bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vegetation impacts on near bank flow
Authors: Hopkinson Leslie , Wynn Theresa 
Published: October 2009

AbstractVegetation is an important component of stream restoration designs used to control streambank retreat, but vegetation effects on near bank flows need to be quantified. The goal of this research was to evaluate how three‐dimensional velocity structure and turbulence characteristics vary with three vegetation treatments: tree, shrub and grass. A second order prototype stream (Tom's Creek in Blacksburg, Virginia, USA) with individual reaches dominated by each vegetation treatment was modelled in a research flume using a fixed‐bed Froude‐scale modelling technique. One model streambank of the prototype stream was constructed for each vegetation type and compared to a bare control (only grain roughness). Velocity profiles perpendicular to the flume model boundary were measured using a three‐dimensional acoustic Doppler velocimeter. Three‐dimensional velocity records, turbulent kinetic energy characteristics, and Reynolds stresses were analysed. The addition of vegetation on a sloping streambank increased the free stream streamwise velocity as compared to a bare streambank. Velocity in the downstream direction decreased in the area close to the streambank boundary for all vegetation treatments. Tree turbulence intensity and Reynolds stress distributions were similar to the bare condition due to the sparse tree placement characteristic of mature forests. The turbulence caused by the upright shrub treatment increased turbulent kinetic energy and Reynolds stresses near the streambank, particularly at the toe. The flexible grass vegetation folded and protected the streambank, reducing shear stress near the boundary. Copyright © 2009 John Wiley & Sons, Ltd.
Molecular Interaction between a Gadolinium–Polyoxometalate and Human Serum Albumin
Authors: Zheng Li , Ma Ying , Zhang Guangjin , Yao Jiannian , Bassil Bassem S. , Kortz Ulrich , Keita Bineta , de Oliveira Pedro , Nadjo Louis , Craescu Constantin T. , Miron Simona 
Published: October 2009

AbstractPolyoxometalates (POMs) show promising antibacterial, antiviral (particularly anti‐HIV), antitumor, and anticancer activities, but the mechanism of these potential therapeutic effects remains to be elucidated at the molecular level. The interaction between the Gd‐containing tungstosilicate [Gd(β2‐SiW11O39)2]13– and human serum albumin (HSA) was studied by several techniques. Fluorescence spectroscopy showed an energy transfer between the single tryptophan residue of HSA and the POM. Circular dichroism led to the conclusion that the POM significantly altered the secondary structure of HSA. Isothermal titration calorimetry revealed an enthalpy‐driven binding reaction between HSA and the POM, resulting in the formation of a 1:1 complex.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Conversion of Carbon–Fluorine Bonds α to Transition Metal Centers to Carbon–Hydrogen, Carbon–Carbon, and Carbon–Heteroatom Bonds
Authors: Hughes Russell P. 
Published: October 2009

AbstractPseudo‐tetrahedral primary fluoroalkyl complexes of iridium provide a template on which to study the stereoselectivity of carbon–fluorine bond activation α to iridium by external protic acids. Coupled with migration of internal nucleophiles, this reaction leads to diastereoselective formation of new carbon–oxygen, carbon–sulfur, carbon–hydrogen, and carbon–carbon bonds. Stereochemical studies of the conformational properties of starting fluoroalkyl complexes and relativestereocenter configurations for diastereomeric products, together with kinetic studies of reactions in different solvents, allow a self‐consistent mechanism for these reactions to be established. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of New Chiral Ketones from D‐Glucose Derivatives and Their Use in the Enantioselective Epoxidation of Arylalkenes
Authors: Vega‐Pérez José Manuel , Vega Holm Margarita , Martínez M. Luisa , Blanco Eugenia , Iglesias‐Guerra Fernando 
Published: October 2009

AbstractA new backbone model for a chiral carbohydrate‐derived ketone for asymmetric epoxidation is presented. The oxo function is sited in a seven‐membered ring fused to the sugar moety. The synthesized compound is an effective chirality‐transfer agent in dioxirane‐mediated epoxidation, giving ees of up to 74 %. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Iso‐seco‐tanapartholides: Isolation, Synthesis and Biological Evaluation
Authors: Makiyi Edward F. , Frade Raquel F. M. , Lebl Tomas , Jaffray Ellis G. , Cobb Susan E. , Harvey Alan L. , Slawin Alexandra M. Z. , Hay Ronald T. , Westwood Nicholas J. 
Published: October 2009

AbstractThe isolation, identification and total synthesis of two plant‐derived inhibitors of the NF‐κB signaling pathway from the iso‐seco‐tanapartholide family of natural products is described. A key step in the efficient reaction sequence is a late‐stage oxidative cleavage reaction that was carried out in the absence of protecting groups to give the natural products directly. A detailed comparison of the synthetic material with samples of the natural products proved informative. Biological studies on synthetic material confirmed that these compounds act late in the NF‐κB signaling pathway. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Structural analysis of glycosphingolipid analogues obtained by the saccharide primer method using CE‐ESI‐MS
Authors: Zhu Xingyu , Hatanaka Kenichi , Yamagata Tatsuya , Sato Toshinori 
Published: October 2009

AbstractA glycosphingolipid analogue (12‐azidododecyl β‐lactoside) as a saccharide primer has been shown to be useful for the synthesis of oligosaccharide libraries by mammalian cells. In the present study, CE‐ESI‐MS was employed to elucidate the structure of glycosphingolipid analogues derived from 12‐azidododecyl β‐lactoside (Lac‐C12N3) by mammalian cells. MDCK cells and COLO201 cells were cultured with Lac‐C12N3, and the glycosylated products secreted into the medium were collected and separated into acidic and neutral products by column chromatography. The acidic products could be directly analyzed by CE‐ESI‐MS, while the neutral products were converted to anionic derivatives via a reaction with propiolic acid. With this method, it was possible to analyze both acidic and neutral products glycosylated by MDCK cells and COLO201 cells at high sensitivity.
Evaluation of fault relative location algorithms using voltage sag data collected at 25‐kV substations
Authors: Núñez Victor Barrera , Frigola Joaquim Melendez , Jaramillo Sergio Herraiz , Losada Jorge Sánchez 
Published: October 2009

AbstractSource location algorithms, recently proposed in the literature as a means to determine the origin of sags upstream or downstream from the measuring point, have been compared. Testing has been carried out using 471 records of asymmetrical voltage sags gathered from HV/MV substations of the Catalan power network, in the northeast of Spain. Six different algorithms have been included in the test, and the significance of their attributes has been analysed using a data mining approach. Multivariate statistical theory (MANOVA) has been used in this analysis. The work has been completed by improving the performance of the algorithms applying a machine learning induction algorithm (CN2), designed to extract new classification rules dealing with the combination of the attributes defined by the algorithms analysed. The study considers phase‐to‐ground and phase‐to‐phase faults separately. Copyright © 2009 John Wiley & Sons, Ltd.
A comparison between a collocation and weak implementation of the rigid‐body motion constraint on a particle surface
Authors: D'Avino G. , Hulsen M. A. 
Published: October 2009

AbstractIn this work, we implemented and compared two different methods to impose the rigid‐body motion constraint on a solid particle moving inside a fluid. We consider a fictitious domain method to easily manage the particle motion. As the solid as well as the fluid inertia are neglected, the particle can be discretized through its boundary only. The rigid‐body motion is imposed via Lagrange multipliers on the boundary. In the first method, such constraints are imposed in discrete points on the boundary (collocation), whereas in the second the constraint is imposed in a weak way on elements dividing the particle surface.Two test problems, that is, a spherical and an ellipsoidal particle in a sheared Newtonian fluid, are chosen to compare the methods. In both cases, the analysis is carried out in 2D as well as in 3D.The results show that for the collocation method an optimal number of collocation points exist leading to the smallest error. However, small variations in the optimal value can generate large deviations. In the weak implementation, the error is only mildly affected by the number of elements used to discretize the particle boundary and by the Lagrange multiplier's interpolation space. A further analysis is carried out to study the effect of an approximated integration of weak constraints.A comparison between the two methods showed that the same accuracy can be achieved by using less constraints if the weak discretization is used. Finally, the rigid‐body motion imposed via weak constraints leads to better conditioned linear systems. Copyright © 2009 John Wiley & Sons, Ltd.
An explicit level set approach for generalized shape optimization of fluids with the lattice Boltzmann method
Authors: Kreissl Sebastian , Pingen Georg , Maute Kurt 
Published: October 2009

AbstractThis study is concerned with a generalized shape optimization approach for finding the geometry of fluidic devices and obstacles immersed in flows. Our approach is based on a level set representation of the fluid–solid interface and a hydrodynamic lattice Boltzmann method to predict the flow field. We present an explicit level set method that does not involve the solution of the Hamilton–Jacobi equation and allows using standard nonlinear programming methods. In contrast to previous works, the boundary conditions along the fluid–structure interface are enforced by second‐order accurate interpolation schemes, overcoming shortcomings of flow penalization methods and Brinkman formulations frequently used in topology optimization. To ensure smooth boundaries and mesh‐independent results, we introduce a simple, computationally inexpensive filtering method to regularize the level set field. Furthermore, we define box constraints for the design variables that guarantee a continuous evolution of the boundaries. The features of the proposed method are studied by two numeric examples of two‐dimensional steady‐state flow problems. Copyright © 2009 John Wiley & Sons, Ltd.
Technical Analysis of an Eco‐Friendly Hybrid Plant With a Microgas Turbine and an MCFC System
Authors: De Lorenzo G. , Fragiacomo P. 
Published: October 2009

AbstractThis article refers to a Molten Carbonate Fuel Cell (MCFC) system coupled to a plant with a microgas turbine and a heat recovery system for obtaining a small sized hybrid system in co‐generative arrangement.MCFC are devices capable of concentrating carbon dioxide (CO2) produced in anode exhaust gases. If they are handled conveniently, it is possible to separate and store the surplus CO2 produced by the plant instead of emitting it into the atmosphere.From the simulation model of the MCFC system, previously developed by the authors, a zero‐dimensional and stationary simulation model for the whole hybrid system was formulated and implemented in the same language.By the simulation model of the MCFC system it has been possible to make a parametric analysis of the hybrid plant to find some optimal operating conditions of the fuel cell(s) that maximise the performance of the entire hybrid plant. In addition, the separation of the CO2 surplus produced by the hybrid plant was simulated by the model and then the emissions of carbon monoxide (CO) and nitrogen oxides (NOx) from the same plant were evaluated.
The Rheology of Stabilised Lanthanum Strontium Cobaltite Ferrite Nanopowders in Organic Medium Applicable as Screen Printed SOFC Cathode Layers
Authors: Burnat D. , Ried P. , Holtappels P. , Heel A. , Graule T. , Kata D. 
Published: October 2009

AbstractThe production and optimisation of screen printing (SP) pastes containing La0.58Sr0.42Co0.21Fe0.79O3 – δ and La0.61Sr0.41Co0.19Fe0.79O3 – δ (LSCF) were investigated. The application of these nanopowders is supposed to improve the cathode's microstructure and increase its mechanical strength. Thirty seven pastes containing LSCF were carried out with variation in binders, dispersants and different particle size distribution. The rheological behaviour of these pastes was investigated. It was found that commercially available dispersant Solsperse 3000 resulted in the best suspension stability, achieving almost 55 times lower viscosity value for pastes containing 20 vol.‐%, than pastes without any dispersants. The shear thinning behaviour was found to be favourable for the LSCF cathode deposition. A cathode made from the mixture of nano and submicron powder exhibits a polarisation resistance as low as 0.76 Ω cm2 at 592 °C.
A Direct Electron Transfer‐Based Glucose/Oxygen Biofuel Cell Operating in Human Serum
Authors: Coman V. , Ludwig R. , Harreither W. , Haltrich D. , Gorton L. , Ruzgas T. , Shleev S. 
Published: October 2009

AbstractWe report on the fabrication and characterisation of the very first direct electron transfer‐based glucose/oxygen biofuel cell (BFC) operating in neutral glucose‐containing buffer and human serum. Corynascus thermophilus cellobiose dehydrogenase and Myrothecium verrucaria bilirubin oxidase were used as anodic and cathodic bioelements, respectively. The following characteristics of the mediator‐, separator‐ and membrane‐less, a priori, non‐toxic and simple miniature BFC, was obtained: an open‐circuit voltage of 0.62 and 0.58 V, a maximum power density of ca. 3 and 4 μW cm–2 at 0.37 and 0.19 V of cell voltage, in phosphate buffer and human serum, respectively.
Morphological Radiation with Reference to the Carapace Valves of the Anomopoda (Crustacea: Cladocera)
Authors: Smirnov Nikolai N. , Kotov Alexey A. 
Published: October 2009

AbstractDiversity of the carapace valve structure in the Anomopoda (Crustacea: Branchiopoda) is described. We found that transformations of shape, modifications of the surface and valve margins, and thickening or thinning of the valves, take place independently in different families, sometimes resulting in a convergent similarity. The limits of morphological diversity in these features determine the range of adaptive radiation in general form of the group. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
False Correlates of Nested Patterns: A Case Study Using Temporary Pond Microcrustaceans
Authors: Fernández Ana I. , Viedma Olga , Angeler David G. 
Published: October 2009

AbstractNestedness analysis is a popular tool for inferring spatial species distributions, and therefore has management and conservation relevance. Ecologists frequently compute nestedness and subsequently use Spearman rank correlations for inferring relationships between the observed nested ranks of sites with biogeographic and environmental variables. Using temporary pond microcrustaceans hatched from microcosms as a case study, this paper shows that the application of this method can be problematic. While the overall degree and significance of nestedness was robust against a statistical error, the results obtained from randomly generated matrices, in which community structure from the original microcrustacean incidence matrix was maintained (fixed rows –fixed columns constraints), showed that rank correlations of observed nested patterns can be vulnerable to a Type 1 error (detecting an effect when there is none). Using expected nestedness patterns derived from rarefied original matrices to control for sample size effects did not change this result. This problem may have arisen as a result of a quantitative bias related to the disproportionate impact of rank positions of individual ponds in the analysis. Future extensive simulations studies, involving different community structures, should help identify the general reliability of rank correlation results in nestedness analyses. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
PCR‐DGGE Fingerprinting Analysis of Plankton Communities and Its Relationship to Lake Trophic Status
Authors: Wu Li , Yu Yuhe , Zhang Tanglin , Feng Weisong , Zhang Xiang , Li Wei 
Published: October 2009

AbstractPlankton communities in eight lakes of different trophic status near Yangtze, China were charac‐terized by using denatured gradient gel electrophoresis (DGGE). Various water quality parameters were also measured at each collection site. Following extraction of DNA from plankton communi‐ties, 16S rRNA and 18S rRNA genes were amplified with specific primers for prokaryotes and eu‐karyotes, respectively; DNA profiles were developed by DGGE. The plankton community of each lake had its own distinct DNA profile. The total number of bands identified at 34 sampling stations ranged from 37 to 111. Both prokaryotes and eukaryotes displayed complex fingerprints composed of a large number of bands: 16 to 59 bands were obtained with the prokaryotic primer set; 21 to 52 bands for the eukaryotic primer set. The DGGE‐patterns were analyzed in relation to water quality parameters by canonical correspondence analysis (CCA). Temperature, pH, alkalinity, and the con‐centration of COD, TP and TN were strongly correlated with the DGGE patterns. The parameters that demonstrated a strong correlation to the DGGE fingerprints of the plankton community differed among lakes, suggesting that differences in the DGGE fingerprints were due mainly to lake trophic status. Results of the present study suggest that PCR‐DGGE fingerprinting is an effective and precise method of identifying changes to plankton community composition, and therefore could be a useful ecological tool for monitoring the response of aquatic ecosystems to environmental perturbations. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carbon‐14 labeled methyl 2‐chloro‐2‐oxoacetate: a convenient carbon‐14 labeled oxalyl chloride equivalent
Authors: Burrell Richard C. , Easter John A. , Bonacorsi Samuel J. , Balasubramanian Balu 
Published: October 2009

AbstractOxalyl chloride is a versatile two‐carbon building block for synthesizing organic molecules. Carbon‐14 labeled oxalyl chloride should be a useful reagent for labeling many of these compounds. Unfortunately, its preparation suffers from low radiochemical yield and problems with stability, isolation and analysis. Because of these issues, the reagent is not a convenient or practical carbon‐14 label source. Synthetically, methyl 2‐chloro‐2‐oxoacetate reacts as an oxalyl chloride equivalent. This report describes a reliable and efficient two‐step synthesis of carbon‐14 labeled methyl 2‐chloro‐2‐oxoacetate ([14C]‐1) from readily available carbon‐14 labeled dimethyl oxalate ([14C]‐2). The labeled oxalate was first treated with aqueous base to give the mono‐potassium salt of 2‐methoxy‐2‐oxoacetate ([14C]‐3), which was then reacted with oxalyl chloride to give [14C]‐1 as a solution in dichloromethane. The overall radiochemical yield for this process was essentially quantitative, and [14C]‐1 was found to be stable and easy to use in further synthetic manipulations. Copyright © 2009 John Wiley & Sons, Ltd.
Site‐specific addition of an 18F‐N‐methylaminooxy‐containing prosthetic group to a vinylsulfone modified peptide
Authors: Olberg Dag Erlend , Hjelstuen Ole Kristian , Solbakken Magne , Arukwe Joseph M. , Dyrstad Knut , Cuthbertson Alan 
Published: October 2009

AbstractNumerous strategies employing prosthetic groups for the radiosynthesis of 18F‐fluorinated peptides for positron emission tomography have been investigated in recent years. We have previously reported a novel [18F]prosthetic group bearing the N‐methylaminooxy functionality capable of reacting in a site‐selective manner with peptides functionalized with Michael‐acceptors. In a further extension of this methodology we demonstrate that O‐[2‐(2‐[18F]fluoroethoxy)ethyl]‐N‐methyl‐N‐hydroxylamine, [18F]4, reacts chemoselectively with a vinylsulfone functionalized peptide. The conjugation yields were studied with respect to reaction time, level of radioactivity, peptide concentration and purity of the [18F]prosthetic group used in the conjugation reaction. Incubation at 70°C gave conjugation yields of around 80% with high radiochemical purity after 70 min at pH 5 in acetate buffer. Copyright © 2009 John Wiley & Sons, Ltd.
Laser Raman spectroscopic investigations of biodegradable vehicle of active agents eluting LVM 316 stainless steel cardiovascular stents for in vivo degradation characteristics
Authors: Sudheer S. K. , Prathibha S. , Kothwala D. , Engineer C. , Raval A. , Jerriwala A. B. , Kotadia H. 
Published: October 2009

AbstractLaser Raman spectroscopy is an effective tool for the study of biodegradable polymers, which play a vital role in the new developments in coronary implants such as stents. There is much excitement around the potential capabilities of synthetic biodegradable polymers and the effect they will have on the design and function of implanted devices. In the present investigation, heparin‐conjugated biodegradable copolymers were evaluated for their durability as drug‐eluting stent coatings. Laser Raman spectroscopic studies were carried out and spectra recorded and analyzed of explanted stents coated with different amounts of polymer alone, showing the existence of different levels at different quantities of polymer. The polymer was detected on every stent analyzed. On the stents coated with a thick layer of polymer, a firm layer of polymer still existed on the stent. In contrast, this layer was degraded and spread around on the stents coated with only a thin layer of the polymer. This indicates that the polymers used in the stents in the present investigation exhibit acceptable biodegradability. Such polymers can be used as efficient drug carriers, as these materials show good degradation after the stipulated period. Copyright © 2009 John Wiley & Sons, Ltd.
Surface‐enhanced Raman scattering of silylated graphite oxide sheets sandwiched between colloidal silver nanoparticles and silver piece
Authors: Fu Xiaoqi , Bei Fengli , Wang Xin , Yang Xujie , Lu Lude 
Published: October 2009

AbstractGraphite oxide (GO) was successfully silylated by 3‐mercaptopropyltrimethoxysilane. The surface‐enhanced Raman scattering spectrum of the silylated GO sheets sandwiched between colloidal silver nanoparticles and silver piece is presented. The Raman signal shows a 104 enhancement compared to that of bulk GO. The large Raman enhancement is most likely a result of electromagnetic (EM) coupling between the colloidal silver nanoparticles (localized surface plasmon) and the silver piece (surface plasmon polariton), creating large localized EM fields at their interface, where the silylated GO sheets reside in this sandwich architecture. Copyright © 2009 John Wiley & Sons, Ltd.