bluuebunny/crossref_metadata_2025_split huggingface dataset:
3D and 4D sonographic imaging of amniotic band syndrome in early pregnancy
Authors: Inubashiri Eisuke , Hanaoka Uiko , Kanenishi Kenji , Yamashiro Chizu , Tanaka Hirokazu , Yanagihara Toshihiro , Hata Toshiyuki 
Published: September 2008

AbstractWe present a case of amniotic band syndrome diagnosed with two‐dimensional (2D), three‐dimensional (3D), and four‐dimensional (4D) sonography at 14 weeks and 5 days of gestation. Conventional 2D sonography revealed multiple amniotic bands, fetal acrania, deformed hand, gastroschisis, kyphoscoliosis, and club foot. 3D and 4D sonography revealed multiple amniotic bands swinging in the amniotic cavity with 1 of them attached to the fetal head, and the severe deformity of the fetal face. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Effects of cell‐penetrating peptides and pegylation on transfection efficiency of polyethylenimine in mouse lungs
Authors: Nguyen Juliane , Xie Xiulan , Neu Michael , Dumitrascu Rio , Reul Regina , Sitterberg Johannes , Bakowsky Udo , Schermuly Ralph , Fink Ludger , Schmehl Thomas , Gessler Tobias , Seeger Werner , Kissel Thomas 
Published: September 2008

AbstractBackgroundCell‐penetrating peptides (CPPs) could potentially be used as vectors for intracellular delivery of proteins, peptides and nucleic acids. The present study examined different CPPs, such as TAT‐derived and arginine rich sequences, as well as model amphiphilic peptide, with respect to transfection efficiency of pegylated polyethylenimine (PEI) in A549, Calu‐3 cells and in mice after intra‐tracheal administration.MethodsThe conjugates were prepared by the coupling of CPPs to PEI via a heterobifunctional polyethylene glycol (PEG) linker, resulting in the bioconjugates CPP‐PEG‐PEI. Structures were successfully confirmed by 1H‐nuclear magnetic resonance and diffusion‐ordered spectroscopy. Unmodified PEI 25 kDa was compared with pegylated PEI, and aggregation tendency in cell culture medium, interaction with mucin and stability against heparin was assayed. After evaluating transfection efficiency of the polymers in two different lung cell lines, luciferase reporter gene expression was determined in mouse lungs.ResultsAll conjugates showed superior transfection efficiency compared to unmodified PEI 25 kDa. The conjugates sizes were generally < 300 nm, thus enabling them to penetrate through the mucus lining of the lung and reach the target cells. Coupling of CPPs to PEG‐PEI, however, did not significantly improve transfection efficiency in A549 cells, calu‐3 cells and in mouse lungs.ConclusionsWe show that small and stable polyplex size achieved by pegylation is favourable for successful pulmonary gene delivery. Compared to PEI 25 kDa, pegylated PEI and CPP‐PEG‐PEI displayed enhanced transfection efficiency both in vitro and in vivo. Copyright © 2008 John Wiley & Sons, Ltd.
Management of spatial and temporal thermal dynamics using TLM
Authors: Koay A. L. , Wilkinson A. J. , Pulko S. H. 
Published: September 2008

AbstractThe design of a preliminary spatial thermal control algorithm is described. This is based on the traditional state‐space servo design and exploits the analogy between the transmission line matrix (TLM) method and state‐space. The TLM algorithm involves not only temporal dynamics but also spatial ones. The control algorithm presented here involves estimating an analogous TLM model for the process to be controlled, the states of which are then used to calculate the control signals, across space, to be employed.The performance of the control algorithm is briefly investigated over a range of design parameter values, in order to seek a preliminary insight into parameter selection. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of supplementation of garlic powder on rumen ecology and digestibility of nutrients in ruminants
Authors: Wanapat Metha , Khejornsart Pichad , Pakdee Pawadee , Wanapat Sadudee 
Published: September 2008

AbstractBACKGROUND: The present study investigated the effect of garlic powder (GAP) supplementation on rumen fermentation pattern, nutrient digestibility and intake in ruminants fed on straw as a roughage source.RESULTS: Dry matter intake and apparent digestibility of nutrients were similar among treatments. The apparent digestibility of crude protein tended to be higher in cattle supplemented with GAP compared to those fed without GAP (P = 0.08). Ruminal populations of protozoa and bacteria were decreased, as influenced by GAP supplementation. Ruminal pH and NH3‐N were similar among treatments, while blood urea nitrogen tended to be decreased (P < 0.05). Total volatile fatty acids (VFAs) were not affected by GAP supplementation but individual VFAs were significantly different (P < 0.05), especially C3; meanwhile, C2:C3 ratio was reduced by GAP supplementation (P < 0.05). In addition, N balances were significantly increased as level of GAP supplementation increased and was highest at 120 g d−1 GAP.CONCLUSION: Results of this study suggest that feeding of GAP at 80 g d−1 with urea‐treated rice straw could enhance ruminal propionate production and thus lower C2:C3 ratio, decreasing the protozoal population, as well as increasing N retention and absorption in ruminants. Copyright © 2008 Society of Chemical Industry
The protective effects of garlic oil on acute ethanol‐induced oxidative stress in the liver of mice
Authors: Zeng Tao , Zhang Cui‐Li , Pan Guang‐Bing , Zhao Sheng , Dou Dan‐Dan , Xin Xing , Xie Ke‐Qin 
Published: September 2008

AbstractBACKGROUND: Alcoholic liver disease is so serious that no effective therapies have been developed up to now. This study was conducted to elucidate the effects of garlic oil (GO) on acute ethanol‐induced liver injury. Male Kun‐Ming mice were orally administered GO (50, 100 or 200 mg kg−1) for 30 days and then ethanol (4.8 g kg−1). At 16 h after ethanol treatment the mice were sacrificed. Subsequent serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and triglyceride (TG) levels, hepatic malondialdehyde (MDA) and glutathione (GSH) levels and antioxidant enzyme activities were measured. Histopathological examination of mouse liver sections was performed by Sudan III staining.RESULTS: GO pretreatment significantly inhibited acute ethanol‐induced increase in ALT, AST, TG and MDA and decrease in GSH in a dose‐dependent manner. In the three GO groups the level of GSH increased by 10.3%, 15.8% (P < 0.05) and 25.5% (P < 0.01) respectively compared with that in the ethanol group. The activities of superoxide dismutase, catalase and glutathione reductase were increased markedly in the 200 mg kg−1 GO group (P < 0.01). Histopathological examination showed fewer fat droplets in liver sections of GO‐pretreated mice.CONCLUSION: GO may have protective effects against acute ethanol‐induced liver injury through restoration of the GSH level and enhancement of the activities of antioxidant enzymes. Copyright © 2008 Society of Chemical Industry
Determination of the content of fatty acid methyl esters (FAME) in biodiesel samples obtained by esterification using 1H‐NMR spectroscopy
Authors: Mello Vinicius M. , Oliveira Flavia C. C. , Fraga William G. , do Nascimento Claudia J. , Suarez Paulo A. Z. 
Published: September 2008

AbstractThree different calibration curves based on 1H‐NMR spectroscopy (300 MHz) were used for quantifying the reaction yield during biodiesel synthesis by esterification of fatty acids mixtures and methanol. For this purpose, the integrated intensities of the hydrogens of the ester methoxy group (3.67 ppm) were correlated with the areas related to the various protons of the alkyl chain (olefinic hydrogens: 5.30–5.46 ppm; aliphatic: 2.67–2.78 ppm, 2.30 ppm, 1.96–2.12 ppm, 1.56–1.68 ppm, 1.22–1.42 ppm, 0.98 ppm, and 0.84–0.92 ppm). The first curve was obtained using the peaks relating the olefinic hydrogens, a second with the parafinic protons and the third curve using the integrated intensities of all the hydrogens. A total of 35 samples were examined: 25 samples to build the three different calibration curves and ten samples to serve as external validation samples. The results showed no statistical differences among the three methods, and all presented prediction errors less than 2.45% with a co‐efficient of variation (CV) of 4.66%. Copyright © 2008 John Wiley & Sons, Ltd.
Monitoring dynamic alterations in calcium homeostasis by T1‐weighted and T1‐mapping cardiac manganese‐enhanced MRI in a murine myocardial infarction model
Authors: Waghorn Ben , Edwards Tiffany , Yang Yuhui , Chuang Kai‐Hsiang , Yanasak Nathan , Hu Tom C.‐C. 
Published: September 2008

AbstractManganese has been used as a T1‐weighted MRI contrast agent in a variety of applications. Because manganese ions (Mn2+) enter viable myocardial cells via voltage‐gated Ca2+ channels, manganese‐enhanced MRI is sensitive to the viability and inotropic state of the heart. In spite of the established importance of Ca2+ regulation in the heart both before and after myocardial injury, monitoring strategies to assess Ca2+ homeostasis in affected cardiac tissues are limited. This study implements a T1‐mapping method to obtain quantitative information both dynamically and over a range of MnCl2 infusion doses. To optimize the current Mn2+ infusion protocols, we performed both dose‐dependent and temporal washout studies. A non‐linear relationship between infused MnCl2 solution dose and increase in left ventricular wall relaxation rate (ΔR1) was observed. Control mice also exhibited significant Mn2+ clearance over time, with a decrease in ΔR1 of ∼50% occurring in just 2.5 h. The complicated efflux time dependence possibly suggests multiple efflux mechanisms. With the use of the measured relationship between infused Mn2+ dose, ΔR1, and inductively coupled plasma mass spectrometry data analysis provided a means of estimating the absolute heart Mn concentration in vivo. We show that this technique has the sensitivity to observe or monitor potential alterations in Ca2+ handling in vivo because of the physiological remodeling after myocardial infarction. Left ventricular free wall ΔR1 values were significantly lower (P = 0.005) in the adjacent zone, surrounding the injured myocardial tissue, than in healthy tissue. This inferred reduction in Mn concentration can be used to estimate potentially salvageable myocardium in vivo for future treatment or evaluation of disease progression. Copyright © 2008 John Wiley & Sons, Ltd.
Analysis of a thermomechanical phase transition model
Authors: Chełmiński Krzysztof , Hömberg Dietmar , Kern Daniela 
Published: September 2008

AbstractSubject of this work is a macroscopic thermomechanical model of phase transitions in steel. Effects like transformation strain and transformation plasticity induced by the phase transitions are considered and used to formulate a consistent thermomechanical model. The resulting system of state equations consists of a quasistatic momentum balance coupled with a nonlinear stress‐strain relation, a nonlinear energy balance equation and a system of ODEs for the phase volume fractions. We prove the existence of a unique weak solution using fixed‐point arguments. A key issue is a regularity analysis for the mechanical subsystem to obtain continuity of the stress tensor. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Simulation of the non‐isothermal flow in a twin‐screw extruder
Authors: Conzen Carsten , Wünsch Olaf 
Published: September 2008

AbstractThe paper deals with the numerical simulation and experimental validation of transport phenomena in a co‐rotating twin screw extruder. We show steady state simulations of conveying elements in a relative system and compare them with transient simulations. With the transient simulation we are able to simulate the temperature development in the twin screw extruder. The results are compared with experimental results and show good agreement. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nondegeneracy, from the prospect of wave‐wave regular interactions of a gasdynamic type
Authors: Dinu Liviu Florin , Dinu Marina Ileana 
Published: September 2008

AbstractA parallel is considered between Burnat's “algebraic” approach [restricted to a genuine nonlinearity] and Martin's “differential” approach regarding their contribution to describing some nondegenerate one‐dimensional gasdynamic regular interaction solutions. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase‐field modeling and simulations of multicomponent cell membranes
Authors: Du Qiang 
Published: September 2008

AbstractIn this talk, we report some of recent works with current and former colleagues at Penn State (S. Das, M. Li, C. Liu, R. Ryham, X. Wang and J. Zhang) on the phase field modeling and simulations of the vesicle membrane deformation under elastic bending energy and the interaction with background fluid flows and other external fields. We discuss the relations between the phase field model and the sharp interface limits and numerical simulations of membranes with various topology and multiple components. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling of latent energy storage effects in thermoplasticity of metals
Authors: Fritzen Felix , Böhlke Thomas , Schnack Eckart 
Published: September 2008

AbstractThe modeling of coupled thermo‐plasticity includes the consideration of self‐heating which produces significant effects in many metal‐forming applications. While it has become given practice to use a constant fraction of the plastic power as heat production term in computations, experiments show considerably varying Taylor‐Quinney factors. The presented micromechanically motivated model describes non‐constant and non‐uniform latent energy storage effects. The Taylor‐Quinney factor has been computed for different isotropic hardening laws for illustration. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Uncertainty modeling in autonomous robust spacecraft system design
Authors: Fuchs Martin , Neumaier Arnold , Girimonte Daniela 
Published: September 2008

AbstractIn the last few years, much research has been dedicated to the development of decisions support systems for the space system engineers or even of completely automated design methods capturing the reasoning of the system experts. However, the problem of taking into account the uncertainties of the variables and models to determine an optimal and robust spacecraft design has not been tackled effectively yet. Based on the clouds formalism we propose a novel approach to process the uncertainty information provided by expert designers and incorporate it into the automated search for a robust optimal design. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical solution of the time‐dependent incompressible Navier‐Stokes equations in the stream function and vorticity formulation
Authors: Ghadi Fattehallah , Ruas Vitoriano , Wakrim Mohamed 
Published: September 2008

AbstractIn this work we study the time‐dependent incompressible Navier‐Stokes problem. We introduce a suitable technique based on the splitting of the vorticity into two components. Then we discretize in space the resulting uncoupled system by means of continuous Lagrange finite elements. This is achieved by first performing the semi‐discretization in time of these equations by a classical characteristics method for the advective term. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
SDP approximability of relative robust QP
Authors: Hauser Raphael , Tütüncü Reha 
Published: September 2008

AbstractWe consider a relative robust quadratic optimization problem with ellipsoidal uncertainty. This problem is generally NP‐hard, but we show how it can often be well approximated via a conic programming model. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bayesian signal restoration and Mumford‐Shah functional
Authors: Helin Tapio , Lassas Matti 
Published: September 2008

AbstractWe introduce a Bayesian signal restoration method which extracts jumps from a periodical signal. The maximum a posterior estimate of the model problem equals to a minimiser of a functional that Γ‐converges to the Mumford‐Shah functional. Furthermore, the behaviour of the approximative model in the infinite‐dimensional limit is discussed in more detail. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical analysis and algorithms in control and state constrained optimization with PDEs
Authors: Deckelnick Klaus , Günther Andreas , Hinze Michael 
Published: September 2008

AbstractWe consider an elliptic optimal control problem with control and pointwise state constraints. The cost functional is approximated by a sequence of functionals which are obtained by discretizing the state equation with the help of linear finite elements and enforcing the state constraints in the nodes of the triangulation. The control variable is not discretized. A general error bound for control and state is obtained which forms the starting point for optimal error estimates in both in two and three space dimensions. For the numerical implementation of the discrete concept fix‐point iterations or generalized Newton methods are proposed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling wave propagation phenomena in time domain by using the symmetric Galerkin BEM and the Convolution Quadrature Method
Authors: Kielhorn Lars , Schanz Martin 
Published: September 2008

AbstractThe boundary element method (BEM) is known to be well suited to treat wave propagation phenomena. Here, a 3‐d elastodynamic body is under consideration. For a numerical treatment of the underlying boundary integral equations appropriate time and spatial discretizations have to be introduced. The time discretization is done via the Convolution Quadrature Method (CQM) as proposed by Lubich while a symmetric Galerkin scheme is applied in space.Unfortunately, the symmetric Galerkin boundary element method (SGBEM) requires the use of the second boundary integral equation involving a hypersingular kernel. Therefore, an appropriate regularization of the hypersingular bilinear form has to be established.Finally, a numerical study show that the presented approach yields good convergence rates as well as good numerical stability properties. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interactions between compressibility and heat release in turbulent mixing layers
Authors: Mahle Inga , Friedrich Rainer 
Published: September 2008

AbstractReduced turbulence activity and growth rate of a compressible mixing layer when the convective Mach number increases, are well‐known phenomena. Heat release due to combustion has similar effects and important implications for applications such as scramjet engines the efficiency of which depends on a proper mixing of oxidizer and fuel. To understand the underlying mechanisms, highly resolved DNS of inert and reacting, temporally evolving mixing layers at different convective Mach numbers and Reynolds numbers ensuring a self‐similar state are performed and analyzed with a particular focus on the pressure‐strain correlations in the Reynolds‐stress transport equations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mathematical issues concerning the Boussinesq approximation for thermally coupled viscous flows
Authors: Díaz J. Ildefonso , Rakotoson Jean‐Michel , Schmidt Paul G. 
Published: September 2008

AbstractThe flow of a viscous fluid driven by buoyancy forces is governed by balance equations for momentum, mass, and internal energy. Frequently, the Boussinesq approximation is employed to simplify the system, even in situations where dissipative heating cannot be neglected. The resulting equations violate the principle of conservation of total energy, which causes significant mathematical problems. We discuss these problems and possible remedies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A two‐scale homogenization procedure for the meso‐macro‐modeling of electro‐mechanically coupled problems
Authors: Schröder Jörg 
Published: September 2008

AbstractThe challenge in the field of ferroelectric ceramics is the modeling of complicated interactions between electrical and mechanical properties of the material on the macro‐scale, caused by switching processes on the meso‐scale. This paper presents a two‐scale homogenization framework for the description of polycrystalline material behavior of ferroelectric ceramics, that takes into account the effects occurring on the meso‐scale. The macroscopic variables of the underlying field equations are expressed in terms of mesoscopic boundary integrals and appropriate boundary conditions on the meso‐scale are derived. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient numerical schemes for singularly perturbed parabolic initial‐boundary‐value problems
Authors: Natesan Srinivasan , Deb Rajdeep 
Published: September 2008

AbstractIn this article, we propose two efficient numerical schemes for singularly perturbed parabolic reaction‐diffusion initialboundary‐value problems. The spatial derivative is replaced by a hybrid scheme, which is a combination of the cubic spline and the classical central difference scheme in both the methods. In the first method, the time derivative is replaced by the Crank‐Nicolson scheme, whereas in the second method the time derivative is replaced by the extended‐trapezoidal scheme. These schemes are applied on the layer resolving piecewise‐uniform Shishkin mesh. Numerical examples show ε ‐uniform convergence results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multi‐phase field systems with anisotropic surface energies
Authors: Stinner Björn 
Published: September 2008

AbstractThe dynamics of phase boundaries in multi‐phase systems has been studied with a focus on interfacial energy contributions. A diffuse interface model based on the phase field methodology has been derived which, in the sharp interface limit, is related to a classical description with moving hypersurfaces modeling the phase boundaries. A nontrivial task in the case of multiple phases is to let the surface energies enter the equations of the diffuse interface model in the right way. A gradient potential and a multi‐well potential of obstacle type are presented that allow for a wide class of surface anisotropies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of microcracks in ferroelectric materials by application of a grain‐boundary‐motivated cohesive law
Authors: Utzinger J. , Menzel A. , Steinmann P. 
Published: September 2008

AbstractFerroelectric materials exhibit a huge potential for engineering applications – ranging from electrical actuators (inverse piezoelectric effect) to sensor technology (direct piezoelectric effect). To give an example, lead zirconate titanate (PZT) is a typical perovskite ion crystal possessing ferroelectric properties. In this contribution, we are particularly interested in the modelling of microcracking effects in ferroelectric materials.In view of Finite‐Element‐based simulations, the geometry of a natural grain structure, as observed on the so‐called micro‐level, is represented by an appropriate mesh. While the response on the grains themselves is approximated by coupled continuum elements, grain boundaries are numerically incorporated via so‐called cohesive‐type elements. For the sake of simplicity, switching effects in the bulk material will be neglected. The behaviour of the grain boundaries is modelled by means of cohesive‐type laws. Identifying grain boundaries as potential failure zones leading to microcracking, cohesive‐type elements consequently offer a great potential for numerical simulations. As an advantage, in the case of failure they do not a priori result in ill‐conditioned systems of equations as compared with the application of standard continuum elements to localised deformations. Finally, representative constitutive relations for both the bulk material and the grain boundaries, enable two‐dimensional studies of low‐cycle‐fatigue motivated benchmark boundary value problems. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)