bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deposition of silver nanoparticles onto human serum albumin‐functionalised multi‐walled carbon nanotubes
Authors: Rodríguez‐Galván Andrés , Contreras‐Torres Flavio F. , Basiuk Elena V. , Heredia Alejandro , Basiuk Vladimir A. 
Published: February 2012

AbstractTo facilitate the design of carbon nanotube (CNT)‐based hybrid materials, a strategic approach for nanotube dispersion in aqueous media is required. This means that the reactants must exhibit certain selectivity towards both the nanotubes and the solvent medium. The main goal of this study was to prepare new bionanomaterials based on human serum albumin (HSA) and multi‐walled CNTs (MWCNTs), under mild conditions and without covalent modification of the nanotubes. Silver nanoparticles (AgNPs) of a controlled particle size, about 2‐nm diameter, were prepared and directly deposited onto the HSA‐functionalised MWCNTs. The characterisation of AgNP/HSA‐MWCNT hybrids prepared was carried out by scanning tunneling microscopy and transmission electron microscopy (TEM). The presence of the AgNPs was corroborated by elemental chemical analysis using TEM‐coupled energy‐dispersive X‐ray spectroscopy. The density of AgNPs coverage is discussed as a function of HSA concentration, the strength of the reducing agent, and the nature of protein employed (HSA vs. bovine serum albumin and rotavirus nucleocapsid protein VP6). © 2012 Canadian Society for Chemical Engineering
Density, Thermal Expansion and Viscosity of Cholinium‐Derived Ionic Liquids
Authors: Costa Anabela J. L. , Soromenho Mário R. C. , Shimizu Karina , Marrucho Isabel M. , Esperança José M. S. S. , Lopes José N. Canongia , Rebelo Luís Paulo N. 
Published: February 2012

AbstractDensity and viscosity data of the N‐alkyl‐N,N‐dimethyl‐N‐(2‐hydroxyethyl)ammonium bis(trifluoromethylsulfonyl)imide ionic liquids homologous series [N1 1 n 2(OH)][Ntf2] with n=1, 2, 3, 4 and 5 have been measured at atmospheric pressure in the 283<T/K<373 temperature range and the corresponding isobaric thermal expansion coefficients have been calculated. This work studies the effect of increasing the alkyl chain length of the cholinium‐based cation on the density, viscosity and related properties of this family of ionic liquids. A volumetric predictive method based on the effective molar volume of cations and anions is used to estimate the effective molar volume of the different cations present in this study. The results agree with data for other cation families that show a molar volume increment per CH2 group on the alkyl chain of the cation of about 17.2 cm3 mol−1, except for [N1 1 1 2(OH)]+, which exhibits an outlier behaviour. Molecular dynamics simulation results are used to explain the volumetric behaviour along the homologous series from a molecular perspective. The predictive power of group contribution methods for density and viscosity is also tested.
Rapid‐Throughput Competitive Colorimetric Assay Based on Monosaccharide‐Capped Gold Nanoparticles for Detecting Lectin–Protein Interactions
Authors: Tsai Charng‐Sheng , Chen Chao‐Tsen 
Published: February 2012

AbstractIdentification of protein binding partners is one of key challenges in proteomics. A rapid‐throughput competitive colorimetric assay is presented that uses gold nanoparticles capped by sugars such as mannopyranoside (Man–GNPs), N‐acetylglucosamine (GlcNAc–GNPs), glucose (Glc–GNPs), or N‐acetylgalactosamine (GalNAc–GNPs). The assay expediently detects protein–protein interactions in solution, particularly protein–lectin interactions. The competitive assays were conducted in microtiter plates; ten proteins (two glycoproteins and eight lectins) and three sugar‐binding lectins (concanavalin A (ConA), wheat germ agglutinin (WGA), and Ricinus communis agglutinin (RCA120)) were combinatorially arranged in a 30‐well plate, and constant concentrations of the monosaccharide‐capped GNPs (sugar–GNPs) were added to each well. If interactions occurred between the proteins, the sugar–GNPs retained their burgundy color. If no interactions occurred between the proteins, the sugar–GNPs were agglomerated by the corresponding binding lectin, thus producing a blue color. Several new binding pairs were identified for the first time by using this assay, and the binding constants and stoichiometric ratios were determined on the basis of the wavelength shifts. The results were further verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) and fluorescence resonance energy transfer (FRET) spectroscopy. The assay is very sensitive, requiring only nanomolar protein concentrations.
Carbon‐Supported Molybdenum Carbide Catalysts for the Conversion of Vegetable Oils
Authors: Han Junxing , Duan Jinzhao , Chen Ping , Lou Hui , Zheng Xiaoming , Hong Haiping 
Published: February 2012

AbstractOrdered mesoporous carbon (OMC)‐supported molybdenum carbide catalysts were successfully prepared in one pot using a solvent‐evaporation‐induced self‐assembly strategy accompanied by a carbothermal hydrogen reduction reaction. Characterization with nitrogen sorption, small‐angle XRD, and TEM confirmed that the obtained materials had high surface areas, large pore volumes, ordered mesoporous structures, narrow pore size distributions, and uniform dispersions of molybdenum carbide particles. With nitrogen replaced by hydrogen in the carbothermal reduction reaction, the formation temperature of molybdenum carbide could be reduced by more than 100 °C. By changing the amount of molybdenum precursor added from less than 2 % to more than 5 %, molybdenum carbide structures could be easily regulated from Mo2C to MoC. The catalytic performance of OMC‐supported molybdenum carbide catalysts was evaluated by hydrodeoxygenation of vegetable oils. Compared with Mo2C, MoC exhibited high product selectivity and excellent resistance to leaching in the conversion of vegetable oils into diesel‐like hydrocarbons.
New Insights from Microcalorimetry on the FeOx/CNT‐Based Electrocatalysts Active in the Conversion of CO2 to Fuels
Authors: Arrigo Rosa , Schuster Manfred E. , Wrabetz Sabine , Girgsdies Frank , Tessonnier Jean‐Philippe , Centi Gabriele , Perathoner Siglinda , Su Dang Sheng , Schlögl Robert 
Published: February 2012

AbstractFe oxide nanoparticles show enhanced electrocatalytic performance in the reduction of CO2 to isopropanol when deposited on an N‐functionalized carbon nanotube (CNT) support rather than on a pristine or oxidized CNT support. XRD and high‐resolution TEM were used to investigate the nanostructure of the electrocatalysts, and CO2 adsorptive microcalorimetry was used to study the chemical nature of the interaction of CO2 with the surface sites. Although the particles always present the same Fe3O4 phase, their structural anisotropy and size inhomogeneity are consequences of the preparation method of the carbon surface. Two types of chemisorption sites have been determined by using microcalorimetry: irreversible sites (280 kJ mol−1) at the uncoordinated sites of the facets and reversible sites (120 kJ mol−1) at the hydrated oxide surface of the small nanoparticles. N‐Functionalization of the carbon support is advantageous, as it causes the formation of small nanoparticles, which are highly populated by reversible chemisorbing sites. These characteristic features correlate with a higher electrocatalytic performance.
Analysis of multi‐gigabits signal integrity through clock H‐tree
Authors: Eudes Thomas , Ravelo Blaise 
Published: February 2012

ABSTRACTThe H‐tree interconnect network is frequently used for the clock signal sharing in the microelectronic systems. Due to the increase of complexity and operating processing data speed, these interconnect effects can bottleneck the technological advancement. Hence, more accurate interconnect modelling methods are necessary for electronic designers. For this reason, a simple and accurate ultra‐wide band (UWB) model of multilevel distributed interconnection clock trees as a single input multiple outputs (SIMO) system is developed in this article. Very accurate single input single output (SISO) model transfer functions are derived. This method allows the signal integrity prediction regarding the distributed H‐tree characteristics including the source and load impedances. In order to demonstrate the relevance of model developed, analyses of two‐ and three‐level tree networks were performed. Distributed H‐tree realistic devices formed by sub‐millimetre physical length lines for applications for standardised Printed Circuit Board (PCB) interconnections were experimented numerically. The piece of lines constituting the trees is modelled by UWB RLCG network from DC to 8 GHz which takes into account the frequency dispersions and dielectric loss effects. Thus, excellent correlations between simulations and the results from the models proposed were observed both in frequency and time domains regarding 2.5 Gbits/s clock input. Copyright © 2012 John Wiley & Sons, Ltd.
Collective Modes in Classical Mass‐Asymmetric Bilayers
Authors: Golden K. I. , Kalman G. J. , Hartmann P. , Donkó Z. 
Published: February 2012

AbstractUsing the quasi‐localized charge approximation (QLCA), we analyze the effects of asymmetry on the long‐wavelength longitudinal collective mode dispersion in a variety of strongly correlated electronic bilayer liquids, most notably, the mass‐asymmetric electron‐hole bilayer in its Coulomb liquid and dipole liquid phases. We point out the marked differences between the strong coupling (QLCA) and weak coupling (random‐phase‐approximation) descriptions of the way the asymmetry affects the collective mode structure (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection of EPO doping and blood doping: the haematological module of the Athlete Biological Passport
Authors: Schumacher Yorck Olaf , Saugy Martial , Pottgiesser Torben , Robinson Neil 
Published: February 2012

The increase of the body's capacity to transport oxygen is a prime target for doping athletes in all endurance sports. For this pupose, blood transfusions or erythropoiesis stimulating agents (ESA), such as erythropoietin, NESP, and CERA are used. As direct detection of such manipulations is difficult, biomarkers that are connected to the haematopoietic system (haemoglobin concentration, reticulocytes) are monitored over time (Athlete Biological Passport (ABP)) and analyzed using mathematical models to identify patterns suspicious of doping. With this information, athletes can either be sanctioned directly based on their profile or targeted with conventional doping tests.Key issues for the appropriate use of the ABP are correct targeting and use of all available information (e.g. whereabouts, cross sectional population data) in a forensic manner.Future developments of the passport include the correction of all concentration‐based variables for shifts in plasma volume, which might considerably increase sensitivity. New passport markers from the genomic, proteomic, and metabolomic level might add further information, but need to be validated before integration into the passport procedure.A first assessment of blood data of federations that have implemented the passport show encouraging signs of a decreased blood‐doping prevalence in their athletes, which adds scientific credibility to this innovative concept in the fight against ESA‐ and blood doping. Copyright © 2012 John Wiley & Sons, Ltd.
Coordination Chemistry of α‐ω‐Bis(pyridylimine) Ligands Containing Flexible Linkers with Copper(I)
Authors: Hu Zhenzhong , Schneider Celine M. , Price Christina N. , Pye Whitney M. , Dawe Louise N. , Kerton Francesca M. 
Published: February 2012

AbstractCopper(I) complexes of a series of six potentially tetradentate bis(pyridylimine) ligands were prepared, where the pyridylimine groups were separated by different linking units [in L1, CH2CH2CH2(SiMe2O)20SiMe2CH2CH2CH2; in L2, CH2CH2CH2SiMe2OSiMe2CH2CH2CH2; in L3, CH2CH2; in L4, CH2(CH2)4CH2; in L5, CH2(CH2)7CH2; in L6, CH2CH2CH2OCH2CH2OCH2CH2OCH2CH2CH2]. The solubilities of L1, L2 and [Cu(L2)](PF6) in supercritical carbon dioxide were determined. The coordination chemistry of L1–L2 with CuI was studied by UV/Vis, multinuclear NMR and IR spectroscopy, MALDI‐TOF and ESI mass spectrometries and elemental analysis. These data suggested that [1+1] complexes had formed. Dicopper complexes of L3–L6 were prepared for comparison, and [Cu2(L5)2](PF6)2 characterized by single‐crystal X‐ray diffraction analysis. Close methylene C–H···π interactions are observed within the structure. PGSE NMR spectroscopy was used to determine the hydrodynamic radii of the species in solution and comparison of these data with computational models for the complexes was made. Freezing point depression measurements afforded molecular weights for solution‐state species in agreement with the formulations proposed via NMR and mass spectrometric data. There is no evidence to support linear metallopolymer formation but data suggest that [2+2] and [1+1] metallomacrocyles were formed, with siloxane linking groups encouraging the formation of [1+1] species. Solid‐state NMR spectroscopic data on [Cu(L1)](PF6) indicate the presence of two different environments for the PF6– anions.
A utility minimization approach for energy‐aware cooperative content distribution with fairness constraints
Authors: Yaacoub Elias , Al-Kanj Lina , Dawy Zaher , Sharafeddine Sanaa , Filali Fethi , Abu‐Dayya Adnan 
Published: February 2012

ABSTRACTCooperation between mobile terminals (MTs) with the objective of energy minimization is studied. The purpose is to distribute a content of common interest to collaborating MTs while ensuring a reduced energy consumption. To reach this goal, the content is sent to selected MTs on a long‐range link. Then, it is forwarded to other MTs on short‐range mobile‐to‐mobile links. The problem is formulated as an optimization problem, and the optimal solution is shown to consist of sending the content to a single MT on the long‐range link and of having that MT distribute it on the short‐range links. This leads to an unfair energy consumption for the selected MT. Thus, to ensure fairness in energy consumption, a low complexity utility minimization algorithm is proposed. Using the appropriate utilities, the algorithm can be used to implement the optimal greedy energy minimization solution or to ensure different degrees of fairness in energy consumption. Practical constraints concerning the centralised and distributed implementations of the proposed algorithm are also discussed. Simulation results show that significant energy savings can be achieved with the proposed approach compared with the non‐collaborative case. In addition, a tradeoff between fairness and energy savings is achieved depending on the utility selected. Copyright © 2012 John Wiley & Sons, Ltd.
An unfitted interior penalty discontinuous Galerkin method for incompressible Navier–Stokes two‐phase flow
Authors: Heimann F. , Engwer C. , Ippisch O. , Bastian P. 
Published: February 2012

SUMMARYA discontinuous Galerkin method for the solution of the immiscible and incompressible two‐phase flow problem based on the nonsymmetric interior penalty method is presented. Therefore, the incompressible Navier–Stokes equation is solved for a domain decomposed into two subdomains with different values of viscosity and density as well as a singular surface tension force. On the basis of a piecewise linear approximation of the interface, meshes for both phases are cut out of a structured mesh. The discontinuous finite elements are defined on the resulting Cartesian cut‐cell mesh and may therefore approximate the discontinuities of the pressure and the velocity derivatives across the interface with high accuracy. As the mesh resolves the interface, regularization of the density and viscosity jumps across the interface is not required. This preserves the local conservation property of the velocity field even in the vicinity of the interface and constitutes a significant advantage compared with standard methods that require regularization of these discontinuities and cannot represent the jumps and kinks in pressure and velocity. A powerful subtessellation algorithm is incorporated to allow the usage of standard time integrators (such as Crank–Nicholson) on the time‐dependent mesh. The presented discretization is applicable to both the two‐dimensional and three‐dimensional cases. The performance of our approach is demonstrated by application to a two‐dimensional benchmark problem, allowing for a thorough comparison with other numerical methods. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of mine dewatering on peatlands of the James Bay Lowland: the role of bioherms
Authors: Whittington Peter , Price Jonathan 
Published: February 2012

AbstractThe James Bay Lowland host one of the largest wetland complexes in the world in part due to the low permeability of marine sediments that suppress groundwater seepage losses. Dewatering of an open‐pit diamond mine in the area has depressurized the regional bedrock aquifer. Bioherms, fractured limestone outcroppings formed from ancient coral reefs that protrude to the peatland surface, lack this mantle of low‐permeability sediments and provide a direct connection between the peatland (surficial) and the regional (bedrock) aquifers. Well transects and piezometer nests were installed around seven bioherms in the depressurized zone and one in a non‐affected zone (control) to monitor the water table drawdown and change in hydraulic gradients around the bioherms. Water tables in the affected bioherms decreased between 2 and 4 m in the first 4 years of dewatering. The drawdown in the bioherms caused a localized water table drawdown in the peat surrounding the bioherms that extended to approximately 30 m from the edge of the bioherm during a dry period. Under wet conditions, drawdown was similar to that at the control site. Hydraulic gradients in the peat (which typically are very small) increased over the field seasons and in a few locations exceeded 1. These gradients represented significant losses to the local, near bioherm, system as at many of the locations surrounding the bioherms vertical seepage losses ranged between 1 and 4 mm/day, which are similar to the seasonal average evaporative water loss of ~ 3 mm/day. The bioherms are acting as efficient drainage nodes; however, their influence is localized to the peat immediately (~ <30 m) surrounding them. Copyright © 2012 John Wiley & Sons, Ltd.
Ultra‐small‐angle X‐ray scattering–X‐ray photon correlation spectroscopy studies of incipient structural changes in amorphous calcium phosphate‐based dental composites
Authors: Zhang Fan , Allen Andrew J. , Levine Lyle E. , Espinal Laura , Antonucci Joseph M. , Skrtic Drago , O'Donnell Justin N. R. , Ilavsky Jan 
Published: February 2012

AbstractThe local structural changes in amorphous calcium phosphate (ACP)‐based dental composites were studied under isothermal conditions using both static, bulk measurement techniques and a recently developed methodology based on combined ultra‐small angle X‐ray scattering–X‐ray photon correlation spectroscopy (USAXS–XPCS), which permits a dynamic approach. While results from conventional bulk measurements do not show clear signs of structural change, USAXS–XPCS results reveal unambiguous evidence for local structural variations on a similar time scale to that of water loss in the ACP fillers. A thermal‐expansion‐based simulation indicates that thermal behavior alone does not account for the observed dynamics. Together, these results suggest that changes in the water content of ACP affect the composite morphology due to changes in ACP structure that occur without an amorphous‐to‐crystalline conversion. It is also noted that biomedical materials research could benefit greatly from USAXS–XPCS, a dynamic approach. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2012.
Bone mineral as an electrical energy reservoir
Authors: Nakamura Miho , Hiratai Rumi , Yamashita Kimihiro 
Published: February 2012

AbstractMechanical stress in bone induces an electrical potential generated by piezoelectricity arising from displacement of collagen fibrils. Where and for how long the potential is stored in bone; however, are still poorly understood. We investigated the electrical properties of collagen fibrils and apatite minerals and found that bone, when polarized electrically by applying an external voltage, depolarizes by two mechanisms. Plots of thermally stimulated depolarization current show two significant peaks: one at 100°C, attributed to collagen fibrils because decalcified bone exhibits depolarization peak at 100°C, and the other at 500°C, attributed to apatite minerals because calcined bone exhibits depolarization peak at 500°C and has activation energy similar to that for synthesized apatite. The crystallographic c‐axis orientation of calcined bone depends on the direction in which the bone is cut, either transverse or longitudinal, and strongly affects the polarization efficacy. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2012.
Zwitterionic polycarboxybetaine coating functionalized with REDV peptide to improve selectivity for endothelial cells
Authors: Ji Ying , Wei Yu , Liu Xiangsheng , Wang Jinlei , Ren Kefeng , Ji Jian 
Published: February 2012

AbstractSurface immobilization of bioactive molecules has been a promising strategy to develop in situ endothelialization for cardiovascular implants. With the aim to construct endothelial cell specific coating with low fouling property, zwitterionic carboxybetaine methacrylate and butyl methacrylate were copolymerized as coating materials, spin‐coated onto substrates, and immobilized with endothelial cell selective peptide Arg‐Glu‐Asp‐Val (REDV) through functionalization of carboxy groups in carboxybetaine by NHS/EDC chemistry. Experimental results proved that carboxybetaine‐REDV coating maintained desirable antifouling ability and fine hemocompatibility. Separate culture and coculture of HUVECs (human umbilical vein endothelial cells) with HUASMCs (human umbilical artery smooth muscle cells) showed that the coating was able to enhance the competitive growth of endothelial cells while limiting the adhesion, proliferation, and migration of smooth muscle cells. The existence of zwitterionic carboxybetaine helps to screen undesirable adsorption of platelets, and its nonspecific resistance to smooth muscle cells contributes to the realization of endothelial cell selectivity. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2012.
A TDDFT investigation of bay substituted perylenediimides: Absorption and intersystem crossing
Authors: Quartarolo Angelo Domenico , Chiodo Sandro Giuseppe , Russo Nino 
Published: February 2012

AbstractThe conformational structure and electronic spectra properties of a series of bay substituted perylenediimides (PDI) derivatives have been investigated by means of density functional theory (DFT) and time‐dependent DFT. The B3LYP and PBE0 hybrid exchange‐correlation functionals were applied in conjunction with the double‐ζ quality SVP basis set. These compounds are interesting for organic materials science and as photosensitizers in cancer phototherapy (PDT), because of their intense absorption in the visible region. Results show that the substitution at the bay position of the PDI parent molecule with N‐alkyl groups shifts the absorption maxima towards the red part of the visible spectrum (around 650–700 nm) as required for the applications in PDT. The main PDT action mechanisms have been investigated by computing of electron affinities, ionization potentials, triplet energies and spin‐orbit matrix elements between singlet and triplet excited states. © 2012 Wiley Periodicals, Inc.