bluuebunny/crossref_metadata_2025_split huggingface dataset:
The classical kinetic model for radical chain oxidation of hydrocarbon substrates initiated by bimolecular hydroperoxide decomposition
Authors: Colin X. , Fayolle B. , Audouin L. , Verdu J. 
Published: September 2006

AbstractKinetic modeling of the low‐temperature (typically T ⩽ 200°C) thermal aging of polymers is a problem of great technological importance, owing to the continuously increasing needs of industry in terms of reliable methods for lifetime prediction. In the temperature domain under consideration, for most hydrocarbon substrates, oxidation proceeds by a radical chain reaction initiated by bimolecular hydroperoxide decomposition. In other words, the reaction generates its own initiator, which explains its strong autoaccelerated character. The most pertinent model is, to our opinion, the model elaborated by Tobolsky et al. (J Am Chem Soc 1950, 72, 1942) in the early 1950s. This model is, however, based on three questionable assumptions: the existence of a stationary state for radical concentrations (hypothesis S), the presence of oxygen in excess (hypothesis E), and the fact that the onset of steady state can be observed in the domain of low conversions, where the substrate consumption can be neglected (hypothesis L). One hypothesis (S) lacks consistency. A sounder alternative, which does not modify significantly the mathematical expressions of the model, will be proposed. The other hypotheses (E and L) can be justified in certain cases, but the limits of their domain of validity were never established to our knowledge. It is tried, here, to express these limits in function of fundamental parameters: rate constants and concentrations of reactants. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38:666–676, 2006
Increase in body weight after pramipexole treatment in Parkinson's disease
Authors: Kumru Hatice , Santamaria Joan , Valldeoriola Francesc , Marti Maria J. , Tolosa Eduardo 
Published: September 2006

AbstractBody weight changes occur during the clinical course of Parkinson's disease (PD) and with surgical treatment, but the effect of dopaminergic treatment on weight is unknown. Body mass index (BMI), Hamilton depression scale score (HDS), and Unified Parkinson's Disease Rating Scale III (UPRS‐III) were measured before and 3 months after starting pramipexole in 28 PD patients. Pramipexole produced a significant weight increase, as well as motor and mood improvement (P <0.001). HDS and BMI changes were mildly related (P = 0.05). A direct effect of pramipexole on limbic D3 receptors involved in the control of feeding may be responsible for weight gain in PD.
© 2006 Movement Disorder Society
Clinical response to varying the stimulus parameters in deep brain stimulation for essential tremor
Authors: Kuncel Alexis M. , Cooper Scott E. , Wolgamuth Barbara R. , Clyde Merlise A. , Snyder Scott A. , Montgomery Erwin B. , Rezai Ali R. , Grill Warren M. 
Published: September 2006

AbstractDeep brain stimulation (DBS) of the ventral intermediate nucleus of the thalamus for essential tremor is sometimes limited by side effects. The mechanisms by which DBS alleviates tremor or causes side effects are unclear; thus, it is difficult to select stimulus parameters that maximize the width of the therapeutic window. The goal of this study was to quantify the impact on side effect intensity (SE), tremor amplitude, and the therapeutic window of varying stimulus parameters. Tremor amplitude and SE were recorded at 40 to 90 combinations of pulse width, frequency, and voltage across 14 thalami. Posterior variable inclusion probabilities indicated that frequency and voltage were the most important predictors of both SE and tremor amplitude. The amount of tremor suppression achieved at frequencies of 90 to 100 Hz was not different from that at 160 to 170 Hz. However, the width of the therapeutic window decreased significantly and power consumption increased as frequency was increased above 90 to 100 Hz. Improved understanding of the relationships between stimulus parameters and clinical responses may lead to improved techniques of stimulus parameter adjustment. © 2006 Movement Disorder Society
Involuntary painful muscle contractions in Satoyoshi syndrome: A surface electromyographic study
Authors: Drost Gea , Verrips Aad , van Engelen Baziel G.M. , Stegeman Dick F. , Zwarts Machiel J. 
Published: September 2006

AbstractWe report a child with Satoyoshi syndrome manifested by involuntary painful muscle contractions and alopecia. Although an autoimmune origin of Satoyoshi syndrome seems likely, its exact etiology remains as yet unknown, as is the origin of the involuntary contractions. To gain a better understanding of the electrophysiological characteristics of the involuntary contractions, we performed a surface electromyographic (EMG) study. We investigated muscle contractions in the legs using two noninvasive techniques: high‐density surface EMG (HD‐sEMG) recordings on one muscle, and polymyographic surface EMG (sEMG) recordings on various muscles. During the involuntary contractions, HD‐sEMG showed a fourfold increase in amplitude compared to maximal voluntary contractions. These high potentials were widely distributed across the whole muscle and showed a pronounced oscillatory behavior with a frequency around 45 Hz. Polymyographic sEMG revealed that the involuntary contractions often occur simultaneously in various muscles or showed a switch of activity from one muscle to another. These findings point to hyperactivity or a disinhibition at the alpha motor neuron level, originating probably at that level, although a central origin cannot be excluded. © 2006 Movement Disorder Society
Spectral properties and regularity of solutions to transport equations in slab geometry
Authors: Latrach Khalid , Megdiche Hatem 
Published: September 2006

AbstractThis paper deals with regularity properties of solutions to Cauchy problems governed by one‐dimensional transport equations for a wide class of anisotropic scattering operators and a variety of boundary conditions which cover, in particular, the classical known ones. Under adequate assumptions, various descriptions of the large time behaviour of solutions are derived. Copyright © 2006 John Wiley & Sons, Ltd.
Asymptotic analysis of elastic curved rods
Authors: Vodák Rostislav 
Published: September 2006

AbstractWe consider a sequence of curved rods which consist of isotropic material and which are clamped on the lower base or on both bases. We study the asymptotic behaviour of the stress tensor and displacement under the assumptions of linearized elasticity when the cross‐sectional diameter of the rods tends to zero and the body force is given in the particular form. The analysis covers the case of a non‐smooth limit line of centroids. We show how the body force and the choice of the approximating curved rods can affect the strong convergence and the limit form of the stress tensor for the curved rods clamped on both bases. Copyright © 2006 John Wiley & Sons, Ltd.
Instantaneous control for traffic flow
Authors: Herty M. , Kirchner C. , Klar A. 
Published: September 2006

AbstractThe solution methods for optimal control problems with coupled partial differential equations as constraints are computationally costly and memory intensive; in particular for problems stated on networks, this prevents the methods from being relevant. We present instantaneous control problems for the optimization of traffic flow problems on road networks. We derive the optimality conditions, investigate the relation to the full optimal control problem and prove that certain properties of the optimal control problem carry over to the instantaneous one. We propose a solution algorithm and compare quality of the computed controls and run‐times. Copyright © 2006 John Wiley & Sons, Ltd.
A least‐squares method for axisymmetric div–curl systems
Authors: Copeland Dylan M. , Pasciak Joseph E. 
Published: September 2006

AbstractWe present a negative‐norm least‐squares method for axisymmetric div–curl systems arising from Maxwell's equations for electrostatics and magnetostatics in three dimensions. The method approximates the solution in a two‐dimensional meridian plane. To achieve this dimension reduction, we must work with weighted spaces in cylindrical co‐ordinates. In this setting, a stable pair of approximation spaces is developed and analysed. We also report the results of some numerical experiments, which demonstrate a quasi‐optimal convergence rate and a robustness with respect to the domain and coefficients. Copyright © 2006 John Wiley & Sons, Ltd.
Survival, mortality, and complications in patients with β‐Thalassemia major in northern Taiwan
Authors: Chern Jimmy P. S. , Su Syi , Lin Kai‐Hsin , Chang Shu‐Hui , Lu Meng‐Yao , Jou Shiann‐Tarng , Lin Dong‐Tsamn , Ho Wan‐Ling , Lin Kuo‐Sin 
Published: September 2006

AbstractBackgroundAdvances in treatment have improved the prognosis in β‐thalassemia major. We present the survival and complications pattern of those patients in northern Taiwan born after 1970.ProcedureOne‐hundred and sixty patients with β‐thalassemia major born after 1970 were collected. The Kaplan–Meier method and log‐rank test were used to estimate and compare survival. Cox regression models were used to examine the associations of bone marrow transplantation (BMT), time of BMT procedure, and time of complications with survival.ResultsBetter survival was observed for patients born after 1980 (P = 0.0121). Heart disease, BMT‐related deaths, and infections were the main causes of death. Among the living patients over age 15, hypogonadotropic hypogonadism, HCV infection, diabetes, heart failure, and arrhythmia were the common complications. No patients under age 15 had complications.ConclusionsSurvival for patients with β‐thalassemia major has improved significantly in Taiwan. More time is required to demonstrate whether these modalities added to the treatment of these patients will impact favorably on their outcome. Our success with BMT is improving and we are now in a position to offer this curative alternative. Pediatr Blood Cancer 2007;48:550–554. © 2006 Wiley‐Liss, Inc.
Symptoms in the palliative phase of children with cancer
Authors: Theunissen J.M.J. , Hoogerbrugge P.M. , van Achterberg T. , Prins J.B. , Vernooij‐Dassen M.J.F.J. , van den Ende C.H.M. 
Published: September 2006

AbstractBackgroundThe aim of the study was to make a comprehensive inventory of the physical, psychological, and social symptoms of children with cancer and their parents during the palliative phase and the extent to which health professionals address those symptoms.ProcedureForty parents of children who died 1–3 years prior to data collection (structured questionnaire) were invited to participate in the study.ResultsThe response rate was 32 out of 40 parents (80%). Most frequently mentioned physical symptoms were pain, poor appetite, and fatigue. The children's most mentioned psychological symptoms were sadness, difficulty in talking to their parents about their feelings regarding illness and death and fear of being alone. The symptoms of fear of death of the child and fear of physical symptoms were most frequently mentioned parents' psychological symptoms. Health professionals addressed 82% of the children's physical symptoms, 43% of the children's psychological symptoms, and 56% of the parents' psychological symptoms. Parents indicated that after professional attention the proportion of children's physical symptoms that were completely or partially resolved was 18 and 26%, respectively. For children's psychological symptoms the figures were 9 and 25%, respectively, and for parents' psychological symptoms 2 and 23%, respectively.ConclusionsThe burden of symptoms of the child with cancer during the palliative phase and their parents is high. Health professionals focus mainly on the physical symptoms of the child. Relief of symptoms could not be achieved for a large proportion of symptoms. Further prospective research is necessary to investigate the kind, frequency and intensity of symptoms in order to tailor optimal palliative care to the needs of both child and parent. Pediatr Blood Cancer 2007;49:160–165. © 2006 Wiley‐Liss, Inc.
A phase II trial of thalidomide and cyclophosphamide in patients with recurrent or refractory pediatric malignancies
Authors: Gilheeney Stephen W. , Lyden David C. , Sgouros Shirley , Antunes Nuno , Gerald William , Kramer Kim , Lis Eric , Meyers Paul , Rosen Nancy , Thaler Howard T. , Trippett Tanya , Wexler Leonard , Dunkel Ira J. 
Published: September 2006

AbstractBackgroundPrevious clinical and pre‐clinical research has demonstrated synergy between anti‐angiogenic agents and cytotoxic chemotherapy. This trial was undertaken to investigate whether the combination of cyclophosphamide and thalidomide would be active against pediatric tumors.ProcedurePatients with pediatric malignancies who had no remaining conventional therapeutic options were recruited from January 1999 to May 2001. They received thalidomide (6–12 mg/kg po every day; maximum daily dose 800 mg) and cyclophosphamide (1,200 mg/m2 IV every 28 days).ResultsTwenty‐seven patients were enrolled on the study. Seventeen were male and 10 were female. Median age at the time of registration was 15 years (range 1–54 years). The median number of prior treatment regimens was four. Twenty‐one patients were evaluable for response; 1 had a partial response (Hodgkin disease), 1 demonstrated stable disease (neuroendocrine tumor), and 19 had progressive disease. The most common toxicities were hematological (leukocytopenia and neutropenia) and gastrointestinal. One patient experienced a grade 3 rash. Fatigue and daytime somnolence were variable. No peripheral neuropathy was observed.ConclusionThe combination of thalidomide and cyclophosphamide as described herein has a modest and tolerable toxicity profile but little evidence of efficacy. Pediatr Blood Cancer 2007;49:261–265. © 2006 Wiley‐Liss, Inc.
Synthesis, characterization, and molecular modeling studies of novel polyurethanes based on 2,2′‐[ethane‐1,2‐diylbis(nitrilomethylylidene)]diphenol and 2,2′‐[hexane‐1,6‐diylbis(nitrilomethylylidene)] diphenol hard segments
Authors: Raghu A. V. , Gadaginamath G. S. , Jawalkar S. S. , Halligudi S. B. , Aminabhavi T. M. 
Published: September 2006

AbstractNovel polyurethanes (PUs) based on 2,2′‐[ethane‐1,2‐diylbis(nitrilomethylylidene)]diphenol and 2,2′‐[hexane‐1,6‐diylbis(nitrilomethylylidene)]diphenol as hard segments containing four aromatic diisocyanates (4,4′‐diphenylmethane diisocyanate, toluene 2,4‐diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate) have been prepared. Fourier transform infrared, UV spectrophotometry, fluorescence spectroscopy, 1H NMR and 13C NMR spectroscopy, thermogravimetric analysis, and differential thermal analysis have been used to determine the structural characterization and thermal properties of the segmented PUs. All the PUs contain domains of both semicrystalline and amorphous structures, as indicated by X‐ray diffraction. The acoustic properties have been calculated with the group contribution method. Molecular dynamics simulations have been performed on all the PUs to estimate the cohesive energy density and solubility parameter values, which compare well with the values calculated with the group contribution method. Furthermore, the simulation protocols have been applied to the PUs to produce X‐ray diffraction plots to determine the phase morphology of the PUs. The surface properties of the PUs have been estimated from the simulation protocols. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6032–6046, 2006
Characterization and tissue‐specific expression of two lepidopteran farnesyl diphosphate synthase homologs: Implications for the biosynthesis of ethyl‐substituted juvenile hormones
Authors: Cusson Michel , Béliveau Catherine , Sen Stephanie E. , Vandermoten Sophie , Rutledge Robert G. , Stewart Don , Francis Frédéric , Haubruge Éric , Rehse Peter , Huggins David J. , Dowling Ashley P.G. , Grant Guy H. 
Published: September 2006

AbstractThe sesquiterpenoid juvenile hormone (JH) regulates insect development and reproduction. Most insects produce only one chemical form of JH, but the Lepidoptera produce four derivatives featuring ethyl branches. The biogenesis of these JHs requires the synthesis of ethyl‐substituted farnesyl diphosphate (FPP) by FPP synthase (FPPS). To determine if there exist more than one lepidopteran FPPS, and whether one FPPS homolog is better adapted for binding the bulkier ethyl‐branched substrates/products, we cloned three lepidopteran FPPS cDNAs, two from Choristoneura fumiferana and one from Pseudaletia unipuncta. Amino acid sequence comparisons among these and other eukaryotic FPPSs led to the recognition of two lepidopteran FPPS types. Type‐I FPPSs display unique active site substitutions, including several in and near the first aspartate‐rich motif, whereas type‐II proteins have a more “conventional” catalytic cavity. In a yeast assay, a Drosophila FPPS clone provided full complementation of an FPPS mutation, but lepidopteran FPPS clones of either type yielded only partial complementation, suggesting unusual catalytic features and/or requirements of these enzymes. Although a structural analysis of lepidopteran FPPS active sites suggested that type‐I enzymes are better suited than type‐II for generating ethyl‐substituted products, a quantitative real‐time PCR assessment of their relative abundance in insect tissues indicated that type‐I expression is ubiquitous whereas that of type‐II is essentially confined to the JH‐producing glands, where its transcripts are ∼20 times more abundant than those of type‐I. These results suggest that type‐II FPPS plays a leading role in lepidopteran JH biosynthesis in spite of its apparently more conventional catalytic cavity. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Structure modeling, ligand binding, and binding affinity calculation (LR‐MM‐PBSA) of human heparanase for inhibition and drug design
Authors: Zhou Zhigang , Bates Maria , Madura Jeffry D. 
Published: September 2006

AbstractHuman heparanase is an endo‐β‐D‐glycosidase that cleaves heparan sulphate (HS) chains in the extracellular matrix and basement membrane. It is known that the cleavage of HS by heparanase results in cell invasion and metastasis of cancer. Therefore, heparanase is considered an important target for cancer drug development. The three‐dimensional structure of heparanase would be useful in the rational design of inhibitors targeted to the enzyme; however, the three‐dimensional structure has not yet been determined. In our effort to design inhibitors, we developed a three‐dimensional structure of heparanase using a homology‐modeling approach. The homology‐built structure is consistent to previous bioinformatics and site‐mutation experimental results. The heparanase features a (α/β)8 TIM‐barrel fold with two glutamate residues (Glu225 and Glu343) located in the active‐site cleft. This feature supports the putative mechanism of proton donor and nucleophilic sites. Docking simulations yielded 41 complex structures, which indicate that the bound inhibitor could block ligand binding into the catalytic site. A free energy of binding model was established for 25 heparanase inhibitors with a training set of 25 heparanase inhibitors using the linear response MM‐PBSA approach (LR‐MM‐PBSA). The correlation between calculated and experimental activity was 0.79 and the reliability of the model was validated with leave‐one‐out cross‐validation method. Its predictive capability was further validated using a test set of 16 inhibitors similar to the training set of inhibitors. The correlation between the predicted and observed activities is significantly improved by the protein “induced‐fit” that accounts for the flexibility of the receptor. These interaction and pharmacophore elements provide a unique insight to the rational design of new ligands targeted to the enzyme. Proteins 2006. © 2006 Wiley‐Liss, Inc.
ROSETTALIGAND: Protein–small molecule docking with full side‐chain flexibility
Authors: Meiler Jens , Baker David 
Published: September 2006

AbstractProtein–small molecule docking algorithms provide a means to model the structure of protein–small molecule complexes in structural detail and play an important role in drug development. In recent years the necessity of simulating protein side‐chain flexibility for an accurate prediction of the protein–small molecule interfaces has become apparent, and an increasing number of docking algorithms probe different approaches to include protein flexibility. Here we describe a new method for docking small molecules into protein binding sites employing a Monte Carlo minimization procedure in which the rigid body position and orientation of the small molecule and the protein side‐chain conformations are optimized simultaneously. The energy function comprises van der Waals (VDW) interactions, an implicit solvation model, an explicit orientation hydrogen bonding potential, and an electrostatics model. In an evaluation of the scoring function the computed energy correlated with experimental small molecule binding energy with a correlation coefficient of 0.63 across a diverse set of 229 protein– small molecule complexes. The docking method produced lowest energy models with a root mean square deviation (RMSD) smaller than 2 Å in 71 out of 100 protein–small molecule crystal structure complexes (self‐docking). In cross‐docking calculations in which both protein side‐chain and small molecule internal degrees of freedom were varied the lowest energy predictions had RMSDs less than 2 Å in 14 of 20 test cases. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Homology modeling and molecular dynamics study of West Nile virus NS3 protease: A molecular basis for the catalytic activity increased by the NS2B cofactor
Authors: Zhou Hong , Singh N. Jiten , Kim Kwang S. 
Published: September 2006

AbstractThe West Nile virus (WNV) NS3 serine protease, which plays an important role in assembly of infective virion, is an attractive target for anti‐WNV drug development. Cofactors NS2B and NS4A increase the catalytic activity of NS3 in dengue virus and Hepatitis C virus, respectively. Recent studies on the WNV‐NS3 characterize the catalytically active form of NS3 by tethering the 40‐residue cofactor NS2B. It is suggested that NS2B is essential for the NS3 activity in WNV, while there is no information of the WNV‐NS3‐related crystal structure. To understand the role of NS2B/substrate in the NS3 catalytic activity, we built a series of models: WNV‐NS3 and WNV‐NS3‐NS2B and WNV‐NS3‐NS2B‐substrate using homology modeling and molecular modeling techniques. Molecular dynamics (MD) simulations were performed for 2.75 ns on each model, to investigate the structural stabilization and catalytic triad motion of the WNV NS3 protease with and without NS2B/substrate. The simulations show that the NS3 rearrangement occurs upon the NS2B binding, resulting in the stable D75‐OD1…H51‐NH hydrogen bonding. After the substrate binds to the NS3–NS2B active site, the NS3 protease becomes more stable, and the catalytic triad is formed. These results provide a structural basis for the activation and stabilization of the enzyme by its cofactor and substrate. by its cofactor and substrate. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Quantum chemical study of cyclic dipeptides
Authors: Zhu Yanyan , Tang Mingsheng , Shi Xiaoyu , Zhao Yufen 
Published: September 2006

AbstractThe preferred conformations of cyclic dipeptides were first studied systemically using the density functional theory (DFT) B3LYP method at the 6‐31G(d) level. The structural characteristics of cyclic dipeptides were revealed, most of which have not been confirmed until now. Our studies showed that the six‐member main circles of cyclic dipeptides composed of natural L‐amino acid residues appeared as boat conformations. The important factors that influence conformations of cyclic dipeptides, such as molecular total energy, nuclear repulsion energy, molecular orbit, spatial effects, and reactive mechanism, are discussed in detail. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007