bluuebunny/crossref_metadata_2025_split huggingface dataset:
MnO QD/Graphene Dot Fabrics: A Versatile Nanohybrid Material
Authors: Su Liwei , Jiang Jiajia , Wang Lianbang , Wang Yuanhao , Ren Manman 
Published: March 2015

AbstractQuantum dots (QDs) are attracting tremendous interests due to their small size and subsequently various unique physical/chemical merits, especially incorporating with graphene nanosheets (GNS). Up to now, it is significant but still a big challenge to exploit a facile and good‐adaptability method to prepare QDs/GNS nanohybrids. In this work, a gel‐like film (GF) mechanism was proposed for the first time, with easy operation, low cost, and universal applications in particular. By this route, millions of MnO QDs were homogeneously dispersed on the GNS surface, very similar to the dot fabric in real life, and presented superior long‐term and rate performances for lithium storage benefiting from the positive effect of QDs and GNS. The reversible capacity after 80 cycles was 766.8 mAh g−1, still higher than the theoretical value of MnO. More importantly, this GF method has universal adaptability for several types of MO (where M=Mn, Co, Fe, Ni) QDs/GNS nanohybrids. This work may disclose new ways in understanding the formation of QDs/GNS and enlighten us on developing brilliant materials for powerful devices and electrochemical catalysts.
Unilamellar Vesicles from Amphiphilic Graphene Quantum Dots
Authors: Nandi Sukhendu , Kolusheva Sofiya , Malishev Ravit , Trachtenberg Alexander , Vinod T. P. , Jelinek Raz 
Published: March 2015

AbstractGraphene quantum dots (GQDs) have attracted considerable interest due to their unique physicochemical properties and various applications. For the first time it is shown that GQDs surface‐functionalized with hydrocarbon chains (i.e., amphiphilic GQDs) self‐assemble into unilamellar spherical vesicles in aqueous solution. The amphiphilic GQD vesicles exhibit multicolor luminescence that can be readily exploited for membrane studies by fluorescence spectroscopy and microscopy. The GQD vesicles were used for microscopic analysis of membrane interactions and disruption by the peptide beta‐amyloid.
The Mechanism of CO2 Insertion into Iridium(I) Hydroxide and Alkoxide Bonds: A Kinetics and Computational Study
Authors: Truscott Byron J. , Kruger Hedi , Webb Paul B. , Bühl Michael , Nolan Steven P. 
Published: March 2015

AbstractThe facile insertion of CO2 into iridium(I) hydroxide, alkoxide, and amide bonds was recently reported. In particular, [Ir(cod)(IiPr)(OH)] (IiPr=1,3‐bis(isopropyl)imidazol‐2‐ylidene) reacted with CO2 in solution and in the solid state in a matter of minutes to give the novel [{Ir(cod)(IiPr)}2(μ‐κ1O:κ2O,O‐CO3)] complex. In the present study, this reaction is probed using kinetics and theoretical studies, which enabled us to analyse its facile nature and to fully elucidate the reaction mechanism with excellent correlation between the two methods.
Modular Stereoselective Synthesis of (1→2)‐C‐Glycosides based on the sp2–sp3 Suzuki–Miyaura Reaction
Authors: Oroszova Beata , Choutka Jan , Pohl Radek , Parkan Kamil 
Published: March 2015

AbstractThis work reports a modular and rapid approach to the stereoselective synthesis of a variety of α‐ and β‐(1→2)‐linked C‐disaccharides. The key step is a Ni‐catalyzed cross‐coupling reaction of D‐glucal pinacol boronate with alkyl halide glycoside easily prepared from commercially available D‐glucal. The products of this sp2–sp3 cross‐coupling reaction can be converted to glucopyranosyl, mannopyranosyl, or 2‐deoxy‐glucopyranosyl C‐mannopyranosides by one‐ or two‐step stereoselective oxidative–reductive transformations. To the best of our knowledge, we demonstrated the first synthetic application of a challenging sp2–sp3 Suzuki‐Miyaura cross‐coupling reaction in carbohydrate chemistry.
Non‐Aqueous Sol–Gel Synthesis of Ultra Small Persistent Luminescence Nanoparticles for Near‐Infrared In Vivo Imaging
Authors: Teston Eliott , Richard Sophie , Maldiney Thomas , Lièvre Nicole , Wang Guillaume Yangshu , Motte Laurence , Richard Cyrille , Lalatonne Yoann 
Published: March 2015

AbstractUltra‐small ZnGa2O4:Cr3+ nanoparticles (6 nm) that exhibit near‐infrared (NIR) persistent luminescence properties are synthesized by using a non‐aqueous sol–gel method assisted by microwave irradiation. The nanoparticles are pegylated, leading to highly stable dispersions under physiological conditions. Preliminary in vivo studies show the high potential for these ultra‐small ZnGa2O4:Cr3+ nanoparticles to be used as in vivo optical nanotools as they emit without the need for in situ excitation and, thus, avoid the autofluorescence of tissues.
MnO2 Nanosheets Grown on Nitrogen‐Doped Hollow Carbon Shells as a High‐Performance Electrode for Asymmetric Supercapacitors
Authors: Li Lei , Li Rumin , Gai Shili , Ding Shujiang , He Fei , Zhang Milin , Yang Piaoping 
Published: March 2015

AbstractA hierarchical hollow hybrid composite, namely, MnO2 nanosheets grown on nitrogen‐doped hollow carbon shells (NHCSs@MnO2), was synthesized by a facile in situ growth process followed by calcination. The composite has a high surface area (251 m2g−1) and mesopores (4.5 nm in diameter), which can efficiently facilitate transport during electrochemical cycling. Owing to the synergistic effect of NHCSs and MnO2, the composite shows a high specific capacitance of 306 F g−1, good rate capability, and an excellent cycling stability of 95.2 % after 5000 cycles at a high current density of 8 A g−1. More importantly, an asymmetric supercapacitor (ASC) assembled by using NHCSs@MnO2 and activated carbon as the positive and negative electrodes exhibits high specific capacitance (105.5 F g−1 at 0.5 A g−1 and 78.5 F g−1 at 10 A g−1) with excellent rate capability, achieves a maximum energy density of 43.9 Wh kg−1 at a power density of 408 W kg−1, and has high stability, whereby the ASC retains 81.4 % of its initial capacitance at a current density of 5 A g−1 after 4000 cycles. Therefore, the NHCSs@MnO2 electrode material is a promising candidate for future energy‐storage systems.
Computational Mechanistic Elucidation of the Intramolecular Aminoalkene Hydroamination Catalysed by Iminoanilide Alkaline‐Earth Compounds
Authors: Tobisch Sven 
Published: March 2015

AbstractA comprehensive computational exploration of plausible alternative mechanistic pathways for the intramolecular hydroamination (HA) of aminoalkenes by a recently reported class of kinetically stabilised iminoanilide alkaline‐earth silylamido compounds [{N^N}Ae{N(SiMe3)2}⋅(thf)n] ({N^N}=iminoanilide; Ae=Ca, Sr, Ba) is presented. On the one hand, a proton‐assisted concerted NC/CH bond‐forming pathway to afford the cycloamine in a single step can be invoked and on the other hand, a stepwise σ‐insertive pathway that involves a fast, reversible migratory olefin 1,2‐insertion step linked to a less rapid, irreversible metalC azacycle tether σ‐bond aminolysis. Notably, these alternative mechanistic avenues are equally consistent with reported key experimental features. The present study, which employs a thoroughly benchmarked and reliable DFT methodology, supports the prevailing mechanism to be a stepwise σ‐insertive pathway that sees an initial conversion of the {N^N}Ae silylamido into the catalytically competent {N^N}Ae amidoalkene compound and involves thereafter facile and reversible insertive NC bond‐forming ring closure, linked to irreversible intramolecular AeC tether σ‐bond aminolysis at the transient {N^N}Ae alkyl intermediate. Turnover‐limiting protonolysis accounts for the substantial primary kinetic isotope effect observed; its DFT‐derived barrier satisfactorily matches the empirically determined Eyring parameter and predicts the decrease in rate observed across the series Ca>Sr>Ba correctly. Non‐competitive kinetic demands militate against the operation of the concerted proton‐assisted pathway, which describes NC bond‐forming ring closure triggered by concomitant amino proton delivery at the CC linkage evolving through a multi‐centre TS structure. Valuable insights into the catalytic structure–activity relationships are unveiled by a detailed comparison of [{N^N}Ae(NHR)] catalysts. Moreover, the intriguingly opposite trends in reactivity observed in intramolecular (Ca>Sr>Ba) and intermolecular (Ca<Sr<Ba) HA catalysis for the studied family of iminoanilide alkaline‐earth amido catalysts are rationalised.
Biomolecular Assemblies Combining Two Orthogonal Copper‐Mediated Ligations in a One‐Pot Reaction
Authors: Grassin Adrien , Claron Michaël , Boturyn Didier 
Published: March 2015

AbstractThe access to multifunctional biomolecular compounds involves multistep reactions usually with a complicated protection scheme and lengthy separation processes. The development of a strategy combining several orthogonal ligations is highly desirable. Herein, we introduce a new method that involves two orthogonal copper‐mediated ligations of azide with alkyne, and amine with thioacid. We established compatible conditions to carry out molecular assemblies of three different chemical components in a single one‐pot reaction. The effectiveness of the method was demonstrated in the synthesis of biomolecular compounds that are known to target tumor tissue. The simple reaction conditions suggest that this strategy of combining several orthogonal ligations could have wide potential for the chemical synthesis of complex macromolecules.
Stabilization of a Bimolecular Triplex by 3′‐S‐Phosphorothiolate Modifications: An NMR and UV Thermal Melting Investigation
Authors: Evans Kathryn , Bhamra Inder , Wheelhouse Richard T. , Arnold John R. P. , Cosstick Richard , Fisher Julie 
Published: March 2015

AbstractTriplexes formed from oligonucleic acids are key to a number of biological processes. They have attracted attention as molecular biology tools and as a result of their relevance in novel therapeutic strategies. The recognition properties of single‐stranded nucleic acids are also relevant in third‐strand binding. Thus, there has been considerable activity in generating such moieties, referred to as triplex forming oligonucleotides (TFOs). Triplexes, composed of Watson–Crick (W–C) base‐paired DNA duplexes and a Hoogsteen base‐paired RNA strand, are reported to be more thermodynamically stable than those in which the third strand is DNA. Consequently, synthetic efforts have been focused on developing TFOs with RNA‐like structural properties. Here, the structural and stability studies of such a TFO, composed of deoxynucleic acids, but with 3′‐S‐phosphorothiolate (3′‐SP) linkages at two sites is described. The modification results in an increase in triplex melting temperature as determined by UV absorption measurements.1H NMR analysis and structure generation for the (hairpin) duplex component and the native and modified triplexes revealed that the double helix is not significantly altered by the major groove binding of either TFO. However, the triplex involving the 3′‐SP modifications is more compact. The 3′‐SP modification was previously shown to stabilise G‐quadruplex and i‐motif structures and therefore is now proposed as a generic solution to stabilising multi‐stranded DNA structures.
Mesoporous Carbon Nitride‐Tungsten Oxide Composites for Enhanced Photocatalytic Hydrogen Evolution
Authors: Kailasam Kamalakannan , Fischer Anna , Zhang Guigang , Zhang Jinshui , Schwarze Michael , Schröder Marc , Wang Xinchen , Schomäcker Reinhard , Thomas Arne 
Published: March 2015

AbstractComposites of mesoporous polymeric carbon nitride and tungsten(VI) oxide show very high photocatalytic activity for the evolution of hydrogen from water under visible light and in the presence of sacrificial electron donors. Already addition of very small amounts of WO3 yields up to a twofold increase in the efficiency when compared to bulk carbon nitrides and their composites and more notably even to the best reported mesoporous carbon nitride‐based photocatalytic materials. The higher activity can be attributed to the high surface area and synergetic effect of the carbon nitrides and the WO3 resulting in improved charge separation through a photocatalytic solid‐state Z‐scheme mechanism.
Rule Construction and Execution for Root Cause Analysis
Authors: Kudo Yutaka , Morimura Tomohiro , Sugauchi Kiminori , Masuishi Tetsuya , Komoda Norihisa 
Published: March 2015

SUMMARYWe developed a root cause analysis (RCA) system for an enterprise IT system environment. In this paper, we propose a rule‐construction method that builds analysis rule data objects from general analysis rules and the topology information of the actual target IT environment. Using this method, the IT administrator can use the RCA system without any manual rule modifications. For the execution of the analysis, we introduce the certainty factor to realize robust analysis when the order and reachability of a fault event cannot be guaranteed.
Stabilization of Power Supply for the Shinkansen with Power Converters
Authors: KUNOMURA KEN , YOKOSUKA MORIYUKI , ARAI SEIICHI , KUBOTA TOMOYA 
Published: March 2015

SUMMARYIn the Tokaido Shinkansen, rolling stock types have been unified as an inverter controlled type, which was introduced after Series 300. As a result, the input power factor of the main converter used in the rolling stock has been controlled to 1. In accordance with this change, the role of reactive compensation of static var compensators (SVC) has shifted from the load power of trains to the power consumed by the reactance in the electrical power system. Therefore, when taking into consideration the aging of power converters, it is time to reassess their layout and the configuration for the future of the Tokaido Shinkansen. We reassessed the equipment configuration, capacity, and layout of power converters and verified the impact on the stabilization of the power supply when introducing self‐commutated power converters.
Direct Determination of Trace Dopamine in an Ascorbic Acid Solution at a Bare Glassy Carbon Electrode Using Differential Pulse Voltammetry
Authors: Sun Lijian , Chen Jing , Zhao Fangmin , Liu Na , Zhang Yingqiu , Jia Jianbo , Wang Jianguo 
Published: March 2015

AbstractIt is difficult to monitor dopamine (DA) accurately with a bare glassy carbon electrode because of the interference of ascorbic acid (AA). In this paper, a method for the determination of DA in an AA solution using differential pulse voltammetry was established. Because AA loses its electrochemical activity after being oxidized, hydrogen peroxide was used to oxidize AA, and the interference of AA was completely eliminated. As a result, trace DA could be directly determined in the AA solution with a bare glassy carbon electrode. When trace DA was determined in a 1.0 mmol L−1 AA solution, there was a wide linear range from 3.0×10−8 mol L−1 to 1.0×10−5 mol L−1. The application of this method was demonstrated by the selective measurement of DA in an injection without pretreatment.
High Sensitive Microsensor Based on Organic‐Inorganic Composite for Two‐Dimensional Mapping of H2O2 by SECM
Authors: Justino Danielle Diniz , Torres Isabel Lourenço , de Cássia Silva Luz Rita , Damos Flavio Santos 
Published: March 2015

AbstractThe present work describes the development of a selective, sensitive and stable sensing microsensor for scanning electrochemical microscopy (SECM) to measure H2O2 during electrochemical reduction of oxygen. The microsensor is based on graphene and Poly(3,4‐ethylenedioxythiophene) composite as support to iron (III) hexacyanoferrate (II) (PEDOT/graphene/FeIII4[FeII(CN)6]3 microsensor). The electrochemical properties of the PEDOT/graphene/FeIII4[FeII(CN)6]3 microsensor were investigated by cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM). The PEDOT/graphene/FeIII4[FeII(CN)6]3 microsensor showed an excellent electrocatalytic activity toward hydrogen peroxide (H2O2) reduction with a diminution of the overpotential of about 500 mV in comparison to the process at a bare gold microelectrode. The microsensor presented excellent performance for two dimensional mapping of H2O2 by SECM in 0.1 mol L−1 phosphate buffer solution (pH 7.0). Under optimized conditions, a linear response range from 1 up to 1000 µmol L−1 was obtained with a sensitivity of 0.08 nA L µmol−1 and limit of detection of 0.5 µmol L−1.
Hydrothermal Growth of Ag‐Doped ZnO Nanoparticles on Electrospun Cellulose Nanofibrous Mats for Catechol Detection
Authors: Fu Jiapeng , Pang Zengyuan , Yang Jie , Yang Zhanping , Cao Jianhua , Xu Yang , Huang Fenglin , Wei Qufu 
Published: March 2015

AbstractWe fabricated a novel hierarchical composite mat composed of electrospun cellulose nanofibers decorated with Ag‐doped ZnO (Ag‐ZnO) nanoparticles and further demonstrated its potential application as the efficient laccase (Lac) biosensor substrate material. The cyclic voltammograms revealed that the Ag‐ZnO/cellulose nanofibrous mat provided an excellent microenvironment for Lac immobilization and benefited direct electron transfer of Lac. The fabricated Lac/Ag‐ZnO/cellulose/GCE exhibited a highly sensitive detection of catechol with a wide linear range from 0.995 to 811 µM and a low detection limit of 0.205 µM. The results indicated that Ag‐ZnO/cellulose nanofibers were the promising nanostructured materials for the construction of different biosensors.
A Nitrite Electrochemical Sensor Based on Boron‐Doped Diamond Planar Electrochemical Microcells Modified with a Monolacunary Silicotungstate Polyoxoanion
Authors: Sahraoui Yosra , Sbartai Amel , Chaliaa Sana , Maaref Abderrazak , Haddad Amor , Jaffrezic‐Renault Nicole 
Published: March 2015

AbstractA new boron doped diamond microcells (BDD) was modified, for rapid, selective and highly sensitive determination of nitrite, using a coating film of polyoxometalates (POMs), formed by cyclic voltammetry on the molecular p‐phenylenediamine (PPD) functionalized BDD. The scanning electron microscopy (SEM) technique was used to examine the morphology of (PPD/SiW11) modified (BDD) electrode. It was found that (SiW11) layer was uniformly formed on the electrode surface. It was observed that (BDD/PPD/SiW11) showed excellent electrocatalytic activities towards nitrite ion. Under the selected conditions, the anodic peak maximum at −0.6 V was linear versus nitrite concentration in the 40 µM–4 mM range, and the detection limit obtained was 20 µM. The newly developed electrode has been successfully applied to the determination of nitrite content in real river water samples.
Uric Acid Determination by Adsorptive Stripping Voltammetry on Multiwall Carbon Nanotubes Based Screen‐Printed Electrodes
Authors: Fanjul‐Bolado Pablo , Santos David Hernández , Montoya Virgilio Macho , Costa‐García Agustín 
Published: March 2015

AbstractA sensitive electroanalytical methodology for the determination of uric acid in real samples using adsorptive voltammetry at a multiwalled carbon nanotubes (MWCNT) modified screen printed electrode (SPCE) is presented. Adsorption of uric acid takes place at open circuit potential at an optimized pH 5.0. Studies about the effect of accumulation time and scan rate on the analytical signal were developed and confirm the adsorption nature of the electrodic process. Quantitative analysis of uric acid by using its oxidation process at +0.18 V (vs. an Ag pseudoreference electrode) was carried out with an accumulation time of 5 min. Thus, a linear voltammetric based reproducible determination of uric acid (RSD 5 %) in the range 1–100 µM was obtained. The method was then successfully used for the determination of uric acid in real clinical samples of urine without detection of interferences. The proposed methodology only requires a dilution of the real sample and present advantages as low cost and easy handling for non specialized technicians.
Enhanced Performance of Lithium‐Ion Batteries with Copper Oxide Microspheres @ Graphene Oxide Micro/Nanocomposite Electrodes
Authors: Xu Yi‐Tao , Guo Ying , Jiang Hong , Xie Xiao‐Bin , Zhao Bo , Zhu Peng‐Li , Fu Xian‐Zhu , Sun Rong , Wong Ching‐Ping 
Published: March 2015

AbstractCuO microspheres are obtained from thermal oxidation of Cu2O microspheres. A facile approach directed by electrostatic self‐assembly is used to fabricate graphene oxide wrapped CuO (CuO@GO). GO nanosheets directly used in batteries could reduce the preparation cost and pollution relative to reduced graphene oxide. As coating layers, GO could be electrochemically reduced to graphene in situ to obtain an additional 3D conductive network. The CuO@GO core–shell micro/nanocomposites exhibit significantly improved lithium storage capacity and cycling performance as compared to CuO microspheres or the physical mixture of CuO microspheres and GO nanosheets (CuO–GO‐PM). Under a current density of 100 mA g−1, CuO@GO retains a high discharge capacity of approximately 590 mAh g−1 for up to 50 cycles. After 200 cycles at a current density of 1000 mA g−1, the discharge capacity of the CuO@GO is approximately 313 mAh g−1, which is approximately 3 times larger than that of the CuO microspheres and CuO–GO‐PM.
Discrete Biogeography Based Optimization for Feature Selection in Molecular Signatures
Authors: Liu Bo , Tian Meihong , Zhang Chunhua , Li Xiangtao 
Published: March 2015

AbstractBiomarker discovery from high‐dimensional data is a complex task in the development of efficient cancer diagnoses and classification. However, these data are usually redundant and noisy, and only a subset of them present distinct profiles for different classes of samples. Thus, selecting high discriminative genes from gene expression data has become increasingly interesting in the field of bioinformatics. In this paper, a discrete biogeography based optimization is proposed to select the good subset of informative gene relevant to the classification. In the proposed algorithm, firstly, the fisher‐markov selector is used to choose fixed number of gene data. Secondly, to make biogeography based optimization suitable for the feature selection problem; discrete migration model and discrete mutation model are proposed to balance the exploration and exploitation ability. Then, discrete biogeography based optimization, as we called DBBO, is proposed by integrating discrete migration model and discrete mutation model. Finally, the DBBO method is used for feature selection, and three classifiers are used as the classifier with the 10 fold cross‐validation method. In order to show the effective and efficiency of the algorithm, the proposed algorithm is tested on four breast cancer dataset benchmarks. Comparison with genetic algorithm, particle swarm optimization, differential evolution algorithm and hybrid biogeography based optimization, experimental results demonstrate that the proposed method is better or at least comparable with previous method from literature when considering the quality of the solutions obtained.
Shock Tube Effect Inside a Pyrotechnic Igniter
Authors: Buttigieg Gavin A. , Paine Gregory H. , Hsiao Ralph C. 
Published: March 2015

AbstractAn output closure is a critical component of a pyrotechnic igniter. It controls the heat transfer duration of initiation train, stress loading on the propellant grain, and the pressure drop during closure deployment. Normally the pressure profiles calculated by a quasi‐static interior ballistics code are adequate for igniter design evaluation. But following a case of premature closure deployment in which the propellant failed to ignite, the authors discovered that the design geometry mimicked that of a shock tube. The shock tube effect occurred whenever the high‐temperature gases of the initiator were rapidly discharged into a long conduit. The shock resultant from the initiator opened the closure prior to ignition of the ignition aid. In this paper, we report results from both quasi‐static computations for static pressure and time‐dependent simulations for dynamic pressure. Designers need to consider both static and dynamic pressure when devices have a sudden high‐pressure gas released into a conduit.