bluuebunny/crossref_metadata_2025_split huggingface dataset:
Superoxide anion radical generation in the NaOH/H2O2/Fe(III) system: a spin trapping ESR study
Authors: Zhou Nie , Qiu Tian , Yang‐ping Liu , Yang Liu 
Published: November 2005

AbstractFormation of free radical intermediates in a NaOH/H2O2/Fe(III) system has been studied by ESR spectroscopy in the presence of the spin trap 5,5‐dimethy‐1‐pyrroline N‐oxide (DMPO). DMPO/O− and DMPO/•OH signals were simultaneously detected in this system, but only the DMPO/•OH signal could be observed in the absence of Fe(III). Effects of pH values and Fe(III) concentrations on the ESR signal intensities were investigated in detail. Formation of DMPO/O− adduct was inhibited by the addition of superoxide dismutase (SOD), catalase or nitro blue tetrazolium (NBT), and by chelating the Fe(III) with some chelators, including ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and desferrioxamine (DFO). Deoxygenation from the NaOH/H2O2/Fe(III) mixture had a slight effect on the formation of DMPO/O−. DMPO/O− signal was also detected from the NaOH/H2O2/Fe(II) mixture, but it can be totally suppressed under anaerobic conditions. Considering the hydrolysis of Fe(III) into polymerization iron species with oxide phases in the alkaline medium, Fe2O3 was directly suspended into a mixture of NaOH/H2O2 for comparison. Fortunately, the presence of Fe2O3 suspension was found to be of benefit to the production of DMPO/O−. Influence of aging time of hydrolytic iron species on the superoxide anion radical generation was also studied. These results suggest that the generation of O− from the NaOH/H2O2/Fe(III) system was probably caused by the heterogeneous surface catalysis initiated by hydrolytic iron species. Copyright © 2005 John Wiley & Sons, Ltd.
Sensitivities of flow and transport parameters in fractured porous media using automatic differentiation
Authors: Vogel T. , Bachmann D. , Hauschild A. , Bücker H. M. , Köngeter J. 
Published: November 2005

AbstractThe hydraulic complexity of hardrock aquifers with, for example, fast fluid flow in fractures, storage effects in the rock matrix, high contrasts in permeability, and a high spatial variability of structures requires a high standard of experimental and numerical techniques. This paper focuses on the interpretation of tracer tests. The sensitivity of tracer breakthrough curves with respect to flow and transport parameters is analysed for different model types in order to identify the relevant flow and transport processes. This leads to a better understanding of the system behaviour and facilitates the interpretation of experimental results. The technique of automatic differentiation is used to evaluate the sensitivities. The main advantage of this technique is that the sensitivities are calculated without truncation error. Copyright © 2005 John Wiley & Sons, Ltd.
Robust adaptive remeshing strategy for large deformation, transient impact simulations
Authors: Erhart Tobias , Wall Wolfgang A. , Ramm Ekkehard 
Published: November 2005

AbstractIn this paper, an adaptive approach, with remeshing as essential ingredient, towards robust and efficient simulation techniques for fast transient, highly non‐linear processes including contact is discussed. The necessity for remeshing stems from two sources: the capability to deal with large deformations that might even require topological changes of the mesh and the desire for an error driven distribution of computational resources. The overall computational approach is sketched, the adaptive remeshing strategy is presented and the crucial aspect, the choice of suitable error indicator(s), is discussed in more detail. Several numerical examples demonstrate the performance of the approach. Copyright © 2005 John Wiley & Sons, Ltd.
A methodology for the formulation of error estimators for time integration in linear solid and structural dynamics
Authors: Romero I. , Lacoma Luis M. 
Published: November 2005

AbstractIn this article, we present a novel methodology for the formulation of a posteriori error estimators applicable to time‐stepping algorithms of the type commonly employed in solid and structural mechanics. The estimators constructed with the presented methodology are accurate and can be implemented very efficiently. More importantly, they provide reliable error estimations even in non‐smooth problems where many standard estimators fail to capture the order of magnitude of the error. The proposed methodology is applied, as an illustrative example, to construct an error estimator for the Newmark method. Numerical examples of its performance and comparison with existing error estimators are presented. These examples verify the good accuracy and robustness predicted by the analysis. Copyright © 2005 John Wiley & Sons, Ltd.
Efficient iteration schemes for anisotropic hyperelasto‐plasticity
Authors: Ekh M. , Menzel A. 
Published: November 2005

AbstractNumerical issues arising when integrating hyperelasto‐plastic constitutive equations with elastic anisotropy, stemming from anisotropic damage, and plastic anisotropy as represented by kinematic hardening are discussed. In particular, solution algorithms for the corresponding non‐linear system of equations due to implicit integration algorithms are addressed. It is shown that algorithms like staggered iteration and quasi‐Newton techniques are superior to a pure Newton technique when the cpu time is compared. However, the drawback of the staggered and the quasi‐Newton technique is that rather small time steps must be taken to ensure convergence, which can be of importance when applying complex constitutive models in a finite element programme. Copyright © 2005 John Wiley & Sons, Ltd.
Skeletal reduction of boundary value problems
Authors: Suresh Krishnan 
Published: November 2005

AbstractBoundary value problems posed over thin solids are amenable to a dimensional reduction in that one or more spatial variables may be eliminated from the governing equation, resulting in significant computational gains with minimal loss in accuracy. Extant dimensional reduction techniques rely on representing the solid as a hypothetical mid‐surface plus a possibly varying thickness. Such techniques are however hard to automate since the mid‐surface is often ill‐defined and ambiguous.We propose here a skeletal representation based dimensional reduction of boundary value problems. The proposed technique has the computational advantages of mid‐surface reduction, but can be easily automated. A systematic methodology is presented for reducing boundary value problems to lower‐dimensional problems over the skeleton of a solid. The theoretical properties of the proposed method are derived, and supported by representative numerical experiments. Copyright © 2005 John Wiley & Sons, Ltd.
On the synthesis of time‐varying LQG weights and noises along optimal control and state trajectories
Authors: Van Willigenburg L. G. , De Koning W. L. 
Published: November 2005

AbstractA general approach to control non‐linear uncertain systems is to apply a pre‐computed nominal optimal control, and use a pre‐computed LQG compensator to generate control corrections from the on‐line measured data. If the non‐linear model, on which the optimal control and LQG compensator design is based, is of sufficient quality, and when the LQG compensator is designed appropriately, the closed‐loop control system is approximately optimal. This paper contributes to the selection and computation of the time‐varying LQG weighting and noise matrices, which determine the LQG compensator design. It is argued that the noise matrices may be taken time‐invariant and diagonal. Three very important considerations concerning the selection of the time‐varying LQG weighting matrices are turned into a concrete computational scheme. Thereby, the selection of the time‐varying LQG weighting matrices is reduced to selecting three scalar design parameters, each one weighting one consideration. Although the three considerations seem straightforward they may oppose one another. Furthermore, they usually result in time‐varying weighting matrices that are indefinite, rather than positive (semi) definite as required for the LQG design. The computational scheme presented in this paper addresses and resolves both problems. By two numerical examples the benefits of our optimal closed‐loop control system design are demonstrated and evaluated using Monte Carlo simulation. Copyright © 2005 John Wiley & Sons, Ltd.
Automatic Geometry Based FE Model Generation for Optimization and Robust Design for Passive Safety of Passenger Vehicles
Authors: Hilmann Joergen , Paas Michel , Schindler Volker 
Published: November 2005

AbstractIn this paper the optimization of large scale vehicle structures is addressed. A process strategy based on Latin Hypercube sampling, genetic algorithm optimization, and sensitivity analysis is discussed. This process was implemented on a dedicated Linux Cluster, utilizing various free and commercially available software tools, including SFE Concept, Perl, Matlab, and Radioss. The viability of the method is demonstrated for a large scale vehicle model in an offset deformable barrier crash test at 64 kph impact velocity. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Projected Gradient Flows for BV/Level Set Relaxation
Authors: Burger Martin , Hintermüller Michael 
Published: November 2005

AbstractThis paper introduces a new level set method based on projected gradient flows for problems that can be solved by a recently introduced relaxation approach. For the class of problems the relaxation is exact, it can be shown that the solution of the flow converges to a solution of the relaxed problem for large time, and the level sets of the limit are solutions of the original problem. We introduce a simple computational scheme based on explicit time discretization and apply the method to imaging examples. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parallel Solution Methods for Porous Media Models in Biomechanics
Authors: Wieners C. , Ehlers W. , Ammann M. , Karajan N. , Markert B. 
Published: November 2005

AbstractWe present a biomechanical application of our parallel finite element model for coupled problems in solid mechanics. This programming framework provides a very lean and flexible interface, which allows to realize time‐dependent nonlinear simulations. In this context, a special variant of a stabilized local Gauß‐Seidel preconditioner is introduced, which can be successfully employed to large scale computations. Finally, the efficiency of the implemented algorithm is shown by a numerical example considering the axial compression of a L4‐L5 motion segment of the spine. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gradient evaluation in DAE optimal control problems by sensitivity equations and adjoint equations
Authors: Gerdts Matthias 
Published: November 2005

AbstractThe problem of calculating gradients for discretized optimal control problems is addressed. These gradients are needed by a sequential quadratic programming (SQP) method, which is used to solve the discretized optimal control problem. Two approaches for gradient calculation are discussed and compared numerically. The first approach uses sensitivity equations, the second uses adjoint equations. It turns out that it depends on the problem dimensions which approach is more preferable compared to the other. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Towards Matrix‐Free AD‐Based Preconditioning of KKT Systems in PDE‐Constrained Optimization
Authors: Griesse Roland , Walther Andrea 
Published: November 2005

AbstractThe presented approach aims at solving an equality constrained, finite‐dimensional optimization problem, where the constraints arise from the discretization of some partial differential equation (PDE) on a given space grid. For this purpose, a stationary point of the Lagrangian is computed using Newton's method, which requires the repeated solution of KKT systems. The proposed algorithm focuses on two topics: Firstly, Algorithmic Differentiation (AD) will be used to evaluate the necessary computations of gradients, Jacobian‐vector products, and Hessian‐vector products, so that only the objective f (y , u ) and the PDE constraint e (y , u ) = 0 have to be specified by the user. Secondly, we solve the KKT system iteratively using the QMR algorithm, with preconditioning provided by a multigrid approach. We wish to explore whether the Jacobian‐vector products provided by AD are sufficient to construct suitable multigrid preconditioners. Our approach is then embedded into a globalized optimization routine. Numerical results for optimization problems involving a nonlinear reaction‐diffusion model will be given. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rearrangement of chromosomal region 8q11–13 in lipomatous tumours: correlation with lipoblastoma morphology
Authors: Brandal Petter , Bjerkehagen Bodil , Heim Sverre 
Published: November 2005

AbstractCytogenetics is of considerable value when diagnosing lipomatous tumours, as different tumour types have different more or less specific chromosomal abnormalities. One such entity is lipoblastoma, which is a benign lipomatous tumour that often exhibits rearrangements of chromosome bands 8q11–13, and the gene PLAG1 has been implicated as the target of these chromosomal changes. All lipomatous tumours karyotyped at the Norwegian Radium Hospital were reviewed, looking for rearrangements of 8q11–13. Five tumours exhibiting chromosomal abnormalities affecting this region were found. Only one of them was morphologically diagnosed as a lipoblastoma, two being classified as lipomas, one as a hibernoma, and one as a well‐differentiated liposarcoma. The two tumours successfully analysed with bacterial artificial chromosomes (BACs) covering the gene PLAG1 showed involvement of this gene in the rearrangement. The findings raise the question as to what extent the diagnosis lipoblastoma should be based on histopathological or cytogenetic/molecular data or a combination thereof. When karyotypic information from this series was combined with available literature data, it was found that the sensitivity of 8q11–13 rearrangements for diagnosing lipoblastomas when found in a lipomatous tumour was 77% and that the corresponding specificity was 98%. The validity of these calculations of the diagnostic information provided by the cytogenetic findings is, of course, totally dependent on the morphological diagnosis made in each case. Regardless of what the precise phenotypic diagnosis was, it is suggested that lipomatous tumours with 8q11–13 rearrangement constitute a distinct pathogenetic entity. When selective therapies tailor‐made against the specific pathogenetic rearrangement become available, it will become mandatory to pay more attention to the genetic constitution of the tumour cells than to their phenotypic appearance. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Fatal pneumonitis in children with metastatic rhabdomyosarcoma following whole lung radiotherapy and sequential epirubicin
Authors: Prestwich R.J. , Picton S.V. , Glaser A. , Taylor R.E. 
Published: November 2005

AbstractInterstitial pneumonitis is a recognized complication following whole lung radiotherapy. We report two cases in which fatal pneumonitis appeared to be precipitated by the administration of epirubicin‐containing combination chemotherapy within 7 weeks of completion of whole lung radiotherapy. These cases highlight a potentially fatal interaction between radiotherapy and modern chemotherapy regimens. Pediatr Blood Cancer 2007;48:586–590. © 2005 Wiley‐Liss, Inc.
Sinus histiocytosis with massive lymphadenopathy (Rosai–Dorfman disease) treated with 2‐chlorodeoxyadenosine
Authors: Tasso M. , Esquembre C. , Blanco E. , Moscardó C. , Niveiro M. , Payá A. 
Published: November 2005

AbstractSinus histiocytosis with massive lymphadenopathy (SHML) or Rosai–Dorfman disease (RDD) is a rare but well‐defined histiocytic proliferative disorder of unknown etiology that usually presents with cervical lymphadenopathy, fever, leukocytosis, and hypergammaglobulinemia in an otherwise healthy child. Although many patients undergo spontaneous remission, a subset of patients with systemic disease has a more serious course. For those patients with a poor outcome, steroids and chemotherapeutic agents such as etoposide or 6‐mercaptopurine plus low dose methotrexate have been used. We present a child with a massive cervical lymphadenopathy treated with 2‐chlorodeoxyadenosine (2‐CdA, cladribine) after other approaches failed. Pediatr Blood Cancer 2006; 47:612–615. © 2005 Wiley‐Liss, Inc.
Continuous or repeated prolonged cisplatin infusions in children: A prospective study on ototoxicity, platinum concentrations, and standard serum parameters
Authors: Lanvers‐Kaminsky C. , Krefeld B. , Dinnesen A.G. , Deuster D. , Seifert E. , Würthwein G. , Jaehde U. , Pieck A.C. , Boos J. 
Published: November 2005

AbstractBackgroundTo overcome the ototoxicity of cisplatin, single bolus infusions were replaced by repeated prolonged infusions of lower doses or by continuous infusions at still lower infusion rates. However, considering ototoxicity little is, in fact, known about the tolerance of repeated prolonged or continuous infusion in children.ProcedureAuditory function was monitored along with plasma concentrations of free and total platinum (Pt), and with standard serum parameters (sodium, potassium, calcium, magnesium, phosphate, chloride, and creatinine) in 24 children receiving cisplatin by continuous infusion for the treatment of neuroblastoma and osteosarcoma or by repeated 1 or 6 hr infusions for the treatment of germ cell tumors.ResultsHearing deteriorated in 10/15 osteosarcoma patients, 2/3 neuroblastoma patients, and 1/6 patients with germ cell tumors. Ototoxicity occurred after cumulative doses between 120 and 360 mg/m2 cisplatin. In osteosarcoma patients, ototoxicity was associated with a comparatively higher mean plasma concentration of free Pt. However, Pt plasma concentrations did not discriminate between patients with or without ototoxicity. In patients experiencing ototoxicity serum creatinine increased by 45% compared to pre‐treatment levels (mean). Serum creatinine increased by 26% in patients without ototoxicity (P < 0.05, Mann–Whitney Rank sum test). Despite standardized hydration, discrete but significant changes of potassium, sodium, magnesium, and phosphate were observed during and/or after cisplatin infusion, which, however, did not discriminate between patients with and without ototoxicity.ConclusionsWhile continuous cisplatin infusions are less nephrotoxic than repeated prolonged infusions, we observed considerable ototoxicity in patients treated with continuous cisplatin infusions, which necessitates further evaluations on the tolerance of continuous cisplatin infusions in children. Pediatr Blood Cancer © 2005 Wiley‐Liss, Inc.
Response to vinorelbine and low‐dose cyclophosphamide chemotherapy in two patients with desmoplastic small round cell tumor
Authors: Ferrari Andrea , Grosso Federica , Stacchiotti Silvia , Meazza Cristina , Zaffignani Elena , Marchianò Alfonso , Casanova Michela 
Published: November 2005

AbstractWe report two cases of abdominal desmoplastic small round cell tumor (DSRCT) that showed a clinical response to the vinorelbine/low‐dose cyclophosphamide combination that has been claimed to be effective for rhabdomyosarcoma. This observation may prompt further investigation into the activity of such a regimen in DSRCT patients with recurrent or refractory disease, with a view to a possible future role as maintenance therapy in controlling minimal residual disease in patients who achieve complete remission with intensive induction multimodality therapy. Pediatr Blood Cancer 2007;49:864–866. © 2005 Wiley‐Liss, Inc.
Diagnosis of Burkitt lymphoma in pediatric patients by thoracentesis
Authors: McLean Thomas W. , Farber Rebecca S. , Lewis Zachary T. , Wofford Marcia M. , Pettenati Mark J. , Pranikoff Thomas , Chauvenet Allen R. 
Published: November 2005

AbstractThe diagnosis of Burkitt lymphoma by thoracentesis has been rarely reported in the literature, particularly in children. From 1995 to 2004, we diagnosed six pediatric patients with mature B‐cell neoplasms using thoracentesis as the initial diagnostic procedure. The cytology, immunophenotyping, and cytogenetic results of the pleural fluid cells were consistent with mature B‐cell malignancies. We conclude that thoracentesis for the diagnosis of Burkitt lymphoma in children is safe, fast, and accurate. It should be strongly considered as an initial diagnostic procedure for pediatric patients with pleural effusions who are suspected of having B‐cell malignancies. Pediatr Blood Cancer 2007;49:90–92. © 2005 Wiley‐Liss, Inc.
Minimal residual disease (MRD) measurement as a tool to compare the efficacy of chemotherapeutic drug regimens using Escherichia Coli‐asparaginase or Erwinia‐asparaginase in childhood acute lymphoblastic leukemia (ALL)
Authors: Kwok Cecilia Sze , Kham Shirley Kow , Ariffin Hany , Lin Hai Peng , Quah Thuan Chong , Yeoh Allen Eng 
Published: November 2005

AbstractBackgroundL‐asparaginase is a crucial drug in childhood acute lymphoblastic leukemia (ALL) induction therapy, but much debate remains regarding the optimal formulation and dosage. As minimal residual disease (MRD) can accurately measure extremely low levels of lymphoblasts, it is a sensitive reflection of leukemia cell kill. We utilized MRD to compare the efficacy of Erwinia‐asparaginase (Erwinia‐asp) and E. coli‐asparaginase (E. coli‐asp) during induction therapy for childhood ALL.ProcedureOf 116 precursor‐B ALL patients, 22 were treated with Erwinia‐asp, 90 with E. coli‐asp, and 4 were switched from E. coli‐asp to Erwinia‐asp. MRD levels at the end of induction were analyzed for 90 patients (Erwinia‐asp = 16; E. coli‐asp = 74). Patients were stratified into MRD ≥10−2, between 10−2–10−4 and ≤10−4. Toxicity information during induction was available for 110 patients.ResultsMRD was the only significant prognosticator compared to conventional criteria. Patients treated with Erwinia‐asp were 6.7 times more likely to have MRD levels ≥10−2 (P = 0.031), reflecting slower lymphoblast clearance. While non‐asparaginase related toxicities were similar in both groups, more E. coli‐asp patients experienced severe asparaginase‐related toxicity.ConclusionE. coli‐asp is superior to Erwinia‐asp in childhood ALL induction. Although E. coli‐asp is more toxic, this is balanced by better response to therapy. Early response to treatment as measured by MRD is a direct reflection of leukemic cell kill and is a significant prognosticator of eventual outcome, making it a good surrogate marker to evaluate the efficacy of induction drugs in childhood ALL. Pediatr Blood Cancer 2006;47:299–304. © 2005 Wiley‐Liss, Inc.
Autologous transplantation of CD133 selected hematopoietic progenitor cells for treatment of relapsed acute lymphoblastic leukemia
Authors: Barfield R.C. , Hale G.A. , Burnette K. , Behm F.G. , Knapp K. , Eldridge P. , Handgretinger R. 
Published: November 2005

AbstractA 21‐year‐old white male with relapsed acute lymphoblastic leukemia (ALL) developed an invasive Zygomycosis infection 3 weeks after beginning re‐induction chemotherapy. Because of the high risk of fatal recurrence of the fungal infection, neither long‐term maintenance chemotherapy nor allogeneic hematopoietic stem cell transplant (HSCT) was considered appropriate. Because his ALL blasts expressed CD34 but lacked CD133, he received a CD133 selected autologous graft following high‐dose consolidation chemotherapy. The patient survives in remission 19 months after HSCT. Pediatr Blood Cancer 2007;48:349–353. © 2005 Wiley‐Liss, Inc.