bluuebunny/crossref_metadata_2025_split huggingface dataset:
Processing, structure, and properties of multiwalled carbon nanotube/poly(hydroxybutyrate‐co‐valerate) biopolymer nanocomposites
Authors: Ma Yanxuan , Zheng Yudong , Wei Guangye , Song Wenhui , Hu Te , Yang Huai , Xue Rundong 
Published: February 2012

AbstractBiopolymer nanocomposites of carbon nanotubes (CNTs) which reinforced poly(hydroxybutyrate‐co‐valerate) (PHBV) were developed. Multiwalled carbon nanotubes were modified by an acid oxidation treatment (A‐MWCNTs) to improve their dispersal in the polymer. The thermal properties, crystallization behavior, microstructure, and cross‐sectional morphology of the composites were investigated. Their mechanical properties and surface contact angles were tested. The cytotoxicity of the composites to murine fibroblast L929 cells was also evaluated. The results show that A‐MWCNTs are homogeneously dispersed in PHBV which demonstrate strong heterogeneous nucleation on the dynamics and kinetics of crystallization of PHBV. With the addition of A‐MWCNTs, the crystallization temperature, heat of crystallization, and thermal stability of the composites increase. Consequently, the mechanical properties of the composites have been substantially improved. The composites become hydrophilic and have no obvious toxicity to the murine fibroblast L929 cells when the content of A‐MWCNTs is below 1.5 wt %. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Removal of toxic metal ions by using composite cation‐exchange material
Authors: Nabi S. A. , Bushra Rani , Shahadat Mohammad 
Published: February 2012

AbstractPolyanilinezirconium(IV) arsenate composite cation exchange material was synthesized under different experimental conditions by the incorporation of polyaniline into the matrices of inorganic precipitate (zirconium(IV)arsenate). The experimental parameters such as concentration, mixing volume ratio, and pH were established for the synthesis of the material. Ion‐exchange material that was synthesized at pH 1.0 showed an ion exchange capacity of 1.33 meq g−1 for Na+ ions. The composite material exhibits improved ion‐exchange capacity along with chemical and thermal stability. The exchanger was characterized based on FTIR, TGA, XRD, and SEM analysis. The X‐ray diffraction study shows semi‐crystalline nature of the material. The distribution coefficient studies (Kd) of metal ions on the material were performed in diverse solvent systems. Based on Kd values the material was found to be selective for Pb(II) and Hg(II) ions. Some analytically important binary separations of metal ions in synthetic mixtures viz. Ba2+‐Pb2+, Pb2+‐Ni2+, Cd2+‐Hg2+, Ni2+‐Hg2+, Zn2+‐Pb2+, Ca2+‐Bi3+, Al3+‐Hg2+, and Ca2+‐Pb2+ were achieved on the columns of polyanilinezirconium(IV) arsenate cation exchanger. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Adsorption recovery of rhodium(III) in acidic chloride solutions by amine‐modified tannin gel
Authors: Morisada Shintaro , Rin Tetsuzen , Ogata Takeshi , Kim Yoen‐Ho , Nakano Yoshio 
Published: February 2012

AbstractA tannin gel (TG), synthesized from condensed tannin molecules, has the remarkable ability to adsorb various metal ions in aqueous solutions. In the present study, the adsorption behavior of rhodium ion [Rh(III)] in acidic chloride solutions was investigated using an amine‐modified tannin gel (ATG) prepared by the ammonia treatment of a TG. The ATG was able to adsorb Rh(III) in strong hydrochloric acid solutions, whereas the TG failed to adsorb it. This is because the amino group in the ATG can form a stable complex with Rh(III) compared to the hydroxy group. With increasing chloride ion concentration, the adsorption amount of Rh(III) onto the ATG decreased somewhat, while the number of chloride ligands in the Rh(III) complex was expected to increase. This suggests that the Rh(III) complexes with fewer chloride ligands are more favorable for adsorption onto the ATG. Also, the Rh(III) adsorbability of the ATG decreased significantly with decreasing initial pH because of the protonation of the hydroxy and amino groups in the ATG. The results obtained here indicate that in the Rh(III) adsorption onto the ATG, the solution pH is more influential than the chloride ion concentration. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Thermal energy storage by poly(styrene‐co‐p‐stearoylstyrene) copolymers produced by the modification of polystyrene
Authors: Alkan Cemil , Sarı Ahmet , Biçer Alper 
Published: February 2012

AbstractA series of poly(styrene‐co‐p‐stearoyl styrene) copolymers as novel polymeric solid–solid phase‐change materials (SSPCMs) were synthesized by the modification of polystyrene with stearoyl chloride. The chemical structure and crystalline morphology of the synthesized copolymers were determined with Fourier transform infrared spectroscopy and polarized optical microscopy, respectively. The thermal energy storage properties and thermal stability of the SSPCMs were investigated with differential scanning calorimetry and thermogravimetric analysis, respectively. In addition, the thermal conductivity of the SSPCMs was measured with a thermal property analyzer. Moreover, thermal cycling tests showed that the copolymers had good thermal reliability and chemical stability after being subjected to 5000 heating/cooling cycles. The synthesized poly(styrene‐co‐stearoyl styrene) copolymers as novel SSPCMs have considerable potential for thermal energy storage and temperature‐control applications. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Repeat percutaneous coronary revascularization: Indications and outcomes in a “Real World” cohort
Authors: Adlam David , Evans Nicholas , Malhotra Aneil , Midha Disha , Rowley Felicity , Hutchings David , Shin Mirae , Mole Guy , Stockenhuber Alexander , Lumb Mark , Wordsworth Jonathan , Frantal Sophie , Forfar J. Colin 
Published: February 2012

AbstractObjectives: To investigate rates of and reasons for second and subsequent stent procedures in an unselected, “real‐world” population. Background: Repeat stenting is the primary difference reported in clinical trials of alternative revascularization strategies. The incidence, indication, and outcome for repeat stenting in contemporary practice outside the more selective populations of trials and registries has not been described. Method: All patients undergoing a first percutaneous coronary intervention (PCI) procedure with stenting from January 2001 to August 2009 (10,509) from a large UK tertiary referral and district general hospital were identified. Mortality and the incidence, timing, and indication for repeat revascularization in this population were investigated from patient records. Results: Of 10,509 patients undergoing a first PCI and stent implant 23.5% underwent repeat angiography of which 11.2% required repeat PCI and 2% coronary artery bypass grafting (median follow‐up of 3.8 years). A total of 1.3% went on to a third PCI. The commonest indication for repeat stenting was disease progression remote from the original stent (46%) and planned staged PCI (23%); 21% had a stent‐related indication. Functional assessment before repeat stenting was used in one‐third of stable patients. Mortality was 2.5% per annum. Conclusions: In contemporary practice, patients undergoing a first stenting procedure have a low subsequent mortality, and the substantial majority (86.4%) requires no further revascularization over a median 3.8 year follow‐up. For those who do require repeat stenting, this is most commonly at a site remote from the first stent. © 2012 Wiley Periodicals, Inc.
CO2 Separation by Carbonate Looping Including Additional Power Generation with a CO2‐H2O Steam Turbine
Authors: Strelow M. , Schlitzberger C. , Röder F. , Magda S. , Leithner R. 
Published: February 2012

AbstractUsually the separation of CO2 from the flue gas in power plants is connected with high efficiency losses, independent of separation technology. The reason is that the separation processes of the pre‐ or post‐combustion capture or using an oxy‐fuel process as proposed today result in additional energy consumption. But there are also sorbents, e.g., lime, that form carbonates and release heat at a temperature level of about 600 °C and will be calcinated at higher temperatures (about 900 °C). Integration of these processes in the design of a conventional power plant and production of additional power output by integration of another Rankine cycle using the separated CO2 and steam minimizes efficiency losses. The simulation and the results of such a CO2 capture process are described in this paper.
Development and Testing of an Interconnected Fluidized‐Bed System for Chemical Looping Combustion
Authors: Ding N. , Zheng Y. , Wang W. R. , Luo C. , Fu P. F. , Zheng C. G. 
Published: February 2012

AbstractChemical looping combustion (CLC) is a novel combustion method for CO2 capture. A cold model of an interconnected fluidized‐bed system for CLC was designed and operated, in which the loop seal was used to balance the pressure difference and prevent gas mixing between the fuel reactor (FR) and air reactor (AR). The effects of the operating parameters on solid circulation rate, pressure profiles, and solid distribution are investigated. The experimental results indicate that high solid circulation rates between the FR and AR can be achieved and provide a wide range of stable operating conditions. No gas leakages between the FR and AR are detected. The suitable operating conditions are optimized for the cold model of CLC which could pave the way for further design, improvement, and operation of the hot prototype.
Meilenstein Salicylsäuresynthese
Authors: Kleemann Axel , Offermanns Heribert 
Published: February 2012

AbstractIn frühchristlicher Zeit wurden Bemühungen, Krankheiten zu heilen häufig als Eingriff in die göttliche Schöpfung, ja als Gotteslästerungen eingestuft (“Pfuscht dem Herrgott nicht ins Handwerk!” [9]). Der Mensch hat aber gelernt, Krankheiten nicht als gottgegeben hinzunehmen, sondern zu bekämpfen. Über Tausende von Jahren standen der Heilkunde aber nur die Schätze der Natur (Heilpflanzen, tierische Produkte und anorganische Stoffe) zur Verfügung. Erst zu Anfang des 19. Jahrhunderts gelang es, aus den Stoffgemischen der Drogen reine Naturstoffe zu isolieren, zu charakterisieren sowie sie zur Optimierung von Verträglichkeit und Resorption durch Partialsynthese zu modifizieren und therapeutisch zu nutzen. Am 2. Januar 1874 schlug die Geburtsstunde der industriellen chemischen Wirkstoffsynthese und die Wiege stand in der Villa Adolpha in Dresden, wo Hermann Kolbe und seine Schüler Rudolph Schmitt und Friedrich von Heyden den Wirkstoff Salicylsäure, der bis dahin nur aus Weidenrinde oder der Spirapflanze gewonnen werden konnte, mit rein chemischen Methoden synthetisierten. Heute kann man sowohl alle Naturstoffe durch Totalsynthese gewinnen als auch am “Reißbrett” konzipierte Moleküle synthetisieren. Bio‐ und Gentechnologie erweitern heute die Möglichkeiten, neue Therapeutika zu gewinnen.
Mehr als nur ein Längenrekord
Authors: Feil Sylvia 
Published: February 2012

AbstractEinen neuen Längenrekord für Kohlenstoffbindungen in Alkanen hat Peter Schreiner aus Gießen aufgestellt. Vor allem aber belegt er, wie wichtig der Anteil anziehender intramolekularer Wechselwirkungen für die Stabilität eines Moleküls ist.
Coordination Environment of Highly Concentrated Solutions of CuII in Ionic Liquids through a Multidisciplinary Approach
Authors: Caporali Stefano , Chiappe Cinzia , Ghilardi Tiziana , Pomelli Christian Silvio , Pinzino Calogero 
Published: February 2012

AbstractThe coordination environment around CuII in highly concentrated solutions of copper(II) salts (CuCl2 and Cu(Tf2N)2) in two pure ionic liquids bearing the same anion, namely, 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf2N]) and 1‐butyl‐3‐methylimidazolium chloride ([bmim]Cl), is investigated by X‐ray photoelectron spectroscopy (XPS), UV/Vis spectroscopy, EPR spectroscopy and DFT calculations. Moreover, the electrochemical behavior of these mixtures is studied. Whereas reversible reduction of CuII to copper metal can be observed in the 1:1 [bmim][Tf2N]:Cu(Tf2N)2 solution, 2:1 and 1:1 [bmim]Cl:CuCl2 mixtures showed one‐electron reduction of CuII to CuI with formation of a permanent deposit of CuCl. XPS, UV/Vis and EPR spectra as well as DFT calculations suggest the formation in [bmim]Cl of dynamic coordination complexes arising from the interaction between CuCl2 and [bmim]+Cl− . The two long‐lived situations are probably trigonal and deformed tetrahedral copper(II) chloride coordination complexes ([CuCl3]− and [CuCl4]2−, respectively).
PTA‐Stabilized Ruthenium and Platinum Nanoparticles: Characterization and Investigation in Aqueous Biphasic Hydrogenation Catalysis
Authors: Debouttière Pierre‐Jean , Coppel Yannick , Denicourt‐Nowicki Audrey , Roucoux Alain , Chaudret Bruno , Philippot Karine 
Published: February 2012

AbstractVery small ruthenium and platinum nanoparticles have been prepared from organometallic complexes by using 1,3,5‐triaza‐7‐phosphaadamantane (PTA) as stabilizer, which allowed their easy dispersion into water. These nanoparticles were fully characterized by different techniques. In particular, the coordination of PTA to the surfaces of the particles was studied by NMR spectroscopy. The potential of these nanoparticles as catalysts was investigated in aqueous biphasic catalysis; olefins and arene derivatives were hydrogenated under mild conditions of temperature and pressure with interesting conversions and selectivities despite the change of environment they underwent after their dissolution in water.
Conjugation to Biocompatible Dendrimers Increases Lanthanide T2 Relaxivity of Hydroxypyridinone Complexes for Magnetic Resonance Imaging
Authors: Klemm Piper J. , Floyd III William C. , Andolina Christopher M. , Fréchet Jean M. J. , Raymond Kenneth N. 
Published: February 2012

AbstractMagnetic resonance imaging (MRI) contrast agents represent a worldwide billion‐dollar market annually. While T1 relaxivity enhancement contrast agents receive greater attention and a significantly larger market share, the commercial potential for T2 relaxivity enhancing contrast agents remains a viable diagnostic option because of their increased relaxivity at high field strengths. Improvement of the contrast and biocompatibility of T2 MRI probes may enable new diagnostic prospects for MRI. Paramagnetic lanthanides have the potential to decrease T1 and T2 proton relaxation times, but are not commercially used in MRI diagnostics as T2 agents. In this article, oxygen donor chelates (hydroxypyridinone, HOPO, and terephthalamide, TAM) of various lanthanides are demonstrated as biocompatible macromolecular dendrimer conjugates for the development of T2 MRI probes. These conjugates have relaxivities of up to 374 mM–1 s–1 per dendrimer, high bioavailability, and low in vitro toxicity.
Synthesis of a Photochromic Fused 2H‐Chromene Capable of Generating a Single Coloured Species
Authors: Sousa Céu M. , Pina João , Seixas de Melo João , Berthet Jerome , Delbaere Stephanie , Coelho Paulo J. 
Published: February 2012

AbstractA new photochromic fused 2H‐chromene that has a dehydropyran bridge between the pyran double bond and the benzene ring was prepared. Unlike standard 2H‐chromenes that give rise to two coloured species (one short‐ and one long‐lived) under UV irradiation, flash photolysis studies on this particular 2H‐chromene show that the opening of the pyran ring led to the formation of a single, coloured, open species that bleaches to the uncoloured initial form in <1 ms. The design of this fused 2H‐chromene avoids the formation of the undesirable long‐lived, transoid–trans, coloured, open form; therefore, the colour fades very quickly, according to monoexponential kinetics, without the persistence of any residual colour commonly observed in 2H‐chromenes. Acid treatment of 4‐[(ethoxycarbonyl)methyl]‐2H‐chromenes led to the formation of lactones.
Asymmetric Michael Addition Reactions between 3‐Substituted Benzofuran‐2(3H)‐ones and 1,1‐Bis(phenylsulfonyl)ethylene Catalyzed by Bifunctional Catalysts Containing Tertiary Amine and Thiourea Groups
Authors: Li Xin , Zhang Yue‐Yan , Xue Xiao‐Song , Jin Jia‐Lu , Tan Bo‐Xuan , Liu Cong , Dong Nan , Cheng Jin‐Pei 
Published: February 2012

AbstractHighly enantioselective catalytic conjugate additions of 3‐substituted benzofuran‐2(3H)‐ones to 1,1‐bis(phenylsulfonyl)ethylene in the presence of catalysts based on Cinchona alkaloids and containing tertiary amine and thiourea groups have been developed. Good to excellent stereoselectivities (up to 99 % ee) could be achieved. An interesting effect of substituent positions on stereoselectivities was observed, and a theoretical study to explain this phenomenon was undertaken.
Emotions in context: Anger causes ethnic bias but not gender bias in men but not women
Authors: Kuppens Toon , Pollet Thomas V. , Teixeira Cátia P. , Demoulin Stéphanie , Craig Roberts S. , Little Anthony C. 
Published: February 2012

AbstractEmotions influence information processing because they are assumed to carry valuable information. We predict that induced anger will increase ethnic but not gender intergroup bias because anger is related to conflicts for resources, and ethnic groups typically compete for resources, whereas gender groups typically engage in relations of positive interdependence. Furthermore, we also predict that this increased ethnic intergroup bias should only be observed among men because men show more group‐based reactions to intergroup conflict than women do. Two studies, with 65 and 120 participants, respectively, indeed show that anger induction increases ethnic but not gender intergroup bias and only for men. Intergroup bias was measured with an implicit measure. In Study 2, we additionally predict (and find) that fear induction does not change ethnic or gender intergroup bias because intergroup bias is a psychological preparation for collective action and fear is not associated with taking action against out‐groups. We conclude that the effect of anger depends on its specific informational potential in a particular intergroup context. These results highlight that gender groups differ on a crucial point from ethnic groups and call for more attention to the effect of people's gender in intergroup relations research. Copyright © 2012 John Wiley & Sons, Ltd.
Study on Platinum and Copper Nanosheets Alloys Supported on Mesoporous Titanium Dioxide Doped with Carbon Black as Electrocatalysts in PEM Fuel Cells
Authors: Lei Yijie , Li Tong , Gu Jun , Yu Tao , Liu Jianguo , Zou Zhigang 
Published: February 2012

AbstractPlatinum and copper nanosheets alloys (Pt1–xCux nanosheets), prepared by the seed‐mediated growth method, are deposited on mesoporous titanium dioxide (TiO2) doped with carbon black by ultrasonic dispersion. The Pt5Cu nanosheet/carbon‐TiO2 (Pt5Cu NS/C‐TiO2) used for proton exchange membrane fuel cell (PEMFC) catalyst shows higher electrochemical surface area and exhibits better fuel cell performance than that of the commercial Pt/C catalyst. The Pt5Cu NS/C‐TiO2 also shows better stability than that of the commercial Pt/C when it is employed as the cathode catalyst in a single‐cell fuel cell.
Nanomaterials Based Electrochemical Sensing Applications for Safety and Security
Authors: Marín Sergio , Merkoçi Arben 
Published: February 2012

AbstractNanomaterials based sensing systems provide a new class of rapid and low cost detection alternatives with interest in the field of safety and security applications. In this review we report the recent trends in the use of various nanomaterials such as nanoparticles, carbon nanotubes, nanowires and graphene to detect different safety and security related analytes (i.e. microorganisms, toxins, pesticides and explosives). Nanomaterials are used either as modifiers of the electrochemical transducers or as labels with the objective to enhance the electrochemical signal, improve the stability and in general the performance of the detection systems including their cost‐efficiency. Most of the developed systems are shown to bring excellent improvements while being used in the laboratory. Their application in real sample and during in‐field monitoring still needs a long way while issues such as the reproducibility, stability, mass production capability of the designed devices etc. shouldn’t still yet be resolved.
Simultaneous Voltammetric Determination of Ascorbic Acid and Sulfite in Beverages Employing a Glassy Carbon Electrode Modified with Carbon Nanotubes within a Poly(Allylamine Hydrochloride) Film
Authors: Sartori Elen Romão , Fatibello‐Filho Orlando 
Published: February 2012

AbstractA glassy carbon electrode modified with functionalized multiwalled carbon nanotubes within a poly(allylamine hydrochloride) film was used for the simultaneous voltammetric determination of ascorbic acid and sulfite. The anodic peak potentials of ascorbic acid and sulfite oxidation at a MWCNTs‐PAH/GCE were found to be 0.005 V and 0.327 V (vs. Ag/AgCl (3.0 M KCl)), respectively by cyclic voltammetry, whereas at a GCE were 0.278 V and 0.722 V. Using linear sweep voltammetric technique, the obtained analytical curves were linear in the ascorbic acid and sulfite concentration range from 5.0 to 200.0 µM, with detection limits of 3.0 and 3.5 µM for ascorbic acid and sulfite, respectively. The proposed method was successfully used for the simultaneous determination of ascorbic acid and sulfite in fruit juices.
Nonlocal period parameters of frequency content characterization for near‐fault ground motions
Authors: Yang Dixiong , Wang Wei 
Published: February 2012

SUMMARYThis paper focuses on the frequency property analysis of near‐fault ground motions with and without distinct pulses, separately from the Chi‐Chi and Northridge earthquakes. Ten scalar period parameters of ground motions, especially several nonlocal period parameters, are considered. Two new nonlocal parameters, namely the mean period of Hilbert marginal spectrum (Tmh) and the improved characteristic period (Tgi), are suggested. Moreover, comprehensive comparison and analysis indicate that Tmh, Tgi and Tavg (average spectral period) can distinguish the low‐frequency components of near‐fault ground motions; Tm (mean period of Fourier amplitude spectrum) and To (smoothed spectral predominant period) represent the moderate‐ and high‐frequency components, respectively. The variance coefficient of predominant instantaneous frequency of Hilbert spectrum (Hcov) can be regarded as an alternative index to measure the non‐stationary degree of near‐fault ground motions. Finally, the velocity pulses and earthquake magnitude remarkably affect the frequency parameters of near‐fault ground motions. Copyright © 2012 John Wiley & Sons, Ltd.
Second, third, and fourth head and neck tumors. A progressive decrease in survival
Authors: León Xavier , Martínez Vicenç , López Montserrat , García Jacinto , Venegas María del Prado , Esteller Eduard , Quer Miquel 
Published: February 2012

AbstractBackgroundPatients with a first head and neck carcinoma have a high risk of successive neoplasms, many of which appear again in the head and neck. Second head and neck tumors have a poorer prognosis than first tumors, but data about the prognosis of third and fourth tumors in the head and neck are lacking.MethodsWe carried out a retrospective study of 4298 patients with a primary head and neck carcinoma. Survival and the characteristics of the first tumor, second tumor, and any successive tumors in the head and neck were analyzed.ResultsSecond and successive tumors showed a tendency to appear more frequently in the oral cavity and oropharynx and had a lower stage than that of index tumors. Five‐year survival rates after a first, second, third, and fourth tumors in the head and neck were 67.6%, 56.1%, 45.0%, and 32.1%, respectively.ConclusionSurvival decreased progressively with every new head and neck tumor. © 2012 Wiley Periodicals, Inc. Head Neck, 2012