bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the Effect of a COVID-19 Predictive Model to Facilitate Discharge: A Randomized Controlled Trial
Authors: Major Vincent J. , Jones Simon A. , Razavian Narges , Bagheri Ashley , Mendoza Felicia , Stadelman Jay , Horwitz Leora I. , Austrian Jonathan , Aphinyanaphongs Yindalon
Published: July 2022

Background We previously developed and validated a predictive model to help clinicians identify hospitalized adults with coronavirus disease 2019 (COVID-19) who may be ready for discharge given their low risk of adverse events. Whether this algorithm can prompt more timely discharge for stable patients in practice is unknown.

Objectives The aim of the study is to estimate the effect of displaying risk scores on length of stay (LOS).

Methods We integrated model output into the electronic health record (EHR) at four hospitals in one health system by displaying a green/orange/red score indicating low/moderate/high-risk in a patient list column and a larger COVID-19 summary report visible for each patient. Display of the score was pseudo-randomized 1:1 into intervention and control arms using a patient identifier passed to the model execution code. Intervention effect was assessed by comparing LOS between intervention and control groups. Adverse safety outcomes of death, hospice, and re-presentation were tested separately and as a composite indicator. We tracked adoption and sustained use through daily counts of score displays.

Results Enrolling 1,010 patients from May 15, 2020 to December 7, 2020, the trial found no detectable difference in LOS. The intervention had no impact on safety indicators of death, hospice or re-presentation after discharge. The scores were displayed consistently throughout the study period but the study lacks a causally linked process measure of provider actions based on the score. Secondary analysis revealed complex dynamics in LOS temporally, by primary symptom, and hospital location.

Conclusion An AI-based COVID-19 risk score displayed passively to clinicians during routine care of hospitalized adults with COVID-19 was safe but had no detectable impact on LOS. Health technology challenges such as insufficient adoption, nonuniform use, and provider trust compounded with temporal factors of the COVID-19 pandemic may have contributed to the null result.

Trial registration ClinicalTrials.gov identifier: NCT04570488.
Medial Malleolar Fracture Management—A Comparative Study of Radiological Outcome between Open Reduction Internal Fixation and Closed Reduction Percutaneous Fixation
Authors: Ethiraj Prabhu , Venkataraman Sagar , Shanthappa Arun Heddur , Agrawal Sandesh
Published: July 2022

Background

Medial malleolus fracture is commonly seen nowadays in orthopaedic practice. There are different modalities of treatment based on fracture pattern and socioeconomic status. Undisplaced fracture can be managed by cast application. Various surgical modalities of treatment are available in treating medial malleolus fracture like tension band wiring, cancellous screw or cortical screw fixation, plate fixation, Kirschner wire, and suture anchors. The purpose of our study was to evaluate radiological outcome of medial malleolus fracture managed with open reduction internal fixation and closed reduction percutaneous fixation.

Materials and Methods

Our study included 67 patients who met inclusion criteria and were divided into two groups. Group 1 included 52 patients with medial malleolar fractures cases and were treated with open reduction and internal fixation either by cancellous screw fixation or tension band wiring. Other 15 patients in group 2 were treated by closed reduction and internal fixation with cannulated cancellous screw. All postoperative patients were evaluated at 1st month, 2nd month, 3rd month, 6th month, and 1 year. We evaluated patient clinically and radiological union of fractures.

Results

In our study out of 67 patients there was male preponderance and average age was 46.55 years. Right-side fractures were more compared with left-side fractures. Most common mode of injury was road traffic accident. Transverse fracture pattern was more in number in our study. Average union time in group 1 was 13.46 weeks and group 2 is 15.14 weeks. Fracture union was 96.15% in group 1 and in group 2 was 93.33%.

Conclusion

In our study, average radiological union time in patients treated with open reduction internal fixation was early compared with percutaneous fixation. This could be due to direct visualization of fracture site and good approximation of fracture fragments in open reduction internal fixation technique.
Optimization of low-pass filters in a flux transformer of a SQUID magnetometer for MCG studies
Authors: Sutkovyi P. , Minov Yu. , Shpylovyi P. , Melnyk Ye. , Mudrenko M.
Published: July 2022

Research and optimization of a passive low-pass filter (LPF) for a magnetic flux transformer of superconducting quantum interferometric detector (SQUID) operating in a magnetocardiographic (MCG) system, in an unshielded room, under the influence of electromagnetic interference of significant intensity have been carried out. The amplitude-frequency characteristics (AFC) of the LPF in the SQUID magnetic flux transformer are calculated for various shunt circuits, including the LPF circuit recommended by “Supracon” group for its CE2 blue model of the SQUID. The analysis of LPF circuits and their frequency response are carried out in order to ensure maximum protection of the input circuits of the SQUID from the effects of electromagnetic interference. It is shown that the optimal LPF for the MCG system is a filter with an active resistance of about 1 Ω in the shunt circuit of magnetic flux transformer. The performed calculations of the LPF intrinsic noise in the SQUID magnetic flux transformer showed that the additional noise of the shunt circuit with a 1 Ω resistor is significantly less than external noise for MCG system operating in unshielded rooms in the industrial city.
Study of magnetoelastic interaction in MnF2 by the acoustoelectric transformation method
Authors: Bilych I. V. , Zhekov K. R. , Haidamak T. N. , Zvyagina G. A. , Fil D. V. , Fil V. D.
Published: July 2022

The mechanisms of magnetoelastic interaction in MnF2 are studied using the method of acoustoelectric transformation. The temperature dependence of the piezomagnetic coupling coefficient and its anisotropy were determined in the antiferromagnetic phase. We observe a new effect consisting in the appearance of a non-diagonal component of the magnetic susceptibility tensor, which is proportional to the square of the order parameter, under the action of the shear wave. A phenomenological interpretation of the effect, which takes into account a small-angle rotation of the crystal lattice, is presented. In the paramagnetic state, the effect of acoustic deformation is reduced to the modulation of the diagonal component of the susceptibility tensor.
Excluding selfish people results in more overall cooperation
Authors: Thompson Avery
Published: July 2022

In the public goods game, introducing global exclusion deters players from free riding.
Dynamical states and bifurcations in coupled thermoacoustic oscillators
Authors: Srikanth Sneha , Pawar Samadhan A. , Manoj Krishna , Sujith R. I.
Published: July 2022

The emergence of rich dynamical phenomena in coupled self-sustained oscillators, primarily synchronization and amplitude death, has attracted considerable interest in several fields of science and engineering. Here, we present a comprehensive theoretical study on the manifestation of these exquisite phenomena in a reduced-order model of two coupled Rijke tube oscillators, which are prototypical thermoacoustic oscillators. We characterize the dynamical behaviors of two such identical and non-identical oscillators by varying both system parameters (such as the uncoupled amplitudes and the natural frequencies of the oscillators) and coupling parameters (such as the coupling strength and the coupling delay). The present model captures all the dynamical phenomena—namely, synchronization, phase-flip bifurcation, amplitude death, and partial amplitude death—observed previously in experiments on coupled Rijke tubes. By performing numerical simulations and deriving approximate analytical solutions, we systematically decipher the conditions and the bifurcations underlying the aforementioned phenomena. The insights provided by this study can be used to understand the interactions between multiple cans in gas turbine combustors and develop control strategies to avert undesirable thermoacoustic oscillations in them.
Femtosecond laser-induced sub-wavelength plasma inside dielectrics. II. Second-harmonic generation
Authors: Ardaneh Kazem , Hassan Mostafa , Morel Benoit , Meyer Remi , Giust Remo , Couairon Arnaud , Bonnaud Guy , Courvoisier Francois
Published: July 2022

Second-harmonic emission at a frequency that is twice the laser frequency is an important diagnostic for nonlinear laser–plasma interaction. It is forbidden for centrosymmetric materials such as the bulk of sapphire. The symmetry, however, can be broken by dielectric discontinuities as a result of plasma generation inside a solid dielectric. In the present work, we explore the basic characteristics of experimentally observed second-harmonic emission during focusing a femtosecond Bessel beam inside sapphire. We employ three-dimensional particle-in-cell simulations and the Helmholtz wave equation for theoretical investigations. We analyze how the efficiency of second-harmonic generation and its polarization depend on the plasma parameters. We find that the second-harmonic is generated either due to the coalescence of two-surface electromagnetic waves or nonlinear interaction between the transverse electromagnetic wave and the longitudinal electron plasma wave driven by linear mode conversion. Experimental results agree with the theoretical predictions and confirm the existence of over-critical plasma inside the sapphire that is essential for the resonance of plasma waves or excitation of surface plasmons.
Spectral analysis on dissimilarity between turbulent momentum and heat transfers in plane Couette turbulence
Authors: Kawata T. , Tsukahara T.
Published: July 2022

Nonlinear interactions between different scales in turbulence result in both interscale and spatial transport of turbulent energy, and their role in the turbulent heat transfer mechanism is also of practical importance from an engineering viewpoint. In this study, we investigate a turbulent plane Couette flow with passive-scalar heat transfer at the Prandtl number of 0.71 to discuss the similarity/difference between scale interactions in velocity and temperature fields. The constant-temperature-difference boundary condition is used so that the mean velocity and temperature profiles are similar, and then, the roles of interscale and spatial transports are compared for the spectral transport budgets of turbulent energies and temperature-related statistics. We show that turbulent heat transfer occurs at relatively small streamwise length scales compared to momentum transfer, although molecular diffusion is more significant in the temperature field as the Prandtl number is less than 1. Detailed analysis on the transport budgets of temperature-related spectra shows that scale interactions in the temperature field supply more energy to small scales than those in the velocity field. This significant temperature cascade causes more energetic temperature fluctuation at small scales, resulting in the spectral dissimilarity between turbulent heat and momentum transfers.
Interactions of nitric oxide molecules with pure and oxidized silver clusters Agn±/AgnO± (n=11–13): A computational study
Authors: Fernández Eva M. , Balbás Luis C.
Published: July 2022

In this work, we have studied, within density functional theory, the interaction of NO with pure and oxidized silver clusters, both anionic and cationic, composed from 11 to 13 Ag atoms. In that size interval, shell closing effects are not expected, and structural and electronic odd–even effects will determine the strength of interaction. First, we obtained that species Agn± and AgnO± with odd number of electrons (n = 12) adsorb NO with higher energy than their neighbors (n = 11 and 13). This result is in agreement with the facts observed in recent mass spectroscopy measurements, which were performed, however, at finite temperature. The adsorption energy is about twice for oxidized clusters compared to pure ones and higher for anions than for cations. Second, the adsorption of another NO molecule on AgnNO± forms Agn(NO)2±, with the dimer (NO)2 in cis configuration, and binding the two N atoms with two neighbor Ag atoms. The n = 12 species show the higher adsorption energy again. Third, in the absence of reaction barriers, all complexes Agn(NO)2± dissociate spontaneously into AgnO± and N2O, except the n = 12 anion. The maximum high barrier along the dissociation path of Ag13(NO)2− is about 0.7 eV. Further analysis of projected density of states for Ag11−13(NO)x± (x = 0, 1, 2) molecules shows that bonding between NO and Ag clusters mainly occurs in the energy range between −3.0 and 3.0 eV. The overlap between 4d of Ag and 2p of N and O is larger for Ag12(NO)2± than for neighbor sizes. For n = 12, the d bands are close to the (NO)2 2π orbital, leading to extra back-donation charge from the 4d of Ag to the closer 2π orbital of (NO)2.
Assessing serial dependence in ordinal patterns processes using chi-squared tests with application to EEG data analysis
Authors: Yamashita Rios de Sousa Arthur Matsuo , Hlinka Jaroslav
Published: July 2022

We extend Elsinger’s work on chi-squared tests for independence using ordinal patterns and investigate the general class of m-dependent ordinal patterns processes, to which belong ordinal patterns processes derived from random walk, white noise, and moving average processes. We describe chi-squared asymptotically distributed statistics for such processes that take into account necessary constraints on ordinal patterns probabilities and propose a test for m-dependence, with which we are able to quantify the range of serial dependence in a process. We apply the test to epilepsy electroencephalography time series data and observe shorter m-dependence associated with seizures, suggesting that the range of serial dependence decreases during those events.
A simple topological model for two coupled neurons
Authors: Zhang Xu , Chen Guanrong
Published: July 2022

A simple topological model describing the chaotic dynamics of two coupled neurons is established and analyzed based on the Smale horseshoe theory.
An energy conserving mechanism for temporal metasurfaces
Authors: Deshmukh Kshiteej J. , Milton Graeme W.
Published: July 2022

Changing the microstructure properties of a space–time metamaterial while a wave is propagating through it, in general, requires addition or removal of energy, which can be of an exponential form depending on the type of modulation. This limits the realization and application of space–time metamaterials. We resolve this issue by introducing a mechanism of conserving energy at temporal metasurfaces in a non-linear setting. The idea is first demonstrated by considering a wave-packet propagating in a discrete medium of a one-dimensional (1D) chain of springs and masses, where using our energy conserving mechanism, we show that the spring stiffness can be incremented at several time interfaces and the energy will still be conserved. We then consider an interesting application of time-reversed imaging in 1D and two-dimensional (2D) spring–mass systems with a wave packet traveling in the homogenized regime. Our numerical simulations show that, in 1D, when the wave packet hits the time-interface, two sets of waves are generated, one traveling forward in time and the other traveling backward. The time-reversed waves re-converge at the location of the source, and we observe its regeneration. In 2D, we use more complicated initial shapes and, even then, we observe regeneration of the original image or source. Thus, we achieve time-reversed imaging with conservation of energy in a non-linear system. The energy conserving mechanism can be easily extended to continuum media. Some possible ideas and concerns in experimental realization of space–time media are highlighted in conclusion and in the supplementary material.
Replicator dynamics of public goods games with global exclusion
Authors: Wang Xiaofeng , Perc Matjaž
Published: July 2022

Studies to date on the role of social exclusion in public cooperation have mainly focused on the peer or pool sanctioning types of excluding free-riders from the share of common goods. However, the exclusive behaviors are not necessarily performed by individuals or local organizations but may rather be implemented by a centralized enforcement institution at a global scale. Besides, previous modeling methods of either peer or pool exclusion often presuppose some particular forms of feedback between the individual or collective efforts and the efficiency of social exclusion and, therefore, cannot comprehensively evaluate their effects on the evolution of cooperation in the social dilemma situations. Here, we construct a general model of global exclusion by considering the successful construction of the centralized exclusive institution as an arbitrary non-decreasing and smooth function of the collective efforts made by the global excluders and then theoretically analyze its potential impacts in the replicator dynamics of the public goods game. Interestingly, we have shown that, despite the presence of both the first- and second-order free-riding problems, global exclusion can indeed lead to the emergence or even stabilization of public cooperation without the support of any other evolutionary mechanism. In addition, we have also observed rich dynamical behaviors, such as the occurrence of a global or local family of neutrally stable closed orbits revolving around a nonlinear center or the existence of stable heteroclinic cycles between defectors, cooperators as well as global excluders, which give rise to a classification of up to 21 different phases.
Focusing of inertial waves by a vertically annular forcing
Authors: Liu J. , Oberlack M. , Wang Y. , Delache A. , Godeferd F. S.
Published: July 2022

A theory of inertial wave focusing generated by a vertically oscillating slender torus immersed in a uniformly rotating fluid is presented. The analytical solution of the velocity field shows that, under an axisymmetric annular forcing in inviscid rotating fluid, the wave rays form a double cone symmetric about the plane on which the torus is located. At the two vertices of the double cone, the waves are in a shock-like manner focus causing localized surges of energy. After focusing, the waves continue their propagation and form a new inverted cone with the same cone angle, such that both cones are symmetric about the focal point. These results are in good agreement with the experimental and numerical study by Duran-Matute et al. [Phys. Rev. E 87, 041001(R) (2013)]. When friction effects occur, the wave pattern changes substantially and the wave away from the focal point is significantly attenuated so that the symmetry about the focal point is broken. As a consequence, the wave beam widens and the focusing effect becomes weaker with increasing Ekman number (Ek), which indicates the ratio of the viscous force to the Coriolis force. Furthermore, for the same Ek, the focusing effect tends to disappear when the forcing frequency is close to zero or twice the angular velocity of rotating flow. For forcing frequency close to the angular velocity of a rotating fluid, the amplitude of the vertical velocity at the focal point reaches its maximum, which corresponds to a wave propagation angle of 60 degrees.
Impact of dislocation density on the ferroelectric properties of ScAlN grown by molecular beam epitaxy
Authors: Wang Ding , Wang Ping , Mondal Shubham , Xiao Yixin , Hu Mingtao , Mi Zetian
Published: July 2022

We report on the effect of dislocation density on the ferroelectric properties of single-crystalline ScAlN thin films grown by molecular beam epitaxy. Wurtzite phase and atomically smooth ScAlN films have been grown on bulk GaN, GaN on sapphire, and GaN on Si substrates with dislocation densities ranging from ∼107 to 1010 cm−2. Despite the significant difference in dislocation density, ferroelectricity is observed in all three samples. The presence of high densities of dislocations, however, results in enhanced asymmetric P–E loops and overestimated remnant polarization values. Further measurements show that the leakage current and breakdown strength can be improved with decreasing dislocation density. Detailed studies suggest that trapping/detrapping assisted transport is the main leakage mechanism in epitaxial ferroelectric ScAlN films. This work sheds light on the essential material quality considerations for tuning the ferroelectric property of ScAlN toward integration with mainstream semiconductor platforms, e.g., Si, and paves the way for next-generation electronics, optoelectronics, and piezoelectronics.
Computational study of inertial migration of prolate particles in a straight rectangular channel
Authors: Lauricella Giuseppe , Zhou Jian , Luan Qiyue , Papautsky Ian , Peng Zhangli
Published: July 2022

Inertial migration of spherical particles has been investigated extensively using experiments, theory, and computational modeling. Yet, a systematic investigation of the effect of particle shape on inertial migration is still lacking. Herein, we numerically mapped the migration dynamics of a prolate particle in a straight rectangular microchannel using smoothed particle hydrodynamics at moderate Reynolds number flows. After validation, we applied our model to 2:1 and 3:1 shape aspect ratio particles at multiple confinement ratios. Their effects on the final focusing position, rotational behavior, and transitional dynamics were studied. In addition to the commonly reported tumbling motion, for the first time, we identified a new logrolling behavior of a prolate ellipsoidal particle in the confined channel. This new behavior occurs when the confinement ratio is above an approximate threshold value of K = 0.72. Our microfluidic experiments using cell aggregates with similar shape aspect ratio and confinement ratio confirmed this new predicted logrolling motion. We also found that the same particle can undergo different rotational modes, including kayaking behavior, depending on its initial cross-sectional position and orientation. Furthermore, we examined the migration speed, angular velocity, and rotation period as well as their dependence on both particle shape aspect ratio and confinement ratio. Our findings are especially relevant to the applications where particle shape and alignment are used for sorting and analysis, such as the use of barcoded particles for biochemical assays through optical reading, or the shape-based enrichment of microalgae, bacteria, and chromosomes.
Unsteady aerodynamic prediction for iced airfoil based on multi-task learning
Authors: Wang Xu , Kou Jiaqing , Zhang Weiwei
Published: July 2022

Ice accretion on wind turbine blades and wings changes the effective shape of the airfoil and considerably deteriorates the aerodynamic performance. However, the unsteady performance of iced airfoil is often difficult to predict. In this study, the unsteady aerodynamic performance of iced airfoil is simulated under different pitching amplitudes and reduced frequencies. In order to efficiently predict aerodynamic performance under icing conditions, a multi-fidelity reduced-order model based on multi-task learning is proposed. The model is implemented using lift and moment coefficient of clean airfoil as low-fidelity data. Through using few aerodynamic data from iced airfoils as high-fidelity data, the model can achieve aerodynamic prediction for different ice shapes and pitching motions. The results indicate that, compared with single-fidelity and single-task modeling, the proposed model can achieve better accuracy and generalization capability. At the same time, the model can be generalized to different ice shapes, which can effectively improve the unsteady prediction efficiency.
Two-stage fourth-order subcell finite volume method on hexahedral meshes for compressible flows
Authors: Zhang Chao , Li Qibing , Song Peng , Li Jiequan
Published: July 2022

As an extension of the two-stage fourth-order subcell finite volume (SCFV) method that we developed for two-dimensional compressible flows [C. Zhang et al., “Two-stage fourth-order gas kinetic solver based compact subcell finite volume method for compressible flows on triangular meshes,” Phys. Fluids 33, 126108 (2021)], this study continues our efforts toward three-dimensional (3D) simulations on hexahedral meshes. The two components of subcell divisions and two-stage fourth-order time stepping are utilized to improve efficiency and enhance compactness, which are crucial for 3D simulations. In particular, the current method subdivides each cell into a set of subcells or control volumes (CVs) to increase the degrees of freedom for high-order reconstruction, which involves only face-neighboring cells. For traditional finite volume (FV) methods, high-order reconstruction is performed on each CV individually. In contrast, the reconstruction of SCFV is shared by a set of CVs belonging to the same cell, which can be much more efficient and compact. Moreover, the SCFV framework is combined with the high-order flux evolution by adopting a robust and time-dependent gas-kinetic flux solver and an efficient two-stage fourth-order temporal discretization. The multi-stage Runge–Kutta (RK) method is thus avoided. The coupling of inviscid and viscous terms in the gas-kinetic flux enables us to directly simulate viscous flows. To capture shocks, a limiting procedure by hierarchical reconstruction is developed for effectively preserving the accuracy in smooth flow regions and suppressing numerical oscillations near flow discontinuities. Several benchmark cases are tested. The high-order accuracy and efficiency of this scheme are validated and compared to the k-exact FV method and the traditional Riemann solver combined with a multi-stage RK method. In particular, the simulation of the supersonic Taylor–Green vortex problem demonstrates the good performance of this scheme in compressible turbulence with the presence of shock waves.
An optoelectronic heterostructure for neuromorphic computing: CdS/V3O5
Authors: Adda C. , Navarro H. , Kaur J. , Lee M.-H. , Chen C. , Rozenberg M. , Ong S. P. , Schuller Ivan K.
Published: July 2022

Nonvolatile resistive switching is one of the key phenomena for emerging applications in optoelectronics and neuromorphic computing. In most of the cases, an electric field is applied to a two terminal dielectric material device and leads to the formation of a low resistance filament due to ion migration. However, the stochastic nature of the ion migration can be an impediment for the device robustness and controllability, with uncontrolled variations of high and low resistance states or threshold voltages. Here, we report an optically induced resistive switching based on a CdS/V3O5 heterostructure which can overcome this issue. V3O5 is known to have a second order insulator to metal transition around Tc ≈ 415 K, with an electrically induced threshold switching at room temperature. Upon illumination, the direct transfer of the photoinduced carriers from the CdS into V3O5 produces a nonvolatile resistive switching at room temperature. The initial high resistance can be recovered by reaching the high temperature metallic phase, i.e., temperatures above Tc. Interestingly, this resistive switching becomes volatile around the Tc. By locally manipulating the volatile and nonvolatile resistive switching using electric field and light, this system is a promising platform for hardware based neuromorphic computing implementations.
Termination of pregnancy in Queensland post-decriminalisation: a content analysis of client records from an all-options pregnancy counselling organisation
Authors: Cleetus Maryanne , Lazarou Mattea , Tooker Siân , Jenkinson Bec , Dean Judith A.
Published: July 2022

Background Termination of pregnancy (ToP) was decriminalised in Queensland, Australia, in December 2018. Although approximately 14 000 terminations are performed in Queensland annually, decriminalisation had addressed a known barrier to ToP access by supporting the legal right to access and enabling safe and regulated public pathways to ToP care. The post-decriminalised ToP experience in Queensland is unknown. Therefore, this study explored the reported reasons clients access information and support from an all-options pregnancy counselling service in Queensland with the aim of identifying the facilitators and barriers accessing ToP that remain post-decriminalisation in Queensland. Methods A two-part qualitative conventional and directed content analysis approach guided by the Socioecological Model was used to examine counsellor notes on interactions with clients (n = 1933) between December 2018 and June 2020 at an all-options pregnancy counselling service in Queensland. Findings Key reasons for contacting the service were for financial assistance, ToP information, and support for decision making. Facilitators and barriers affecting ToP access interconnected across the Socioecological Model levels highlighting affordability, violence, stigma, knowledge, and information as key factors influencing ToP access post-decriminalisation in Queensland. Conclusions Inclusive multisectoral action to support reproductive autonomy is needed in Queensland. Following decriminalisation, cost, stigma, and intimate partner violence continue to impede access to safe, compassionate, and timely abortion care. Future models of care must eliminate these barriers by developing public models of service provision, investing in workforce development, fully utilising the capacity of that workforce, and creating stronger connections between sexual and reproductive health and intimate partner violence services.
Selective inhibition of protein secretion by abrogating receptor–coat interactions during ER export
Authors: Gomez-Navarro Natalia , Maldutyte Julija , Poljak Kristina , Peak-Chew Sew-Yeu , Orme Jonathon , Bisnett Brittany J. , Lamb Caitlin H. , Boyce Michael , Gianni Davide , Miller Elizabeth A.
Published: July 2022

Protein secretion is an essential process that drives cell growth, movement, and communication. Protein traffic within the secretory pathway occurs via transport intermediates that bud from one compartment and fuse with a downstream compartment to deliver their contents. Here, we explore the possibility that protein secretion can be selectively inhibited by perturbing protein–protein interactions that drive capture into transport vesicles. Human proprotein convertase subtilisin/kexin type 9 (PCSK9) is a determinant of cholesterol metabolism whose secretion is mediated by a specific cargo adaptor protein, SEC24A. We map a series of protein–protein interactions between PCSK9, its endoplasmic reticulum (ER) export receptor SURF4, and SEC24A that mediate secretion of PCSK9. We show that the interaction between SURF4 and SEC24A can be inhibited by 4-phenylbutyrate (4-PBA), a small molecule that occludes a cargo-binding domain of SEC24. This inhibition reduces secretion of PCSK9 and additional SURF4 clients that we identify by mass spectrometry, leaving other secreted cargoes unaffected. We propose that selective small-molecule inhibition of cargo recognition by SEC24 is a potential therapeutic intervention for atherosclerosis and other diseases that are modulated by secreted proteins.
Hydrodynamically induced helical particle drift due to patterned surfaces
Authors: Chase Danielle L. , Kurzthaler Christina , Stone Howard A.
Published: July 2022

Advances in microfabrication enable the tailoring of surfaces to achieve optimal sorting, mixing, and focusing of complex particulate suspensions in microfluidic devices. Corrugated surfaces have proved to be a powerful tool to manipulate particle motion for a variety of applications, yet the fundamental physical mechanism underlying the hydrodynamic coupling of the suspended particles and surface topography has remained elusive. Here, we study the hydrodynamic interactions between sedimenting spherical particles and nearby corrugated surfaces, whose corrugations are tilted with respect to gravity. Our experiments show three-dimensional, helical particle trajectories with an overall drift along the corrugations, which agree quantitatively with our analytical perturbation theory. The theoretical predictions reveal that the interaction of the disturbance flows, induced by the particle motion, with the corrugations generates locally a transverse anisotropy of the pressure field, which explains the helical dynamics and particle drift. We demonstrate that this dynamical behavior is generic for various surface shapes, including rectangular, sinusoidal, and triangular corrugations, and we identify surface characteristics that produce an optimal particle drift. Our findings reveal a universal feature inherent to particle transport near patterned surfaces and provide fundamental insights for future microfluidic applications that aim to enhance the focusing or sorting of particulate suspensions.
Secretion of functional α1-antitrypsin is cell type dependent: Implications for intramuscular delivery for gene therapy
Authors: Ke Haiping , Guay Kevin P. , Flotte Terence R. , Gierasch Lila M. , Gershenson Anne , Hebert Daniel N.
Published: July 2022

Heterologous expression of proteins is used widely for the biosynthesis of biologics, many of which are secreted from cells. In addition, gene therapy and messenger RNA (mRNA) vaccines frequently direct the expression of secretory proteins to nonnative host cells. Consequently, it is crucial to understand the maturation and trafficking of proteins in a range of host cells including muscle cells, a popular therapeutic target due to the ease of accessibility by intramuscular injection. Here, we analyzed the production efficiency for α1-antitrypsin (AAT) in Chinese hamster ovary cells, commonly used for biotherapeutic production, and myoblasts (embryonic progenitor cells of muscle cells) and compared it to the production in the major natural cells, liver hepatocytes. AAT is a target protein for gene therapy to address pathologies associated with insufficiencies in native AAT activity or production. AAT secretion and maturation were most efficient in hepatocytes. Myoblasts were the poorest of the cell types tested; however, secretion of active AAT was significantly augmented in myoblasts by treatment with the proteostasis regulator suberoylanilide hydroxamic acid, a histone deacetylase inhibitor. These findings were extended and validated in myotubes (mature muscle cells) where AAT was transduced using an adeno-associated viral capsid transduction method used in gene therapy clinical trials. Overall, our study sheds light on a possible mechanism to enhance the efficacy of gene therapy approaches for AAT and, moreover, may have implications for the production of proteins from mRNA vaccines, which rely on the expression of viral glycoproteins in nonnative host cells upon intramuscular injection.
From remote control to tweets
Authors: Arzık-Erzurumlu Özüm , Yilmaz Gamze
Published: July 2022

This study examined the role Twitter reactions play in (re)shaping the quality criteria in TV interpreting (TVI)
during the Oscars ceremony in Turkey, extending over a ten-year period. The secondary goal of this study was to shed light on the
extent to which tweets affected the interpreting practice, recruitment of interpreters, and the discourse about TVI in general.
The thematic analysis of the tweets showed that the viewers generally criticized interpreters based on their delivery, use of
voice, and word choices. Complementary interviews conducted with TV interpreters and one executive revealed that tweets were
instrumentalized by executives and recruiters both in real time and during the recruitment process; in this way they became a
quality instrument with which to evaluate TV interpreters’ performance. The findings are discussed in the light of the literature
on TVI and are used to advance both practical and theoretical implications for the practice of TVI.
Gravitational entropy in Szekeres class I models
Authors: Pizaña Fernando A , Sussman Roberto A , Hidalgo Juan Carlos
Published: July 2022

Developing a self-consistent notion of gravitational entropy in the context of cosmological structure formation has been so far an elusive task. Various theoretical proposals have been presented, initially based on Penrose’s Weyl curvature hypothesis, and variations of it. A more recent proposal by Clifton, Ellis, and Tavakol (CET) considered a novel approach by defining such entropy from a Gibbs equation constructed from an effective stress–energy tensor that emerges from the ‘square root’ algebraic decomposition of the Bel–Robinson tensor, the simplest divergence-less tensor related to the Weyl tensor. Since, so far all gravitational entropy proposals have been applied to highly restrictive and symmetric spacetimes, we probe in this paper the CET proposal for a class of much less idealized spacetimes (the Szekeres class I models) capable of describing the joint evolution of arrays of arbitrary number of structures: overdensities and voids, all placed on selected spatial locations in an asymptotic ΛCDM background. By using suitable covariant variables and their fluctuations, we find the necessary and sufficient conditions for a positive CET entropy production to be a negative sign of the product of the density and Hubble expansion fluctuations. To examine the viability of this theoretical result we examine numerically the CET entropy production for two elongated over dense regions surrounding a central spheroidal void, all evolving jointly from initial linear perturbations at the last scattering era into present day Mpc-size CDM structures. We show that CET entropy production is positive for all times after last scattering at the precise spatial locations where structure growth occurs and where the exact density growing mode is dominant. The present paper provides the least idealized (and most physically robust) probe of a gravitational entropy proposal in the context of structure formation.
Decreased trap density and lower current collapse in AlGaN/GaN HEMTs by adding a magnetron-sputtered AlN gate
Authors: Jia Mao , Zhang He-Nan , Wang Xiao , Liu Chen-Yang , Pu Tao-Fei , Wang Ting-Ting , He Yue , Jiang Feng-Qiu , Fang Ke , Yang Ling , Bu Yu-Yu , Li Yang , Ma Xiao-Hua , Ao Jin-Ping , Hao Yue
Published: July 2022

In this paper, AlN films grown by magnetron sputtering method have been proposed as the gate insulator layer of AlGaN/GaN high electron mobility transistors (HEMTs) to decrease gate leakage current and suppress the interface trap. The effect of the temperature of substrate on the quality of AlN films have been investigated. By inserting the thin AlN film (35 nm) as a gate insulator layer, the on-state resistance of AlGaN/GaN HEMTs decrease from 11.1 Ω mm to 10.3 Ω mm @V
g = 0 V, the current collapse decreases from 16.6% to 3.2%, the gate leakage can be reduced from 1.2 × 10−1A mm−1 to 4.4 × 10−6A mm−1 @V
g = 2 V by five orders of magnitude, and the fast interface states disappear and the normal trap density decreases from 0.96–1.3 × 1013 cm−2eV−1 to 1.3–3.4 × 1012 cm−2 eV−1, proving that magnetron-sputtered AlN is an effective way to improve the performance of GaN HEMTs.
Logical OR operation and magnetic field sensing based on layered topology
Authors: Sui Junyang , Zhang Dan , Zhang Haifeng
Published: July 2022

A one-dimensional magnetized InSb photonic crystals layered topology (PCLT) proposed in this paper can realize the functions of logic OR operation and magnetic field sensing. In the proposed PCLT, under the transverse magnetic polarization, the value and frequency of the absorption peak (AP) can be controlled by the external magnetic fields and has a high-quality factor (Q), thus OR logical operation can be achieved. Additionally, since InSb has a magneto-optical effect under magnetic fields, the parity of the structure of the PCLT which adds InSb as defect layers can be broken. Electromagnetic waves obtain nonreciprocity when propagating in opposite directions within the PCLT, which means that logical operation and magnetic field sensing based on AP can be obtained on the forward and backward scales. For the detection, on the forward scale, optimum performances of Q, sensitivity (S), the figure of merit, and detection limit are 62 372.09, 0.0169 (2πc/d)/T, 4225 T−1, 1.2 × 10−5 T, and for the backward detection, the corresponding values are 63 626.25, 0.0225 (2πc/d)/T, 5200 T−1, 1 × 10−5 T. The designed PCLT is innovative in multi-functional and multi-scale, having certain research value and prospects.
Transseptal versus retrograde approach for ablation of left-sided accessory pathways: impact on radiation exposure
Authors: Bouchiat Laetitia , Faroux Laurent , Chabert Jean-Pierre , Mauran Pierre , Blanpain Thierry , Metz Damien , Lesaffre François
Published: July 2022

Management of left-sided accessory pathways (APs) is based on catheter ablation through an antegrade or retrograde approach. Both are safe and effective but are associated with exposure to x-rays; however, recipients of ablation are generally young. We sought to evaluate the impact of the approach chosen on dose–area product (DAP). A total of 95 patients who underwent radiofrequency ablation of a left-sided AP between January 2011 and January 2020 were included. The primary endpoint was the radiation dose received by the patient. Secondary endpoints were procedural success and complication and recurrence rates. The mean age of the study population was 34.3 ± 16.6 years. The antegrade transseptal approach was used in 63.5% of cases. By multivariate analysis, the antegrade transseptal approach was associated with a 53% reduction in DAP (p < 0.001). The radiation dose received was also significantly associated with body mass index and total fluoroscopy time (p < 0.001). There was no significant difference in other secondary endpoints between approaches. The use of an antegrade transseptal approach is associated with a significant reduction in DAP compared with the retrograde approach, and procedural success and complication and recurrence rates are similar.
Direct synthesis of submillimeter-sized few-layer WS2 and WS0.3Se1.7 by mist chemical vapor deposition and its application to complementary MOS inverter
Authors: Kuddus Abdul , Yokoyama Kojun , Shirai Hajime
Published: July 2022

This study investigated the direct synthesis of submillimeter-sized few-layer tungsten disulfide (WS2) and tungsten sulfoselenide (WS0.3Se1.7) using the mist chemical vapor deposition (CVD) method as a channel layer for metal-oxide-semiconductor field-effect transistors (MOSFETs). The atomic mono/bilayers WS2 and WS2−x
Se
x
were deposited on thermally grown SiO2 and mist-CVD-grown high-κ amorphous aluminum titanium oxide coated on p+-Si substrates by an intermittent mist supply in a closed quartz tube from (NH4)2WS4 dissolved in N-methyl-2-pyrrolidone. Further, the furnace temperatures, supply/storage times of the precursor mist per cycle, and precursor concentration were considered variables. Consequently, few-layer WS2 and WS0.3Se1.7 with grain sizes of 700–800 μm were obtained on the high-κ a-Al0.74Ti0.26O
y
dielectric layers through adjustments to the deposition conditions. Subsequently, this few-layer WS2 and WS0.3Se1.7 were applied as channel layers in MOSFETs, which showed n- and p-channel behaviors using gold and platinum source/drain electrodes, respectively. Further, average mobilities of ∼52 and ∼41 cm2 V−1 s−1 were obtained with a threshold voltage of −0.2 (0.3) V and on-off ratios of ∼1 × 106 and ∼6 × 105 in n-WS2 and p-WS0.3Se1.7 channel FETs, respectively. Moreover, this n- and p-channel FETs were used to design an electrically isolated complementary inverter circuit, and a gain of 4–5 was obtained. The findings of this study suggest that mist CVD can be a consistent manufacturing technique for both the channel and gate insulating layers applied in FETs.
Characterization of traps in GaN-based HEMTs by drain voltage transient and capacitance deep-level transient spectroscopy
Authors: Pan Shijie , Feng Shiwei , Li Xuan , Bai Kun , Lu Xiaozhuang , Zhang Yamin , Zhou Lixing , Rui Erming , Jiao Qiang , Tian Yu
Published: July 2022

This paper presents a detailed investigation of trapping effect in AlGaN/GaN high-electron-mobility transistors based on the pulsed current–voltage characterization, drain voltage transient (DVT) measurement, and capacitance deep-level transient spectroscopy (C-DLTS). By monitoring the DVTs at various filling voltages and temperatures, the properties of three electron traps were obtained with the DVT measurements. Specifically, the energy levels of the former two traps were determined to be 0.28 and 0.48 eV, which was confirmed by the C-DLTS measurement performed on the same device. In addition, a third temperature-independent trap located in the GaN buffer was observed only with the DVT measurement, indicating the advantage of transient curves measurement in characterizing the traps insensitive to temperature. The combined measurements demonstrate the correlation of different techniques, which allows identifying the same trap levels to investigate the physical origin of traps.
A nonlinear time delay control influence in simulation aircraft tail contain a vertical cantilever beam
Authors: Bauomy H S , EL-Sayed A T
Published: July 2022

Nonlinear time delay saturation controller (NTDSC) is used to minimize the vibrations of a vertical cantilever beam simulated as an airplane tail within harmonic excitation force. In the case of primary and 1:2 internal resonance as a simultaneous resonance case, an analytic solution is obtained by employing the multiple time scale perturbation technique to solve the nonlinear differential equations and modeling the system with NTDSC. Time histories and Poincare portraits were created to demonstrate the system without and with controller. The time-history response, as well as the impacts of the parameters on the system and controller, were simulated numerically using the MATLAB program. A good match is found when the approximate solutions are compared to the numerical simulations via the Runge–Kutta method fourth-order (RK4). The stability investigation of the steady state solution in the studied simultaneous resonance case is reviewed and analyzed via the Routh-Huriwitz approach. The impact of controller parameters and time delays on system response curves are examined. Also, the operation’s safe zone is established from the outcomes of the effect via various values of time delays on the system after adding the control scheme. The numerical and analytical solutions at time-history were compared using the MATLAB program to confirm their comparability. The outcomes of this study were used to develop a theoretical foundation for the system’s design and construction. A comparison is made with recently released papers to appear the difference between this study and the others.