RAFT) technique using dibenzyl trithiocarbonate as a RAFT agent. The insertion of trithiocarbonate unit in polymeric chain provided a pseudo living RAFT‐polymerization, resulting in: 1) the effective control of polymerization degree (increased with time and conversion), and 2) the narrow dispersive (PDI = 1.1–1.2) products MADVE‐S‐CS‐S‐MADVE yield. These products can be used as novel polymeric RAFT‐agents for synthesis of new block‐copolymers MADVE‐(block)‐CS3‐(block)‐MADVE, for instance with polystyrene blocks. Combined together the RAFT‐ and graft‐ reactivity allows both modify the polymer backbone (RAFT‐synthesis) and regulate the side groups or branches (grafted to MADVE moieties) with final hydrolysis of unused anhydride units to acidic polyelectrolyte derivatives. This plural reactive capacity of the obtained macro reagents essentially enhances their potential as platform for purposed synthesis of novel (bio‐) functional polymeric compounds.
Synthesis and Characterization of Novel Sulfonated Hybrid Congo Red Membranes from Chlorofunctionalized Silsesquioxanes for Fuel Cell Application
Authors: Gültek Ahmet , Gökçen Yusuf , Köytepe Süleyman , Seçkin Turgay 
Published: November 2010

AbstractA new sulfonated copolymers containing congo red groups were synthesized as a potential electrolyte for high temperature PEFCs. The resulting cross‐linked sulfonated hybrid congo red membranes showed greatly improved water stability in comparison with the uncrosslinked ones while high proton conductivity was maintained. sulfonated membranes have been tested with respect to fuel cell performance. Short term fuel cell test for 100 hr gave a stable performance. These membranes are less expensive compared to Nafion. New sulfonated proton exchange composites membranes were used biological fuel cells. Molasses which is the waste of sugar factory, was used in anode as fuel and different bacteria species was sowing. Potential change was reported in biological fuel cells.
Synthesis of New Anionic and Cationic Polymerizable Surfactants for Emulsion Polymerization of Styrene
Authors: Mekki Sofiane , Saïdi‐Besbes Salima , Elaïssari Abdelhamid , Valour Jean‐Pierre , Derdour Aïcha 
Published: November 2010

AbstractNew anionic and cationic maleic surfmers containing a benzyl or p‐vinylbenzyl hydrophobic tail were prepared and characterized. The behaviour of benzyl maleate hemiester in the emulsion polymerization process of styrene has been studied in the presence of potassium persulfate as initiator. The effect of surfmer concentration on particle diameter was particularly investigated.
Self‐Processing, Diffusion‐Based Photopolymers for Holographic Applications
Authors: Weiser Marc‐Stephan , Bruder Friedrich‐Karl , Fäcke Thomas , Hönel Dennis , Jurbergs David , Rölle Thomas 
Published: November 2010

AbstractThe new photopolymers for holographic applications described herein are based on a cross‐linked matrix in which the holographic grating is formed by photo‐polymerization of guest monomers in an interference pattern of the recording light. Diffusion of monomer, triggered by this photo‐polymerization, from the dark to the bright fringes of the interference pattern is the key parameter for creating high modulation in refractive index Δn during hologram recording. This leads to bright visual volume holograms with high diffraction efficiency. The holographic photopolymers are self‐processing. After recording the hologram only (incoherent) light exposure is necessary to bleach the final product and fix the hologram. Unlike earlier photopolymers used in holography, these new materials offer the advantages of no chemical or thermal processing combined with low shrinkage and detuning. Additionally, due to good light sensitivity the formation of the holograms is fast and the film obtained after curing is highly transparent, which makes the material suitable for both, reflection and transmission holography.
Enhanced Photostability and Red‐NIR Photosensitivity of Conjugated Polymer Charge‐Transfer Complexes
Authors: Ozimova Anastasiya E. , Bruevich Vladimir V. , Dittrich Thomas , Paraschuk Dmitry Yu. 
Published: November 2010

AbstractA promising route to photostable and low‐bandgap polymer materials for optoelectronic and photonic applications could be utilization of donor‐acceptor ground‐state charge‐transfer complexes (CTCs) of wide‐bandgap conjugated polymers. In this work, we report our results on photostability and photoelectric studies of CTC between an archetypical conjugated polymer MEH‐PPV and low‐molecular‐weight acceptor 2,4,7‐trinitrofluorenone (TNF). By using the pump‐probe laser photobleaching technique, we show that the photodegradation rate of MEH‐PPV:TNF blend films decreases up to four orders of magnitude as compared with pristine MEH‐PPV. By using photocurrent and surface photovoltage spectroscopies, we demonstrate that the photoelectric sensitivity of the MEH‐PPV:TNF CTC can be deeply extended in the polymer optical gap down to 1 µm. However, the main drawback of the CTC studied is their low charge collection efficiency, and an approach to increasing it is discussed.
Micellization and Thermogelation of Poly(ether urethane)s Comprising Poly(ethylene glycol) and Poly(propylene glycol)
Authors: Loh Xian Jun , Cheng Lim Wan Ian , Li Jun 
Published: November 2010

AbstractA series of multiblock poly(ether urethane)s comprising poly(ethylene glycol) (PEG), and poly(propylene glycol) (PPG) segments were synthesized. Their aqueous solutions exhibited thermogelling behavior at critical gelation concentrations (CGC) ranging from 8 to 12 wt%. The composition and structural information of the copolymers were studied by GPC and 1H NMR. The critical micellization concentration (CMC) and thermodynamic parameters for micelle formation were determined at different temperatures. The temperature response of the copolymer solutions were studied and found to be associated with the composition of the copolymers.
Characterization of the Orientation Parameters Around Crack Tips in Unfilled and Nanofilled Poly(propylene) Using in‐situ Synchrotron Small and Wide Angle Scanning Scattering Techniques
Authors: Feuchter Michael , Maier Günther , Zizak Ivo , Pinter Gerald , Kracalik Milan , Laske Stephan , Langecker Günter Rüdiger 
Published: November 2010

AbstractThe fracturing behavior of polymers and polymeric composites is of great interest in the scientific and application community. Especially in the case of silicate‐layered nanocomposites the influence of fillers on the fracturing behavior is still fairly unclear. Fractures of semicrystalline polymers are accompanied by various processes of which shearing and cavitations are the most common ones. Nanocomposite deformation due to the delamination of fillers seems to be the most practical way leading to fractures with relatively low strains. With the method of scanning small angle X‐ray scattering (SAXS) and wide angle X‐ray diffraction (WAXD) it is possible to combine information on the structural details with the position on the sample, with the actual position resolution of the investigation being defined by the size of the X‐ray beam used to scan the sample. By means of the application of synchrotron radiation it is nowadays possible to adjust the actual beam size to the dimensions of the region of interest, which is why it is an adequate tool for studying the deformation region near a crack tip.In a native polypropylene sample, the fracturing process was accompanied by shear yielding as well as lamellae fragmentation and reorienting. In the highly deformed material near the crack tip fibrillated material could be found. However, in the polymeric nanocomposites (PNC) shearing, lamellae fragmentation, and fibrillation were hindered by the filler due to which the material did not have so much freedom to dissipate energy and fractures occurred much earlier. In this paper the comparison of a PNC and its native polymer is to provide an overview of the different deformation mechanism and the structural details around the crack tip.
Thermal and DMA Characterization of PTFE‐PMMA Nanocomposites from Core‐Shell Nanoparticles
Authors: Antonioli Diego , Laus Michele , Sparnacci Katia , Deregibus Simone , Kapeliouchko Valerj , Palamone Giovanna , Poggio Tiziana , Zuccheri Giampaolo , Passeri Rosita 
Published: November 2010

AbstractThe thermal and dynamic‐mechanical characteristics of three PTFE/PMMA nanoparticle samples are described. The shell forming PMMA, once isolated from the PTFE cores, exhibits a lower thermal stability than the PMMA component in the corresponding nanocomposite under both thermal and oxidative degradation conditions thus indicating a definite, though moderate, thermal reinforcement due to the morphology of the nanocomposites. An increase in the thermal stability under nitrogen atmosphere was observed as the PTFE amount increases. However under air, no difference is observed in the various systems. These observations suggest that only a physical shield can be exerted by the PTFE cores to the PMMA matrix possibly due to a weak interface between PTFE and the PMMA. This hypothesis is also substantiated by the DMA analysis.
FTIR‐ATR Monitoring and SEC/RI/MALLS Characterization of ATRP Synthesized Hyperbranched Polyacrylates
Authors: Gonçalves Miguel A. D. , Pinto Vigínia D. , Dias Rolando C. S. , Costa Mário Rui P. F. N. 
Published: November 2010

AbstractThis work reports the synthesis at 1 L scale of hyperbranched polyacrylates based upon acrylate/diacrylate monomers such as n‐butyl acrylate (nBA)/1,6‐hexanediol diacrylate (HDDA) and using atom transfer radical polymerization (ATRP). A FTIR‐ATR immersion probe was used to monitor the polymerization reaction. The dynamics of the build‐up of polymer structure was studied by off‐line analysis of samples at different reaction times by size exclusion chromatography (SEC) with detection of refractive index (RI) and multi‐angle laser light scattering (MALLS) signals, leading to molecular weight distribution and z‐average radius of gyration. Kinetic measurements and observed parameters of the molecular architecture are compared with theoretical predictions which can be used to design new synthesis strategies to improve the homogeneity of hyperbranched polymers. Another goal of this study was elucidating the impact on polymerization of secondary reactions such as intramolecular cyclizations. For comparison purposes, FRP (conventional radical polymerization) of the same monomers is also considered.
Ionic Complexes of Polyacids and Cationic Surfactants
Authors: Tolentino Ainhoa , de Ilarduya Antxon Martínez , Alla Abdelilah , Muñoz‐Guerra Sebastián 
Published: November 2010

AbstractComb‐like ionic complexes were prepared from polyuronic acids (pectinic and alginic acids) and alkyltrimethylammonium surfactants bearing linear alkyl chains with 18, 20 and 22 carbon atoms. In the condensed state, these complexes were able to self‐assemble in ordered structures which were thermally stable up to ∼200 °C. The complexes were analysed by DSC and WAXS/SAXS and compared to their analogous made from poly(γ‐glutamic acid). They all adopt a biphasic layered structure in which the main chain and the alkyl side chain alternate with a nanometric periodicity. Alkyl side chains were partially crystallized in these complexes and they show reversible melting at temperatures within the 60‐80 °C range depending on the length of the polymethylene segment.
Polystyrene–Polyperfluorooctylethyl acrylate Diblock Copolymers: The Effect of Dilution of the Fluorinated Mesogenic Chains on Bulk and Surface Properties
Authors: Martinelli Elisa , Fantoni Chiara , Gallot Bernard , Glisenti Antonella , Galli Giancarlo 
Published: November 2010

AbstractSummary: Three smectic poly(styrene‐b‐perfluorooctylethyl acrylate) block copolymers (S‐b‐AF8) with different degrees of polymerization (n, m) of the relative blocks were synthesized by atom transfer radical polymerization (S, n = 25; AF8 m = 2, 6, 23). The mesophase structure and transition temperatures were investigated by DSC and WAXD. The block copolymer having the shortest fluorinated block was blended with a thermoplastic elastomer SEBS in different proportions, in order to look at the effect of a further dilution of the perfluorinated groups on non‐wetting properties. Thin films of the block copolymers as well as the blends exhibited large contact angles with both water and n‐hexadecane, which resulted in low solid surface tensions. XPS findings at different photoemission angles confirmed the effective surface segregation of the mesogenic chains of the fluorinated polymer block.
Elastomer‐Clay Nanocomposites: Effect of Elastomer Polarity
Authors: Susteric Zoran , Kos Tomaz 
Published: November 2010

AbstractDynamic mechanical properties of non‐polar and polar elastomer‐based nanocomposites with Montmorillonite clay are studied in order to ascertain differences caused by elastomer's polarity. Natural as non‐polar and polychloroprene as polar rubber are used to experimentally verify predictions based on different nature of elastomer‐clay interactions in the two cases. The properties foretold and elucidated in terms of van der Waals interactions in the non‐polar case and dipole‐dipole interactions in the polar case agree well with experiment, concurrently sustaining general depiction of these unusual nanocomposites.
Simulation of Chain Organization in Encapsulated Polymers
Authors: Cifra Peter , Bleha Tomas 
Published: November 2010

AbstractSummary: The dimensional and structural properties of polymers confined into a cavity are computed by the Monte Carlo method as a function of the chain stiffness. The reduction of the size ratio <R2 > / < R> close to 2, distinctive of compact spheres, is observed at squeezing of chains into a capsule. The plots of the static structure factor S(q) computed for stiff chains show characteristic humps attributed to the toroidal structure. The orientation correlation function is found to be a very sensitive indicator of the globule – toroid transition in encapsulated chains. Evidence is presented that the toroidal morphology is formed in stiff polymers when the capsule radius approaches the chain persistence length (D ∼ P).
Core Cross‐Linked Polymerized Micelles and Dendronized Nanoparticles
Authors: Zorin Ivan M. , Makarov Ivan A. , Ushkova Tatiana S. , Melnikov Alexander B. , Antonov Eugeny A. , Bilibin Alexander Yu. 
Published: November 2010

AbstractPolymerization of 11‐acryloylaminoundecanoic acid and its copolymerization with diacrylic monomers were performed under different conditions in micellar (Na‐salt in water) and non‐micellar states. The effect of conditions of the syntheses on molecular mass of the polymers and hydrodynamic characteristics of their macromolecules was studied. Ionic complexes of core‐cross‐linked polymerized micelles with different dendrons bearing polymerizable peripheral groups were obtained and their trial polymerizations were performed.
Phase Behaviour of Hydroxypropyl Cellulose/ Polyacrylamide Gels
Authors: Castro Carlos , Morales Ana , Koschella Andreas , Heinze Thomas 
Published: November 2010

AbstractSummary: Polysaccharide‐based materials have gained nowadays a great importance in many fields of industry, e.g., in the pharmaceutical industry. Some characteristics of such compounds are their non‐toxicity and the presence of a lower critical solution temperature (LCST) and/or an upper critical solution temperature (UCST). This work presents results on the synthesis and characterization of composites from hydroxypropyl cellulose (HPC) and polyacrylamide (PAAm). The ratio of HPC/PAAm was varied as well as the concentration of the crosslinker and the pH value of the reaction mixture. The compounds prepared were characterized by means of Fourier Transform Infrared spectroscopy (FTIR) and turbidity measurements. FTIR spectroscopy showed the presence of the main structural features of the precursors in the gels. The turbidity measurements of the gels in water showed the presence of a LCST in all samples. The LCST decreased when the quantity of HPC was increased in the gel and diminished also with increasing quantities of crosslinker and pH. The turbidity measurement showed the presence of an UCST when the concentration of the polymer was higher than 1% (w/w). This phenomenon is caused by the presence of the PAAm, which acted as precipitant and influenced over the entropy of the system and provoked phase separation.