bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential effects of Epigallocatechin‐3‐gallate containing supplements on correcting skeletal defects in a Down syndrome mouse model
Authors: Abeysekera Irushi , Thomas Jared , Georgiadis Taxiarchis M. , Berman Alycia G. , Hammond Max A. , Dria Karl J. , Wallace Joseph M. , Roper Randall J. 
Published: January 2016

ScopeDown syndrome (DS), caused by trisomy of human chromosome 21 (Hsa21), is characterized by a spectrum of phenotypes including skeletal abnormalities. The Ts65Dn DS mouse model exhibits similar skeletal phenotypes as humans with DS. DYRK1A, a kinase encoded on Hsa21, has been linked to deficiencies in bone homeostasis in DS mice and individuals with DS. Treatment with Epigallocatechin‐3‐gallate (EGCG), a known inhibitor of Dyrk1a, improves some skeletal abnormalities associated with DS in mice. EGCG supplements are widely available but the effectiveness of different EGCG‐containing supplements has not been well studied.Methods and resultsSix commercially available supplements containing EGCG were analyzed, and two of these supplements were compared with pure EGCG for their impact on skeletal deficits in a DS mouse model. The results demonstrate differential effects of commercial supplements on correcting skeletal abnormalities in Ts65Dn mice. Different EGCG‐containing supplements display differences in degradation, polyphenol content, and effects on trisomic bone.ConclusionThis work suggests that the dose of EGCG and composition of EGCG‐containing supplements may be important in correcting skeletal deficits associated with DS. Careful analyses of these parameters may lead to a better understanding of how to improve skeletal and other deficits that impair individuals with DS.
Conformation analysis of d‐glucaric acid in deuterium oxide by NMR based on its JHH and JCH coupling constants
Authors: Enomoto‐Rogers Yukiko , Masaki Hisaharu , Ito Tetsuya , Furihata Kazuo , Iwata Tadahisa 
Published: January 2016

Abstractd‐Glucaric acid (GA) is an aldaric acid and consists of an asymmetric acyclic sugar backbone with a carboxyl group positioned at either end of its structure (i.e., the C1 and C6 positions). The purpose of this study was to conduct a conformation analysis of flexible GA as a solution in deuterium oxide by NMR spectroscopy, based on J‐resolved conformation analysis using proton–proton (3JHH) and proton–carbon (2JCH and 3JCH) coupling constants, as well as nuclear overhauser effect spectroscopy (NOESY). The 2JCH and 3JCH coupling constants were measured using the J‐resolved heteronuclear multiple bond correlation (HMBC) NMR technique. NOESY correlation experiments indicated that H2 and H5 were in close proximity, despite the fact that these protons were separated by too large distance in the fully extended form of the chain structure to provide a NOESY correlation. The validities of the three possible conformers along the three different bonds (i.e., C2C3, C3C4, and C4C5) were evaluated sequentially based on the J‐coupling values and the NOESY correlations. The results of these analyses suggested that there were three dominant conformers of GA, including conformer 1, which was H2H3:gauche, H3H4:anti, and H4H5:gauche; conformer 2, which was H2H3:gauche, H3H4:anti, and H4H5:anti; and conformer 3, which was H2H3:gauche, H3H4: gauche, and H4H5:anti. These results also suggested that all three of these conformers exist in equilibrium with each other. Lastly, the results of the current study suggested that the conformational structures of GA in solution were ‘bent’ rather than being fully extended. Copyright © 2016 John Wiley & Sons, Ltd.
Cardiac MR elastography of the mouse: Initial results
Authors: Liu Yifei , Royston Thomas J. , Klatt Dieter , Lewandowski E. Douglas 
Published: January 2016

PurposeMany cardiovascular diseases are associated with abnormal function of myocardial contractility or dilatability, which is related to elasticity changes of the myocardium over the cardiac cycle. The mouse is a common animal model in studies of the progression of various cardiomyopathies. We introduce a novel noninvasive approach using microscopic scale MR elastography (MRE) to measure the myocardium stiffness change during the cardiac cycle on a mouse model.MethodsA harmonic mechanical wave of 400 Hz was introduced into the mouse body. An electrocardiograph‐gated and respiratory‐gated fractional encoding cine‐MRE pulse sequence was applied to encode the resulting oscillatory motion on a short‐axis slice of the heart. Five healthy mice (age range, 3–13.5 mo) were examined. The weighted summation effective stiffness of the left ventricle wall during the cardiac cycle was estimated.ResultsThe ratio of stiffness at end diastole and end systole was 0.5–0.67. Additionally, variation in shear wave amplitude in the left ventricle wall throughout the cardiac cycle was measured and found to correlate with estimates of stiffness variation.ConclusionThis study demonstrates the feasibility of implementing cardiac MRE on a mouse model. Magn Reson Med 76:1879–1886, 2016. © 2016 International Society for Magnetic Resonance in Medicine
Effect of temporal resolution and serial autocorrelations in event‐related functional MRI
Authors: Sahib Ashish Kaul , Mathiak Klaus , Erb Michael , Elshahabi Adham , Klamer Silke , Scheffler Klaus , Focke Niels K , Ethofer Thomas 
Published: January 2016

PurposeTo assess the impact of colored noise on statistics in event‐related functional MRI (fMRI) (visual stimulation using checkerboards) acquired by simultaneous multislice imaging enabling repetition times (TRs) between 2.64 to 0.26 s.MethodsT‐values within the visual cortex obtained with analysis tools that assume a first‐order autoregressive plus white noise process (AR(1)+w) with a fixed AR coefficient versus higher‐order AR models with spatially varying AR coefficients were compared. In addition, dependency of T‐values on correction of physiological noise (respiration, heart rate) was evaluated.ResultsOptimal statistical power was obtained for a TR of 0.33 s, but T‐values as obtained by AR(1)+w models were strongly dependent on the predefined AR coefficients in fMRI with short TRs which required higher‐order AR models to achieve stable statistics. Direct estimation of AR coefficients revealed the highest values within the default mode network while physiological noise had little influence on statistics in cortical structures.ConclusionColored noise in event‐related fMRI obtained at short TRs originates mainly from neural sources and calls for more sophisticated correction of serial autocorrelations which cannot be achieved with standard methods relying on AR(1)+w models with globally fixed AR coefficients. Magn Reson Med 76:1805–1813, 2016. © 2016 International Society for Magnetic Resonance in Medicine
Matrix pencil decomposition of time‐resolved proton MRI for robust and improved assessment of pulmonary ventilation and perfusion
Authors: Bauman Grzegorz , Bieri Oliver 
Published: January 2016

PurposeTo present an improved and robust method of pulmonary function assessment from time‐resolved proton MRI using a matrix pencil (MP) method in combination with a linear least squares analysis.MethodsSimulations of the signal time course in lung parenchyma were performed to compare the accuracy of Fourier decomposition (FD) and MP methods for the estimation of respiratory and cardiac amplitudes. Series of two‐dimensional time‐resolved lung images were acquired in healthy volunteers at 1.5 T using ultra‐fast steady‐state free precession. Qualitative lung ventilation‐ and perfusion‐weighted images as well as a quantitative map of fractional ventilation, perfusion, and blood arrival time were calculated using the proposed MP method and compared with the contemporary FD technique. A region‐of‐interest analysis was performed on the quantitative data.ResultsThe signal analysis performed using MP decomposition resulted in reduced variability of the estimated respiratory and cardiac amplitudes in comparison with FD for both simulated and in vivo data.ConclusionMP decomposition provides an automatic, robust, and more accurate estimation of amplitudes of respiratory and cardiac signal modulations in the lung parenchyma than the contemporary FD technique. Magn Reson Med 77:336–342, 2017. © 2016 Wiley Periodicals, Inc.
Efficient gradient calibration based on diffusion MRI
Authors: Teh Irvin , Maguire Mahon L. , Schneider Jürgen E. 
Published: January 2016

PurposeTo propose a method for calibrating gradient systems and correcting gradient nonlinearities based on diffusion MRI measurements.MethodsThe gradient scaling in x, y, and z were first offset by up to 5% from precalibrated values to simulate a poorly calibrated system. Diffusion MRI data were acquired in a phantom filled with cyclooctane, and corrections for gradient scaling errors and nonlinearity were determined. The calibration was assessed with diffusion tensor imaging and independently validated with high resolution anatomical MRI of a second structured phantom.ResultsThe errors in apparent diffusion coefficients along orthogonal axes ranged from −9.2% ± 0.4% to + 8.8% ± 0.7% before calibration and −0.5% ± 0.4% to + 0.8% ± 0.3% after calibration. Concurrently, fractional anisotropy decreased from 0.14 ± 0.03 to 0.03 ± 0.01. Errors in geometric measurements in x, y and z ranged from −5.5% to + 4.5% precalibration and were likewise reduced to −0.97% to + 0.23% postcalibration. Image distortions from gradient nonlinearity were markedly reduced.ConclusionPeriodic gradient calibration is an integral part of quality assurance in MRI. The proposed approach is both accurate and efficient, can be setup with readily available materials, and improves accuracy in both anatomical and diffusion MRI to within ±1%. Magn Reson Med 77:170–179, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.
F2 in Kunststoffen und Lasern
Authors: van Bonn Rolf , Feinäugle Mathias 
Published: January 2016

AbstractVom kleinen Lackierbetrieb bis zum Weltkonzern: Die Industrie setzt täglich große Mengen elementares Fluorgas ein – für Laser, Oberflächenbehandlung von Kunststoffen und Ausgangsstoffe der Atomenergie.
Efficacy and safety of two administration modes of an intra‐detrusor injection of 750 units dysport® (abobotulinumtoxinA) in patients suffering from refractory neurogenic detrusor overactivity (NDO): A randomised placebo‐controlled phase IIa study
Authors: Denys Pierre , Del Popolo Giulio , Amarenco Gerard , Karsenty Gilles , Le Berre Philippe , Padrazzi Bruno , Picaut Philippe ,   On Behalf of the Dysport Study Group
Published: January 2016

AimsAssess the efficacy and safety of abobotulinumtoxinA (Dysport®) in adult patients with neurogenic detrusor overactivity (NDO).MethodsThis Phase IIa, international, multicentre, double‐blind, randomised, placebo controlled, pilot study enrolled 47 patients with NDO and urinary incontinence resulting from spinal cord injury (SCI) or multiple sclerosis (MS). Patients were treated with 15 intra‐detrusor injections of Dysport 750 U or the equivalent placebo (n = 16 and 7) or 30 injections of Dysport 750 U or the equivalent placebo (n = 17 and 7). Primary endpoint was change from baseline in mean number of daily incontinence episode frequency (IEF) at day 84. Secondary endpoints included change from baseline in urodynamic parameters and quality of life (QOL). A safety assessment was also conducted.ResultsAdjusted mean changes from baseline in IEF were −3.2 (−76%) and −1.7 (−15%) for 15 injections Dysport and placebo groups, respectively, (P = 0.1103) and −3.2 (−88%) and −2.6 (−73%) for 30 injections Dysport and placebo groups, respectively, (P = 0.0686). Statistically significant improvements in maximum cystometric capacity, maximum detrusor pressure and volume at first contraction were reported in the Dysport groups compared with placebo (P < 0.05). Improvements in QOL were reported. Three muscle weakness episodes were reported as serious adverse events in two tetraplegic and one paraplegic patient, all in the 15 injections Dysport group.ConclusionsBoth 15 and 30 injections administration modes of Dysport decreased daily IEF and resulted in significant improvements in urodynamic parameters in NDO patients with MS or SCI. Reduction to 15 injection sites did not appear to be associated with any impact on efficacy. Neurourol. Urodynam. 36:457–462, 2017. © 2016 Wiley Periodicals, Inc.
Stroke assessment with intravoxel incoherent motion diffusion‐weighted MRI
Authors: Suo Shiteng , Cao Mengqiu , Zhu Wanqiu , Li Lei , Li Jun , Shen Fei , Zu Jinyan , Zhou Zien , Zhuang Zhiguo , Qu Jianxun , Chen Zengai , Xu Jianrong 
Published: January 2016

Intravoxel incoherent motion (IVIM) diffusion‐weighted MRI can simultaneously measure diffusion and perfusion characteristics in a non‐invasive way. This study aimed to determine the potential utility of IVIM in characterizing brain diffusion and perfusion properties for clinical stroke. The multi‐b‐value diffusion‐weighted images of 101 patients diagnosed with acute/subacute ischemic stroke were retrospectively evaluated. The diffusion coefficient D, representing the water apparent diffusivity, was obtained by fitting the diffusion data with increasing high b‐values to a simple mono‐exponential model. The IVIM‐derived perfusion parameters, pseudodiffusion coefficient D*, vascular volume fraction f and blood flow‐related parameter fD*, were calculated with the bi‐exponential model. Additionally, the apparent diffusion coefficient (ADC) was fitted according to the mono‐exponential model using all b‐values. The diffusion parameters for the ischemic lesion and normal contralateral region were measured in each patient. Statistical analysis was performed using the paired Student t‐test and Pearson correlation test. Diffusion data in both the ischemic lesion and normal contralateral region followed the IVIM bi‐exponential behavior, and the IVIM model showed better goodness of fit than the mono‐exponential model with lower Akaike information criterion values. The paired Student t‐test revealed significant differences for all diffusion parameters (all P < 0.001) except D* (P = 0.218) between ischemic and normal areas. For all patients in both ischemic and normal regions, ADC was significantly positively correlated with D (both r = 1, both P < 0.001) and f (r = 0.541, P < 0.001; r = 0.262, P = 0.008); significant correlation was also found between ADC and fD* in the ischemic region (r = 0.254, P = 0.010). For all pixels within the region of interest from a representative subject in both ischemic and normal regions, ADC was significantly positively correlated with D (both r = 1, both P < 0.001), f (r = 0.823, P < 0.001; r = 0.652, P < 0.001) and fD* (r = 0.294, P < 0.001; r = 0.340, P < 0.001). These findings may have clinical implications for the use of IVIM imaging in the assessment and management of acute/subacute stroke patients. Copyright © 2016 John Wiley & Sons, Ltd.
Level‐set topology optimization with many linear buckling constraints using an efficient and robust eigensolver
Authors: Dunning Peter D. , Ovtchinnikov Evgueni , Scott Jennifer , Kim H. Alicia 
Published: January 2016

SummaryLinear buckling constraints are important in structural topology optimization for obtaining designs that can support the required loads without failure. During the optimization process, the critical buckling eigenmode can change; this poses a challenge to gradient‐based optimization and can require the computation of a large number of linear buckling eigenmodes. This is potentially both computationally difficult to achieve and prohibitively expensive. In this paper, we motivate the need for a large number of linear buckling modes and show how several features of the block Jacobi conjugate gradient (BJCG) eigenvalue method, including optimal shift estimates, the reuse of eigenvectors, adaptive eigenvector tolerances and multiple shifts, can be used to efficiently and robustly compute a large number of buckling eigenmodes. This paper also introduces linear buckling constraints for level‐set topology optimization. In our approach, the velocity function is defined as a weighted sum of the shape sensitivities for the objective and constraint functions. The weights are found by solving an optimization sub‐problem to reduce the mass while maintaining feasibility of the buckling constraints. The effectiveness of this approach in combination with the BJCG method is demonstrated using a 3D optimization problem. Copyright © 2016 John Wiley & Sons, Ltd.
A transformation approach for efficient evaluation of oscillatory surface integrals arising in three‐dimensional boundary element methods
Authors: Hargreaves Jonathan A. , Lam Yiu W. , Langdon Stephen 
Published: January 2016

SummaryWe propose a method for efficient evaluation of surface integrals arising in boundary element methods for three‐dimensional Helmholtz problems (with real positive wavenumber k), modelling wave scattering and/or radiation in homogeneous media. To reduce the number of degrees of freedom required when k is large, a common approach is to include in the approximation space oscillatory basis functions, with support extending across many wavelengths. A difficulty with this approach is that it leads to highly oscillatory surface integrals whose evaluation by standard quadrature would require at least O(k2) quadrature points. Here, we use equivalent contour integrals developed for aperture scattering in optics to reduce this requirement to O(k), and possible extensions to reduce it further to O(1) are identified. The contour integral is derived for arbitrary shaped elements, but its application is limited to planar elements in many cases. In addition, the transform regularises the singularity in the surface integrand caused by the Green's function, including for the hyper‐singular case under appropriate conditions. An open‐source Matlab™code library is available to demonstrate our routines. © 2016 The Authors International Journal for Numerical Methods in Engineering Published by John Wiley & Sons Ltd.
Pore‐scale modeling of deformation and shear band bifurcation in porous crystalline rocks
Authors: Tjioe Martin , Borja Ronaldo I. 
Published: January 2016

SummaryWe develop a computational framework that captures the microfracture processes leading to shear band bifurcation in porous crystalline rocks. The framework consists of computational homogenization on a representative elementary volume that upscales the pore‐scale microfracture processes to the continuum scale. The assumed enhanced strain finite element approach is used to capture the discontinuous displacement field generated by the microfractures. Homogenization at the continuum scale results in incrementally nonlinear material response, in which the overall constitutive tangent tensor varies with the stress state and with the loading direction. Continuum bifurcation detects the formation of a shear band on the representative elementary volume level; multi‐dimensional strain probes, necessitated by the incremental nonlinearity of the overall constitutive response, determine the most critical orientation of shear band bifurcation. Numerical simulations focus on microfracturing at the pore scale with either predominant interface separation or predominant interface contact modes. Results suggest a non‐associative overall plastic flow and shear band bifurcation that depends on the microfracture length and the characteristic sliding distance related to slip weakening. Copyright © 2016 John Wiley & Sons, Ltd.
How well does the standard body mass index or variations with a different exponent predict human lifespan?
Authors: Foster Dean , Karloff Howard , Shirley Kenneth E. 
Published: January 2016

ObjectiveThe objective was twofold: (1) to estimate for each individual the body mass index (BMI) which is associated with the lowest risk of death, and (2) to study variants of the BMI formula to determine which gives the best predictions of death.MethodsTreating BMI = mass/height2 as a continuous variable and estimating its interaction effects with several other variables, this study analyzed the NIH‐AARP study data set of approximately 566,000 individuals and fit Cox proportional hazards models to the survival times.ResultsFor each individual, a “personalized optimal BMI,” the BMI for that individual which, according to the model, is associated with the lowest risk of death, is estimated. The average personalized optimal BMI is approximately 26, which is in the current “overweight” category. In fact, mass/height is a better predictor of death on the data set than BMI itself.ConclusionsThe model suggests that an individual's “optimal” BMI depends on his or her features; “one‐size‐fits‐all” recommendations may be not best.
Development of tools to study personal weight control strategies: OxFAB taxonomy
Authors: Hartmann‐Boyce Jamie , Aveyard Paul , Koshiaris Constantinos , Jebb Susan A. 
Published: January 2016

ObjectiveTo describe the development of the Oxford Food and Activity Behaviors (OxFAB) taxonomy and questionnaire to explore the cognitive and behavioral strategies used by individuals during weight management attempts.MethodsThe taxonomy was constructed through a qualitative analysis of existing resources and a review of existing behavior change taxonomies and theories. The taxonomy was translated into a questionnaire to identify strategies used by individuals. Think‐aloud interviews were conducted to test the face/concept validity of the questionnaire, and test–retest reliability was assessed in a sample of 138 participants.ResultsThe OxFAB taxonomy consists of 117 strategies grouped into 23 domains. Compared to taxonomies used to describe interventions, around half of the domains and strategies identified are unique to the OxFAB taxonomy. The OxFAB questionnaire consists of 117 questions, one for each strategy from the taxonomy. Test–retest resulted in a mean PABAK score of 0.61 (SD 0.15). Questions were revised where appropriate.ConclusionsThe OxFAB taxonomy and questionnaire provide a conceptual framework to identify the cognitive and behavioral strategies used by individuals during attempts at weight control.
Marginal Pricing and Student Investment in Higher Education
Authors: Hemelt Steven W. , Stange Kevin M. 
Published: January 2016

AbstractThis paper examines the effect of marginal price on students’ educational investments using rich administrative data on students at Michigan public universities. Marginal price refers to the amount colleges charge for each additional credit taken in a semester. Institutions differ in how they price credits above the full‐time minimum (of 12 credits), with many institutions reducing the marginal price of such credits to zero. We find that a zero marginal price induces a modest share of students (i.e., 7 percent) to attempt up to one additional class (i.e., three credits) but also increases withdrawals and lowers course performance. The analysis generally suggests minimal impacts on credits earned and the likelihood of meeting “on‐time” benchmarks toward college completion, though estimates for these outcomes are less precise and more variable across specifications. Consistent with theory, the effect on attempted credits is largest among students who would otherwise locate at the full‐time minimum, which includes lower‐achieving and socioeconomically disadvantaged students.