bluuebunny/crossref_metadata_2025_split huggingface dataset:
Volume‐to‐creatinine clearance ratio in patients undergoing coronary angiography with or without percutaneous coronary intervention: Implications of varying definitions of contrast‐induced nephropathy
Authors: Capodanno Davide , Ministeri Margherita , Cumbo Silvia , Dalessandro Veronica , Tamburino Corrado 
Published: August 2013

ObjectivesWhether predicting the risk of early serum creatinine rise using the ratio of the volume of contrast media administered to the estimated creatinine clearance (V/CrCl) is applicable to the broader definition of contrast‐induced nephropathy (CIN) (≥0.5 mg/dL absolute and/or 25% relative increase from baseline serum creatinine) is unknown.BackgroundA V/CrCl ≥4 has been proven to predict the risk of ≥0.5 mg/dL postprocedural absolute rise in serum creatinine.MethodsA total of 722 patients undergoing coronary angiography ± percutaneous coronary intervention (PCI) between March 2011 and October 2011 with paired serum creatinine determinations at preprocedure and within 72‐hr postprocedure were analyzed. The V/CrCl ratio was calculated by dividing the volume of contrast received by the patient's creatinine clearance. CIN using different definitions was termed as CINnarrow (rise in serum creatinine ≥0.5 mg/dL) and CINbroad (rise in serum creatinine ≥0.5 mg/dL and/or ≥25% increase in baseline serum creatinine).ResultsThe mean age was 66 ± 11 years and the mean baseline serum creatinine was 1.1 ± 0.8 mg/dL. Patients with V/CrCl ≥4 were significantly older and more frequently underwent ad hoc PCI compared with those with V/CrCl <4. CINnarrow and CINbroad were observed in 13 versus 3% (P < 0.001) and 23 versus 11% (P < 0.001) of patients with or without V/CrCl ≥4, respectively. After statistical adjustment, a V/CrCl ratio ≥4 remained significantly associated with the risk of both CINnarrow [adjusted OR 3.5, 95% confidence intervals (95% CI) 1.7–7.3; P < 0.001] and CINbroad (adjusted OR 2.5, 95% 1.6–3.9; P < 0.001).ConclusionsA volume‐to‐creatinine clearance ratio ≥4 significantly predicts the risk of early postprocedural rise in serum creatinine regardless of the CIN definition adopted. © 2013 Wiley Periodicals, Inc.
Phosphate‐Doped Carbon Black as Pt Catalyst Support: Co‐catalytic Functionality for Dimethyl Ether and Methanol Electro‐oxidation
Authors: Yin Min , Huang Yunjie , Li Qingfeng , Jensen Jens Oluf , Cleemann Lars N. , Zhang Wei , Bjerrum Niels J. , Xing Wei 
Published: August 2013

AbstractNiobium‐phosphate‐doped (NbP‐doped) carbon blacks were prepared as the composite catalyst support for Pt nanoparticles. Functionalities of the composite include intrinsic proton conductivity, surface acidity, and interfacial synergistic interactions with methanol and dimethyl ether (DME). The supported Pt catalysts show significant improvement in catalytic activity towards the direct oxidation of methanol and DME, attributable to the enhanced adsorption and dehydrogenation of methanol and DME, as well as the presence of activated OH species in the catalysts. The latter is demonstrated to facilitate the removal of CO intermediates formed during the oxidation reactions.
General Synthesis and Physicochemical Characterisation of a Series of Peptide‐Mimic Lysine‐Based Amino‐Functionalised Lipids
Authors: Wölk Christian , Drescher Simon , Meister Annette , Blume Alfred , Langner Andreas , Dobner Bodo 
Published: August 2013

AbstractA series of novel malonic acid diamides (second generation) with two long hydrophobic alkyl chains and an alkaline polar head group was synthesised and characterised as a new class of amino‐functionalised lipids. These peptide‐mimic lipids are suitable for polynucleotide transfer. The lipids bear a novel backbone consisting of a lysine unit and a malonic acid unit. Six different head‐group structures, which vary in size and number of amino groups that can be protonated, were attached to the backbone structure. Furthermore, different alkyl chains were used to build the lipophilic part (namely tetradecyl, hexadecyl, and oleyl). Phase transitions of the new compounds in aqueous dispersions at pH 10 were analysed and discussed in terms of head group and alkyl chain variations. The shape and size of the formed aggregates of selected lipid dispersions were investigated by dynamic light scattering and transmission electron microscopy.
Conductive, Monodisperse Polyaniline Nanofibers of Controlled Length Using Well‐Defined Cylindrical Block Copolymer Micelles as Templates
Authors: McGrath Nina , Patil Avinash J. , Watson Scott M. D. , Horrocks Benjamin R. , Faul Charl F. J. , Houlton Andrew , Winnik Mitchell A. , Mann Stephen , Manners Ian 
Published: August 2013

AbstractStable colloidal dispersions of polyaniline (PAni) nanofibers with controlled lengths from about 200 nm–1.1 μm and narrow length distributions (Lw/Ln<1.04; Lw=weight average micelle length, Ln=number average micelle length) were prepared through the template‐directed synthesis of PAni using monodisperse, solution‐self‐assembled, cylindrical, block copolymer micelles as nanoscale templates. These micelles were prepared through a crystallization‐driven living self‐assembly method from a poly(ferrocenyldimethylsilane)‐b‐poly(2‐vinylpyridine) block copolymer (PFS25‐b‐P2VP425). This material was initially self‐assembled in iPrOH to form cylindrical micelles with a crystalline PFS core and a P2VP corona and lengths of up to several micrometers. Sonication of this sample then yielded short cylinders with average lengths of 90 nm and a broad length distribution (Lw/Ln=1.32). Cylindrical micelles of PFS25‐b‐P2VP425 with controlled lengths and narrow length distributions (Lw/Ln<1.04) were subsequently prepared using thermal treatment at specific temperatures between 83.5 and 92.0 °C using a 1D self‐seeding process. These samples were then employed in the template‐directed synthesis of PAni nanofibers through a two‐step procedure, where the micellar template was initially stabilised by deposition of an oligoaniline coating followed by addition of a polymeric acid dopant, resulting in PAni nanofibers in the emeraldine salt (ES) state. The ES–PAni nanofibers were shown to be conductive by scanning conductance microscopy, whereas the precursor PFS25‐b‐P2VP425 micelle templates were found to be dielectric in character.
Tuning the Dispersibility of Carbon Nanostructures from Organophilic to Hydrophilic: Towards the Preparation of New Multipurpose Carbon‐Based Hybrids
Authors: Georgakilas Vasilios , Kouloumpis Antonios , Gournis Dimitrios , Bourlinos Athanasios , Trapalis Christos , Zboril Radek 
Published: August 2013

AbstractThe hydroxyphenyl derivatives of carbon nanostructures (graphene and carbon nanotubes) can be easily transformed into highly organophilic or hydrophilic derivatives by using the ionic interactions between the phenolic groups and oleylamine or tetramethylammonium hydroxide, respectively. The products were finely dispersed in homo‐polymers or block co‐polymers to create homogeneous carbon‐based nanocomposites and were used as nanocarriers for the dispersion and protection of strongly hydrophobic compounds, such as large aromatic chromophores or anticancer drugs in aqueous solutions.
High Charge Delocalization and Conjugation in Oligofuran Molecular Wires
Authors: Gidron Ori , Diskin‐Posner Yael , Bendikov Michael 
Published: August 2013

AbstractThe extent of charge delocalization and of conjugation in oligofurans and oligothiophenes was studied by using mixed valence systems comprising oligofurans and oligothiophenes capped at both ends by ferrocenyl redox units. Using electrochemical, spectral, and computational tools, we find strong charge delocalization in ferrocene‐capped oligofurans which was stronger than in the corresponding oligothiophene systems. Spectroscopic studies suggest that the electronic coupling integral (Hab) is roughly 30–50 % greater for oligofuran‐bridged systems, indicating better energy matching between ferrocene units and oligofurans. The distance decay constant (damping factor), β, is similar for oligofurans (0.066 A−1) and oligothiophenes (0.070 A−1), which suggests a similar extent of delocalization in the bridge, despite the higher HOMO–LUMO gap in oligofurans. Computational studies indicate a slightly larger extent of delocalization in furan‐bridged systems compared with thiophene‐bridged systems, which is consistent with oligofurans being significantly more rigid and less aromatic than oligothiophenes. High charge delocalization in oligofurans, combined with the previously reported strong fluorescence, high mobility, and high rigidity of oligofuran‐based materials makes them attractive candidates for organic electronic applications.
Nanosilver‐Decorated TiO2 Nanofibers Coated with a SiO2 Layer for Enhanced Light Scattering and Localized Surface Plasmons in Dye‐Sensitized Solar Cells
Authors: Hwang Sun Hye , Roh Jongmin , Jang Jyongsik 
Published: August 2013

AbstractEnhanced harvesting of visible light is vital to the development of highly efficient dye‐sensitized solar cells (DSSCs). Nanosilver‐decorated TiO2 nanofibers (Ag@TiO2 NFs) were synthesized by depositing chemically reduced Ag ions onto the surface of electrospun TiO2 nanofibers (TiO2 NFs). The prepared Ag@TiO2 NFs were coated with SiO2 (SiO2@Ag@TiO2 NFs) by using PVP as coupling agent for protecting corrosion of Ag nanoparticle by I−/${{\rm I}{{- \hfill \atop 3\hfill}}}$ solution. The fabricated SiO2@Ag@TiO2 NFs demonstrated a synergistic effect of light scattering and surface plasmons, leading to an enhanced light absorption. Moreover, an anode consisting of SiO2@Ag@TiO2 NFs incorporating TiO2 nanoparticles (NPs) increased light harvesting without substantially sacrificing dye attachment. The power conversion efficiency increased from 6.8 to 8.7 % for a thick film (10 μm), that is, 28 %. These results suggest that SiO2@Ag@TiO2 NFs are promising materials for enhanced light absorption in dye‐sensitized solar cells.
Cyclometalation of Aryl‐Substituted Phosphinines through CH‐Bond Activation: A Mechanistic Investigation
Authors: Broeckx Leen E. E. , Güven Sabriye , Heutz Frank J. L. , Lutz Martin , Vogt Dieter , Müller Christian 
Published: August 2013

AbstractA series of 2,4,6‐triarylphosphinines were prepared and investigated in the base‐assisted cyclometalation reaction using [Cp*IrCl2]2 (Cp*=1,2,3,4,5‐pentamethylcyclopentadienyl) as the metal precursor. Insight in the mechanism of the CH bond activation of phosphinines as well as in the regioselectivity of the reaction was obtained by time‐dependent 31P{1H} NMR spectroscopy. At room temperature, 2,4,6‐triarylphosphinines instantaneously open the Ir‐dimer and coordinate in an η1‐fashion to the metal center. Upon heating, a dissociation step towards free ligand and an Ir‐acetate species is observed and proven to be a first‐order reaction with an activation energy of ΔEA=56.6 kJ mol−1 found for 2,4,6‐triphenylphosphinine. Electron‐donating substituents on the ortho‐phenyl groups of the phosphorus heterocycle facilitate the subsequent cyclometalation reaction, indicating an electrophilic CH activation mechanism. The cyclometalation reaction turned out to be very sensitive to steric effects as even small substituents can have a large effect on the regioselectivity of the reaction. The cyclometalated products were characterized by means of NMR spectroscopy and in several cases by single‐crystal X‐ray diffraction. Based on the observed trends during the mechanistic investigation, a concerted base‐assisted metalation–deprotonation (CMD) mechanism, which is electrophilic in nature, is proposed.
Use of Cleavable Coordinating Rings as Protective Groups in the Synthesis of a Rotaxane with an Axis that Incorporates More Chelating Groups Than Threaded Macrocycles
Authors: Joosten Antoine , Trolez Yann , Heitz Valérie , Sauvage Jean‐Pierre 
Published: August 2013

AbstractA new methodology allowing preparation of a linear “unsaturated” [3]rotaxane consisting of an axis incorporating more coordination sites than threaded rings was developed. It was based on the preliminary synthesis of a “saturated” [5]rotaxane consisting of a four‐chelating site axis threaded through four macrocyclic components, two of them being cleavable rings incorporating a lactone function and the two others being “secure” non‐cleavable rings. The stoppering reaction was based on click chemistry. Subsequently, cleavage and removal of the two lactone‐containing macrocycles from the [5]rotaxane in basic medium afforded the desired “unsaturated” [3]rotaxane in quantitative yield.
Benzofurazane as a New Redox Label for Electrochemical Detection of DNA: Towards Multipotential Redox Coding of DNA Bases
Authors: Balintová Jana , Plucnara Medard , Vidláková Pavlína , Pohl Radek , Havran Luděk , Fojta Miroslav , Hocek Michal 
Published: August 2013

AbstractBenzofurazane has been attached to nucleosides and dNTPs, either directly or through an acetylene linker, as a new redox label for electrochemical analysis of nucleotide sequences. Primer extension incorporation of the benzofurazane‐modified dNTPs by polymerases has been developed for the construction of labeled oligonucleotide probes. In combination with nitrophenyl and aminophenyl labels, we have successfully developed a three‐potential coding of DNA bases and have explored the relevant electrochemical potentials. The combination of benzofurazane and nitrophenyl reducible labels has proved to be excellent for ratiometric analysis of nucleotide sequences and is suitable for bioanalytical applications.
Tandem Synthesis of Benzo[b]carbazoles and Their Photoluminescent Properties
Authors: Xing Yanpeng , Hu Binbin , Yao Qijun , Lu Ping , Wang Yanguang 
Published: August 2013

Abstract5 H‐Benzo[b]carbazoles were prepared through a tandem reaction between 2‐ethynyl‐N‐triphenylphosphoranylidene anilines and α‐diazoketones through ketenimine intermediates in moderate‐to‐good yields. By using this approach, benzo[b]benzo[5,6]indolo[3,2‐h]carbazoles, fluoreno[9,1‐ab]carbazoles, and fluoreno[9,1‐ab]fluoreno[1′,9′:5,6,7]indolo[3,2‐h]carbazoles were constructed in one pot. Moreover, the resulting products emitted light within the range 410–521 nm, with quantum yields of up to 62 %.
A Unique Au–Ag–Au Triangular Motif in a Trimetallic Halonium Dication: Silver Incorporation in a Gold(I) Catalyst
Authors: Zhu Yuyang , Day Cynthia S. , Zhang Lin , Hauser Katarina J. , Jones Amanda C. 
Published: August 2013

AbstractAs a result of explorations into the solution chemistry of silver/gold mixtures, a unique diphosphine trimetallic chloronium dication was discovered that incorporates silver–arene chelation and a triangular mixed gold/silver core in the solid state. Notably, it was isolated from a Celite prefiltered solution initially thought to be silver‐free. The crystal structure also incorporates the coordination to silver of one fluorine atom of one SbF6− counterion. The structure was compared to two new, but well‐precedented, phosphine digold chloride cations. DFT calculations supported significant silver–halide and silver–arene interactions in the mixed gold/silver complex and metallophilic interactions in all three complexes. Comparison of computed data revealed that the ωB97X‐D functional, which has a long‐range corrected hybrid with atom–atom dispersion corrections, gave a better fit to the experimental data compared with the PBE0 functional, which has previously failed to capture aurophilic interactions. Preliminary studies support the presence of the mixed gold/silver structure in solution.
Effects of the 2011 Tohoku‐Oki M9.0 Earthquake on the Crustal Movement in the Shandong Area Derived from GPS Data
Authors: Hai‐Tao YIN , Wei‐Jun GAN , Bei HUANG , Gen‐Ru XIAO , Jie LI , Cheng‐Lin ZHU 
Published: August 2013

AbstractBased on the Shandong Crustal Movement GPS Observation Network, combining the global GPS data provided by IGS, we calculate the effects of 2011 Tohoku‐Oki M9.0 earthquake on the Shandong area and obtain the real motion tracks of stations in this region. The results show that: the maximum amplitude is more than 0.2 m at the GPS stations in Shandong during the earthquake, the wave movement lasted about 160 s. The direction of co‐seismic displacement is nearly south‐easterly, and the maximum displacement exceeds 10 mm. The effect of this earthquake on the Shandong area is dominated by horizontal displacement, posing a tension on the Yishu fault zone, on which the tension amplitude of the northern part is obviously larger than the southern part. From the recent movement trend of GPS stations, the blocks of the Shandong area are moving back to west. So we speculate that the movement pattern will return to the former state in about 3∼5 month after the earthquake. This would be of significance for earthquake monitoring in this area.
SaC/C formulations of the all‐pairs N‐body problem and their performance on SMPs and GPGPUs
Authors: Šinkarovs Artjoms , Scholz Sven‐Bodo , Bernecky Robert , Douma Roeland , Grelck Clemens 
Published: August 2013

SUMMARYThis paper describes our experience in implementing the classical N‐body algorithm in SaC and analysing the runtime performance achieved on three different machines: a dual‐processor 8‐core Dell PowerEdge 2950 (a Beowulf cluster node, the reference machine), a quad‐core hyper‐threaded Intel Core‐i7 based system equipped with an NVidia GTX‐480 graphics accelerator and an Oracle Sparc T4‐4 server with a total of 256 hardware threads. We contrast our findings with those resulting from the reference C code and a few variants of it that employ OpenMP pragmas as well as explicit vectorisation. Our experiments demonstrate that the SaC implementation successfully combines a high level of abstraction, very close to the mathematical specification, with very competitive runtimes. In fact, SaC matches or outperforms the hand‐vectorised and hand‐parallelised C codes on all three systems under investigation without the need for any source code modification. Furthermore, only SaC is able to effectively harness the advanced compute power of the graphics accelerator, again by mere recompilation of the same source code. Our results illustrate the benefits that SaC provides to application programmers in terms of coding productivity, source code, and performance portability among different machine architectures, as well as long‐term maintainability in evolving hardware environments. Copyright © 2013 John Wiley & Sons, Ltd.
Thermally Induced Dehydrogenation of Amine–Borane Adducts and Ammonia–Borane by Group 6 Cyclopentadienyl Complexes Having Single and Triple ­Metal–Metal Bonds
Authors: García‐Vivó Daniel , Huergo Estefanía , Ruiz Miguel A. , Travieso‐Puente Raquel 
Published: August 2013

AbstractTreatment of solutions of ammonia–borane (NH3·BH3, AB) with catalytic amounts (5 mol‐%) of the singly bonded dimers [M2Cp2(CO)6] [M = Cr (1a), Mo (1b), W (1c); Cp = cyclopentadienyl] under mild thermal activation (333 K) led to the progressive dehydrogenation of the adduct and quantitative conversions were achieved after 12, 24, and >34 h, respectively. At the initial stages of these reactions (low conversions), the major products were cyclic and branched oligomers of aminoborane (NH2=BH2). However, at longer reaction times (high conversions), the major products were, in all cases, borazine, [HNBH]3, and polyborazylene, [NBHx] (x < 1), whereas other minor products were derived from B–N bond‐cleavage processes. Over the course of these reactions, complexes 1a–c were transformed into the corresponding mononuclear hydrides [MCpH(CO)3] [M = Cr (2a), Mo (2b), W (2c)], which are supposed to be the catalytically active species in these processes, as also supported by similar catalytic activity exhibited by pure samples of the dihydride [Mo2Cp2(H)2(μ‐Ph2PCH2PPh2)(CO)2] (2b′). Under similar conditions, 1a–c were also active catalysts for the dehydrogenation of adducts derived from substituted amines (tBuH2N·BH3 and Me2HN·BH3), although the rate of dehydrogenation was significantly lower than that of AB. This lower activity follows from deprotonation of hydrides 2 by the free amines, which are in turn generated through B–N bond‐cleavage processes. The dehydrogenation products of tBuH2N·BH3 are also derived from oligomerization processes of the corresponding aminoborane (tBuHN=BH2), which in this case was identified in the reaction mixtures, but even at long reaction times, the formation of the borazine‐like product was not complete, and the reaction mixture contained significant amounts of (poorly defined) soluble polymeric materials. For Me2HN·BH3, the major product obtained in all of the reactions was cyclic dimer [Me2N=BH2]2. Similar studies were performed with triply bonded complexes [Mo2Cp2(CO)4] (3b) and [Mo2Cp2(μ‐Ph2PCH2PPh2)(CO)2] (3b′), which displayed similar catalytic activity while remaining essentially unperturbed along the reactions, and these complexes yielded product distributions that were similar to those observed for singly bonded dimers 1a–c.
An Approach to the Synthesis of Functionalized Polycyclic Aromatic Hydrocarbons
Authors: Little Mark , Lan He , Raftery James , Morrison John J. , McDouall Joseph J. W. , Yeates Stephen G. , Quayle Peter 
Published: August 2013

AbstractThe application of a new benzannulation reaction for the regiocontrolled synthesis of functionalized chrysenes is reported. The initial benzannulation and the subsequent halogen displacement reactions are both highly regiospecific, which thereby enables the regiocontrolled synthesis of a variety of 4,10‐disubstituted chrysenes from commercially available 1,5‐dihydroxynaphthalene.
A Comparison of the Gas‐Product‐Release Characteristics from Coal Pyrolysis and Hydrogasification
Authors: Hong Bingqing , Wang Xingjun , Zhou Zhijie , Yu Guangsuo 
Published: August 2013

AbstractCoal pyrolysis and hydrogasification were investigated in a laboratory‐scale pressurized fixed‐bed reactor to examine the effects of temperature, pressure, and catalyst on the gas productivity and yields under different gas atmospheres. The experimental results show that the methane yield is significantly higher under a hydrogen atmosphere. The release rate curve of methane during hydrogasification has three obvious peaks which are the results of coal devolatilization and rapid hydrogenation, the secondary reaction of volatile products, and the slow hydrogenation of residual char, respectively, whereas that of pyrolysis only exhibits the first peak. Changes in temperature and pressure have more remarkable effects on coal hydrogasification than on pyrolysis. Nickel and calcium‐based catalysts influence the rate of CO and CO2 formation but little effect was observed on low‐carbon hydrocarbon production. Potassium‐ and sodium‐based catalysts have a significant effect on the formation of methane under a hydrogen atmosphere. The FTIR spectra show that hydrogen is easily bound to carbon if of potassium‐ and sodium‐based catalysts are used, and CC bond formation is inhibited, which reduces the aggregation of graphite which has very poor activity. Therefore, potassium‐ and sodium‐catalyzed samples could maintain high activities during hydrogasification.
A Dirac Type Condition for Properly Coloured Paths and Cycles
Authors: Lo Allan 
Published: August 2013

AbstractLet c be an edge‐colouring of a graph G such that for every vertex v there are at least different colours on edges incident to v. We prove that G contains a properly coloured path of length 2d or a properly coloured cycle of length at least . Moreover, if G does not contain any properly coloured cycle, then there exists a properly coloured path of length .