bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonlinear electrical transport in Fe3O4-decorated graphene nanoplatelets
Authors: Jaiswar Rajkumar , Mederos-Henry Francisco , Hermans Sophie , Raskin Jean-Pierre , Huynen Isabelle 
Published: October 2020

Abstract
This paper investigates the nonlinear properties of graphene nanoplatelets (GNPs), decorated with Fe3O4 magnetic nanoparticles (MaNPs). Nanocomposite MaNP/GNP samples were prepared by a solvothermal method with three different MaNP loading concentrations of 17 wt%, 28 wt% and 40 wt%, and deposited on a metallic interdigitated electrode (IDE). Three different models are proposed to assess measurements, with the objective to explain the electronic transport in the nanocomposites. At first, a thermionic transport model is proposed to fit the DC nonlinear current–voltage characteristics for the three concentrations. It is observed that the barrier height decreases to 0.312, 0.310 and 0.281 eV, following a decrease in the MaNP loading. A second model, dynamic random resistor network (DRRN) further shows that the impedance of IDE increases following the decreasing MaNP loading rate, 40 wt% > 28 wt% > 17 wt%, and that charge transport takes place through a resistor–capacitor (RC) rectifying percolating network. Finally, impedance spectroscopy performed at different applied DC biases shows that a constant phase element (CPE) is necessary in the equivalent circuit in order to fit the Cole–Cole plot AC response of the IDE, instead of the classical parallel RC circuit. The presence of the CPE confirms the hypothesis of random phenomena occurring in the transport according to the DRRN model. CPE is associated with a spatial distribution of different RC circuits, due to disorderness that arises from inhomogeneities in the Fe3O4–GNP samples.
Magnetism and stability of all primitive stacking patterns in bilayer chromium trihalides
Authors: Gibertini Marco 
Published: October 2020

Abstract
Chromium trihalides, CrX3 (with X = Cl, Br, I), are a family of layered magnetic materials that can be easily exfoliated to provide ferromagnetic monolayers. When two layers are stacked together to form a bilayer the interlayer exchange coupling can be either ferromagnetic or antiferromagnetic depending on the stacking sequence. Here we combine crystallographic arguments based on the close-packing condition with first-principles simulations to enumerate all possible stacking patterns in CrX3 bilayers that preserve the spatial periodicity of each layer. We recover all configurations observed in bulk crystals and disclose stacking sequences with no bulk counterpart where the two layers have opposite chirality. Stacking sequences are ranked according to their relative stability and a preferential interlayer magnetic ordering is assigned to each of them. Simulations provide a consistent picture to frame all current experimental observations on bulk and exfoliated CrX3 crystals, with interesting implications for future measurements, including synthetic bilayers with non-standard stacking patterns.
Magnetic, magnetoresistive and low-frequency noise properties of tunnel magnetoresistance sensor devices with amorphous CoFeBTa soft magnetic layers
Authors: Rasly Mahmoud , Nakatani Tomoya , Li Jiangnan , Sepehri-Amin Hossein , Sukegawa Hiroaki , Sakuraba Yuya 
Published: October 2020

Abstract
Magnetic field sensors using the tunnel magnetoresistance (TMR) effect require linear resistance–magnetic field (R–H) response curves with small hysteresis, for which the soft magnetic property of the free layer (FL) is critical. In this work, we investigated amorphous CoFeBTa (CFBT) as a soft magnetic layer of the FL of CoFeB/MgO/CoFeB-based magnetic tunnel junctions in view of magnetic, TMR, and low-frequency noise properties. A two-step annealing process enabled an orthogonal magnetization configuration between the FL and the reference layer, by which linear R–H curves with small hysteresis were realized. The change in the shape of the R–H curve depending on annealing temperature is explained by the Stoner–Wohlfarth model. The highest TMR ratio of ∼160% and sensitivity of ∼70%/mT were obtained with a CFBT (20 nm)/Ta (0.3 nm)/CoFeB (3 nm) FL. The noise of the TMR devices are dominated by 1/f noise below ∼10 kHz in frequency, which limits the detectivity (D) of the magnetic field of the sensor. The sensor devices patterned to 50 µm diameter circular shapes showed a minimum D of ∼2 nT/

Hz

at 10 Hz, which is superior to the previously reported values for the TMR sensors with NiFe soft magnetic layers.
3D growth of silicon nanowires under pure hydrogen plasma at low temperature (250 °C)
Authors: Yang Kai , Coulon Nathalie , Salaun Anne Claire , Pichon Laurent 
Published: October 2020

Abstract
The synthesis of silicon nanowires (SiNWs) is carried out at 250 °C under pure hydrogen plasma from monocrsytalline silicon substrates or amorphous silicon thin film, using indium as a catalyst. Studies have been carried out in function of the duration of the hydrogen plasma. The results showed a growth of smooth surface nanowire arrays (diameter 100 nm, length 500 nm) from an indium thickness of 20 nm and a hydrogen plasma duration of 30 min. The growth of nanowires for longer hydrogen plasma durations has led to SiNWs with larger diameters and rougher surfaces, revealing the onset of secondary nanowire growth on these surfaces, probably due to the presence of indium residues. The results present a new procedure for the 3D solid liquid solid growth mode of SiNWs.
Complex temperature dependence of coherent and incoherent lattice thermal transport in superlattices
Authors: Chakraborty Pranay , Chiu Isaac Armstrong , Ma Tengfei , Wang Yan 
Published: October 2020

Abstract
Currently, it is still unclear how and to what extent a change in temperature impacts the relative contributions of coherent and incoherent phonons to thermal transport in superlattices. Some seemingly conflicting computational and experimental observations of the temperature dependence of lattice thermal conductivity make the coherent–incoherent thermal transport behaviors in superlattices even more elusive. In this work, we demonstrate that incoherent phonon contribution to thermal transport in superlattices increases as the temperature increases due to elevated inelastic interfacial transmission. On the other hand, the coherent phonon contribution decreases at higher temperatures due to elevated anharmonic scattering. The competition between these two conflicting mechanisms can lead to different trends of lattice thermal conductivity as temperature increases, i.e. increasing, decreasing, or non-monotonic. Finally, we demonstrate that the neural network-based machine learning model can well capture the coherent–incoherent transition of lattice thermal transport in the superlattice, which can greatly aid the understanding and optimization of thermal transport properties of superlattices.
Synchronization in adaptive Kuramoto oscillators for power grids with dynamic voltages
Authors: Li Zhuchun , Zhao Xiaoxue 
Published: October 2020

Abstract
In this paper we are concerned with a coupled system of Kuramoto oscillators for power grids with dynamic voltages. Among various models describing the dynamics of synchronous generators, analytic results are available mainly for the second-order model with constant voltages which describes only the dynamics of rotor angles. It is known that two of the most important forms for power system stability are rotor angle stability and voltage stability. Schmietendorf et al (2014 Eur. Phys. J.
223 2577–2592) derived a model of adaptive Kuramoto oscillators for the power grids with dynamic voltages and carried out some numerical studies. In this model, the transient dynamics of voltages is incorporated and the voltage dynamics could be considered together with rotor angle dynamics. In this article, we will consider this model and derive some analytic results for the synchronization of phase angles and stabilization of voltages. We will find a region of attraction for a class of steady states which is explicitly expressed in the parameters of system.
Thresholds for one-parameter families of affine iterated function systems*
Authors: Vince Andrew 
Published: October 2020

Abstract
This paper examines thresholds for certain properties of the attractor of a general one-parameter affine family of iterated functions systems. As the parameter increases, the iterated function system becomes less contractive, and the attractor evolves. Thresholds are studied for the following properties: the existence of an attractor, the connectivity of the attractor, and the existence of non-empty interior of the attractor. Also discussed are transition phenomena between existence and non-existence of an attractor.
Floer homology in the cotangent bundle of a closed Finsler manifold and noncontractible periodic orbits
Authors: Gong Wenmin , Xue Jinxin 
Published: October 2020

Abstract
We show that the existence of noncontractible periodic orbits for compactly supported time-dependent Hamiltonian on the disk cotangent bundle of a Finsler manifold provided that the Hamiltonian is sufficiently large over the zero section. We generalize the Biran–Polterovich–Salamon capacities and earlier constructions of Weber (2006 Duke Math. J.
133 527–568) and other authors Biran et al (2003 Duke Math. J.
119 65–118) to the Finsler setting. We then obtain a number of applications including: (1) generalizing the main theorem of Xue (2017 J. Symplectic Geom.
15 905–936) to the Lie group setting, (2) preservation of minimal Finsler length of closed geodesics in any given free homotopy class by symplectomorphisms, (3) existence of periodic orbits for Hamiltonian systems separating two Lagrangian submanifolds, (4) existence of periodic orbits for Hamiltonians on noncompact domains, (5) existence of periodic orbits for Lorentzian Hamiltonian in higher dimensional case, (6) partial solution to a conjecture of Kawasaki (2016 Heavy subsets and non-contractible trajectories (arXiv:1606.01964)), (7) results on squeezing/nonsqueezing theorem on torus cotangent bundles, etc.
Detection of subjects with ischemic heart disease by using machine learning technique based on heart rate total variability parameters
Authors: Accardo Agostino , Silveri Giulia , Merlo Marco , Restivo Luca , Ajčević Miloš , Sinagra Gianfranco 
Published: October 2020

Abstract

Objective: Ischemic heart disease (IHD), in its chronic stable form, is a subtle pathology due to its silent behavior before developing in unstable angina, myocardial infarction or sudden cardiac death. The clinical assessment is based on typical symptoms and finally confirmed, invasively, by coronary angiography. Recently, heart rate variability (HRV) analysis as well as some machine learning algorithms like artificial neural networks (ANNs) were used to identify cardiovascular arrhythmias and, only in few cases, to classify IHD segments in a limited number of subjects. The goal of this study was the identification of the ANN structure and the HRV parameters producing the best performance to identify IHD patients in a non-invasive way, validating the results on a large sample of subjects. Moreover, we examined the influence of a clinical non-invasive parameter, the left ventricular ejection fraction (LVEF), on the classification performance. Approach: To this aim, we extracted several linear and non-linear parameters from 24 h RR signal, considering both normal and ectopic beats (heart rate total variability), of 251 normal and 245 IHD subjects, matched by age and gender. ANNs using several different combinations of these parameters together with age and gender were tested. For each ANN, we varied the number of hidden neurons from 2 to 7 and simulated 100 times, changing randomly the training and test dataset. Main results: The HRTV parameters showed significant greater variability in IHD than in normal subjects. The ANN applied to mean RR, LF, LF/HF, beta exponent, SD2 together with age and gender reached a maximum accuracy of 71.8% and, by adding as input LVEF, an accuracy of 79.8%. Significance: The study provides a deep insight into how a combination of some HRTV parameters and LVEF could be exploited to reliably detect the presence of subjects affected by IHD.
Detection of coronary artery disease using multi-modal feature fusion and hybrid feature selection
Authors: Zhang Huan , Wang Xinpei , Liu Changchun , Liu Yuanyuan , Li Peng , Yao Lianke , Li Han , Wang Jikuo , Jiao Yu 
Published: October 2020

Abstract

Objective: Coronary artery disease (CAD) is a common fatal disease. At present, an accurate method to screen CAD is urgently needed. This study aims to provide optimal detection models for suspected CAD detection according to the differences in medical conditions, so as to assist physicians to make accurate judgments on suspected CAD patients. Approach: Electrocardiogram (ECG) and phonocardiogram (PCG) signals of 32 CAD patients and 30 patients with chest pain and normal coronary angiograms (CPNCA) were simultaneously collected for this paper. For each subject, the ECG and PCG multi-domain features were extracted, and the results of Holter monitoring, echocardiography (ECHO), and biomarker levels (BIO) were obtained to construct a multi-modal feature set. Then, a hybrid feature selection (HFS) method was developed using mutual information, recursive feature elimination, random forest, and weight of support vector machine to obtain the optimal feature subset. A support vector machine with nested cross-validation was used for classification. Main results: Results showed that the Holter model achieved the best performance as a single-modal feature model with an accuracy of 82.67%. In terms of multi-modal feature models, PCG-Holter, PCG-Holter-ECHO, PCG-Holter-ECHO-BIO, and ECG-PCG-Holter-ECHO-BIO were the optimal bimodal, three-modal, four-modal, and five-modal models, with accuracies of 90.38%, 91.92%, 95.25%, and 96.67%, respectively. Among them, the ECG-PCG-Holter-ECHO-BIO model, which was constructed by combining ECG and PCG signals features with Holter, ECHO, and BIO examination results, achieved the best classification results with an average accuracy, sensitivity, specificity, and F1-measure of 96.67%, 96.67%, 96.67%, and 96.64%, respectively. Significance: The study indicated that multi-modal feature fusion and HFS can obtain more effective information for CAD detection and provide a reference for physicians to diagnose CAD patients.
Donor-acceptor nature of orange photoluminescence in AlN
Authors: Aleksandrov Ivan A , Malin Timur V , Milakhin Denis S , Ber Boris Ya , Kazantsev Dmitrii Yu , Zhuravlev Konstantin S 
Published: October 2020

Abstract
Recombination dynamics, photoluminescence and photoluminescence excitation spectra have been investigated for 1.9 eV photoluminescence band in AlN in the temperature range of 5–650 K. The recombination dynamics for the 1.9 eV photoluminescence band has been described by a model of donor-acceptor recombination with taking into account a broadening due to electron coupling with local lattice vibrations of a deep level defect. The experimental results have been compared with density functional theory calculations of luminescence peak energies and line shapes of band to defect and donor-acceptor transitions, and possible origin of the orange photoluminescence band in AlN has been discussed.
Adaptive global weight window generator based on particles density uniformity for Monte Carlo particles transport simulation
Authors: He Peng , Song Jing , Sun Guangyao , Zhang Shu , Hao Lijuan , Wu Bin , Hu Liqin , Wu Yican , Team FDS 
Published: October 2020

Abstract
Variance reduction techniques are necessary for the Monte Carlo (MC) calculations in which obtaining a detailed flux distribution for a large and complex model is required. A new method for generating mesh weight window (WW) parameters is presented, named global weight window generator (GWWG). In the method, MC calculation is performed to generate the importance of each mesh voxel in the user-set region, and then the corresponding WW parameters are obtained. The importance is related to whether the simulated particles can be uniformly transported to each mesh voxel, which is called particles density uniformity. The GWWG method does not rely on user’s design experience and can significantly improve the calculation efficiency. The tests for this method have been conducted on ITER reference neutronics models. In the calculation of ITER C-Lite model, the FoM was improved comparing to the analog FoM by the factor of 637.4.
Generation of rotating multi-vortex laser beams
Authors: Krasnoshchekov Ye A , Yaparov V V , Taranenko V B 
Published: October 2020

Abstract
We study transverse dynamics of the optical field, generated in a single-frequency laser of moderate Fresnel number. The existence of steadily rotating vortex clusters generated spontaneously in laser with degenerate in frequency cavity is demonstrated numerically and experimentally in laser-like two-wave-mixing photorefractive oscillator with plane-mirror cavity and controlled aperture. The observed rotational dynamics of two-, three- and four-vortex clusters is explained within the framework of the general nonlinear pattern forming model.
Quality of Anatomic Staging of Breast Carcinoma in Hospitals in the United States, With Focus on Measurement of Tumor Dimension
Authors: Wu Dolly Y , Spangler Ann E , de Hoyos Alberto , Vo Dat T , Seiler Stephen J 
Published: October 2020

Abstract

Objectives
We investigated the accuracy of clinical breast carcinoma anatomic staging and the greatest tumor dimension measurements.

Methods
We compared clinical stage and greatest dimension values with the pathologic reference standard values using 57,747 cases from the 2016 US National Cancer Institute Surveillance, Epidemiology, and End Results program who were treated by surgical resection without prior neoadjuvant therapy.

Results
Agreement for clinical vs pathologic anatomic TNM group stage, overall, is 74.3% ± 0.4%. Lymph node N staging overall agrees very well (85.1% ± 0.4%). Based on tumor dimension and location, T staging has an agreement of only 64.2% ± 0.4%, worsening to 55% without carcinoma in situ (Tis) cases. In approximately 25% of cases, pathologic T stage is higher than clinical T stage. The mean difference in the greatest dimension is 1.36 ± 9.59 mm with pathologic values being generally larger than clinical values; pathologic and clinical measurements correlate well. T-stage disagreement is associated with histology, tumor grade, tumor size, N stage, patient age, periodic biases in tumor size measurements, and overuse of family T-stage categories. Pathologic measurement biases include rounding and specimen-slicing intervals.

Conclusions
Clinical and pathologic T-staging values agree only moderately. Pathologists face challenges in increasing the precision of gross tumor measurements, with the goal of improving the accuracy of clinical T staging and measurement.
Temporal Dynamics and Neuronal Specificity of Grin3a Expression in the Mouse Forebrain
Authors: Murillo Alvaro , Navarro Ana I , Puelles Eduardo , Zhang Yajun , Petros Timothy J , Pérez-Otaño Isabel 
Published: October 2020

Abstract
GluN3A subunits endow N-Methyl-D-Aspartate receptors (NMDARs) with unique biophysical, trafficking, and signaling properties. GluN3A-NMDARs are typically expressed during postnatal development, when they are thought to gate the refinement of neural circuits by inhibiting synapse maturation, and stabilization. Recent work suggests that GluN3A also operates in adult brains to control a variety of behaviors, yet a full spatiotemporal characterization of GluN3A expression is lacking. Here, we conducted a systematic analysis of Grin3a (gene encoding mouse GluN3A) mRNA expression in the mouse brain by combining high-sensitivity colorimetric and fluorescence in situ hybridization with labeling for neuronal subtypes. We find that, while Grin3a mRNA expression peaks postnatally, significant levels are retained into adulthood in specific brain regions such as the amygdala, medial habenula, association cortices, and high-order thalamic nuclei. The time-course of emergence and down-regulation of Grin3a expression varies across brain region, cortical layer of residence, and sensory modality, in a pattern that correlates with previously reported hierarchical gradients of brain maturation and functional specialization. Grin3a is expressed in both excitatory and inhibitory neurons, with strong mRNA levels being a distinguishing feature of somatostatin interneurons. Our study provides a comprehensive map of Grin3a distribution across the murine lifespan and paves the way for dissecting the diverse functions of GluN3A in health and disease.
Biomarker Research and Development for Coronavirus Disease 2019 (COVID-19): European Medical Research Infrastructures Call for Global Coordination
Authors: Oldoni Emanuela , van Gool Alain , García Bermejo Laura , Scherer Andreas , Mayrhofer Michaela Th , Florindi Francesco , Demotes Jacques , Kubiak Christine , Fauvel Anne-Charlotte , Bietrix Florence , Ussi Anton , Andreu Antonio L 
Published: October 2020

Abstract
An effective response to the coronavirus disease 2019 (COVID-19) pandemic requires a better understanding of the biology of the infection and the identification of validated biomarker profiles that would increase the availability, accuracy, and speed of COVID-19 testing. Here, we describe the strategic objectives and action lines of the European Alliance of Medical Research Infrastructures (AMRI), established to improve the research process and tackle challenges related to diagnostic tests and biomarker development. Recommendations include: the creation of a European taskforce for validation of novel diagnostic products, the definition and promotion of criteria for COVID-19 samples biobanking, the identification and validation of biomarkers as clinical endpoints for clinical trials, and the definition of immune biomarker signatures at different stages of the disease. An effective management of the COVID-19 pandemic is possible only if there is a high level of knowledge and coordination between the public and private sectors within a robust quality framework.
Specific Redistribution of Severe Acute Respiratory Syndrome Coronavirus 2 Variants in the Respiratory System and Intestinal Tract
Authors: Du Pengcheng , Song Chuan , Li Rui , Song Yangzi , Li Jiarui , Ding Nan , Zhang Ju , Song Rui , Han Junyan , Gao Guiju , Yue Jinglin , Duan Ang , Huang Yanyi , An Jing , Wang Jianbin , Zhang Fujie , Chen Chen , Zeng Hui 
Published: October 2020

Abstract
Intrahost analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomic sequences identified 2 viral haplotypes comprised of 3 genetically linked mutations from the respiratory and intestinal tracts of a patient with coronavirus disease 2019. Spatiotemporal data suggest that this patient initially had dual infection of 2 SARS-CoV-2 variants, which subsequently redistributed into the 2 systems.