bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measuring local RF heating in MRI: Simulating perfusion in a perfusionless phantom
Authors: Akca Imran B. , Ferhanoglu Onur , Yeung Christopher J. , Guney Sevin , Tasci T. Onur , Atalar Ergin 
Published: October 2007

AbstractPurposeTo overcome conflicting methods of local RF heating measurements by proposing a simple technique for predicting in vivo temperature rise by using a gel phantom experiment.Materials and MethodsIn vivo temperature measurements are difficult to conduct reproducibly; fluid phantoms introduce convection, and gel phantom lacks perfusion. In the proposed method the local temperature rise is measured in a gel phantom at a timepoint that the phantom temperature would be equal to the perfused body steady‐state temperature value. The idea comes from the fact that the steady‐state temperature rise in a perfused body is smaller than the steady‐state temperature increase in a perfusionless phantom. Therefore, when measuring the temperature on a phantom there will be the timepoint that corresponds to the perfusion time constant of the body part.ResultsThe proposed method was tested with several phantom and in vivo experiments. Instead, an overall average of 30.8% error can be given as the amount of underestimation with the proposed method. This error is within the variability of in vivo experiments (45%).ConclusionWith the aid of this reliable temperature rise prediction the amount of power delivered by the scanner can be controlled, enabling safe MRI examinations of patients with implants. J. Magn. Reson. Imaging 2007;26:1228–1235. © 2007 Wiley‐Liss, Inc.
Full‐wave‐based transmission‐line model for lossy‐substrate multiconductor interconnects
Authors: Kordi Behzad , Bridges Greg E. , LoVetri Joe , Nordstrom John E. 
Published: October 2007

AbstractA full‐wave‐based modal analysis is used for simulating a multiconductor coplanar waveguide (CPW) over a selectively etched lossy silicon substrate. Propagating modes, which are similar to the classic ‘common’ and ‘differential’ modes, are extracted, and circuit theory energy relationships are used for the determination of transmission‐line model parameters. A time‐frequency domain technique is employed for implementing the transmission‐line model within a circuit simulator. The model is used to study the effect of etching the dielectric and the substrate for a two‐conductor CPW line. The simulation results show that etching both the dielectric and the lossy substrate improves the loss and dispersion characteristics of the CPW line. Copyright © 2007 John Wiley & Sons, Ltd.
Cx29 and Cx32, two connexins expressed by myelinating glia, do not interact and are functionally distinct
Authors: Ahn Meejin , Lee Jonathan , Gustafsson Andreas , Enriquez Alan , Lancaster Eric , Sul Jai‐Yoon , Haydon Philip G. , Paul David L. , Huang Yan , Abrams Charles K. , Scherer Steven S. 
Published: October 2007

AbstractIn rodents, oligodendrocytes and myelinating Schwann cells express connexin32 (Cx32) and Cx29, which have different localizations in the two cell types. We show here that, in contrast to Cx32, Cx29 does not form gap junction plaques or functional gap junctions in transfected cells. Furthermore, when expressed together, Cx29 and Cx32 are not colocalized and do not coimmunoprecipitate. To determine the structural basis of their divergent behavior, we generated a series of chimeric Cx32‐Cx29 proteins by exchanging their intracellular loops and/or their C‐terminal cytoplasmic tails. Although some chimerae reach the cell membrane, others appear to be largely localized intracellularly; none form gap junction plaques or functional gap junctions. Substituting the C‐terminus or the intracellular loop and the C‐terminus of Cx32 with those of Cx29 does not disrupt their colocalization or coimmunoprecipitation with Cx32. Substituting the C‐terminus of Cx29 with that of Cx32 does not disrupt the coimmunoprecipitation or the colocalization with Cx29, whereas substituting both the intracellular loop and the C‐terminus of Cx32 with those of Cx29 diminishes the coimmunoprecipitation with Cx29. Conversely, the Cx32 chimera that contains the intracellular loop of Cx29 coimmunoprecipitates with Cx29, indicating that the intracellular loop participates in Cx29‐Cx29 interactions. These data indicate that homomeric interactions of Cx29 and especially Cx32 largely require other domains: the N‐terminus, transmembrane domains, and extracellular loops. Substituting the intracellular loop and/or tail of Cx32 with those of Cx29 appears to prevent Cx32 from forming functional gap junctions. © 2007 Wiley‐Liss, Inc.
Virtual 3D planning of acetabular fracture reduction
Authors: Citak Musa , Gardner Michael J. , Kendoff Daniel , Tarte Ségolène , Krettek Christian , Nolte Lutz‐Peter , Hüfner Tobias 
Published: October 2007

AbstractDisplaced acetabular fractures are best treated with open reduction to achieve anatomic reduction and maximize the chance of a good functional outcome. Because of the anatomic complexity and often limited visualization, fracture reduction can be difficult. Virtual planning software can allow the surgeon to understand the fracture morphology and to rehearse reduction maneuvers. The purpose of this study was to determine the effect of a novel virtual fracture reduction module on time and accuracy of reduction. Four acetabular fracture patterns were created in synthetic pelves, which were implanted with fiducial markers and were registered with CT scan. Ten surgeons used virtual fracture reduction software or conventional 2D planning methods and immediately reduced the fractures blindly in a viscous gel medium. 3D imaging was again performed and the accuracy of reduction was assessed. The average malreduction was significantly improved following planning with the virtual software compared to the standard technique. The time taken for reduction was also significantly less for two of the four fracture patterns. Virtual software may be useful for visualizing and planning treatment of fractures of the acetabulum, potentially leading to more accurate and efficient reductions, and may also be an effective educational tool. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:547–552, 2008
Effect of altered mechanical load conditions on the structure and function of cultured tendon fascicles
Authors: Abreu Eduardo L. , Leigh Diane , Derwin Kathleen A. 
Published: October 2007

AbstractWe have developed an in vitro model system to investigate the relationships between mechanical unloading and tendon matrix remodeling. Remodeling was characterized by changes in the functional and structural characteristics of rat tail tendon fascicles (RTTF) subjected to no load conditions for 1 week in vitro. We hypothesized that the absence of load will: (I) maintain cross‐sectional area (CSA), with decreased elastic modulus and increased stress‐relaxation; (II) cause an increase in denatured collagen and a decrease in water and total glycosaminoglycan (GAG) content. Fascicles cultured under a nominal static stress were used as control for culture conditions effects. Unloading resulted in a decrease of approximately 23% in the elastic modulus of cultured fascicles, consistent with previous stress‐deprivation studies. Contrary to our hypothesis, a nominal static stress caused an increase in elastic modulus (∼30%) and a significant decrease in stress‐relaxation when compared to fresh fascicles at 1% strain. Mechanical changes were associated with changes in the GAG content of the fascicles, but not their CSA, water, or collagen content. Furthermore, we did not find evidence of measurable denatured collagen in the cultured fascicles. Together these results suggest a role for GAG but not collagen or water in the elastic and viscoelastic changes measured in tendon fascicles cultured for 1 week under altered load conditions. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:364–373, 2008
The changing orientation of marketing: an emerging post‐modern perspective
Authors: Dekel Ofer , Prince Christopher , Beaver Graham 
Published: October 2007

Abstract
This paper argues that British society, together with the other parts of the post‐industrial world, is undergoing extraordinary change. Moreover, this change seems to be affecting all people and institutions. This paper argues that this transformation presents a number of challenges to current marketing orthodoxy and explores how marketing might need to evolve to operate in the emerging mass customization, post‐modern, post‐industrial environment.
The paper presents the argument that the new role of marketing in this post‐modern world will be to help individuals in consumer culture to increase their ability to choose identities and negotiate their position in society by the creative use of their lifestyles and consumption. While presenting real challenges, the new marketing landscape offers real business opportunities to those who are willing to engage with this new emerging reality.
Copyright © 2007 John Wiley & Sons, Ltd.
The evolution of business knowledge in SMEs: conceptualizing strategic space
Authors: Jones Oswald , Macpherson Allan , Thorpe Richard , Ghecham Adnan 
Published: October 2007

AbstractThis paper develops a conceptualization of the way in which owner‐managers in SMEs create strategic space. The term is defined as the time, resources, motivation and capabilities needed for owner‐managers to reflect on and review existing practices leading to learning, transformation and higher organizational performance.The empirical data is based on a longitudinal study of 90 SMEs operating in six broad sectors. The analysis uses two statistical tests to examine links between 20 activities within these SMEs and their performance.The results identify strong links between two groups of factors and positive performance claims by owner‐managers. Social attributes include work atmosphere, meetings and socializing. Structural attributes include training, knowledge structure, certification, systems and procedures.Copyright © 2007 John Wiley & Sons, Ltd.
Online preconcentration using monoliths in electrochromatography capillary format and microchips
Authors: Augustin Violaine , Proczek Gaëlle , Dugay José , Descroix Stéphanie , Hennion Marie‐Claire 
Published: October 2007

AbstractOnline preconcentration and separation of analytes using an in situ photopolymerized hexyl acrylate‐based monolith stationary phase was evaluated using electrochromatography in capillary format and microchip. The band broadening occurring during the preconcentration process by frontal electrochromatography and during the desorption process by elution electrochromatography was studied. The hexyl acrylate‐based monolith provides high retention for neutral analytes allowing the handling of large sample volumes and its structure allows rapid mass transfer, thus reducing the band broadening. For moderately polar analytes such as mono‐chlorophenols that are slightly retained in water, it was shown that enrichment factors up to 3500 can be obtained by a hydrodynamic injection of several bed volumes for 120 min under 0.8 MPa with a decrease in efficiency of 50% and a decrease of 30% for the resolution between 2‐ and 3‐chlorophenol. An 8 min preconcentration time allows enrichment factors above 100 for polyaromatic hydrocarbons. The interest of these monoliths when synthesized in microchip is also demonstrated. A 200‐fold enrichment was easily obtained for PAHs with only 1 min as preconcentration time, without decrease in efficiency.
Kinetic modeling of aqueous phenol degradation by UV/H2O2 process
Authors: Edalatmanesh Maryam , Dhib Ramdhane , Mehrvar Mehrab 
Published: October 2007

AbstractA dynamic kinetic model for the oxidation of phenol in water by an UV/H2O2 process is developed. The model is based on the elementary chemical and photochemical reactions, initiated by the photolysis of hydrogen peroxide into hydroxyl radicals. The model is validated by using experimental data obtained from the open literature for an actual UV/H2O2 process. Using those data and the developed kinetic model, kinetic rate constants for phenol intermediates, catechol and hydroquinone, are estimated. Moreover, the optimum initial hydrogen peroxide concentration is estimated by means of the validated model. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 40: 34–43, 2008
Photoresponsive New Polysiloxanes with 4‐Substituted Azobenzene Side‐Groups. Synthesis, Characterization and Kinetics of the Reversible Trans‐Cis‐Trans Isomerization
Authors: Hurduc Nicolae , Adès Dominique , Belleney Joël , Siove Alain , Sauvet Georges 
Published: October 2007

AbstractNew polydimethylsiloxanes with p‐substituted azobenzene side‐groups were synthesized. Thin films and solutions exhibit a photochemical trans‐cis isomerization of the azobenzene groups, followed by their cis‐trans thermal relaxation in the dark. In films, relaxation rates were found to be 100–1 000 times slower than the rates of photoisomerization, the former being very sensitive to the electron‐acceptor character of the substituents. in solution, the rates of cis‐trans relaxation are lower than those obtained for the solid state. This is ascribed to the dipolar intramolecular interactions between cis chromophores, which are favored in solution.magnified image
Molecularly Imprinted Polymers for Cholecystokinin C‐Terminal Pentapeptide Recognition
Authors: Papaioannou Emmanuel H. , Liakopoulou‐Kyriakides Maria , Papi Rigini M. , Kyriakidis Dimitrios A. 
Published: October 2007

AbstractMolecularly imprinted polymers (MIPs) have been prepared from methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) as the functional monomer and crosslinker, respectively, for cholecystokinin C terminal pentapeptide (CCK‐5), and screened for their rebinding characteristics. They were produced with alterations in the molar ratio of template/monomer/crosslinker and the percentage of net rebinding and the imprinting factor (IF) were used for the evaluation of their imprinting efficacy. The dissociation constant values determined in the case of the polymers with better characteristics, further confirmed the results above. Scanning electron microscopy (SEM) images of MIPs were also obtained in an attempt to correlate their characteristics with polymer's morphology. Rebinding experiments with CCK‐5 and CCK‐8 peptides in the case of the polymer that presented higher performance, with net rebinding values 11.9 and 9%, respectively, indicated that this polymer may be a good candidate for the analysis of CCK‐related peptides.magnified image
Silver Nanoparticles Stabilized by Thermoresponsive Microgel Particles: Synthesis and Evidence of an Electron Donor‐Acceptor Effect
Authors: Dong Yang , Ma Ying , Zhai Tianyou , Shen Fugang , Zeng Yi , Fu Hongbing , Yao Jiannian 
Published: October 2007

AbstractWell‐dispersed silver nanoparticles were successfully fabricated within poly[(N‐isopropylacrylamide)‐co‐(acrylic acid)] [P(NIPAM‐co‐AA)] microgel particles which were synthesized with different cross‐linking densities. Their structures were studied by field‐emission scanning electron microscopy, transmission electron microscopy, UV‐vis spectroscopy, X‐ray diffraction and FT‐IR spectroscopy. The interactions between the microgel particles and the incorporated silver nanoparticles were investigated by X‐ray photoelectron spectroscopy. The results revealed that there was charge transfer from the carbonyl groups of the microgel particles to the silver nanoparticles. Moreover, as the diameter of the AgNPs decreases, the charge‐transfer efficiency increases accordingly. The P(NIPAM‐co‐AA)/AgNPs hybrid microgel particles were thermoresponsive and their behavior completely reversible with several heating/cooling cycles.magnified image
Hierarchical Nanoporous Structures by Self‐Assembled Hybrid Materials Based on Block Copolymers
Authors: Fahmi Amir , Pietsch Torsten , Gindy Nabil 
Published: October 2007

AbstractHierarchical nanoporous structures are fabricated by adsorption of micelles of diblock copolymer‐templated Au‐nanoparticles onto a hydrophilic solid substrate. Gold nanoparticles are prepared using micelles (19 nm) of polystyrene‐block‐poly(4‐vinylpyridine) (PS‐b‐P4VP) as nanoreactors. Deposition of thin films of the micellar solution, modified with a non‐selective solvent (THF), on hydrophilic surfaces leads to the formation of hierarchical nanoporous morphologies. The thin films exhibit two different pore diameters and a total pore density of 15 × 108 holes per cm2. The structure was analyzed in terms of topography and chemical composition using AFM, TEM and XPS measurements. The PS‐b‐P4VP template was subsequently removed by oxygen plasma etching, to leave behind metallic nanopores that mimic the original thin film morphology.magnified image
A Template‐Free Route to Polypyrrole Nanofibers
Authors: Tran Henry D. , Shin Koo , Hong Won G. , D'Arcy Julio M. , Kojima Robert W. , Weiller Bruce H. , Kaner Richard B. 
Published: October 2007

AbstractA template‐free method for the production of polypyrrole nanofibers is presented. By adding a small amount of bipyrrole into the oxidative polymerization of pyrrole, a drastic change in the morphology of the observed material is observed from large, granular particles to nanofibrils with an average diameter of 20 nm. This simple procedure allows for the production of polypyrrole nanofibers without the presence of surfactants or other structural directing agents. The polypyrrole nanofibers can form stable water dispersions which can be cast into films of sufficient quality to function as chemical sensors for analytes such as ammonia.magnified image
Overlapping Schwarz waveform relaxation method for the solution of the convection–diffusion equation
Authors: Daoud Daoud S. 
Published: October 2007

AbstractIn this article we study the convergence of the overlapping Schwarz wave form relaxation method for solving the convection–diffusion equation over multi‐overlapped subdomains. It is shown that the method converges linearly and superlinearly over long and short time intervals, and the convergence depends on the size of the overlap. Numerical results are presented from solving specific types of model problems to demonstrate the convergence and the role of the size of the overlap. Copyright © 2007 John Wiley & Sons, Ltd.
Infinite boundary elements for electromagnetics
Authors: Chadwick Edmund 
Published: October 2007

AbstractConsider a two‐dimensional plane wave transverse magnetic mode scattering from a perfectly electric conducting ground plane. Let the ground plane be of infinite extent and comprise two regions, a near field and a far field. In the far field, let the ground plane be flat and let us choose the co‐ordinates (x, y) such that it lies on the axis y=0. Over the interior region, let the profile of the ground plane change such that it can lie partially above and also partially below the axis y=0. Finally, let us assume that the source of the excitation lies above the ground plane.To model this general class of problems, a method of moments electric field integral equation formulation is proposed which uses infinite boundary elements to model the far field and boundary elements to model the near field. In the far field, the field variable is approximated by the highest order terms in the far‐field asymptotic expansion. The integrals over the infinite boundary elements are infinite in extent and contain oscillatory terms and hence require special integration rules.The formulation is tested for the specific problem of a semi‐circular cylindrical protrusion of radius a lying above an infinite flat ground plane, such that ka=1 where k is the wave number. This problem is chosen because it has an analytic solution in the form of a Bessel function expansion; hence, the accuracy of the formulation can be tested. In particular, the radar cross section results for various angles of incidence of the plane wave source are calculated and compared with analytic results. Copyright © 2007 John Wiley & Sons, Ltd.
Superconvergence and stability for boundary penalty techniques of finite difference methods
Authors: Li Zi‐Cai , Huang Hung‐Tsai , Huang Jin 
Published: October 2007

AbstractThe finite difference method (FDM) is used for Dirichlet problems of Poisson's equation, and the Dirichlet boundary condition is dealt with by boundary penalty techniques. Two penalty techniques, penalty‐integrals and penalty‐collocations (i.e., fixing), are proposed in this paper. The error bounds in the discrete H1 norm and the infinite norms are derived. The stability analysis is based on the new effective condition number (Cond_eff) but not on the traditional condition number (Cond). The bounds of Cond_eff are explored to display that both the penalty‐integral and the penalty‐collocation techniques have good stability; the huge Cond is misleading. Since the penalty‐collocation technique (i.e., the fixing technique) is simpler, it has been applied in engineering problem for a long time. It is worthy to point out that this paper is the first time to provide a theoretical justification for such a popular penalty‐collocation (fixing) technique. Hence the penalty‐collocation is recommended for dealing with the complicated constraint conditions such as the clamped and the simply support boundary conditions of biharmonic equations. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2008
Pronounced bilateral asymmetry of the complete upper extremity: a case from the early Neolithic Baikal, Siberia
Authors: Lieverse A. R. , Metcalf M. A. , Bazaliiskii V. I. , Weber A. W. 
Published: October 2007

AbstractAn adult male skeleton from the early Neolithic cemetery of Shamanka II on the south coast of Lake Baikal (Siberia, Russia) presents one of most striking examples of upper limb bilateral asymmetry documented without obvious indicators of skeletal pathology or trauma to the afflicted arm. The condition is noteworthy not only for its severity, with asymmetry values as high as 89.5%, but also for its involvement of the whole upper extremity, from clavicle to manual phalanges. The lack of any demonstrable hypertrophy on the unaffected left arm, and the clear evidence of extensive hypotrophy/atrophy on the right, leave little doubt that this asymmetry has a pathological or traumatic basis rather than a functional (activity‐induced) one. It most likely reflects paralysis or paresis of the entire right arm resulting from complete brachial palsy incurred prior to the attainment of skeletal maturity in that limb. Copyright © 2007 John Wiley & Sons, Ltd.
p53 and Mdm2: not all cells are equal
Authors: Coates PJ 
Published: October 2007

AbstractThe human TP53 gene is well known as a tumour suppressor. Less well appreciated are the potential roles of p53 in regulating postnatal development and the cell‐type specific effects of p53. In this issue of the Journal of Pathology, Lozano and colleagues show that p53 has the ability to block progenitor cell expansion in haematopoiesis and spermatogenesis but not in specific epithelial tissues. These data challenge the view that p53 acts equally in all cell types and have important implications for the applicability of p53 therapeutics in the treatment of human cancers. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.