bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inside‐out vein graft and inside‐out artery graft in rat sciatic nerve repair
Authors: Barcelos Alécio Santos , Rodrigues Antonio Castro , Silva Maeli Dal Pai , Padovani Carlos R. 
Published: March 2003

AbstractAlthough veins and arteries present similar wall structures, there are differences which may be relevant in peripheral nerve reconstruction. Inside‐out vein grafts (IOVG) have been satisfactorily used to repair both motor and sensitive nerves. However, the inside‐out artery graft (IOAG) is a new technique and not fully investigated. Our study presents comparative morphological data on nerve regeneration achieved with IOVG and IOAG in the repair of Wistar rat sciatic nerves. Jugular veins and aorta arteries were harvested from donor animals and used “inside‐out” to bridge a 10‐mm gap. Animals were sacrificed at 10 weeks to evaluate nerve regeneration. Both techniques presented great variability in nervous tissue, though some animals showed satisfactory results. Different intensities of scarring processes might have interfered with nerve regeneration. Although IOVG and IOAG techniques showed similar morphometric results, in general, IOVG presented a closer‐to‐normal nerve organization than IOAG. © 2003 Wiley‐Liss, Inc. MICROSURGERY 23:66–71 2003
Shape sensitivity of a plane crack front
Authors: Kovtunenko Victor A. 
Published: March 2003

AbstractThe 3D‐elasticity model of a solid with a plane crack under the stress‐free boundary conditions at the crack is considered. We investigate variations of a solution and of energy functionals with respect to perturbations of the crack front in the plane. The corresponding expansions at least up to the second‐order terms are obtained. The strong derivatives of the solution are constructed as an iterative solution of the same elasticity problem with specified right‐hand sides. Using the expansion of the potential and surface energy, we consider an approximate quadratic form for local shape optimization of the crack front defined by the Griffith criterion. To specify its properties, a procedure of discrete optimization is proposed, which reduces to a matrix variational inequality. At least for a small load we prove its solvability and find a quasi‐static model of the crack growth depending on the loading parameter. Copyright © 2003 John Wiley & Sons, Ltd.
The Milne problem for the linear Fokker–Planck operator with a force term
Authors: Lucquin‐Desreux Brigitte 
Published: March 2003

AbstractThis paper deals with the mathematical analysis of the linear stationary Fokker–Planck equation in a half‐space (also called ‘Milne’ problem), in presence of an external electrostatic force field. We prove existence, uniqueness and asymptotic properties of the solution. Copyright © 2003 John Wiley & Sons, Ltd.
Combined far‐ield operators in electromagnetic inverse scattering theory
Authors: Cakoni Fioralba , Colton David 
Published: March 2003

AbstractWe consider the inverse scattering problem of determining the shape of a perfect conductor D from a knowledge of the scattered electromagnetic wave generated by a time‐harmonic plane wave incident upon D. By using polarization effects we establish the validity of the linear sampling method for solving this problem that is valid for all positive values of the wave number. We also show that it suffices to consider incident directions and observation angles that are restricted to a limited aperture. Copyright © 2003 John Wiley & Sons, Ltd.
Leaky and surface waves in multilayered laterally‐shielded microstrip transmission lines
Authors: Gómez Tornero J. L. , Álvarez Melcón A. 
Published: March 2003

AbstractIn this paper the leakage effects in open laterally‐shielded multilayered microstrip transmission lines are investigated. Potential solutions are often reported to be difficult to find, since they are located in the complex propagating factor plane. To overcome this problem, a novel iterative algorithm is implemented to relate the solutions in the real axis of closed transmission lines with their corresponding complex open structure modes. The problem of modeling the leaky behavior of the open top wall is introduced, and a mathematical and physical explanation of the solutions is proposed. The advantage of this new technique is that it allows us to easily track the leaky solutions to their final location in the complex plane. Results are presented, including the field and power patterns associated to leaky waves, showing that the derived technique is indeed effective for the study of the complex modes excited in this type of structures. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 88–93, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10832
Artificial neural networks for calculating the input resistance of circular microstrip antennas
Authors: Guney Kerim , Sarıkaya Nurcan 
Published: March 2003

AbstractA method based on artificial neural networks (ANNs) for calculating the input resistance of circular microstrip patch antennas is presented. The Levenberg–Marquardt algorithm is used to train the networks. The theoretical input resistance results obtained by using this method are in very good agreement with the experimental results available in the literature. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 107–111, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10838
Small helical antenna for the applications of the dual ISM bands
Authors: Wang Chien‐Jen 
Published: March 2003

AbstractA new design of a miniaturized multilayer ceramic (MLC) antenna is proposed and presented for the applications of the dual ISM bands (hyper LAN and WLN). The antenna‐size reduction is achieved by folding the simple microstrip monopole around a low‐temperature co‐fired ceramic (LTCC) substrate. This paper presents measured data to show that the 10‐dB bandwidths achieved were 180 MHz and 750 MHz at 2.4 GHz and 5.2 GHz, respectively. The co‐polarization far‐field radiation patterns of the chip antenna are quasi‐omnidirectional at 2.4 GHz and 5.2 GHz. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 140–142, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10848
Theoretically obtained dispersion characteristics of an annular waveguide with a guiding region cross section bounded by two hypocycloidal loops
Authors: Singh Vivek , Prasad B. , Ojha S. P. 
Published: March 2003

AbstractThis article presents a theoretical analysis of the modal dispersion curves of an annular waveguide with a core cross section bounded by two hypocycloids. This cross section can be conceived as having the shape of a distorted annular square and leads to a tolerance study of deformation in an annular square waveguide. We take a new and appropriate coordinate system (ξ, η, z) for the proposed geometry and impose boundary conditions under the weak guidance approximation. The characteristic equation is then derived analytically. Finally, we show some numerical results in the form of modal dispersion curves. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 142–145, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10849
Fiber Bragg grating accelerometer with temperature insensitivity
Authors: Zhu Yinian , Shum Ping , Lu Chao , Lacquet Beatrys M. , Swart Pieter L. , Spammer Stephanus J. 
Published: March 2003

AbstractA cantilever beam and fiber Bragg grating are used to measure acceleration. The output signal is insensitive to temperature variations from −20°C to 40°C, and the output signal fluctuates less than 5% without any temperature compensation schemes. For the experimental system, a linear output range of 8 g can be detected. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 37: 151–153, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10852
Isolation and spectral study of 4‐methyl‐6,8‐dihydroxy‐7H‐benz[de]anthracen‐7‐one
Authors: Wang H. M. , Shi W. , Xu Y. K. , Wang P. , Chen W. , Liu Y. , Lü M. J. , Pa J. Q. 
Published: March 2003

Abstract4‐Methyl‐6,8‐dihydroxy‐7H‐benz[de]anthracen‐7‐one was isolated from the sap of Aloe by column chromatography. Its 1H and 13C NMR spectra were completely assigned by utilizing two‐dimensional 1H‐detected heteronuclear one‐bond (HMQC) and multiple‐bond (HMBC) chemical shift correlation experiments together with 1H–1H COSY and DEPT techniques. These techniques were also valuable in assigning the protons and carbons of those benzanthrone compounds which were previously incompletely reported because of the overlap of proton signals. The molecular structure was elucidated by 2D NMR analysis. The spectral properties (MS, IR and UV) are also presented. Copyright © 2003 John Wiley & Sons, Ltd.
Indirect detection of 31P,X connectivities with proton sensitivity: application of two‐dimensional 31P‐relayed 1H,X correlation spectroscopy
Authors: Gudat Dietrich 
Published: March 2003

AbstractExperiments for 1H‐detected heteronuclear 1H,X correlation spectroscopy with 31P‐relayed coherence transfer are described which allow the indirect detection of δX and nJ(X,P) even in the absence of a direct J(X,H) coupling. The use of these techniques for the assignments of 13C, 15N, and 183W NMR data of organophosphorus compounds is demonstrated. Copyright © 2003 John Wiley & Sons, Ltd.
Complete structural and spectral assignment of oxoisoaporphines by HMQC and HMBC experiments
Authors: Sobarzo‐Sánchez Eduardo , Cassels Bruce K. , Jullian Carolina , Castedo Luis 
Published: March 2003

AbstractThe oxoisoaporphines 2,3‐dihydro‐7H‐dibenzo[de,h]quinolin‐7‐one, 2,3‐dihydro‐5‐methoxy‐7H‐dibenzo [de,h] quinolin‐7‐one, 5‐methoxy‐6‐hydroxy‐2,3‐dihydro‐7H‐dibenzo[de,h]quinolin‐7‐one, 5,6‐dimethoxy‐2,3‐dihydro‐7H‐dibenzo[de,h]quinolin‐7‐one and 5,6‐methylenedi‐oxy‐2,3‐dihydro‐7H‐dibenzo[de,h]quinolin‐7‐one were prepared by cyclization of phenylethylaminophthalides with polyphosphoric acid or by treating 1‐(2‐carboxyphenyl)‐3,4‐dihydroisoquinoline hydrochloride with sulfuric acid at 0 °C. The structures were confirmed and 1H and 13C NMR spectra were completely assigned using a combination of one‐ and two‐dimensional NMR techniques. Copyright © 2003 John Wiley & Sons, Ltd.
Evaluation and treatment of low back pain: An evidence‐based approach to clinical care
Authors: Atlas Steven J. , Nardin Rachel A. 
Published: March 2003

AbstractLow back pain is a common reason for patient visits to a health care provider. For most patients, low back symptoms are nonspecific, meaning that the pain is localized to the back or buttocks and is due to a presumed musculoligamentous process. For patients with radicular leg symptoms, a precise etiology is more commonly identified. The history and physical examination usually provide clues to the uncommon but potentially serious causes of low back pain, as well as to those patients at risk for prolonged recovery. Diagnostic testing should not be a routine part of the initial evaluation, but used selectively based upon the history, examination, and initial treatment response. For patients without significant neurological impairment, initial treatments should include activity modification, nonnarcotic analgesics, and education. For patients whose symptoms are not improving over 2 to 4 weeks, referral for physical treatments is appropriate. A variety of therapeutic options of limited or unproven benefit are available for patients with radicular leg symptoms or chronic low back pain. Patients with radicular pain and little or no neurological findings should receive conservative treatment, but elective surgery is appropriate for those with nerve root compression who are unresponsive to conservative therapy. Muscle Nerve 27: 265–284, 2003
Myopodia (postsynaptic filopodia) participate in synaptic target recognition
Authors: Ritzenthaler Sarah , Chiba Akira 
Published: March 2003

AbstractSynaptic partner cells recognize one another by utilizing a variety of molecular cues. Prior to neuromuscular synapse formation, Drosophila embryonic muscles extend dynamic actin‐based filopodia called “myopodia.” In wild‐type animals, myopodia are initially extended randomly from the muscle surface but become gradually restricted to the site of motoneuron innervation, a spatial redistribution we call “clustering.” Previous experiments with prospero mutant embryos demonstrated that myopodia clustering does not occur in the absence of motoneuron outgrowth into the muscle field. However, whether myopodia clustering is due to a general signal from passing axons or is a result of the specific interactions between synaptic partners remained to be investigated. Here, we have examined the relationship of myopodia to the specific events of synaptic target recognition, the stable adhesion of synaptic partners. We manipulated the embryonic expression of αPS2 integrin and Toll, molecules known to affect synaptic development, to specifically alter synaptic targeting on identified muscles. Then, we used a vital single‐cell labeling approach to visualize the behavior of myopodia in these animals. We demonstrate a strong positive correlation between myopodia activity and synaptic target recognition. The frequency of myopodia clustering is lowered in cases where synaptic targeting is disrupted. Myopodia clustering seems to result from the adherence of a subset of myopodia to the innervating growth cone while the rest are eliminated. The data suggest that postsynaptic cells play a dynamic role in the process of synaptic target recognition. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 31–40, 2003
Differential physiologic responses of α7 nicotinic acetylcholine receptors to β‐amyloid1–40 and β‐amyloid1–42
Authors: Lee Daniel H.S. , Wang Hoau‐Yan 
Published: March 2003

AbstractThe β‐amyloid peptides (Aβ), Aβ1–40 and Aβ1–42, have been implicated in Alzheimer's disease (AD) pathology. Although Aβ1–42 is generally considered to be the pathological peptide in AD, both Aβ1–40 and Aβ1–42 have been used in a variety of experimental models without discrimination. Here we show that monomeric or oligomeric forms of the two Aβ peptides, when interact with the neuronal cation channel, α7 nicotinic acetylcholine receptors (α7nAChR), would result in distinct physiologic responses as measured by acetylcholine release and calcium influx experiments. While Aβ1–42 effectively attenuated these α7nAChR‐dependent physiology to an extent that was apparently irreversible, Aβ1–40 showed a lower inhibitory activity that could be restored upon washings with physiologic buffers or treatment with α7nAChR antagonists. Our data suggest a clear pharmacological distinction between Aβ1–40 and Aβ1–42. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 25–30, 2003
Prefiltration technique via aggregation for constructing low‐density high‐quality factorized sparse approximate inverse preconditionings
Authors: Nikishin A. A. , Yeremin A. Yu. 
Published: March 2003

AbstractThis paper considers a new approach to a priori sparsification of the sparsity pattern of the factorized approximate inverses (FSAI) preconditioner using the so‐called vector aggregation technique. The suggested approach consists in construction of the FSAI preconditioner to the aggregated matrix with a prescribed sparsity pattern. Then small entries of the computed ‘aggregated’ FSAI preconditioning matrix are dropped, and the resulting pointwise sparsity pattern is used to construct the low‐density block sparsity pattern of the FSAI preconditioning matrix to the original matrix. This approach allows to minimize (sometimes significantly) the construction costs of low‐density high‐quality FSAI preconditioners. Numerical results with sample matrices from structural mechanics and thin shell problems are presented. Copyright © 2002 John Wiley & Sons, Ltd.
Strongly non‐local gradient‐enhanced finite strain elastoplasticity
Authors: Geers M. G. D. , Ubachs R. L. J. M. , Engelen R. A. B. 
Published: March 2003

AbstractThis paper presents a gradient plasticity formulation developed in a strongly non‐local format and applicable to ductile failure for finite strain plasticity. The obtained formulation is an extension of a framework proposed by Simo (Computer Methods in Applied Mechanics and Engineering 1988; 66: 199) into the softening and localization regime. The presented model inherits the well‐established regularization properties of its strongly non‐local enrichment and leads to an implicit computational scheme with a consistent tangent operator. Numerical examples are given which illustrate the strongly non‐local character of the formulation, the influence of the type of intrinsic length scale considered, as well as several topics on plastic failure initiation and evolution into the geometrically non‐linear regime. Copyright © 2003 John Wiley & Sons, Ltd.
An analysis of strain localization in a shear layer under thermally coupled dynamic conditions. Part 1: Continuum thermoplastic models
Authors: Armero F. , Park J. 
Published: March 2003

AbstractThe work presented in this two‐part paper investigates the characteristics of strain localization in a one‐dimensional shear layer with thermomechanical softening behaviour. We consider in this first part the case of a classical continuum model characterized with a stress–strain relation incorporating the inelastic effects through plastic strains. The thermomechanical coupling effects in the infinitesimal shear problem of interest here include the thermal softening of the material with the increase of the temperature, and the heat source generated by the plastic work in the equation of conservation of energy. We first present a spectral analysis of the linearized problem, characterizing its stability and well‐posedness. We consider the general problem including a viscoplastic regularization in this coupled thermomechanical context, without neglecting the elastic effects. This analysis identifies, in particular, the ill‐posedness of the local continuum model under certain conditions, most notably in the inviscid problem with strain softening. The coupled thermal effects are shown then not to regularize the coupled problem in these circumstances. The lack of an internal length scale associated with the strain localization is concluded. The analytical closed‐form solution of the full non‐linear problem is also presented for the identified ill‐posed problems, revealing the lack of physical significance of these models in these cases. The implications of this analysis for the finite element simulations in the form of pathologically mesh‐size dependent solutions is also concluded and illustrated with a number of representative numerical simulations. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of particle cracking on elastoplastic behaviour of metal matrix composites
Authors: Sun L. Z. , Liu H. T. , Ju J. W. 
Published: March 2003

AbstractA micromechanics‐based elastoplastic and damage constitutive model is proposed to predict the overall mechanical behaviour of particle‐reinforced metal matrix composites. Unidirectionally aligned spheroidal elastic particles, some of which contain penny‐shaped cracks, are randomly distributed in the elastoplastic metal matrix. These imperfect particles, attributed to progressive particle cracking, are modelled by using the double‐inclusion concept. An ensemble‐volume averaged homogenization procedure is employed to estimate the effective yield function of the damaged composites. The associative plastic flow rule and the hardening law are postulated based on the continuum plasticity theory. The underlying damage evolution of particles is considered in accordance with the Weibull's statistical function to characterize the varying probability of reinforcement cracking. The elastoplastic mechanical behaviour of particulate composites under uniaxial loading conditions is simulated and compared with available experimental results. Copyright © 2003 John Wiley & Sons, Ltd.
Failure analysis of solder joints with a damage‐coupled viscoplastic model
Authors: Wei Y. , Chow C. L. , Neilsen M. K. , Fang H. E. 
Published: March 2003

AbstractThis paper presents failure analysis of solder joints with a damage‐coupled viscoplastic model. A material model is developed to characterize the elasticity, plasticity, creep and damage of solder. A semi‐implicit time‐integration approach is adopted for the numerical implementation of the solder model. This solder model has been implemented into finite element codes developed at Sandia National Laboratories and into the commercial, finite element code ABAQUSTM with its user‐defined material subroutine UMAT. Finite element analyses are performed on solder joints with the new solder constitutive model and mesh dependency of these analyses is investigated. Copyright © 2003 John Wiley & Sons, Ltd.
Time finite elements and error computation for (visco)plasticity with hardening or softening
Authors: Larsson Fredrik , Runesson Kenneth , Hansbo Peter 
Published: March 2003

AbstractIn this paper we investigate the possibility for, and characteristics of, reliable and efficient a posteriori error computation at the integration of the constitutive relations pertinent to (visco)plasticity with softening/hardening. The variational structure admits the use of finite elements in time, which are based on the Discontinuous Galerkin method. An important feature is the possibility to select ‘goal‐oriented’ error measures with great freedom. A key task is to identify and solve an auxiliary problem, that is the dual of the actual (primal) problem. Different strategies for computing the dual solution accurately, yet avoiding excessive cost, are investigated in the paper. In particular, we consider the characteristics at the limit of rate‐independent plasticity. Copyright © 2003 John Wiley & Sons, Ltd.
Dose‐dependence of the effect of nicotine on c‐Fos expression in the hippocampus of young rats
Authors: Jang Mi‐Hyeon , Shin Min‐Chul , Kim Hong , Kim Ee‐Hwa , Kim Chang‐Ju 
Published: March 2003

AbstractIt is generally accepted that nicotine affect learning ability and memory functions, especially during adolescence. c‐Fos is an immediate early gene whose expression is sometimes used as a marker for stimulation‐induced changes in the metabolic activity of neurons. The expression of c‐Fos is induced by a variety of stimuli and expression of c‐fos mRNA in hippocampal regions is used as a marker for neuronal activity. In the present study, the effect of dose‐dependence of the nicotine on the c‐Fos expression in the hippocampus of young rats was investigated via immunohistochemistry. From the present results, the number of Fos‐positive cells in each region of the hippocampus was decreased following treatment with nicotine as dose‐dependently. In addition, it appears that nicotine at low doses does not affect the level of apoptosis in the dentate gyrus of the hippocampus; in contrast, nicotine at high doses seems to enhance apoptosis in the dentate gyrus. Based on the results, it can be suggested that nicotine‐induced suppression on Fos expression in the hippocampus of young rats may be an underlying mechanism of nicotine‐induced disruption of information processing during the adolescence.
The weighted Ritz‐Galerkin method for elliptic boundary value problems on unbounded domains
Authors: Oh Hae‐Soo , Jang Bongsoo , Jou Yichung 
Published: March 2003

AbstractRecently Babus̆ka‐Oh introduced the method of auxiliary mapping (MAM) which efficiently handles elliptic boundary value problems containing singularities. In this paper, a special weighted residue method, the Weighted Ritz‐Galerkin Method (WRGM), is investigated by introducing special weight functions. Together with this method, MAM is modified to yield highly accurate finite element solutions to general elliptic boundary value problems on the exterior of bounded domains at low cost. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 301–326, 2003.