bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and Performance of PVC/CNT Nanocomposite
Authors: Wang Xiao Hua , Mu Yuan Hua , Tang Qi , Li Chuan Qiang 
Published: February 2016

ABSTRACTThe PVC/CNT nanocomposite was prepared with commercial poly(vinyl chloride) (PVC) beads and multiwall carbon nanotube (CNT). The comparative values of the electromagnetic interference shielding effectiveness (EMI SE) and electrical conductivity of PVC/CNT nanocomposite in the presence and absence of PVC beads were described. The results showed that the EMI SE values and electrical conductivity values of PVC/CNT nanocomposite had increased compared to those without PVC beads. After the addition of PVC beads, both values of the EMI SE and electrical conductivity had also increased with the increasing of the amount of PVC bead on the PVC/CNT nanocomposite, and the PVC/CNT nanocomposite in the presence of PVC bead showed high EMI SE value (22.6 dB at 4.0 wt% CNT loading in the presence of 70 wt% bead) and high conductivity value (5.31×10−2S cm−1 at 1.0 wt% CNT loading in the presence of 70 wt% bead) at low CNT loading. Thus, PVC beads effectively play a major role in enhancing the EMI SE value and electrical conductivity value of the nanocomposite. To check the bead region and solvent‐dried CNT region in the nanocomposite, morphological studies have been done and morphological studies of the PVC/CNT nanocomposite supported the two‐phase regions in the composite and the selective dispersion of the CNT in the solvent‐dried phase has been clearly observed.
Olefinmetathese als aufstrebende Methode zur Herstellung von Pharmazeutika und Spezialchemikalien
Authors: Higman Carolyn S. , Lummiss Justin A. M. , Fogg Deryn E. 
Published: February 2016

AbstractDieser Kurzaufsatz behandelt die kürzliche Einführung molekularer Metathesekatalysatoren in die Produktion von Spezialchemikalien und Pharmazeutika.
Cationic Cobalt(III) Catalyzed Indole Synthesis: The Regioselective Intermolecular Cyclization of N‐Nitrosoanilines and Alkynes
Authors: Liang Yujie , Jiao Ning 
Published: February 2016

AbstractThe unique regioselectivity and reactivity of cobalt(III) in the direct cyclization of N‐nitrosoanilines with alkynes for the expedient synthesis of N‐substituted indoles is demonstrated. In the presence of a cobalt(III) catalyst, high regioselectivity was observed when using unsymmetrical meta‐substituted N‐nitrosoanilines. Moreover, internal alkynes bearing electron‐deficient groups, which are almost unreactive in the [Cp*RhIII]‐catalyzed system, display good reactivity in this transformation.
An Alignment Medium for Measuring Residual Dipolar Couplings in Pure DMSO: Liquid Crystals from Graphene Oxide Grafted with Polymer Brushes
Authors: Zong Wen , Li Gao‐Wei , Cao Jiang‐Ming , Lei Xinxiang , Hu Mao‐Lin , Sun Han , Griesinger Christian , Tan Ren Xiang 
Published: February 2016

AbstractResidual dipolar couplings (RDCs) have attracted attention in light of their great impact on the structural elucidation of organic molecules. However, the effectiveness of RDC measurements is limited by the shortage of alignment media compatible with widely used organic solvents, such as DMSO. Herein, we present the first liquid crystal (LC) based alignment medium that is compatible with pure DMSO, thus enabling RDC measurements of polar and intermediate polarity molecules. The liquid crystals were obtained by grafting polymer brushes onto graphene oxide (GO) using free radical polymerization. The resulting new medium offers several advantages, such as absence of background signals, narrow line shapes, and tunable alignment. Importantly, this medium is compatible with π‐conjugated molecules. Moreover, sonication‐induced fragmentation can reduce the size of GO sheets. The resulting anisotropic medium has moderate alignment strength, which is a prerequisite for an accurate RDC measurement.
Enhanced Pseudocapacitance in Multicomponent Transition‐Metal Oxides by Local Distortion of Oxygen Octahedra
Authors: Lee Hyeon Jeong , Lee Ji Hoon , Chung Sung‐Yoon , Choi Jang Wook 
Published: February 2016

AbstractAnomalously high pseudocapacitance of a metal oxide was observed when Ni, Co, and Mn were mixed in a solid solution. Analysis by X‐ray absorption near‐edge spectroscopy (XANES) identified a wider redox swing of Ni as the origin of the enlarged pseudocapacitance. Ab initio DFT calculations revealed that aliovalent species resulting from the copresence of multiple transition metals can generate permanent local distortions of [NiO6] octahedra. As this type of distortion breaks the degenerate eg level of Ni2+, the Jahn–Teller lattice instability necessary for the Ni2+/3+ redox flip can be effectively diminished during charge–discharge, thus resulting in the significantly increased capacitance. Our findings highlight the importance of understanding structure–property correlation related to local structural distortions in improving the performance of pseudocapacitors.
Synergistic Kinetic Resolution and Asymmetric Propargyl Claisen Rearrangement for the Synthesis of Chiral Allenes
Authors: Liu Yangbin , Liu Xiaohua , Hu Haipeng , Guo Jing , Xia Yong , Lin Lili , Feng Xiaoming 
Published: February 2016

AbstractThe asymmetric propargyl Claisen rearrangement provides a convenient entry to chiral allene motifs. Herein, we describe the development of a kinetic resolution and asymmetric rearrangement of racemic propargyl vinyl ethers. This transformation afforded chiral allene products along with the enantiomerically enriched substrate in good yields with excellent diastereo‐ and enantioselectivity. The complete chirality transfer and facially selective rearrangement enabled the simultaneous construction of an axially chiral allenic unit and a quaternary carbon stereocenter.
Nitrogen, Phosphorus, and Sulfur Co‐Doped Hollow Carbon Shell as Superior Metal‐Free Catalyst for Selective Oxidation of Aromatic Alkanes
Authors: Yang Shuliang , Peng Li , Huang Peipei , Wang Xiaoshi , Sun Yongbin , Cao Changyan , Song Weiguo 
Published: February 2016

AbstractMetal‐free heteroatom‐doped carbocatalysts with a high surface area are desirable for catalytic reactions. In this study, we found an efficient strategy to prepare nitrogen, phosphorus, and sulfur co‐doped hollow carbon shells (denote as NPS‐HCS) with a surface area of 1020 m2 g−1. Using a poly(cyclotriphosphazene‐co‐4,4′‐sulfonyldiphenol) (PZS) shell as carbon source and N, P, S‐doping source, and the ZIF‐67 core as structural template as well as extra N‐doping source, NPS‐HCS were obtained with a high surface area and superhydrophilicity. All these features render the prepared NPS‐HCS a superior metal‐free carbocatalyst for the selective oxidation of aromatic alkanes in aqueous solution. This study provides a reliable and facile route to prepare doped carbocatalysts with enhanced catalytic properties.
Synthesis, DNA binding, nuclease activity and cytotoxic studies of a wheel‐shaped octanuclear copper(II) complex based on 1,2,4‐triazole
Authors: Li Dong‐Dong , Zhang Na , Dai Lin‐Lin , Yang Zi‐Bo , Tao Zun‐Wei 
Published: February 2016

The antitumor activity shown by many platinum complexes has produced a strong interest in research of new organometallic compounds. Among the metal compounds synthesized and tested, copper compounds have received considerable attention because of their cytotoxic activity against solid tumors. A novel wheel‐shaped octanuclear copper(II) complex with a 1,2,4‐triazole derivative ligand formulated as [Cu8L4](ClO4)8⋅11H2O (1) (L = 3,5‐bis((bis(2‐hydroxylethyl)amino)methyl)‐4 H‐1,2,4,‐triazole‐4‐amine) has been synthesized and structurally characterized. In 1, eight Cu atoms are linked through 1,2,4‐triazole units and alkoxide bridges to form a centrosymmetric octanuclear Cu(II) metallomacrocycle. The interaction of complex 1 with calf thymus DNA has been studied using UV absorption, fluorescence and circular dichroism spectroscopies, viscosity measurements and cyclic voltammetry. The apparent binding constant (kapp) value for 1 is 1.59 × 105 M−1. Furthermore, complex 1 displays efficient oxidative cleavage of supercoiled DNA in the presence of external agents, the rate constant for the conversion of supercoiled to nicked DNA being 2.67 × 10−5 s−1. Interestingly, cytotoxicity studies on the MCF‐7 human breast cancer cell line show that the IC50 value of 1 is less than that of cisplatin for the same cell line, revealing that it has the potential to act as an effective metal‐based anticancer drug. Copyright © 2016 John Wiley & Sons, Ltd.
Ceramic hollow fiber‐supported PDMS composite membranes for oxygen enrichment from air
Authors: Pian Changhong , Shen Jie , Liu Gongping , Liu Zhengkun , Jin Wanqin 
Published: February 2016

AbstractOxygen‐enriched air has attracted increasing attention owing to its potential industrial application. In this work, ceramic hollow fiber‐supported polydimethylsiloxane (PDMS) composite membranes were applied in separation of oxygen from air. The influence of PDMS layer thickness, pressure difference, temperature, and feed concentration on the oxygen‐enriching performance was systematically investigated. The results indicated that the membrane (with the optimal PDMS layer thickness of 25 µm) achieved oxygen permeance of 104 GPU (1 GPU = 10−6 cm3 standard temperature and pressure (STP)/cm2 s cmHg) with O2/N2 ideal selectivity of 2.0 at room temperature and 0.1 MPa difference pressure. Over 10 days continuous operation, this enrichment performance kept stable, in which the oxygen concentration enriched from air can maintain about 30% by single‐stage separation through the membrane. Our work demonstrated that the ceramic hollow fiber‐supported PDMS composite membrane could be a competitive oxygen enrichment membrane for industry application. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.
Homogeneous and Heterogeneous Photocatalytic Water Oxidation by Persulfate
Authors: Fukuzumi Shunichi , Jung Jieun , Yamada Yusuke , Kojima Takahiko , Nam Wonwoo 
Published: February 2016

AbstractPhotocatalytic water oxidation by persulfate (Na2S2O8) with [Ru(bpy)3]2+ (bpy=2,2′‐bipyridine) as a photocatalyst provides a standard protocol to study the catalytic reactivity of water oxidation catalysts. The yield of evolved oxygen per persulfate is regarded as a good index for the catalytic reactivity because the oxidation of bpy of [Ru(bpy)3]2+ and organic ligands of catalysts competes with the catalytic water oxidation. A variety of metal complexes act as catalysts in the photocatalytic water oxidation by persulfate with [Ru(bpy)3]2+ as a photocatalyst. Herein, the catalytic mechanisms are discussed for homogeneous water oxidation catalysis. Some metal complexes are converted to metal oxide or hydroxide nanoparticles during the photocatalytic water oxidation by persulfate, acting as precursors for the actual catalysts. The catalytic reactivity of various metal oxides is compared based on the yield of evolved oxygen and turnover frequency. A heteropolynuclear cyanide complex is the best catalyst reported so far for the photocatalytic water oxidation by persulfate and [Ru(bpy)3]2+, affording 100 % yield of O2 per persulfate.
Heterogeneous and Homogeneous Routes in Water Oxidation Catalysis Starting from CuII Complexes with Tetraaza Macrocyclic Ligands
Authors: Prevedello Andrea , Bazzan Irene , Dalle Carbonare Nicola , Giuliani Angela , Bhardwaj Sunil , Africh Cristina , Cepek Cinzia , Argazzi Roberto , Bonchio Marcella , Caramori Stefano , Robert Marc , Sartorel Andrea 
Published: February 2016

AbstractSince the first report in 2012, molecular copper complexes have been proposed as efficient electrocatalysts for water oxidation reactions, carried out in alkaline/neutral aqueous media. However, in some cases the copper species have been recognized as precursors of an active copper oxide layer, electrodeposited onto the working electrode. Therefore, the question whether copper catalysis is molecular or not is particularly relevant in the field of water oxidation. In this study, we investigate the electrochemical activity of copper(II) complexes with two tetraaza macrocyclic ligands, distinguishing heterogeneous or homogeneous processes depending on the reaction media. In an alkaline aqueous solution, and upon application of an anodic bias to working electrodes, an active copper oxide layer is observed to electrodeposit at the electrode surface. Conversely, water oxidation in neutral aqueous buffers is not associated to formation of the copper oxide layer, and could be exploited to evaluate and optimize a molecular, homogeneous catalysis.
Integrated enzyme production lowers the cost of cellulosic ethanol
Authors: Johnson Eric 
Published: February 2016

AbstractPrevious studies of cellulosic‐ethanol production have shown that the cost of producing cellulase is surprisingly significant, and that reducing this cost is key to making cellulosic‐ethanol economically viable. This study confirms that finding, and compares the costs of the three approaches for producing cellulase: off‐site, on‐site, and integrated. It finds that the integrated method is the lowest cost, primarily because it substitutes an inexpensive feedstock, biomass, for a relatively expensive one, glucose. This substitution also makes the ethanol a 100% second‐generation biofuel, i.e., it uses no ‘food for fuel’. This study also compares the activity of cellulase produced by the integrated method versus that produced by the off‐site method. Laboratory trials of the two show the ‘integrated’ cellulase to be better or equal to commercially available ‘off‐site’ cellulase in converting cellulose to sugar. © 2016 The Authors. Biofuels, Bioproducts, Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd.
Synthesis of chiral 2‐alkanols from n‐alkanes by a P. putida whole‐cell biocatalyst
Authors: Tieves Florian , Erenburg Isabelle N. , Mahmoud Osama , Urlacher Vlada B. 
Published: February 2016

ABSTRACTThe cytochrome P450 monooxygenase CYP154A8 from Nocardia farcinica was previously found to catalyze hydroxylation of linear alkanes (C7–C9) with a high regio‐ and stereoselectivity. The objective of this study was to integrate CYP154A8 along with suitable redox partners into a whole‐cell system for the production of chiral 2‐alkanols starting from alkanes. Both recombinant Escherichia coli and Pseudomonas putida whole‐cell biocatalysts tested for this purpose showed the ability to produce chiral alkanols, but a solvent tolerant P. putida strain demonstrated several advantages in the applied biphasic reaction system. The optimized P. putida whole‐cell system produced ∼16 mM (S)‐2‐octanol with 87% ee from octane, which is more than sevenfold higher than the previously described system with isolated enzymes. The achieved enantiopurity of the product could further be increased up to 99% ee by adding an alcohol dehydrogenase (ADH) to the alkane‐oxidizing P. putida whole‐cell systems. By using this setup for the individual conversions of heptane, octane or nonane, 2.6 mM (S)‐2‐heptanol with 91% ee, 5.4 mM (S)‐2‐octanol with 97% ee, or 5.5 mM (S)‐2‐nonanol with 97% ee were produced, respectively. The achieved concentrations of chiral 2‐alkanols are the highest reported for a P450‐based whole‐cell system so far. Biotechnol. Bioeng. 2016;113: 1845–1852. © 2016 Wiley Periodicals, Inc.
The impact of self on materialism among teenagers
Authors: de Araujo Gil Luciana , Leckie Civilai , Johnson Lester 
Published: February 2016

AbstractNo previous research has investigated the relationship between the concept of self and materialism, especially among teenagers. Our study seeks to reverse this trend by examining how independent self‐construal and interdependent self‐construal affect materialism among Brazilian teenagers (grades 7 through 12). Hypotheses were tested using structural equation modelling. We find that independent self‐construal has a positive effect on materialism. Furthermore, we created three sub‐constructs out of the original interdependent self‐construal construct, none of which affected materialism in the same way. Group dependency, a need to achieve the group's authorisation, increases materialism; group loyalty, an attitude of group fidelity, has no effect on materialism; and group respect, a respect for group decision, diminishes materialism. These are interesting results, because they question our prior beliefs on the matter and introduce new factors into the scholarly discussion of this issue. Copyright © 2016 John Wiley & Sons, Ltd.
Treatment no‐show in forensic outpatients with ADHD
Authors: Woicik Kasja , van der Lem Rosalind , Sijtsema Jelle J. , Bogaerts Stefan 
Published: February 2016

ABSTRACTBackground‘No‐show’ is important in today's mental healthcare services, yet in forensic psychiatry, little is known about its relationship to general and disorder‐specific patient characteristics.AimsThe aim of this article is to determine the prevalence of no‐show and any general and disorder‐specific features associated with no‐show in a cohort of offenders with attention deficit hyperactivity disorder registered at a specialist forensic mental health clinic.MethodsParticipants were 118 adult men with a mean age just over 32 years (SD 8.75) attending forensic mental health outpatient clinics in the Netherlands who had a primary diagnosis of attention deficit hyperactivity disorder and who had been aggressive and/or delinquent.ResultsOver a 1‐year period, most patients (101, 86%) missed at least one appointment. The average number of appointments offered was 37.88 (SD = 27.27), and the average number of no‐shows was 6.53 (SD = 5.99) per patient. Multivariate linear regressions showed a 10‐fold likelihood of later no‐shows if the first appointment was missed; not showing up after the intake procedure was also associated with higher rates of later no‐show. None of the disorder‐specific characteristics contributed to the problem.ConclusionsNo‐show is of particular concern in forensic mental health settings. In the current study, no‐show was primarily associated with features related to the time of initial consultation. More attention should thus be paid at this stage to using a standard method of assessing a wider range of variables likely to affect attendance. Copyright © 2016 John Wiley & Sons, Ltd.
Synergetic Behavior of TiO2‐Supported Pd(z)Pt(1−z) Catalysts in the Green Synthesis of Methyl Formate
Authors: Baldovino‐Medrano Víctor G. , Pollefeyt Glenn , Bliznuk Vitaliy , Van Driessche Isabel , Gaigneaux Eric M. , Ruiz Patricio , Wojcieszak Robert 
Published: February 2016

AbstractMethyl formate (MF) is a valuable platform molecule, the industrial production of which is far from being green. In this contribution, TiO2‐supported Pd(z)Pt(1−z) catalysts were found to be effective in the green synthesis of methyl formate (MF)—at T=323 K and ambient pressure—through methanol (MeOH) oxidation. Two series of catalysts with similar bulk Pd/(Pd+Pt) molar ratios, z, were prepared; one by a water‐in‐oil microemulsion (MicE) method and the other by an incipient wetness impregnation (IWI). The MicE method led to more efficient catalysts owing to a weak influence of z on particle size distributions and nanoparticles composition. Pd(z)Pt(1−z)‐MicE catalysts exhibited strong synergistic effects for MF production but weak synergistic effects for MeOH conversion. The catalytic performance of Pd(z)Pt(1−z)‐MicE was superior to that of Pd(z)Pt(1−z)‐IWI catalysts despite the latter displaying synergetic effects during the reaction. The catalytic behavior of TiO2‐supported Pd(z)Pt(1−z) catalysts was explained from correlations between XRD, TEM, and X‐ray photoelectron spectroscopy characterizations.
Cyclodextrin‐Grafted Silica‐Supported Pd Nanoparticles: An Efficient and Versatile Catalyst for Ligand‐Free C−C Coupling and Hydrogenation
Authors: Martina Katia , Baricco Francesca , Caporaso Marina , Berlier Gloria , Cravotto Giancarlo 
Published: February 2016

AbstractSilica is an extremely versatile support, which is capable of hosting metal nanoparticles (NPs) and enhancing their stability and reactivity. In this study, a novel cyclodextrin/silica support for Pd NPs, which we have denoted Pd/Si‐CD, has been prepared. The highly efficient and homogeneous impregnation of small palladium nanoparticles on this support has been carried out under conventional conditions, and ultrasound irradiation has been shown to have a beneficial effect on catalyst preparation. The catalyst exhibited excellent activity in ligand‐free C−C Suzuki and Heck couplings with a large number of aryl iodide and bromides, in which microwave irradiation use cuts down reaction time. Pd/Si‐CD have shown high activity and selectivity in the hydrogenation reaction, and the semihydrogenation of phenyl acetylene was also studied with excellent results.
Palladium Nanoparticles Immobilized on Magnetic Porous Carbon Derived from ZIF‐67 as Efficient Catalysts for the Semihydrogenation of Phenylacetylene under Extremely Mild Conditions
Authors: Li Xinlin , Zhang Wei , Liu Yansheng , Li Rong 
Published: February 2016

AbstractA new magnetic porous carbon (MDPC) derived from metal–organic frameworks (MOFs) was synthesized successfully through the direct carbonization of ZIF‐67 crystals and utilized as a support for Pd nanocatalysts. The prepared MDPC not only retains the original morphology of ZIF‐67 crystals but also provides a high surface area and excellent magnetic properties. The designed catalysts (Pd‐MDPC) were tested in the semihydrogenation of phenylacetylene under extremely mild conditions. The Pd nanoparticles are highly dispersed on the MDPC matrix without aggregation and exhibited an excellent catalytic activity and high selectivity toward olefins under mild conditions (25 °C, H2 1 atm). The Pd‐MDPC catalysts were further investigated in the semihydrogenation of several other terminal alkynes. Compared with most traditional carbon materials, such as activated carbon and carbon nanotubes, the MDPC possesses an admirable magnetism so that it could be separated magnetically from the reaction system. Our study indicates that MOF‐derived porous carbon is a suitable support for noble‐metal nanocatalysts and has promise in the field of nanocatalysis.
Mechanochemical Synthesis of a Carboxylated Carbon Catalyst and Its Application in Cellulose Hydrolysis
Authors: Shrotri Abhijit , Kobayashi Hirokazu , Fukuoka Atsushi 
Published: February 2016

AbstractA carbon catalyst containing a high density of carboxyl groups was prepared by solvent‐free mechanochemical oxidation of activated carbon by using persulfate salts as the oxidant. The mechanochemical oxidation preferentially oxidized the carbon to introduce carboxyl groups without incorporation of sulfonated groups. The material exhibited hydrophilic behavior and was easily dispersed in water. Upon mix‐milling, the oxidized carbon showed good catalytic activity for the hydrolysis of cellulose, even at a low catalyst loading. Glucose was obtained in 85 % yield from mix‐milled cellulose in the presence of a trace amount of HCl after a reaction time of 20 min.
Superior Catalysts for Oxygen Reduction Reaction Based on Porous Nanostars of a Pt, Pd, or Pt–Pd Alloy Shell Supported on a Gold Core
Authors: Venarusso Luna B. , Bettini Jefferson , Maia Gilberto 
Published: February 2016

AbstractThe aims of this study are to synthesize porous nanostars (PNSs) composed of a Pt, Pd, or Pt–Pd alloy shell supported on a gold core and to demonstrate their improved electrocatalytic activity towards the oxygen reduction reaction (ORR). The catalysts contain homogeneous, porous, star‐shaped, large‐sized structures (50 or 20 nm on average), with a covering pattern of Pt or Pt–Pd alloy nanodendritic particles of up to 5 nm. The synthesized PNS catalysts catalyze the ORR effectively, offering high performance in terms of Pt group metals mass‐specific activity, electrochemically active surface area (ECSA), specific ECSA, and specific activity, with high half‐wave potential values (0.93–0.96 V).