bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human CCR4+CCR6+Th17 Cells Suppress Autologous CD8+ T Cell Responses
Authors: Zhao Fei , Hoechst Bastian , Gamrekelashvili Jaba , Ormandy Lars A. , Voigtländer Torsten , Wedemeyer Heiner , Ylaya Kris , Wang Xin Wei , Hewitt Stephen M. , Manns Michael P. , Korangy Firouzeh , Greten Tim F. 
Published: May 2012

Abstract
The role of Th17 cells in cancer patients remains unclear and controversial. In this study, we have analyzed the phenotype of in vitro primed Th17 cells and further characterized their function on the basis of CCR4 and CCR6 expression. We show a novel function for a subset of IL-17–secreting CD4+ T cells, namely, CCR4+CCR6+Th17 cells. When cultured together, CCR4+CCR6+Th17 cells suppressed the lytic function, proliferation, and cytokine secretion of both Ag-specific and CD3/CD28/CD2-stimulated autologous CD8+ T cells. In contrast, CCR4−CCR6+ CD4+ T cells, which also secrete IL-17, did not affect the CD8+ T cells. Suppression of CD8+ T cells by CCR4+CCR6+Th17 cells was partially dependent on TGF-β, because neutralization of TGF-β in cocultures reversed their suppressor function. In addition, we also found an increase in the frequency of CCR4+CCR6+, but not CCR4−CCR6+ Th17 cells in peripheral blood of hepatocellular carcinoma patients. Our study not only underlies the importance of analysis of subsets within Th17 cells to understand their function, but also suggests Th17 cells as yet another immune evasion mechanism in hepatocellular carcinoma. This has important implications when studying the mechanisms of carcinogenesis, as well as designing effective immunotherapy protocols for patients with cancer.
Dendritic Cell-Specific Transcript: Dendritic Cell Marker and Regulator of TLR-Induced Cytokine Production
Authors: Hontelez Saartje , Ansems Marleen , Karthaus Nina , Zuidscherwoude Malou , Looman Maaike W. , Triantis Vassilis , Adema Gosse J. 
Published: May 2012

Abstract
Dendritic cells (DCs) are the professional APCs of the immune system that dictate the type and course of an immune response. Molecular understanding of DC biology is important for the design of DC-based immunotherapies and optimal clinical applications in vaccination settings. Previously, we isolated and characterized the cDNA-encoding dendritic cell-specific transcript (DC-SCRIPT; also known as ZNF366). DC-SCRIPT mRNA expression in the immune system was confined to DCs and was reported to be an early hallmark of DC differentiation. In this study, we demonstrate IL-4 to be the dominant factor for DC-SCRIPT expression in human monocyte-derived DCs. In addition, to our knowledge, we show for the first time endogenous DC-SCRIPT protein expression in human DCs both in vitro and in situ. DC-SCRIPT protein is detected early upon differentiation of monocytes into DCs and is also present in multiple freshly isolated DC subsets. Maturation of DCs with TLR ligands further increased DC-SCRIPT mRNA expression, suggesting a role in DC maturation. Indeed, small interfering RNA-mediated knockdown of DC-SCRIPT affected the cytokine response upon TLR stimulation. These DCs displayed enhanced IL-10 and decreased IL-12 production, compared with wild-type DCs. Silencing of IL-10 in DC-SCRIPT knockdown DCs rescued IL-12 expression, suggesting a primary role for DC-SCRIPT in the regulation of IL-10 production.
Glucocorticoids Relieve Collectin-Driven Suppression of Apoptotic Cell Uptake in Murine Alveolar Macrophages through Downregulation of SIRPα
Authors: McCubbrey Alexandra L. , Sonstein Joanne , Ames Theresa M. , Freeman Christine M. , Curtis Jeffrey L. 
Published: May 2012

Abstract
The lung environment actively inhibits apoptotic cell (AC) uptake by alveolar macrophages (AMøs) via lung collectin signaling through signal regulatory protein α (SIRPα). Even brief glucocorticoid (GC) treatment during maturation of human blood monocyte-derived or murine bone marrow-derived macrophages (Møs) increases their AC uptake. Whether GCs similarly impact differentiated tissue Møs and the mechanisms for this rapid response are unknown and important to define, given the widespread therapeutic use of inhaled GCs. We found that the GC fluticasone rapidly and dose-dependently increased AC uptake by murine AMøs without a requirement for protein synthesis. Fluticasone rapidly suppressed AMø expression of SIRPα mRNA and surface protein, and also activated a more delayed, translation-dependent upregulation of AC recognition receptors that was not required for the early increase in AC uptake. Consistent with a role for SIRPα suppression in rapid GC action, murine peritoneal Møs that had not been exposed to lung collectins showed delayed, but not rapid, increase in AC uptake. However, pretreatment of peritoneal Møs with the lung collectin surfactant protein D inhibited AC uptake, and fluticasone treatment rapidly reversed this inhibition. Thus, GCs act not only by upregulating AC recognition receptors during Mø maturation but also via a novel rapid downregulation of SIRPα expression by differentiated tissue Møs. Release of AMøs from inhibition of AC uptake by lung collectins may, in part, explain the beneficial role of inhaled GCs in inflammatory lung diseases, especially emphysema, in which there is both increased lung parenchymal cell apoptosis and defective AC uptake by AMøs.
Pseudostress-Based Mixed Finite Element Methods for the Stokes Problem in ℝnwith Dirichlet Boundary Conditions. I: A Priori Error Analysis
Authors: Gatica Gabriel N. , Márquez Antonio , Sánchez Manuel A. 
Published: May 2012

AbstractWe consider a non-standard mixed method for the Stokes problem in ℝn,nЄ {2,3}, with Dirichlet boundary conditions, in which, after using the incompressibility condition to eliminate the pressure, the pseudostress tensor σ and the velocity vectorubecome the only unknowns. Then, we apply the Babuška-Brezzi theory to prove the well-posedness of the corresponding continuous and discrete formulations. In particular, we show that Raviart-Thomas elements of orderk≥0 for σ and piecewise polynomials of degreekforuensure unique solvability and stability of the associated Galerkin scheme. In addition, we introduce and analyze an augmented approach for our pseudostress-velocity formulation. The methodology employed is based on the introduction of the Galerkin least-squares type terms arising from the constitutive and equilibrium equations, and the Dirichlet boundary condition for the velocity, all of them multiplied by suitable stabilization parameters. We show that these parameters can be chosen so that the resulting augmented variational formulation is defined by a strongly coercive bilinear form, whence the associated Galerkin scheme becomes well posed for any choice of finite element subspaces. For instance, Raviart-Thomas elements of orderk≥0 for σ and continuous piecewise polynomials of degreek+1 forubecome a feasible choice in this case. Finally, extensive numerical experiments illustrating the good performance of the methods and comparing them with other procedures available in the literature, are provided.
A Cluster Dynamics Model For Accumulation Of Helium In Tungsten Under Helium Ions And Neutron Irradiation
Authors: Li Y. G. , Zhou W. H. , Ning R. H. , Huang L. F. , Zeng Z. , Ju X. 
Published: May 2012

AbstractA cluster dynamics model based on rate theory has been developed to describe the accumulation and diffusion processes of helium in tungsten under helium implantation alone or synergistic irradiation with neutron, by involving different types of objects, adopting up-to-date parameters and complex reaction processes as well as considering the diffusion process along with depth. The calculated results under different conditions are in good agreement with experiments much well. The model describes the behavior of helium in tungsten within 2D space of defect type/size and depth on different ions incident conditions (energies and fluences) and material conditions (system temperature and existent sinks), by including the synergistic effect of helium-neutron irradiations and the influence of inherent sinks (dislocation lines and grain boundaries). The model, coded as IRadMat, would be universally applicable to the evolution of defects for ions/neutron irradiated on plasma-facing materials.
Elements of Mathematical Foundations for Numerical Approaches for Weakly Random Homogenization Problems
Authors: Anantharaman A. , Le Bris C. 
Published: May 2012

AbstractThis work is a follow-up to our previous work. It extends and complements, both theoretically and experimentally, the results presented there. Under consideration is the homogenization of a model of a weakly random heterogeneous material. The material consists of a reference periodic material randomly perturbed by another periodic material, so that its homogenized behavior is close to that of the reference material. We consider laws for the random perturbations more general than in. We prove the validity of an asymptotic expansion in a certain class of settings. We also extend the formal approach introduced in. Our perturbative approach shares common features with a defect-type theory of solid state physics. The computational efficiency of the approach is demonstrated.
Improvement on Spherical Symmetry in Two-Dimensional Cylindrical Coordinates for a Class of Control Volume Lagrangian Schemes
Authors: Cheng Juan , Shu Chi-Wang 
Published: May 2012

AbstractIn, Maire developed a class of cell-centered Lagrangian schemes for solving Euler equations of compressible gas dynamics in cylindrical coordinates. These schemes use a node-based discretization of the numerical fluxes. The control volume version has several distinguished properties, including the conservation of mass, momentum and total energy and compatibility with the geometric conservation law (GCL). However it also has a limitation in that it cannot preserve spherical symmetry for one-dimensional spherical flow. An alternative is also given to use the first order area-weighted approach which can ensure spherical symmetry, at the price of sacrificing conservation of momentum. In this paper, we apply the methodology proposed in our recent work to the first order control volume scheme of Maire in to obtain the spherical symmetry property. The modified scheme can preserve one-dimensional spherical symmetry in a two-dimensional cylindrical geometry when computed on an equal-angle-zoned initial grid, and meanwhile it maintains its original good properties such as conservation and GCL. Several two-dimensional numerical examples in cylindrical coordinates are presented to demonstrate the good performance of the scheme in terms of symmetry, non-oscillation and robustness properties.
A Unstructured Nodal Spectral-Element Method for the Navier-Stokes Equations
Authors: Chen Lizhen , Shen Jie , Xu Chuanju 
Published: May 2012

AbstractAn unstructured nodal spectral-element method for the Navier-Stokes equations is developed in this paper. The method is based on a triangular and tetrahedral rational approximation and an easy-to-implement nodal basis which fully enjoys the tensorial product property. It allows arbitrary triangular and tetrahedral mesh, affording greater flexibility in handling complex domains while maintaining all essential features of the usual spectral-element method. The details of the implementation and some numerical examples are provided to validate the efficiency and flexibility of the proposed method.
Numerical Simulation of a Three-Dimensional Fish-like Body Swimming with Finlets
Authors: Wang Shizhao , Zhang Xing , He Guowei 
Published: May 2012

AbstractThe swimming of a 3D fish-like body with finlets is numerically investigated at Re = 1000 (the Reynolds number is based on the uniform upstream flow and the length of the fish-like body). The finlets are simply modeled as thin rigid rectangular plates that undulate with the body. The wake structures and the flow around the caudal peduncle are studied. The finlets redirect the local flow across the caudal peduncle but the vortical structures in the wake are almost not affected by the finlets. Improvement of hydrodynamic performance has not been found in the simulation based on this simple model. The present numerical result is in agreement with that of the work of Nauen and Lauder [J. Exp. Biol., 204 (2001), pp. 2251-2263] and partially supports the hypothesis of Webb [Bull. Fish. Res. Bd. Can., 190 (1975), pp. 1-159].
Effects of Dzyaloshinsky-Moriya Interaction on Planar Rotator Model on Triangular Lattice
Authors: Sun Yun-Zhou , Yi Lin , Wang Jian-Sheng 
Published: May 2012

AbstractThe thermodynamic properties and some critical properties of the planar rotator model with chiral Dzyaloshinsky-Moriya (DM) interaction on triangular lattice are analyzed using a hybrid Monte Carlo method. It has been shown that there is a XY-like Berezinskii-Kosterlitz-Thouless (BKT) phase transition in this model. The ground state of this spiral system and the effects of size mismatch are also discussed.
Lattice Free Stochastic Dynamics
Authors: Sopasakis Alexandros 
Published: May 2012

AbstractWe introduce a lattice-free hard sphere exclusion stochastic process. The resulting stochastic rates are distance based instead of cell based. The corresponding Markov chain build for this many particle system is updated using an adaptation of the kinetic Monte Carlo method. It becomes quickly apparent that due to the lattice-free environment, and because of that alone, the dynamics behave differently than those in the lattice-based environment. This difference becomes increasingly larger with respect to particle densities/temperatures. The well-known packing problem and its solution (Palasti conjecture) seem to validate the resulting lattice-free dynamics.
Parareal in Time Simulation Of Morphological Transformation in Cubic Alloys with Spatially Dependent Composition
Authors: He Li-Ping , He Minxin 
Published: May 2012

AbstractIn this paper, a reduced morphological transformation model with spatially dependent composition and elastic modulus is considered. The parareal in time al-gorithm introduced by Lions et al. is developed for longer-time simulation. The fine solver is based on a second-order scheme in reciprocal space, and the coarse solver is based on a multi-model backward Euler scheme, which is fast and less expensive. Numerical simulations concerning the composition with a random noise and a discontinuous curve are performed. Some microstructure characteristics at very low temperature are obtained by a variable temperature technique.
Supersonic Flows with Nontraditional Transport Described by Kinetic Methods
Authors: Aristov V. V. , Frolova A. A. , Zabelok S. A. 
Published: May 2012

AbstractA new class of supersonic nonequilibrium flows is studied on the basis of solving the Boltzmann and model kinetic equations with the aim to consider new non-linear structures in open systems and to study anomalous transfer properties in relaxation zones. The Unified Flow Solver is applied for numerical simulations. Simple gases and gases with inner degrees of freedom are considered. The experimental data related to the influence of the so-called optical lattices on the supersonic molecular beams are considered and numerical analysis of the nonequilibrium states obtained on this basis is made. The nonuniform relaxation problem with these distributions is simulated numerically and anomalous transport is confirmed. The conditions for strong changes of the temperature in the anomalous transfer zones are discussed and are realized in computations.
Analysis And Efficient Solution Of Stationary Schrödinger Equation Governing Electronic States Of Quantum Dots And Rings In Magnetic Field
Authors: Betcke Marta M. , Voss Heinrich 
Published: May 2012

AbstractIn this work the one-band effective Hamiltonian governing the electronic states of a quantum dot/ring in a homogenous magnetic field is used to derive a pair/quadruple of nonlinear eigenvalue problems corresponding to different spin orientations and in case of rotational symmetry additionally to quantum number -L•i. We show, that each of those pair/quadruple of nonlinear problems allows for the min-max characterization of its eigenvalues under certain conditions, which are satisfied for our examples and the common InAs/GaAs heterojunction. Exploiting the minmax property we devise efficient iterative projection methods simultaneously handling the pair/quadruple of nonlinear problems and thereby saving up to 40% of the computational time as compared to the nonlinear Arnoldi method applied to each of the problems separately.
A Well-Posed and Discretely Stable Perfectly Matched Layer for Elastic Wave Equations in Second Order Formulation
Authors: Duru Kenneth , Kreiss Gunilla 
Published: May 2012

AbstractWe present a well-posed and discretely stable perfectly matched layer for the anisotropic (and isotropic) elastic wave equations without first re-writing the governing equations as a first order system. The new model is derived by the complex coordinate stretching technique. Using standard perturbation methods we show that complex frequency shift together with a chosen real scaling factor ensures the decay of eigen-modes for all relevant frequencies. To buttress the stability properties and the robustness of the proposed model, numerical experiments are presented for anisotropic elastic wave equations. The model is approximated with a stable node-centered finite difference scheme that is second order accurate both in time and space.
New Energy-Conserved Identitiesand Super-Convergence of the Symmetric Ec-S-Fdtd Scheme for Maxwell’s Equations in 2D
Authors: Gao Liping , Liang Dong 
Published: May 2012

AbstractThe symmetric energy-conserved splitting FDTD scheme developed in is a very new and efficient scheme for computing the Maxwell’s equations. It is based on splitting the whole Maxwell’s equations and matching the x-direction and y-direction electric fields associated to the magnetic field symmetrically. In this paper, we make further study on the scheme for the 2D Maxwell’s equations with the PEC boundary condition. Two new energy-conserved identities of the symmetric EC-S-FDTD scheme in the discrete H1-norm are derived. It is then proved that the scheme is uncondi-tionally stable in the discrete H1-norm. By the new energy-conserved identities, the super-convergence of the symmetric EC-S-FDTD scheme is further proved that it is of second order convergence in both time and space steps in the discrete H1-norm. Numerical experiments are carried out and confirm our theoretical results.
Adaptive Cloud Refinement (ACR) - Adaptation in Meshless Framework
Authors: Somasekhar M. , Vivek S. , Malagi Keshav. S. , Ramesh V. , Deshpande S. M. 
Published: May 2012

AbstractIn the present work adaptation in meshless framework is proposed. The grid adaptation or mesh adaptation is quite well developed area in case of conventional grid based solvers and is popularly known as Adaptive mesh refinement (AMR). In such cases the adaptation is done by subdividing the cells or elements into finer cells or elements. In case of meshless methods there are no cells or elements but only a cloud of points. In this work we propose to achieve the meshless adaptation by locally refining the point density in the regions demanding higher resolution. This results into an adaptive enriched cloud of points. We call this method as Adaptive Cloud Refinement (ACR). The meshless solvers need connectivity information, which is a set of neighboring nodes. It is crucial part of meshless solvers. Obviously because of refining point density, the connectivity of nodes in such regions gets modified and hence has to be updated. An efficient connectivity update must exploit the fact that the node distribution would be largely unaffected except the region of adaptation. Hence connectivity updating needs to be done locally, only in these regions. In this paper we also present an extremely fast algorithm to update connectivity over adapted cloud called as ACU (Automatic Connectivity Update).
A Novel Dynamic Quadrature Scheme for Solving Boltzmann Equation with Discrete Ordinate and Lattice Boltzmann Methods
Authors: Hsu C. T. , Chiang S. W. , Sin K. F. 
Published: May 2012

AbstractThe Boltzmann equation (BE) for gas flows is a time-dependent nonlinear differential-integral equation in 6 dimensions. The current simplified practice is to linearize the collision integral in BE by the BGK model using Maxwellian equilibrium distribution and to approximate the moment integrals by the discrete ordinate method (DOM) using a finite set of velocity quadrature points. Such simplification reduces the dimensions from 6 to 3, and leads to a set of linearized discrete BEs. The main difficulty of the currently used (conventional) numerical procedures occurs when the mean velocity and the variation of temperature are large that requires an extremely large number of quadrature points. In this paper, a novel dynamic scheme that requires only a small number of quadrature points is proposed. This is achieved by a velocity-coordinate transformation consisting of Galilean translation and thermal normalization so that the transformed velocity space is independent of mean velocity and temperature. This enables the efficient implementation of Gaussian-Hermite quadrature. The velocity quadrature points in the new velocity space are fixed while the correspondent quadrature points in the physical space change from time to time and from position to position. By this dynamic nature in the physical space, this new quadrature scheme is termed as the dynamic quadrature scheme (DQS). The DQS was implemented to the DOM and the lattice Boltzmann method (LBM). These new methods with DQS are therefore termed as the dynamic discrete ordinate method (DDOM) and the dynamic lattice Boltzmann method (DLBM), respectively. The new DDOM and DLBM have been tested and validated with several testing problems. Of the same accuracy in numerical results, the proposed schemes are much faster than the conventional schemes. Furthermore, the new DLBM have effectively removed the incompressible and isothermal restrictions encountered by the conventional LBM.
On Computational Modelling Of Strain-Hardening Material Dynamics
Authors: Barton Philip , Romenski Evgeniy 
Published: May 2012

AbstractIn this paper we show that entropy can be used within a functional for the stress relaxation time of solid materials to parametrise finite viscoplastic strain-hardening deformations. Through doing so the classical empirical recovery of a suitable irreversible scalar measure of work-hardening from the three-dimensional state parameters is avoided. The success of the proposed approach centres on determination of a rate-independent relation between plastic strain and entropy, which is found to be suitably simplistic such to not add any significant complexity to the final model. The result is sufficiently general to be used in combination with existing constitutive models for inelastic deformations parametrised by one-dimensional plastic strain provided the constitutive models are thermodynamically consistent. Here a model for the tangential stress relaxation time based upon established dislocation mechanics theory is calibrated for OFHC copper and subsequently integrated within a two-dimensional moving-mesh scheme. We address some of the numerical challenges that are faced in order to ensure successful implementation of the proposedmodel within a hydrocode. The approach is demonstrated through simulations of flyer-plate and cylinder impacts.