bluuebunny/crossref_metadata_2025_split huggingface dataset:
The differential effects of the radioprotectant drugs amifostine and sodium selenite treatment in combination with radiation therapy on constituent bone cells, ewing's sarcoma of bone tumor cells, and rhabdomyosarcoma tumor cells in vitro
Authors: Margulies Bryan S. , Damron Timothy A. , Allen Matthew J. 
Published: May 2008

AbstractThe purpose of this study was to determine the differential effects of therapeutic X‐radiation on constituent bone cells relative to the pediatric tumor cells: Ewing's sarcoma of bone and rhabdomyosarcoma. In addition, the radioprotectant drugs amifostine and sodium selenite were administered to constituent bone cells and the two tumor cells to determine if the radioprotectants differentially protect bone cells while not benefiting the tumor cells. These studies are a necessary first step in determining the potential clinical benefit of radioprotective therapy. An established in vitro cell culture model employing both constituent bone cells (osteoblasts, primary bone marrow monocytes, osteoclasts chondrocytes, and endothelial cells) and the tumor cells lines (Ewing's sarcoma of bone and rhabdomyosarcoma) were exposed to irradiation, amifostine, and sodium selenite. Cells were then assayed for changes in cell number, cytotoxicity, mineralization, bone resorption, cell attachment, osteocalcin, caspase‐3 expression, clonogenic survival, and alkaline phosphatase expression. Radiation therapy differentially decreased cell number; with osteoblasts being shown to be the least sensitive to irradiation, the tumor cells had an intermediate sensitivity and monocytes were the most sensitive. Both amifostine and sodium selenite protected chondrocytes and osteoblasts from the negative effects of irradiation, while not protecting the tumor cells. The pediatric tumor cell lines were generally more radiosensitive than the bone cells examined. The radioprotectant drugs amifostine and sodium selenite provided significant radioprotection to constituent bone cells while not protecting the tumor cells. Finally, amifostine and sodium selenite therapy provided an additional benefit beyond radioprotection by increasing cytotoxicity in nonirradiated and irradiated tumor cells. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1512–1519, 2008
Force sense deficits in functionally unstable ankles
Authors: Docherty Carrie L. , Arnold Brent L. 
Published: May 2008

AbstractThe purpose of this study was to determine whether participants with functional ankle instability have deficits in force sense reproduction compared to uninjured participants. Twenty participants with no history of injury and 20 with functional ankle instability volunteered for this investigation. Participants in the instability group had a history of at least one ankle sprain and frequent episodes of giving way. Ankle force sense testing was performed at 10, 20, and 30% of eversion maximal voluntary isometric contraction. Ten trials were performed at each force. Absolute and variable errors were then calculated. We observed significant (p < 0.05) main effects for group for absolute and variable errors. Force sense absolute error was significantly greater in the functionally unstable ankles (3.7 ± 2.2 N) compared to uninjured ankles (2.8 ± 1.1 N). Variable error was also significantly greater in the functionally unstable ankles (3.2 ± 1.8 N) than the uninjured ankles (2.4 ± 0.8 N). Functional ankle instability is associated with deficits in an individual's ability to accurately reproduce a given force. This deficit may impair an individual's ability to set appropriate muscle force levels to provide stability to the joint. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1489–1493, 2008
Effects of extrusion processing on nutrients in dry pet food
Authors: Tran Quang D , Hendriks Wouter H , van der Poel Antonius FB 
Published: May 2008

AbstractExtrusion cooking is commonly used to produce dry pet foods. As a process involving heat treatment, extrusion cooking can have both beneficial and detrimental effects on the nutritional quality of the product. Desirable effects of extrusion comprise increase in palatability, destruction of undesirable nutritionally active factors and improvement in digestibility and utilisation of proteins and starch. Undesirable effects of extrusion include reduction of protein quality due to e.g. the Maillard reaction, decrease in palatability and loss of heat‐labile vitamins. Effects of extrusion processing on the nutritional values of feeds for livestock have been well documented. Literature results concerning effects of extrusion on dry pet foods, however, are scarce. The present review discusses the results of studies investigating the impact of extrusion cooking on the nutritional quality of dry pet foods. Copyright © 2008 Society of Chemical Industry
On a multilaminate model for soil incorporating small strain stiffness
Authors: Scharinger Florian , Schweiger Helmut F. , Pande Gyan N. 
Published: May 2008

AbstractIn this paper a constitutive model for soils incorporating small strain stiffness formulated in the multilaminate framework is presented. In the multilaminate framework, the stress–strain behaviour of a material is obtained by integrating the mechanical response of an infinite number of randomly oriented planes passing through a material point. Such a procedure leads to a number of advantages in describing soil behaviour, the most significant being capture of initial and induced anisotropy due to plastic flow in a physically meaningful manner. In the past, many soil models of varying degree of refinement in the multilaminate framework have been presented by various authors. However, the issue of high initial soil stiffness in the range of very small strains and its degradation with straining, commonly referred to as ‘small strain stiffness’, has not been addressed within the multilaminate framework. In this paper, we adopt a micromechanics‐based approach to derive small strain elastic stiffness of the soil mass. Comparison of laboratory test data with results obtained from numerical simulations based on the proposed constitutive model incorporating small strain stiffness is performed to demonstrate its predictive capabilities. The model is implemented in a finite element code and numerical simulations of a deep excavation are presented with and without incorporation of small strain stiffness to demonstrate its importance in predicting profiles of deformation. Copyright © 2008 John Wiley & Sons, Ltd.
Longitudinal diffusion tensor imaging in a rat brain glioma model
Authors: Lope‐Piedrafita Silvia , Garcia‐Martin Maria L. , Galons Jean‐Philippe , Gillies Robert J. , Trouard Theodore P. 
Published: May 2008

AbstractIn order to investigate the properties of water motion within and around brain tumors as a function of tumor growth, longitudinal diffusion tensor imaging (DTI) was carried out in a rat brain glioma (C6) model. As tumors grew in size, significant anisotropy of water diffusion was seen both within and around the tumor. The tissue water surrounding the tumor exhibited high planar anisotropy, as opposed to the linear anisotropy normally seen in white matter, indicating that cells were experiencing stress in a direction normal to the tumor border. When tumors were sufficiently large, significant anisotropy was also seen within the tumor because of longer‐range organization of cancer cells within the tumor borders. These findings have important implications for diffusion‐weighted MRI experiments examining tumor growth and response to therapy. Copyright © 2008 John Wiley & Sons, Ltd.
A pH‐sensitive water‐soluble N‐carboxyethyl chitosan/poly(hydroxyethyl methacrylate) hydrogel as a potential drug sustained release matrix prepared by photopolymerization technique
Authors: Zhou Yingshan , Yang Dongzhi , Ma Guiping , Tan Hailin , Jin Yu , Nie Jun 
Published: May 2008

AbstractBiocompatible pH‐sensitive semi‐interpenetration polymeric network hydrogels (semi‐IPN) based on water‐soluble N‐carboxyethyl chitosan (CECS) and 2‐hydroxyethyl methacrylate (HEMA) were synthesized by the photopolymerization technique. pH‐sensitivity, cytotoxicity, morphology, mechanical property, and water state of hydrogel were investigated by a swelling test, methylthiazolydiphenyl‐tetrazolium bromide (MTT) assay, scanning electron microscopy (SEM), universal testing machine, and differential scanning calorimetry (DSC), respectively. The drug release studies were carried out using 5‐Flurouracil as the model drug. The results indicated that the hydrogels were sensitive to pH of the medium and its wet state had good mechanical properties. The results of cytotoxicity and prolonged drug release characteristics revealed the suitability of the hydrogels as drug delivery matrices. The release kinetics was evaluated by fitting the experimental data to standard release equations, and the best fit was obtained with the Higuchi model of the hydrogel. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis of functional polyethylene graft copolymers by nitroxide‐mediated living radical polymerization
Authors: Mohajery Shabnam , Rahmani Sohrab , Entezami Ali Akbar 
Published: May 2008

AbstractThis paper describes a new method to prepare graft copolymers, such as polyethylene‐g‐polystyrene (PE‐g‐PS), with a relatively well‐controlled reaction mechanism. The chemistry involves a transformation process from the metallocene copolymerization of ethylene and m,p‐methylstyrene (m,p‐MS) to nitroxide‐mediated “living” free radical polymerization (LRFP) of styrene. The metallocene catalysis produces ethylene‐co‐m,p‐methylstyrene (EMS) random copolymers. Next, 1‐hydroxyl‐2,2,6,6‐tetramethylpiperidine (HO‐TEMPO) was synthesized by the reduction of TEMPO with sodium ascorbate. The macroinitiator (EMS‐TEMPO) was synthesized with the bromination reaction of EMS, and the following nucleofilic reaction with this functional nitroxyl compound. The resulting macroinitiator (EMS‐TEMPO) for LRFP was then heated in the presence of styrene to form graft copolymer. DSC, 1H‐NMR, FTIR spectroscopy were employed to investigate the structure of the polymers. The results of Molau test showed that PE‐g‐PS could be a potential good compatilizer. Copyright © 2008 John Wiley & Sons, Ltd.
Acid‐catalysed hydrolysis of methoxy‐substituted trityl trifluoroethyl ethers: a kinetic and computational investigation of leaving group effects
Authors: López Moisés Canle , Demirtas Ibrahim , Maskill Howard , Mishima Masaaki 
Published: May 2008

AbstractTrityl trifluoroethyl (TFE) ether and its 4‐methoxy, 4,4′‐dimethoxy‐, and 4,4′,4″‐trimethoxy‐substituted analogues have been prepared; the dimethoxy and trimethoxy compounds undergo ready acid‐catalysed hydrolysis at constant ionic strength = 1 mol dm−3 at 25°C. The monomethoxy compound is less reactive and the parent trityl analogue showed minimal reactivity. Using presently reported and literature kinetics results with pKa values of protonated substrates, first‐order rate constants covering 12 orders of magnitude have been determined for heterolysis/dissociation of 11 protonated dimethoxytrityl derivatives DMTrYH+ where YH = H2O, CF3CH2OH, ArNH2 and RNH2. There is a good correlation between logarithms of these rate constants and the pKa values of the conjugate acids (Y) of the nucleofuges YH. Enthalpies and corresponding free energies at 25°C for the dissociation of the specifically solvated ions CH3 (YH = MeOH and CF3CH2OH, n = 1; H2O, n = 2; and NH3, n = 3) have been calculated at the B3LYP/6‐31+G* level. Corresponding gas phase calculations have also been carried out for Ph3C (YH = H2O, n = 2; MeOH, n = 1; CF3CH2OH, n = 1 and NH3, n = 3) and, in addition, structures for these solvated ions with (YH = H2O, MeOH and NH3) have been calculated. The specifically solvated ion Ph3CO(H)CH2CF3(H2O)+ does not correspond to a stable bonded species in the gas phase, which suggests that acid‐catalysed fragmentation of methoxy‐substituted analogues of Ph3COCH2CF3 in aqueous solution are concerted with proton transfer in which case the hydrolytic cleavage will be general acid catalysed. Copyright © 2008 John Wiley & Sons, Ltd.
Oesophageal cancer: caregiver mental health and strain
Authors: Donnelly M. , Anderson L.A. , Johnston B.T. , Watson R.G.P. , Murphy S.J. , Comber H. , McGuigan J. , Reynolds J.V. , Murray L.J. 
Published: May 2008

AbstractObjective: To investigate strain and mental health among family caregivers of oesophageal cancer patients and possible factors associated with caregiver mental health and strain.Methods: Patients with oesophageal adenocarcinoma in Ireland were recruited into the FINBAR study (the main aim of which was to investigate factors influencing the Barrett's adenocarcinoma relationship). Carers completed the 13‐item Caregiver Strain Index and the General Health Questionnaire‐30 (GHQ) in the context of a brief interview with trained research staff that was undertaken separately from the interview with each cancer patient.Results: Two hundred and twenty‐seven patients participated in the FINBAR study. A total of 39 patients did not have a family carer or the carer could not be identified. Fifty percent (94/188) of carers completed the questionnaires. Mean (SD) scores for strain (6.65, SD=3.63) and mental health status (10.21, SD=7.30) were high and 71% of carers scored >5 on the GHQ indicating psychological distress. There was a statistically significant positive relationship between level of strain experienced by caregivers and the severity of their mental health status and whether or not carers scored >5 on the GHQ. Relatives were 1.70 (95% CI 1.34–2.15) times more likely to be defined as high scorers with each unit increase in the CSI score.Conclusions: A significant proportion of caregivers experienced high levels of strain and psychological distress. There is a need to provide appropriate support and services targeted specifically at reducing the considerable strain of caring for patients with oesophageal cancer, particularly for carers of patients from lower socioeconomic groups. Copyright © 2008 John Wiley & Sons, Ltd.
The structure of the anti‐c‐myc antibody 9E10 Fab fragment/epitope peptide complex reveals a novel binding mode dominated by the heavy chain hypervariable loops
Authors: Krauß Norbert , Wessner Helga , Welfle Karin , Welfle Heinz , Scholz Christa , Seifert Martina , Zubow Kristina , Aÿ Jacqueline , Hahn Michael , Scheerer Patrick , Skerra Arne , Höhne Wolfgang 
Published: May 2008

AbstractThe X‐ray structure of the Fab fragment from the anti‐c‐myc antibody 9E10 was determined both as complex with its epitope peptide and for the free Fab. In the complex, two Fab molecules adopt an unusual head to head orientation with the epitope peptide arranged between them. In contrast, the free Fab forms a dimer with different orientation. In the Fab/peptide complex the peptide is bound to one of the two Fabs at the “back” of its extended CDR H3, in a cleft with CDR H1, thus forming a short, three‐stranded antiparallel β‐sheet. The N‐ and C‐terminal parts of the peptide are also in contact with the neighboring Fab fragment. Comparison between the CDR H3s of the two Fab molecules in complex with the peptide and those from the free Fab reveals high flexibility of this loop. This structural feature is in line with thermodynamic data from isothermic titration calorimetry. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Evidence for cross‐adaptation between s‐triazine herbicides resulting in reduced efficacy under field conditions
Authors: Krutz L Jason , Burke Ian C , Reddy Krishna N , Zablotowicz Robert M 
Published: May 2008

AbstractBACKGROUND: Enhanced atrazine degradation has been observed in agricultural soils from around the globe. Soils exhibiting enhanced atrazine degradation may be cross‐adapted with other s‐triazine herbicides, thereby reducing their control of sensitive weed species. The aims of this study were (1) to determine the field persistence of simazine in atrazine‐adapted and non‐adapted soils, (2) to compare mineralization of ring‐labeled 14C‐simazine and 14C‐atrazine between atrazine‐adapted and non‐adapted soils and (3) to evaluate prickly sida control with simazine in atrazine‐adapted and non‐adapted soils.RESULTS: Pooled over two pre‐emergent (PRE) application dates, simazine field persistence was 1.4‐fold lower in atrazine‐adapted than in non‐adapted soils. For both simazine and atrazine, the mineralization lag phase was 4.3‐fold shorter and the mineralization rate constant was 3.5‐fold higher in atrazine‐adapted than in non‐adapted soils. Collectively, the persistence and mineralization data confirm cross‐adaptation between these s‐triazine herbicides. In non‐adapted soils, simazine PRE at the 15 March and 17 April planting dates reduced prickly sida density at least 5.4‐fold compared with the no simazine PRE treatment. Conversely, in atrazine‐adapted soils, prickly sida densities were not statistically different between simazine PRE and no simazine PRE at either planting date, thereby indicating reduced simazine efficacy in atrazine‐adapted soils.CONCLUSIONS: Results demonstrate the potential for cross‐adaptation among s‐triazine herbicides and the subsequent reduction in the control of otherwise sensitive weed species. Copyright © 2008 Society of Chemical Industry
Colesevelam: new alternative or adjunctive treatment to statins
Authors: Chaplin Steve , Durrington Paul 
Published: May 2008

AbstractColesevelam (Cholestagel) is a new bile acid sequestrant for treating hypercholesterolaemia either alone or in combination with a statin. Here, Steve Chaplin describes the clinical trial data relating to its efficacy and safety, and Professor Durrington comments on its place in reducing raised cholesterol levels. Copyright © 2008 Wiley Interface Ltd
Determination of underivatized amino acid δ13C by liquid chromatography/isotope ratio mass spectrometry for nutritional studies: the effect of dietary non‐essential amino acid profile on the isotopic signature of individual amino acids in fish
Authors: McCullagh James , Gaye‐Siessegger Julia , Focken Ulfert 
Published: May 2008

AbstractThis study provides data for the effect of dietary non‐essential amino acid composition on the δ13C values of individual amino acids in rainbow trout (Oncorhynchus mykiss) using liquid chromatography coupled to isotope ratio mass spectrometry (LC/IRMS). In this experiment, trout were reared either on a control diet or on three experimental diets, differing in the composition of non‐essential/conditionally essential amino acids, for a period of 6 weeks. The control diet was a commercial trout starter feed with fish meal as the main protein source. The experimental diets contained no protein, only synthetic amino acids. Diet 1 resembled the composition of fish meal in both essential and non‐essential amino acids, Diet 2 had all essential amino acids, but cysteine, glycine, proline and tyrosine were replaced by the corresponding amounts of their precursors, and in Diet 3 all non‐essential amino acids were replaced by glutamate. LC/IRMS was used for the determination of δ13C values of individual amino acids from diets and tissues without derivatization. Diet affected the δ13C of individual amino acids in fish. For fish on Diets 1–3 amino acid δ13C values showed a similar trend: phenylalanine showed very little change from diet to body tissue. Arginine, lysine, tyrosine and proline showed strong depletion from diet to body tissue and glycine, alanine, aspartate and serine all showed variable but strong enrichment in 13C. Improvements are necessary before all amino acid δ13C values can be determined; however, this study demonstrates that measuring amino acid isotopic signatures by LC/IRMS is a promising new technique for nutritional physiologists. Copyright © 2008 John Wiley & Sons, Ltd.
The evolution of the mixing rate of a simple random walk on the giant component of a random graph
Authors: Fountoulakis N. , Reed B.A. 
Published: May 2008

AbstractIn this article we present a study of the mixing time of a random walk on the largest component of a supercritical random graph, also known as the giant component. We identify local obstructions that slow down the random walk, when the average degree d is at most O($ \sqrt{\ln n} $), proving that the mixing time in this case is Θ((n/d)2) asymptotically almost surely. As the average degree grows these become negligible and it is the diameter of the largest component that takes over, yielding mixing time Θ(n/d) a.a.s.. We proved these results during the 2003–04 academic year. Similar results but for constant d were later proved independently by Benjamini et al. in 3. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008
Modelling and control of variable‐speed multi‐pole permanent magnet synchronous generator wind turbine
Authors: Hansen Anca D. , Michalke Gabriele 
Published: May 2008

AbstractEmphasis of this article is on variable‐speed pitch‐controlled wind turbines with multi‐pole permanent magnet synchronous generator (PMSG) and on their extremely soft drive‐train shafts. A model and a control strategy for a full back‐to‐back converter wind turbine with multi‐pole PMSG are described. The model comprises submodels of the aerodynamic rotor, the drive‐train by a two‐mass model, the permanent magnet generator and the full‐scale converter system. The control strategy, which embraces both the wind turbine control itself and the control of the full‐scale converter, has tasks to control independently the active and reactive powers, to assist the power system and to ensure a stable normal operation of the wind turbine itself. A multi‐pole PMSG connected to the grid through a full‐scale converter has no inherent damping, and therefore, such configuration can become practically unstable, if no damping by means of external measures is applied. In this work, the frequency converter is designed to damp actively the drive‐train oscillations, thus ensuring stable operation. The dynamic performance of the presented model and control strategy is assessed and emphasized in normal operation conditions by means of simulations in the power system simulation tool DIgSILENT. Copyright © 2008 John Wiley & Sons, Ltd.
Wind turbine load level based on extrapolation and simplified methods
Authors: Freudenreich Kai , Argyriadis Kimon 
Published: May 2008

AbstractThis paper describes some effects on the load level of state‐of‐the‐art multi‐megawatt wind turbines introduced by the new edition of the standard IEC 61400‐1:2005 ‘Wind Turbines—Part 1: Design Requirements’. Compared to the previous edition, the extreme load determination has been modified by applying stochastic and statistical analyses. Within this paper, the effect on the extreme load level of wind turbines based on the newly introduced load extrapolation and extreme turbulence model (ETM) is demonstrated and occurring problems are discussed. Load simulations have been carried out for four state‐of‐the‐art multi‐megawatt wind turbines of different design concepts and from different manufacturers. The blade root bending moments and tip deflection have been determined by applying different extrapolation methods. Advantages and disadvantages of these methods and tail fittings are discussed and interpreted. The obtained loads are partly compared with long‐term simulations. The application of the ETM is demonstrated. The dependence of the load level on the turbulence intensity and control system, as well as the interaction with extrapolated loads, is discussed and limitations are outlined. The obtained load level is compared to the overall load level of the turbines according to the previous edition of the standard, IEC 61400‐1:1999. Based on extrapolated loads, simplified methods are described to obtain loads without load extrapolation to reduce the effort for simulation and post‐processing. Copyright © 2008 John Wiley & Sons, Ltd.