bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gadobenate dimeglumine‐enhanced MR angiography: Diagnostic performance of four doses for detection and grading of carotid, renal, and aorto‐iliac stenoses compared to digital subtraction angiography
Authors: Schneider Günther , Ballarati Claudio , Grazioli Luigi , Manfredi Riccardo , Thurnher Siegfried , Kroencke Thomas J. , Taupitz Matthias , Merlino Biagio , Bonomo Lorenzo , Shen Ningyan , Pirovano Gianpaolo , Kirchin Miles A. , Spinazzi Alberto 
Published: September 2007

AbstractPurposeTo determine the diagnostic performance of contrast‐enhanced MR angiography (CE‐MRA) with four doses of gadobenate dimeglumine for detection of significant steno‐occlusive disease of the carotid, renal, and pelvic vasculature.Materials and MethodsEighty‐four patients with suspected disease of the renal (n = 16), pelvic (n = 41), or carotid (n = 27) arteries underwent CE‐MRA (3D‐spoiled gradient‐echo sequences) at 1.5T. CE‐MRA was performed with gadobenate dimeglumine at 0.025, 0.05, 0.1, or 0.2 mmol/kg (23, 24, 19, and 18 patients, respectively) administered at 2 mL/sec. Accuracy, sensitivity, specificity, and positive and negative predictive values (PPV and NPV, respectively) for detection of significant disease (>50% stenosis or occlusion for renal/pelvic arteries; >70% stenosis or occlusion for carotid arteries) was determined by three fully blinded, independent radiologists using conventional digital subtraction angiography (DSA) as reference standard. All comparisons were tested statistically (ANOVA, chi‐square, and Mantel–Haenszel tests as appropriate) and reader agreement (kappa) was assessed.ResultsValues for accuracy, sensitivity, specificity, PPV, and NPV on CE‐MRA were consistently higher for 0.1 mmol/kg gadobenate dimeglumine (accuracy = 95.2–97.3%, sensitivity = 84.2% (all readers), specificity = 96.9–99.2%, PPV = 80.0–94.1%, NPV = 97.6–97.7%). The greater accuracy of the 0.1 mmol/kg dose was significant (P < 0.01, all readers) compared to all other dose groups. Agreement between the three readers was good for all dose groups (kappa ≥0.58), with the highest percent agreement (85.7%) noted for the 0.1 mmol/kg dose.ConclusionSignificantly better diagnostic performance on CE‐MRA of the renal, pelvic, and carotid arteries is achieved with a gadobenate dimeglumine dose of 0.1 mmol/kg bodyweight. J. Magn. Reson. Imaging 2007;26:1020–1032. © 2007 Wiley‐Liss, Inc.
Improved dynamic susceptibility contrast (DSC)‐MR perfusion estimates by motion correction
Authors: Kosior Robert K. , Kosior Jayme C. , Frayne Richard 
Published: September 2007

AbstractPurposeTo investigate the effect of patient motion on quantitative cerebral blood flow (CBF) maps in ischemic stroke patients and to evaluate the efficacy of a motion‐correction scheme.Materials and MethodsPerfusion data from 25 ischemic stroke patients were selected for analysis. Two motion profiles were applied to a digital anthropomorphic brain phantom to estimate accuracy. CBF images were generated for motion‐corrupted and motion‐corrected data. To correct for motion, rigid‐body registration was performed. The realignment parameters and mean CBF in regions of interest were recorded.ResultsAll patient data with motion exhibited visibly reduced intervolume misalignment after motion correction. Improved flow delineation between different tissues and a more clearly defined ischemic lesion (IL) were achieved in the motion‐corrected CBF. A significant difference occurred in the IL (P < 0.05) for patients with severe motion with an average difference between corrupted and corrected data of 4.8 mL/minute/100 g. The phantom data supported the patient results with better CBF accuracy after motion correction and high registration accuracy (<1 mm translational and <1° rotational error).ConclusionMotion degrades flow differentiation between adjacent tissues in CBF maps and can cause ischemic severity to be underestimated. A registration motion correction scheme improves dynamic susceptibility contrast (DSC)‐MR perfusion estimates. J. Magn. Reson. Imaging 2007;26:1167–1172. © 2007 Wiley‐Liss, Inc.
An examination of the effects of organizational district and team contexts on team processes and performance: a meso‐mediational model
Authors: Mathieu John E. , Maynard M. Travis , Taylor Scott R. , Gilson Lucy L. , Ruddy Thomas M. 
Published: September 2007

AbstractWe examined the effects of organizational district and team contexts on team processes and performance in a longitudinal cross‐level design. As hypothesized, at the team‐level of analysis, interdependence related positively to team performance as partially mediated by processes. Moreover, a cross‐level mediational relationship was evident between the organizational district‐level openness climate and team performance as fully mediated by team processes. In contrast, organizational district‐level multi‐team coordination unexpectedly exhibited a direct cross‐level relationship with team performance. Multi‐team coordination also negatively interacted with team processes as related to team performance, in an exploratory analysis. Results are discussed in terms of the importance of considering both organizational‐district and team contexts as embedding conditions that influence team effectiveness. Copyright © 2007 John Wiley & Sons, Ltd.
Job design in temporal context: a career dynamics perspective
Authors: Fried Yitzhak , Grant Adam M. , Levi Ariel S. , Hadani Michael , Slowik Linda Haynes 
Published: September 2007

AbstractLeading theories of job design have neglected to incorporate the important context of time into their premises, hindering these theories' explanatory power and utility. We demonstrate how systematically incorporating the context of time, in relation to the specific example of career dynamics, will improve our understanding of job design. We discuss the contribution of time by examining how career dynamics may influence employees' reactions to stimulating jobs and their propensity to craft more stimulating jobs. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of baking method on some characteristics of starch in pound cake crumbs
Authors: Sánchez‐Pardo María E , Ortiz‐Moreno Alicia , Mora‐Escobedo Rosalva , Bello‐Pérez Arturo , Yee‐Madeira Hernani , Ramos‐López Gonzalo 
Published: September 2007

AbstractBACKGROUND: The effect of the baking process (microwave versus conventional oven) on some starch characteristics of pound cake was evaluated. Proximal chemical analysis, total resistant starch (RS), retrograded resistant starch (RS3), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD) were evaluated. Pound cake, one of the major products of Mexico's bread industry, was selected for analysis because the high moisture and fat content in the beaten dough might reduce the quality defects often associated with microwave baking.RESULTS: Crumbs from microwave‐baked pound cakes contained lower moisture than crumbs from conventionally baked pound cake. Lower RS was observed in fresh microwave‐baked than conventionally baked pound cake. RS3 increased significantly in conventionally baked products stored for 8 days at room temperature, whereas slightly lower changes in RS3 were observed in the microwaved product. DSC revealed less gelatinisation in microwaved pound cake which is related to limited water availability during the microwave heating process. The crystallinity peaks present in conventionally baked pound cake might be associated with RS3 content; the resistant retrograded starch formed during storage, is reflected in the XRD pattern.CONCLUSION: Microwave‐baked pound cake crumbs showed less gelatinisation than conventionally baked pound cake crumbs. Copyright © 2007 Society of Chemical Industry
Phosphorus status on Canadian organic farms
Authors: Martin Ralph C , Lynch Derek H , Frick Brenda , van Straaten Peter 
Published: September 2007

AbstractIn eastern North America, many conventional livestock farms, especially dairy farms with high inputs of feed and fertiliser have excess soil phosphorus levels and an annual phosphorus surplus. However, a Canadian dairy farm in transition to organic, without fertiliser inputs reduced its farm P surplus to a marginal level. On long‐term organic dairy farms in Ontario, most soils tested low to very low in available P as measured by a standard soil test. Canadian Prairie organic grain farms also consistently demonstrate deficiencies in available soil P. Organic producers have few viable alternatives for P management. Phosphate rock can be acceptable to organic standards (provided they are low in heavy metals, and not processed synthetically), but the P in these becomes available slowly, especially in high pH soils common on most organic farms in Canada. An alternative is to increase soil P availability. Enhanced microbial activity in organically managed soils may make P more available. Livestock manures are rich sources of available phosphorus, but a majority of organic farmers in Canada do not keep livestock. Off‐farm manure sources are subject to organic regulations and hauling costs, both of which may be prohibitive. Furthermore, manure from conventional farms in Canada may be contaminated by genetically modified material from corn and soybean feed. Additional research is required to improve short‐term availability of soil P and long‐term replacement. Copyright © 2007 Society of Chemical Industry
Proton‐Conducting Zirconium Pyrophosphate/Poly(2,5‐benzimidazole) Composite Membranes Prepared by a PPA Direct Casting Method
Authors: Kim Tae‐Ho , Lim Tae‐Wook , Park Yong‐Su , Shin Kyusoon , Lee Jong‐Chan 
Published: September 2007

AbstractZirconium pyrophosphate (ZPP)/poly(2,5‐benzimidazole) composites were prepared by polymerization of 3,4‐diaminobenzoic acid with zirconium hydrogen phosphate in polyphosphoric acid. The composite membranes for polymer electrolyte membranes were prepared by casting the polymerization solutions directly onto stainless steel plates. Membranes doped in 60 wt.‐% phosphoric acid solution had high proton conductivity values of more than 0.12 S · cm−1 (at 180 °C and 1% RH). Physical properties of the doped membranes, including the mechanical strength and dimensional stability, improved as ZPP content in the composites increased to 10–20 wt.‐%.magnified image
Random Networks, Graphs, and Matrices
Authors: Eichinger B. E. 
Published: September 2007

AbstractSummary: The theory of elasticity based on the distribution function of the gyration tensor is reviewed. It is shown that the James‐Guth potential for a network is a model potential of mean force, derivable in principle from the true many‐body potential for the elastic body. The determination of the modulus of elasticity is resolved in the calculation of the statistical mechanical average of the smallest, non‐zero, eigenvalue of the connectivity matrix that describes the network. The mathematical problem to determine the spectrum of eigenvalues of the random network can be couched in both the language of random graphs and of random matrices.
Toughness Properties of Lightly Crosslinked Epoxies Using Block Copolymers
Authors: Gerard Pierre , Boupat Nicolas Passade , Fine Thomas , Gervat Laurent , Pascault Jean‐Pierre 
Published: September 2007

AbstractSummary: In this work is discussed an alternative approach to the toughening of epoxy networks by the addition of acrylic block copolymers, composed of rigid and rubbery blocks. Once the reaction is completed, the initial self‐assembly of block copolymers in epoxy thermoset precursors produces rubbery domains: depending on the block copolymer structure and composition, these domains are of the micrometer or the nanometer size. Nanostructures are obtained when the rigid block is a random copolymer of methylmethacrylate and N,N‐dimethylacrylamide. The rubbery domains prevent rapid crack propagation and the highest toughness is obtained with filament‐like microparticles or wormlike micelles.
X‐ray Photon Correlation Spectroscopy of Dynamics in Thermosensitive Gels
Authors: Geissler Erik , Kosik Katalin , Fluerasu Andrei , Moussaïd Abdellatif , László Krisztina 
Published: September 2007

AbstractSummary: Temperature‐sensitive hydrogels undergo a volume phase transition (VPT) when heated above a critical temperature Tc. For the poly(N‐isopropyl acrylamide) (PNIPA)‐water system, Tc. = 34 °C. Below Tc the gels are transparent and highly swollen. On warming above Tc they promptly turn white and start to deswell. The rate of deswelling, however, can be orders of magnitude slower than that of swelling below Tc. The unstable intermediate structure above Tc, can retain the solvent and conserve the sample volume for may days, even with millimetre‐sized samples.Light scattering observations of the internal structure of these gels above Tc are precluded by their strong turbidity. Small angle X‐ray scattering measurements (SAXS), on the other hand, are less subject to multiple scattering as X‐rays penetrate more easily into the bulk material. Conventional (incoherent) SAXS observations reveal intense scattering from smooth internal water‐polymer interfaces with an estimated surface area of about 7 m2/g in the swollen gel. The dynamics in the off‐equilibrium high temperature state, investigated by X‐ray photon correlation spectroscopy (XPCS), displays a relaxation rate that is linearly proportional to the wavevector q, rather than to q2 as in diffusion processes. The physical origin of this relaxation is consistent with jamming, a phenomenon that is common in other disordered systems.
Polymethacrylate Networks as Substrates for Cell Culture
Authors: Sun Y. , Maughan J. , Haigh R. , Hopkins S. A. , Wyman P. , Johnson C. , Fullwood N. J. , Ebdon J. , MacNeil S. , Rimmer S. 
Published: September 2007

AbstractSummary: methacrylate networks have a long history of applications in medical technology and much is known of their non‐fouling properties. However, in recent times it has become clear that the swollen nature of these materials may provide some advantages if they are used as scaffolds in tissue engineering. In general however these hydrogels are resistant to protein adsorption and human cells do not easily adhere. In this work we provide an overview of several strategies that are designed to improve the cell‐adhesive properties of hydrogels while maintaining their useful properties, mainly ease of diffusion of nutrients and growth factors. We describe our early attempts at modifying hydrogels based on 2,3‐propandiol ‐1‐methacrylate, with either hydrophobic units or acid groups. Modification with lauryl methacrylate produced an improvement but acid modification failed to provide surfaces that were conducive to cell culture. Much better scaffolds were prepared by amination of epoxy functional 2,3‐propandiol‐1‐methacrylate networks. Optimized materials in this class were shown to be good substrates for the co‐culture of bovine keratocytes with human corneal epithelial cells. We also describe the synthesis and biological properties of methacrylate conetworks, which phase separate during synthesis to give porous amphiphilic materials. Optimization of these materials produces materials that perform as well as tissue culture plastic so that confluent sheets of human dermal fibroblasts can be produced using standard culture techniques.
Molecular Weight Influence on Gelatin Gels: Structure, Enthalpy and Rheology
Authors: Elharfaoui Nadia , Djabourov Madeleine , Babel Wilfried 
Published: September 2007

AbstractSummary: This paper deals with the gelation properties of gelatins with various molecular weights. The samples are 4 different extracts from limed bones. We investigated firstly the structural properties: the helix amounts by optical rotation measurements and the enthalpy of helix formation and melting, with the same thermal protocols and for various concentrations. Comparison between the two methods allowed deriving the enthalpy of helix‐coil transition and melting. Rheology was performed under the same conditions with a stress controlled rheometer working with a fixed, very small, strain during gel formation, maturation and melting. Correlation between all the measurements confirms the existence of the master curve for storage modulus versus gelatin concentration for all samples investigated.
Synthesis and Viscoelastic Properties of Hydrophobically Modified Hydrogels
Authors: Miquelard‐Garnier Guillaume , Creton Costantino , Hourdet Dominique 
Published: September 2007

AbstractSummary: We report the synthesis and characterization of a family of hydrophobically modified hydrogels designed to have an improved fracture resistance. A backbone of poly(acrylic acid) (PAA) was functionalized with double bonds and hydrophobic groups. The functionalized PAA was then crosslinked with a dithiol. The chemical structure of the gels was characterized with a combination of NMR, titration methods and rheological techniques. The crosslinked structure of the hydrogel was found to be dependent on the polymer concentration only, while the dissipative properties of the gel increased strongly at all frequencies, with the introduction of hydrophobic groups which formed reversible associations. We expect these viscoelastic hydrogels to display dramatically different properties from the unmodified hydrogels when stretched and fractured.
Parkinson's disease and resistive exercise: Rationale, review, and recommendations
Authors: Falvo Michael J. , Schilling Brian K. , Earhart Gammon M. 
Published: September 2007

AbstractIndividuals with Parkinson's disease (PD) are not only burdened with disease‐specific symptoms (i.e., bradykinesia, rigidity, and tremor), but are also confronted with age‐associated progressive loss of physical function, perhaps to a greater extent than neurologically normal adults. Suggestions for the inclusion of resistive exercise into treatment to attenuate these symptoms were made over 10 years ago, yet very few well controlled investigations are available. The objective of this review is to establish a clear rationale for the efficacy of resistance training in individuals with PD. Specifically, we highlight musculoskeletal weakness and its relationship to function as well as potential training‐induced adaptive alterations in the neuromuscular system. We also review the few resistance training interventions currently available, but limit this review to those investigations that provide a quantitative exercise prescription. Finally, we recommend future lines of inquiry warranting further attention and call to question the rationale behind current exercise prescriptions. The absence of reports contraindicating resistive exercise, the potential for positive adaptation, and the noted benefits of resistance training in other populations may provide support for its inclusion into a treatment approach to PD. © 2007 Movement Disorder Society
Delayed‐onset dystonia due to perinatal asphyxia: A prospective study
Authors: Nataša Cerovac  , Petrović Igor , Klein Christine , Kostić Vladimir S. 
Published: September 2007

AbstractThe objective of this work was to establish the existence and incidence of possible delayed‐onset dystonia in a cohort of infants with diagnosed perinatal asphyxial hypoxic‐ischemic encephalopathy (HIE). This prospective study comprised 103 survivors of perinatal asphyxial HIE, who were regularly followed and neurologically examined in the course of 7 to 13 years after birth (median 10 years). Neurological outcome at the end of the follow‐up period was normal in 87 (84.5%) patients, while in 7 (6.8%) only mild neurological signs were detected (behavioral disturbances in 3, clumsiness in 2, and hypotonia in 1 patient). Severe cerebral palsy was diagnosed in nine patients (8.7%). Only one patient was diagnosed with possible delayed‐onset segmental dystonia. At the age of 4 years he developed cervical dystonia with spread to one arm in the course of 1.5 years (segmental dystonia) and then stabilized. Other known causes of dystonia, including a DYT1 mutation, were excluded. Our preliminary data suggest that over the course of at least 7 years after birth, approximately 1% of infants who survived perinatal asphyxial HIE would develop delayed‐onset dystonia. © 2007 Movement Disorder Society
Switching costs, dynamic uncertainty, and buyer–seller relationships
Authors: Murthy Nagesh N. , Shrikhande Milind , Subramanian Ajay 
Published: September 2007

AbstractWe analyze strategic relationships between buyers and sellers in markets with switching costs and dynamic uncertainty by investigating the scenario wherein a representative buyer trades with two foreign sellers located in the same foreign country. We show that, under exchange rate uncertainty, switching costs may lead to switching equilibria where both sellers co‐exist in the market with the buyer, or no‐switching equilibria where either seller captures the market. The presence of exchange rate uncertainty facilitates competition by allowing the sellers to co‐exist in the market with the buyer. However, if the level of uncertainty is beyond a threshold, the only viable equilibria are those where one of the sellers captures the market. Further, depending on the level of exchange rate uncertainty and the sellers' variable costs, switching costs may either raise or lower the level of prices in long‐term contracts between the buyer and the sellers. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007
Synthesis of an α‐amino nitrile and a bis α‐amino nitrile derivative of thiadiazole: reaction mechanism
Authors: Mirífico María Virginia , Caram José Alberto , Piro Oscar Enrique , Vasini Enrique Julio 
Published: September 2007

AbstractThe first nucleophilic addition of an inorganic nucleophile (cyanide) to the activated, rigid, α‐diazomethine groups of a 1,2,5‐thiadiazole 1,1‐dioxide is reported here. An α‐amino nitrile and a bis α‐amino nitrile derivatives were obtained in good yields (62 and 98%, respectively) and characterized by spectroscopic, analytical, and single crystal X‐ray diffraction techniques. The course of the reaction, followed by cyclic voltammetry (CV), showed that cyanide adds to only one of the two CN double bonds of the thiadiazole, forming an anion from which an N‐methyl derivative was obtained. Adequate concentrations of cyanide and methyl iodide (MeI) produced directly the bis α‐amino nitrile derivative. Copyright © 2007 John Wiley & Sons, Ltd.
A diverse view of protein dynamics from NMR studies of HIV‐1 protease flaps
Authors: Ishima Rieko , Louis John M. 
Published: September 2007

AbstractInternal motion in proteins fulfills a multitude of roles in biological processes. NMR spectroscopy has been applied to elucidate protein dynamics at the atomic level, albeit at a low resolution, and is often complemented by molecular dynamics simulation. However, it is critical to justify the consistency between simulation results and conclusions often drawn from multiple experiments in which uncertainties arising from assumed motional models may not be explicitly evaluated. To understand the role of the flaps of HIV‐1 protease dimer in substrate recognition and protease function, many molecular dynamics simulations have been performed. The simulations have resulted in various proposed models of the flap dynamics, some of which are more consistent than others with our working model previously derived from experiments. However, using the working model to discriminate among the simulation results is not straightforward because the working model was derived from a combination of NMR experiments and crystal structure data. In this study, we use the NMR chemical shifts and relaxation data of the protease “monomer” rather than structural data to narrow down the possible conformations of the flaps of the “dimer”. For the first time, we show that the tips of the flaps in the unliganded protease dimer interact with each other in solution. Accordingly, we discuss the consistency of the simulations with the model derived from all experimental data. Proteins 2008. © 2007 Wiley‐Liss, Inc.