bluuebunny/crossref_metadata_2025_split huggingface dataset:
Major life events and risk of Parkinson's disease
Authors: Rod Naja Hulvej , Hansen Johnni , Schernhammer Eva , Ritz Beate 
Published: July 2010

AbstractMajor life events such as divorce, death of a spouse or a child, or long‐term unemployment are stressful to most people and animal models have suggested a link between stress and onset of parkinsonian symptoms. In a large case‐control study based on nationwide registries, we aim to address whether major life events are risk factors for Parkinson's disease. Between 1986 and 2006, we identified 13,695 patients with a (PD) primary diagnosis of PD in the Danish National Hospital Register. Each case was frequency matched by age and gender to five population controls. Information on major life events before onset of PD was ascertained from national registries. Among men, number of life events was associated with risk of Parkinson's disease in an inverse dose‐response manner (P < 0.0001). Compared to no events, three or more events were associated with a 42% lower risk of PD (OR = 0.58; 95 % CI: 0.34–0.99). Life events were not associated with PD in women. In contrast, a higher risk of PD was observed among women who had never been married (1.16; 1.04–1.29) and among men (1.47; 1.18–1.82) and women (1.30; 1.05–1.61) who have never been employees. The lower risk of Parkinson's disease among men who had experienced life events was unexpected but might suggest a general “risk avoidance behavior” in Parkinson's patients. © 2010 Movement Disorder Society
Cell plasticity in homeostasis and regeneration
Authors: Galliot Brigitte , Ghila Luiza 
Published: July 2010

AbstractOver the past decades, genetic analyses performed in vertebrate and invertebrate organisms deciphered numerous cellular and molecular mechanisms deployed during sexual development and identified genetic circuitries largely shared among bilaterians. In contrast, the functional analysis of the mechanisms that support regenerative processes in species randomly scattered among the animal kingdom, were limited by the lack of genetic tools. Consequently, unifying principles explaining how stress and injury can lead to the reactivation of a complete developmental program with restoration of original shape and function remained beyond reach of understanding. Recent data on cell plasticity suggest that beside the classical developmental approach, the analysis of homeostasis and asexual reproduction in adult organisms provides novel entry points to dissect the regenerative potential of a given species, a given organ or a given tissue. As a clue, both tissue homeostasis and regeneration dynamics rely on the availability of stem cells and/or on the plasticity of differentiated cells to replenish the missing structure. The freshwater Hydra polyp provides us with a unique model system to study the intricate relationships between the mechanisms that regulate the maintenance of homeostasis, even in extreme conditions (starvation and overfeeding) and the reactivation of developmental programs after bisection or during budding. Interestingly head regeneration in Hydra can follow several routes according to the level of amputation, suggesting that indeed the homeostatic background dramatically influences the route taken to bridge injury and regeneration. Mol. Reprod. Dev. 77:837–855, 2010. © 2010 Wiley‐Liss, Inc.
Superselective pseudocontinuous arterial spin labeling
Authors: Helle Michael , Norris David G. , Rüfer Susanne , Alfke Karsten , Jansen Olav , van Osch Matthias J. P. 
Published: July 2010

AbstractA new technique for the imaging of flow territories of individual extra‐ and intracranial arteries is presented. The method is based on balanced pseudocontinuous arterial spin labeling but employs additional time‐varying gradients in between the radiofrequency pulses of the long labeling train. The direction of the additional gradient vector is perpendicular to the selected artery and its azimuthal angle is switched after every radiofrequency pulse. The phases of the radiofrequency pulses are adopted to cancel out the phase accrual of the spins at the center of the target vessel due to the extra applied gradients. This results in efficient inversion at the targeted position, whereas elsewhere time‐varying phase changes will result in marginal inversion efficiency. By changing the moment of the added gradients, the size of the labeling focus can be adjusted. Influence of the temporal order of the additional gradients on the labeling efficiency and on the selectivity was investigated by simulations and experimental measurements. In a volunteer study, the acquisition of high signal‐to‐noise ratio flow territory images of small branches of the anterior cerebral artery distal to the circle of Willis was demonstrated. This shows the method's flexibility for dealing with complicated arterial geometries and its ability to superselectively label small intracranial arteries. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Chemical shift–based water/fat separation: A comparison of signal models
Authors: Hernando Diego , Liang Zhi‐Pei , Kellman Peter 
Published: July 2010

AbstractQuantitative water/fat separation in MRI requires careful modeling of the acquired signal. Multiple signal models have been proposed in recent years, but their relative performance has not yet been established. This article presents a comparative study of 12 signal models for quantitative water/fat separation. These models were selected according to three main criteria: magnitude or complex fitting, use of single‐peak or multipeak fat spectrum, and modeling of T decay. The models were compared based on an analysis of the bias and standard deviation of their resulting estimates. Results from theoretical analysis, simulation, phantom experiments, and in vivo data were in good agreement. These results show that (a) complex fitting is uniformly superior to magnitude fitting, (b) multipeak fat modeling is able to remove the bias present in single‐peak fat modeling, and (c) a single‐T model performs best over a range of clinically relevant signal‐to‐noise ratios (SNRs) and water/fat ratios. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Longitudinal tracking of human dendritic cells in murine models using magnetic resonance imaging
Authors: Briley‐Saebo Karen C. , Leboeuf Marylene , Dickson Stephen , Mani Venkatesh , Fayad Zahi A. , Karolina Palucka A. , Banchereau Jacques , Merad Miriam 
Published: July 2010

AbstractEx vivo generated dendritic cells are currently used to induce therapeutic immunity in solid tumors. Effective immune response requires dendritic cells to home and remain in lymphoid organs to allow for adequate interaction with T lymphocytes. The aim of the current study was to detect and track Feridex labeled human dendritic cells in murine models using magnetic resonance imaging. Human dendritic cells were incubated with Feridex and the effect of labeling on dendritic cells immune function was evaluated. Ex vivo dendritic cell phantoms were used to estimate sensitivity of the magnetic resonance methods and in vivo homing was evaluated after intravenous or subcutaneous injection. R2*‐maps of liver, spleen, and draining lymph nodes were obtained and inductively coupled plasma mass spectrometry or relaxometry methods were used to quantify the Feridex tissue concentrations. Correlations between in vivo R2* values and iron content were then determined. Feridex labeling did not affect dendritic cell maturation or function. Phantom results indicated that it was possible to detect 125 dendritic cells within a given slice. Strong correlation between in vivo R2* values and iron deposition was observed. Importantly, Feridex‐labeled dendritic cells were detected in the spleen for up to 2 weeks postintravenous injection. This study suggests that magnetic resonance imaging may be used to longitudinally track Feridex‐labeled human dendritic cells for up to 2 weeks after injection. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Visualization of inert gas wash‐out during high‐frequency oscillatory ventilation using fluorine‐19 MRI
Authors: Wolf Ursula , Scholz Alexander , Terekhov Maxim , Koebrich Rainer , David Matthias , Schreiber Laura Maria 
Published: July 2010

AbstractHigh‐frequency oscillatory ventilation is looked upon as a lung‐protective ventilation strategy. For a further clarification of the physical processes promoting gas transport, a visualization of gas flow and the distribution of ventilation are of considerable interest. Therefore, fluorine‐19 magnetic resonance imaging of the imaging gas octafluorocyclobutane (C4F8) during high‐frequency oscillatory ventilation was performed in five healthy pigs. For that, a mutually compatible ventilation‐imaging system was set up and transverse images were acquired every 5 sec using FLASH sequences on a 1.5 T scanner. Despite a drop in signal‐to‐noise ratio after the onset of high‐frequency oscillatory ventilation, for each pig, the four experiments could be analyzed. A mean wash‐out time (τ) at 5 Hz of 52.7 ± 18 sec and 125.9 ± 39 sec at 10 Hz, respectively, were found for regions of interest including the whole lung. This is in agreement with the clinical findings, in that wash‐out of respiratory gases is significantly prolonged for increased high‐frequency oscillatory ventilation frequencies. Our study could be a good starting‐point for a further optimization of high‐frequency oscillatory ventilation. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Measurement of N‐acetylaspartylglutamate in the human frontal brain by 1H‐MRS at 7 T
Authors: Choi Changho , Ghose Subroto , Uh Jinsoo , Patel Aditya , Dimitrov Ivan E. , Lu Hanzhang , Douglas Deborah , Ganji Sandeep 
Published: July 2010

AbstractN‐Acetylaspartylglutamate in human brain has been measured with difference editing at 7 T. The CH2 proton resonances (∼2.5 ppm) of the aspartyl groups of N‐acetylaspartylglutamate and N‐acetylaspartate were difference edited (MEGA) using 20‐msec gaussian radiofrequency pulses for selective 180° rotations of the coupling partners at 4.61 and 4.38 ppm, respectively. The echo time of the editing sequence, 108 msec, was obtained in phantom tests. Single‐voxel localized in vivo measurements were conducted in the medial prefrontal and right frontal cortices of five healthy volunteers. The gray and white matter fractions within the voxels were obtained from T1‐weighted image segmentation. Using linear regression of the metabolite concentration vs. fractional white matter contents within the voxels, the N‐acetylaspartylglutamate‐to‐N‐acetylaspartate concentration ratios in gray and white matter were estimated to be 0.13 and 0.28 by difference editing (95% confidence intervals 0.07–0.19 and 0.22–0.34), respectively, assuming identical relaxation effects between the metabolites. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Comparison of spectral fitting methods for overlapping J‐coupled metabolite resonances
Authors: Gonenc A. , Govind V. , Sheriff S. , Maudsley A. A. 
Published: July 2010

AbstractThere is increasing interest in the use of two‐dimensional J‐resolved spectroscopic acquisition (multiecho) methods for in vivo proton magnetic resonance spectroscopy due to the improved discrimination of overlapping J‐coupled multiplet resonances that is provided. Of particular interest is the potential for discrimination of the overlapping resonances of glutamate and glutamine. In this study, a new time‐domain parametric spectral model that makes use of all available data is described for fitting the complete two‐dimensional multiecho data, and the performance of this method was compared with fitting of one‐dimensional spectra obtained following averaging multiecho data (echo time‐averaged) and single‐echo time PRESS (Point Resolved Spectroscopy) acquired spectra. These methods were compared using data obtained from a phantom containing typical brain metabolites and a human brain. Results indicate that improved performance and accuracy is obtained for the two‐dimensional acquisition and spectral fitting model. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Adaptive finite element approximation of multiphysics problems: A fluid–structure interaction model problem
Authors: Bengzon Fredrik , Larson Mats G. 
Published: July 2010

AbstractIn this paper we consider finite element simulation of the mechanical response of an elastic solid immersed into a viscous incompressible fluid flow. For simplicity, we assume that the mechanics of the solid is governed by linear elasticity and the motion of the fluid by the Stokes equation. For this one‐way coupled multiphysics problem we derive ana posteriorierror estimate using duality techniques. Based on the estimate we propose an adaptive algorithm that automatically constructs a suitable mesh for the fluid and solid computational domains given a specific goal quantity for the elastic problem. Copyright © 2010 John Wiley & Sons, Ltd.
Variational surface reconstruction based on Delaunay triangulation and graph cut
Authors: Wan Min , Wang Yu , Wang Desheng 
Published: July 2010

AbstractA novel method for surface reconstruction from an unorganized point set is presented. An energy functional based on a weighted minimal surface model is proposed for surface reconstruction, which is efficiently minimized by graph cut methods. By solving the minimization problem on the graph dual to a Delaunay‐based tetrahedral mesh, the advantages of explicit and implicit methods for surface reconstruction are well integrated. A triangular surface mesh homeomorphic to the original surface can be extracted directly from the tetrahedral mesh provided a sufficient sampling density exists. Difficult cases involving undersampling, non‐uniformity, noises and topological complexities can be handled effectively as well. Furthermore, for the first time, multi‐phase surface reconstruction is realized based on the graph cut methods. Various examples are included for demonstrating the efficiency and effectiveness of the proposed method. Copyright © 2010 John Wiley & Sons, Ltd.
Tailoring unstructured meshes for use with a 3D time domain co‐volume algorithm for computational electromagnetics
Authors: Xie Z. Q. , Hassan O. , Morgan K. 
Published: July 2010

AbstractThe Yee algorithm is a highly efficient time domain co‐volume method for computational electromagnetics using a pair of staggered orthogonal cartesian meshes. An equivalent unstructured mesh process is readily implemented on a primal Delaunay tetrahedral mesh and its orthogonal Voronoï dual. The difficulty, for practical applications, is ensuring that both the Delaunay and the Voronoï meshes possess the necessary properties to enable an accurate and efficient solution to be obtained by this approach. This is a mesh generation problem and it is addressed here by using a combination of a point distribution provided by an ideal tetrahedral mesh, a constrained centroidal Voronoï tessellation method and a mesh quality optimization procedure. For the selected application area of electromagnetic wave scattering problems, the computational efficiency is enhanced by using a hybrid primal mesh, consisting of tetrahedral elements in the vicinity of the scatterer and hexahedral elements elsewhere. Three examples are included to demonstrate the viability of the proposed approach and to indicate the numerical performance that can be achieved. Copyright © 2010 John Wiley & Sons, Ltd.
Study on elastic modulus of crosslinked polyurethane/organoclay nanocomposites
Authors: Joulazadeh Mehrnaz , Navarchian Amir. H. 
Published: July 2010

AbstractIn this paper, two polyurethane/clay nanocomposite systems with crosslinked structure were synthesized via in situ polymerization of a polyether‐ as well as a polyester‐based prepolymer with methylene‐bis‐ortho‐chloroanilline (MOCA). Two types of modified clays with different organic modifiers were used in order to see the effect of compatibility between polymer matrix and clays on elastic modulus of nanocomposites. The morphology and the dispersion of clay layers in polyurethanes have been characterized by X‐ray diffraction (XRD) and microscopic techniques. The changes of elastic modulus of nanocomposites with clay content were examined and compared with those predicted by some conventional composite models. The results showed a reasonable fitting of experimental and theoretical values only at very low clay contents. As the clay content exceeds 1.5 wt% in this system, a reduction in elastic modulus was experimentally observed due to insufficient dispersion degree of silicate layers throughout the crosslinked matrix. This behavior was not predicted with the conventional composite theories. A new model on the basis of Wu model was then developed in order to predict the reduction of elastic modulus at various clay contents in crosslinked PU matrix. This model fitted reasonably the experimental results. Copyright © 2010 John Wiley & Sons, Ltd.
Sam68 up‐regulation correlates with, and its down‐regulation inhibits, proliferation and tumourigenicity of breast cancer cells
Authors: Song Libing , Wang Lan , Li Yun , Xiong Huaping , Wu Jueheng , Li Jun , Li Mengfeng 
Published: July 2010

AbstractThe biosynthesis and metabolism of RNA play important roles in regulating gene expression. On the other hand, it has been shown that RNA expression profiling is differentially distinct between cancer and normal cells, suggesting the possibility that aberrant regulation of RNA metabolism might be associated with the development and progression of cancer. In the current study, we found that Sam68, an RNA‐binding protein that links cellular signalling to RNA processing, was markedly overexpressed in breast cancer cells and tissues. Immunohistochemical analysis showed that the expression and cytoplasmic localization of Sam68 significantly correlated with clinical characteristics of patients, including clinical stage, tumour‐nodule‐metastasis (TNM) classification, histological grade, and ER expression. Univariate and multivariate analyses showed that the expression level and cytoplasmic localization of Sam68 were identified as independent prognostic factors. Furthermore, we found that siRNA knockdown of endogenous Sam68 inhibited cell proliferation and tumourigenicity of breast cancer cells in vitro, through blocking the G1 to S phase transition. Moreover, we demonstrated that the anti‐proliferative effect of silencing Sam68 on breast cancer cells was associated with up‐regulation of cyclin‐dependent kinase inhibitor p21Cip1 and p27Kip1, enhanced transactivation of FOXO factors, and attenuation of Akt/GSK‐3β signalling. Taken together, our results suggest that Sam68 might play an important role in promoting the proliferation and carcinogenesis of human breast cancer, and thereby might be a novel and useful prognostic marker and a potential target for human breast cancer treatment. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Assessment of the influence of different sample processing and cold storage duration on plant free proline content analyses
Authors: Teklić Tihana , Špoljarević Marija , Stanisavljević Aleksandar , Lisjak Miroslav , Vinković Tomislav , Parađiković Nada , Andrić Luka , Hancock John T. 
Published: July 2010

AbstractIntroduction – A method which is widely accepted for the analysis of free proline content in plant tissues is based on the use of 3% sulfosalicylic acid as an extractant, followed by spectrophotometric quantification of a proline–ninhydrin complex in toluene. However, sample preparation and storage may influence the proline actually measured. This may give misleading or difficult to compare data.Objective and Methodology – To evaluate free proline levels fresh and frozen strawberry (Fragaria × ananassa Duch.) leaves and soybean [Glycine max (L.) Merr.] hypocotyl tissues were used. These were ground with or without liquid nitrogen and proline extracted with sulfosalicylic acid. A particular focus was the influence of plant sample cold storage duration (1, 4 and 12 weeks at −20°C) on tissue proline levels measured.Results – The free proline content analyses, carried out in leaves of Fragaria × ananassa Duch. as well as in hypocotyls of Glycine max (L.) Merr., showed a significant influence of the sample preparation method and cold storage period. Long‐term storage of up to 12 weeks at −20°C led to a significant increase in the measured proline in all samples analysed.Conclusion – The observed changes in proline content in plant tissue samples stored at −20°C indicate the likelihood of the over‐estimation of the proline content if the proline analyses are delayed. Plant sample processing and cold storage duration seem to have an important influence on results of proline analyses. Therefore it is recommended that samples should be ground fresh and analysed immediately. Copyright © 2010 John Wiley & Sons, Ltd.
Preimplantation genetic diagnosis in Saudi Arabia: parents' experience and attitudes
Authors: Alsulaiman Ayman , Al‐Odaib Ali , Rijjal Al , Hewison Jenny 
Published: July 2010

AbstractBackgroundPreimplantation genetic diagnosis (PGD) has been proposed as an alternative to prenatal diagnosis (PND). This study compares the attitudes towards PGD of four groups of parents in Saudi Arabia: two groups at genetic risk for different conditions but with no experience of PGD procedures and two groups who had experience, either of PGD or of in vitro fertilisation (IVF) for infertility.MethodsOne hundred and eighty four participants attending the King Faisal Specialist Hospital and Research Centre (KFSH&RC) in Riyadh were interviewed using a semi‐structured questionnaire: 49 had children affected by a haemoglobin disorder, 48 had children with non‐syndromic deafness, 37 were attending the PGD service and 50 were attending IVF services for infertility.ResultsOpinions in the two genetic groups were very similar: families were enthusiastic about PGD and relatively unconcerned about its technical limitations or the desirability of a confirmatory PND. The technical limitations of PGD and the moral status of embryos were of greatest concern to the PGD group. Waiting for the pregnancy result was the most commonly mentioned concern in the PGD and IVF groups.ConclusionPGD might be considered for a range of conditions in Saudi Arabia. However, it is not an easy option, and couples must be selected and counselled appropriately. Copyright © 2010 John Wiley & Sons, Ltd.
A quantitative evaluation of the regulatory assessment of the benefits and risks of rofecoxib relative to naproxen: an application of the incremental net‐benefit framework
Authors: Lynd Larry D. , Marra Carlo A. , Najafzadeh Mehdi , Sadatsafavi Mohsen 
Published: July 2010

AbstractPurposeTo undertake a quantitative benefit–risk analysis of rofecoxib relative to naproxen using an incremental net‐benefit (INB) analysis from the societal perspective, using the same data evaluated by the Health Canada and US FDA expert advisory panels.MethodsWe developed a discrete event simulation model to calculate the INB of rofecoxib relative to naproxen in arthritis patients over a 1‐year time horizon. All outcomes were weighted using societal utilities for each health state which facilitated the use of quality‐adjusted life years (QALYs) as the outcome. Probability distributions were incorporated for each model parameter to facilitate a probabilistic analysis using second‐order Monte Carlo simulation.ResultsIn the base case analysis, the mean INB (SD) of rofecoxib relative to naproxen was 0.0002 (0.415) QALYs per patient over 12 months of treatment, or 0.2 QALYs per 1000 patients treated. The probabilistic sensitivity analysis resulted in a mean INB of 0.0022 QALYs (95%CI −0.0005, 0.0051). Overall, the INB associated with rofecoxib relative to naproxen was ≥0 in 94% of the iterations of the model.ConclusionsThis analysis illustrates the application of the incremental net‐benefit framework to quantitative benefit–risk evaluation, and suggests that the potential benefits of rofecoxib outweigh the potential harms relative to naproxen over 1 year from the societal perspective under the assumptions of this model. Copyright © 2010 John Wiley & Sons, Ltd.