bluuebunny/crossref_metadata_2025_split huggingface dataset:
The establishment of national diagnostic reference levels for adult SPECT-CT in Saudi Arabia
Authors: Al-Qahtani Saeed Mueed , Alidasroos Moaaz Aqeel , Alkhybari Essam M , Althomali Marwan Ahmed , Alomari Ali Hamed , Bawazeer Omemh Abdullah , Hawsawi Hassan B , Aamry Ali Ibrahim , Asiri Jaber Abdulwahab , Aloufi Azzam Abdulaziz , Aljehani Amr Dakhilallah , Al-Osaimi Maram Bandar , Alosaimi Areej Khalid , Alsulami Anwar Khalaf , Sabi Ahmed Yahya , Kamli Talal Mosa , Sulieman Abdelmoneim Adam , Ajlouni Abdul-Wali 
Published: July 2023

Abstract
This study aims to introduce national diagnostic reference levels (NDRLs) for adult hybrid single photon emission computed tomography (SPECT-CT) in nuclear medicine (NM) departments in the Kingdom of Saudi Arabia. The administered activity (AA) of radiopharmaceuticals, volume-weighted computed tomography dose index (CTDIvol) and dose length product (DLP) for ten hybrid SPECT/CT examinations were collected and analysed for one year. The median of AA, CTDIvol and DLP for each dose quantity was derived and the suggested national DRLs were determined based on the 75th percentile for all identified SPECT-CT examinations. A comparison of the defined adult NDRLs in Saudi Arabia with the published data of other countries was performed. Although there are no significant variations of the proposed NDRL of AA between countries, the proposed NDRLs of the integrated CT metrics exceed the published data in most procedures. NM departments are urged to consider optimisation for both image quality and radiation protection.
Teaching physics using Microsoft Excel-II
Authors: Uddin Zaheer , Razzak Atteeq , Ahmed Fayzan , Iqbal Majid 
Published: July 2023

Abstract
Conventional teaching is rapidly changing, and online and simulated software are adding up in teaching. Simulations on spreadsheets have become popular due to their ubiquitous and easily understandable. In this paper, we demonstrate three physics topics: the motion of a charged particle in a uniform magnetic field, the motion of a projectile, and the simple harmonic motion of a simple pendulum. The third example is a demonstration of an experiment on a simple pendulum to find the time period of a simple pendulum and study the amplitude’s effect on it. Students can perform the whole experiment on the spreadsheet in real-time.
An electromechanical dynamic stiffness matrix of piezoelectric stacks for systematic design of micro/nano motion actuators
Authors: Ling Mingxiang , Wu Shilei , Luo Zhihong , Chen Liguo , Huang Tao 
Published: July 2023

Abstract
Piezoelectric stacks have proved to be effective for micro/nano motion actuators with large blocking forces. A critical problem is to build their electro-mechanical model for systematic design of statics and dynamics including piezoelectric hysteresis and elasto-kinematics of compliant mechanisms. To ease this issue, this paper proposes a new electro-mechanical dynamic stiffness matrix of piezoelectric stacks to enable a systematic analysis. Positive and inverse piezoelectric effects are included into the dynamic stiffness matrix of Timoshenko beams in the form of Taylor’s series with a clear definition of physical parameters. Consequently, the Jacobian matrix, input/output stiffness, natural frequencies, frequency-domain spectrums of mechanical displacement and electrical impedance as well as the time-domain response of piezoelectric hysteresis can be fully obtained with a single modeling process. Particularly, the time-domain response in the presence of piezoelectric rate-dependent hysteresis and dynamic resonance behaviors of compliant mechanisms is captured in a parameter-insightful way but not the manner in Hammerstein hysteresis model with a black-box transfer function. Experiments on a proof-of-concept prototype of precision positioning stage verify the easy operation and satisfying prediction accuracy of the presented approach.
Quantum algorithm for twin extreme learning machine
Authors: Ning Tong , Yang Youlong , Du Zhenye 
Published: July 2023

Abstract
Twin extreme learning machine (TELM) is a powerful learning algorithm, which aims at learning two nonparallel hyperplanes for data classification. However, classical TELM algorithm becomes computationally expensive when it involves big data sets. In this paper, we devise a quantum TELM algorithm to address this issue. Specifically, we first utilize the quantum amplitude estimation algorithm to prepare the desired input states and then call the quantum linear systems of equations, which adopts block-encoding technique, to obtain the model parameters in the training process. Then we invoke the swap test to estimate the distances from a new data point to the two hyperplanes and then make a classification in the prediction stage. The final complexity analysis demonstrates that our algorithm has an exponential speedup under certain conditions over the classical counterpart.
Approximate Mei symmetries of pp-wave spacetimes
Authors: Kausar Umara , Feroze Tooba 
Published: July 2023

Abstract
In this paper, first order approximate Mei symmetries of the geodetic Lagrangian for some classes of the pp-wave spacetimes are obtained. These classes of pp-wave spacetimes include plane wave spacetimes in which (i). H = α
2
x
2(ii). H = α
x
2
u
−2 (iii). H = α
2
x
2
u
−4 and for pp-wave spacetimes (iv). H = α
x

n
(where H is called scale factor and α is a constant). After that, approximate Mei invariants are calculated corresponding to each case.
Study on neural entrainment to continuous speech using dynamic source connectivity analysis
Authors: Yang Kai , Wu Shuang , Zhou Di , Gan Lin , Zhang Gaoyan 
Published: July 2023

AbstractObjective.Many recent studies investigating the processing of continuous natural speech have employed electroencephalography (EEG) due to its high temporal resolution. However, most of these studies explored the response mechanism limited to the electrode space. In this study, we intend to explore the underlying neural processing in the source space, particularly the dynamic functional interactions among different regions during neural entrainment to speech.Approach.We collected 128-channel EEG data while 22 participants listened to story speech and time-reversed speech using a naturalistic paradigm. We compared three different strategies to determine the best method to estimate the neural tracking responses from the sensor space to the brain source space. After that, we used dynamic graph theory to investigate the source connectivity dynamics among regions that were involved in speech tracking.Main result.By comparing the correlations between the predicted neural response and the original common neural response under the two experimental conditions, we found that estimating the common neural response of participants in the electrode space followed by source localization of neural responses achieved the best performance. Analysis of the distribution of brain sources entrained to story speech envelopes showed that not only auditory regions but also frontoparietal cognitive regions were recruited, indicating a hierarchical processing mechanism of speech. Further analysis of inter-region interactions based on dynamic graph theory found that neural entrainment to speech operates across multiple brain regions along the hierarchical structure, among which the bilateral insula, temporal lobe, and inferior frontal gyrus are key brain regions that control information transmission. All of these information flows result in dynamic fluctuations in functional connection strength and network topology over time, reflecting both bottom-up and top-down processing while orchestrating computations toward understanding.Significance.Our findings have important implications for understanding the neural mechanisms of the brain during processing natural speech stimuli.
Hyperbolic function based hybrid consistent adaptive sequential DL algorithms for PIR sensor based intruder detection
Authors: De Pubali , Chatterjee Amitava , Rakshit Anjan 
Published: July 2023

Abstract
This study demonstrates that a novel dictionary learning
(DL) algorithm-based approach can be successfully used in
conjunction with an indigenously developed hardware module, using
four pyroelectric infrared (PIR) sensors, to enhance the performance
of an intruder detection system. In this work, initially, a
hyperbolic function based Consistent Adaptive Sequential Dictionary
Learning (CAS-DL) algorithm has been proposed (HCAS-DL). Then
another dictionary learning algorithm, called label consistency
based K-SVD (LCK-SVD) is considered, where the label information of
each dictionary atom has been introduced to enforce discriminability
in sparse code. The objective function in LCK-SVD is formuated
simultaneously considering the concept of label consistency (LC)
constraints, reconstruction errors, and classification errors. Next,
the newly proposed HCAS-DL is hybridized with LCK-SVD to form a
novel version of hybrid consistent adaptive sequential dictionary
learning approach, named here as the LC-HCAS-DL algorithm.
Extensive experiments have been performed to establish the
suitability of our proposed approach for the problem under
consideration. The performance evaluation clearly establishes that
the LC-HCAS-DL algorithm can achieve superior performance compared
to recently proposed LC-MCAS-DL algorithm and other state-of-the-art
algorithms for the intruder detection problem under consideration.
PicoTDC: a flexible 64 channel TDC with picosecond resolution
Authors: Altruda Samuele , Christiansen Jorgen , Horstmann Moritz , Perktold Lukas , Porret David , Prinzie Jeffrey 
Published: July 2023

Abstract
The PicoTDC is a 64 channel TDC (Time to Digital Converter) ASIC, with 3ps or 12ps time binning, developed at CERN for use in a large variety of high channel count scientific instrumentation. Acquired time measurements are processed on-chip with a programmable buffering and triggered data flow architecture before being read out on 1 to 4 byte-wise readout ports with a total readout bandwidth of up to 10 Gbps. Leading edge, falling edge or leading edge together with pulse width can be captured at burst rates as high as 1.2 GHz and sustained rate of 320 MHz per channel. Effective single-shot time resolution has been measured to be 3.7 ps RMS across all 64 channels over its full dynamic range and as good as 1.35 ps RMS when using an on-chip adjustment feature optimized for a specific channel (0.43 ps if averaged over multiple measurements). The PicoTDC is implemented in a 65 nm CMOS process and 20 k chips have been produced and packaged in a 400 pin plastic BGA package.
Effect of ultrasonic surface shot peening on the microstructure and properties of Cu-8Cr alloy
Authors: Wang Xiang , Jiang Chang , Liu Tao , Qin Dan , Chen Baoquan , Zhang Xuehui , Liang Tongxiang 
Published: July 2023

Abstract
Surface nanocrystalline layers were prepared on Cu-8Cr alloy using ultrasonic shot peening (USSP) technique by controlling the pellet size and shot peening time. The tissue morphology, microstructure, surface hardness, surface strength and corrosion resistance of the generated surface nanolayers were systematically characterized using x-ray diffractometer (XRD), scanning electron microscope (SEM), and the corresponding test methods. The results showed that the USSP treatment did not change the surface phase of Cu-8Cr alloy, but only refined the surface grains into nanocrystals. The pellet size and shot peening time had a large effect on the surface properties of Cu-8Cr alloy. The best overall surface properties were obtained with a shot size of 2 mm and a shot time of 30 min The average grain size of the nano-layer is about 66 nm, the surface hardness is increased to 126.69 HV0.05, the tensile strength reached 417 MPa, and the corrosion resistance of the alloy is significantly enhanced. The USSP treatment provides a new method for the preparation of CuCr alloys with excellent surface properties.
Second-harmonic generation in fluctuating Ising superconductors
Authors: Sonowal K , Parafilo A V , Boev M V , Kovalev V M , Savenko I G 
Published: July 2023

Abstract
In a two-dimensional noncentrosymmetric transition metal dichalcogenide Ising superconductor in the fluctuating regime under the action of a uniform external electromagnetic field, a second-harmonic generation (SHG) effect takes place. There emerge two contributions to this effect, one conventional, which is due to the electron gas in its normal state, and the other one is of the Aslamazov–Larkin nature. Namely, it originates from the presence of fluctuating Cooper pairs in the system when the temperature approaches the temperature of the superconducting transition in the sample from above. Employing a usual approach to Ising superconductors, we lift the valley degeneracy by application of a weak out-of-plane external magnetic field, which produces a Zeeman effect. In calculations, we use the Boltzmann equations approach for the electron gas in the normal state, and the time-dependent Ginzburg–Landau equations for the fluctuating Cooper pairs, and show the emergence of SHG electric current characterized by a temperature-dependent broadening and a redshift.
Plasma wave resonances in Graphene channels under controlled gate for high frequency applications
Authors: Mahi AbdelHamid , Mahi Fatima Zohra , Varani Luca 
Published: July 2023

Abstract
Several devices based on 2D materials have become interesting for high-frequency applications especially sensors, amplifiers and modulators of Terahertz frequencies. Moreover, High Electron Mobility Transistors (HEMTs) have emerged as important competitors owing to the high quality of resonances associated with plasma-wave oscillations in the channel. In this study, the plasma wave resonances in a Graphene channel of High Electron Mobility Transistors (HEMTs) were studied. The calculations were based on our small-signal model and therefore can determine the resonances and voltage gain of the Monolayer and Bilayer graphene channels. The influence of the dielectric substrates between the gate and the channel, impurity depth positions and channel materials (InGaAs, Bilayer and Monolayer graphene) on the dynamic behavior of the Graphene transistor was investigated. This analysis can extract the high performance conditions of HEMTs Graphene amplifiers.
The effect of ultrasonic field on the microstructure and corrosion behavior of Fe-based amorphous coating applied to selective laser melting
Authors: Taheri Morteza , Razavi Mansour 
Published: July 2023

Abstract
This study was conducted to investigate the effect of the ultrasonic field on the preparation of amorphous/crystalline Fe-based coatings. For this purpose, Fe86.3Si 5.9B3.2Cr4.6 (wt%) powder was deposited on GTD-111 superalloy substrate with and without ultrasonic field by selective laser melting method. After coating, the corrosion behavior, microstructure, and hardness of the amorphous coating were investigated. The results showed that in conditions without ultrasonic vibration, the growth of grains starts in columnar form. At the same time, the use of an ultrasonic field inhibits columnar growth and creates equiaxed grains. In addition, the ultrasonic field increased the amorphous phase by 34.5%. This is attributed to the increased solidification rate caused by the cavitation effect. The experimental results of corrosion show that the self-corrosion current density of 6.83×10−7 A⋅cm2 is obtained due to the refinement of the microstructure and the increase of the amorphous phase. The wear results showed that the increase in the amorphous phase, as well as the decrease in the grain size, reduction in the grain ratio, and the increase in the tendency to equiaxed grains when using the ultrasonic field, reduce the coefficient of friction by 97%.
Urinary bladder phantom mimicking mechanical properties and pressure during filling
Authors: Verstraeten Maxime , Bou Kheir George , Vande Perre Louis , Raffoul Romain , Chavez Cerda Javier , Delchambre Alain , Roumeguere Thierry , Vanhoestenberghe Anne , Nonclercq Antoine 
Published: July 2023

Abstract

Objective. Phantoms that mimic healthy or diseased organ properties can complement animal models for surgical planning, training, and medical device development. If urodynamic studies rely on pressure-volume curves to assess lower urinary tract symptoms, there is an unsatisfied need for a bladder phantom that accurately mimics the bladder stretching capabilities and compliant behaviour during physiological filling. Approach. We demonstrate the suitability of water-soluble 3D-printed moulds as a versatile method to fabricate accurate phantoms with anatomical structures reconstructed from medical images. We report a phantom fabricated with silicone rubber. A wire net limits the silicone expansion to model the cystometric capacity. A mathematical model describes the pressure increase due to passive hyperelastic properties. Main results. The phantom reproduces the bladder’s mechanical properties during filling. The pressure-volume curve measured on the phantom is typical of cystometric studies, with a compliance of 25.2 ± 1

ml

cmH

2

O

−
1

.

The root-mean-square error between the theoretical model and experimental data is 2.7

cmH

2

O
.

The compliance, bladder wall thickness, cystometric capacity and pressure near the cystometric capacity of the phantom can be tuned to mimic various pathologies or human variability. Significance. The manufacturing method is suitable for fabricating bladder and other soft and hollow organ phantoms. The mathematical model provides a method to determine design parameters to model healthy or diseased bladders. Soft hollow organ phantoms can be used to complement animal experimentations for developing and validating medical devices aiming to be anchored on these organs or monitor their activity through pressure and strain measurement.
Numerical study of the self-pulsing of DC discharge: from corona to parallel-plate configurations
Authors: ZHANG Manqi , HE Feng , CAI Hongmei , ZHANG Zeduan , GAO Zhiliang , YANG Ming , WANG Ruojue , ZHANG Yu , LI Ben , WANG Lei , OUYANG Jiting 
Published: July 2023

Abstract
We present here an investigation of the self-pulsing phenomenon of negative corona and parallel-plate discharge in argon within one frame of a one-dimensional fluid model in cylinder–cylinder electrode geometry. The transition from corona to parallel-plate discharge is obtained by changing the inner and outer radii of the electrodes. The model reproduces the self-pulsing waveform well and provides the spatiotemporal behaviors of the charged particles and electric field during the pulse. The self-pulsing shows a common feature that occurs in various configurations and that does not depend on a specific electrode structure. The self-pulsing is the transformation between a weak-current Townsend mode and a large-current normal glow mode. The behavior of the positive ions is the dominant factor in the formation of the pulse.
Multiobjective variational quantum optimization for constrained problems: an application to cash handling
Authors: Díez-Valle Pablo , Luis-Hita Jorge , Hernández-Santana Senaida , Martínez-García Fernando , Díaz-Fernández Álvaro , Andrés Eva , José García-Ripoll Juan , Sánchez-Martínez Escolástico , Porras Diego 
Published: July 2023

Abstract
Combinatorial optimization problems are ubiquitous in industry. In addition to finding a solution with minimum cost, problems of high relevance involve a number of constraints that the solution must satisfy. Variational quantum algorithms (VQAs) have emerged as promising candidates for solving these problems in the noisy intermediate-scale quantum stage. However, the constraints are often complex enough to make their efficient mapping to quantum hardware difficult or even infeasible. An alternative standard approach is to transform the optimization problem to include these constraints as penalty terms, but this method involves additional hyperparameters and does not ensure that the constraints are satisfied due to the existence of local minima. In this paper, we introduce a new method for solving combinatorial optimization problems with challenging constraints using VQAs. We propose the multi-objective variational constrained optimizer (MOVCO) to classically update the variational parameters by a multiobjective optimization performed by a genetic algorithm. This optimization allows the algorithm to progressively sample only states within the in-constraints space, while optimizing the energy of these states. We test our proposal on a real-world problem with great relevance in finance: the cash handling problem. We introduce a novel mathematical formulation for this problem, and compare the performance of MOVCO versus a penalty based optimization. Our empirical results show a significant improvement in terms of the cost of the achieved solutions, but especially in the avoidance of local minima that do not satisfy any of the mandatory constraints.
The influence of variable-heavy chain families on IgG2, 3, 4, FcγRs and B-cell superantigens protein G and L binding using biolayer interferometry
Authors: Deacy Anthony M , Gan Samuel Ken-En 
Published: July 2023

Abstract
As the most abundant immunoglobulin in blood and the most common human isotype used for therapeutic monoclonal antibodies, the engagement and activation of its Fc receptors by IgGs are crucial for antibody function. Assumed to be relatively constant within subtypes, recent studies reveal that antibody variable regions exert distal effects of modulating antibody–receptor interactions on antibody isotypes. These variable (V)-region distal effects are also expected for the IgG subtypes. With an in-depth understanding of the V-region effects, researchers can make a more informed antibody engineering approach and antibody purification strategy accounting for the functions of microbial immune evasion . In this study, we created a panel of IgG2/IgG3/IgG4 antibodies by changing the VH family (VH1–7) frameworks while retaining the complementary determining regions of pertumuzab and measured their interactions with FcγRIa, FcγRIIaH167, FcγRIIaR167, FcγRIIb/c, FcγRIIIaF176, FcγRIIIaV176, FcγRIIIbNA1 and FcγRIIIbNA2 receptors alongside B-cell superantigens Protein L and G using biolayer interferometry. The panel of 21 IgGs demonstrated that the VH frameworks influenced receptor binding sites on the constant region in a non-canonical manner. However, there was minimal influence on the binding of bacterial B-cell superantigens Proteins L and Protein G on the IgGs, showing their robustness against V-region effects. These results demonstrate the role of V-regions during the humanization of therapeutic antibodies that can influence FcR-dependent immune responses while retaining binding by bacterial B-cell superantigens for antibody purification. These in vitro measurements provide a clue to detailed antibody engineering and understanding of antibody superantigen functions that would be relevant with in vivo validation.