bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing atrophy of the major white matter fiber bundles of the brain from diffusion tensor MRI data
Authors: Pagani Elisabetta , Horsfield Mark A. , Rocca Maria A. , Filippi Massimo 
Published: August 2007

AbstractBrain atrophy is a typical feature of many neurological conditions. Therefore, quantitative evaluation and spatial characterization of atrophy are potentially useful for monitoring the evolution of central nervous system (CNS) disorders. In this study, a method for measuring atrophy of the major white matter (WM) fiber bundles in the brain using diffusion tensor (DT) MRI data is developed. To this end, an atlas was created from sets of diffusion anisotropy images from normal subjects, and the deformations necessary to match single subject anisotropy images to this atlas were then computed. Because diffusion anisotropy images were used, this approach should be sensitive to fiber bundle volume changes in the same way that using T1‐weighted images allows gray matter volume changes to be measured. The Jacobian determinant of the deformation field for each subject was then used as a measure of contraction or expansion of the tissue at each image voxel. An overview of the nonlinear registration problem is given; then an optimization of the parameters for the chosen algorithm is performed and the method for producing the atlas is described. The effectiveness of the method was then tested on data from five patients with multiple sclerosis (MS) and two patients with amyotrophic lateral sclerosis (ALS). Magn Reson Med 58:527–534, 2007. © 2007 Wiley‐Liss, Inc.
Feasibility of multiple‐mouse dynamic contrast‐enhanced MRI
Authors: Ramirez Marc S. , Ragan Dustin K. , Kundra Vikas , Bankson James A. 
Published: August 2007

AbstractDynamic contrast‐enhanced (DCE‐) MRI is often used to evaluate the response to experimental antiangiogenic therapies in small animal models of cancer. Unfortunately, DCE‐MRI studies often require a substantial investment of both time and money to achieve the desired level of statistical significance. Multiple‐mouse MRI has previously been used to improve imaging efficiency, but its feasibility for DCE‐MRI has not been investigated. The purpose of this work was to determine if multiple‐mouse DCE‐MRI is feasible when using gadolinium‐based contrast agents with a low molecular weight. A population of tumor‐bearing mice was scanned using two four‐element arrays and a single‐coil configuration on a 4.7T, 40 cm bore Bruker Biospec MRI scanner. Pharmacokinetic parameters were calculated and compared to determine if a significant difference between methodologies existed. With both four‐animal imaging configurations, animal throughput accelerations of just less than three were achieved and quantitative data were not significantly different than from single‐animal acquisitions. Magn Reson Med 58:610–615, 2007. © 2007 Wiley‐Liss, Inc.
Quantifying the blood oxygenation level dependent effect in cerebral blood volume–weighted functional MRI at 9.4T
Authors: Lu Hanbing , Scholl Clara A. , Zuo Yantao , Stein Elliot A. , Yang Yihong 
Published: August 2007

AbstractIn cerebral blood volume (CBV)‐weighted functional MRI (fMRI) employing superparamagnetic contrast agent, iron dose and blood oxygenation level dependent (BOLD) contamination are two important issues for experimental design and CBV quantification. Both BOLD and CBV‐weighted fMRI are based upon the susceptibility effect, to which spin‐echo and gradient‐echo sequences have different sensitivities. In the present study, CBV‐weighted fMRI was conducted using spin‐echo and gradient‐echo sequences at 9.4T by systematically changing the doses of contrast agent. Results suggest that BOLD contamination is a significant component in CBV‐weighted fMRI at high field, particularly when relatively low dose of contrast agent is administered. A mathematical model was developed to quantify the extravascular (EV) BOLD effect. With a TE of 35 ms, the EV BOLD effect was estimated to account for 76 ± 12% of the observed spin‐echo fMRI signal at 9.4T. These data suggest that correcting BOLD effect may be necessary for accurately quantifying activation‐induced CBV changes at high field. Magn Reson Med 58:616–621, 2007. © 2007 Wiley‐Liss, Inc.
Unique patterns of diffusion directionality in rat brain tumors revealed by high‐resolution diffusion tensor MRI
Authors: Zhang Jiangyang , van Zijl Peter C.M. , Laterra John , Salhotra Amandeep , Lal Bachchu , Mori Susumu , Zhou Jinyuan 
Published: August 2007

AbstractDiffusion tensor imaging (DTI) is a new technique that uses the microscopic motion of water molecules to probe tissue 3D microstructures. In this study, high‐resolution DTI was performed on rats bearing intracranial 9L gliosarcoma, F98 glioma, and human glioblastoma. It was found that the tumors consisted of central zones with low diffusion anisotropy and peripheral structures (rim) with high diffusion anisotropy. In the rims, water diffusion directionality formed a circular pattern for the 9L and F98 tumors, and a radial pattern for the human glioblastoma xenografts. These well‐organized diffusion patterns appeared at an early stage postimplantation and continued to exist with tumor growth in all three models. High‐resolution ex vivo imaging and histology confirmed the in vivo findings. These distinct patterns, undetectable with conventional MRI, may reflect tumor organization and growth patterns at the cellular level. Magn Reson Med 58:454–462, 2007. © 2007 Wiley‐Liss, Inc.
Severe Guillain–Barré syndrome associated with chromosome 17p11.2‐12 duplication
Authors: Münch Christoph , Epplen Jörg T. , Meins Moritz , Meyer Robert , Weber Jörg R. , Meyer Thomas 
Published: August 2007

AbstractWe report a patient with Guillain–Barré syndrome (GBS), characterized by severe tetraparesis, bulbar syndrome, and ophthalmoparesis. The nadir was reached within 1 day, followed by respiratory insufficiency requiring mechanical ventilation. Molecular analysis revealed a duplication at chromosome 17p11.2‐12, which is a known genetic cause of Charcot–Marie–Tooth disease type 1A (CMT1A). We suggest that this genotype may comprise a previously unrecognized genetic risk factor for GBS. Muscle Nerve, 2007
Diagnostic validity of epidermal nerve fiber densities in painful sensory neuropathies
Authors: Vlčková‐Moravcová Eva , Bednařík Josef , Dušek Ladislav , Toyka Klaus V. , Sommer Claudia 
Published: August 2007

AbstractIn this prospective study, intraepidermal nerve fiber densities (IENFD) and subepidermal nerve plexus densities (SENPD) were quantified by immunostaining in skin punch biopsies from the distal calf in 99 patients with clinical symptoms of painful sensory neuropathy and from 37 age‐matched healthy volunteers. The clinical diagnosis was based on history and abnormal thermal thresholds on quantitative sensory testing (QST). In patients with neuropathy, IENFD and SENPD were reduced to about 50% of controls. Elevated warm detection thresholds on QST correlated with IENFD but not with SENPD. Using receiver‐operating characteristic (ROC) curve analysis of IENFD values, the diagnostic sensitivity for detecting neuropathy was 0.80 and the specificity 0.82. For SENPD, sensitivity was 0.81 and specificity 0.88. With ROC analysis of both IENFD and SENPD together, the diagnostic sensitivity was further improved to 0.92. The combined examination of IENFD and SENPD is a highly sensitive and specific diagnostic tool in patients suspected to suffer from painful sensory neuropathies but with normal values on clinical neurophysiological studies. Muscle Nerve, 2007
An Italian family with inclusion‐body myopathy and frontotemporal dementia due to mutation in the VCP gene
Authors: Gidaro Teresa , Modoni Anna , Sabatelli Mario , Tasca Giorgio , Broccolini Aldobrando , Mirabella Massimiliano 
Published: August 2007

AbstractMutations of the valosin‐containing protein gene (VCP) are responsible for autosomal‐dominant hereditary inclusion‐body myopathy associated with frontotemporal dementia and Paget's disease of bone. We identified the p.R155C missense mutation in the VCP gene segregating in an Italian family with three affected siblings, two of whom had a progressive myopathy associated with dementia, whereas one exhibited a progressive myopathy and preclinical signs of Paget's disease of bone. Our study demonstrates that VCP mutations are found in patients of Italian background and may lead to a variable clinical phenotype even within the same kinship. Muscle Nerve, 2007
Decrease in peripheral muscle strength and ankle dorsiflexion as long‐term side effects of treatment for childhood cancer
Authors: Hartman Annelies , van den Bos Cor , Stijnen Theo , Pieters Rob 
Published: August 2007

AbstractBackgroundThis study investigated muscle strength, passive ankle dorsiflexion, and their association with motor performance in children after treatment for acute lymphoblastic leukemia, Wilms tumor, B‐non‐Hodgkin lymphoma, and malignant mesenchymal tumors.ProcedureMuscle strength was assessed with a hand‐held dynamometer and ankle dorsiflexion with a goniometer in 92 and 64 survivors, respectively. Motor performance was measured with the Movement Assessment Battery for Children (movement‐ABC). Age at testing: 6.1–12.9 years. Mean time since completing treatment: 3.3 years. Results were compared to 155 healthy controls.ResultsMuscle strength of the survivors was reduced in ankle dorsiflexors on both sides (P < 0.001), wrist dorsiflexors on the non‐dominant side (P < 0.001), and pinch grip on the non‐dominant (P = 0.001) and dominant side (P = 0.01). Passive ankle dorsiflexion of the survivors was significantly less on both sides (P < 0.01). Movement‐ABC percentile score was affected by pinch grip strength on the non‐dominant (P < 0.004), and dominant side (P = 0.024) but not by strength of other muscle groups or by passive ankle dorsiflexion.ConclusionPeripheral muscle strength and ankle dorsiflexion are reduced in the long‐term in children treated for cancer with chemotherapy. However, neither decreased muscle strength nor reduced ankle dorsiflexion could completely explain reduced scores on the movement‐ABC. Pediatr Blood Cancer. Pediatr Blood Cancer 2008;50:833–837. © 2007 Wiley‐Liss, Inc.
Liquid crystalline epoxides with long lateral substituents: Mechanical and thermal properties
Authors: Zheng Yiquan , Lu Mangeng , Ren Shaoping , Liang Liyan , Lan Yanxun 
Published: August 2007

AbstractIn this work, mechanical and thermal properties of liquid crystalline epoxides (LCEs) with long lateral substituents from 4 to 12 carbon atoms cured with diaminodiphenylmethane were evaluated and analyzed by dynamic mechanical analysis, tensile tests, scanning electron micrographs (SEM), and thermo‐gravimetrical analysis. The experimental results indicated that the Young's modulus and α, β transitions in crosslinked networks are associated with the length of lateral substituents. The plastic deformation in fracture surfaces was observed by SEM. Thermal stability, water and solvent absorption of cured networks was dependent on the length of lateral substituents. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2835–2841, 2007
Breadth of glass transition temperature in styrene/acrylic acid block, random, and gradient copolymers: Unusual sequence distribution effects
Authors: Wong Christopher L. H. , Kim Jungki , Torkelson John M. 
Published: August 2007

AbstractBlock, random, and gradient copolymers of styrene (S) and acrylic acid (AA) are synthesized by conventional or controlled radical polymerization, and their glass transition temperature (Tg) behaviors are compared. The location and breadth of the Tgs are determined using derivatives of differential scanning calorimetry heating curves. Each S/AA random copolymer exhibits one narrow Tg, consistent with a single phase of limited compositional nanoheterogeneity. Block copolymers exhibit two narrow Tgs originating from nanophase separation into ordered domains with nearly pure S or nearly pure AA repeat units. Each gradient copolymer exhibits a Tg response with a ∼50–56 °C breadth that extends beyond the upper Tg of the block copolymers. For copolymers of similar composition, the maximum value in the gradient copolymer Tg response is consistent with that of a random copolymer, which has an enhanced Tg relative to poly(acrylic acid) due to more effective hydrogen bonding when AA units are separated along the chain backbone by S units. These results indicate that gradient copolymers with ordered nanostructures can be rationally designed, which exhibit broad glass transitions that extend to higher temperature than the Tgs observed with block copolymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2842–2849, 2007
Unique structural characteristics of nematic ordered cellulose—Stability in water and its facile transformation
Authors: Togawa Eiji , Kondo Tetsuo 
Published: August 2007

AbstractNematic Ordered Cellulose (NOC) film that exhibits a noncrystalline yet highly ordered form was prepared by stretching a water‐swollen cellulose gel obtained in a unique manner with coagulation of cellulose molecules dissolved in the N,N‐dimethylacetamide/LiCl solvent system. In this article, structural characteristics of this unique film were investigated. Orientation of the molecular chains in the noncrystalline regions across the entire film were stable after immersing in water at room temperature, though conventional amorphous cellulose regions are in any forms believed fairly to be recrystallized under a humid atmosphere. Even 30 days after immersing in water at 50 °C, neither crystallization nor disordering of the chains occurred in the NOC film. On the contrary, the film was capable of being transformed into films composed of cellulose polymorphs domains where the molecular orientation was still maintained as the initial film under various mild conditions that both cotton and cellophane did not show any changes on their structure. These contradictory properties of the NOC film proved to be dependent on its unique supermolecular structure. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2850–2859, 2007
Improvement of energetic efficiency for homoepitaxial diamond growth in a H2/CH4 pulsed discharge
Authors: Brinza O. , Achard J. , Silva F. , Duten X. , Michau A. , Hassouni K. , Gicquel A. 
Published: August 2007

AbstractThe use of pulsed discharges for diamond deposition has been demonstrated to ensure a better control of heat transfer from the plasma to the walls in microwave plasma reactors. It also favours the production of CH3 species while keeping constant or higher the H‐atom density. Higher growth rates can then be obtained. In this paper is reported an increase of the growth rate by 25% while decreasing the input microwave mean power by 15%. These results are discussed in terms of atomic hydrogen and methyl radicals densities calculated with a unstationary 1‐D axial plasma model. The results show in particular that the gas temperature, which directly controls atomic hydrogen production, needs a ton of around 8 ms to reach the steady state, and that 50% of atomic hydrogen is lost by recombination after a toff of 2 ms. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Versatile properties of nanocrystalline diamond films deposited in Ar/H2/CH4 microwave discharges as a function of process parameters
Authors: Monéger D. , Bénédic F. , Sarry F. , Renard P. , Azouani R. , Elmazria O. , Silva F. , Gicquel A. 
Published: August 2007

AbstractIn this paper, we discuss on the versatility of nanocrystalline diamond (NCD) film properties as a function of the process parameters aiming to properly fulfil the requirements for various applications. NCD films are achieved in Ar/H2/CH4 microwave discharges. Their characteristics are changed by varying the depo‐sition parameters: pulsed and continuous discharges, hydrogen concentration, microwave power, surface temperature, and N2 ratio in the gas mixture as impurity. SEM, Raman spectroscopy, X‐ray diffraction, AFM and electrical measurements (Arrhenius diagrams) are performed in order to assess the film properties. The microstructure and phase purity, that mainly determine the surface roughness, electrical resisti‐vity, and growth rate, critical parameters for industrial applications such as mechanics and electronics, are particularly examined. The results point out the flexibility of the microwave plasma assisted process, suitable to straightforwardly control and adapt NCD film properties to the expected applications. Thus, a transition from nanocrystalline to microcrystalline structures is easily obtained with different amounts of non‐diamond phases, leading to surface roughness increasing from 20 nm to 80 nm and keeping appreciable growth rates around 1 µm h–1. The most striking results concern the wide range of the film transversal resistance values measured at room temperature, evolving from 400 Ω for graphite‐like NCD film to 3 × 1012 Ω for microcrystalline diamond. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigating large vacancy clusters in type IIa diamond with electron energy loss spectroscopy (EELS)
Authors: Barnes R. , Bangert U. , Scott A. 
Published: August 2007

AbstractThe origin of colour in brown diamonds has attracted much attention in recent years, and resulted in many attempts to characterise the responsible defect. These years of focused study have only ruled out possible solutions, including the popular hypothesis of dislocation states (B. Willems, PhD Thesis, University of Antwerp (2006) [1]). Most recently, positron annihilation studies have verified the existence of large clusters of vacancies in type IIa brown diamond (J. M. Mäki et al., presented at SBDDX (2004) [2]) that are significantly higher in concentration than in the corresponding treated colourless diamond. Also, theoretical calculations of large clusters of vacancies show {111} π‐bonded surfaces cause the same broad featureless optical absorption as brown diamond (L. Hounsome et al., phys. stat. sol. (a) 202, 2182 (2005) [3]). This bonding is also shown to produce intensity at 5–7 eV in low loss electron energy loss spectroscopy (EELS). Comparing EELS analysis of brown and colourless diamond reveals a relative increase in intensity at 5–7 eV in the brown diamond. Using EELS with energy resolution between 0.25 and 0.4 eV (U. Bangert et al., Ultramicroscopy 104, 46 (2003) [4]) on the NW‐STEM and SuperSTEM, π‐bonding intensity is verified to be present as a bulk feature in brown diamond. This π‐bonding is found across all regions of brown diamond regardless of position relative to dislocations. On closer inspection this π‐bonding intensity shows variations on a scale that could be related to vacancy clusters or several clusters, however more investigation is needed. In colourless diamond, any intensity in the π‐bonding region can be attributed to surface contamination. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cathodoluminescence as a tool to determine the phosphorus concentration in diamond
Authors: Barjon J. , Pinault M.‐A. , Kociniewski T. , Jomard F. , Chevallier J. 
Published: August 2007

AbstractIn n‐type diamond doped with phosphorus, exciton properties have been investigated by cathodoluminescence as a function of the phosphorus concentration. A series of homoepitaxial diamond layers were grown by microwave plasma‐assisted chemical vapor deposition and doped with a liquid organic precursor of phosphorus (tertiarybutylphosphine). Their phosphorus concentration ranges from 5.2 × 1016 cm–3 to 3.3 × 1018 cm–3 as measured by secondary ion mass spectrometry. It is shown that the ratio between the luminescence intensities of the neutral phosphorus‐bound exciton and the free exciton recombinations follows the donor concentration. A calibration graph is presented to determine the phosphorus contents in diamond with cathodoluminescence spectroscopy at 102 K. The influence of electrical compensation on the optical spectra is discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diamond ultramicroelectrodes
Authors: Foord John S. , Hu Jingping , Holt Katherine B. 
Published: August 2007

AbstractUltramicroelectrode (UME) tips from conductive diamond were fabricated by hot filament chemical vapour deposition. By changing growth conditions, it was possible to fabricate tips with very smooth nanocrystalline coatings, or relatively rough microcrystalline deposits. Cyclic voltammetry data in ferrocene methanol solution was recorded to characterise the two types of diamond. Nanocrystalline diamond displayed inferior behaviour, both in terms of the potential window, and the background current. Two types of insulation method were studied to complete the microelectrode fabrication process. Nail varnish was found to be easiest to apply and produce the best results. Fast set epoxy produced electrodes with inferior voltammetric characteristics. Electrochemical approach curves were measured under differing conditions for the electrodes studied. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of the CVD process sequences for an improved control of the Bias Enhanced Nucleation step on silicon
Authors: Saada S. , Arnault J. C. , Tranchant N. , Bonnauron M. , Bergonzo P. 
Published: August 2007

AbstractDiamond epitaxy is of great interest for electronic applications. Most of the time, heteroepitaxial diamond films have been obtained using the Bias Enhanced Nucleation (BEN) step. To investigate the transition between the first CVD plasma exposure and the BEN steps, we studied the residence time distribution (RTD) to monitor the methane concentration in the gas mixture. We showed that the stabilisation time of the methane concentration is not negligible when compared to the biasing duration currently used to obtain high nucleation density and induces effects on the current variation during the first stages of nucleation. We proposed a modelisation of the CVD reactor from experimental data to optimise and reduce this stabilisation time. Then, we showed that the nucleation phenomena are strongly dependent of the used protocol. To conclude, we propose a new approach for an improved control of the Bias Enhanced Nucleation parameters towards a greater reproducibility. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability of H‐terminated BDD electrodes: an insight into the influence of the surface preparation
Authors: Vanhove E. , de Sanoit J. , Arnault J. C. , Saada S. , Mer C. , Mailley P. , Bergonzo P. , Nesladek M. 
Published: August 2007

AbstractEIS, CV and XPS experiments were carried out to address the evolution of H‐terminated BDD electrochemical properties under intensive use and air aging. A drastic drop of apparent electron transfer rate k0′ was thus recorded using Fe(CN6)3–/4– as the redox mediator by identifying components of the Randles equivalent circuit. Excellent agreement was observed between theoretical and experimental curves. The feasibility of recovering and stabilizing high reactivity and reversible behaviour by applying a suitable electrochemical post treatment was then demonstrated. Such a treatment was developed empirically and seemed to significantly improve the electrode performances. On the basis of our results, we claim that the electrochemical evolutions observed are strongly linked to chemical termination modifications and partial inactivation of the electrode surface. Further research on the mechanisms that govern electron mediation at the diamond surface would be of high interest for better control of diamond electrode stability and reactivity towards their applications for bio‐electronic devices. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)