bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cylindrical meanderline radiofrequency coil for intravascular magnetic resonance studies of atherosclerotic plaque
Authors: Farrar Christian T. , Wedeen Van J. , Ackerman Jerome L. 
Published: December 2004

AbstractIn order to improve the performance of magnetic resonance imaging and spectroscopy of atherosclerotic plaque the potential use of novel radiofrequency coil structures with sensitive detection volumes tailored to the geometry of the arterial wall was investigated. It was found that a cylindrical meanderline (zig–zag) coil design provides a sensitive volume that is restricted to a cylindrical shell, thereby maximizing the filling factor and signal‐to‐noise ratio for plaques while reducing the intense blood signal. The cylindrical meanderline coil has the added advantages of an open interior, which allows for unimpeded blood flow during scanning, and the potential to be expanded against the walls of the artery, thereby stabilizing the coil against the pulsatile blood flow and minimizing motion artifacts. The performance of cylindrical meanderline coils with theoretical simulations of the electromagnetic fields as well as with experimental images of test objects (phantoms) and human endarterectomy surgical specimens is demonstrated. This radically new RF coil geometry offers the potential to improve the efficiency of MR data acquisition in medical applications in which curved surfaces or slabs contain the material of interest. Magn Reson Med 53:226–230, 2005. © 2004 Wiley‐Liss, Inc.
Preliminary investigation of respiratory self‐gating for free‐breathing segmented cine MRI
Authors: Larson Andrew C. , Kellman Peter , Arai Andrew , Hirsch Glenn A. , McVeigh Elliot , Li Debiao , Simonetti Orlando P. 
Published: December 2004

AbstractSegmented cine MRI generally requires breath‐holding, which can be problematic for many patients. Navigator echo techniques, particularly successful for free‐breathing coronary MRA, are incompatible with the acquisition strategies and SSFP pulse sequences commonly used for cine MRI. The purpose of this work is to introduce a new self‐gating technique deriving respiratory gating information directly from the raw imaging data acquired for segmented cine MRI. The respiratory self‐gating technique uses interleaved radial k‐space sampling to provide low‐resolution images in real time during the free‐breathing acquisition that are compared to target expiration images. Only the raw data‐producing images with high correlation to the target images are included in the final high‐resolution reconstruction. The self‐gating technique produced cine series with no significant differences in quantitative image sharpness to series produced using comparable breath‐held techniques. Because of the difficulties associated with breath‐holding, the respiratory self‐gating technique represents an important practical advance for cardiac MRI. Magn Reson Med 53:159–168, 2005. Published 2004 Wiley‐Liss, Inc.
Sodium magnetic resonance imaging of chemotherapeutic response in a rat glioma
Authors: Schepkin Victor D. , Ross Brian D. , Chenevert Thomas L. , Rehemtulla Alnawaz , Sharma Surabhi , Kumar Mahesh , Stojanovska Jadranka 
Published: December 2004

AbstractThis study investigates the comparative changes in the sodium MRI signal and proton diffusion following treatment using a 9L rat glioma model to develop markers of earliest response to cancer therapy. Sodium MRI and proton diffusion mapping were performed on untreated (n = 5) and chemotherapy 1,3‐bis(2‐chloroethyl)‐1‐nitrosourea‐treated rats (n = 5). Animals were scanned serially at 2‐ to 3‐day intervals for up to 30 days following therapy. The time course of Na concentration in a tumor showed a dramatic increase in the treated brain tumor compared to the untreated tumor, which correlates in time with an increase in tumor water diffusion. The largest posttreatment increase in sodium signal occurred 7–9 days following treatment and correlated to the period of the greatest chemotherapy‐induced cellular necrosis based on diffusion and histopathology. Both Na MRI and proton ADC mapping revealed early changes in tumor sodium content and cellularity. This study demonstrates the possibility of Na MRI to function as a biomarker for monitoring early tumor treatment and validates the use of monitoring changes in diffusion MRI values for assessing tumor cellularity. Magn Reson Med 53:85–92, 2005. © 2004 Wiley‐Liss, Inc.
A rigorous framework for diffusion tensor calculus
Authors: Batchelor P. G. , Moakher M. , Atkinson D. , Calamante F. , Connelly A. 
Published: December 2004

AbstractIn biological tissue, all eigenvalues of the diffusion tensor are assumed to be positive. Calculations in diffusion tensor MRI generally do not take into account this positive definiteness property of the tensor. Here, the space of positive definite tensors is used to construct a framework for diffusion tensor analysis. The method defines a distance function between a pair of tensors and the associated shortest path (geodesic) joining them. From this distance a method for computing tensor means, a new measure of anisotropy, and a method for tensor interpolation are derived. The method is illustrated using simulated and in vivo data. Magn Reson Med 53:221–225, 2005. © 2004 Wiley‐Liss, Inc.
Improved signal to noise in high‐resolution magic angle spinning total correlation spectroscopy studies of prostate tissues using rotor‐synchronized adiabatic pulses
Authors: Zektzer Andrew S. , Swanson Mark G. , Jarso Samson , Nelson Sarah J. , Vigneron Daniel B. , Kurhanewicz John 
Published: December 2004

AbstractA rotor‐synchronized WURST‐8 adiabatic pulse scheme was compared to the conventional MLEV‐17 hard pulse scheme for isotropic mixing in total correlation spectroscopy (TOCSY) studies of intact human prostate tissues under high‐resolution magic angle spinning (HR‐MAS) conditions. Both mixing schemes were extremely sensitive to the rotational resonance condition and dramatic reductions in signal to noise were observed when pulse durations deviated from 1/(spin rate). A significant increase in cross‐peak intensities was observed using rotor‐synchronized WURST‐8 adiabatic pulses versus those observed using the rotor‐synchronized MLEV‐17 hard pulse scheme in both solution and tissue. In tissue, absolute signal intensities ranged from 1.5× to 10.5× greater (average: 4.75×) when WURST‐8 was used in place of MLEV‐17. Moreover, the difference was so dramatic that several metabolite cross peaks observed using WURST‐8 pulses were not observed using MLEV‐17 pulses, including cross peaks corresponding to many of the choline‐ and ethanolamine‐containing metabolites. Due to the complex modulation of TOCSY cross peaks for multiply coupled spins and the shorter T2 relaxation times of tissue metabolites, maximum cross‐peak intensities occurred at shorter mixing times than predicted by theory. In summary, a WURST‐8 adiabatic mixing scheme produced significantly greater absolute cross‐peak signal intensities than MLEV‐17 hard pulse mixing, and maximum cross‐peak intensity versus mixing time must be established for specific spin systems and T2 relaxation times. Magn Reson Med 53:41–48, 2005. © 2004 Wiley‐Liss, Inc.
Super‐KdV equation: classical solutions and quantization
Authors: Kulish Petr P. , Zeitlin Anton M. 
Published: December 2004

AbstractThe supersymmetric extension of the Korteweg‐de Vries equation (super‐KdV) is considered. The direct and inverse scattering problems are studied and the N‐soliton solutions are obtained. The quantization of this dynamical system is introduced and possible application of the quantum inverse scattering method is also dicussed. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
KKT Systems in Operative Planning for Gas Distribution Networks
Authors: Ehrhardt Klaus , Steinbach Marc C. 
Published: December 2004

AbstractOperative planning in gas networks with prescribed binary decisions yields large scale nonlinear programs defined on graphs. We study the structure of the KKT systems arising in interior methods and present a customized direct solution algorithm. Computational results indicate that the algorithm is suitable for optimization in small and medium‐sized gas networks. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Topology Optimization for Continuum Structure with Decreasing Mass
Authors: Kutylowski R. 
Published: December 2004

AbstractThis paper deals with the proper distribution of material in a structure whose available mass decreases in the working time, i.e. part of the structure undergoes degradation and loses mass. This means, the other part of the structure must bear the load. Therefore the structure's mass should be redistributed to replace the degraded material. The present analysis is carried out for the so‐called smart structures which are able to shift their mass within a certain previously fixed area and this research falls within the analysing and decision system. Minimization of the mean compliance under the mass constraints with the artificial approach for updating the material properties is used [1], [2]. As a numerical realization of the problem FEM examples are presented. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photocuring kinetics of UV‐initiated free‐radical photopolymerizations with and without silica nanoparticles
Authors: Cho Jung‐Dae , Ju Hyoung‐Tae , Hong Jin‐Who 
Published: December 2004

AbstractWe used photodifferential scanning calorimetry to investigate the photocuring kinetics of UV‐initiated free‐radical photopolymerizations of acrylate systems with and without silica nanoparticles. Two kinetics parameters—the rate constant (k) and the order of the initiation reaction (m)—were determined for hybrid organic–inorganic nanocomposite systems containing different amounts of added silica nanoparticles (0–20 wt %) and at different isothermal temperatures (30–100 °C) using an autocatalytic kinetics model. The kinetic analysis revealed that the silica nanoparticles apparently accelerate the cure reaction and cure rate of the UV‐curable acrylate system, most probably due to the synergistic effect of silica nanoparticles during the photopolymerization process. However, a slight decrease in polymerization reactivity that occurred when the silica content increased beyond 15 wt % was attributed to aggregation between silica nanoparticles. We also observed that the addition of silica nanoparticles lowered the activation energy for the UV‐curable acrylate system, and that the collision factor for the system with silica nanoparticles was higher than that obtained for the system without silica nanoparticles, indicating that the reactivity of the former was greater than that of the latter. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 658–670, 2005
Radical polymerization behavior of a vinyl monomer bearing five‐membered cyclic carbonate structure and reactions of the obtained polymers with amines
Authors: Ochiai Bungo , Matsuki Masahiro , Nagai Daisuke , Miyagawa Toyoharu , Endo Takeshi 
Published: December 2004

AbstractRadical polymerization behavior of a vinyl substituted cyclic carbonate, 4‐phenyl‐5‐vinyl‐1,3‐dioxoran‐2‐one (1), is described. Radical polymerization of 1 proceeded through selective vinyl polymerization to produce polymers bearing carbonate groups in the side chain, in contrast to that of an oxirane analogue of 1, 1‐phenyl‐2‐vinyl oxirane that proceeds via the selective ring‐opening fashion. Although the homopolymerization of 1 produce polymers in relatively lower yield, copolymerizations effectively provided cyclic carbonate‐containing copolymers. Nucleophilic addition of primary amines to the resulting homopolymers and copolymers produced the corresponding multifunctional polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 584–592, 2005
M‐theory and gauged supergravities
Authors: Roest D. 
Published: December 2004

AbstractWe present a pedagogical discussion of the emergence of gauged supergravities from M‐theory. First, a review of maximal supergravity and its global symmetries and supersymmetric solutions is given. Next, different procedures of dimensional reduction are explained: reductions over a torus, a group manifold and a coset manifold and reductions with a twist. Emphasis is placed on the consistency of the truncations, the resulting gaugings and the possibility to generate field equations without an action. Using these techniques, we construct a number of gauged maximal supergravities in diverse dimensions with a string or M‐theory origin. One class consists of the CSO gaugings, which comprise the analytic continuations and group contractions of SO(n) gaugings. We construct the corresponding half‐supersymmetric domain walls and discuss their uplift to D‐ and M‐brane distributions. Furthermore, a number of gauged maximal supergravities are constructed that do not have an action.
Peptide models XLV: Conformational properties of N‐formyl‐L‐methioninamide and its relevance to methionine in proteins
Authors: Láng András , Csizmadia Imre G. , Perczel András 
Published: December 2004

AbstractThe conformational space of the most biologically significant backbone folds of a suitable methionine peptide model was explored by density functional computational method. Using a medium [6‐31G(d)] and a larger basis set [6‐311++G(2d,2p)], the systematic exploration of low‐energy backbone structures restricted for the “L‐region” in the Ramachandran map of N‐formyl‐L‐methioninamide results in conformers corresponding to the building units of an extended backbone structure (βL), an inverse γ‐turn (γL), or a right‐handed helical structure (αL). However, no poly‐proline II type (ϵL) fold was found, indicating that this conformer has no intrinsic stability, and highlighting the effect of molecular environment in stabilizing this backbone structure. This is in agreement with the abundance of the ϵL‐type backbone conformation of methionine found in proteins. Stability properties (ΔE) and distinct backbone–side‐chain interactions support the idea that specific intramolecular contacts are operative in the “selection” of the lowest energy conformers. Apart from the number of different folds, all stable conformers are within a 10 kcal.mol−1 energy range, indicating the highly flexible behavior of methionine. This conformational feature can be important in supporting catalytic processes, facilitating protein folding and dimerization via metal ion binding. In both of the biological examples discussed (HIV‐1 reverse transcriptase and PcoC copper‐resistant protein), the conformational properties of Met residues were found to be of key importance. Spatial proximity to other types of residues or the same type of residue seems to be crucial for the structural integrity of a protein, whether Met is buried or exposed. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Small‐world network approach to identify key residues in protein–protein interaction
Authors: del Sol Antonio , O'Meara Paul 
Published: December 2004

AbstractWe show that protein complexes can be represented as small‐world networks, exhibiting a relatively small number of highly central amino‐acid residues occurring frequently at protein–protein interfaces. We further base our analysis on a set of different biological examples of protein–protein interactions with experimentally validated hot spots, and show that 83% of these predicted highly central residues, which are conserved in sequence alignments and nonexposed to the solvent in the protein complex, correspond to or are in direct contact with an experimentally annotated hot spot. The remaining 17% show a general tendency to be close to an annotated hot spot. On the other hand, although there is no available experimental information on their contribution to the binding free energy, detailed analysis of their properties shows that they are good candidates for being hot spots. Thus, highly central residues have a clear tendency to be located in regions that include hot spots. We also show that some of the central residues in the protein complex interfaces are central in the monomeric structures before dimerization and that possible information relating to hot spots of binding free energy could be obtained from the unbound structures. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Reliability Engineering Practice in the Light Duty Dodge Ram Truck Chassis Program
Authors: Ling Jing , Hsieh Paul , Cowing Thomas 
Published: December 2004

AbstractIn this paper, we demonstrate how we set up and executed an integrated reliability engineering process with the engineering team in the Light Duty (LD) Dodge Ram (DR) Truck chassis program. Organizationally, the LD DR chassis team consists of core engineering groups and supporting representatives from other related disciplines. The reliability engineer is a member of the team and he is the reliability advocate and leader. The integrated reliability engineering process was customized and implemented in the LD DR chassis program. Many of the tools developed by the company corporate quality office, such as design failure modes and effect analysis (DFMEA), design verification plan and reporting (DVP&R), and finite element analysis (FEA), were used in supporting the reliability engineering process. An array of technical enablers such as Test Matrix and ReliUp were also developed for supporting the implementation of the reliability engineering process. In the execution, the reliability engineer led the engineering team to set up reliability targets, develop reliability work plans, facilitate up‐front design analysis, review and integrate reliability test planning. The reliability engineer also set up the failure reporting, analysis and corrective action system (FRACAS) and managed reliability growth with the team. From the implementation, we have learned several things: (1) an integrated engineering team is crucial in order to develop a product better, quicker and cheaper; (2) a good team leader is the key to product reliability; (3) a capable reliability engineer is the catalyst to a reliability engineering process; (4) the best culture in which to achieve reliability is the delicate balance between ‘inside‐out’ and ‘outside‐in’; and (5) achieving reliability is far more important than measuring reliability. Copyright © 2004 John Wiley & Sons, Ltd.
The Economic Design of ―x Charts: A Proactive Approach
Authors: Weheba Gamal S. , Nickerson David M. 
Published: December 2004

AbstractIt has long been recognized that poor quality can only result in higher costs. Yet, the idea of reducing cost through better quality is not fully realized. Current models for the economic design of control charts provide strategies to maintain existing quality levels. In this research, a comprehensive cost model is developed to incorporate two cost functions. A reactive function, which accounts for all quality related costs incurred while maintaining a stable level of the process, and a proactive function, which accounts for the cost of process improvement. Using incremental economics, the two cost functions are assembled to allow an evaluation of process improvement alternatives based on their economic worth. Procedures for obtaining economically optimum designs for controlling the process mean are developed and designed experiments are utilized to investigate model performance over a wide range of input parameters. The results indicate that the model is sensitive to changes in 13 parameters, especially when the magnitude of the process shift is small. Copyright © 2004 John Wiley & Sons, Ltd.
Waiting for Cardiac Surgery—Support Experienced by Next of Kin
Authors: Ivarsson Bodil , Sjöberg Trygve , Larsson Sylvia 
Published: December 2004

Background: Next of kin (NoK) play a crucial role for patients waiting for cardiac surgery.Aim: To describe experience of support, in the form of important events, by next of kin while their intimates were waiting for a heart operation.Methods: The design was qualitative and the “critical incident” technique was used. Incidents were collected via interviews with 23 next of kin to patients waiting for heart surgery and the informants were chosen by the patient themselves.Findings: In all, 224 important events, both positive and negative, were identified in the interviews and two main areas emerged in the analysis: internal factors and external factors. Positive internal factors were associated with finding strength, whereas negative factors were associated with uncomfortable feelings. Positive external factors were associated with participating in care and receiving attention, whereas negative factors were associated with dissatisfaction with the health-care organization and failing social network.Conclusion: This study shows that next of kin experienced positive support when they received attention and information and felt involvement in the care. An important implication for the health-care professionals and public authorities is the understanding of the experience of support expressed by next of kin, to provide them with optimal information and support.
A text book treatment of calculating returns on non‐traditional portfolios
Authors: Hancock G.D. 
Published: December 2004

AbstractThis paper addresses a gap in traditional portfolio literature by providing techniques for identifying returns on non‐traditional portfolios.Futures contracts require daily cash flows over the holding period; these cash flows determine the rate of return. The security deposit represents a tied investment since the funds are not available for other uses and do not earn a risk adjusted return. To initiate a short option or a short stock position also requires a cash outflow. The cash outflow or equity deposit effectively constitutes an investment since the trader postpones consumption in a risky medium that does not guarantee the return of the funds.By identifying the amount of the investment and rates of returns, it is possible to extend normative investment analysis to non‐traditional portfolio holdings. This paper introduces four propositions to aid in this process.
Conversing with the Dead: The Militia Movement and American History
Authors: MULLOY DARREN 
Published: December 2004

If one forgets the past, he will not be prepared for the future.The Militia of MontanaYES! TODAY JUST AS YESTERDAY.The Michigan MilitiaWhen the militia movement emerged in the United States during the mid 1990s its members were widely seen as simply the latest practitioners of what Richard Hofstadter famously called “the paranoid style in American politics.” There was much comfort to be had in this characterization. It fitted the militia movement into a long-standing model for understanding right-wing extremism in American life, one in which the principal characteristics of such extremism were readily understood: conspiratorial, Manichean, absolutist – if not apocalyptic – and, of course, paranoid. The problem with this approach, though, is that it tends to discourage any examination of mainstream culture's role in the creation or sustaining of those defined as extremists. It downplays the extent to which the pool of ideological resources employed by the extreme right exists not just on the margins of American life, but also in the very fabric of the American ideology. Little attempt is made to explore the extent to which the ideas and beliefs of these “extremists” are related to, and are drawn from, key periods in US history: from the American Revolution, the period of the constitutional settlement or the settling of the American West, for example. Yet such ideas and beliefs are absolutely central to how groups like the militias see themselves and the world around them.