bluuebunny/crossref_metadata_2025_split huggingface dataset:
In situ temperature measurements provide new insight into the performance of jet grouting
Authors: Brandstätter C. , Lackner R. , Mang H. A. 
Published: October 2005

In this paper, a new approach for the determination of properties of soil improved by means of jet grouting is proposed. It is characterised by the combination of in situ temperature measurements and a material model for early-age cement-based materials. The latter allows the simulation of the thermochemical problem governing the hydration process. The deviation between the given temperature measurements and the numerical results is minimised by adapting the unknown parameters—the radius of the jet-grouted column and the unknown cement content in the jet-grouted soil. The parameter set yielding the lowest deviation provides an estimate for the radius of the jet-grouted column and the cement content of the jetgrouted soil. The application of the proposed mode of parameter identification to a jet-grouting construction site in Vienna is presented at the end of the paper. Dans cet exposé, nous proposons une nouvelle approche pour déterminer les propriétés d'un sol amélioré par injection de ciment sous pression. Elle se caractérise par une combinaison de mesures de température in situ et par une modélisation des matériaux à base de ciment de la première époque. Cette dernière permet la simulation du problème thermochimique gouvernant le processus d'hydratation. Nous minimisons la déviation entre les mesures de températures données et les résultats numériques en adaptant les paramètres non connus ' c'est-à-dire le rayon de la colonne cimentée sous pression et la teneur inconnue en ciment dans le sol cimenté sous pression. Le lot de paramètres donnant la déviation la plus basse donne une estimation du rayon de la colonne cimentée sous pression et de la teneur en ciment du sol cimenté sous pression. Nous présentons dans cet exposé l'application du mode proposé d'identification de paramètres à un site de construction à cimentation sous pression à Vienne.
Fluorescence Regeneration as a Signaling Principle for Choline and Carnitine Binding: A Refined Supramolecular Sensor System Based on a Fluorescent Azoalkane
Authors: Bakirci H. , Nau W. M. 
Published: October 2005

AbstractThe fluorescent azoalkane, 2,3‐diazabicyclo[2.2.2]oct‐2‐ene (DBO), forms inclusion complexes with p‐sulfonatocalix[4]arene (CX4). The binding constants are on the order of 103 M–1 in water. The addition of CX4 to DBO solutions results in an efficient fluorescence quenching (up to 90 %). This supramolecular system can be used as a truly water‐soluble sensor system to signal the binding of organic ammonium ions over a large pH range. Addition of choline and carnitine derivatives and tetraalkylammonium ions results in regeneration of this fluorescence, from which the binding constants (KC = 103–105 M–1) are calculated by means of a competitive complexation model. Electrostatic effects are observed, namely, a more‐than‐one order of magnitude weaker binding of the carnitines in neutral solution.
Visualization and in situ analysis of leukocyte trafficking into the ankle joint in a systemic murine model of rheumatoid arthritis
Authors: Gál István , Bajnok Éva , Szántó Sándor , Sarraj Bara , Glant Tibor T. , Mikecz Katalin 
Published: October 2005

AbstractObjectiveTo describe the kinetics of leukocyte migration into a distal joint during the development of chronic inflammation in a murine model of rheumatoid arthritis (RA), to identify leukocyte subpopulations recruited in the synovial vessels, and to test in real time the effects of an antiinflammatory compound on leukocyte–endothelial cell interactions in the arthritic joint.MethodsWe used intravital video microscopy (IVM), which was adapted to the microcirculation of the mouse ankle, to monitor the kinetics of leukocyte–endothelium interactions (rolling and firm adhesion) during the onset and progression of proteoglycan‐induced arthritis (PGIA), a chronic autoimmune model of RA. Subpopulations of rolling and adherent leukocytes were identified by in vivo immunostaining. Leukocyte extravasation into the ankle joint was verified histologically.ResultsBetween the onset of arthritis and the beginning of the destructive phase of PGIA, we found a steady increase in the number of leukocytes that exhibited firm adherence to the endothelium of synovial vessels, which clearly underscores the chronic, self‐perpetuating character of joint inflammation in this autoimmune model. We showed, however, that granulocytes, and not T cells, constituted the major cell population that was continuously recruited to the inflamed ankle. Using IVM, we could detect instant changes in leukocyte adhesion behavior in the synovial vessels of the arthritic joint upon administration of a compound that antagonizes leukocyte rolling.ConclusionIVM of the microcirculation of the mouse ankle could become an essential tool for investigating the mechanisms that regulate leukocyte migration to the joint in systemic models of RA as well as for preclinical testing of antiinflammatory therapies.
Optimizing imaging after coarctation stenting: The clinical utility of multidetector computer tomography
Authors: Sridharan Shankar , Yates Robert , Taylor Andrew M. 
Published: October 2005

AbstractFollowing stenting for coarctation of the aorta, it can be difficult to image the stent adequately using cross‐sectional echocardiography. Unless there is marked clinical concern regarding stent patency, repeat cardiac catheterization is not warranted. Multidetector computed tomography (MDCT) is a useful alternative imaging modality. We report a case that highlights the clinical utility of MDCT for imaging patients who have had stenting of aortic coarctation. MDCT clearly revealed stent fracture as the cause of late stent failure and recoarctation. © 2005 Wiley‐Liss, Inc.
Long‐term disease‐free survival of patients with radically resected thymomas
Authors: Claudio Mineo Tommaso , Ambrogi Vincenzo , Mineo Davide , Baldi Alfonso 
Published: October 2005

AbstractBACKGROUNDDespite radical surgical resection, thymomas often recur. The objective of the current retrospective study was to investigate the prognostic relevance of the expression of cell‐cycle proteins in these neoplasms to formulate a possible therapeutic surveillance strategy for the prevention of recurrence.METHODSThe authors retrospectively reviewed the main clinicopathologic factors, including the World Health Organization (WHO) classification, of patients with thymoma who had undergone radical surgical resection. Specimens were studied using immunohistochemistry and the expression of cell‐cycle proteins (i.e., p21, p27, and p53) was assessed. Univariate and multivariate analysis of predicting survival prognostic factors were performed.RESULTSThe authors analyzed 88 patients with thymoma who underwent radical surgical resection at the study institution. According to the Masaoka staging system, 41 patients had Stage I disease, 31 patients had Stage II disease, and 16 patients had Stage III disease. There were 24 tumor recurrences (27.3%), 4 of which were local, 16 of which were distant intrathoracic, and 4 of which were extrathoracic. The second radical resection provided a disease‐free survival rate that was similar to the first. Only Masaoka stage (P = 0.001), WHO classification (P=0.001), high expression of p53 (P=0.03), and low expression of p21 (P=0.02) and p27 (P=0.001) were found to be correlated with a reduced disease‐free survival. Low p27 expression was found to be the most significant predictive factor of a short disease‐free survival (P=0.001), especially when associated with low p21 expression and high p53 expression (P=0.0001).CONCLUSIONSLong‐term disease‐free survival in thymoma patients treated with radical surgical resection was found to be correlated with Masaoka stage, WHO classification, and expression of cell‐cycle proteins, with the latter found to be the most significant predictive factor. Functional cooperation between cell‐cycle proteins might constitute another level of regulation in tumor growth. More careful surveillance should be adopted whenever there is negative cell‐cycle protein expression. Cancer 2005. © 2005 American Cancer Society.
Two‐grid covolume schemes for elliptic problems
Authors: Wang Cheng , Huang Ziping , Li Likang 
Published: October 2005

AbstractIn this paper, we present and analyse some local and parallel covolume algorithms for second‐order elliptic problems. We first prove some local a priori error estimates for covolume method. With these results, we shall apply the two‐grid strategy to covolume approximation to give two novel covolume algorithms, and show that the convergence rates of these algorithms are optimal in piecewise H1‐norm. Numerical results confirming the theory are also provided. Copyright © 2005 John Wiley & Sons, Ltd.
Solution of the 3D linear hydrodynamic equations using an enhanced eigenfunction approach
Authors: Davies Alan M. 
Published: October 2005

AbstractA method is presented for solving the 3D hydrodynamic equations in homogeneous sea regions using the Galerkin approach in the vertical with a mixed basis set. The basis set is composed of eigenfunctions of the eddy viscosity profile and a fixed function through the vertical, the amplitude of which is related to the externally applied surface wind stress. By this means the high‐shear near‐surface layer, which has previously been difficult to resolve using eigenfunction expansions, is accurately represented in the solution.The computational advantages of this approach compared with other basis functions, in terms of computer time and memory, and the ease of implementation on parallel processors with vector facilities are briefly discussed.The accuracy of the method and the choice of the additional function is demonstrated for the problem of wind‐induced currents in a rectangular sea region.Calculations clearly show that for wind‐induced currents this new approach is significantly more accurate than the ‘classical’ eigenfunction method. Also, the new method retains the advantages of the eigenfunction approach, namely insight into the mechanisms involved and ease of implementation on vector‐parallel computers, together with minimization of computer time and memory.
Numerical solution of the Navier‐Stokes equations using a finite element method
Authors: Mehta R. C. , Jayachandran T. , Sastri V. M. K. 
Published: October 2005

AbstractA finite element algorithm for solving the Navier‐Stokes equations is presented for the analysis of high‐speed viscous flows. The algorithm uses triangular elements. The unsteady equations are integrated to steady state with a Runge‐Kutta time‐marching scheme. A postprocessing artificial dissipation term is introduced to stabilize the computations and to dampen dissipation errors. Numerical results are compared with the calculation of uniform flow on a rectangular region which encounters an embedded oblique shock. A shock/turbulent boundary layer problem is also solved and results are compared with experimental data. It is shown that the postprocessing smoothing term and boundary conditions similar to the finite difference method work well in the present numerical studies.
Multidomain collocation techniques for a viscous compressible flow
Authors: Kjellmert Bo 
Published: October 2005

AbstractThis paper presents a viscous compressible flow problem to which an equilibrium solution, in terms of density and velocity, can be given implicitly by elementary functions. The corresponding initial boundary value problem is solved by time discretization by the Crank‐Nicolson method, Newton linearization and space discretization using multidomain Chebyshev collocation techniques. The physical interval is covered by subintervals of equal length. Each subinterval utilizes the same number of collocation points and each interface consists of one or two points. Six ways of patching are tested. All of them yield solutions with spectral accuracy for a few time steps, but only three are stable in the long run. Details of the density evolution are illustrated.
An improved implicit finite‐difference scheme for boundary‐layer flows
Authors: El‐Shaarawi M. A. I. , Sarhan A. 
Published: October 2005

AbstractThe paper presents a modification to two well‐known non‐iterative implicit finite‐difference schemes for confined and unconfined boundary‐layer‐type flows. The modification aims at improving the accuracy of these schemes by reducing the adverse effect of linearization, which is inherent in both of them. Using the present improved scheme, the same level of accuracy of the results could be obtained with large mesh sizes in the flow direction (coarse grid). The modification is done by adding a local iterative procedure at each computational step in the flow (marching) direction. As an example, to demonstrate the proposed modification, the simple case of developing forced convection in the entry region of concentric annuli has been considered. The results are presented, which prove the applicability of the proposed modification and show its effect on the obtained accuracy and on the required computer time.
A finite element solution of the time‐dependent incompressible Navier–Stokes equations using a modified velocity correction method
Authors: Ren Guang , Utnes Torbjørn 
Published: October 2005

AbstractA finite element solution of the two‐dimensional incompressible Navier–Stokes equations has been developed. The present method is a modified velocity correction approach. First an intermediate velocity is calculated, and then this is corrected by the pressure gradient which is the solution of a Poisson equation derived from the continuity equation. The novelty, in this paper, is that a second‐order Runge–Kutta method for time integration has been used. Discretization in space is carried out by the Galerkin weighted residual method. The solution is in terms of primitive variables, which are approximated by polynomial basis functions defined on three‐noded, isoparametric triangular elements. To demonstrate the present method, two examples are provided. Results from the first example, the driven cavity flow problem, are compared with previous works. Results from the second example, uniform flow past a cylinder, are compared with experimental data.
A method for finite element parallel viscous compressible flow calculations
Authors: Dutto Laura C. , Habashi Wagdi G. , Robichaud Michel P. , Fortin Michel 
Published: October 2005

AbstractThis paper presents the parallelization aspects of a solution method for the fully coupled 3D compressible Navier‐Stokes equations. The algorithmic thrust of the approach, embedded in a finite element code NS3D, is the linearization of the governing equations through Newton methods, followed by a fully coupled solution of velocities and pressure at each non‐linear iteration by preconditioned conjugate gradient‐like iterative algorithms. For the matrix assembly, as well as for the linear equation solver, efficient coarse‐grain parallel schemes have been developed for shared memory machines, as well as for networks of workstations, with a moderate number of processors. The parallel iterative schemes, in particular, circumvent some of the difficulties associated with domain decomposition methods, such as geometry bookkeeping and the sometimes drastic convergence slow‐down of partitioned non‐linear problems.
Minimum drag shape in two‐dimensional viscous flow
Authors: Kim Do Wan , Kim Moon‐uhn 
Published: October 2005

AbstractThe problem of finding the shape of a body with smallest drag in a flow governed by the two‐dimensional steady Navier‐Stokes equations is considered. The flow is expressed in terms of a streamfunction which satisfies a fourth‐order partial differential equation with the biharmonic operator as principal part. Using the adjoint variable approach, both the first‐ and second‐order necessary conditions for the shape with smallest drag are obtained. An algorithm for the calculation of the optimal shape is proposed in which the first variations of solutions of the direct and adjoint problems are incorporated. Numerical examples show that the algorithm can produce the optimal shape successfully.
Biodegradation and bioabsorption innovation of the functionally graded bovine bone–originated apatite with blood permeability
Authors: Akazawa Toshiyuki , Murata Masaru , Sasaki Tomoya , Tazaki Junichi , Kobayashi Masayoshi , Kanno Tohru , Nakamura Katsuo , Arisue Makoto 
Published: October 2005

AbstractBioabsorbable and functionally graded apatite (fg‐HAp) ceramics were designed using bovine bone by the calcination and partial dissolution–precipitation methods. The fg‐HAp ceramics that were developed had gradual distributions of the degree of crystallinity and the grain size of single‐phase hydroxyapatite from the surface layer of the pore wall to the bulk structure region. Calcination at 1073K gave a specific surface area of 30 m2 · g−1 and porosities of 60–80%. The pore structure of the fg‐HAp was classified into two regions: a macro‐pore region (100–600 μm) originating from spongy bone and a micro‐pore region (10–160 nm) related to body fluid permeation and blood permeability. By implantation in subcutaneous tissue of rat, it was confirmed that body fluid permeated the bulk region of the fg‐HAp ceramics through the micro‐pores. The volumetric populations occupied by body fluid were 60% at 4 weeks and 68% at 8 weeks in the ceramics explants, indicating drastic bioabsorption, although the body fluid was found to be immunopositive for an albumin as the main serum protein in blood. On the fg‐HAp ceramics developed here, the bioabsorption rate could be controlled by careful selection of the calcination temperature. These ceramics can be applied as new biomimetic ceramics exhibiting surface and bulk degradations and cellular absorption by giant cells. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Characterization and optimization of experimental variables within a reproducible bladder encrustation model and in vitro evaluation of the efficacy of urease inhibitors for the prevention of medical device‐related encrustation
Authors: Jones David S. , Djokic Jasmina , Gorman Sean P. 
Published: October 2005

AbstractThis study presents a reproducible, cost‐effective in vitro encrustation model and, furthermore, describes the effects of components of the artificial urine and the presence of agents that modify the action of urease on encrustation on commercially available ureteral stents. The encrustation model involved the use of small‐volume reactors (700 mL) containing artificial urine and employing an orbital incubator (at 37°C) to ensure controlled stirring. The artificial urine contained sources of calcium and magnesium (both as chlorides), albumin and urease. Alteration of the ratio (% w/w) of calcium salt to magnesium salt affected the mass of encrustation, with the greatest encrustation noted whenever magnesium was excluded from the artificial urine. Increasing the concentration of albumin, designed to mimic the presence of protein in urine, significantly decreased the mass of both calcium and magnesium encrustation until a plateau was observed. Finally, exclusion of urease from the artificial urine significantly reduced encrustation due to the indirect effects of this enzyme on pH. Inclusion of the urease inhibitor, acetohydroxamic acid, or urease substrates (methylurea or ethylurea) into the artificial medium markedly reduced encrustation on ureteral stents. In conclusion, this study has described the design of a reproducible, cost‐effective in vitro encrustation model. Encrustation was markedly reduced on biomaterials by the inclusion of agents that modify the action of urease. These agents may, therefore, offer a novel clinical approach to the control of encrustation on urological medical devices. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Hemocompatibility of low‐friction boron–carbon–nitrogen containing coatings
Authors: Maitz M. F. , Gago R. , Abendroth B. , Camero M. , Caretti I. , Kreissig U. 
Published: October 2005

AbstractMechanical heart valves are exposed to extreme mechanical demands, which require a surface showing not only nonhaemostatic properties, but also wear resistance and low friction. As alternative to different forms of amorphous carbon (a‐C), so‐called diamond‐like carbon (DLC), the suitability of boron carbonitride (BCN) coatings is tested here for hemocompatible coatings. They have similar mechanical properties like a‐C surfaces, but superior chemical stability at ferrous substrates or counterparts. BCN films with different nitrogen content were compared with hydrogenated a‐C films regarding their mechanical properties, surface energy, adsorption of albumin and fibrinogen, blood platelet adherence, and activation of the contact system of the clotting cascade and kinin system. Similar mechanical properties and biological response have been found in the BCN films with respect to a‐C, indicating the potential of these coatings for biomedical applications. The increase in the crystallinity and tribological properties of the BCN samples with a higher incorporation of N was also followed by a lower protein adsorption and low activation of the contact system, but an increased adherence of thrombocytes. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
GROMACS: Fast, flexible, and free
Authors: Van Der Spoel David , Lindahl Erik , Hess Berk , Groenhof Gerrit , Mark Alan E. , Berendsen Herman J. C. 
Published: October 2005

AbstractThis article describes the software suite GROMACS (Groningen MAchine for Chemical Simulation) that was developed at the University of Groningen, The Netherlands, in the early 1990s. The software, written in ANSI C, originates from a parallel hardware project, and is well suited for parallelization on processor clusters. By careful optimization of neighbor searching and of inner loop performance, GROMACS is a very fast program for molecular dynamics simulation. It does not have a force field of its own, but is compatible with GROMOS, OPLS, AMBER, and ENCAD force fields. In addition, it can handle polarizable shell models and flexible constraints. The program is versatile, as force routines can be added by the user, tabulated functions can be specified, and analyses can be easily customized. Nonequilibrium dynamics and free energy determinations are incorporated. Interfaces with popular quantum‐chemical packages (MOPAC, GAMES‐UK, GAUSSIAN) are provided to perform mixed MM/QM simulations. The package includes about 100 utility and analysis programs. GROMACS is in the public domain and distributed (with source code and documentation) under the GNU General Public License. It is maintained by a group of developers from the Universities of Groningen, Uppsala, and Stockholm, and the Max Planck Institute for Polymer Research in Mainz. Its Web site ishttp://www.gromacs.org. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1701–1718, 2005