bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dyskinesia Matters
Authors: Cenci M. Angela , Riggare Sara , Pahwa Rajesh , Eidelberg David , Hauser Robert A. 
Published: December 2019

AbstractLevodopa‐induced dyskinesia (LID) represents a significant source of discomfort for people with Parkinson's disease (PD). It negatively affects quality of life, it is associated with both motor and nonmotor fluctuations, and it brings an increased risk of disability, balance problems, and falls. Although the prevalence of severe LID appears to be lower than in previous eras (likely owing to a more conservative use of oral levodopa), we have not yet found a way to prevent the development of this complication. Advanced surgical therapies, such as deep brain stimulation, ameliorate LID, but only a minority of PD patients qualify for these interventions. Although some have argued that PD patients would rather be ON with dyskinesia than OFF, the deeper truth is that patients would very much prefer to be ON without dyskinesia. As researchers and clinicians, we should aspire to make that goal a reality. To this end, translational research on LID is to be encouraged and persistently pursued. © 2019 International Parkinson and Movement Disorder Society
Evidence of positively selected G6PD A‐ allele reduces risk of Plasmodium falciparum infection in African population on Bioko Island
Authors: Liang Xue‐Yan , Chen Jiang‐Tao , Ma Yan‐Bo , Huang Hui‐Ying , Xie Dong‐De , Monte‐Nguba Santiago‐m , Ehapo Carlos Salas , Eyi Urbano Monsuy , Zheng Yu‐Zhong , Liu Xiang‐Zhi , Zha Guang‐Cai , Lin Li‐Yun , Chen Wei‐Zhong , Zhou Xia , Lin Min 
Published: December 2019

AbstractBackgroundGlucose‐6‐phosphate dehydrogenase (G6PD) is an essential enzyme that protects red blood cells from oxidative damage. Although G6PD‐deficient alleles appear to confer a protective effect of malaria, the link with clinical protection against Plasmodium infection is conflicting.MethodsA case–control study was conducted on Bioko Island, Equatorial Guinea and further genotyping analysis used to detect natural selection of the G6PD A‐ allele.ResultsOur results showed G6PD A‐ allele could significantly reduce the risk of Plasmodium falciparum infection in male individuals (adjusted odds ratio [AOR], 0.43; 95% confidence interval [CI], 0.20–0.93; p < .05) and homozygous female individuals (AOR, 0.11; 95% CI, 0.01–0.84; p < .05). Additionally, the parasite densities were significantly different in the individuals with different G6PD A‐ alleles and individual levels of G6PD enzyme activity. The pattern of linkage disequilibrium and results of the long‐range haplotype test revealed a strong selective signature in the region encompassing the G6PD A‐ allele over the past 6,250 years. The network of inferred haplotypes suggested a single origin of the G6PD A‐ allele in Africans.ConclusionOur findings demonstrate that glucose‐6‐phosphate dehydrogenase (G6PD) A‐ allele could reduce the risk of P. falciparum infection in the African population and indicate that malaria has a recent positive selection on G6PD A‐ allele.
Analysis on predistortion algorithm for improving adjacent channel leakage ratio of radio over fiber systems
Authors: Yang Bo , He Hongxia , Yang Shuna , Ou Jun , Zhai Yanrong , Chi Hao 
Published: December 2019

AbstractNonlinear distortion introduced by optoelectronic components imposes serious limitations on the performance of radio over fiber (RoF) systems, such as dynamic range and adjacent channel leakage ratio (ACLR). In this article, we focus on the impact of digital predistortion (DPD) on the ACLR improvement in a wideband RoF system with multiple carriers. Three key factors, that is, the order of DPD algorithm, the initial phases of carriers, and the processing bandwidth of the predistortion module, are all taken into account in investigating the influence of predistortion on the ACLR performance of RoF systems. A preliminary experiment verifies the effectiveness of predistortion technique for improving the ACLR performance. Quantitative simulation results demonstrate that with the increase in the order of DPD algorithm, the ACLR performance can be significantly improved while the phase randomness within 10 carriers leads to an ACLR fluctuation up to 5 dB. The dependence of the ACLR improvement on the processing bandwidth of the predistortion module, which is very important in practical application, has also been quantitatively studied.
Circularly polarized hexagonal ring microstrip patch antenna with asymmetrical feed and DGS
Authors: Maurya Rakesh Kumar , Kanaujia Binod K. , Gautam A. K. , Chatterji S. , Singh Anil Kumar 
Published: December 2019

AbstractA novel circularly polarized hexagonal ring microstrip patch antenna with asymmetrical feed is proposed for S, C, and X‐band applications. A semi‐arc‐shaped slot is integrated into the ground plane, and the hexagonal ring is tilted by an angle of 25° with respect to the microstrip‐line feed (asymmetric), which creates a circularly polarized UWB. The simulation of the proposed antenna is carried out using Ansoft HFSS v.13 and the measurement is done with an N5230A vector network analyzer. The simulated and the measured results of our proposed antenna are in good agreement. The successful implementation of the asymmetrical feed shows a broader impedance bandwidth of 134% (B.W = 9.55 GHz) from 2.34 to 11.89 GHz at 7.12 GHz of the center frequency. The 3‐dB axial ratio B.W is 2.8% (7.1‐7.3 GHz) and 21.8% (9.8‐12.2 GHz) in the UWB range. The average gain of the proposed antenna is 4.15 dBi. Good RHCP waves are also found in the x‐z and y‐z planes. The proposed antenna can be effectively used in S, C, and X‐band applications.
Improved gradient‐echo 3D magnetic resonance imaging using compressed sensing and Toeplitz encoding with phase‐scrambled RF excitation
Authors: Wang Haifeng , Liang Dong , Su Shi , King Kevin F. , Chang Yuchou , Liu Xin , Zheng Hairong , Ying Leslie 
Published: December 2019

PurposeTo develop a novel three‐dimensional (3D) hybrid‐encoding framework using compressed sensing (CS) and Toeplitz encoding with variable phase‐scrambled radio‐frequency (RF) excitation, which has the following advantages: low power deposition of RF pulses, reduction of the signal dynamic range, no additional hardware requirement, and signal‐to‐noise ratio (SNR) improvement.MethodsIn light of the actual imaging framework of magnetic resonance imaging (MRI) scanners, we applied specially tailored RF pulses with phase‐scrambled RF excitation to implement a 3D hybrid Fourier‐Toeplitz encoding method based on 3D gradient‐recalled echo pulse (GRASS) sequence. This method exploits Toeplitz encoding along the phase encoding direction, while keeping Fourier encoding along the readout and slice encoding directions. Phantom experiments were conducted to optimize the amplitude of specially tailored RF pulses in the 3D GRASS sequence. In vivo experiments were conducted to validate the feasibility of the proposed method, and simulations were conducted to compare the 3D hybrid‐encoding method with Fourier encoding and other non‐Fourier encoding methods.ResultsAn optimized low RF amplitude was obtained in the phantom experiments. Using the optimized specially tailored RF pulses, both the watermelon and knee experiments demonstrated that the proposed method was able to preserve more image details than the conventional 3D Fourier‐encoded methods at acceleration factors of 3.1 and 2.0. Additionally, SNR was improved because of no additional gradients and 3D volume encoding, when compared with single‐slice scanning without 3D encoding. Simulation results demonstrated that the proposed scheme was superior to the conventional Fourier encoding method, and obtained comparative performance with other non‐Fourier encoding methods in preserving details.ConclusionsWe developed a practical hybrid‐encoding method for 3D MRI with specially tailored RF pulses of phase‐scrambled RF excitation. The proposed method improves image SNR and detail preservation compared with the conventional Fourier encoding methods. Furthermore, our proposed method exhibits superior performance in terms of detail preservation, compared with the conventional Fourier encoding method.
4D flow imaging with UNFOLD in a reduced FOV
Authors: Wink Clarissa , Bassenge Jean Pierre , Ferrazzi Giulio , Schaeffter Tobias , Schmitter Sebastian 
Published: December 2019

PurposeTwo‐dimensional selective excitation (2DRF) allows shortening 4D flow scan times by reducing the FOV, but the longer 2DRF pulse duration decreases the temporal resolution, yielding underestimated peak flow values. Multiple k‐space lines per cardiac phase, nl ≥ 2, are commonly applied in 4D flow MRI to shorten the inherent long scan times. We demonstrate that 2DRF 4D flow with nl ≥ 2 can be easily combined with UNFOLD (UNaliasing by Fourier‐encoding the Overlaps using the temporaL Dimension), a technique that allows regaining nominally the temporal resolution of the respective acquisition with nl = 1, to assure peak flow quantification.MethodsTwo different 2DRF pulses with spiral k‐space trajectories were designed and integrated into a 4D flow sequence. Flow phantom experiments and 7 healthy control 4D flow in vivo measurements, with and without UNFOLD reconstructions, were compared with conventional reconstruction and 1D slab‐selective excitation (1DRF) by evaluating time‐resolved flow curves, peak flow, peak velocity, blood flow volume per cardiac cycle, and spatial aliasing.ResultsApplying UNFOLD to 4D flow imaging with 2DRF and reduced FOV increased the quantified in vivo peak flow values significantly by 3.7% ± 2.3% to 5.2% ± 2.4% (P < .05). Accordingly, the peak flow underestimation of 2DRF scans compared with conventional 1DRF scans decreased with UNFOLD. Finally, 2DRF combined with UNFOLD accelerated the 4D flow acquisition 3.5 ± 1.4 fold by reducing the FOV and increasing the effective temporal resolution by 6.7% compared with conventional 1D selective excitation, with 2 k‐space lines per cardiac phase.ConclusionTwo‐dimensional selective excitation combined with UNFOLD allows limiting the FOV to shorten 4D flow scan times and compensates for the loss in temporal resolution with 2DRF (Δt = 64.8 ms) compared with 1DRF (Δt = 43.2 ms), yielding an effective resolution of Δteff = 40.5 ms to enhance peak flow quantification.
7T bone perfusion imaging of the knee using arterial spin labeling MRI
Authors: Li Xiufeng , Johnson Casey P. , Ellermann Jutta 
Published: December 2019

PurposeTo evaluate the feasibility of arterial spin labeling (ASL) imaging of epiphyseal bone marrow in the distal femoral condyle of the knee at 7T MRI.MethodsThe knees of 7 healthy volunteers were imaged with ASL using a 7T whole body MRI scanner and a 28‐channel knee coil. ASL imaging used a flow‐sensitive alternating inversion recovery method for labeling and a single‐shot fast spin echo sequence for image readout. ASL imaging with a single oblique transverse slice was performed at 2 slice positions in the distal femoral condyle. Blood flow was measured in 2 regions of interest: the epiphyseal bone marrow and the overlying patellofemoral cartilage. To analyze perfusion SNR, 200 noise images were also acquired using the same ASL imaging protocol with RF pulses turned off.ResultsKnee bone marrow perfusion imaging was successfully performed with all volunteers. The overall mean of blood flow in the knee bone marrow was 32.90 ± 2.41 mL/100 g/min, and the blood flow was higher at the more distal slice position. We observed significant B0 and inhomogeneities, which need to be addressed in the future to improve the quality of ASL imaging and increase the reliability of knee bone marrow perfusion measurements.ConclusionBone marrow perfusion imaging of the distal femoral condyle is feasible using ASL at 7T. Further technical development is needed to improve the ASL method to overcome existing challenges.
Two solution strategies to improve the computational performance of sequentially linear analysis for quasi‐brittle structures
Authors: Pari M. , Swart W. , van Gijzen M.B. , Hendriks M.A.N. , Rots J.G. 
Published: December 2019

SummarySequentially linear analysis (SLA), an event‐by‐event procedure for finite element (FE) simulation of quasi‐brittle materials, is based on sequentially identifying a critical integration point in the FE model, to reduce its strength and stiffness, and the corresponding critical load multiplier (λcrit), to scale the linear analysis results. In this article, two strategies are proposed to efficiently reuse previous stiffness matrix factorisations and their corresponding solutions in subsequent linear analyses, since the global system of linear equations representing the FE model changes only locally. The first is based on a direct solution method in combination with the Woodbury matrix identity, to compute the inverse of a low‐rank corrected stiffness matrix relatively cheaply. The second is a variation of the traditional incomplete LU preconditioned conjugate gradient method, wherein the preconditioner is the complete factorisation of a previous analysis step's stiffness matrix. For both the approaches, optimal points at which the factorisation is recomputed are determined such that the total analysis time is minimised. Comparison and validation against a traditional parallel direct sparse solver, with regard to a two‐dimensional (2D) and three‐dimensional (3D) benchmark study, illustrates the improved performance of the Woodbury‐based direct solver over its counterparts, especially for large 3D problems.
Simulation of three‐dimensional elastoacoustic wave propagation based on a Discontinuous Galerkin spectral element method
Authors: F. Antonietti Paola , Bonaldi Francesco , Mazzieri Ilario 
Published: December 2019

SummaryIn this article, we present a numerical discretization of the coupled elastoacoustic wave propagation problem based on a discontinuous Galerkin spectral element approach in a three‐dimensional setting. The unknowns of the coupled problem are the displacement field and the velocity potential, in the elastic and the acoustic domains, respectively, thereby resulting in a symmetric formulation. After stating the main theoretical results, we assess the performance of the method by convergence tests carried out on both matching and nonmatching grids, and we simulate realistic scenarios where elastoacoustic coupling occurs. In particular, we consider the case of Scholte waves, the scattering of elastic waves by an underground acoustic cavity, and a problem of marine seismic exploration. Numerical simulations are carried out by means of the code SPEED, available at http://speed.mox.polimi.it.
Nonprofit entrepreneurial orientation: A systematic literature review and conceptual framework
Authors: M. Lacerda Fabrício , D. P. Martens Cristina , M. R. Freitas Henrique 
Published: December 2019

AbstractThe purpose of this study is to propose a set of factors that characterize the manifestation of entrepreneurial orientation (EO) in nonprofit organizations (NPOs), and we performed a systematic review of the literature. Initially, 17 studies were identified in different databases, and after a full reading of the documents that met the objective of this study, we selected and qualitatively analyzed 14 theoretical and empirical studies about EO in the nonprofit context. The studies analyzed allowed us to understand the characteristics of organizational entrepreneurship in NPOs, through the dimensions of innovativeness, proactivity, risk‐taking, autonomy, and competitive aggressiveness, in addition to the reciprocity dimension, which emerged from the literature. By adding reciprocity as the sixth dimension of the EO construct, it was possible to group a set factors related to each dimension which, after being refined, supported the proposition of a conceptual framework for an empirical analysis of entrepreneurial behavior in different contexts of NPOs. This study contributes to the systematization of factors that configure the manifestation of EO in the nonprofit sector, by proposing a conceptual framework entailing six dimensions of EO and propositions for future studies.
Causes of early death and treatment‐related death in newly diagnosed pediatric acute myeloid leukemia: Recent experiences of the Dutch Childhood Oncology Group
Authors: Klein Kim , van Litsenburg Raphaële R.L. , de Haas Valérie , Dors Natasja , van den Heuvel‐Eibrink Marry M. , Knops Rutger R.G. , Tissing Wim J.E. , Versluys Birgitta A. , Zwaan C. Michel , Kaspers Gertjan J.L. 
Published: December 2019

AbstractBackgroundWith the current more effective treatment regimens for pediatric acute myeloid leukemia (AML), research on early death (ED), treatment‐related mortality (TRM), and toxicity becomes increasingly important. The aim of this study was to give an overview of the frequency, clinical features, and risk factors associated with ED and TRM in first complete remission (CR1) during the last three consecutive treatment protocols of the Dutch Childhood Oncology Group (DCOG) between 1998 and 2014.MethodsIncidence and risk factors associated with ED and TRM in CR1 were retrospectively studied in 245 patients treated according to the Dutch ANLL‐97/AML‐12 (n = 118), AML‐15 (n = 60), or DB AML‐01 (n = 67) protocols.ResultsThe incidence of ED was, respectively, 5.1%, 6.7%, and 3.0% excluding deaths before treatment (P = NS), and 7.4%, 11.1%, and 4.4% including deaths before the onset of treatment. Severe underweight at initial diagnosis was significantly associated with more frequent ED. When relapse was included as a competing risk, cumulative incidence of death in CR1 were 5.9%, 5.0%, and 4.6% for ANLL97, AML15, and DB01, respectively (P = NS). The most important cause of TRM included infectious and SCT‐related complications.ConclusionWe report relatively stable rates of ED and TRM in CR1 in the latest completed DCOG protocols for newly diagnosed AML patients. The most important causes of TRM were SCT‐ or infection‐related, warranting further evaluation and awareness.
An application‐oriented roadmap to select polymeric nanocomposites for advanced applications: A review
Authors: Doagou‐Rad Saeed , Islam Aminul , Merca Timea D. 
Published: December 2019

AbstractPolymeric nanocomposites are the materials incorporating nanosized inclusions into the polymer matrixes. The result of the addition of nanoparticles/fibers is a drastic improvement in properties that may include mechanical, electrical, thermal conductivity, or even the acoustical properties. Polymer nanocomposites have spawned huge interest for the development of high‐performance products such as lightweight sensors, thin‐film capacitors, batteries, flame retardant products, biodegradable and biocompatible materials, and so on. The field of polymer nanocomposites has been at the forefront of research in the polymer community for the past few decades and an extremely large number of scientific papers have been published. Nevertheless, application‐oriented guidelines for selecting the ecofriendly nanocomposites for advanced industrial applications are missing in the state of the art. This review article summarizes the current state‐of‐the‐art polymeric nanocomposites, highlighting prominent nanofillers categorized based on their applications, origins, dimensional characteristics, and so on. Each filler type contains a short description of its main feature together with the most relevant and potential applications. To address the global concern about nondegradable wastes, novel green alternatives of each nanofiller type are discussed. Special attention is also given to the biocompatibility properties of the composites. This study provides a state‐of‐the‐art road map to select multifunctional polymeric nanocomposites from huge varieties for advanced industrial applications.
Production of polyacrylonitrile/boehmite nanofibrous composite tubular structures by opposite‐charge electrospinning with enhanced properties from a low‐concentration polymer solution
Authors: Habeeb Salih A. , Rajabi Laleh , Dabirian Farzad 
Published: December 2019

AbstractPolyacrylonitrile (PAN)/boehmite nanofibrous composite tubular structures were fabricated from dilute polymer solutions using an opposite‐charge electrospinning method. The samples were characterized by X‐ray diffraction, Differential scanning calorimetry, scanning electron microscopy, Fourier‐transform infrared spectroscopy, fast Fourier transform, and tensile tests. The presence of boehmite nanoparticles in the electrospun PAN nanofibers prevented bead formation, resulting in uniform fibers with smaller diameters, and improved alignment from low‐concentration PAN polymer solutions. 1 wt% boehmite‐loaded nanofibrous composite tubular structure was selected as the optimal formulation to proceed with the crystallinity and tensile tests, which showed enhanced crystalline properties as well as an abrupt shift in tensile performance. The tensile properties of the nanofiber strongly depended on their crystalline properties. The strong intermolecular forces (hydrogen bonds) between the AlOH groups formed at the surface of boehmite nanoparticles and the polar CN groups along the polymer chains. In addition, the high electrical force between the two tips of the needles in the opposite charge set‐up can contribute to the control of electrical jet deposition instability when using a low‐concentration electrospinning solution, leading to enhanced properties.
Optimal diffuse augmented atomic basis sets for extrapolation of the correlation energy
Authors: Varandas António J. C. , Pansini Fernando N. N. 
Published: December 2019

AbstractWe seek correlation‐consistent diffuse‐augmented double‐zeta and triple‐zeta basis sets that perform optimally in extrapolating the correlation energy to the one‐electron complete basis set limit, denoted oAVXZ and oAV(X + d)Z. The novel basis sets are method‐dependent in that they are trained to perform optimally for the correlation energy at each specific level of theory. They are shown to yield accurate results in calculating both the energy and tensorial properties such as polarizabilities while not significantly altering the Hartree‐Fock energy. Quantitatively, complete basis set limit (CBS)‐/(oAVdZ,oAVtZ)‐extrapolated correlation energies typically outperform, by 3‐ to 5‐fold, the ones calculated with traditional ansatzes of similar flexibility. Attaining energies of CBS/(AVtZ,AVqZ) type or better accuracy, they frequently outperform expensive raw explicitly correlated ones. Promisingly, a limited test on CBS‐extrapolated energies based on conventional basis sets has shown that they compare well even with extrapolated explicitly correlated ones. Calculated atomization and dissociation energies, molecular geometries, ionization potentials, and electron affinities also tend to outperform the ones obtained with traditional Dunning's ansatzes from which the new basis sets have been determined. The method for basis set generation is simple, and there is no reason of principle why the approach could not be adapted for handling other bases in the literature.