bluuebunny/crossref_metadata_2025_split huggingface dataset:
Force spectroscopy of barnase–barstar single molecule interaction
Authors: Sekatskii S. K. , Favre M. , Dietler G. , Mikhailov A. G. , Klinov D. V. , Lukash S. V. , Deyev S. M. 
Published: April 2010

AbstractResults of the single molecule force spectroscopy study of specific interactions between ribonuclease barnase and its inhibitor barstar are presented. Experimental data obtained for the force loading rate ranging 2–70 nN/s are well approximated by a single straight line, from which the dissociation barrier of the width of 0.12 nm and height of 0.75–0.85×10−19 J can be inferred. The measured value of specific interaction does not depend on the NaCl concentration. This apparently contradicts the well‐known dependence of the binding energy of this pair on the salt concentration, but such a “contradiction” is explained by the insensitivity of the force spectroscopy data to the relatively long‐range electrostatic interaction. The latter essentially contributes to the value of barnase–barstar binding energy revealed by biochemical measurements, and it is exactly this electrostatic interaction which is influenced by the salt concentration. Copyright © 2010 John Wiley & Sons, Ltd.
Assessing 20th century climate–vegetation feedbacks of land‐use change and natural vegetation dynamics in a fully coupled vegetation–climate model
Authors: Strengers Bart J. , Müller Christoph , Schaeffer Michiel , Haarsma Reindert J. , Severijns Camiel , Gerten Dieter , Schaphoff Sibyll , van den Houdt Roy , Oostenrijk Rineke 
Published: April 2010

AbstractThis study describes the coupling of the dynamic global vegetation model (DGVM), Lund–Potsdam–Jena Model for managed land (LPJmL), with the general circulation model (GCM), Simplified Parameterizations primitivE Equation DYnamics model (SPEEDY), to study the feedbacks between land‐use change and natural vegetation dynamics and climate during the 20th century. We show that anthropogenic land‐use change had a stronger effect on climate than the natural vegetation's response to climate change (e.g. boreal greening). Changes in surface albedo are an important driver of the climate's response; but, especially in the (sub)tropics, changes in evapotranspiration and the corresponding changes in latent heat flux and cloud formation can be of equal importance in the opposite direction. Our study emphasizes that implementing dynamic vegetation into climate models is essential, especially at regional scales: the dynamic response of natural vegetation significantly alters the climate change that is driven by increased atmospheric greenhouse gas concentrations and anthropogenic land‐use change. Copyright © 2010 Royal Meteorological Society
More than symptom reduction: Changes in executive function over the course of PTSD treatment
Authors: Walter Kristen H. , Palmieri Patrick A. , Gunstad John 
Published: April 2010

AbstractPersons with posttraumatic stress disorder (PTSD) have neuropsychological impairments in multiple cognitive domains, though particularly in executive function. This exploratory study examined whether these cognitive impairments were alleviated following trauma‐focused treatment. Fifteen women underwent neuropsychological testing within a week of treatment onset and approximately 3 months later. Results suggest medium‐sized improvement in multiple aspects of executive function, including tests of cognitive flexibility/set‐shifting and organization/planning. If replicated in larger samples, such findings raise the possibility that treatment may alleviate neuropsychological impairment in persons with PTSD and thus reduce risk for poor outcome.
Smart Hydrogels Based on Modified Gum Arabic as a Potential Device for Magnetic Biomaterial
Authors: Paulino Alexandre T. , Guilherme Marcos R. , Mattoso Luiz H. C. , Tambourgi Elias B. 
Published: April 2010

AbstractBy means of a conventional cross‐linking/co‐polymerization reaction of modified gum arabic (M‐GA), acrylamide (AAm), and potassium acrylate (KAAc) in the presence of magnetite (Fe3O4) nanoparticles, a magnetic field‐sensitive M‐GA‐based hydrogel (smart hydrogel) was synthesized to investigate its potential as a magnetic biomaterial and as a intelligent hydrogel. Characterizations through FT‐IR, NMR, XRD, Mössbauer, SEM, and EDX inferred that the smart hydrogel was efficiently formed. Theoretically, the smart hydrogel obtained in this work may effectively be applied as biomaterial either on remote controlled release or tissue engineering or even in other areas of science and technology.magnified image
Microstructure and Indentation Behaviour of Polyhedral Oligomeric Silsesquioxanes‐Modified Thermoplastic Polyurethane Nanocomposites
Authors: Lach Ralf , Michler Goerg Hannes , Grellmann Wolfgang 
Published: April 2010

AbstractMorphological analyses of nanocomposites based on TPU and polyhedral oligomeric silsesquioxanes (POSS) was performed using different techniques (transmission electron microscopy, small‐ and wide‐angle X‐ray scattering, differential scanning calorimetry) as a function of molecular weight of poly(ethylene glycol) (PEG) and PEG/POSS mol ratio. A strong interdependence in crystallisation behaviour between the two (POSS and the soft segments of TPU) specified to be able to crystallise in TPU/POSS was found. The mechanical properties determined by using recording microindentation techniques at room temperature were significantly improved by POSS for two material formulations.magnified image
From a commodity to an experience: The moderating role of thematic positioning on congruity‐based product judgment
Authors: Noseworthy Theodore J. , Finlay Karen , Islam Towhidul 
Published: April 2010

AbstractResearch in positioning strategy suggests that a product schema, when presented in a moderately incongruent fashion, can evoke a greater degree of positive evaluation than if presented congruently with consumer expectations. This phenomenon has been coined the schema congruity effect. To date, one of the limitations of the phenomenon is that it has been applied almost exclusively to taxonomic stimuli, with little reference to thematic, eventlike stimuli. Two experiments verified that taxonomic and thematic product categories differ with respect to their unique characteristics. Consequently, despite successful replication of the schema congruity effect during taxonomic interpretation, when pushed thematically, the schema congruity effect failed to manifest. Furthermore, both experiments confirmed that, unlike taxonomic product categories that benefit from abstract and moderately incongruent positioning, thematic product categories benefit from concrete and congruent positioning. Implications for understanding the moderating role of thematic positioning on congruity‐based product evaluation as well as the differences between taxonomic and thematic stimuli are discussed. © 2010 Wiley Periodicals, Inc.
Aggregation‐Induced Emission in a Hyperbranched Poly(silylenevinylene) and Superamplification in Its Emission Quenching by Explosives
Authors: Lu Ping , Lam Jacky W. Y. , Liu Jianzhao , Jim Cathy K. W. , Yuan Wangzhang , Xie Ni , Zhong Yongchun , Hu Qin , Wong Kam Sing , Cheuk Kevin K. L. , Tang Ben Zhong 
Published: April 2010

AbstractA silicon‐containing hyperbranched polymer (hb‐P1/2) with σ*–π* conjugation was prepared in a good yield and high molecular weight by rhodium‐catalyzed alkyne polyhydrosilylation of 1,2‐bis(4‐ethynylphenyl)‐1,2‐diphenylethene (1) with tris(4‐dimethylsilylphenyl)amine (2). The polymer was thermally stable, losing merely 5% of its weight when heated to ≈445 °C. Whereas hb‐P1/2 was weakly luminescent when molecularly dissolved, it became highly emissive when supramolecularly aggregated, showing an aggregation‐induced emission (AIE) phenomenon. A superamplification effect was observed when the AIE nanoaggregates were used as fluorescent chemosensor for explosive detection: the quenching efficiency was greatly increased in a nonlinear fashion with increasing quencher concentration.magnified image
Synthesis of Prussian Blue Coordination Polymer Nanocubes via Confinement of the Polymerization Field Using Miniemulsion Periphery Polymerization (MEPP)
Authors: McHale Ronan , Ghasdian Negar , Liu Yibo , Wang Huihui , Miao Yuqing , Wang Xiaosong 
Published: April 2010

AbstractMiniemulsion periphery polymerization (MEPP) has been used for the synthesis of Prussian blue (PB) nanocubes. Pentacyano ferrate functionalized surfactant in combination with a co‐surfactant containing 4‐(dimethylamino)‐pyridine (DMAP) or OH end groups in lieu of ferrate functionality (EPE‐DMAP or EPE‐OH) were used to prepare a miniemulsion system comprising 20 wt.‐% toluene and 0.5 wt.‐% total surfactant. On addition of Fe3+ to the miniemulsion, metal coordination polymerization occurred with nanocubes generated when the ratio of EPE‐Fe:EPE‐DMAP (or EPE‐OH) was 60:40 (w/w). The resulting nanocubes are apparently amorphous. Particles with irregular shape have been observed on reacting EPE‐Fe and Fe3+ directly in water, thus suggesting that confinement of the polymerization field on the periphery of the miniemulsion droplets is a primary factor in the formation of cubic structures.magnified image
Electropolymerization of a Ruthenium(II) Bis(pyrazolyl)pyridine Complex to Form a Novel Ru‐Containing Conducting Metallopolymer
Authors: Zhu Xun Jin , Holliday Bradley J. 
Published: April 2010

AbstractA new derivative of 2,6‐bis(pyrazol‐1‐yl)pyridine (bpp) symmetrically substituted with 3,4‐ethylenedioxy‐thienyl (EDOT) substituent groups, and the corresponding ruthenium(II) complex was synthesized and characterized by NMR spectroscopy, elemental analysis, mass spectrometry, and single‐crystal X‐ray diffraction. A new linear conducting metallopolymer consisting of [Ru(bpp‐(EDOT)2)(terpy)]2+ fragments was deposited directly on to electrode surfaces as a transparent, deep red film by electrochemical coupling of the pendant EDOT moieties. XPS analysis reveals that the film has the expected structure consisting of monomer repeats without degradation or loss of metal ions. Additionally, the absorption spectrum of the polymer film shows a broad absorption range from 310 to 700 nm.magnified image
Restless legs syndrome: Evidence for nocturnal hypothalamic‐pituitary‐adrenal system activation
Authors: Schilling Claudia , Schredl Michael , Strobl Philipp , Deuschle Michael 
Published: April 2010

AbstractEpidemiological studies consistently point to a relationship between restless legs syndrome (RLS) and cardiovascular disease. The mechanism underlying this association is unclear. Activation of the hypothalamic‐pituitary‐adrenal (HPA) system has been shown to contribute to the metabolic syndrome and an enhanced cardiovascular risk. We investigated cortisol levels as an indicator of HPA system activity in RLS during the nighttime, when RLS symptoms are at their maximum. We assessed nocturnal urinary cortisol excretion in 73 patients with RLS and 34 healthy controls, controlling for age and gender. Urine sampling was paralleled by polysomnographic recordings. We found significantly enhanced nocturnal cortisol excretion in RLS, demonstrating nocturnal HPA system overactivity in RLS. HPA system overactivity is a possible mechanism contributing to the enhanced load of cardiovascular disease in RLS patients. Nocturnal cortisol release showed weak correlations with some polysomnographic parameters of disturbed sleep, making a potential contribution of RLS‐induced sleep disruption to HPA system activation conceivable. © 2010 Movement Disorder Society
Synthesis and Characterization of Benzyl Methacrylate/Styrene Random Copolymers Prepared by NMP
Authors: Zhang Chi , Lessard Benoit , Maric Milan 
Published: April 2010

AbstractBzMA/styrene random copolymers were synthesized in bulk (molar feed compositions fBzMA,0 = 10–90 mol‐%) at 90 °C by NMP with about 10% free SG1 relative to BlocBuilder initiator. Reactivity ratios (rBzMA = 0.86 ± 0.36, rstyrene = 0.27 ± 0.14) were comparable to those reported by conventional radical polymerization. Linear $\overline M _{\rm n} $ increase with conversion was observed up to ∼50% conversion, and all copolymers had low $\overline M _{\rm w} /\overline M _{\rm n} $ = 1.2–1.4. The $\left\langle {k_{\rm p} } \right\rangle \left\langle K \right\rangle $ ($\left\langle {k_{\rm p} } \right\rangle $ = average propagation rate constant and $\left\langle K \right\rangle $ = average equilibrium constant) exponentially increased with increasing fBzMA,0. Chain extensions with styrene at 110 °C initiated by BzMA/styrene copolymers made with fBzMA,0 <80 mol‐% were highly living while macroinitatiors with fBzMA,0 >90 mol‐% were not, based on GPC and 31P NMR results.magnified image
Mechanical properties of glass bead‐ and wollastonite‐filled isotactic‐polypropylene composites modified with thermoplastic elastomers
Authors: Balkan Onur , Demirer Halil 
Published: April 2010

AbstractMechanical properties of the isotactic‐polypropylene/glass bead (iPP/GB) and iPP/wollastonite (iPP/W) composites modified with thermoplastic elastomers, the poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) copolymer (SEBS) and corresponding block copolymer grafted with maleic anhydride (SEBS‐g‐MA), were investigated. An increase in toughness of iPP with the elastomers was associated with a decrease in rigidity and strength. Mechanical performance of iPP increased more with acicular W than with spherical GB due to reinforcing effect of W. Comparing the (iPP/GB)/SEBS and (iPP/W)/SEBS composites having the separate microstructure, strength and toughness values of the iPP/GB and iPP/W composites increased more with SEBS‐g‐MA at the expense of rigidity due to the core‐shell microstructure with strong interfacial adhesion. Moreover, the iPP/W composite exhibited superior mechanical performance with 2.5 and 5 vol% of SEBS‐g‐MA because of a positive synergy between the core‐shell microstructure and reinforcing effect of acicular W. The extended models revealed that the elastomer and filler particles in the (iPP/GB)/SEBS and (iPP/W)/SEBS composites acted individually due to the separate microstructure. However, the rigid GB and W particles encapsulated with the thick elastomer interlayer (R0/R1 = 0.91) in the (iPP/GB)/SEBS‐g‐MA and (iPP/W)/SEBS‐g‐MA composites acted like neither big elastomer particles nor like individual rigid particles, inferring more complicated failure mechanisms in the core‐shell composites. POLYM. COMPOS., 31:1285–1308, 2010. © 2010 Society of Plastics Engineers
Twin anemia polycythemia sequence from a prenatal perspective
Authors: Gucciardo Léonardo , Lewi Liesbeth , Vaast Pascal , Debska Marzena , De Catte Luc , Van Mieghem Tim , Done Elisa , Devlieger Roland , Deprest Jan 
Published: April 2010

AbstractObjectivesTo describe the prevalence, management and outcome of spontaneous twin anemia polycythemia sequence (TAPS) diagnosed in the prenatal period.MethodRetrospective analysis of 142 consecutive monochorionic twin pregnancies not diagnosed with twin to twin transfusion syndrome. TAPS cases were identified based on the presence of discordant middle cerebral artery peak systolic velocity (MCA‐PSV) measurements and signs suggestive of a chronic intertwin transfusion imbalance: either an elevated reticulocyte count in the anemic twin or the presence of few small unidirectional anastomoses during fetoscopy or at postnatal placental examination.ResultsThree cases were identified, giving an estimated prevalence of 2%. Prenatal interventions were tailored to the characteristics of each case and consisted of intrauterine transfusion and interruption of the shared circulation by cord coagulation or laser separation.ConclusionIn monochorionic twin pregnancies, TAPS is an uncommon prenatal finding. Nonetheless, its incidence seems high enough to recommend screening for this disease by MCA‐PSV measurements. Copyright © 2010 John Wiley & Sons, Ltd.
Uptake of prenatal diagnostic testing and the effectiveness of prenatal screening for Down syndrome
Authors: Jaques Alice M. , Collins Veronica R. , Muggli Evelyne E. , Amor David J. , Francis Ivan , Sheffield Leslie J. , Halliday Jane L. 
Published: April 2010

AbstractObjectivesTo map prenatal screening and diagnostic testing pathways in Victorian pregnant women during 2003 to 2004; measure the impact of prenatal diagnostic testing uptake on the effectiveness of prenatal screening for Down syndrome; and assess factors influencing uptake of diagnostic testing following screening.MethodsState‐wide data collections of prenatal screening and diagnostic tests were linked to all Victorian births and pregnancy terminations for birth defects.ResultsOverall, 52% of women had a prenatal test (65 692/126 305); screening (44.9%), diagnostic testing (3.9%), or both (3.2%). Uptake of diagnostic testing was 71.4% (2390/3349) after an increased risk screen result, and 2.5% (1381/54 286) after a low risk result. Variation in uptake of diagnostic testing reduced the effectiveness of the screening program by 11.2%: from 87.4% (sensitivity − 125/143) to 76.2% (prenatal diagnoses of Down syndrome − 109/143). In both the increased and low risk groups, uptake was influenced by absolute numerical risk, as well as by the change in numerical risk from a priori risk.ConclusionsThis comprehensive follow‐up demonstrates clearly that numerical risk is being used to aid in decision making about confirmatory diagnostic testing. Collectively, these fundamental individual decisions will impact on the overall effectiveness of screening programmes for Down syndrome. Copyright © 2010 John Wiley & Sons, Ltd.
Three‐dimensional simulation on multilayer parison shape at pinch‐off stage in extrusion blow molding
Authors: Fukuzawa Youhei , Tanoue Shuichi , Iemoto Yoshiyuki , Kawachi Ryuichi , Tomiyama Hideki 
Published: April 2010

AbstractWe tried to predict the multilayer parison shape at pinch‐off stage in extrusion blow molding by nonisothermal and purely viscous non‐Newtonian flow simulation using the finite element method (FEM). We assumed the parison deformation as a flow problem. The Carreau model was used as the constitutive equation and FEM was used for calculation method. Multilayer parison used in this simulation was composed of high‐density polyethylene (HDPE) as inner and outer layers and low‐density polyethylene (LDPE) of which viscosity is five times lower than HDPE as a middle layer. We discussed multilayer parison shape in pinch‐off region. The results obtained are as follows; the parison shape of each layer was clearly visible in the pinch‐off during the mold closing. In addition, the distribution of parison thickness ratios for each layer was located for a large deformation near the pinch‐off region. The melt viscosity for each layer has an influence on the melt flow in the pinch‐off region. In a comparison with an experimental data of parison thickness ratios, the simulation results are larger than the experimental data. These simulation results obtained are in good agreement with the experimental data in consideration of the standard deviations. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Polymerization of ethylene by (α‐Diimine) nickel catalyst and statistical analysis of the effects of reaction conditions
Authors: Ferreira Luis Carlos , Melo Priamo Albuquerque , Crossetti Geraldo Lopes , Galland Griselda Barrera , Nele Marcio , Pinto José Carlos 
Published: April 2010

AbstractThis article regards the ethylene polymerization catalyzed by a nickel catalyst and activated by ethylaluminum sesquichloride (EASC). The effects of the reaction conditions [polymerization temperature, cocatalyst (EASC) concentration, and ethylene concentration] on the average molecular weights of the final polymers and reaction yields were evaluated with the help of empirical statistical models. It is shown that reaction temperature and cocatalyst (EASC) concentration exert the most important effects on average molecular weights and catalyst activity. The polydispersities of the obtained polyethylenes are larger than the polydispersities of polyethylenes obtained with typical Brookhart catalysts. The analysis of polymer branching frequencies shows new types of short branching and significant amounts of long branches, which may explain the relatively large polydispersities of the obtained polymer samples. POLYM. ENG. SCI., 50:1797–1808, 2010. © 2010 Society of Plastics Engineers
Polymer electrolyte membranes based on p‐toluenesulfonic acid doped poly(1‐vinyl‐1,2,4‐triazole): Synthesis, thermal and proton conductivity properties
Authors: Özden Şehmus , Çeli̇k Sevi̇m Ünügür , Bozkurt Ayhan 
Published: April 2010

AbstractThroughout this work, the synthesis, thermal as well as proton conducting properties of acid doped heterocyclic polymer were studied under anhydrous conditions. In this context, poly(1‐vinyl‐1,2,4‐triazole), PVTri was produced by free radical polymerization of 1‐vinyl‐1,2,4‐triazole with a high yield. The structure of the homopolymer was proved by FTIR and solid state 13C CP‐MAS NMR spectroscopy. The polymer was doped with p‐toluenesulfonic acid at various molar ratios, x = 0.5, 1, 1.5, 2, with respect to polymer repeating unit. The proton transfer from p‐toluenesulfonic acid to the triazole rings was proved with FTIR spectroscopy. Thermogravimetry analysis showed that the samples are thermally stable up to ∼250 °C. Differential scanning calorimetry results illustrated that the materials are homogeneous and the dopant strongly affects the glass transition temperature of the host polymer. Cyclic voltammetry results showed that the electrochemical stability domain extends over 3 V. The proton conductivity of these materials increased with dopant concentration and the temperature. Charge transport relaxation times were derived via complex electrical modulus formalism (M*). The temperature dependence of conductivity relaxation times showed that the proton conductivity occurs via structure diffusion. In the anhydrous state, the proton conductivity of PVTri1PTSA and PVTri2PTSA was measured as 8 × 10−4 S/cm at 150 °C and 0.012 S/cm at 110 °C, respectively. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1016–1021, 2010
Poly(bis‐2,2,2‐trifluoroethoxymethyl oxetane): Multiple crystal phases, crystallization‐induced surface topological complexity and enhanced hydrophobicity
Authors: Zheng Ying , Zhang Wei , Gupta Murari , Kankanala Spandana , Marks Carolyn , Carpenter Everett , Carroll Kyler , Wynne Kenneth J. 
Published: April 2010

AbstractSemicrystalline poly(bis‐trifluoroethoxymethyl)oxetane, P(B‐3FOx), was prepared by cationic ring‐opening polymerization at −5 °C with Mn up to 21 kDa. Differences in cooling rates from the melt have substantial effects on crystal phase, percent crystallinity, surface topography, and wetting behavior. DSC and WAXD show that cooling from the melt at slow rates (<5 °C/min) gives α‐P(B‐3FOx) with ΔHf = 22–27 J/g. Quenching from the melt results in β‐P(B‐3FOx) for which a mesophase structure is suggested. β‐P(B‐3FOx) melts at 53 °C followed by recrystallization to α‐P(B‐3FOx). Solution casting from THF results in third phase, γ‐P(B‐3FOx). TM‐AFM and SEM imaging for α‐P(B‐3FOx) showed that cold crystallization at 25 °C brought about increased crystallinity and surface topologies characterized by sharp asperities and lath‐shaped crystals. Spontaneous surface roughening of α‐P(B‐3FOx) results in a discontinuous three‐phase contact line with water and an increase in water sessile drop contact angle from 106° to 136°. The ∼30° increase in water contact angle was attributed primarily to a topological change from a relatively smooth surface (Wenzel state) to an asperity‐rich surface yielding a discontinuous three‐phase contact line (composite of Wenzel and Cassie‐Baxter state). The oleophobicity for this polymer, which contains only a single CF3 end group on each side chain, compares favorably with more highly fluorinated acrylates. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1022–1034, 2010