bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional and Morphological Comparison of Three Primary Liver Cell Types Cultured in the AMC Bioartificial Liver
Authors: Poyck Paul P.C. , Hoekstra Ruurdtje , van Wijk Albert C.W.A. , Attanasio Chiara , Calise Fulvio , Chamuleau Robert A.F.M. , van Gulik Thomas M. 
Published: March 2007

Abstract
The selection of a cell type for bioartificial liver (BAL) systems for the treatment of patients with acute liver failure is in part determined by issues concerning patient safety and cell availability. Consequently, mature porcine hepatocytes (MPHs) have been widely applied in BAL systems. The success of clinical BAL application systems is, however, largely dependent on the functionality and stability of hepatocytes. Therefore, we compared herein the general metabolic and functional activities of MPHs with mature human hepatocytes (MHHs) in the Academic Medical Center (AMC)-BAL during a 7-day culture period. We also tested fetal human hepatocytes (FHHs), since their proliferation capacity is higher than MHHs and their function is increased compared to human liver cell lines. The results showed large differences between the 3 cell types. MHHs eliminated 2-fold more ammonia and produced 3-fold more urea than MPHs, whereas FHHs produced ammonia. Lidocaine elimination of FHHs was 3.5-fold higher than MPHs and 6.6-fold higher than of MHHs. Albumin production was not different between the 3 cell types. MPHs and FHHs became increasingly glycolytic, whereas MHHs remained metabolically stable during the whole culture period. MHHs and MPHs formed tissue-like structures inside the AMC-BAL. In conclusion, we propose that FHHs can be considered as a suitable cell type for pharmacological studies inside a bioreactor. However, we conclude that MHHs are the preferred cell source for loading a BAL device for clinical use, because of their high ammonia eliminating capacity and metabolic stability. MPHs should be considered as the best alternative cell source for BAL application, although their phenotypic instability urges application within 1 or 2 days after loading. Liver Transpl 13:589–598, 2007. © 2007 AASLD.
B-Cell Surface Marker Analysis for Improvement of Rituximab Prophylaxis in ABO-Incompatible Adult Living Donor Liver Transplantation
Authors: Egawa Hiroto , Ohmori Katsuyuki , Haga Hironori , Tsuji Hiroaki , Yurugi Kimiko , Miyagawa-Hayashino Aya , Oike Fumitaka , Fukuda Akinari , Yoshizawa Jun , Takada Yasutsugu , Tanaka Koichi , Maekawa Taira , Ozawa Kazue , Uemoto Shinji 
Published: March 2007

Abstract
Although the effectiveness of rituximab has been reported in ABO blood group (ABO)-incompatible (ABO-I) organ transplantation, the protocol is not yet established. We studied the impact of the timing of rituximab prophylaxis and the humoral immune response of patients undergoing ABO-I living donor liver transplantation (LDLT), focusing on clinicopathological findings and the B-cell subset. From July 2003 to December 2005, 30 adult patients were treated with hepatic artery infusion (HAI) protocol without splenectomy for ABO-I LDLT. A total of 17 patients were treated only with HAI (no prophylaxis), and the other 13 were treated with rituximab prophylaxis at various times prior to transplantation. For B-cell study of the spleen, another 4 patients undergoing ABO-I LDLT both with HAI after prophylaxis and eventual splenectomy, and 3 patients with ABO-compatible LDLT with splenectomy were enrolled. The mortality of the 30 patients with HAI, without splenectomy, and with/without rituximab prophylaxis was 33% and the main cause of death was sepsis. Peripheral blood B cells were completely depleted, anti-donor blood-type antibody titer was lower, and clinical and pathological antibody-mediated rejection was not observed in patients with prophylaxis earlier than 7 days before transplantation (early prophylaxis). Early rituximab prophylaxis significantly depleted B cells and memory B cells in the spleen but not in lymph nodes. On the other hand, B cells and memory B cells increased and memory B cells became dominant during antibody-mediated rejection. In conclusion, early prophylaxis with rituximab depletes B cells, including memory B cells, in the spleen and is associated with a trend toward lower humoral rejection rates and lower peak immunoglobulin (Ig)G titers in ABO-I LDLT patients. Liver Transpl 13:579–588, 2007. © 2007 AASLD.
Developmental exposure to diethylstilbestrol alters uterine gene expression that may be associated with uterine neoplasia later in life
Authors: Newbold Retha R. , Jefferson Wendy N. , Grissom Sherry F. , Padilla‐Banks Elizabeth , Snyder Ryan J. , Lobenhofer Edward K. 
Published: March 2007

AbstractPreviously, we described a mouse model where the well‐known reproductive carcinogen with estrogenic activity, diethylstilbestrol (DES), caused uterine adenocarcinoma following neonatal treatment. Tumor incidence was dose‐dependent reaching >90% by 18 mo following neonatal treatment with 1000 µg/kg/d of DES. These tumors followed the initiation/promotion model of hormonal carcinogenesis with developmental exposure as initiator, and exposure to ovarian hormones at puberty as the promoter. To identify molecular pathways involved in DES‐initiation events, uterine gene expression profiles were examined in prepubertal mice exposed to DES (1, 10, or 1000 µg/kg/d) on days 1–5 and compared to controls. Of more than 20 000 transcripts, approximately 3% were differentially expressed in at least one DES treatment group compared to controls; some transcripts demonstrated dose–responsiveness. Assessment of gene ontology annotation revealed alterations in genes associated with cell growth, differentiation, and adhesion. When expression profiles were compared to published studies of uteri from 5‐d‐old DES‐treated mice, or adult mice treated with 17β estradiol, similarities were seen suggesting persistent differential expression of estrogen responsive genes following developmental DES exposure. Moreover, several altered genes were identified in human uterine adenocarcinomas. Four altered genes [lactotransferrin (Ltf), transforming growth factor beta inducible (Tgfb1), cyclin D1 (Ccnd1), and secreted frizzled‐related protein 4 (Sfrp4)], selected for real‐time RT‐PCR analysis, correlated well with the directionality of the microarray data. These data suggested altered gene expression profiles observed 2 wk after treatment ceased, were established at the time of developmental exposure and maybe related to the initiation events resulting in carcinogenesis. © 2007 Wiley‐Liss, Inc.
Striatal gray matter loss in Huntington's disease is leftward biased
Authors: Mühlau Mark , Gaser Christian , Wohlschläger Afra M. , Weindl Adolf , Städtler Michael , Valet Michael , Zimmer Claus , Kassubek Jan , Peinemann Alexander 
Published: March 2007

AbstractIn Huntington's disease (HD), the distribution of pathological changes throughout the brain is incompletely understood. Some studies have identified leftward‐biased lateralization, whereas others did not. We performed magnetic resonance imaging and a voxel‐based asymmetry analysis in 44 right‐handed HD gene carriers (presymptomatic, n = 5; stage I, n = 28; stage II, n = 11) and 44 right‐handed healthy controls. The group comparison revealed leftward‐biased gray matter loss in the striatum. Further analyses showed no indication of asymmetry in presymptomatic HD patients but an increase in asymmetry in the course of the HD stages under examination. Our study demonstrates and discusses leftward‐biased gray matter loss in HD. © 2007 Movement Disorder Society
Ein algebraisches Verfahren zur Lösung von gemischten Anfangsrandwertproblemen aus der Theorie instationärer Gitterströmungen
Authors: Meister E. , Sommer H. J. 
Published: March 2007

AbstractMixed boundary value problems for the wave‐equation in the x‐y‐plane, with boundaries parallel to the x‐axis, are usually treated by Laplacetransformation. To use this method numerically we present it here by means of the Mikusiński‐calculus. In this paper our main interest lies in the treatment of mixed initial‐boundary value problems arising in unsteady subsonic cascade flow.
Global existence for two‐velocity models of the Boltzmann equation
Authors: Illner R. , Neunzert H. 
Published: March 2007

AbstractIf A is a symmetric 2 × 2‐matrix,

equation image

then the initial value problem

equation image

describes the evolution in time of a fictive gas whose particles can move only with the velocities u1 and v2. It is proved that, for continuous initial values vanishing at infinity, (1) has a global solution if an H‐Theorem holds for the gas described by (1). The validity of an H‐Theorem is expressed by the properties of A.
Hopf‐Bifurkation bei Lasern
Authors: Renardy M. , Kirchgässner K. 
Published: March 2007

AbstractThe semiclassical equations describing a ring laser show two successive bifurcations, one stationary and one Hopf bifurcation. This phenomenon is analyzed mathematically. The initial value problem for the laser equations and the stability of the stationary solutions are discussed in detail. The transition to ultrashort laser pulses is shown to be a Hopf bifurcation. The direction of the bifurcation is determined for a numerical example. It turns out that it depends on the parameters of the system.
On the integral equation method for the plane mixed boundary value problem of the Laplacian
Authors: Wendland W. L. , Stephan E. , Hsiao G. C. , Meister E. 
Published: March 2007

AbstractAlthough the plane boundary value problem for the Laplacian with given Dirichlet data on one part Γ2and given Neumann data on the remaining part Γ2of the boundary is the simplest case of mixed boundary value problems, we present several applications in classical mathematical physics. Using Green's formula the problem is converted into a system of Fredholm integral equations for the yet unknown values of the solutionuon Γ2and the also desired values of the normal derivatie on Γ1. One of these equations has principal part of the second kind, whereas that one of the other is of the first kind. Since any improvement of constructive methods requires higher regularity ofubut, on the other hand, gradupossesses singularities at the collision points Γ1∩ Γ2even forC∞data,uis decomposed into special singular terms and a regular rest. This is incorporated into the integral equations and the modified system is solved in appropriate Sobolev spaces. The solution of the system requires to solve a Fredholm equation of the first kind on the arc Γ2providing an improvement of regularity for the smooth part ofu. Since the integral equations form a strongly elliptic system of pseudodifferential operators, the Galerkin procedure converges. Using regular finite element functions on Γ1and Γ2augmented by the special singular functions we obtain optimal order of asymptotic convergence in the norm corresponding to the energy norm ofuand also superconvergence as well as high orders in smoother norms if the given data are smooth (and not the solution).
On boundary controllability of one‐dimensional vibrating systems
Authors: Krabs W. , Meister E. 
Published: March 2007

AbstractIn this paper boundary controllability of one‐dimensional vibrating system such as the vibrating string or the vibrating beam is studied. In particular we are concerned with the question whether it is possible to transfer a given initial state of vibration into rest within a given time such that the system stays in rest when the control is turned off.This problem is rephrased as a typical trigonometric moment problem which is solved within the framework of an abstract moment problem in a Hilbert space. The results of null‐controllability which are obtained are substantially based on classical results of Ingham and Redheffer concerning trigonometric inequalities and incompleteness of certain sequences of trigonometric functions, respectively. The representation of the general statements follows closely the lines of a paper of Russell. Besides a special case is treated where explicit representations of boundary controls can be given that transfer the system to a permanent rest position. This special case includes amplitude boundary control of the vibrating string and the freely supported beam.
Stationary solutions of reaction‐diffusion equations
Authors: Hadeler K. P. , Rothe F. , Vogt H. 
Published: March 2007

AbstractGiven a semilinear reaction‐diffusion equation. If the corresponding ordinary differential equation admits a convex compact positively invariant set and the boundary data assume their values in this set then the first and third boundary value problem have stationary solutions. The proofs are based on Weinberger's strong invariance principle, some related tools and the Leray‐Schauder degree. The theorem is applied to several equations from theoretical biology, also in the case of distinct diffusion rates.
On a class of elliptic singular perturbations with applications in population genetics
Authors: Grasman J. , Eckhaus W. 
Published: March 2007

AbstractWith the maximum principle for differential equations asymptotic estimates are made for a class of linear elliptic singular perturbation problems with resonant turning point behaviour in some of the independent variables. The method is applied to the stationary solution of the Kolmogorov backward equation in population genetics.
The Crocco transformation for the three‐dimensional Prandtl boundary layer equations
Authors: Nickel K. , Kirchgässner K. 
Published: March 2007

AbstractThe three‐dimensional fluid flow of a steady or unsteady moving incompressible continuous medium is considered. Several Crocco‐type transformations are applied which reduce the system of three equations of the Prandtl boundary layer to a system of two strongly coupled parabolic equations.
Newton iterations without inverting the Derivative
Authors: Scheurle J. , Kirchgässner K. 
Published: March 2007

AbstractWe describe an iteration procedure in a Banach space which is quadratically convergent like Newton's method. In fact, it is a modification of the latter. The inverted derivatives are replaced by so‐called contractors which are constructed recursively. Moreover, this method is extended to a scale of Banach spaces. It turns out that the rate of convergence remains quadratic, even if the norms of the contractors are increasing exponentially. A hard implicit function theorem results. In particular, this theorem can be applied to prove existence of quasiperiodic solutions for the Lorenz model of stationary convection.
A local compactness theorem for Maxwell's equations
Authors: Weber Ch. , Werner P. 
Published: March 2007

AbstractThe paper gives a proof, valid for a large class of bounded domains, of the following compactness statements: Let G be a bounded domain, β be a tensor‐valued function on G satisfying certain restrictions, and let {n} be a sequence of vector‐valued functions on G where the L2‐norms of {n}, {curl n}, and {div(β n)} are bounded, and where all n either satisfy x n = 0 or (β Fn) = 0 at the boundary ∂G of G ( = normal to ∂G): then {n} has a L2‐convergent subsequence. The first boundary condition is satisfied by electric fields, the second one by magnetic fields at a perfectly conducting boundary ∂G if β is interpreted as electric dielectricity ϵ or as magnetic permeability μ, respectively.These compactness statements are essential for the application of abstract scattering theory to the boundary value problem for Maxwell's equations.
Gradient bounds for plasma confinement
Authors: Stakgold I. , Hsiao G. C. 
Published: March 2007

AbstractThe problem of plasma confinement in a Tokomak machine has recently attracted considerable mathematical attention. In the present article, gradient bounds for the solution are obtained through the use of differential inequalities and the Hopf maximum principle. These estimates, which take slightly different forms in the plasma and vacuum regions, become exact in the one‐dimensional case. An estimate is also given for the distance from the boundary of the interior point where the maximum of the solution is attained.
Differentiable dependence upon the data in a one‐phase Stefan problem
Authors: Jochum P. , Brosowski B. 
Published: March 2007

AbstractIt is well known that the free boundary of the one‐phase Stefan problem (1.1–5) depends continuously on the boundary data [1]. In this paper we prove that, in addition, the solution operator S which, to each g. assigns the corresponding free boundary, is continuously Frechet differentiable and we give the defining formulas of the Frechet derivative.
Über die Radon‐Transformation kreissymmetrischer Funktionen und ihre Beziehung zur Sommerfeldschen Theorie der Hankelfunktionen
Authors: Müller C. , Richberg R. , Leis R. 
Published: March 2007

AbstractFor the Radon transform of functions with circular symmetry an inversion formula is proved in a new and elementary way. The inversion formula combined with Fourier theory is applied to Sommer‐feld's integral for H, yielding a representation of products which generalizes Nicholson's integral for |H| 2.
Numerical solution of Hopf bifurcation problems
Authors: Weber H. , Törnig W. 
Published: March 2007

AbstractWe present two numerical methods for the solution of Hopf bifurcation problems involving ordinary differential equations. The first one consists in a discretization of the continuous problem by means of shooting or multiple shooting methods. Thus a finite‐dimensional bifurcation problem of special structure is obtained. It may be treated by appropriate iterative algorithms. The second approach transforms the Hopf bifurcation problem into a regular nonlinear boundary value problem of higher dimension which depends on a perturbation parameter ϵ. It has isolated solutions in the ϵ‐domain of interest, so that conventional discretization methods can be applied. We also consider a concrete Hopf bifurcation problem, a biological feedback inhibition control system. Both methods are applied to it successfully.
Zur L∞‐Konvergenz finiter Elemente bei parabolischen Differentialgleichungen
Authors: Dobrowolski M. , Leis R. 
Published: March 2007

AbstractFor a parabolic model problem it is shown that the convergence rate of higher order finite element approximation is quasioptimal in L∞. Moreover, the estimate does not depend on the interval [0, T]. The essential tool of the proof is a modified weighted norm technique.
Eigenvalue bounds for Hill's equation
Authors: Lortz D. , Rebhan E. , Törnig W. 
Published: March 2007

AbstractFor Hill's equation

equation image

the lowest eigenvalue a0 of the boundary value problem y(x + 1) = y(x) is considered. Introducing Lp norms of the function f(x), lower bounds for a0 which depend only on this norm are derived for p = 1,2 and ∞ by solving a variational principle. For these lower bounds analytical expressions are obtained. The quality of the approximations thus obtained is discussed for Mathieu's equation and an application in magnetohydrodynamics is considered.
Galerkin's method and stability
Authors: Jones D. S. 
Published: March 2007

AbstractApproximation in least squares by Galerkin's method leads to a consideration of strongly minimal systems. Theorems are derived which permit the recognition of systems which are not strongly minimal from the characteristics of the elements themselves. Normalised systems cannot be strongly minimal without their eigenvalues being bounded above.Speared systems, which have desirable properties, are introduced and their main features determined. Convergence earmarks and error bounds are exposed.A new definition of stability, which is self‐checking in a computation, is suggested and its attributes delineated.The extension of the theory to equations involving positive‐definite operators is mentioned.
Ein Existenzsatz für die Vlasov‐Gleichung mit selbstkonsistentem Magnetfeld
Authors: Neunzert H. , Petry K. H. 
Published: March 2007

AbstractThe Vlasov equation with electric and magnetic fields generated by the distribution of the plasma is considered. For a simplified model with one space and two velocity coordinates and a mollification of the spatial density and the mean velocity in the Maxwell equations an existence and uniqueness theorem is proved.
Monoton einschließend konvergente iterationsprozesse vom gauß‐seidel‐typ zur lösung nichtlinearer gleichungssysteme im RN und anwendungen
Authors: Törnig W. 
Published: March 2007

AbstractIn this paper we describe a class of Gauß‐Seidel iterations for the solution of large sparse nonlinear systems of equations. For suitable starting vectors every method of this class is monotonically convergent with respect to both sides. The result will be applied to the numerical solution of nonlinear boundary‐value problems and boundary layer problems.
High Hartmann number flow through a rectangular duct with unequally and finitely conducting walls
Authors: Chee‐Seng Lim , Eckhaus W. 
Published: March 2007

AbstractNonsymmetric Hartmann flow through a rectangular duct is investigated for thin duct walls with, generally, unequal but finite conductivities. A high Hartmann number is adopted. Consistent with known phenomena, both Hartmann layers transverse to the applied magnetic field are assumed to be separated from the two side boundary layers by four corner regions plus four inner corner regions. The method of singular perturbations and matched asymptotic expansions is applied to the coupled system. The equations governing the core and Hartmann layers are first partially resolved for leading terms. This is then followed by tackling equations governing one side layer and two adjacent corner regions. The latters' incorporation secures, for the former, only those boundary conditions that are compatible along the transverse walls. Both corner regions are denied access to non‐required boundary conditions along the neighbouring side wall by the adjoining inner corner regions. However, the latters' boundary value problems need not be tackled for the acquirement of only dominant terms beyond all four inner corner regions. The complementary side layer and associated corners are accounted for by a non‐symmetric reflection principle.Results reveal that a difference between conductivities in the transverse walls together with at least one finitely conducting side wall impart to disturbances within the core and Hartmann layers (i) a nontrivial dependence on the transverse coordinate relative to the magnetic field and flow in addition to the (usual) dependence on the field aligned coordinate,
(ii) a dependence on side wall parameters in addition to the dependence on transverse wall parameters.Applications to related situations are considered. These include the case for a perfectly conducting lower wall, a finitely conducting upper wall, and equally and finitely conducting side walls.
Efficient implementation of ‘Optimal’ algorithms in computerized tomography
Authors: Natterer F. , Hadeler K. P. 
Published: March 2007

AbstractWe describe three optimal algorithms for the reconstruction of a function in R2 from a finite number of line or strip integrals: Optimal recovery, Bayes estimate, Tikhonov‐Phillips method. In the case of a rotationally invariant scanning geometry we show that the resulting linear system is a block‐cyclic convolution. This observation leads to algorithms which are roughly as efficient as filtered backprojection which is one of the standard methods. The algorithms can be applied to the case of hollow and truncated projections. Numerical examples are given.