bluuebunny/crossref_metadata_2025_split huggingface dataset:
From 12 to 1 ECG lead: multiple cardiac condition detection mixing a hybrid machine learning approach with a one-versus-rest classification strategy
Authors: Jiménez-Serrano Santiago , Rodrigo Miguel , Calvo Conrado J , Millet José , Castells Francisco 
Published: May 2022

Abstract

Objective. Detecting different cardiac diseases using a single or reduced number of leads is still challenging. This work aims to provide and validate an automated method able to classify ECG recordings. Performance using complete 12-lead systems, reduced lead sets, and single-lead ECGs is evaluated and compared. Approach. Seven different databases with 12-lead ECGs were provided during the PhysioNet/Computing in Cardiology Challenge 2021, where 88 253 annotated samples associated with none, one, or several cardiac conditions among 26 different classes were released for training, whereas 42 896 hidden samples were used for testing. After signal preprocessing, 81 features per ECG-lead were extracted, mainly based on heart rate variability, QRST patterns and spectral domain. Next, a One-versus-Rest classification approach made of independent binary classifiers for each cardiac condition was trained. This strategy allowed each ECG to be classified as belonging to none, one or several classes. For each class, a classification model among two binary supervised classifiers and one hybrid unsupervised-supervised classification system was selected. Finally, we performed a 3-fold cross-validation to assess the system’s performance. Main results. Our classifiers received scores of 0.39, 0.38, 0.39, 0.38, and 0.37 for the 12, 6, 4, 3 and 2-lead versions of the hidden test set with the Challenge evaluation metric (

C
M

). Also, we obtained a mean

G

-score of 0.80, 0.78, 0.79, 0.79, 0.77 and 0.74 for the 12, 6, 4, 3, 2 and 1-lead subsets with the public training set during our 3-fold cross-validation. Significance. We proposed and tested a machine learning approach focused on flexibility for identifying multiple cardiac conditions using one or more ECG leads. Our minimal-lead approach may be beneficial for novel portable or wearable ECG devices used as screening tools, as it can also detect multiple and concurrent cardiac conditions.
On the power and efficiency of Ni2MnGa magnetic shape memory alloy power harvesters
Authors: D’Silva Glen J , Feigenbaum Heidi P , Ciocanel Constantin 
Published: May 2022

Abstract
The martensite variant reorientation in Ni2MnGa magnetic shape memory alloys (MSMAs) causes a change in their bulk magnetization, that can be harvested into useful voltage/power by means of a pick-up coil. The coil may be placed directly surrounding an MSMA element or to the side of the MSMA element wrapped around a magnetic core. This paper reports new power harvesting data generated with a bi-axial magnetic field and a surrounding coil and full strain field data for an MSMA subject to load similar to what is seen during power harvesting, then compares the performance of MSMA-based power harvesters with different designs to determine which give the best output. For this comparison, we provide a framework for evaluating the performance of MSMA-based power harvesters reported in the literature. This framework involves normalizing the results to the design characteristics of the respective harvesters, i.e. number of turns of the pickup coil, cross-sectional area of the pickup coil, frequency of excitation, and sample size, to allow for a direct comparison of power harvesters’ output. Results show that power harvesting with the bi-axial field and a surrounding coil does not generate as much power as previously thought. The strain maps reveal the potential for perpendicular twin boundaries that block each other’s motion limiting variant reorientation and correspondingly the harvester’s power output. The paper concludes that the largest change in magnetic flux density, which is the driver for power harvesting, occurs in the side coil setup with an optimized magnetic circuit and it recommends using this configuration for future MSMA-based power harvester designs for maximum power output.
Significant enhancement of critical current density in H+-intercalated FeSe single crystal
Authors: Meng Yan , Wei Wei , Xing Xiangzhuo , Yi Xiaolei , Zhou Nan , Zhang Yufeng , Liu Wenhui , Sun Yue , Shi Zhixiang 
Published: May 2022

Abstract
Superconducting transition temperature (T
c) and critical current density (J
c) are two key factors that are not only crucial for probing high temperature superconducting mechanism, but also for practical applications. The simple crystal structure of FeSe is very favorable for the fabrication of thin films and wires, but its application is limited by the relatively low T
c and small J
c. Previous studies have found that the T
c of FeSe can be significantly enhanced over 40 K by using protonation method. Here, we present a systematic study of J
c and vortex properties of H+-intercalated FeSe (H
x
-FeSe) single crystals. The value of J
c for H
x
-FeSe single crystal is significantly enhanced, exceeding 1.3 × 106 A cm−2 at 4 K, which is more than two orders of magnitude larger than 1.1 × 104 A cm−2 of pristine FeSe. The vortex pinning mechanism of H
x
-FeSe is found to be surface pinning, which is different from the dominant strong point-like pinning in pristine FeSe. Moreover, the systematic study of the vortex phase transition and the underlying mechanism provides a wealth of information for the vortex phase diagram of H
x
-FeSe single crystal. Our results confirm that the introduction of H+ intercalations into FeSe not only enhance the T
c but also significantly increases the value of J
c, which is favorable for practical applications.
Optimal Prediction of Atmospheric Turbulence by Means of the Weather Research and Forecasting Model
Authors: Rafalimanana Alohotsy , Giordano Christophe , Ziad Aziz , Aristidi Eric 
Published: May 2022

Abstract
The performance of ground-based astronomical observations and free-space optical communication (FSOC) systems suffers from atmospheric turbulence and meteorological conditions. The a priori knowledge of atmospheric conditions several hours before observations allows the programming of astronomical observations (flexible scheduling) to be optimized. In this paper, we present a prediction study based on the Weather Research and Forecasting (WRF) model. It allows the prediction and characterization of a useful set of meteorological parameters relevant to atmospheric physics (e.g., pressure, temperature, relative humidity, wind speed, and direction). Predicted parameters are then injected into an optical turbulence (OT) model to compute the refractive index structure constant C

n

2. We performed sets of simulations for Cerro Pachon Observatory in Chile, using the data from the National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (CFSR). The main goal is to quantify how accurately numerical weather prediction models can reproduce conditions over the complex terrain of the Cerro Pachon area. In order to produce a reliable forecast, meteorological prognostic skills need accurate representations of the physical parameterization options. Three widely used Planetary Boundary Layer (PBL) schemes and two Land Surface Models (LSM) were tested, analyzed, and compared in order to find the optimal WRF configuration. Predictions are compared to in situ measurements coming from balloon-borne radiosoundings. It is determined that the predicted C

n

2 are in good agreement with the radiosoundings measurements with a mean relative error (MRE) under 6.4% at all altitudes when using balloon measurements to deduce some parameters such as the outer scale of turbulence L
0, which is used in the OT model. For a fully operational prediction, the MREs between the predictions and the measurements range from 1.4% to 8% according to the different ways to estimate the L
0 profiles. Seasonal statistics are also presented for different meteorological and turbulence parameters.
Non-destructive assessment of milk quality using pulsed UV photoacoustic, fluorescence and near FTIR spectroscopy
Authors: Khosroshahi Mohammad E , Patel Yesha , Woll-Morison Vaughan 
Published: May 2022

Abstract
The work describes the application of photoacoustic (PA), fluorescence spectroscopy, and Fourier transform near-infrared spectroscopy as non-destructive optical techniques to examine the quality of milk. The amplitude of the acoustic wave was linearly proportional to the absorbed fluence. The acoustic velocity and the fluence threshold for onset of non-linearity were decreased as the fat % increased. Initially, the PA pressure was increased with fluence but it exhibited non-linearity and occurred earlier i.e. faster as the fat % was increased. The peak pressures of 120, 160, and 180 kPa were determined for 1%, 2%, and 3.5% respectively. The corresponding acoustic transient times of 0.5, 0.44, and 0.36 µs were calculated for 1%, 2%, and 3.5% milk respectively. The absorption coefficient of milk samples was determined using the pressure-fluence slope and Grüneisen constant, which increased with fat %. The bandwidths between 350–450 nm and 450–550 nm correspond to tryptophan or valine, and Methionine amino acids respectively, and the peak at ≈315 nm is thought to be due to tyrosine. The fluorescence intensity of the sample day 1 (D1-open) decreased with time more significantly due to variations in the environmental condition. The bands between 4000 and 4500 cm−1 correspond to CH-stretch, and day 4 (D4-closed) showed the highest peak amplitudes compared to the others. Combination of N–H and O–H stretch was mainly observed between 4500 and 5000 cm−1, and the bands at 4581, 4655 cm−1 in fresh sample disappeared in D1-open and D1-closed. New bands of 4717, 4792, and 4829 cm−1 were observed.
Preclinical safety study of a fully implantable, sub-scalp ring electrode array for long-term EEG recordings
Authors: Benovitski Yuri B , Lai Alan , Saunders Alexia , McGowan Ceara C , Burns Owen , Nayagam David A X , Millard Rodney , Harrison Mark , Rathbone Graeme D , Williams Richard A , May Clive N , Murphy Michael , D’Souza Wendyl J , Cook Mark J , Williams Chris E 
Published: May 2022

Abstract

Objective. Long-term electroencephalogram (EEG) recordings can aid diagnosis and management of various neurological conditions such as epilepsy. In this study we characterize the safety and stability of a clinical grade ring electrode arrays by analyzing EEG recordings, fluoroscopy, and computed tomography (CT) imaging with long-term implantation and histopathological tissue response. Approach. Seven animals were chronically implanted with EEG recording array consisting of four electrode contacts. Recordings were made bilaterally using a bipolar longitudinal montage. The array was connected to a fully implantable micro-processor controlled electronic device with two low-noise differential amplifiers and a transmitter-receiver coil. An external wearable was used to power, communicate with the implant via an inductive coil, and store the data. The sub-scalp electrode arrays were made using medical grade silicone and platinum. The electrode arrays were tunneled in the subgaleal cleavage plane between the periosteum and the overlying dermis. These were implanted for 3–7 months before euthanasia and histopathological assessment. EEG and impedance were recorded throughout the study. Main results. Impedance measurements remained low throughout the study for 11 of 12 channels over the recording period ranged from 3 to 5 months. There was also a steady amplitude of slow-wave EEG and chewing artifact (noise). The post-mortem CT and histopathology showed the electrodes remained in the subgaleal plane in 6 of 7 sheep. There was minimal inflammation with a thin fibrotic capsule that ranged from 4 to 101 μm. There was a variable fibrosis in the subgaleal plane extending from 210 to 3617 μm (S3–S7) due to surgical cleavage. One sheep had an inflammatory reaction due to electrode extrusion. The passive electrode array extraction force was around 1 N. Significance. Results show sub-scalp electrode placement was safe and stable for long term implantation. This is advantageous for diagnosis and management of neurological conditions where long-term, EEG monitoring is required.
Design and kinematic of a dexterous bioinspired elephant trunk robot with variable diameter
Authors: Zhou Pan , Yao Jiantao , Wei Chunjie , Zhang Shuai , Zhang Hongyu , Qi Shupeng 
Published: May 2022

Abstract
How to further improve the dexterity of continuum robots so that they can quickly change their structural size like flexible biological organs is a key challenge in the field of robotics. To tackle this dexterity challenge, this paper proposes a soft-rigid coupled bioinspired elephant trunk robot with variable diameter, which is enabled by combining a soft motion mechanism with a novel rigid variable-diameter mechanism (double pyramid deployable mechanism). The integration of these two mechanisms has produced three significant beneficial effects: (i) The coexistence of multi-degree-of-freedom motion capability and variable size function greatly improves the dexterity of the elephant trunk robot. (ii) The motion refinement can be improved by structural amplification, making up for the low resolution of soft actuators. (iii) Its stiffness can be increased by enlarging its diameter, while its reachable workspace can be increased by decreasing its diameter. Thus, the elephant trunk robot can optimize its performance when facing different tasks by opening and closing the rigid variable-diameter mechanism. Further, we established a kinematic model of the elephant trunk robot by the structure discretization method and the principle of mechanism equivalence, and experimentally verified its reasonableness. The demonstration experiments show that the elephant trunk robot has good flexibility. This work provides a new variable diameter configuration for continuum robots, and presents a method of how to analyze the kinematics of continuum mechanisms using rigid mechanism theory.
Bioinspired morphing wings: mechanical design and wind tunnel experiments
Authors: Kilian Lukas , Shahid Farzeen , Zhao Jing-Shan , Nayeri Christian Navid 
Published: May 2022

Abstract
Bioinspired morphing wings are part of a novel research direction offering greatly increased adaptability for use in unmanned aerial vehicles. Recent models published in the literature often rely on simplifications of the bird wing apparatus and fail to preserve many of the macroscopic morphological features. Therefore, a more holistic design approach could uncover further benefits of truly bioinspired bird wing models. With this issue in mind, a prototype inspired by crow wings (Corvus genus) is developed, which is capable of planform wing morphing. The prototype imitates the feather structure of real birds and replicates the folding motion with a carbon fiber reinforced polymer skeleton with one controllable degree of freedom. The mechanism supplies a smooth airfoil lifting surface through a continuous morphing motion between a fully extended and a folded state. When extended, it has an elliptic planform and emarginated slots between primary remiges. In the folded state, the wingspan is reduced by 50% with a 40% reduction in surface area and the aspect ratio decreases from 2.9 to 1.2. Experimental data from a subsonic wind tunnel investigation is presented for flow velocities ranging from 5 to 20 m s−1, corresponding to Reynolds numbers between 0.7 × 105–2.8 × 105. The wing is analyzed in the three static states (folded, intermediate, and extended) through aerodynamic coefficients and flow visualizations along the surface. The bioinspired design enables the wing to capture several phenomena found on real bird wings. Through its morphing capabilities and intrinsic softness, the wing can sustain large angles of attack with greatly delayed stall and maintain optimal performance at different velocities.
Rapid fabrication of tendon-like collagen gel via simultaneous fibre alignment and intermolecular cross-linking under mechanical loading
Authors: Maeda Eijiro , Kawamura Ryota , Suzuki Takashi , Matsumoto Takeo 
Published: May 2022

Abstract
Artificial tissue replacement is a promising strategy for better healing outcomes for tendon and ligament injuries, due to the very limited self-regeneration capacity of these tissues in mammals, including humans. Because clinically available synthetic and biological scaffolds for tendon repair have performed more poorly than autografts, both biological and mechanical compatibility need to be improved. Here we propose a rapid fabrication method for tendon-like structure from collagen hydrogel, simultaneously achieving collagen fibre alignment and intermolecular cross-linking. Collagen gel, 24 h after polymerization, was subjected to mechanical loading in the presence of the chemical cross-linker, genipin, for 24 or 48 h. Mechanical loading during gel incubation oriented collagen fibres in the loading direction and made chemical cross-linking highly effective in a loading magnitude-dependent manner. Gel incubated with 4 g loading in the presence of genipin for 48 h possessed tensile strength of 4 MPa and tangent modulus of 60 MPa, respectively, which could fulfill the minimum biomechanical requirement for artificial tendon. Although mechanical properties of gels fabricated using the present method can be improved by using a larger amount of collagen in the starting material and through optimisation of mechanical loading and cross-linking, the method is a simple and effective for producing highly aligned collagen fibrils with excellent mechanical properties.
Temporal variations of the association between summer season heat exposure and hospitalizations for renal diseases in Queensland, Australia, 1995–2016
Authors: Lu Peng , Miao Jiaming , Feng Shurong , Green Donna , Lim Youn-Hee , Gao Xiuwei , Li Shanshan , Guo Yuming 
Published: May 2022

AbstractTo examine the temporal trends of the association between heat exposure and hospitalizations for renal disease in Queensland, Australia, between the summer season of 1 December 1995 and 31 December 2016. A total of 238 427 de-identified hospitalization records for renal disease were collected from Queensland Health. Meteorological data was obtained from the Scientific Information for Land Owners. Summer season means four consecutive months with higher daily mean temperatures. We conducted a time-stratified case-crossover study using conditional quasi-Poisson regression model and applied a time-varying distributed lag non-linear model were used to evaluate the temporal trends of the associations between 1 °C increase in daily mean temperatures (over 0–10 lags) and hospitalizations for renal diseases. We also conducted stratified analyses by sex, age, climate zone, socioeconomic status, and cause-specific renal diseases. Overall, the associations between high temperature and hospitalizations for renal diseases showed a decreasing trend during the summer seasons from 1995 to 2016. However, the heat-related effects in males increased from 3.0% (95% CI: 2.2%, 3.9%) in 1995 to 4.8% (95% CI: 3.9%, 5.6%) in 2016. In the elderly cohort (both sexes), there was a similar increase over time 2.0% (95% CI: 1.0%, 3.0%) in 1995 to 6.3% (95% CI: 5.4%, 7.3%) in 2016. People living in hotter climate zones and those living in relatively socioeconomically disadvantaged areas also showed an increasing trend. In the cause-specific disease analysis, the increasing trend was found in renal failure, with heat-related effects increased from 3.45% (95% CI: 2.31%, 4.60%) in 1995 to 8.19% (95% CI: 7.03%, 9.36%) in 2016. Although the association between temperature and hospitalizations for renal diseases showed a decreasing trend in Queensland’s hot season between 1995 and 2016, the susceptibility to high temperatures is increasing in males, the elderly of both sexes, those living in hotter climate areas, and socioeconomically disadvantaged areas. This increasing trend of susceptibility is a great concern and indicates a strong need for targeted public health promotion campaigns.
Electric double layers with modulated surface charge density: exact 2D results
Authors: Šamaj Ladislav 
Published: May 2022

Abstract
Electric double layers (EDL) with counterions only, say electrons with the elementary charge −e, in thermal equilibrium at the inverse temperature β are considered. In particular, we study the effect of the surface charge modulation on the particle number density profile and the pressure. The mobile particles are constrained to the surface of a 2D cylinder and immersed in vacuum (no dielectric image charges). An EDL corresponds to the end-circle of the cylinder which carries a (fixed) position-dependent line charge density. The geometries of one single EDL and two EDLs at distance d are considered; the particle density profile is studied for both geometries, the effective interaction of two EDLs is given by the particle pressure on either of the line walls. For any coupling constant Γ ≡ βe
2 = 2 × integer, there exists a mapping of the 2D one-component Coulomb system onto the 1D interacting anticommuting-field theory defined on a chain of sites. Using specific transformation symmetries of anticommuting variables, the contact value theorem is generalized to the EDL with modulated line charge density. For the free-fermion coupling Γ = 2 it is shown that, under certain conditions, the matrix of interaction strengths between anticommuting variables diagonalizes itself which permits one to obtain exact formulas for the particle density profile as well as the pressure. The obtained results confirm the previous indications of weak-coupling and Monte Carlo observations that the surface charge inhomogeneity implies an enhancement of the counterion density at the contact with the charged line and a diminution of the pressure between two parallel lines in comparison with the uniformly charged ones (with the same mean charge densities).
Assessment of the main rheological parameters of rocks during field development
Authors: Khabibullin M Ya 
Published: May 2022

Abstract
The total rock pressure on a formation wing is greater than the lateral pressure, and on the fold, on the contrary, the lateral rock pressure is greater than the total pressure. As a result, the formation material flows from wing zones to the fold, as a result of which the formation thickness on the fold increases, as noted by the studies of Soviet scientists. The study of the mechanism of hydraulic fracturing during water injection revealed large fracturing pressures in wells located in reduced parts of the structure (fold wings), and smaller pressures – in elevated parts (fold). The study showed that if the rock of the well bore zone is destabilized during field development for well operation, fresh water causes hydration and swelling or dispersion of clays, which act as the rock cementing material. This can both lead to a decrease in permeability and to the destruction of the well bore zone. This effect during well development may be prevented by using mineralized reservoir water or fresh water with hydration inhibitor additives such as NaCl (5-10%), CaCl2 (1-3%), KC1 (1-3%). Another complication in well completion is the colmatation of the well bore zone. In order to ensure the stability of the fixed part of the formation behind tubing in the bottomhole zone, there is a need to ensure the static equilibrium in the porous medium. Rocks with low rheological properties (low relaxation rate) provide longer resistance of the well bore zone to destruction.