bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of surface modification on the structure and properties of a zinc oxide‐filled poly(ethylene terephthalate)
Authors: Gao Wei , Zhou Bing , Liu Yanhua , Ma Xiaoyu , Liu Yan , Wang Zichen , Zhu Yanchao 
Published: August 2012

AbstractHydrophobic zinc oxide (ZnO) nanoparticles were successfully prepared by a one‐step precipitation reaction in an aqueous solution of zinc sulfate and sodium hydroxide with stearic acid as the modifying agent. Poly(ethylene terephthalate) (PET)/ZnO nanocomposites were prepared by further in situ polymerization of purified terephthalic acid, ethylene glycol and the ZnO nanoparticles. The surface modification of ZnO and the microstructure and properties of the nanocomposites were investigated using relative contact angle measurements, Fourier transform infrared spectroscopy, X‐ray diffraction, transmission and scanning electron microscopies, thermogravimetric analysis and differential scanning calorimetry. Measurements of relative contact angle indicated that the surface‐treated ZnO was hydrophobic. Compared to the nanocomposite filled with unmodified ZnO, a significant improvement in thermal stability and crystallinity was observed with the addition of 2 wt% surface‐treated ZnO. The experimental results also suggested that the properties of the nanocomposites were correlated with the dispersion of ZnO in PET and the interfacial interactions between ZnO and PET matrix. © 2012 Society of Chemical Industry
Synthesis and characterization of poly[(1‐vinyl‐1,2,4‐triazole)‐co‐(monomer with carboxylic acid group(s))] and determination of monomer reactivity ratios: I. Acrylic acid
Authors: Kılıç Esra , Bayramgil Nursel Pekel 
Published: August 2012

AbstractCopolymers of 1‐vinyl‐1,2,4‐triazole (VTAz) and acrylic acid (AA) having different mole ratios were synthesized using free radical‐initiated solution polymerization in dimethylformamide at 70 °C with α,α′‐azobisisobutyronitrile as initiator in nitrogen atmosphere. The compositions of the synthesized copolymers for a wide range of monomer feeds were determined using Fourier transform infrared (FTIR) spectroscopy through recorded absorption bands for VTAz (1510 cm−1, CN (triazole ring) stretching mode) and AA (1710 cm−1, CO stretching mode) units. The structures of the copolymers were characterized using FTIR and 1H NMR spectroscopy. The copolymer compositions were also determined from 1H NMR analysis following proton signals of carboxyl group at 11.8–12.5 ppm of AA and of triazole ring at 7.5–8.1 ppm of VTAz. Monomer reactivity ratios for the VTAz‐AA pair were estimated using linear methods, i.e. Fineman–Ross (FR) and Kelen–Tüdös (KT). From FTIR evaluation, monomer reactivity ratios were calculated as r1 = 0.404 and r2 = 1.496 using the FR method and r1 = 0.418 and r2 = 1.559 using the KT method. These values were found to be very close to those obtained from NMR evaluation. The two cases r1r2 < 1 and r1 < r2 indicated the random distribution of the monomers in the final copolymers and the presence of a greater amount of AA units in the copolymer than in the feed, respectively. The observed relatively high activity of complexed growing radical‐AA• … VTAz was explained by the effect of complex formation between carbonyl groups and triazole fragments in chain growth reactions. Thermal behaviours of copolymers with various compositions were investigated using thermogravimetric and differential scanning calorimetric analyses. It was observed that thermal stabilities and glass transition temperatures of the copolymers increased resulting from complex formation between acid and triazole units. © 2012 Society of Chemical Industry
Synthesis of graft copolymers onto styrenic polymer backbone via “grafting from” raft process
Authors: Rajendran Prakash Babu , Raghavachari Dhamodharan 
Published: August 2012

AbstractA new synthetic methodology is developed for preparing graft copolymers via RAFT polymerization method by the “R group approach” onto styrenic polymers. In this approach, latent sites of the styrenic polymer was brominated first and then converted into macro‐RAFT agents with pyrazole and thio dodecyl as the Z groups. This was used to synthesize graft copolymer such as polystyrene‐graft‐polymethyl methacrylate (PS‐g‐PMMA), polystyrene‐graft‐poly(isobornyl acrylate), polystyrene‐graft‐poly[2‐(acetoacetoxy)ethyl methacrylate] (PS‐g‐PAEMA), and poly(para‐methoxystyrene)‐graft‐polystyrene (P(p‐MS)‐g‐PS). The polymers are characterized by gel permeation chromatography, 1H NMR, IR, and atomic force microscopy (AFM). The morphology of PS‐g‐PMMA in THF was investigated using AFM and island‐like features were noticed. The AFM studies of the PS‐g‐PAEMA graft copolymers revealed the formation of globules and ribbon‐like morphological features. The PS‐g‐PAEMA graft copolymers form complex with Fe(III) in dimethylformamide and the AFM studies suggest the formation of globular superstructures. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
A Solution‐processible, n‐dopable polypyrrole derivative
Authors: Camurlu Pinar , Eren Esin , Gültekin Cemil 
Published: August 2012

AbstractIn this study, soluble, n‐dopable, florescent, electrochromic polypyrrole derivative was synthesized through both chemical and electrochemical polymerization of 2‐[6‐(1H‐pyrrol‐1‐yl)hexyl]‐1H‐benzo[de]isoquinoline‐1,3(2H)‐dione (PyNI). The polymer synthesized through chemical polymerization had PL emission maxima at 471 and 543 nm and exhibited two redox couples at E1/2,p = −1.48 V and E1/2,p = 1.12 V due to n‐type and p‐type doping, respectively. Electrochromic properties of electrochemically synthesized poly(PyNI) (PPyNI) were investigated via spectroelectrochemistry, kinetic studies, coloration efficiency, and colorimetry measurements. The optical band gap of PPyNI was calculated as 2.99 and 2.37 eV. Spectroelectrochemistry analysis of PPyNI reflected electronic transitions at 330–418 nm and 704 nm due to π–π* transition and charge carrier band formation, respectively. The polymer exhibited a switching time of 1.63 s and an optical contrast of 33.37%. Furthermore, dual‐type, complementary‐colored polymer electrochromic device in ITO/PPyNI/PEDOT/ITO configuration was assembled and characterized. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Quantifying the elasticity and viscosity of geometrically confined polymer films via thermal wrinkling
Authors: Chan Edwin P. , Lin Qinghuang , Stafford Christopher M. 
Published: August 2012

AbstractWe apply thermal wrinkling, which is a surface instability that occurs during thermal annealing of polymer films geometrically confined by a rigid substrate and a flexible superstrate, to study the elasticity and viscosity of chemically crosslinked polymer systems. Specifically, we study the thermal wrinkling of aluminum‐capped polyhydroxystyrene films with different extent of chemical crosslinking and find that that the rate of change of the wrinkling wavelength with annealing time and temperature has unique relationships with the elasticity and viscosity of the polymer network. With the aid of analytical expressions that relate the time‐ and temperature‐dependent evolution of the wrinkle wavelength to the elasticity and viscosity, we are able to quantify the elastic modulus and shear viscosity of geometrically confined polymer thin films as a function of the degree of crosslinking. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Click coupled graphene for fabrication of high‐performance polymer nanocomposites
Authors: Yadav Santosh Kumar , Yoo Hye Jin , Cho Jae Whan 
Published: August 2012

AbstractAn effective technique of using click coupled graphene to obtain high‐performance polymer nanocomposites is presented. Poly(ε‐caprolactone) (PCL)‐click coupled graphene sheet (GS) reinforcing fillers are synthesized by the covalent functionalization of graphene oxide with PCL, and subsequently the PCL‐GS as a reinforcing filler was incorporated into a shape memory polyurethane matrix by solution casting. The PCL‐click coupled GS has shown excellent interaction with the polyurethane matrix, and as a consequence, the mechanical properties, thermal stability, thermal conductivity, and thermo‐responsive shape memory properties of the resulting nanocomposite films could be enhanced remarkably. In particular, for polyurethane nanocomposites incorporated with 2% PCL‐GS, the breaking stress, Young's modulus, elongation‐at‐break, and thermal stability have been improved by 109%, 158%, 28%, and 71 °C, respectively. This click coupling protocol offers the possibility to fully combine the extraordinary performance of GSs with the properties of polyurethane. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013
Plasma and urine proteomic profiles in childhood idiopathic nephrotic syndrome
Authors: Andersen René Frydensbjerg , Palmfeldt Johan , Jespersen Bente , Gregersen Niels , Rittig Søren 
Published: August 2012

PurposeIdiopathic nephrotic syndrome (NS) is characterized by proteinuria, edema, and hypoalbuminemia. The aim of the study was to identify differentially expressed proteins in urine and plasma during NS compared with remission.Experimental designPlasma and urine samples were collected during NS and at remission. Proteomic profiling was performed by iTRAQ labeling followed by nano‐LC‐MS/MS to yield data on relative protein amounts. Protein validation was performed by ELISA.ResultsA total of 388 and 425 proteins were detected in plasma and urine, respectively. In total, 18 plasma and 38 urinary proteins were significantly altered (p <0.05). E‐cadherin was one of the proteins with reduced urinary concentration during NS, a finding validated by ELISA. The slit diaphragm protein P‐cadherin was identified by nano‐LC‐MS/MS and shown to be reduced in urine during NS by ELISA.Conclusions and clinical relevanceThe present study identified more than 50 differentially altered proteins comparing NS with remission. Several proteins were found to be linked to the major clinical symptoms of NS, and further studies must elucidate if P‐cadherin is involved in proteinuria during NS, and if low urinary E‐cadherin level is linked to altered epithelial cell to cell contact in the distal part of the nephron.
Serum proteome profiling of pancreatitis using recombinant antibody microarrays reveals disease‐associated biomarker signatures
Authors: Sandström Anna , Andersson Roland , Segersvärd Ralf , Löhr Mattias , Borrebaeck Carl A. K. , Wingren Christer 
Published: August 2012

PurposePancreatitis is an inflammatory state of the pancreas, for which high‐performing serological biomarkers are lacking. The aim of the present study was to evaluate the use of affinity proteomics for identifying potential markers of disease and stratifying pancreatitis subtypes.Experimental designHigh‐content, recombinant antibody microarrays were applied for serum protein expression profiling of 113 serum samples from patients with chronic, acute, and autoimmune pancreatitis, as well as healthy controls. The sample groups were compared using supervised classification based on support vector machine analysis.ResultsThis discovery study showed that pancreatitis subtypes could be discriminated with high accuracy. Using unfiltered data, the individual subtypes, as well as the combined pancreatitis cohort, were distinguished from healthy controls with high AUC values (0.96–1.00). Moreover, characteristic protein patterns and AUC values in the range of 0.69–0.95 were observed for the individual pancreatitis entities when compared to each other, and to all other samples combined.Conclusions and clinical relevanceThis study demonstrated the potential of the antibody microarray approach for stratification of pancreatitis. Distinct candidate multiplex serum biomarker signatures for chronic, acute, and autoimmune pancreatitis were defined, which could enhance our fundamental knowledge of the underlying molecular mechanisms, and potentially lead to improved diagnosis.
Augmented generation of protein fragments during wakefulness as the molecular cause of sleep: a hypothesis
Authors: Varshavsky Alexander 
Published: August 2012

AbstractDespite extensive understanding of sleep regulation, the molecular‐level cause and function of sleep are unknown. I suggest that they originate in individual neurons and stem from increased production of protein fragments during wakefulness. These fragments are transient parts of protein complexes in which the fragments were generated. Neuronal Ca2+ fluxes are higher during wakefulness than during sleep. Subunits of transmembrane channels and other proteins are cleaved by Ca2+‐activated calpains and by other nonprocessive proteases, including caspases and secretases. In the proposed concept, termed the fragment generation (FG) hypothesis, sleep is a state during which the production of fragments is decreased (owing to lower Ca2+ transients) while fragment‐destroying pathways are upregulated. These changes facilitate the elimination of fragments and the remodeling of protein complexes in which the fragments resided. The FG hypothesis posits that a proteolytic cleavage, which produces two fragments, can have both deleterious effects and fitness‐increasing functions. This (previously not considered) dichotomy can explain both the conservation of cleavage sites in proteins and the evolutionary persistence of sleep, because sleep would counteract deleterious aspects of protein fragments. The FG hypothesis leads to new explanations of sleep phenomena, including a longer sleep after sleep deprivation. Studies in the 1970s showed that ethanol‐induced sleep in mice can be strikingly prolonged by intracerebroventricular injections of either Ca2+ alone or Ca2+ and its ionophore (Erickson et al., Science 1978;199:1219–1221; Harris, Pharmacol Biochem Behav 1979;10:527–534; Erickson et al., Pharmacol Biochem Behav 1980;12:651–656). These results, which were never interpreted in connection to protein fragments or the function of sleep, may be accounted for by the FG hypothesis about molecular causation of sleep.
Comparison of the structures and stabilities of coiled‐coil proteins containing hexafluoroleucine and t‐butylalanine provides insight into the stabilizing effects of highly fluorinated amino acid side‐chains
Authors: Buer Benjamin C. , Meagher Jennifer L. , Stuckey Jeanne A. , Marsh E. Neil G. 
Published: August 2012

AbstractHighly fluorinated analogs of hydrophobic amino acids are well known to increase the stability of proteins toward thermal unfolding and chemical denaturation, but there is very little data on the structural consequences of fluorination. We have determined the structures and folding energies of three variants of a de novo designed 4‐helix bundle protein whose hydrophobic cores contain either hexafluoroleucine (hFLeu) or t‐butylalanine (tBAla). Although the buried hydrophobic surface area is the same for all three proteins, the incorporation of tBAla causes a rearrangement of the core packing, resulting in the formation of a destabilizing hydrophobic cavity at the center of the protein. In contrast, incorporation of hFLeu, causes no changes in core packing with respect to the structure of the nonfluorinated parent protein which contains only leucine in the core. These results support the idea that fluorinated residues are especially effective at stabilizing proteins because they closely mimic the shape of the natural residues they replace while increasing buried hydrophobic surface area.
The story of a new insecticidal chemistry class: the diamides
Authors: Jeanguenat André 
Published: August 2012

AbstractThis paper describes the story of the invention of the diamides, a novel chemical class of insecticides. It starts with the pioneering work by Nihon Nohyaku researchers, who developed a herbicide lead with weak insecticidal activity to flubendiamide, a highly potent lepidoptericide. The journey continues with Nissan's isoxazolines and the invention of the anthranilamides by DuPont, culminating in the discovery of the blockbuster chlorantraniliprole and its analogue cyantraniliprole. The next steps are Syngenta's sulfoximines and bicyclic anthranilamides, Ishihara Sangyo Kaisha's cyclopropylamides, Sumitomo's hydrazides, Bayer's pyrazoles and tetrazoles, BASF's sulfoximines and more recent contributions from Chinese agrochemical companies and academic institutions. The diamides affect calcium homeostasis by binding to ryanodine receptors and releasing calcium from the intracellular stores. Investigations at Nihon Nohyaku, DuPont and Bayer on the action of the diamides on ryanodine receptors will be briefly reported.
Design, synthesis and structure–activity relationship of novel insecticidal dichloro‐allyloxy‐phenol derivatives containing substituted pyrazol‐3‐ols
Authors: Li Miao , Liu Chang‐Ling , Zhang Jing , Wu Qiao , Hao Shu‐Lin , Song Yu‐quan 
Published: August 2012

AbstractBACKGROUNDPyridalyl, consisting of dicholoro‐allyoxy‐phenol moiety, is a novel class of insecticide showing extraordinary activities against various lepidopterous and thysanopterous pests on cotton and vegetables. To discover further novel insecticides, a series of new dichloro‐allyloxy‐phenol derivatives containing substituted pyrazol‐3‐ol moieties were designed and synthesised via the intermediate derivatisation method.RESULTSThe target compounds were characterised by 1H NMR, IR, MS and elemental analysis. Bioassays indicated that some of these compounds exhibited good insecticidal activities against diamondback moth (Plutella xylostella) at 6.25 mg L−1. The structure–activity relationship is discussed.CONCLUSIONThe present work demonstrates that dichloro‐allyloxy‐phenol derivatives with substituted phenylpyrazole moieties can be used as lead compounds to develop further novel insecticides.© 2012 Society of Chemical Industry
Broadband non‐selective excitation of plutonium isotopes for isotope ratio measurements in resonance ionization mass spectrometry: a theoretical study
Authors: Sankari M. 
Published: August 2012

RATIONALEMaking isotope ratio measurements with minimum isotope bias has always been a challenging task to mass spectrometrists, especially for the specific case of plutonium, owing to the strategic importance of the element. In order to use resonance ionization mass spectrometry (RIMS) as a tool for isotope ratio measurements, optimization of the various laser parameters and other atomic and system parameters is critical to minimize isotopic biases.METHODSBroadband simultaneous non‐selective excitation of the isotopes of plutonium in the triple resonance excitation scheme with λ1 = 420.77 nm, λ2 = 847.28 nm, and λ3 = 767.53 nm based on density matrix formalism has been theoretically computed for the determination of isotope ratios. The effects of the various laser parameters and other factors such as the atomization temperature and the dimensions of the atomic beam on the estimation of isotope ratios were studied. The effects of Doppler broadening, and time‐dependent excitation parameters such as Rabi frequencies, ionization rate and the effect of non‐Lorenztian lineshape have all been incorporated.RESULTSThe average laser powers and bandwidths for the three‐excitation steps were evaluated for non‐selective excitation. The laser intensity required to saturate the three‐excitation steps were studied. The two‐dimensional lineshape contour and its features were investigated, while the reversal of peak asymmetry of two‐step and two‐photon excitation peaks under these conditions is discussed. Optimized powers for the non‐selective ionization of the three transitions were calculated as 545 mW, 150 mW and 545 mW and the laser bandwidth for all the three steps was ~20 GHz.CONCLUSIONSThe isotopic bias between the resonant and off‐resonant isotope under the optimized conditions was no more than 9%, which is better than an earlier reported value. These optimized laser power and bandwidth conditions are better than in the earlier experimental work since these comprehensive calculations yield simultaneous and much more accurate isotope ratios than those in the sequential and less accurate determination reported earlier. Application of these theoretical calculations to minimize the isotopic biases under these conditions for the rapid, efficient and accurate isotope ratio measurements using RIMS has been outlined. Copyright © 2012 John Wiley & Sons, Ltd.
Comparing Solar Water Heater Popularization Policies in China, Israel and Australia: The Roles of Governments in Adopting Green Innovations
Authors: Li Wei , Rubin Tzameret H. , Onyina Paul A. 
Published: August 2012

ABSTRACTStudying the roles of governments in adopting green innovations is significant for analysing the transition to a more sustainable energy system. This article presents a comparative study of policies for popularizing domestic solar water heaters in three countries: China, Israel and Australia. Expanding the analysis beyond the economics of innovation, it demonstrates the institutional dimension of green technology deployment in these three countries. By examining the diverging roles of governments in facilitating green technology adoption in existing social routines and practices, it finds that governments' motivations, support and implementation mechanisms are remarkably different in these three countries. In particular, the paper argues that solar water heater popularization has been distinguished as a business opportunity in China, energy security in Israel and environmental responsibility in Australia. In addition, the institutional settings have a real impact on governments' roles in adopting green innovations, in terms of the policy instruments chosen and implementation mechanisms. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
A practical model‐based statistical approach for generating functional test cases: application in the automotive industry
Authors: Awedikian Roy , Yannou Bernard 
Published: August 2012

SUMMARYWith the growing complexity of industrial software applications, industrials are looking for efficient and practical methods to validate the software. This paper develops a model‐based statistical testing approach that automatically generates online and offline test cases for embedded software. It discusses an integrated framework that combines solutions for three major software testing research questions: (i) how to select test inputs; (ii) how to predict the expected results of a test; and (iii) when to stop testing software. The automatic selection of test inputs is based on a stochastic test model that accounts for the main particularity of embedded software: time sensitivity. Software test practitioners may design one or more test models when they generate random, user‐oriented, or fault‐oriented test inputs. A formal framework integrating existing and appropriate specification techniques was developed for the design of automated test oracles (executable software specifications) and the formal measurement of functional coverage. The decision to stop testing software is based on both test coverage objectives and cost constraints. This approach was tested on two representative case studies from the automotive industry. The experiment was performed at unit testing level in a simulated environment on a host personal computer (automatic test execution). The two software functionalities tested had previously been unit tested and validated using the test design approach conventionally used in the industry. Applying the proposed model‐based statistical testing approach to these two case studies, we obtained significant improvements in performing functional unit testing in a real and complex industrial context: more bugs were detected earlier and in a shorter time. Copyright © 2012 John Wiley & Sons, Ltd.