bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrode‐driven Regioselective Oxidation of Cinnamyl Alcohol by use of Thin Biologically Active Chloroperoxidase Composite Films
Authors: Tian Haitao , Mu Shilei , Li Hexing , Wu Xiaqin , Lu Zhongqing 
Published: August 2012

AbstractWe report an electrochemical system consisting of a modified glassy carbon (GC) electrode made from chitosan (Chi), chloroperoxidase (CPO), didodecyldimethylammonium bromide (DDAB) and Nafion for the bio‐electrocatalytic oxidation of cinnamyl alcohol. The CPO‐containing composite films were characterized and qualified by SEM, AFM, and cyclic voltammetry prior to synthesis applications. The thin Chi‐DDAB‐CPO composite film modified electrode gave a pair of well‐defined, quasi‐reversible redox peaks for CPO with an electron transfer rate of 2.3 s−1. The SEM and atomic force microscopy results obtained suggest that CPO in the thin film aggregated to form island‐like structures with sizes from 300 to 1000 nm and the average film thickness was 30 nm. Unlike conventional biological systems requiring external addition of excess H2O2, a controllable amount of H2O2 was continuously generated in the electrochemical system containing the CPO modified electrode. Almost all H2O2 generated in situ was used for catalytic oxidation of cinnamyl alcohol by CPO in the composite films. In addition, the stability and the lifetime of CPO composite films were improved significantly by coating a chitosan layer on the CPO layer. The preliminary results obtained for oxidation of cinnamyl alcohol using our electrochemical system gave a total yield of 51.8 % in contrast to 7.6 % for the conventional biological system with consumption of the same amount of enzyme. The Chi‐DDAB‐CPO‐Nafion films showed a total turnover number [molproduct molenzyme catalyst−1 (TTN)] of 80 500, 5‐fold more than those reported for oxidation of primary alcohols.
Architecture of PtCo Bimetallic Catalysts for Catalytic CO Oxidation
Authors: Xu Hong , Fu Qiang , Guo Xiaoguang , Bao Xinhe 
Published: August 2012

AbstractPtCo nanocatalysts have been synthesized and tested for both preferential oxidation of CO in excess H2 (PROX) and CO oxidation in the absence of H2 (COOX). Structural characterization and reaction results suggest that a PtCo catalyst architecture consisting of Pt nanoparticles decorated with highly dispersed CoO nanostructures is the active structure for both reactions. The highly active “CoO‐on‐Pt” catalysts can be prepared by reduction of as‐prepared PtCo catalysts at an intermediate temperature or by reactivation of an acid‐leached PtCo catalyst at a similar temperature. A comparative study of PtFe, PtCo, and PtNi catalysts reveals that interface confinement effects are dominant in all “TMOx‐on‐Pt” systems (TM=Fe, Co, and Ni). However, the activity and stability in both PROX and COOX reactions for each of these catalyst systems is variable.
Novel Single Stage Wash Sedimentator for Purification and Separation of Small Particles
Authors: Anlauf H. , Jeras J. , Feist M. , Scheffler J. , Nussbaumer M. 
Published: August 2012

AbstractThe starting point for the development of a novel process for simultaneous washing and separation of fine particles was the task of removing accompanying impurities from a crystallized plant extract and separating the crystals in a purified form. For this purpose, an innovative technical concept was developed, fundamental aspects were investigated on a laboratory scale, and the process was successfully carried out on a pilot scale in a joint project. In principle, the new method is based on a static sedimentation apparatus with integrated countercurrent washing, which operates continuously and produces a purified solid concentrate.
Development of 1‐Hydroxy‐2(1H)‐quinolone‐Based Photoacid Generators and Photoresponsive Polymer Surfaces
Authors: Ikbal Mohammed , Banerjee Rakesh , Atta Sanghamitra , Jana Avijit , Dhara Dibakar , Anoop Anakuthil , Singh N. D. Pradeep 
Published: August 2012

AbstractA new class of carboxylate and sulfonate esters of 1‐hydroxy‐2(1H)‐quinolone has been demonstrated as nonionic photoacid generators (PAGs). Irradiation of carboxylates and sulfonates of 1‐hydroxy‐2(1H)‐quinolone by UV light (λ≥310 nm) resulted in homolysis of weak NO bond leading to efficient generation of carboxylic and sulfonic acids, respectively. The mechanism for the homolytic NO bond cleavage was supported by time‐dependent DFT calculations. Photoresponsive 1‐(p‐styrenesulfonyloxy)‐2‐quinolone–methyl methacrylate (SSQL‐MMA) and 1‐(p‐styrenesulfonyloxy)‐2‐quinolone–lauryl acrylate (SSQL‐LA) copolymers were synthesized from PAG monomer 1‐(p‐styrenesulfonyloxy)‐2‐quinolone, and subsequently controlled surface wettability was demonstrated for the above‐mentioned photoresponsive polymers.
Large‐Scale and Facile Preparation of Pure Ammonia Borane through Displacement Reactions
Authors: Chen Xuenian , Bao Xiaoguang , Billet Beau , Shore Sheldon G. , Zhao Ji‐Cheng 
Published: August 2012

AbstractAmmonia borane (AB) is the most widely studied hydride for hydrogen storage in addition to being a useful reducing agent. Attempts to synthesize pure AB through simple displacement reactions date back to the 1960s; but have been thwarted by the formation of the diammoniate of diborane (DADB), an ionic byproduct. Based on our recent characterization of the formation mechanism of DADB, we have developed a large‐scale synthesis of pure AB by both increasing the basicity of the Lewis base of the borane carrier and using a nonpolar solvent to limit the formation of an intermediate, the ammonia diborane (AaDB). Conditions were optimized for the preparation of pure AB by two displacement reactions, either ammonia with dimethylsulfide borane or ammonia with dimethylaniline borane in toluene at room temperature. These procedures are also suitable for preparation of other amine boranes which had the same problem of forming ionic byproducts during displacement reactions.
Further Examples of the P‐O‐P Connection in Borophosphates: Synthesis and Characterization of Li2Cs2B2P4O15, LiK2BP2O8, and Li3M2BP4O14 (M=K, Rb)
Authors: Wang Ying , Pan Shilie , Shi Yunjing 
Published: August 2012

AbstractA new series of anhydrous mixed alkali‐metal borophosphates—Li2Cs2B2P4O15 (1), LiK2BP2O8 (2), Li3K2BP4O14 (3), and Li3Rb2BP4O14 (4)—have been successfully synthesized by using the conventional solid‐state reaction method. Compound 1 contains a novel fundamental building unit (FBU), [B4P8O30], with B/P=1:2. Compound 2 contains an FBU of [B2P4O16] with B/P=1:2. Compounds 3 and 4 are isotypic, and they have a [B(P2O7)2] unit as their FBU. In all four compounds, their FBUs are connected through corner sharing to generate layered anionic partial structures, and then further linked with metallic polyhedra to form three‐dimensional (3D) frameworks. Most interestingly, three of the four compounds contain direct P‐O‐P connections in their structures, which is extremely rare among borophosphates. Thermal analyses, IR spectroscopy, and UV/Vis/near‐IR diffuse reflectance spectroscopy have also been performed on the four title compounds.
Heat transfer and flow pattern in co‐current downward steam condensation in vertical pipes‐I: CFD simulation and experimental measurements
Authors: Dahikar Sachin K. , Ganguli Arijit A. , Gandhi Mayurkumar S. , Joshi Jyeshtharaj B. , Vijayan Pallippattu K. 
Published: August 2012

AbstractThe condensation of pure steam flowing inside a vertical tube has been extensively studied during the last nine decades. Considerable amount of experimental and analytical efforts can be found due to the significance of this subject in practice. In the present work (Part I), experimental investigations have been performed over a range of pressure (0.1 < P < 0.35 MPa) and internal tube diameter (Di = 10, 20 and 43 mm). A two‐dimensional computational fluid dynamic (CFD) simulations have been carried out commercial software Fluent 6.2 [Fluent 6.2, “User's Manual to FLUENT 6.2,” Fluent Inc., Lebanon, USA, 2005]. CFD results were used to predict the temperature profiles, pressure drop and the heat transfer coefficient, which was in close agreement with the experimental values. The film characteristics predicted by the CFD simulations have been compared qualitatively with the photographic images. Further, the CFD model developed in Part I extended for the analysis of all the experimental data reported in the published literature. © 2012 Canadian Society for Chemical Engineering
Use of vinasse to produce slow‐release coated urea in spouted bed
Authors: da Rosa Gabriela Silveira , dos Santos Rocha Sandra Cristina 
Published: August 2012

AbstractThe aim of this work was to evaluate the influence of the operating conditions on the coating efficiency for urea coated in a spouted bed and to analyse the decrease of nitrogen volatilisation for the coated urea. Coating efficiencies in the range (from 44.24% to 73.7%) were obtained for the different process conditions applied. Volatilisation analyses showed that the polymer film coating provided a decrease of the nitrogen loss in the range from 3% to 57%. The use of vinasse in substitution to the water in the coating suspension was tested for the optimum process conditions. © 2012 Canadian Society for Chemical Engineering
Targeting tyrosine kinases in cancer
Authors: Dumur Catherine I. , Idowu Michael O. , Powers Celeste N. 
Published: August 2012

AbstractBecause of knowledge gained in the field of cancer biology, clinicians are currently witnessing an explosion of molecular tests as companion diagnostics to targeted therapies against growth factor receptors and their signaling pathways. Such tests are being applied increasingly to cytology specimens as essential components of genomic medicine, because less invasive diagnostic procedures are becoming the norm. The objective of this review was to present an overview of the current and future role of cytopathology in molecular diagnostics, including the adequacy of cytology specimens for such studies. The authors also discuss the critical methodologic aspects of the molecular assays used for the selection of tyrosine kinase treatment for oncology patients. Cancer (Cancer Cytopathol) 2013. © 2012 American Cancer Society.
Intricate paths of cells and networks becoming “Cholinergic” in the embryonic chicken retina
Authors: Thangaraj Gopenath , Greif Alexander , Bachmann Gesine , Layer Paul G. 
Published: August 2012

AbstractCholine acetyltransferase (ChAT) and acetylcholinesterase (AChE) are the decisive enzymatic activities regulating the availability of acetylcholine (ACh) at a given synaptic or nonsynaptic locus. The only cholinergic cells of the mature inner retina are the so‐called starburst amacrine cells (SACs). A type‐I SAC, found at the outer border of the inner plexiform layer (IPL), forms a synaptic subband “a” within the IPL, while a type‐II SAC located at the inner IPL border projects into subband “d.” Applying immunohistochemistry for ChAT and AChE on sections of the chicken retina, we here have revealed intricate relationships of how retinal networks became dominated by AChE or by ChAT reactivities. AChE+ cells were first detectable in an embryonic day (E)4 retina, while ChAT appeared 1 day later in the very same cells; at this stage all are Brn3a+, a marker for ganglion cells (GCs). On either side of a faint AChE+ band, indicating the future IPL, pairs of ChAT+/AChE−/Brn3a− cells appeared between E7/8. Type‐I cells had increased ChAT and lost AChE; type‐II cells presented less ChAT, but some AChE on their surfaces. Direct neighbors of SACs tended to express much AChE. Along with maturation, subband “a” presented more ChAT but less AChE; in subband “d” this pattern was reversed. In conclusion, the two retinal cholinergic networks segregate out from one cell pool, become locally opposed to each other, and become dominated by either synthesis or degradation of ACh. These “cholinergic developmental divergences” may also have significant physiologic consequences. J. Comp. Neurol., 520:3181–3193, 2012. © 2012 Wiley Periodicals, Inc.
A comparison of the Cray XMT and XMT‐2
Authors: Bokhari Shahid H. , Bokhari Saniyah S. 
Published: August 2012

SUMMARYWe explore the comparative performance of the Cray XMT and XMT‐2 massively multithreaded supercomputers. We use benchmarks to evaluate memory accesses for various types of loops. We also compare the performance of these machines on matrix multiply and on three previously implemented dynamic programming algorithms. It is shown that the relative performance of these machines is dependent on the size (number of processors) of the configuration, as well as the size of the problem being evaluated. In particular, small configurations of the original XMT can sometimes show slightly better performance than larger configurations of the XMT‐2, for the same problem size. We note that, under heavy memory load, performance of loops can saturate well before the maximum number of processors available. This suggests that it may not always be useful to use the maximum number of processors for a specific run. We also show that manual restructuring of nested loops, including decreasing the parallelism, can result in major improvements in performance. The results in this paper indicate that careful exploration of the space of problem sizes, number of processors used, and choices of loop parallelization can yield substantial improvements in performance. These improvements can be very significant for production codes that run for extended periods of time. Copyright © 2012 John Wiley & Sons, Ltd.
Hyperfine Coupling Constants of β‐Phosphorylated Nitroxides: A Tool to Probe the Cybotactic Effect by Electron Paramagnetic Resonance
Authors: Audran Gérard , Brémond Paul , Marque Sylvain R. A. , Obame Germain 
Published: August 2012

AbstractNitrogen hyperfine coupling constants (hcc) aN of nitroxides measured by electron paramagnetic resonance are used to probe the cybotactic effect of solvents. A few articles (Janzen et al., Can. J. Chem. in 1982 for aHβ and Deng et al., J. Fluorine Chem. in 2002, both for aHβ and aFβ) dealt with the cybotactic effect on the hcc of atoms (hydrogen H, fluorine F, and phosphorus P) in β positions of nitroxides. They show either no significant change or an increase in aβ with aN. However, an early report by Il′Yasov et al. (Theor. Exp. Chem. 1976, 656) described a dramatic change in aPβ with the solvent and an anti‐correlation of aPβ with aN. We decided to reinvestigate that work using the N‐(2‐methylpropyl)‐N‐(1‐diethylphosphono‐2,2‐dimethylpropyl)‐N‐oxyl radical that carries both hydrogen and phosphorus atoms on the same carbon attached to the nitroxy moiety and that is highly persistent, in contrast to the nitroxide used by Il′Yasov. We observe the same trends as those observed by Il′Yasov, except that the solvent cybotactic effect on aN and aPβ is dramatically weaker in our case. We showed that aPβ is correlated to both the cohesive pressure c and the normalized Reichardt polar constant ETN, and that hydrogen‐bonding donor solvents exhibit a specific behavior.
The Adsorption of Oxygen and Coadsorption of CO and Oxygen on Structurally Well‐Defined PdAg Surface Alloys
Authors: Farkas Arnold P. , Diemant Thomas , Bansmann Joachim , Behm R. Jürgen 
Published: August 2012

AbstractThe dissociative interaction of oxygen with structurally well‐defined monolayer PdxAg1−x/Pd(111) surface alloys of different compositions, with well‐known distributions of the respective surface atoms (A. K. Engstfeld et al., Phys. Chem. Chem. Phys. 2012, 14, 10754–10761), and the coadsorption of/reaction with CO on oxygen pre‐covered surfaces were studied by high‐resolution electron energy loss spectroscopy (HREELS) and temperature‐programmed desorption/reaction spectroscopy (TPD/TPR). The impact of geometric ensemble effects as well as electronic ligand and strain effects on the adsorption and reaction behaviour of the respective species on the bimetallic surfaces is elucidated and compared with related systems such as CO adsorption on similar surfaces and oxygen adsorption on a Pd67Ag33(111) bulk alloy surface. The data show a clear dominance of ensemble effects on the oxygen adsorption and CO coadsorption behaviour, with oxygen adsorption limited to threefold‐hollow sites on Pd3 sites, while the combined electronic effects, as evident from modifications in the adsorption and reaction characteristics on the Pd sites, are small.
Lowering Energy Barriers in Surface Reactions through Concerted Reaction Mechanisms
Authors: Sakong Sung , Mosch Christian , Lozano Ariel , Busnengo H. Fabio , Groß Axel 
Published: August 2012

AbstractAny technologically important chemical reaction typically involves a number of different elementary reaction steps consisting of bond‐breaking and bond‐making processes. Usually, one assumes that such complex chemical reactions occur in a step‐wise fashion where one single bond is made or broken at a time. Using first‐principles calculations based on density functional theory we show that the barriers of rate‐limiting steps for technologically relevant surface reactions are significantly reduced if concerted reaction mechanisms are taken into account.
Quasi‐Homogeneous Oxidation of Glycerol by Unsupported Gold Nanoparticles in the Liquid Phase
Authors: Skrzyńska Elżbieta , Ftouni Jamal , Girardon Jean‐Sébastien , Capron Mickaël , Jalowiecki‐Duhamel Louise , Paul Jean‐François , Dumeignil Franck 
Published: August 2012

AbstractA quasi‐homogeneous solution of gold nanoparticles prepared by the Turkevich method was used as an unconventional catalyst in the oxidation of glycerol (GLY) in the liquid phase. The highest obtained conversion was 100 % after 3 h of reaction at 100 °C under an oxygen atmosphere (5 bar). The main products were glyceric, glycolic, formic, tartronic, and oxalic acid with selectivities of 28, 36, 25, 9, and 2 %, respectively. Traces of hydroxypyruvic and acetic acid were also detected (combined selectivities below 1 %). To elucidate the reaction mechanism and specify the role of gold nanoparticles in the oxidation process, a series of experiments under various reaction conditions were carried out. The effect of reaction temperature, oxygen pressure, gold concentration, and GLY/base molar ratio was investigated. All catalytic results were systematically compared to the corresponding noncatalytic base‐induced transformations (blank tests). Such an approach allowed us to separate and clarify the respective driving parameters for the transformation of GLY (presence of a base and activity of the gold catalyst). The reaction mechanism comprised a series of oxidation and CC cleavage reactions, whereas additional oxidation–reduction reactions (of the Cannizzaro type) could also occur in the presence of the base.
Electron‐Rich Anthracene Semiconductors Containing Triarylamine for Solution‐Processed Small‐Molecule Organic Solar Cells
Authors: Choi Hyeju , Ko Haye Min , Cho Nara , Song Kihyung , Lee Jae Kwan , Ko Jaejung 
Published: August 2012

AbstractNew electron‐rich anthracene derivatives containing triarylamine hole stabilizers, 2,6‐bis[5,5′‐bis(N,N′‐diphenylaniline)‐2,2′‐bithiophen‐5‐yl]‐9,10‐bis‐[(triisopropylsilyl)ethynyl]anthracene (TIPSAntBT–TPA) and 2,6‐bis(5,5′‐bis{4‐[bis(9,9‐dimethyl‐9H‐fluoren‐2‐yl)amino]phenyl}‐2,2′‐bithiophen‐5‐yl)‐9,10‐bis‐[(triisopropylsilyl)ethynyl]anthracene (TIPSAntBT–bisDMFA), linked with π‐conjugated bithiophene bridges, were synthesized and their photovoltaic characteristics were investigated in solution‐processed small‐molecule organic solar cells (SMOSCs). These new materials exhibited superior intramolecular charge transfer from triarylamine to anthracene, leading to a more electron‐rich anthracene core that facilitated electron transfer into phenyl‐C61‐butyric acid methyl ester. Compared with TIPSAntBT and triarylamine, these materials show a threefold improvement in hole‐transporting properties and better photovoltaic performance in solution‐processed SMOSCs, with the best power conversion efficiency being 2.96 % at a high open‐circuit voltage of 0.85 V.
Inbreeding and outbreeding depression in Stylidium hispidum: implications for mixing seed sources for ecological restoration
Authors: Hufford Kristina M. , Krauss Siegfried L. , Veneklaas Erik J. 
Published: August 2012

AbstractThe benefits of composite rather than local seed provenances for ecological restoration have recently been argued, largely on the basis of maximizing evolutionary potential. However, these arguments have downplayed the potentially negative consequences of outbreeding depression once mixed provenances interbreed. In this study, we compared intraspecific F1 hybrid performance and molecular marker differentiation among four populations of Stylidium hispidum, a species endemic to Southwestern Australia. Multivariate ordination of 134 AFLP markers analyzed genetic structure and detected two clusters of paired sites that diverged significantly for marker variation along a latitudinal boundary. To test for outbreeding depression and to determine the consequences of molecular population divergence for hybrid fitness, we conducted controlled pollinations and studied germination and survival for three cross categories (within‐population crosses, short‐ and long‐distance F1 hybrids) for paired sites distributed within and between the two genetically differentiated regions. We found evidence of outbreeding depression in long‐distance hybrids (111–124 km), and inbreeding depression among progeny of within‐population crosses, relative to short‐distance (3–10 km) hybrids, suggesting an intermediate optimal outcrossing distance in this species. These results are discussed in light of the evolutionary consequences of mixing seed sources for biodiversity restoration.
Differentiation of Oxygen Atom Chirality in Copper(II) Complexes with Dipicolylamine‐Derived Ligands
Authors: Mikata Yuji , Fujimoto Tomomi , Imai Noko , Kondo Shin‐ichi 
Published: August 2012

AbstractThe ether coordination of the oxygen atom to the copper(II) center supported by dipicolylamine (DPA)‐derived ligands,N‐[2‐(2‐pyridylmethyloxy)ethyl]‐N,N‐bis(2‐pyridylmethyl)amine (LPy), N‐[2‐(2‐quinolylmethyloxy)ethyl]‐N,N‐bis(2‐pyridylmethyl)amine (LQ), N‐[3‐(2‐pyridylmethyloxy)‐1‐propyl]‐N,N‐bis(2‐pyridylmethyl)amine (L′Py), N‐{2‐[1‐(2‐pyridyl)ethyloxy]ethyl}‐N,N‐bis(2‐pyridylmethyl)amine (LPy*1), N‐[2‐(2‐pyridylmethyloxy)‐1‐propyl]‐N,N‐bis(2‐pyridylmethyl)amine (LPy*2), and N‐[2‐(carboxymethyloxy)ethyl]‐N,N‐bis(2‐pyridylmethyl)amine (HLCOO), have been examined. The factors that facilitate the coordination of the ether oxygen atom of these ligands to the copper center and the control of chirality around the copper‐coordinated oxygen atom are discussed. The copper center exhibits a pentacoordinate geometry with these ligands, as evidenced by X‐ray crystallography. The steric effect of the quinoline ring in the LQ complex prevents the coordination of a perchlorate anion to the copper center, which affords the pentacoordinate divalent complex with a shorter copper–oxygen bond than that for the corresponding pyridine ligand (LPy). The six‐membered chelate in the L′Py complex also exhibits a shorter Cu–O distance. The conformation of the oxygen atom of the LPy complex is unstable because of fast lone pair inversion, but this inversion is prevented for the complexes with chiral ligands, LPy*1 and LPy*2. Upon chelation to the metal center, the HLCOO ligand forms a pentacoodinate monomer complex that further affords a 1‐D polymer structure. With respect to the oxygen chirality, the water content of the solvent governs the formation of either a homochiral polymer (R‐R‐R‐R‐ or S‐S‐S‐S‐) or an alternative chirality polymer (R‐S‐R‐S‐). In this case, the isomers with respect to the oxygen chirality were separated and characterized.