bluuebunny/crossref_metadata_2025 huggingface dataset:
A smooth control allocation method for a distributed electric propulsion VTOL aircraft test platform
Authors: Qin Zijie , Liu Kun , Zhao Xi
Published: January 2023

Distributed electronic propulsion (DEP) aircraft with vertical take‐off and landing (VTOL) ability mostly equipped with multiple redundant tiltable propulsors, which are used to provide not only thrusts, but also control torque in all flight mode. The features make the control allocation problem of these aircraft both complex and important. Therefore, this paper proposes: (і) a prototype platform for DEP VTOL aircraft that allows researchers to design and analyse control allocation strategies, and (іі) a uniform hierarchical control allocation method that can be adapted to both MC and FW modes. The platform contains ten fully actuated thrusters, which are distributed in the scaled geometry of a typical DEP‐VTOL aircraft. The proposed control allocation strategy uses hierarchical structure to avoid high‐dimensional matrix operations for the redundant actuators. The additional constraints on the thrust and tilt angles of the actuators are addressed by adopting cascade generalized inversion (CGI) to force decompensation (FD)‐based methods by a coordinate transformation. A novel smooth strategy through Schur Complement is also presented to achieve steady and smooth transition from MC to FW mode. Finally, the proposed method is implemented in the authors’ novel platform in both simulations and flight experiments to demonstrate its effectiveness and smoothness.
The triple-peaked afterglow of GRB 210731A from X-ray to radio frequencies
Authors: de Wet S. , Laskar T. , Groot P. J. , Cavallaro F. , Nicuesa Guelbenzu A. , Chastain S. , Izzo L. , Levan A. , Malesani D. B. , Monageng I. M. , van der Horst A. J. , Zheng W. , Bloemen S. , Filippenko A. V. , Kann D. A. , Klose S. , Pieterse D. L. A. , Rau A. , Vreeswijk P. M. , Woudt P. , Zhu Z.-P.
Published: January 2023

Context.GRB 210731A was a long-duration (T90 = 22.5 s) gamma-ray burst discovered by the Burst Alert Telescope (BAT) aboard theNeil Gehrels SwiftObservatory.Swifttriggered the wide-field, robotic MeerLICHT optical telescope in Sutherland; it began observing the BAT error circle 286 s after theSwifttrigger and discovered the optical afterglow of GRB 210731A in its first 60-sq-band exposure. Multi-colour observations of the afterglow with MeerLICHT revealed a light curve that showed three peaks of similar brightness within the first four hours. The unusual optical evolution prompted multi-wavelength follow-up observations that spanned from X-ray to radio frequencies.

Aims.We present the results of our follow-up campaign and interpret our observations in the framework of the synchrotron forward shock model.

Methods.We performed temporal and spectral fits to determine the spectral regime and external medium density profile, and performed detailed multi-wavelength theoretical modelling of the afterglow following the last optical peak at ∼0.2 days to determine the intrinsic blast wave parameters.

Results.We find a preference for a stellar wind density profile consistent with a massive star origin, while our theoretical modelling results in fairly typical shock microphysics parameters. Based on the energy released inγrays and the kinetic energy in the blast wave, we determine a low radiative efficiency ofη ≈ 0.02. The first peak in the optical light curve is likely the onset of the afterglow. We find that energy injection into the forward shock offers the simplest explanation for the subsequent light curve evolution, and that the blast wave kinetic energy increasing by a factor of ∼1000 from the first peak to the last peak is indicative of substantial energy injection. Our highest-likelihood theoretical model over-predicts the 1.4 GHz flux by a factor of approximately three with respect to our upper limits, possibly implying a population of thermal electrons within the shocked region.
Discovery of periodicities in two highly variable intermediate polars towards the Galactic centre
Authors: Mondal Samaresh , Ponti Gabriele , Haberl Frank , Mori Kaya , Rea Nanda , Morris Mark R. , Campana Sergio , Anastasopoulou Konstantina
Published: January 2023

Aims. We performed a systematic analysis of X-ray point sources within 1.°5 of the Galactic centre using archival XMM-Newton data. While doing so, we discovered Fe Kα complex emission and pulsation in two highly variable sources, 4XMM J174917.7–283329 and 4XMM J174954.6–294336. In this work we report the findings of the X-ray spectral and timing studies.

Methods. We performed detailed spectral modelling of the sources and searched for pulsation in the light curves using Fourier timing analysis. We also searched for multi-wavelength counterparts for the characterization of the sources.

Results. The X-ray spectrum of 4XMM J174917.7–283329 shows the presence of complex Fe K emission in the 6–7 keV band. The equivalent widths of the 6.4 and 6.7 keV lines are 99−72+84 and 220−140+160 eV, respectively. The continuum is fitted by a partially absorbed apec model with a plasma temperature of kT = 13−2+10 keV. The inferred mass of the white dwarf (WD) is 0.9−0.2+0.3 M⊙. We detected pulsations with a period of 1212 ± 3 s and a pulsed fraction of 26 ± 6%. The light curves of 4XMM J174954.6–294336 display an asymmetric eclipse and dipping behaviour. To date, this is only the second known intermediate polar to show a total eclipse in X-rays. The spectrum of the sources is characterized by a power-law model with photon index Γ = 0.4 ± 0.2. The equivalent widths of the iron fluorescent (6.4 keV) and Fe XXV (6.7 keV) lines are 171−79+99 and 136−81+89 eV, respectively. The continuum is described by emission from optically thin plasma with a temperature of kT ∼ 35 keV. The inferred mass of the WD is 1.1−0.3+0.2 M⊙. We detect coherent pulsations from the source with a period of 1002 ± 2 s. The pulsed fraction is 66 ± 15%.

Conclusions. The spectral modelling indicates the presence of intervening clouds with a high absorbing column density in front of both sources. The detected periodic modulations in the light curves are likely associated with the spin period of WDs in magnetic cataclysmic variables. The measured spin period, hard photon index, and equivalent width of the fluorescent Fe Kα line are consistent with the values found in intermediate polars. 4XMM J174954.6–294336 has already been classified as an intermediate polar, and we suggest that 4XMM J174917.7–283329 is a new intermediate polar. The X-ray eclipses in 4XMM J174954.6–294336 are most likely caused by a low-mass companion star obscuring the central X-ray source. The asymmetry in the eclipse is likely caused by a thick bulge that intercepts the line of sight during the ingress phase but not during the egress phase located behind the WD along the line of sight.
Thin layers of microwave absorbing metamaterials with carbon fibers and FeSi alloy ribbons to enhance the absorption properties
Authors: Huang Lingxi , Duan Yuping , Pang Huifang
Published: January 2023

In order to break through the bottleneck of narrow effective absorption bandwidth (reflection loss RL ≤ −10 dB) of microwave absorbing materials, herein, we fabricate the metamaterials with carbon fiber (CF) and FeSi alloy (FSA) ribbon metastructure which is distributed in the carbonyl iron powders (CIP)/polyurethane (PU) matrix. The experimental results show that the microwave absorption capacity of the matrix can be significantly enhanced by CF. Compared with the pure matrix, the effective absorption bandwidth increases from 9.4–13.44 GHz to 11–16.8 GHz when the CF is parallel to the electric field vector and the spacing between adjacent CF is 20 mm. Furthermore, the CF and FSA ribbons are arranged in the matrix as an orthogonal arrangement, and the best absorption bandwidth cover 9.76–14.46 GHz when the electric field is parallel and 9.96–14.1GHz when the electric field is vertical when the spacing is 30 mm. The electromagnetic simulation of the metamaterials is calculated, it is proved that the increase of effective absorption bandwidth is due to the strengthening of carbon fiber and its coupling with FSA ribbon. This paper provides a new research path for improving the absorption properties of thin layer microwave absorbing materials.
Identifying a Clinical Informatics or Electronic Health Record Expert Witness for Medical Professional Liability Cases
Authors: Sittig Dean F. , Wright Adam
Published: January 2023

Background The health care field is experiencing widespread electronic health record (EHR) adoption. New medical professional liability (i.e., malpractice) cases will likely involve the review of data extracted from EHRs as well as EHR workflows, audit logs, and even the potential role of the EHR in causing harm.

Objectives Reviewing printed versions of a patient's EHRs can be difficult due to differences in printed versus on-screen presentations, redundancies, and the way printouts are often grouped by document or information type rather than chronologically. Simply recreating an accurate timeline often requires experts with training and experience in designing, developing, using, and reviewing EHRs and audit logs. Additional expertise is required if questions arise about data's meaning, completeness, accuracy, and timeliness or ways that the EHR's user interface or automated clinical decision support tools may have contributed to alleged events. Such experts often come from the sociotechnical field of clinical informatics that studies the design, development, implementation, use, and evaluation of information and communications technology, specifically, EHRs. Identifying well-qualified EHR experts to aid a legal team is challenging.

Methods Based on literature review and experience reviewing cases, we identified seven criteria to help in this assessment.

Results The criteria are education in clinical informatics; clinical informatics knowledge; experience with EHR design, development, implementation, and use; communication skills; academic publications on clinical informatics; clinical informatics certification; and membership in informatics-related professional organizations.

Conclusion While none of these criteria are essential, understanding the breadth and depth of an individual's qualifications in each of these areas can help identify a high-quality, clinical informatics expert witness.
Comparison Between Thyroid Stimulating Immunoglobulin and
TSH-Receptor Antibodies in the Management of Graves’
Orbitopathy
Authors: Khamisi Selwan , Lundqvist Martin , Engström Britt Edén , Larsson Anders , Karlsson F Anders , Ljunggren Östen
Published: January 2023

Objectives TSH-receptor antibodies (TRAb) targeting the TSH receptor
(TSH-R) induce hyperthyroidism in Graves´ disease (GD). Graves´
orbitopathy (GO) is influenced by stimulation of the TSH-R in the orbita. GO has
been, among other factors, linked to high TRAb levels. Thyroid stimulating
immunoglobulins (TSI) is a relatively new method for assessing TSH-receptor
antibodies. The aim of this study was to investigate the role of TSI in the
management of GO.

Methods Patients with newly diagnosed GD (n=30, median age 55
years (range 35–72), 29 women) received pharmacological therapy
(methimazole+++thyroxine) for up to 24 months. GO was
identified by clinical signs and symptoms. Eleven patients had GO at diagnosis,
and another six developed GO during treatment. Blood samples for TSI and other
thyroidal biomarkers were obtained at baseline and on five occasions during the
24-month follow-up. Twenty-two subjects completed the drug regimen without
surgery or radioiodine treatment.

Results At baseline, TSI was highly correlated with TRAb
(r

s
=0.64, p<0.001), and both
assays similarly correlated to fT3 values. TSI and TRAb did not differ
significantly between GO and non-GO patients for visit v1 (n=30, 17 GO
during the whole study) or at follow-up (n=22, 12 GO during the whole
study). During follow-up, levels of TSI and TRAb decreased and normalized in
both groups.

Conclusion The present study does not support any added benefit of TSI
compared to TRAb for the prediction and management of GO.
Multilayer and Thin Transparent Conducting Oxide Fabrication Using RF Magnetron Sputtering on Flexible Substrates
Authors: Swami Sanjay Kumar , Barman Bidyut , Kumar Anuj , Dutta Viresh
Published: January 2023

In this work, the fabrication of multilayered transparent conductive oxides (TCOs), ZnO–Ag–ZnO (Z-TCO) and AZO–Ag–AZO (AZ-TCO), on flexible polyethylene terephthalate (PET) substrate using radio frequency (RF) magnetron sputtering is reported, with the optical and electrical properties comparable to those of the commercially available Sn-doped indium oxide (ITO) on the PET substrate. The growth of Z-TCO and AZ-TCO layers on PET (with surface roughness ~5 – 7 nm) shows similar surface characteristics to that on the glass substrate. The multilayered Z-TCO and AZ-TCO (total thickness ~70 nm) with 10 nm of Ag thickness (named Z-2 and AZ-2, respectively) exhibit a maximum transparency of 82.7% and 86.4%, at 515 and 498 nm, respectively. The AZ-2 layer has a lower electrical resistivity of 3.92 × 10−5 Ω cm with a lower sheet resistance of 5.6 Ω/sq, whereas for ITO on PET these values are 2.62 × 10−4 Ω cm and 14.5 Ω/sq, respectively. The AZ-2 layer also gives an excellent figure of merit (FoM) of 21.3 × 10−3 Ω−1, which is better than the FoM for ITO PET (17.3 × 10−3 Ω−1). Therefore, the flexible multilayer TCOs prepared using RF magnetron sputtering on PET substrates on a large area can have better optoelectronic properties than commercial flexible ITO coating and can be used in flexible optoelectronic devices.
The Scholarly Impact of Student Authorship in Ophthalmology
Authors: Prasad Minali , Paracha Munizay , Goodman Deniz , Cabral Howard J. , Christiansen Stephen P. , Subramanian Manju L.
Published: January 2023

Purpose The H-index (Hi), an author-level metric of scholarly impact, is predictive of future scientific achievement. We sought to analyze the scholarly impact of student authorship on the Hi of corresponding authors (CAs) within a major academic journal in the specialty of ophthalmology.

Materials and Methods We compared the Hi of all unique CAs for manuscripts published in Ophthalmology (Journal of the American Academy of Ophthalmology) in 2008, 2012, and 2016. Data abstraction was completed twice: in October 2018 and March 2021. We further grouped published articles for CAs into those with student authors (StA) and those without (nStA). Primary analysis involved a linear regression analysis with change in Hi from October 2018 to March 2021 as the outcome variable, CA groups as the predictor variable, adjusting for the covariates of baseline Hi, the year when the CA published his or her article, number of research items published in October 2018, and the academic appointment of the CAs. Secondary analysis involved a linear regression analysis with change in Hi from October 2018 to March 2021 as the outcome variable, total number of student authors per CA as the predictor variable, adjusting for the covariates of baseline Hi, the year CA published his or her article, number of research items published in October 2018, and the academic appointment of the CAs.

Results The number of student authors increased from 168 in 2008 to 192 in 2016. Of the 902 articles, 316 articles were co-authored by one or more student authors. The average change in Hi of CAs publishing with student authors (StA, 11.0 ± 14.7) was significantly greater (p < 0.0001) than the change in Hi of CAs publishing without student authors (nStA, 6.2 ± 6.2). As the total number of student authors increased, the change in Hi of CAs increased linearly for all years combined (regression coefficient = 1.70, p-value < 0.0001).

Conclusion CAs publishing with students in the field of ophthalmology have a higher scholarly impact than those publishing without students. The development of programs to integrate students into ophthalmology research early on may encourage their pursuit of a career in ophthalmology, while advancing the careers of their mentors.
An Implicit Cause of Prolonged Neonatal Jaundice: Vitamin B12 Deficiency
Authors: Aygun Erhan , Sayman Ozden Aksu , Erturk Emine Yurdakul , Yılmaz Semerci Seda , Kanburoglu Mehmet Kenan
Published: January 2023

Objective Prolonged jaundice is defined as a serum bilirubin level of more than 5 mg/dL, which persists at postnatal 14 days in term infants and 21 days following birth in preterm infants. Although the underlying causes cannot be found in the majority of prolonged jaundice cases, this may be the first sign of a serious issue. Therefore, this study aimed to evaluate the association between vitamin B12 deficiency and prolonged jaundice in newborns.

Material and Methods This descriptive cross-sectional study was performed in a university hospital between January 1, 2015 and October 1, 2020. All participants consisted of infants who were admitted to the pediatric outpatient clinics. Infants > 35 weeks of gestation and with prolonged jaundice of unknown etiology were included in the study group. The control group consisted of infants > 35 weeks of gestation without prolonged jaundice. Demographic and clinical characteristics and serum vitamin B12 levels were evaluated comparatively.

Results A total of 126 infants, 66 of whom had prolonged jaundice, were included. The mean gestational week of the study group was 38.4 ± 1.8, and the control group was 38.6 ± 1.9 weeks. There was no difference between the groups in terms of demographics and laboratory data. The vitamin B12 level of the study group was significantly lower (median = 170 pg/mL) than the control (median = 268 pg/mL).

Conclusion Based on the findings of this study, vitamin B12 deficiency was thought to be an important cause of prolonged jaundice, and further studies are needed to explain the role of vitamin B12 deficiency in the etiology of prolonged jaundice.
Structural, conductivity, and complex impedance properties of the La0.7Ag0.3Mn1−xZnxO3 (x = 0 and x = 0.025) samples
Authors: Toumi S. , Hassayoun O. , Mohamed Baazaoui , Farah Kh , Meznah M. Alanazi
Published: January 2023

In this paper, the structural and dielectric properties of La0.7Ag0.3Mn1−xZnxO3 (x = 0 and 0.025) manganite system are investigated. The x-ray diffraction analysis confirms that all compounds crystallized in the rhombohedral structure with R3̄C space group. The effects of Zn substitution on the crystal structure and the dielectric properties were studied by using the impedance spectroscopy technique at room temperature and over a wide range of frequencies. Electrical conductance curves are found to obey the Jonscher universal power law. We note a decrease in the conductivity when increasing the Zn content from x = 0 to x = 0.025. This behavior can be associated with the introduction of a very low concentration of a non-magnetic Zn ion, which distorts the octahedral MnO6 neighbor. The analysis of the complex impedance spectra reveals a single semicircular arc reflecting a non-Debye-type relaxation process. We conclude from the best fits that the equivalent circuit formed in our case is defined as a grain resistance Rg in series with a parallel combination of grain boundary resistance Rgb and constant phase element impedance (ZCPE).
Multiple seepage model and gas production simulation of shale with power law fracture distribution
Authors: Gu Jiayi , Liu Guannan , Gao Feng , Hu Yuhao , Ye Dayu
Published: January 2023

Changes in the internal microstructure of shale reservoirs have a significant effect on gas production. In this research, based on the double power law model and the triple medium theory, a triple medium model of shale multi-scale power law fracture distribution is constructed. The accuracy of the model is verified by comparing with the actual test results. Then, the model is used to analyze the relationship between shale stress, permeability, and three kinds of pore media as well as the influence of power law parameters and external force on reservoir microstructure and macroscopic gas production. The findings indicate that (1) the microstructure of shale reservoirs is affected by power law parameters and external forces; (2) gas exchange can cause the evolution of reservoir structure; and (3) the stress change of a single system will cause stress rearrangement of the whole system. This model provides a basic and comprehensive understanding for considering the various transport mechanisms of shale matrix and the microstructure change law of gas production process and proposes a new method for optimizing shale permeability simulation.
Anomalous Hall effect in Pt/Al-doped Cr2O3 epitaxial film
Authors: Iino Ion , Tada Tatsuo , Toyoki Kentaro , Nakatani Ryoichi , Shiratsuchi Yu
Published: January 2023

The anomalous Hall effect (AHE) was studied for the Pt(111)/(Al0.04Cr0.96)2O3(0001) epitaxial bilayer wherein the finite small magnetization is intentionally generated by doping Al in the pure antiferromagnetic Cr2O3. Despite that the (Al0.04Cr0.96)2O3 layer is an insulator, the sizable AHE accompanied with the hysteresis against the magnetic field reversal was obtained. The hysteresis is attributed to the magnetization reversal of the (Al0.04Cr0.96)2O3 layer. The anomalous Hall conductivity shows two characteristics in the temperature dependence: the turndown with decreasing temperature and the dip near the Néel temperature. These are distinct from the temperature dependence of the magnetization showing the monotonic decrease with increasing temperature. The discussion yields a plausible mechanism of the AHE as spin-chiral texture in the momentum space as the theory predicted for the Pt/Cr2O3 interface.
Quantum Hall effect systems of electrons with anisotropic patterns
Authors: Ciftja Orion
Published: January 2023

An almost ideal two-dimensional system of electrons can now be easily created in semiconductor heterojunctions. The quantum Hall effect state of the electrons is induced via the application of a strong perpendicular magnetic under specific quantum conditions. The most robust integer and/or fractional quantum Hall states already observed show the expected characteristic magnetoresistance for such systems. However, anisotropic patterns and features in transport properties have been seen for a few other peculiar cases. The origin of such anisotropic patterns may have various mechanisms or may also be due the specific details of the system and material such as the isotropic or anisotropic nature of the effective mass of electrons, the nature of the host substrate parameters, the nature of the interaction potentials, as well as other subtler effects. The interplay between all these factors can lead to many outcomes. In this work we consider small quantum Hall states of electrons at filling factor 1/6 and study the appearance of such anisotropic patterns as a result of some form of innate interaction anisotropy in the system.
Improvement in soft magnetic properties of thin bilayer ribbons using magnetoelastic effect
Authors: Yanai Takeshi , Yamaguchi Yuka , Hayashida Yuhi , Yamashita Akihiro , Nakano Masaki , Fukunaga Hirotoshi
Published: January 2023

We have prepared Fe-Ni-system bilayer ribbons with different magnetostriction (compositions) and investigated the improvement of soft magnetic properties using the magnetoelastic effect. A toroidal core with D = 10 mm was made from the Fe6Ni94/Fe56Ni44 bilayer ribbon, and the B-H loop of the core was measured. The shape of the hysteresis loop dramatically changed depending on the inner layer (inner magnetic phase). This result indicates that the direction of the anisotropy induced by bending stress was changed depending on the inner layer. The slope of the B-H loop and coercivity reduced when the Fe56Ni44 layer was on the inner side. From the experimental results, we found that domain rotation was dominant for the magnetization process. Consequently, the increase in the coercivity over frequency could be suppressed by controlling the magnetization process. From these results, we found that a thin bilayer ribbon with positive and negative magnetostriction constant is an attractive material for reducing iron losses under high frequency.
Do medical alliances truly work? Perspectives on health service utilisation among outpatients with chronic diseases in Shanghai, China
Authors: Sun Wanju , Zhu Haiyan , Zhang Linyi , Wang Zhaoxin , Luo Li , Qi Weigang , Qi Hualin , Hua Yingxue , Gao Xiang , Yuan Ling , Shi Jianwei
Published: January 2023

Background To achieve proper health utilisation among various health institutions and improve primary care capacity, China implemented medical alliance (MA) reform as part of healthcare reforms in 2009. With chronic disease management as the focus and priority of primary health institutions, this study aimed to analyse the specific distribution and trends of outpatient visits to various levels of health institutions (community health centres (CHCs) vs hospitals) in MAs. Methods All outpatient data were extracted from the Chuansha MA in Pudong New Area, Shanghai, between 2016 and 2020, and submitted to descriptive analysis, Chi-Square tests and correlation analysis. Results This article found that outpatients aged >60 years visited CHCs more than hospitals for some chronic diseases. The adjusted average costs of outpatients presented upward trends both in hospitals and in CHCs. Conclusions The Chuansha MA worked in guiding older outpatients to visit CHCs, but did not control the increasing medical costs. The Shanghai government should further improve medical capability of CHCs to attract all community-dwelling residents at all ages to implement hierarchical diagnosis and treatment systems, as well as make more efforts to control increasing medical costs.
Adjustment, mismatches and accommodation of procedural and conceptual meaning
Authors: Recio Fernández Inés , Loureda Óscar , Cruz Adriana
Published: January 2023

This contribution aims to set out the effects of discourse marking on processing. On the basis of examples from Spanish, we try to show the principles governing the interplay between the procedural meaning of discourse markers (connectives) and the conceptual meaning of the discourse segments linked by them. To determine these principles, two types of experiments were performed: one comparing marked and unmarked utterances, and a second one comparing utterances that activate mental representations that pragmatically match or clash with the instruction encoded by the connective. Evidence shows that (a) discourse marking by means of a connective generates a new route for accessing information; (b) procedural meaning is a definitory feature of connectives; (c) the procedural meaning of connectives introducesasymmetryandrigidityinto discourse as to conceptual meanings; (d) in mismatches between the assumption activated by the instructions of a connective and mind-stored assumptions, accommodation processes may take place, which are effortful but seek to guarantee the retrieval of cognitive effects from the utterance.
Investigation of the relationship of hearing aid users personality traits and hearing aid satisfaction
Authors: Kaymakçı Sude , Şerbetçioğlu Mustafa Bülent , Erol İrem Cavide
Published: January 2023

Objective:

Hearing aid satisfaction is in a relationship with the individual characteristics and personality traits of the user as well as the audiological variables. The aim of this study is to examine the effects of personality traits and individual characteristics on hearing aid satisfaction.

Methods:

The study involved 60 adults (29 females and 31 males) aged 18–65 years. The recruited participants were subjected to the Big Five Inventory (BFI) to determine personality traits and the Satisfaction with Amplification in Daily Living (SADL) to assess hearing aid satisfaction.

Results:

High levels of extraversion, agreeableness and conscientiousness were in positive relationship with hearing aid satisfaction, while high levels of neuroticism were negatively correlated with hearing aid satisfaction (p < .05). When gender results were compared, it was seen that female users reported a higher hearing aid satisfaction than men (p < .05).

Conclusion:

It is thought that during planning and carrying out the rehabilitation with hearing aids, considering individual characteristics such as personality, age, expectations, gender and experience, will contribute to hearing aid satisfaction.
Hellmann–Feynman theorem and internal pressure for atoms, molecules and plasmas under pressure
Authors: Mukherjee Neetik , Patra Chandra N , Roy Amlan K
Published: January 2023

Since the beginning of the twentieth century, confinement of atoms, molecules and plasma inside impenetrable sharp (hard) and smooth (soft) cavities has been studied with utmost interest. Physically, such situations introduce the trapping of a quantum system under high pressure. The internal pressure (

P

n
,
ℓ

) of the system under multi-megabar external pressure has not yet been explored. Also, there is a lack of Hellmann–Feynman theorem (HFT) in such a scenario, which is essential to derive a concrete analytical expression of

P

n
,
ℓ

under stressed condition. Here using a scaling concept we provide a general HFT in terms of expectation values of total energy, potential and kinetic energy of a given confined system. A change in boundary condition (from smooth to sharp and vice versa) does not affect this. Applying this proposed HFT, a closed-form expression of

P

n
,
ℓ

and

has been obtained for confined and shell-confined quantum systems. Based on this

P

n
,
ℓ

, several virial-like equations are also modeled. This HFT and

P

n
,
ℓ

are demonstrated for one- and many-electron atoms, plasmas and molecules using both analytical and numerical methods. Their applicability in several other confined systems is discussed from simple arguments.
Single underwater image restoration based on color correction and optimized transmission map estimation
Authors: Ke Ke , Zhang Chunmin , Wang Yanqiang , Zhang Yujiao , Yao Baoli
Published: January 2023

Underwater images often suffer from color distortion and resolution degradation due to the absorption and scattering of light. To deal with these problems, a novel underwater image restoration framework was designed to remove color deviation and background scattering successively. Firstly, an effective color correction method based on Lab color space is adopted to remove the color cast. Secondly, the color, saturation, and detail information are considered comprehensively to construct the scene depth map and edge map to estimate the transmission, and the relationship between the scattering coefficient and wavelength is used to modify the transmission map of each channel. In addition, a weighted least squares filter with adaptive smoothing parameters is introduced to estimate the local background light, which is applicable to the underwater scene with complex scattering. The experimental results show that the method performs better in color correction and detail enhancement, and the image quality is significantly improved.
3D printed negative stiffness meta-structures with superior energy absorption and super-elastic shape-recovery features
Authors: Hosseinabadi M , Etemadi E , Serjouei A , Bodaghi M
Published: January 2023

The aim of this paper is to create novel 3D cubic negative stiffness (NS) structures (NSSs) with superior mechanical performances such as high energy absorption, shape recovery, super-elasticity, and reversibility. The conceptual design is based on an understanding of geometrical influences, non-linear buckling-type instability, snap-through mechanism, elasto-plastic deformation growth and plastic hinges. A finite element (FE) based computational model with an elasto-plastic material behavior is developed to design and analyze NSSs, saving time, material, and energy consumption. Material samples and meta-structures are 3D printed by selective laser sintering printing method. Material properties are determined via mechanical testing revealing that the printing process does not introduce much anisotropy into the fabricated parts. Experimental tests are then conducted to study the behavior of novel designs under loading–unloading cycles verifying the accuracy of the computational model. A good correlation is observed between experimental and numerical data revealing the high accuracy of the FE modeling. The structural model is then implemented to digitally design and test NSSs. Effects of the geometrical parameters of the negative stiffness members under three cyclic loading are investigated, and their implications on the non-linear mechanical behavior of NSSs under cyclic loading are put into evidence, and pertinent conclusions are outlined. In addition, the dissipated energy and loss factor values of the designed structures are studied and the proposed unit cell is presented for the energy absorbing systems. The results show that the structural and geometry of energy absorbers are key parameters to improve the energy absorption capability of the designed structures. This paper is likely to fill a gap in the state-of-the-art NS meta-structures and provide guidelines that would be instrumental in the design of NSS with superior energy absorption, super-elasticity and reversibility features.
An audio-tactile interface based on dielectric elastomer actuators
Authors: Gratz-Kelly Sebastian , Krüger Tim , Rizzello Gianluca , Seelecke Stefan , Moretti Giacomo
Published: January 2023

This paper presents a concept of a dielectric elastomer actuator (DEA) user interface (smart button) that can sense a user’s touch and provide multi-sensory tactile and acoustic feedbacks through a single electrical input signal. The DEA relies on a multi-layer layout, in which a layer detects user-driven deformations (touches) via custom-built capacitance sensing electronics, and the remaining layers are used to provide actuation (audio-tactile feedbacks). Building upon a recently presented principle, combined tactile and acoustic feedbacks are produced by concurrently exciting different vibration modes of the same active membrane over different frequency ranges. An integrated demonstrator setup is presented, which includes a DEA, an acoustic enclosure, compact sensing and driving electronics. A characterization of the prototype is conducted, including an analysis of the sound pressure level, the force/stroke output at lower working frequencies, the ability to sense deformations with different profiles and produce combined audio-tactile outputs. Compared to previous works on multi-function DEAs, the system presented in this paper provides largely improved sensing performance (with lower working voltage) and features a deeper level of integration (with small-scale custom sensing electronics, and logics embedded onto scalable microcontrollers) and is thus specifically optimised for user-interaction applications. On this end, tests with users are presented here for the first time, which allowed evaluating the subjective perception of the interface’s feedbacks. By means of further optimisation and miniaturisation of the power/sensing electronics and structural components, the layout and multifunction DEA principle presented here might lead, in the future, to the development of DEA-based smart buttons for active surfaces, or portable/wearable user interfaces and communicators.
Closed-loop vasculature network design for bioprinting large, solid tissue scaffolds
Authors: Kumar Hitendra , Dixit Kartikeya , Sharma Rohan , MacDonald M Ethan , Sinha Niraj , Kim Keekyoung
Published: January 2023

Vascularization is an indispensable requirement for fabricating large solid tissues and organs. The natural vasculature derived from medical imaging modalities for large tissues and organs are highly complex and convoluted. However, the present bioprinting capabilities limit the fabrication of such complex natural vascular networks. Simplified bioprinted vascular networks, on the other hand, lack the capability to sustain large solid tissues. This work proposes a generalized and adaptable numerical model to design the vasculature by utilizing the tissue/organ anatomy. Starting with processing the patient’s medical images, organ structure, tissue-specific cues, and key vasculature tethers are determined. An open-source abdomen magnetic resonance image dataset was used in this work. The extracted properties and cues are then used in a mathematical model for guiding the vascular network formation comprising arterial and venous networks. Next, the generated three-dimensional networks are used to simulate the nutrient transport and consumption within the organ over time and the regions deprived of the nutrients are identified. These regions provide cues to evolve and optimize the vasculature in an iterative manner to ensure the availability of the nutrient transport throughout the bioprinted scaffolds. The mass transport of six components of cell culture media—glucose, glycine, glutamine, riboflavin, human serum albumin, and oxygen was studied within the organ with designed vasculature. As the vascular structure underwent iterations, the organ regions deprived of these key components decreased significantly highlighting the increase in structural complexity and efficacy of the designed vasculature. The numerical method presented in this work offers a valuable tool for designing vascular scaffolds to guide the cell growth and maturation of the bioprinted tissues for faster regeneration post bioprinting.
Three-dimensional bioprinted BMSCs-laden highly adhesive artificial periosteum containing gelatin-dopamine and graphene oxide nanosheets promoting bone defect repair
Authors: Sun Xin , Yang Jin , Ma Jie , Wang Tianchang , Zhao Xue , Zhu Dan , Jin Wenjie , Zhang Kai , Sun Xuzhou , Shen Yuling , Xie Neng , Yang Fei , Shang Xiushuai , Li Shuai , Zhou Xiaojun , He Chuanglong , Zhang Deteng , Wang Jinwu
Published: January 2023

The periosteum is a connective tissue membrane adhering to the surface of bone tissue that primarily provides nutrients and regulates osteogenesis during bone development and injury healing. However, building an artificial periosteum with good adhesion properties and satisfactory osteogenesis for bone defect repair remains a challenge, especially using three-dimensional (3D) bioprinting. In this study, dopamine was first grafted onto the molecular chain of gelatin using N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide (NHS) to activate the carboxyl group and produce modified gelatin-dopamine (GelDA). Next, a methacrylated gelatin, methacrylated silk fibroin, GelDA, and graphene oxide nanosheet composite bioink loaded with bone marrow mesenchymal stem cells was prepared and used for bioprinting. The physicochemical properties, biocompatibility, and osteogenic roles of the bioink and 3D bioprinted artificial periosteum were then systematically evaluated. The results showed that the developed bioink showed good thermosensitivity and printability and could be used to build 3D bioprinted artificial periosteum with satisfactory cell viability and high adhesion. Finally, the 3D bioprinted artificial periosteum could effectively enhance osteogenesis both in vitro and in vivo. Thus, the developed 3D bioprinted artificial periosteum can prompt new bone formation and provides a promising strategy for bone defect repair.
Effects of three patterns of elevated CO2 in single and multiple generations on photosynthesis and stomatal features in rice
Authors: Yang Kai , Huang Yao , Yang Jingrui , Lv Chunhua , Hu Zhenghua , Yu Lingfei , Sun Wenjuan
Published: January 2023

Background and Aims

Effects of elevated CO2 (E) within a generation on photosynthesis and stomatal features have been well documented in crops; however, long-term responses to gradually elevated CO2 (Eg) and abruptly elevated CO2 (Ea) over multiple generations remain scarce.

Methods

Japonica rice plants grown in open-top chambers were tested in the first generation (F1) under Ea and in the fifth generation (F5) under Eg and Ea, as follows: Ea in F1: ambient CO2 (A) + 200 μmol mol−1; Eg in F5: an increase of A + 40 μmol mol−1 year−1 until A + 200 μmol mol−1 from 2016 to 2020; Ea in F5: A + 200 μmol mol−1 from 2016 to 2020. For multigenerational tests, the harvested seeds were grown continuously in the following year in the respective CO2 environments.

Key Results

The responses to Ea in F1 were consistent with the previous consensus, such as the occurrence of photosynthetic acclimation, stimulation of photosynthesis, and downregulation of photosynthetic physiological parameters and stomatal area. In contrast, multigenerational exposure to both Eg and Ea did not induce photosynthetic acclimation, but stimulated greater photosynthesis and had little effect on the photosynthetic physiology and stomatal traits. This suggests that E retained intergenerational effects on photosynthesis and stomatal features and that there were no multigenerational differences in the effects of Eg and Ea.

Conclusions

The present study demonstrated that projecting future changes induced by E based on the physiological responses of contemporary plants could be misleading. Thus, responses of plants to large and rapid environmental changes within a generation cannot predict the long-term response of plants to natural environmental changes over multiple generations, especially in annual herbs with short life cycles.
MFR-DTA: a multi-functional and robust model for predicting drug–target binding affinity and region
Authors: Hua Yang , Song Xiaoning , Feng Zhenhua , Wu Xiaojun
Published: January 2023

Motivation

Recently, deep learning has become the mainstream methodology for drug–target binding affinity prediction. However, two deficiencies of the existing methods restrict their practical applications. On the one hand, most existing methods ignore the individual information of sequence elements, resulting in poor sequence feature representations. On the other hand, without prior biological knowledge, the prediction of drug–target binding regions based on attention weights of a deep neural network could be difficult to verify, which may bring adverse interference to biological researchers.

Results

We propose a novel Multi-Functional and Robust Drug–Target binding Affinity prediction (MFR-DTA) method to address the above issues. Specifically, we design a new biological sequence feature extraction block, namely BioMLP, that assists the model in extracting individual features of sequence elements. Then, we propose a new Elem-feature fusion block to refine the extracted features. After that, we construct a Mix-Decoder block that extracts drug–target interaction information and predicts their binding regions simultaneously. Last, we evaluate MFR-DTA on two benchmarks consistently with the existing methods and propose a new dataset, sc-PDB, to better measure the accuracy of binding region prediction. We also visualize some samples to demonstrate the locations of their binding sites and the predicted multi-scale interaction regions. The proposed method achieves excellent performance on these datasets, demonstrating its merits and superiority over the state-of-the-art methods.

Availability and implementation

https://github.com/JU-HuaY/MFR.
The adapted Activity-By-Contact model for enhancer–gene assignment and its application to single-cell data
Authors: Hecker Dennis , Behjati Ardakani Fatemeh , Karollus Alexander , Gagneur Julien , Schulz Marcel H
Published: January 2023

Motivation

Identifying regulatory regions in the genome is of great interest for understanding the epigenomic landscape in cells. One fundamental challenge in this context is to find the target genes whose expression is affected by the regulatory regions. A recent successful method is the Activity-By-Contact (ABC) model which scores enhancer–gene interactions based on enhancer activity and the contact frequency of an enhancer to its target gene. However, it describes regulatory interactions entirely from a gene’s perspective, and does not account for all the candidate target genes of an enhancer. In addition, the ABC model requires two types of assays to measure enhancer activity, which limits the applicability. Moreover, there is neither implementation available that could allow for an integration with transcription factor (TF) binding information nor an efficient analysis of single-cell data.

Results

We demonstrate that the ABC score can yield a higher accuracy by adapting the enhancer activity according to the number of contacts the enhancer has to its candidate target genes and also by considering all annotated transcription start sites of a gene. Further, we show that the model is comparably accurate with only one assay to measure enhancer activity. We combined our generalized ABC model with TF binding information and illustrated an analysis of a single-cell ATAC-seq dataset of the human heart, where we were able to characterize cell type-specific regulatory interactions and predict gene expression based on TF affinities. All executed processing steps are incorporated into our new computational pipeline STARE.

Availability and implementation

The software is available at https://github.com/schulzlab/STARE

Contact

marcel.schulz@em.uni-frankfurt.de

Supplementary information

Supplementary data are available at Bioinformatics online.
Benchmarking tools for a priori identifiability analysis
Authors: Rey Barreiro Xabier , Villaverde Alejandro F
Published: January 2023

Motivation

The theoretical possibility of determining the state and parameters of a dynamic model by measuring its outputs is given by its structural identifiability and its observability. These properties should be analysed before attempting to calibrate a model, but their a priori analysis can be challenging, requiring symbolic calculations that often have a high computational cost. In recent years, a number of software tools have been developed for this task, mostly in the systems biology community. These tools have vastly different features and capabilities, and a critical assessment of their performance is still lacking.

Results

Here, we present a comprehensive study of the computational resources available for analysing structural identifiability. We consider 13 software tools developed in 7 programming languages and evaluate their performance using a set of 25 case studies created from 21 models. Our results reveal their strengths and weaknesses, provide guidelines for choosing the most appropriate tool for a given problem and highlight opportunities for future developments.

Availability and implementation

https://github.com/Xabo-RB/Benchmarking_files.