bluuebunny/crossref_metadata_2025_split huggingface dataset:
Review: Biological relevance of disseminated tumor cells in cancer patients
Authors: Riethdorf Sabine , Wikman Harriet , Pantel Klaus 
Published: August 2008

AbstractThe prognosis of cancer patients is largely determined by the occurrence of distant metastases. In patients with primary tumors, this relapse is mainly due to clinically occult micrometastasis present in secondary organs at primary diagnosis but not detectable even with high resolution imaging procedures. Sensitive and specific immunocytochemical and molecular assays enable the detection and characterization of disseminated tumor cells (DTC) at the single cell level in bone marrow (BM) as the common homing site of DTC and circulating tumor cells (CTC) in peripheral blood. Because of the high variability of results in DTC and CTC detection, there is an urgent need for standardized methods. In this review, we will focus on BM and present currently available methods for the detection and characterization of DTC. Furthermore, we will discuss data on the biology of DTC and the clinical relevance of DTC detection. While the prognostic impact of DTC in BM has clearly been shown for primary breast cancer patients, less is known about the clinical relevance of DTC in patients with other carcinomas. Current findings suggest that DTC are capable to survive chemotherapy and persist in a dormant nonproliferating state over years. To what extent these DTC have stem cell properties is subject of ongoing investigations. Further characterization is required to understand the biology of DTC and to identify new targets for improved risk prevention and tailoring of therapy. Our review will focus on breast, colon, lung, and prostate cancer as the main tumor entities in Europe and the United States. © 2008 Wiley‐Liss, Inc.
Perturbation of the chromosomal binding of RCC1, Mad2 and survivin causes spindle assembly defects and mitotic catastrophe
Authors: Ho Chin‐Yee , Wong Chi‐Hang , Li Hoi‐Yeung 
Published: August 2008

AbstractMitotic catastrophe is a form of cell death that results from aberrant mitosis. Currently, the mechanisms involved in this form of cell death remain poorly understood. We found that actinomycin D induces mitotic catastrophe with severe spindle assembly defects. We have studied the nature of three groups of chromosome binding proteins in mitotic cells treated with actinomycin D. We found that actinomycin D reduced the binding affinity of RCC1 to the mitotic chromosome, which led to a reduction of RanGTP level. In addition, Mad2 was not concentrated at the kinetochores, indicating that the mitotic spindle checkpoint was affected. Furthermore, the localization of survivin was altered in cells. These data suggested that chromosomal binding of the mitotic regulators such as RCC1, Mad2 and survivin is essential for mitotic progression. Mitotic chromosomes not only carry the genetic material needed for the newly synthesized daughter cells, but also serve as docking sites for some of the mitotic regulators. Perturbation of their binding to the mitotic chromosome by actinomycin D could affect their functions in regulating mitotic progression thus leading to severe spindle defects and mitotic catastrophe. J. Cell. Biochem. 105: 835–846, 2008. © 2008 Wiley‐Liss, Inc.
Lopinavir impairs protein synthesis and induces eEF2 phosphorylation via the activation of AMP‐activated protein kinase
Authors: Hong‐Brown Ly Q. , Brown C. Randell , Huber Danuta S. , Lang Charles H. 
Published: August 2008

AbstractHIV anti‐retroviral drugs decrease protein synthesis, although the underlying regulatory mechanisms of this process are not fully established. Therefore, we investigated the effects of the HIV protease inhibitor lopinavir (LPV) on protein metabolism. We also characterized the mechanisms that mediate the effects of this drug on elongation factor‐2 (eEF2), a key component of the translational machinery. Treatment of C2C12 myocytes with LPV produced a dose‐dependent inhibitory effect on protein synthesis. This effect was observed at 15 min and was maintained for at least 4 h. Mechanistically, LPV increased the phosphorylation of eEF2 and thereby decreased the activity of this protein. Increased phosphorylation of eEF2 was associated with increased activity of its upstream regulators AMP‐activated protein kinase (AMPK) and eEF2 kinase (eEF2K). Both AMPK and eEF2K directly phosphorylated eEF2 in an in vitro kinase assay suggesting two distinct paths lead to eEF2 phosphorylation. To verify this connection, myocytes were treated with the AMPK inhibitor compound C. Compound C blocked eEF2K and eEF2 phosphorylation, demonstrating that LPV affects eEF2 activity via an AMPK‐eEF2K dependent pathway. In contrast, incubation of myocytes with rottlerin suppressed eEF2K, but not eEF2 phosphorylation, suggesting that eEF2 can be regulated independent of eEF2K. Finally, LPV did not affect PP2A activity when either eEF2 or peptide was used as the substrate. Collectively, these results indicate that LPV decreases protein synthesis, at least in part, via inhibition of eEF2. This appears regulated by AMPK which can act directly on eEF2 or indirectly via the action of eEF2K. J. Cell. Biochem. 105: 814–823, 2008. © 2008 Wiley‐Liss, Inc.
Ozonation of chloronitrobenzenes in aqueous solution: kinetics and mechanism
Authors: Li Bingzhi , Xu Xiangyang , Zhu Liang 
Published: August 2008

AbstractBACKGROUND: Chloronitrobenzenes (ClNBs) are a family of toxic and bio‐resistant organic compounds. Ozone treatment is specifically suitable for partial or complete oxidation of non‐biodegradable components. However, few studies on the decomposition of ClNBs by ozone are available, and kinetics and mechanisms of ClNBs ozonation have not been thoroughly investigated. The kinetics and mechanism of ozonation degradation of ClNBs in aqueous solution were investigated, and the contribution of both molecular ozone and hydroxyl radicals was also evaluated.RESULTS: The results demonstrated that the decomposition of ClNBs was a pseudo‐first‐order reaction with respect to the pollutant concentration and the overall rate constant increased with an increase in pH. It declined, however, with an increase in pollutant and radical scavenger concentration. Furthermore, TOC removal rate was significantly lower than that of ClNBs, but the same order o‐ClNB < m‐ClNB < p‐ClNB was followed. Ozonation could not reduce TOC significantly, p‐chlorophenol, p‐nitrophenol, 2‐chloro‐5‐nitrophenol and 5‐chloro‐2‐nitrophenol were detected as primary degradation intermediates in ozonation of p‐ClNB. Rate constants of the direct reaction between ozone and ClNBs at 25 °C had been found to be lower than 1 M−1S−1. More than 95% of ClNBs removal was due to hydroxyl radical oxidation at pH ≥ 7.CONCLUSION: Advanced oxidation processes may be the preferred choice for the elimination of ClNBs from the environment. Copyright © 2008 Society of Chemical Industry
Enteral nutrition in adult Crohn's disease: Present status and perspectives
Authors: Dupont Benoît , Dupont Claire , Justum Anne‐Marie , Piquet Marie‐Astrid , Reimund Jean‐Marie 
Published: August 2008

AbstractEnteral nutrition has long been a therapeutic alternative often used in adult Crohn's disease patients to obtain remission or clinical response, especially in those not responding to conventional therapy such as corticosteroids. However, the increasing use of immunosuppressors (6‐mercaptopurine and azathioprine, methotrexate,etc.), and the advent of biotherapies (especially anti‐tumor necrosis factor‐alpha (TNF‐α) antibodies), decreased its use in adult Crohn's disease. Nevertheless, enteral nutrition remains of interest in patients presenting concomitant malnutrition (in particular in nonobstructed patients needing surgery), or in those intolerant or who failed to other therapeutics. In addition, recent studies provide data indicating its potential interest in maintenance therapy in selected patients groups. Finally, future research (in particular in the field of immuno‐ or pharmaconutrition) could lead to enteral formula's improvement, with better tolerance and acceptability, as well as increased efficacy.
Dynamic optimization and event location in atmospheric chemistry
Authors: Caboussat Alexandre , Landry Chantal 
Published: August 2008

AbstractA model coupling differential equations and an optimization problem with equality and inequality constraints is described. The first order optimality conditions are coupled with the differential equations to form a differential‐algebraic system. Inequality constraints for the optimization variables induce discontinuities in the first derivatives of the solution in time. Tracking techniques based on sensitivity analysis and second order multistep methods are proposed to locate the discontinuities. Application to the dynamics of organic atmospheric aerosol particles is given to illustrate the detection of the activation of constraints. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solving generalized complex‐symmetric eigenvalue problems arising from resonant MEMS simulations with PETSc
Authors: Koyamaname Tsuyoshi , Govindjee Sanjay 
Published: August 2008

AbstractIn the operation of high frequency resonators in micro electromechanical systems(MEMS), there is a strong need to be able to accurately determine the energy loss rates or alternatively the quality of resonance. The resonance quality is directly related to a designers ability to assemble a high fidelity system response for signal filtering, for example. This has implications on robustness and quality of electronic communication and also strongly influences overall rates of power consumption in such devices – i.e. battery life. An index of the quality of resonance Q is inversely proportional to the amount of energy loss existing in the system, and can be defined in terms of the complex‐valued eigenvalues ω of the system as, . In this presentation, we examine methods for accurately simulating energy loss using the direct modeling of acoustic radiation via perfectly matched layer (PML) technology for 3‐D structures, which results in complex‐symmetric mass and stiffness matrices. Thus it is crucial that one is able to accurately compute eigenvalues of a complex‐symmetric system. 3‐D modeling increases the number of degrees of freedom and complexity in obtaining the solution, resulting in a requirement for more computing power and memory which can only be supplied by parallel computing methods. The simulations are conducted through the MEMS simulation software HiQLab in combination with the parallel numerical libraries PETSc and Trilinos. A modified smoothed aggregation algebraic multigrid method for solving a linear system of equations is combined with a Jacobi‐Davidson method to solve for desired eigenvalues. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The nullspace method for the three‐dimensional Stokes problem
Authors: Le Borne Sabine , Kriemann Ronald 
Published: August 2008

AbstractIn this paper, we present the preconditioned nullspace method for the iterative solution of the three‐dimensional Stokes problem. In the nullspace method, the original saddle point system is reduced to a positive definite problem by representing the solution with respect to a basis of discretely divergence free vectors. The exact, explicit computation of such a basis typically has non‐optimal (storage and computational) complexity. There exist some algorithms that exploit the sparsity of the matrix and work well for two dimensional problems but fail for three dimensions. Here, we will exploit an implicit representation of the nullspace basis which can be computed efficiently also in a three‐dimensional setting, possibly only as an approximation. We will present some numerical results to illustrate the performance of the resulting solution method. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Halley and Newton are one step apart
Authors: Gundersen Geir , Steihaug Trond 
Published: August 2008

AbstractOne of the central problems of scientific computation is the efficient numerical solution of the system of n equations in n unknowns F (x) = 0 where F: Rn → Rn is sufficiently smooth. While Newton's method is usually used for solving such systems, third order methods will in general use fewer iterations than a second order method to reach the same accuracy. However, the number of arithmetic operations per iteration is higher for third order methods than second order methods. In this note we will consider the case where F = ∇f, where f is three times continuously differentiable. We will show that for a large class of sparse problems the ratio of the number of arithmetic operations of a third order method and Newton's method is constant per iteration. It is shown that
equation image
when the structure of the tensor is induced by a general sparse structured Hessian matrix which gives no fill‐ins when we use a direct method to solve a system of linear equations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stochastic modeling of non‐equilibrium multiphase flow in porous media
Authors: Tyagi Manav , Jenny Patrick , Tchelepi Hamdi A. 
Published: August 2008

AbstractNon‐equilibrium phenomena arising from the pore scale dynamics can have considerable effect on the large scale dynamics of multiphase flow in porous media. In such cases, the relative permeabilities and capillary pressure curves are not just simple functions of phase saturations, rather are dynamic functions of space and time. The present work proposes a stochastic approach in which particle mobility can be modelled based on the actual conductance of fluid volume inside a pore space. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Portfolio Improvement by Using the Sharpe Rule and Value‐at‐Risk
Authors: Yu Kwok Wai , Yang Xiao Qi , Wong Heung 
Published: August 2008

AbstractThis study discusses the applications of the Sharpe rule in portfolio measurement and management. It proposes that a portion of the portfolio value should be invested in some other assets for portfolio improvement. By applying the Sharpe rule, it can be determined that new stocks are worthy of adding to the old portfolio if they satisfy a condition, in which the average return rate of these stocks is greater than the return rate of the old portfolio multiplied by the sum of the elasticity of the VaR and 1. One attraction of our approach is diversification. A numerical example in the Hong Kong stock market is presented for illustration. Some experimental results show that a new portfolio with the 'highest' Sharpe ratio can be obtained by adding only a few new assets. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐reflecting boundary conditions for the compressible Euler and Navier‐Stokes equations in the finite volume method
Authors: Kyncl Martin , Pelant Jaroslav , Felcman Jiří 
Published: August 2008

AbstractThe paper is concerned with the numerical implementation of the inlet and outlet boundary conditions in the finite volume method for the solution of the 3D Euler and Navier‐Stokes equations. The explicit time marching procedure is described. The classical Riemann problem is modified for physically relevant boundary conditions with the aim to keep conservation laws. This technique was used in [2]. The initial condition in the Riemann problem is replaced by the suitable one‐sided boundary condition. This results in the acceleration of the numerical method itself. On the inlet the pressure and the density and the angle of attack or velocity vector and the entropy are prescribed. On the outlet the pressure or normal component of the velocity or temperature or mass flow are investigated in such a way to obtain the unique solution of the modified Riemann problem. Various combinations of inlet and outlet boundary conditions are investigated. This results in the sufficiently precise approximation of real flow boundary conditions. Numerical examples illustrating the usefulness of the proposed approach for cascade flow are presented. Another numerical example is shown in [3]. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computation of static‐equivalent load sets for bone remodeling simulation
Authors: Lutz André , Nackenhorst Udo 
Published: August 2008

AbstractTheories and related computational techniques for the prediction of bone mass loss, for example caused by endoprosthetic treatment, have been under discussion for more than 20 years. Today, numerical aspects and constitutive modeling of stress adaptive bone remodeling seem to be sufficiently solved. However there is an open question about the description of the loading conditions in the framework of quasi‐static approaches (see e.g. [1]). Due to the complexity of the subject only a limited data base is available on measured and computed joint and muscle forces for typical movements. To close this gap, an inverse simulation approach on the identification of static‐equivalent load sets related to measured bone mass density distributions will be presented in this contribution. Based on a first order approach of bone remodeling, these load sets are computed by an hierarchic genetic‐gradient algorithm and lead to the original bone mass distribution obtained by high resolution imaging techniques. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The application of the FDEM program package with error estimate to industrial problems
Authors: Adolph Torsten , Schönauer Willi 
Published: August 2008

AbstractThe Finite Difference Element Method (FDEM) program package is a robust and efficient black‐box solver that solves arbitrary nonlinear systems of elliptic and parabolic partial differential equations under arbitrary nonlinear boundary conditions on arbitrary domains in 2‐D and 3‐D. FDEM is an unprecedented generalization of the finite difference method on unstructured finite element meshes. From the difference of formulas of different order, we get an easy access to the discretization error. By the knowledge of this error, the mesh may be refined locally to reduce the error to a prescribed relative tolerance. The error estimate is a unique property for such a general black‐box. In addition, the FDEMprogram package is efficiently parallelized on distributed memory parallel computers.In this paper we demonstrate the usefulness of the FDEM program package by its application to several industrial problems. This gives completely new results as up to now people have solved these problems blindly, unaware of the error of their solution. The first problem is the numerical simulation of a microreactor where we have one chemical component entering through the main channel and one chemical component entering through a side channel so that there is a reaction of the components. We want to examine the flow field and the behaviour of the chemical components. The second problem is the heat conduction in a high pressure Diesel injection pump. This problem is based on a preceding fluid‐structure interaction problem, and we now compute the temperature distribution in the injection pump additionally. Finally, we simulate the distribution of the temperature in a DC/AC converter module with six power‐MOSFETs heated with uniform power. At the bottom of the module air cooling is applied. In contrast to the first two elliptic problems, this is a 3‐D parabolic problem. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of skin‐stiffener debonding in stiffened carbon/epoxy panels
Authors: Balzani Claudio , Wagner Werner 
Published: August 2008

AbstractAircraft fuselage structures are typically composed of a curved skin connected to longitudinal stiffeners. They are nowadays made of carbon/epoxy laminates. Skin‐stiffener debonding can lead to a significant reduction of their compressive loadcarrying capacity in the postbuckling range of response. This work examines this effect in the framework of the finite element method. A zero‐thickness interface element written in terms of cohesive tractions and relative displacements is derived which is inserted between skin and stiffener. A special cohesive law already presented in [1, 2] describes the softening behavior of the interface while taking into account contact conditions. A numerical example shows the applicability of the model. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Empirical study of the rate of convergence of some fixed point iterative methods
Authors: Berinde Vasile , Păcurar Mădălina 
Published: August 2008

AbstractAn approach for the empirical study of the rate of convergence of fixed point iterative methods is presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Adaptive least‐squares finite element approximations to transonic‐flow problems
Authors: Chang Shin‐Perng , Chen Tsu‐Fen 
Published: August 2008

AbstractThis work concerns solutions of compressible potential flow problems based on weighted least‐squares finite element approximations. The model problem considered is that of the potential flow past a circular cylinder. To capture the transonic flow region, an adaptive algorithm based on mesh redistribution with local mesh refinement and smoothing is developed for suitably weighted least‐squares approximations. Numerical results for the model problem are given for the transonic case with shocks. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An adaptive level set method for shock‐driven fluid‐structure interaction
Authors: Deiterding Ralf 
Published: August 2008

AbstractThe fluid‐structure interaction simulation of shock‐ and detonation‐loaded structures requires numerical methods that can cope with large deformations as well as local topology changes. A robust, level‐set‐based shock‐capturing fluid solver is described that allows coupling to any solid mechanics solver. As computational example, the elastic response of a thin steel panel, modeled with both shell and beam theory, to a shock wave in air is considered. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Displacement field analysis of the topology optimized structure
Authors: Kutylowski Ryszard 
Published: August 2008

AbstractIn this paper for the topology optimization process the minimum compliance approach is used with FEM as very useful method for numerical realization of the problem. During the optimization process homogenized domain changes into discrete structure which means the final structure consists of the many optimal placed bars. The analysis of the deformed structure and the deformed finite elements is done from the displacement field point of view. It can be noticed, some of the finite elements reduce their size, some of them increase their size. It depends on the element status (void‐empty, stressed or not stressed). The question arises: is the topology optimization process cause of the negative Poisson ratio for some parts of the structure? (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of pharmacokinetic uncertainty generated by irregular drug intake: A stochastic modeling approach
Authors: Nekka Fahima , Gohore Bi Denis , Fenneteau Frédérique , Li Jun 
Published: August 2008

AbstractIn this paper, we have translated, in mathematical terms, a largely reported swine feeding behaviour and assessed its impact on pharmacokinetics of the chosen antibiotic. This mechanistic‐based approach allowed us to delineate the role of different feeding patterns, to quantify the pharmacokinetic variability induced by feeding behaviour and to learn about random features of the pharmacokinetic variation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A quadrature free convergent method for the numerical solution of linear Fredholm integral equations based on Hermite‐spline interpolation
Authors: Shahmorad S. , Abdollahi A. 
Published: August 2008

AbstractIn this paper we use the Hermite‐spline interpolation in a special form for the numerical solution of linear Fredholm integral equations. We prove the convergence of this method as a main part of the paper. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)