bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of high‐intensity endurance exercise training in the G93A mouse model of amyotrophic lateral sclerosis
Authors: Mahoney Douglas J. , Rodriguez Christine , Devries Michaela , Yasuda Nobuo , Tarnopolsky Mark A. 
Published: March 2004

AbstractThe G93A transgenic mouse has a mutation in copper/zinc superoxide dismutase (CuZnSOD) that results in oxidative stress and motor neuron loss. Endurance exercise training is known to increase antioxidant capacity in skeletal muscle. Therefore, we hypothesized that endurance training may extend onset of disease or survival in the G93A mouse. We examined the effects of high‐intensity endurance exercise training (45 min/day, 5 times/week, progressive increase from 9 to 22 m/min) on disease onset and survival in G93A mice. Endurance training did not affect clinical onset, although it hastened death in male mice (P < 0.05). Endurance‐trained males had a statistically significant decrease in rotarod performance at 112 days (P < 0.05), whereas sedentary males decreased at 119 days (P < 0.05). Endurance‐trained and sedentary females decreased at 126 days and 129 days, respectively (P < 0.05). Female mice lived longer than males (P < 0.05), and there was a trend for hastened clinical onset in males (P = 0.062). We conclude that high‐intensity endurance exercise training does not affect onset of clinical symptoms in G93A mice but hastens a decrease in motor performance and death following onset of clinical symptoms in male mice only. In light of a recent report describing increased survival following low‐intensity endurance training, it appears that training intensity is an important determinant of survival in the G93A mouse. © 2004 Wiley Periodicals, Inc. Muscle Nerve 29: 656–662, 2004
Exon 17 skipping in CLCN1 leads to recessive myotonia congenita
Authors: Chen Lie , Schaerer Martin , Lu Zen H. , Lang Doris , Joncourt Franziska , Weis Joachim , Fritschi Juerg , Kappeler Lilianne , Gallati Sabina , Sigel Erwin , Burgunder Jean‐Marc 
Published: March 2004

AbstractMutations in CLCN1, the gene encoding the ClC‐1 chloride channel in skeletal muscle, lead to myotonia congenita. The effects on the intramembranous channel forming domains have been investigated more than that at the intracellular C‐terminus. We have performed a mutation screen involving the whole CLCN1 gene of patients with myotonia congenita by polymerase chain reaction (PCR), single‐strand conformation polymorphism studies, and sequencing. Two unrelated patients harbored the same homozygous G‐to‐T mutation on the donor splice site of intron 17. This led to the skipping of exon 17, as evidenced by the reverse transcriptase PCR. When the exon 17–deleted CLCN1 was expressed in Xenopus oocytes, no chloride current was measurable. This function could be restored by coexpression with the wild‐type channel. Our data suggest an important role of this C‐terminal region and that exon 17 skipping resulting from a homozygous point mutation in CLCN1 can lead to recessive myotonia congenita. © 2004 Wiley Periodicals, Inc. Muscle Nerve 29: 670–676, 2004
Motor function–muscle strength relationship in spinal muscular atrophy
Authors: Merlini Luciano , Bertini Enrico , Minetti Carlo , Mongini Tiziana , Morandi Lucia , Angelini Corrado , Vita Giuseppe 
Published: March 2004

AbstractThe relationship between motor function and muscle strength in patients with spinal muscular atrophy (SMA) is still controversial. In 120 genetically proven SMA patients, aged 5 years or older, we measured muscle strength in the arms and legs by a hand‐held dynamometer, forced vital capacity by a spirometer, and the time needed to walk 10 m, arise from the floor, and climb steps. SMA patients had markedly reduced muscle strength, approximating 20% of that predicted from age‐ and gender‐matched normative data. Knee extensors were the weakest muscles in SMA patients. The young ambulant SMA patients performed better than adults in all the timed tests and had greater muscle strength on knee extension. This study shows a good relationship between motor ability and muscle strength in SMA and confirms that age‐related loss of function in SMA is due to loss of muscle strength. Muscle Nerve 29: 548–552, 2004
Postcontraction changes of muscle architecture in human quadriceps muscle
Authors: Mahlfeld Konrad , Franke Jörg , Awiszus Friedemann 
Published: March 2004

AbstractMaximal voluntary contraction changes the mechanical properties of skeletal muscle. Using ultrasound, we investigated whether these changes are reflected by changes in muscle architecture in the vastus lateralis muscle of 8 healthy volunteers. The mean pennation angle during the time interval from 3 to 6 min after maximal voluntary contraction (late postcontraction state) was 14.4 ± 1.11° (mean ± SEM) and differed significantly from the precontraction state (16.2 ± 1.39°), but the pennation angle in the early postcontraction state did not change statistically from the precontraction angle. Thus, postcontraction changes of the muscle–tendon interface appeared for 6 min after a maximal contraction, which may be important for biomechanical optimization of force transmission in vivo. Muscle Nerve 29: 597–600, 2004
Concave envelopes of monomial functions over rectangles
Authors: Benson Harold P. 
Published: March 2004

AbstractThe construction of convex and concave envelopes of real‐valued functions has been of interest in mathematical programming for over 3 decades. Much of this interest stems from the fact that convex and concave envelopes can play important roles in algorithms for solving various discrete and continuous global optimization problems. In this article, we use a simplicial subdivision tool to present and validate the formula for the concave envelope of a monomial function over a rectangle. Potential algorithmic applications of this formula are briefly indicated. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004
Compartmentation of glycolysis and glycogenolysis in the perfused rat heart
Authors: Anousis Nick , Carvalho Rui A. , Zhao Piyu , Malloy Craig R. , Sherry A. Dean 
Published: March 2004

AbstractDeveloping methods that can detect compartmentation of metabolic pathways in intact tissues may be important for understanding energy demand and supply. In this study, we investigated compartmentation of glycolysis and glycogenolysis in the isolated perfused rat heart using 13C NMR isotopomer analysis. Rat hearts previously depleted of myocardial glycogen were perfused with 5.5 mm [U‐13C]glucose plus 50 mU/mL insulin until newly synthesized glycogen recovered to new steady‐state levels (∼60% of pre‐depleted values). After a short wash‐out period, the perfusate glucose was then switched to [1‐13C]glucose, and glycolysis and glycogenolysis were stimulated by addition of glucagon (1 μg/ml). A 13C NMR multiplet analysis of the methyl resonance of lactate provided an estimate of pyruvate derived from glucose vs glycogen while a multiplet analysis of the C4 resonance of glutamate provided an estimate of acetyl‐CoA derived from glycolytic pyruvate vs glycogenolytic pyruvate. These two indices were not equivalent and their difference was further magnified in the presence of insulin during the stimulation phase. These combined observations are consistent with functional compartmentation of glycolytic and glycogenolytic enzymes that allows pyruvate generated by these two processes to be distinguished at the level of lactate and acetyl‐CoA. Copyright © 2004 John Wiley & Sons, Ltd.
Brain GABA editing by localized in vivo1H magnetic resonance spectroscopy
Authors: Bielicki G. , Chassain C. , Renou JP. , Farges MC , Vasson MP , Eschalier A. , Durif F. 
Published: March 2004

AbstractEditing of GABA by 1H MRS in a specific brain area is a unique tool for in vivo non‐invasive investigation of neurotransmission disorders. Selective GABA detection is achieved using sequences based on double quantum coherence (DQC). Our pulse sequence makes accurate measurements without artefacts due to spatial localization. The sequence was tested on a phantom solution. The effect of vigabatrin, a specific inhibitor of GABA transaminase, was measured in rat brain and GABA detection was performed in vivo in monkey brain using this procedure. Rats were spilt into two groups. In the control group, the rats had access to water and, in the other group (vigabatrin, VGB, rats), animals were allowed free access to drinking water containing vigabatrin. After 3 weeks of treatment, rats were anesthetized for in vivo NMR spectroscopy investigation. At the end of the experiment, brains were quickly removed, freeze‐clamped and extracted with 4% perchloric acid. One part of the acid extract was used for GABA concentrations assessment by ion exchange chromatography with ninhydrin detection. The second was used for high‐resolution NMR analysis. By chromatography measurements, the GABA concentration was 1.23±0.06 μmol/g for controls, while for vigabatrin‐treated rats the GABA concentration was 4.89±1.60 μmol/g. The NMR in vivo results were closely correlated with the NMR ex vivo (r=0.99, p<0.01) and chromatography results (r=0.98, p<0.01). The correlation between ex vivo results and chromatography results was also high (r=0.99, p<0.001). This pulse sequence performed GABA editing from a 376 μl voxel located on the right basal ganglia area in a non‐human primate brain. This in vivo GABA editing scheme can thus be proposed for accurate measurement of brain GABA concentrations. Copyright © 2004 John Wiley & Sons, Ltd.
1H MRS studies of signals from mobile lipids and from lipid metabolites: comparison of the behavior in cultured tumor cells and in spheroids
Authors: Rosi Antonella , Grande Sveva , Luciani Anna Maria , Barone Piero , Mlynarik Vladimir , Viti Vincenza , Guidoni Laura 
Published: March 2004

Abstract1H magnetic resonance studies on MCF‐7 and HeLa cells were undertaken to reveal differences in lipid and lipid metabolite signals during the growth in culture. High intensity mobile lipid (ML) signals were found during the first days in culture, while afterwards the same signals declined and started increasing again at confluence and at late confluence. At the same time, signals from the lipid metabolite phosphocholine decreased in intensity while signals from glycerophosphocholine in MCF‐7 and from choline in HeLa increased as cells approached confluence. Spectral parameters from actively proliferating and non‐proliferating cells were used to classify cells with respect to the proliferative conditions by means of a multivariate statistical analysis. Furthermore, it was shown that polyunsaturation of mobile lipid chains was lower in the confluent group with respect to the actively proliferating cells. The examination of spectra from suspensions of MCF‐7 spheroids with diameter smaller than 500 μm suggests that cells in spheroids are in condition of lipid metabolism similar to that of confluent cultured cells. Copyright © 2004 John Wiley & Sons, Ltd.
Anisotropic mesh adaptation for numerical solution of boundary value problems
Authors: Dolejší Vít , Felcman Jiří 
Published: March 2004

AbstractWe present an efficient mesh adaptation algorithm that can be successfully applied to numerical solutions of a wide range of 2D problems of physics and engineering described by partial differential equations. We are interested in the numerical solution of a general boundary value problem discretized on triangular grids. We formulate a necessary condition for properties of the triangulation on which the discretization error is below the prescribed tolerance and control this necessary condition by the interpolation error. For a sufficiently smooth function, we recall the strategy how to construct the mesh on which the interpolation error is below the prescribed tolerance. Solving the boundary value problem we apply this strategy to the smoothed approximate solution. The novelty of the method lies in the smoothing procedure that, followed by the anisotropic mesh adaptation (AMA) algorithm, leads to the significant improvement of numerical results. We apply AMA to the numerical solution of an elliptic equation where the exact solution is known and demonstrate practical aspects of the adaptation procedure: how to control the ratio between the longest and the shortest edge of the triangulation and how to control the transition of the coarsest part of the mesh to the finest one if the two length scales of all the triangles are clearly different. An example of the use of AMA for the physically relevant numerical simulation of a geometrically challenging industrial problem (inviscid transonic flow around NACA0012 profile) is presented. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2004.
Multigrid algorithm for the cell‐centered finite difference method II: discontinuous coefficient case
Authors: Kwak Do Y. , Lee Jun S. 
Published: March 2004

AbstractWe consider a multigrid algorithm for the cell centered finite difference scheme with a prolongation operator depending on the diffusion coefficient. This prolongation operator is designed mainly for solving diffusion equations with strong varying or discontinuous coefficient and it reduces to the usual bilinear interpolation for Laplace equation. For simple interface problem, we show that the energy norm of this operator is uniformly bounded by 11/8, no matter how large the jump is, from which one can prove that W‐cycle with one smoothing converges with reduction factor independent of the size of jump using the theory developed by Bramble et al. (Math Comp 56 (1991), 1–34). For general interface problem, we show that the energy norm is bounded by some constant C* (independent of the jumps of the coefficient). In this case, we can conclude W‐cycle converges with sufficiently many smoothings. Numerical experiment shows that even V‐cycle multigrid algorithm with our prolongation works well for various interface problems. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2004.
Normal and tangential continuous elements for least‐squares mixed finite element methods
Authors: Huo‐Yuan Duan , Guo‐Ping Liang 
Published: March 2004

AbstractWe consider a finite element discretization of the primal first‐order least‐squares mixed formulation of the second‐order elliptic problem. The unknown variables are displacement and flux, which are approximated by equal‐order elements of the usual continuous element and the normal continuous element, respectively. We show that the error bounds for all variables are optimal. In addition, a field‐based least‐squares finite element method is proposed for the 3D‐magnetostatic problem, where both magnetic field and magnetic flux are taken as two independent variables which are approximated by the tangential continuous and the normal continuous elements, respectively. Coerciveness and optimal error bounds are obtained. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2004.
Coupling harmonic functions‐finite elements for solving the stream function‐vorticity Stokes problem
Authors: Abboud T. , Salaün M. , Salmon S. 
Published: March 2004

AbstractWe consider the bidimensional Stokes problem for incompressible fluids in stream function‐vorticity form. The classical finite element method of degree one usually used does not allow the vorticity on the boundary of the domain to be computed satisfactorily when the meshes are unstructured and does not converge optimally. To better approach the vorticity along the boundary, we propose that harmonic functions obtained by integral representation be used. Numerical results are very satisfactory, and we prove that this new numerical scheme leads to an optimal convergence rate of order 1 for the natural norm of the vorticity and, under higher regularity assumptions, from 3/2 to 2 for the quadratic norm of the vorticity. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2004.
A simple Dufort‐Frankel‐type scheme for the Gross‐Pitaevskii equation of Bose‐Einstein condensates on different geometries
Authors: Lai Ming‐Chih , Huang Chung‐Yin , Lin Te‐Sheng 
Published: March 2004

AbstractWe develop a simple Dufort‐Frankel‐type scheme for solving the time‐dependent Gross‐Pitaevskii equation (GPE). The GPE is a nonlinear Schrödinger equation describing the Bose‐Einstein condensation (BEC) at very low temperature. Three different geometries including 1D spherically symmetric, 2D cylindrically symmetric, and 3D anisotropic Cartesian domains are considered. The present finite difference method is explicit, linearly unconditional stable and is able to handle the coordinate singularities in a natural way. Furthermore, the scheme is time reversible and satisfies a discrete analogue of density conservation law. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2004
Numerical stability of the BEM for advection‐diffusion problems
Authors: Peratta Andrés , Popov Viktor 
Published: March 2004

AbstractA boundary element method (BEM) approach has been developed to solve the time‐dependent 1D advection‐diffusion equation. The 1D solution is part of a 3D numerical scheme for solving advection‐diffusion (AD) problems in fractured porous media. The full 3D scheme includes a 3D solution for the porous matrix, which is coupled with a 2D solution for fractures and a 1D solution for fracture intersections. As the hydraulic conductivity of the fracture intersections is usually higher than the hydraulic conductivity of the fractures and by at least one order of magnitude higher than the hydraulic conductivity of the porous matrix, the fastest flow and solute transport occurs in the fracture intersections. Therefore it is important to have an accurate and stable 1D solution of the transient AD problems. This article presents two different 1D BEM formulations for solution of the AD problems. The particular advantage of these formulations is that they provide one of the most straightforward and simplest ways to couple multiple intersecting 2D Boundary Element problems discretized with linear discontinuous elements. Both formulations are tested and compared for accuracy, stability, and consistency. The analysis helps to select the more suitable formulations according to the properties of the problem under consideration. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2004
Uniform stability of spectral nonlinear Galerkin methods
Authors: He Yinnian , Li Kaitai , Zhao Chunshan 
Published: March 2004

AbstractThis article provides a stability analysis for the backward Euler schemes of time discretization applied to the spatially discrete spectral standard and nonlinear Galerkin approximations of the nonstationary Navier‐Stokes equations with some appropriate assumption of the data (λ, u0, f). If the backward Euler scheme with the semi‐implicit nonlinear terms is used, the spectral standard and nonlinear Galerkin methods are uniform stable under the time step constraint Δt ≤ (2/λλ1). Moreover, if the backward Euler scheme with the explicit nonlinear terms is used, the spectral standard and nonlinear Galerkin methods are uniform stable under the time step constraints Δt = O(λ) and Δt = O(λ), respectively, where λ ≤ λ, which shows that the restriction on the time step of the spectral nonlinear Galerkin method is less than that of the spectral standard Galerkin method. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2004
A dual‐reciprocity boundary element solution of a generalized nonlinear Schrödinger equation
Authors: Ang Whye‐Teong , Ang Keng‐Cheng 
Published: March 2004

AbstractA time‐stepping dual‐reciprocity boundary element method is presented for the numerical solution of an initial‐boundary value problem governed by a generalized non‐linear Schrödinger equation. To test the method, two specific problems with known exact solutions are solved. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 20, 2004.
Modified chitosan III, superabsorbency, salt‐ and pH‐sensitivity of smart ampholytic hydrogels from chitosan‐g‐PAN
Authors: Mahdavinia G. R. , Zohuriaan‐Mehr M. J. , Pourjavadi A. 
Published: March 2004

AbstractPolyacrylonitrile (PAN) grafted chitosan was prepared by ceric‐initiated graft polymerization of acrylonitrile onto chitosan in a homogenous medium. The copolymer chitosan‐g‐PAN product was then hydrolyzed to yield a novel smart hydrogel (H‐chitoPAN) with superabsorbing properties. The influence of add‐on values as well as temperature and time of hydrolysis of the initial chitosan‐g‐PAN on swelling behavior of the hydrogel was evaluated in water and various salt solutions. The swelling kinetics of the superabsorbing hydrogel was studied as well. The hydrogels exhibited ampholytic and pH‐sensitivity characteristics. Several sharp swelling changes were observed in lieu of pH variations in a wide range (pH 2–13). The swelling variations were explained according to swelling theory based on the hydrogel chemical structure. Superabsorbency, pH‐ and salt‐sensitivity of the chitosan‐based hydrogel was briefly compared with the classical starch‐based superabsorbent, H‐SPAN. The pH‐reversibility and on–off switching behavior of the intelligent H‐chitoPAN hydrogels makes them good candidates for considering as potential drug carries. Copyright © 2004 John Wiley & Sons, Ltd.
Results of treatment of fifty‐six patients with localized retroperitoneal and pelvic rhabdomyosarcoma: A report from The Intergroup Rhabdomyosarcoma Study‐IV, 1991–1997
Authors: Raney R. Beverly , Stoner Julie A. , Walterhouse David O. , Andrassy Richard J. , Donaldson Sarah S. , Laurie Fran , Meyer William H. , Qualman Stephen J. , Crist William M. 
Published: March 2004

AbstractBackgroundWe reviewed 56 IRS‐IV patients with localized rhabdomyosarcoma [RMS] of the retroperitoneum/pelvis to assess outcome and prognostic factors, including the value of initially excising ≥50% of the tumor (debulking) before chemotherapy.MethodsPatients had embryonal RMS [N=38], alveolar RMS [N = 7], RMS not otherwise specified [NOS, N = 7], or undifferentiated sarcoma [N = 4]. Fifteen patients were debulked; 41 patients were biopsied. All received VAC; most received radiotherapy.ResultsEstimated 5‐year failure‐free survival [FFS] and overall survival rates were 70 and 75%, respectively. FFS rates were better for patients <10 years old and those with embryonal RMS compared to alveolar RMS/undifferentiated sarcoma. After adjusting for age and histological differences, FFS was better for patients whose tumor was debulked prior to beginning therapy [P = 0.02].ConclusionsThese results are superior to those of previous protocols for patients with RMS of the retroperitoneum/pelvis. Initial excision of ≥50% of the tumor may be associated with increased FFS. © 2004 Wiley‐Liss, Inc.
Second neoplasms after treatment of childhood cancer in Slovenia
Authors: Jazbec Janez , Ećimović Patricija , Jereb Berta 
Published: March 2004

AbstractBackgroundThe number of long time survivors of childhood cancer treatment is constantly increasing over the last decades as a result of advances in diagnosis and treatment. The occurrence of second neoplasms is one of most serious late effects observed in cancer survivors.MethodsThe risk of secondary neoplasm was studied in a cohort of 1,577 patients treated for childhood cancer registered in the Cancer Registry of Slovenia (CRS) between 1961 and 2000. The time at risk was defined from the date of diagnosis of first malignancy to the time of death or the end of the study.ResultsThe most frequent primary malignancies were: acute leukemia 28.5%, central nervous system (CNS) tumors 21.3%, and lymphomas 16.6%. Median observation time was 7.8 years. Forty‐eight patients developed second neoplasms. CNS tumors, acute leukemias, and thyroid carcinoma were most frequent second neoplasms. The cumulative risk for second neoplasm in the entire cohort was 0.06% at 5 years, 5.1% at 15 years, and 12.6% at 25 years after diagnosis of first cancer. The overall survival after second neoplasm was 65% 10 years after the diagnosis of second neoplasm.ConclusionsPatients after treatment of childhood cancer are at special risk for subsequent neoplasms and long‐term follow‐up is mandatory. © 2004 Wiley‐Liss, Inc.