bluuebunny/crossref_metadata_2025_split huggingface dataset:
Random walk and non-Gaussianity of the 3D second-quantized Schrödinger–Newton nonlocal soliton
Authors: Conti Claudio 
Published: February 2023

Abstract
Nonlocal quantum fluids emerge as dark-matter models and tools for quantum simulations and technologies. However, strongly nonlinear regimes, like those involving multi-dimensional self-localized solitary waves, are marginally explored for what concerns quantum features. We study the dynamics of 3D+1 solitons in the second-quantized nonlocal nonlinear Schrödinger–Newton equation. We theoretically investigate the quantum diffusion of the soliton center of mass and other parameters, varying the interaction length. 3D+1 simulations of the Ito partial differential equations arising from the positive P-representation of the density matrix validate the theoretical analysis. The numerical results unveil the onset of non-Gaussian statistics of the soliton, which may signal quantum-gravitational effects and be a resource for quantum computing. The non-Gaussianity arises from the interplay between the soliton parameter quantum diffusion and the stable invariant propagation. The fluctuations and the non-Gaussianity are universal effects expected for any nonlocality and dimensionality.
On monogamy and polygamy relations of multipartite systems
Authors: Zhang Xia , Jing Naihuan , Liu Ming , Ma Haitao 
Published: February 2023

Abstract
We study the monogamy and polygamy relations related to quantum correlations for multipartite quantum systems in a unified manner. It is known that any bipartite measure obeys monogamy and polygamy relations for the r-power of the measure. We show in a uniformed manner that the generalized monogamy and polygamy relations are transitive to other powers of the measure in weighted forms We demonstrate that our weighted monogamy and polygamy relations are stronger than recently available relations. Comparisons are given in detailed examples which show that our results are stronger in both situations.
Silicon-on-silica waveguides-based all-optical logic gates at 1.55 μm
Authors: Kotb Amer , Zoiros Kyriakos E , Li Wei 
Published: February 2023

Abstract
The demand for faster and more efficient integrated photonic circuits has prompted the rise of silicon-on-insulator technology. In this paper, silicon-on-silica waveguides have been employed for the all-optical realization of a complete family of logic gates, including XOR, AND, OR, NOT, NOR, NAND and XNOR operated at 1.55 μm. This waveguide consists of three identical slots and six microring resonators, all made of silicon patterned on silica. The principle of operation of these logic gates is based on the constructive and destructive interference induced by the phase difference between the input signals. The gates’ performance is evaluated against the contrast ratio (CR) metric. Compared to existing waveguides, the proposed waveguides achieve higher CRs with a speed as high as 120 Gb s−1.
Free streaming length of axion-like particle after oscillon/I-ball decays
Authors: Imagawa Kaname , Kawasaki Masahiro , Murai Kai , Nakatsuka Hiromasa , Sonomoto Eisuke 
Published: February 2023

Abstract
Axion-like particles (ALPs) are pseudoscalar bosons predicted by string theory.
The ALPs have a shallower potential than a quadratic one, which induces the instability and can form the solitonic object called oscillon/I-ball.
Although the lifetime of oscillons can be very long for some type of potentials, they finally decay until the present.
We perform the numerical lattice simulations to investigate the decay process of oscillons and evaluate the averaged momentum of ALPs emitted from the oscillon decay.
It is found that, if oscillons decay in the early universe, the free-streaming length of ALPs becomes too long to explain the small-scale observations of the matter power spectrum.
We show that oscillons with long lifetimes can change the density fluctuations on small scales, which leads to stringent constraints on the ALP mass and the oscillon lifetime.
Upper limits on the polarized isotropic stochastic gravitational-wave background from advanced LIGO-Virgo's first three observing runs
Authors: Jiang Yang , Huang Qing-Guo 
Published: February 2023

Abstract
Parity violation is expected to generate an asymmetry between the amplitude of left and
right-handed gravitational-wave modes which leads to a circularly polarized stochastic
gravitational-wave background (SGWB). Due to the three independent baselines in the LIGO-Virgo
network, we focus on the amplitude difference in strain power characterized by Stokes' parameters
and do maximum-likelihood estimation to constrain the polarization degree of SGWB. Our results
indicate that there is no evidence for the circularly polarized SGWB in the data. Furthermore, by
modeling the SGWB as a power-law spectrum, we place upper limit on the normalized energy density
Ωgw(25 Hz) < 5.3 × 10-9 at 95% confidence level after marginalizing
over the polarization degree and spectral index.
Decoherence-free subspace and entanglement sudden death of multi-photon polarization states in fiber channels
Authors: Liu Yiwen 
Published: February 2023

Abstract
The construction of quantum networks requires long-distance teleportation of multi-qubit entangled states. Here, we investigate the entanglement dynamics of GHZ and W states in fiber channels. In a fiber channel, the two most important phenomena that affect polarization entanglement are polarization mode dispersion (PMD) and polarization-dependent loss (PDL). We theoretically characterize how PMD and PDL vectors affect three-qubit states. In particular, upon quantifying the entanglement at the output states using concurrence and entanglement witnesses, we reveal the occurrence of entanglement sudden death and the appearance of decoherence-free subspaces in tripartite systems. Finally, we explore the evolution of GHZ and W state with an arbitrary number of photons in a fiber network and discuss the decoherence mechanism of the 4-party cluster state.
Localization of deep brain stimulation trajectories via automatic mapping of microelectrode recordings to MRI
Authors: Rao Akshay T , Chou Kelvin L , Patil Parag G 
Published: February 2023

Abstract

Objective. Suboptimal electrode placement during subthalamic nucleus deep brain stimulation (STN DBS) surgery may arise from several sources, including frame-based targeting errors and intraoperative brain shift. We present a computer algorithm that can accurately localize intraoperative microelectrode recording (MER) tracks on preoperative magnetic resonance imaging (MRI) in real-time, thereby predicting deviation between the surgical plan and the MER trajectories. Approach. Random forest (RF) modeling was used to derive a statistical relationship between electrophysiological features on intraoperative MER and voxel intensity on preoperative T2-weighted MR imaging. This model was integrated into a larger algorithm that can automatically localize intraoperative MER recording tracks on preoperative MRI in real-time. To verify accuracy, targeting error of both the planned intraoperative trajectory (‘planned’) and the algorithm-derived trajectory (‘calculated’) was estimated by measuring deviation from the final DBS lead location on postoperative high-resolution computed tomography (‘actual’). Main results. MR imaging and MERs were obtained from 24 STN DBS implant trajectories. The cross-validated RF model could accurately distinguish between gray and white matter regions along MER trajectories (AUC 0.84). When applying this model within the localization algorithm, the calculated MER trajectory estimate was found to be significantly closer to the actual DBS lead when compared to the planned trajectory recorded during surgery (1.04 mm vs 1.52 mm deviation, p < 0.002), with improvement shown in 19/24 cases (79%). When applying the algorithm to simulated DBS trajectory plans with randomized targeting error, up to 4 mm of error could be resolved to <2 mm on average (p < 0.0001). Significance. This work presents an automated system for intraoperative localization of electrodes during STN DBS surgery. This neuroengineering solution may enhance the accuracy of electrode position estimation, particularly in cases where high-resolution intraoperative imaging is not available.
Filter bank sinc-convolutional network with channel self-attention for high performance motor imagery decoding
Authors: Chen Jiaming , Wang Dan , Yi Weibo , Xu Meng , Tan Xiyue 
Published: February 2023

Abstract

Objective. Motor Imagery Brain-Computer Interface (MI-BCI) is an active Brain-Computer Interface (BCI) paradigm focusing on the identification of motor intention, which is one of the most important non-invasive BCI paradigms. In MI-BCI studies, deep learning-based methods (especially lightweight networks) have attracted more attention in recent years, but the decoding performance still needs further improving. Approach. To solve this problem, we designed a filter bank structure with sinc-convolutional layers for spatio-temporal feature extraction of MI-electroencephalography in four motor rhythms. The Channel Self-Attention method was introduced for feature selection based on both global and local information, so as to build a model called Filter Bank Sinc-convolutional Network with Channel Self-Attention for high performance MI-decoding. Also, we proposed a data augmentation method based on multivariate empirical mode decomposition to improve the generalization capability of the model. Main results. We performed an intra-subject evaluation experiment on unseen data of three open MI datasets. The proposed method achieved mean accuracy of 78.20% (4-class scenario) on BCI Competition IV IIa, 87.34% (2-class scenario) on BCI Competition IV IIb, and 72.03% (2-class scenario) on Open Brain Machine Interface (OpenBMI) dataset, which are significantly higher than those of compared deep learning-based methods by at least 3.05% (

p

= 0.0469), 3.18% (

p

= 0.0371), and 2.27% (

p

= 0.0024) respectively. Significance. This work provides a new option for deep learning-based MI decoding, which can be employed for building BCI systems for motor rehabilitation.
Connections between spatially distant primary language regions strengthen with age during infancy, as revealed by resting-state fNIRS
Authors: Paranawithana Ishara , Mao Darren , McKay Colette M , Wong Yan T 
Published: February 2023

Abstract

Objective. Hearing is an important sensory function that plays a key role in how children learn to speak and develop language skills. Although previous neuroimaging studies have established that much of brain network maturation happens in early childhood, our understanding of the developmental trajectory of language areas is still very limited. We hypothesized that typical development trajectory of language areas in early childhood could be established by analyzing the changes of functional connectivity in normal hearing infants at different ages using functional near-infrared spectroscopy. Approach. Resting-state data were recorded from two bilateral temporal and prefrontal regions associated with language processing by measuring the relative changes of oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) concentrations. Connectivity was calculated using magnitude-squared coherence of channel pairs located in (a) inter-hemispheric homologous and (b) intra-hemispheric brain regions to assess connectivity between homologous regions across hemispheres and two regions of interest in the same hemisphere, respectively. Main results. A linear regression model fitted to the age vs coherence of inter-hemispheric homologous test group revealed a significant coefficient of determination for both HbO (R
2 = 0.216, p = 0.0169) and HbR (R
2 = 0.206, p = 0.0198). A significant coefficient of determination was also found for intra-hemispheric test group for HbO (R
2 = 0.237, p = 0.0117) but not for HbR (R
2 = 0.111, p = 0.0956). Significance. The findings from HbO data suggest that both inter-hemispheric homologous and intra-hemispheric connectivity between primary language regions significantly strengthen with age in the first year of life. Mapping out the developmental trajectory of primary language areas of normal hearing infants as measured by functional connectivity could potentially allow us to better understand the altered connectivity and its effects on language delays in infants with hearing impairments.
Effect of driving pressure and flux rate on red wine nanofiltration
Authors: Lazarova M , Dencheva-Zarkova M , Yankov D , Genova J 
Published: February 2023

Abstract
Red wine contains many bioactive components, such as phenolics, which play a beneficial role on human health and also are responsible for important sensory qualities of wine. Membrane technology offers advantages compared to the conventional methods used for polyphenols extraction in terms of high recovery/removal efficiency, no phase transition and mild operating conditions. In this study, nanofiltration of the native Bulgarian red wine Mavrud was performed. The MaxiMem membrane filtration system employing the nanofiltration membrane Microdyn Nadir™ NP030 P (MWCO 500 Da) was used for this purpose. The effects of the operating parameters (transmembrane pressure and flow rate) on the retention of bioactive compounds in wine were investigated. The phenolic amount of the obtained wine after nanofiltration was evaluated and compared with the data of the original wine. It was found out that the examined nanofiltration membrane can be effectively used for concentration of phenolics in wine. Optimal results with 29 % concentration of the phenolics in the obtained wine were achieved applying two sets of pressure and flow rate, namely 40 bar and 1.2 L/min, and 30 bar and 3 L/min.
Enzyme activity of β-galactosidase immobilized in polyelectrolyte multilayers deposited on corona charged composite substrates
Authors: Grigorov A , Viraneva A , Marudova M , Yovcheva T , Iliev I 
Published: February 2023

Abstract
In the present paper chitosan and xanthan polyelectrolyte multilayers (PEMs) deposited on composite multicomponent poly(D-lactic acid) (PDLA) / poly(ε-caprolactone) (PEC) substrates were investigated. The substrates' melting phenomena and degree of crystallinity were investigated by differential scanning calorimetry (DSC). Based on the melting behaviour it was suggested that PLA and PEC are not miscible at molecular level and no co-crystallization is realized. The substrates obtained were charged in a corona discharge. Positive or negative 5 kV voltages were applied to the corona electrode and 1 kV voltage of the same polarity - to the grid. The normalized surface potential dependences on the storage times were investigated. The results obtained show that the values of the normalized surface potential decay faster for negatively charged substrates. Layer-by-layer (LbL) technique was used for multilayer deposition on the substrates. PEMs with 8 layers were obtained. The enzyme of β-galactosidase was immobilized in the obtained polyelectrolyte multilayers. The enzyme activity of the immobilized enzyme was studied. The experimental results obtained show that the enzyme immobilization in positively charged films have higher activity compared to the negatively charged ones, independently of substrates type.
Effect of nanofiller concentration on its dispersion in a system of liquid crystalline SB(3R)-11 and single walled carbon nanotubes
Authors: Exner Ginka , Marinov Yordan , Veerabhadraswamy Bhyranalyar , Yelamaggad Channabasaveshwar , Rafailov Peter , Georgieva Veselina 
Published: February 2023

Abstract
We report on the concentration dependence of the dispersion of single walled carbon nanotubes, SWCNTs, in a nanocomposite with a recently synthesized ferroelectric and optically active thermotropic liquid crystal ((R,E)-4-(4-((3,7-dimethyloctyl) oxy) styryl) phenyl 4-(undecyloxy)benzoate. Excellent dispersion of the SWCNTs in the concentration range from 0.01 up to 10 wt % was proven by means of differential scanning calorimetry, polarized optical microscopy, and Raman spectroscopy. It is believed to be facilitated by the formation of core-shell fibres, consisting of liquid crystal decorated SWCNTs, yet in the solution state. The fibres are maintained after the solvent evaporation and so the aggregation at elevated temperatures is prevented. The preservation of the liquid crystalline behaviour in all investigated cases can be considered as an additional benefit.
Crosslinked chitosan-based particles obtained by water-in-oil emulsion technique
Authors: Milenkova Sofia , Marudova Maria , Zahariev Nikolay , Yovcheva Temenuzhka , Pilicheva Bissera 
Published: February 2023

Abstract
Particles based on emulsified chitosan in oil phase have been reported in the present study. Sodium Tripolyphosphate (NaTPP) was introduced to them as a crosslinker and its effect on their properties was examined. Laser diffraction technique showed that the obtained structures are micronsized particles with single modal distribution. Optical microscopy has confirmed their size range, together with the fact that their shape is regular and spherical. Swelling studies in simulated saliva conditions (pH = 6.8) has shown a relation between the crosslinking degree of the particles and cycles of swelling and dissolution at different rates. Mucoadhesion test confirmed their potential as delivery systems through a mucosal route and showed dependence of the mucoadhesion properties upon the free amino groups left onto the chitosan chains.
Chitosan/grapeseed oil multicomponent edible films - design and properties
Authors: Gechev Biser , Zsivanovits Gabor , Iliev Angel , Marudova Maria 
Published: February 2023

Abstract
Physical and antioxidant properties of edible chitosan films, formed by casting method, were investigated. The films were loaded with grapeseed oil (GsO), which is a strong antioxidant, contains vitamin E and protects human cells against cancer. The mechanical puncture characteristics, thickness, water uptake, barrier, and antioxidant (DPPH assay) properties of the films were investigated. The results showed that the addition of GsO to chitosan film accelerated the oxygen and water vapor exchange and reduced the strength of the films. The increased antioxidant activity of the films is a prerequisite for extending the shelf life of food products packaged in them.
Polarised line shape calculations for conditions encountered in stellar magnetic atmospheres
Authors: Giustolisi L , Leone F , Stift M , Giarrusso M , Rosato J 
Published: February 2023

Abstract
We present new investigations into spectral line shapes under conditions typical for magnetic stellar atmospheres. Our method for simulating line profiles takes into account the coupled Zeeman and Stark effects. The calculations presented here will ultimately help to correctly model the Stokes parameters of peculiar stellar objects such as the Magnetic White Dwarfs (MWDs), retrieving their magnetic field geometries from spectropolarimetric observations. For the magnetic analysis of this class of stars, in general only Stokes I profiles as a function of rotational phase have been used in the past, in a very few cases, also Stokes V. The present improved simulations of the full Stokes parameters are expected to provide a powerful tool for the analysis of strong magnetic fields like those found in the MWDs.
Review of recent advances in the analytical theory of Stark broadening of spectral lines in plasmas: applications to laboratory discharges and astrophysical plasmas
Authors: Oks E. , Dalimier E. , Angelo P. , Sanders P. 
Published: February 2023

Abstract
We present an overview of latest advances in the analytical theory of Stark broadening of spectral lines and their applications to various types of laboratory and astrophysical plasmas. They include: 1) in-depth study of intra-Stark spectroscopy in the x-ray range in relativistic laser-plasma interactions; 2) effect of diamagnetism on the number of observable hydrogen lines in plasmas; 3) influence of magnetic-field-caused modifications of trajectories of plasma electrons on the width of hydrogen/deuterium spectral lines: applications to white dwarfs; 4) Stark broadening of hydrogen/deuterium spectral lines by a relativistic electron beam: analytical results and applications to magnetic fusion; 5) counterintuitive dependence of the dynamical Stark width of hydrogenic spectral lines on the electron density.
Distinguishing cospectral quantum graphs by scattering
Authors: Mugnolo Delio , Pivovarchik Vyacheslav 
Published: February 2023

Abstract
We propose a simple method for resolution of cospectrality of Schrödinger operators on metric graphs. Our approach consists of attaching a lead to them and comparing the S-functions of the corresponding scattering problems on these (non-compact) graphs. We show that in several cases—including general graphs on at most six vertices, general trees on at most nine vertices, and general fuzzy balls—eigenvalues and scattering data are together sufficient to distinguish cospectral metric graphs.
Validation of the fractional exhaled breath temperature measurement: reference values
Authors: Huljev Šipoš Ivana , Šipoš Kristijan , Steiner Justinija , Grubić Rotkvić Petra , Ljubičić Đivo , Šola Ana Marija , Lozo Vukovac Emilija , Kereš Tatjana , Plavec Davor 
Published: February 2023

Abstract
Exhaled breath temperature (EBT) is a known biomarker of inflammation and airways blood flow. As opposed to previous studies, we were able to measure temperature of separate fractions of exhaled breath (fEBT) (those from the peripheral and central airways). The aim was to validate the fEBT measurement method to determine the reference values and the influence of endogenous and exogenous factors on fEBT in healthy subjects. This cross-sectional study included 55 healthy adults in whom fEBT was repeatedly measured, two days in a row, using a FractAir® device. Also, basal metabolic rate, level of physical activity, distance from the main road, outdoor and ambient temperature, air pressure and humidity, haematology and inflammation markers, lung function, cumulative EBT and body temperature at characteristic points on the body were measured. The results showed that fEBT from central airways was lower compared to fEBT from the periphery and that fEBTs were not related to body temperature (p > 0.05 for all). We also showed repeatability of fEBT measurements for two consecutive days. All EBT fractions correlated significantly with ambient temperature (<0.01). No associations of fEBT with other personal and external factors were found using multivariate analysis. At room temperature of 22 °C, the physiological temperature values of the first fraction were 23.481 ± 3.150 °C, the second fraction 26.114 ± 4.024 °C and the third fraction 28.216 ± 3.321 °C. The proposed reference values represent the first part of validation of fEBT as the method for the use in clinical practice.