bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced dual branches network for arbitrary‐scale image super‐resolution
Authors: Li Guangping , Xiao Huanling , Liang Dingkai
Published: December 2022

Deep convolutional neural networks (CNNs) are of great improvement for single image super‐resolution (SISR). However, most existing SISR pre‐trained models can only perform single image restoration and the upscale factors cannot be non‐integers, which limits its application in real‐world scenarios. In this letter, an enhanced dual branches network (EDBNet) in upsampling network is proposed to generate arbitrary‐scale super‐resolution (SR) images. Specifically, the authors design a scale‐guidance upsampling module (SGU) by adding the scale factors and pixel‐level features to guide the weights of convolution. The SGU module performs discriminant learning for each instance in the same batch. Extensive experiments on four benchmark datasets show that the proposed method can achieve superior SR results.
Face anti‐spoofing from the perspective of data sampling
Authors: Muhammad Usman , Oussalah Mourad
Published: December 2022

Without deploying face anti‐spoofing countermeasures, face recognition systems can be spoofed by presenting a printed photo, a video, or a silicon mask of a genuine user. Thus, face presentation attack detection (PAD) plays a vital role in providing secure facial access to digital devices. Most existing video‐based PAD countermeasures lack the ability to cope with long‐range temporal variations in videos. Moreover, the key‐frame sampling prior to the feature extraction step has not been widely studied in the face anti‐spoofing domain. To mitigate these issues, this paper provides a data sampling approach by proposing a video processing scheme that models the long‐range temporal variations based on Gaussian weighting function (GWF). Specifically, the proposed scheme encodes the consecutive t frames of video sequences into a single RGB image based on a Gaussian‐weighted summation of the t frames. Using simply the data sampling scheme alone, it is demonstrated here that state‐of‐the‐art performance can be achieved without any bells and whistles in both intra‐database and inter‐database testing scenarios for the three public benchmark datasets; namely, replay‐Attack, MSU‐MFSD, and CASIA‐FASD. In particular, the proposed scheme provides a much lower error (from 15.2% to 7.6% on CASIA‐FASD and 5.9% to 4.9% on replay‐attack) compared to baselines in cross‐database scenarios.
Calculation of magnetic field and eddy current loss in end clamping ring of 300MVA synchronous condenser based on a novel semi‐analytical method
Authors: Zhu Erhang , Liang Yanping , Han Xiao , Bian Xu , Wang Dongmei
Published: December 2022

It is very important to consider the eddy current reaction of the metal structure in large electric machines, which has a direct impact on the calculation results of induced current and loss. In order to solve the problem that the complex end leakage magnetic field is difficult to calculate directly, a new semi‐analytical method (NSM) considering the eddy current reaction is proposed. Firstly, the corresponding relationship between the external magnetic field and the global magnetic field of the clamping ring in two simple calculation models is obtained by the 3‐D finite element method. Then, the external magnetic field of the clamping ring in a 300MVA synchronous condenser under rated operating conditions is calculated, and the global magnetic field of the clamping ring is determined based on the obtained corresponding relationship. The eddy current density and eddy current loss of the clamping ring are calculated using the external magnetic field and the global magnetic field respectively. Finally, the calculation results were compared with the 3‐D finite element results, which verified the importance of the global magnetic field and the accuracy of the NSM.
Study on resonance characteristic of continuous co‐phase traction power supply system
Authors: Zhong Fan , Xie Shaofeng
Published: December 2022

In order to solve the power quality problems and eliminate the neutral sections in the railway, the implementation of the continuous co‐phase traction power supply system (CCTPSS) is the development trend of the future. However, various parameters of the compensator in CCTPSS have a huge impact on the resonance, which will possibly change the original resonance characteristic of the railway. Therefore, the parameters design of the compensator has become a difficult problem to be solved. An optimization mode method is proposed in this paper to obtain the influence of the compensator on the resonance characteristic of CCTPSS and the optimal solution of each parameter is obtained with the goal of suppressing resonance and minimizing the cost. Firstly, the impedance analysis and transfer function analysis are used to establish models for CCTPSS. It is found that the equivalent harmonic impedance of the traction substation decreases after adding the compensator, which will inevitably cause the resonance frequency to increase. By comparing the resonance points of the original traction power supply system (TPSS) and CCTPSS, the results show that the parameters of the compensator have a greater influence on the resonance point in CCTPSS. At last, taking the CCTPSS based on LCL‐type reactive power comprehensive compensator (RPCC) as an example to carry out the optimization mode method, the result proves that this method is not only beneficial to the suppression of harmonic resonance, but also helpful for reducing the cost of the RPCC.
A 2D numerical study on collision coefficient of single conductor under direct current electric field
Authors: Chao Zhou , Jianfeng Sun
Published: December 2022

In early spring or winter, supercooled raindrops impact on transmission lines and accumulate ice on its surface frequently, which may induce galloping vibration occurs. Studies on collision coefficient or icing mostly focus on key parameters of wind velocities, raindrop sizes and conductor diameters, whereas few involve electric field. In order to clarify the influence of the direct current electric field on the collision coefficient of transmission lines, a calculation formula of the mass flow rate of raindrops was proposed, and the process of raindrops hitting the conductor surface is numerically calculated by the Euler–Lagrange method. The effects of electric field intensity, conductor diameter, cross‐sectional shape, wind velocity, raindrop diameter and charge density on the collision coefficient of transmission lines are analyzed. The results show that the collision coefficient decreases with the increase of electric intensity. As the electric intensity increases from 0  to 66.7 kV/cm, the collision coefficient decreases about 33%. Because of the repulsion between the conductor and raindrops, more raindrops move away from the conductor surface and collision coefficient decreases. The collision coefficient of the actual conductor under no electric field is slightly smaller than that of the simplified circular cross‐section. Under DC electric field, the collision coefficient of the conductor decreases with wind velocity increase up to 8 m/s. Beyond that threshold, the collision coefficient is almost constant.
A review of modelling techniques of power transformers for digital real‐time simulation
Authors: Islam Md Maidul , Musil Matthias , Shohan Md Jamal Ahmed , Faruque Md Omar , Lauss Georg , Dehkordi Ali , Forsyth Paul , Kotsampopoulos Panos , Strunz Kai , Li Zhihui , Zhang Yi , Liu Peng
Published: December 2022

This task‐force paper documents and summarizes the models of power transformers that have been proposed, used, and validated in the exercise of digital real‐time simulation. Power transformer is one of the most important equipment in power systems, and its modelling for electromagnetic transient simulation has evolved over time, especially in the area of real‐time simulation. The focus of the paper is to document and archive the models that have been well accepted and used for transient analysis in digital real‐time simulation so that readers can use it as a master document for transformer modelling in real‐time simulation studies. It includes both conventional and specialized models of power transformers that have been broadly acknowledged by the power engineering community. The models provided here come with detailed mathematical representation and their implementation techniques. A comparative study is also performed to illustrate the differences in their performances. In the end, an application guideline has been provided to guide the readers to select the appropriate model for their study.
A new resonance-like feature in the outer disc of the Milky Way
Authors: Drimmel R. , Khanna S. , D’Onghia E. , Tepper-García T. , Bland-Hawthorn J. , Chemin L. , Ripepi V. , Romero-Gómez M. , Ramos P. , Poggio E. , Andrae R. , Blomme R. , Cantat-Gaudin T. , Castro-Ginard A. , Clementini G. , Figueras F. , Fouesneau M. , Frémat Y. , Lobel A. , Marshall D. , Muraveva T.
Published: December 2022

Modern astrometric and spectroscopic surveys have revealed a wealth of structure in the phase space of stars in the Milky Way, with evidence of resonance features and non-equilibrium processes. Using the third Gaia data release, we present evidence of a new resonance-like feature in the outer disc of the Milky Way. The feature is most evident in the angular momentum distribution of the young classical Cepheids, a population for which we can derive accurate distances over much of the Galactic disc. We then searched for similar features in the outer disc using a much larger sample of red giant stars, as well as a compiled list of over 31 million stars with spectroscopic line-of-sight velocity measurements. While much less evident in these two older samples, the distribution of stars in action-configuration space suggests that resonance features are present here as well. The position of the feature in action-configuration space suggests that the new feature may be related to the Galactic bar, but other possibilities are discussed.
Herausforderungen der Tumorpathologie
Authors: Willen Christine
Published: December 2022

Im Zeitalter der Präzisionsmedizin ist die Verfügbarkeit hochwertiger Tumor-Biomarker-Tests mit nachgewiesener analytischer Validität und klinischem Nutzen von entscheidender Bedeutung. Eine aktuelle Herausforderung ist immer noch die Bestimmung des HER2-low-Status sowie altbekannte Herausforderungen wie die Befundung zu Ki67.
Großzelliges B-Zell-Lymphom
Authors: Schmale Ine
Published: December 2022

Epcoritamab ist ein neuer subkutan zu applizierender bispezifischer Antikörper, der sich in der klinischen Entwicklung befindet. In der EPCORE NHL-1-Studie wird Epcoritamab bei Patienten mit rezidiviertem oder refraktärem großzelligen B-Zell-Lymphom untersucht.
Metastasiertes nicht kleinzelliges Bronchialkarzinom
Authors: Krome Susanne
Published: December 2022

Die gewachsenen Kenntnisse über das genetische Spektrum haben die Behandlung des nicht kleinzelligen Bronchialkarzinoms (NSCLC) revolutioniert. Die Gensequenzierung des Tumorgewebes ist der Schlüssel für die Auswahl der passgenauen, zielgerichteten Therapie. Niederländische Real-World-Daten zeigen, dass auch in der Routineversorgung NGS-basierte (Next Generation Sequencing) zielgerichtete Therapien den nicht-NGS-basierten Therapien überlegen waren. Dabei wurde auch gezeigt, dass 1 von 6 Patienten mit einem NSCLC im Stadium IV noch keinen Test auf EGFR-Mutationen und 1 von 9 mit EGFR-Mutation keine zielgerichtete Therapie erhielten.
Begleitung von Frauen mit BRCA-Varianten
Authors: Krome Susanne
Published: December 2022

Frauen mit Varianten des BRCA-Gens haben ein stark erhöhtes Risiko für Mamma- und Ovarialkarzinome. Das löst häufig große Ängste aus und verschlechtert erheblich die Lebensqualität. Die unter Psychologen umstrittene Methode „The Work“ nach Byron Katie stärkte in einer randomisierten Studie betroffene Frauen und wirkte sich auf alle psychologischen Domänen positiv aus.
Mammakarzinom
Authors: Schmale Ine
Published: December 2022

Den meisten Brustkrebspatientinnen wird nach einer brusterhaltenden Operation eine Bestrahlung des Tumorbetts als Teil der adjuvanten Vorsorge angeboten. In der LUMINA-Studie wurde nun gezeigt, dass Patientinnen mit sehr geringem Progressionsrisiko eine Radiatio erspart werden kann.
Ovarialkarzinom
Authors: Schmale Ine
Published: December 2022

Die Phase-III-Studie ATHENA untersucht in 4 Studienarmen eine optimale Erstlinien-Erhaltungstherapie mit Rucaparib (Rubraca®). Die beim ASCO 2022 präsentierten Ergebnisse der ATHENA-MONO-Arme bestätigen eine Verlängerung des progressionsfreien Überlebens (PFS) mit Rucaparib unabhängig vom HRD-Status (homologe Rekombinations-Defizienz).
Die Schnellschnittdiagnostik von Basalzellkarzinomen – eine Besonderheit der Karlsruher Hautklinik
Authors: Frenzel Ann-Kathrin , Klemke Claus-Detlev , Kemter Jürgen
Published: December 2022

Bei der Operation von Basalzellkarzinomen gibt es an der Karlsruher Hautklinik zwei
unterschiedliche Vorgehensweisen, die sich primär in der Art der mikrografisch kontrollierten
histologischen Aufarbeitung der Tumoren unterscheiden. Die Schnellschnittdiagnostik, die
hautklinikintern durchgeführt wird, kommt bei Basalzellkarzinomen kleiner als 5 cm² zur
Anwendung, ermöglicht ein gewebeschonendes Operieren und erspart Patienten lange Wartezeiten
bis zum Erhalt des histologischen Ergebnisses. Das Verfahren der Schnelleinbettung kommt bei
Basalzellkarzinomen größer als 5 cm² und Tumoren, die zuvor nicht histologisch gesichert
wurden, zur Anwendung. In Zusammenarbeit mit dem Pathologischen Institut werden die
exzidierten Tumoren bis zum Folgetag histologisch aufgearbeitet, sodass am Folgetag eine
gezielte Nachexzision oder ein Wundverschluss erfolgen kann.
Rapid Prototyping and Implementation of Electronic Order Sets for Critically Ill Adults with COVID-19 Admitted to a Children's Hospital
Authors: McKinnon Nicole K. , Silver Shawna , Pong Sandra , Seto Winnie , Chan Phoebe , Gilfoyle Elaine , Jessa Karim , Gray Seth B.
Published: December 2022

Objectives An eight-bed adult coronavirus (COVID-19) critical care (CC) unit was established within our pediatric CC unit (PCCU) when SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) variants increased the CC bed demand. Our objective was to rapidly implement electronic order sets (OSs) to facilitate computerized provider order entry (CPOE) for adult patients admitted within a children's hospital.

Methods OS development began from the assessment of OSs from seven adult CC units. Using a pre-existing PCCU admission template, we created two OSs: adult COVID-19 admission and ongoing care. We tested the prototypes in a multidisciplinary onsite–virtual hybrid tabletop simulation to evaluate usability within established workflows. Participants utilized role-specific profiles within the electronic health record (EHR) training environment which paralleled their computer interface, permitting charting and documentation. EHR analysts were present to gather change requests. Following implementation, we performed twice-daily huddles with end users to identify issues.

Results A total of 13 multidisciplinary bedside providers participated in simulation testing of the prototypes. Two safety issues were addressed before implementation. The electronic OSs were developed, tested, and implemented within 8 days. The postimplementation huddles identified one medication addition, and no deletions were necessary.

Conclusion Caring for adult COVID-19 patients within a freestanding children's hospital presents challenges and has the potential to introduce latent safety threats. Rapid development and implementation of electronic OSs within 8 days to facilitate CPOE and reduce health care provider cognitive burden relied on leveraging functionality within the EMR system, performing iterative testing with a tabletop simulation, integration into previously established workflows, and gathering post-implementation feedback for continuous improvement.
Laparoscopic Intracorporeal Anastomosis
Authors: Goldstone Robert N. , Popowich Daniel A.
Published: December 2022

Given the progression of laparoscopic surgery, questions continue to arise as to the ideal technique for a laparoscopic colectomy. The most debated of these questions is whether it is best to complete an intracorporeal (ICA) or extracorporeal (ECA) intestinal anastomosis. Here, we review the literature to date and report the equivalent safety and efficacy of ICA and ECA for laparoscopic right colectomy. However, these studies also indicate that when completed, ICA may prove beneficial with respect to earlier return of bowel function, less postoperative pain, shorter incision length, and reduced risk of wound infections. For this, we present the tips and tricks for completing all forms of laparoscopic ICAs during laparoscopic colectomy.
Lateral Thoracic Expansion for Jeune's Syndrome, Surgical Approach, and Technical Details
Authors: Lena Federica , Piro Liliana , Forlini Valentina , Guerriero Vittorio , Salvati Pietro , Stagnaro Nicola , Sacco Oliviero , Torre Michele , Mattioli Girolamo
Published: December 2022

Introduction Jeune's syndrome, or asphyxiating thoracic dystrophy (ATD), is a rare autosomal recessive disorder characterized by skeletal dysplasia. Ribs are typically short and horizontal resulting—in lethal variant—in severe lung hypoplasia, progressive respiratory failure, and death. Lateral thoracic expansion (LTE) consists in staggered bilateral ribs osteotomy leading to chest expansion and lung development. Studies on LTE in ATD patients report encouraging data, but the rarity of ATD implies the lack of a standardized surgical path. The aim of this report is to present our experience with LTE, the technical modification we adopted, and patients' clinical outcome.

Materials and Methods We retrospectively reviewed data of 11 LTE performed in 7 ATD patients with lethal variant. Information regarding pre- and postoperative clinical conditions and surgical details was collected. We adopted a single-stage or a two-stage approach based on patient clinical condition. Computed tomography (CT) scan was performed before and after surgery and lung volume was calculated.

Results Five patients are alive, while two died in intensive care unit for other than respiratory cause (sepsis). Most patients experienced clinical improvement in terms of decreased respiratory infections rate, need for ventilation, and improved exercise tolerance. Postoperative CT scan demonstrated a median lung volume increase of 88%.

Conclusion Mortality in ADT patients is high. However, LTE is a feasible and safe surgical approach, which could improve clinical conditions and survival rate. Survived patients showed postoperatively less oxygen requirement and improved clinical conditions.
Thermal effects on the performance of a nanosecond dielectric barrier discharge plasma actuator at low air pressure
Authors: Chen Zongnan , Wong Chung Chu , Wen Chih-Yung
Published: December 2022

The thermal effects of a pulsed nanosecond dielectric barrier discharge plasma actuator (NSDBD) with varying pulse voltages and pulse repetitive frequencies under different air pressures ranging from 0.1 to 1 bar are studied experimentally. By observing discharge features with a charge-coupled device camera, the transition from a filamentary discharge mode to a diffuse mode with decreasing air pressure is described. The filamentary streamers extend along the radius direction, forming a thicker yet more stable and uniform plasma region due to the increasing ionized volume yielded by the decreasing air pressure to maintain the high values of the reduced electric field. The spatiotemporal temperature distribution on the surface is captured by an infrared camera, indicating that the heated surface can be divided into three typical regions with different features. Because gas heating is generated in the quenching process of excited molecules, the maximum temperature increase on the surface occurs in the plasma region and attenuates downstream. The surface temperature increase is primarily caused by heat convection from the residual heat in plasma and the heat generated by the dielectric losses. The results of heat flux on the surface suggest that the rising applied voltage may not increase the heat flux in a moderate air pressure ranging from 0.6 to 0.8 bar. Different discharge modes and discharge parameters exhibit markedly different thermal performances. Also, the Schlieren technique and the pressure sensor are used to visualize the induced shock wave, estimate the thermal expansion region, and measure the overpressure strength. The results of the overpressure strength at different air pressures are similar to the thermal features, which highlights the strong influence of the discharge mode on the thermal effect of NSDBD plasma actuators.
Experiment on jet–vortex interaction for variable mutual spacing
Authors: Bölle Tobias , Brion Vincent , Couliou Marie , Molton Pascal
Published: December 2022

The interaction of a line vortex with a collinearly aligned jet is a prototypical configuration for various important applications in aeronautics. The purpose of this study is to analyze the impact of the jet flow on the kinematics and dynamics of a trailing vortex. A particular emphasis is on the effect of a variable relative jet–vortex spacing. To this end, we realized four different jet–vortex configurations in a wind tunnel experiment at a chord-based Reynolds number of 1.7×105 using high-speed stereo particle image velocimetry measurements in five transversal planes located between 2 and 26 chords behind the wing. Stochastic analyses reveal that the jet generally contributes an external excitation to the vortex as a function of the mutual spacing. Compared with the configuration without jets, the vortex amplification increases upon reducing the jet–vortex spacing. Most notably, for all but the closest spacing, the vortex response is qualitatively the same, changing mainly in magnitude. For the closest spacing, however, the dynamics is considerably different, which we suspect to be a consequence of jet entrainment. Proper orthogonal decomposition reveals, for the first time, that the collinearly aligned jet tends to excite a progressively broader range of vortex modes as the jet–vortex spacing is reduced. A close examination of the vortex mean flow seems to preclude linear vortex instabilities, while the vortex characteristics hint toward some form of receptivity mechanism to disturbances being located in the free stream. Our analyses are useful to validate simulation tools on configurations combining simultaneous lift and thrust effects.
Extension of Galilean invariance to uniform motions for a relativistic equation of fluid flows
Authors: Caltagirone Jean-Paul
Published: December 2022

Galilean invariance and the Lorentz transformation are the two pillars of mechanics that an equation of motion must respect. The objective is to extend the Galilean invariance to uniform rotational motion and to expansion motion of which motion at constant translational velocity is only a special case. The second goal is to show that the discrete equation of motion is naturally relativistic without using the Lorentz transformation. The realization of these two aims leads to different concepts of special relativity: (i) space is homogeneous and isotropic and (ii) time, which flows regularly, is invariant by translation. These invariances, symmetric for translation and rotation, observed by the discrete equation of motion give it fundamental conservation properties to extend the scope of the equations of fluid mechanics to other fields of physics.
Advection-based temporal reconstruction technique for turbulent velocity fields
Authors: Vocke Maegan , Kapulla Ralf , Morton Chris , Klein Markus , Martinuzzi Robert J.
Published: December 2022

The characterization of turbulent flows is challenging due to the interaction of widespread spatiotemporal scales. Experimental techniques such as particle image velocimetry can be used to obtain spatially resolved flow measurements; however, these systems often suffer from limited acquisition rates. The present work investigates the ability of an advection-based flow reconstruction technique to increase the temporal resolution of turbulent flow data without any prior knowledge of the flow physics. A semi-Lagrangian technique is suggested to obtain fluid trajectories through a forward and backward integration of the available spatiotemporal data. The estimates are then fused using a temporal weighting scheme to yield velocity fields at intermediate times. The performance of the method is verified against three-dimensional direct numerical simulation (DNS) data of a plane jet at Re = 10 000. Extracting time series data from the spatially and temporally resolved DNS results, five test cases with artificially lowered sampling frequencies were generated. Spectral analysis revealed that the characteristic frequency found in shear layer-dominated flows can be obtained even for the most extreme case. Additionally, spectral information up to two orders of magnitude beyond the Nyquist criteria is successfully recovered throughout the spatial domain—surpassing the performance of previously introduced methods. The maximum spectral reconstruction error of the suggested method, defined as net energy loss or gain, fell within the bounds of [−5, 3]%, with a corresponding global energy difference in the range of [−2, 1]%. Furthermore, the spatially averaged reconstruction error for the velocity fluctuations was bound by [6±6]%.
Linear attention coupled Fourier neural operator for simulation of three-dimensional turbulence
Authors: Peng Wenhui , Yuan Zelong , Li Zhijie , Wang Jianchun
Published: December 2022

Modeling three-dimensional (3D) turbulence by neural networks is difficult because 3D turbulence is highly nonlinear with high degrees of freedom and the corresponding simulation is memory-intensive. Recently, the attention mechanism has been shown as a promising approach to boost the performance of neural networks on turbulence simulation. However, the standard self-attention mechanism uses O(n2) time and space with respect to input dimension n, and such quadratic complexity has become the main bottleneck for attention to be applied on 3D turbulence simulation. In this work, we resolve this issue with the concept of a linear attention network. The linear attention approximates the standard attention by adding two linear projections, reducing the overall self-attention complexity from O(n2) to O(n) in both time and space. The linear attention coupled Fourier neural operator (LAFNO) is developed for the simulation of 3D isotropic turbulence and free shear turbulence. Numerical simulations show that the linear attention mechanism provides 40% error reduction at the same level of computational cost, and LAFNO can accurately reconstruct a variety of statistics and instantaneous spatial structures of 3D turbulence. The linear attention method would be helpful for the improvement of neural network models of 3D nonlinear problems involving high-dimensional data in other scientific domains.
Bragg scattering of flexural-gravity waves by a series of polynyas in the context of blocking dynamics
Authors: Barman S. C. , Boral S. , Sahoo T.
Published: December 2022

Flexural-gravity wave scattering due to an array of polynyas is investigated from the perspective of the blocking dynamics. The canonical eigenfunction expansion method is generalized to account for multiple propagating wave modes within blocking frequencies. Bragg scattering occurs due to the presence of multiple gaps in the floating ice sheet, and the number of sub-harmonic peaks in wave reflection becomes one/two less than the number of gaps as the reflection coefficient varies with a change in gap/ice-sheet length. In addition, the amplitudes of harmonic peaks in wave reflection increase with an increase in the number of gaps. The variation of wave reflection with an increase in wavenumber/length of the ice sheet depicts that common zero minima occur for an even number of gaps, while common sub-harmonic maxima occur for an odd number of gaps. The scattering coefficients vary between zero and unity within the blocking frequencies, despite the individual amplitudes of the scattered waves becoming more than unity for certain frequencies. Noticeably, higher amplitudes of the scattered waves are associated with lower energy transfer rates and vice versa. Extrema in wave reflection occur for higher values of frequency within the primary and secondary blocking points. In addition, removable discontinuities are found in the scattering coefficient at the blocking frequencies, whereas a jump discontinuity is observed for certain frequencies within the blocking limits due to the incident wave mode conversion. Moreover, irregularities in the ice sheet's deflection are observed for any frequency within the blocking limit due to the superposition of three propagating wave modes.
High-amplitude effect on single-mode Richtmyer–Meshkov instability of a light–heavy interface
Authors: Wang Hui , Wang He , Zhai Zhigang , Luo Xisheng
Published: December 2022

The high-amplitude effect on the Richtmyer–Meshkov instability flow characteristics is investigated by examining the interaction of a planar shock with a single-mode air–SF6 interface both experimentally and numerically. In our experiments, the soap–film technique is adopted to generate well-defined initial interfaces, and the shocked flows are recorded by high-speed schlieren photography. Numerical simulations are performed to highlight the effects of wave patterns on interface movements at the early stage. For cases with high initial amplitudes, a cavity is formed at each spike tip. The cavity formation is ascribed to the vorticity deposition on the slip lines resulting from the Mach reflection of the transmitted shock wave. A series of transverse shocks introduce the secondary compression effect, which changes the interface morphology and causes the failure of the impulsive model in predicting the amplitude linear growth rate. Those modified linear models considering a reduction factor are also found incapable of accurately predicting the linear growth rate. Moreover, a non-monotone dependence of linear growth rate on initial amplitude is observed. Although similar observations were reported in previous numerical simulations, they have never been reported in experiments before. According to the pressure and velocity distributions, the effects of shock–shock interaction on the movements of the interface peak and trough are demonstrated, and the mechanism of non-monotone dependence is discussed. The validity of the existing nonlinear model proposed for predicting the development of a single-mode interface is further tested. It is shown that the applicability of the model worsens as the initial amplitude or dimensionless time increases.
Effect of velocity and radius distribution on jet breakup
Authors: Kang Tianyu , Yu Qingbo , Liu Zhongyuan , Tao Shengkai
Published: December 2022

The focus of this paper is on the effect of velocity and radius distribution on jet breakup. A theoretical model is established to analyze and predict the velocity distribution along the jet, which is physically and mathematically continuous. The simplified forms of the breakup time, the disturbance growth rate, and the disturbance level considering the velocity and radius distribution are presented. A series of prediction methods for predicting the jet breakup length and droplet size are developed. A Newtonian laminar jet falling vertically was experimentally observed to validate the theoretical model and prediction methods. It is shown that the relaxation of the velocity profile leads to the rapid contraction of the jet radius near the outlet, which leads to the increase in the growth rate of the instability disturbance. The surface tension prevents the growth rate of disturbance from increasing by restraining the contraction of jet radius. The final amplification of jet velocity and contraction due to gravity acceleration depend on the Froude number and breakup length. When the influence of jet radius distribution on the growth rate of disturbance is considered, the breakup time is indirectly affected by the breakup length. The experimental and predicted results show that the accelerated falling of jet lengthens the breakup length traveled by the jet in a shortened breakup time due to the contraction of jet radius. The droplet volume is proportional to the predicted jet cross-sectional area at the breakup position and the Rayleigh wavelength determined by the nozzle radius.
Supersonic flow unsteadiness induced by control surface deflections
Authors: Karthick S. K. , Bhelave Dhairyadhar , De Ashoke
Published: December 2022

Control surface deployment in a supersonic flow has many applications, including flow control, mixing, and body-force regulation. The extent of control surface deflections introduces varying flow unsteadiness. The resulting fluid dynamics influence the downstream flow characteristics and fluid–structure interactions significantly. In order to understand the gas dynamics, an axisymmetric cylindrical body with a sharp-tip cone at zero angles of attack (α=0°) is examined in a free stream Mach number of M∞=2.0 and Reynolds number of ReD=2.16×106 (D = 50 mm). Four static control surface deflection angles (θ=π/36,π/6,π/3, and π/2 rad) are considered around the base body. The cases are computationally investigated through a commercial flow solver adopting a two-dimensional detached eddy simulation strategy. Recirculation bubble length, drag coefficient's variation, wall-static pressure statistics, acoustic loading on the model and the surroundings, x − t trajectory and x − f spectral analysis, pressure fluctuation's correlation coefficient on the model, and modal analysis are obtained to understand the flow unsteadiness. At θ=[π/36], the wall-static pressure fluctuations behind the control surface are minimal and periodic, with a mere acoustic load of about 50 dB. At θ=[π/2], a violent periodic fluctuation erupted everywhere around the control surface, leading to a higher acoustic load of about 150 dB (three times higher than the previous). For θ=[π/6] and [π/3], high-frequency fluctuations with small- and large-scale structures continuously shed along the reattaching shear layer, thereby causing a broadened spectra in the control surface wake.
Improved convergence based on two-point Padé approximants: Simple shear, uniaxial elongation, and flow past a sphere
Authors: Housiadas Kostas D.
Published: December 2022

We investigate the performance of two-point Padé approximants on the truncated series solutions for the shear and elongational viscosities (obtained directly from the exact solutions or by asymptotic methods) for viscoelastic flows modeled with the Giesekus constitutive equation. Τhe major dimensionless groups are the Weissenberg number ( Wi), the Giesekus mobility parameter ( α), and the ratio of the polymer viscosity to the total viscosity of the fluid ( ηp) in terms of which the exact analytical solutions for the shear and elongational viscosities are found. The exact solutions are used to derive truncated series expansions in terms of the Weissenberg number at the Newtonian limit (zero Wi) and in terms of the inverse of the Weissenberg number at the purely elastic limit (infinite Wi). These series are then used to construct low- and high-order two-point diagonal Padé approximants. It is found that both the low- and high-order formulas predict the right trends over the entire range of Wi, from the Newtonian limit to the pure elastic limit. As expected, the high-order formula is much more accurate than the low-order formula. The results show that viscoelastic phenomena, such as shear thinning and extensional thickening, at any value of the Weissenberg number can be predicted analytically with acceptable accuracy using the proposed two-point Padé non-linear analysis. Finally, a fourth-order formula in terms of the Weissenberg number (or in terms of the Deborah number) for the drag force on a rigid sphere that translates with constant speed in a Giesekus fluid is also provided along with a discussion regarding the missing information from the literature, that is, required to perform the proposed non-linear analysis.
Post-acute COVID-19 condition (PACC): a perspective on collaborative Australian research imperatives and primary health models of care
Authors: Tippett Emma , Hitch Danielle , Irving Louis , Watters David
Published: December 2022

Post-acute COVID-19 condition (PACC) – also known as long COVID – is a serious and growing problem in primary health. This letter describes the work of the Victorian Post-Acute COVID-19 Study (VPACS) group, which comprises clinician researchers, basic scientists and consumers. Two key priorities for PACC research in Australia are identified and discussed: (1) the establishment of COVID-19 patient registries and data linkage; and (2) the consolidation of clinical guidelines. Collaboration between consumers, researchers, clinicians and institutions must be the foundation of PACC management in Australia. Ongoing research should focus on large, multicentre controlled studies, the protective effect of vaccination, differential impacts from variants, pathobiological underpinnings, disease mechanisms to avoid severe and enduring impacts on the Australian economy. The lived experience of people with PACC is also essential to enable the design and implementation of effective models of care. VPACS brings a diverse group of people together to work on a shared vision of holistic and high-quality care, and collectively maximise their impact on outcomes for patients and the broader community.
Characterization of the surugamide biosynthetic gene cluster of TUA-NKU25, aStreptomyces diastaticusstrain isolated from Kusaya, and its effects on salt-dependent growth
Authors: Takeuchi Aoi , Hirata Asahi , Teshima Aiko , Ueki Miu , Satoh Takumi , Matsuda Kenichi , Wakimoto Toshiyuki , Arakawa Kenji , Ishikawa Morio , Suzuki Toshihiro
Published: December 2022

Kusaya, a traditional Japanese fermented fish product, is known for its high preservability, as it contains natural antibiotics derived from microorganisms, and therefore molds and yeasts do not colonize it easily. In this study, the Streptomyces diastaticus strain TUA-NKU25 was isolated from Kusaya, and its growth as well as the production of antibiotics were investigated. Strain TUA-NKU25 showed advantageous growth characteristics in the presence, but not in the absence, of sodium chloride (NaCl). Antimicrobial assay, high-performance liquid chromatography, and electrospray ionization-mass spectrometry analysis showed that this strain produced surugamide A and uncharacterized antimicrobial compound(s) during growth in the presence of NaCl, suggesting that the biosynthesis of these compounds was upregulated by NaCl. Draft genomic analysis revealed that strain TUA-NKU25 possesses a surugamide biosynthetic gene cluster (sur BGC), although it is incomplete, lacking surB/surC. Phylogenetic analysis of strain TUA-NKU25 and surugamide-producing Streptomyces showed that sur BGC formed a clade distinct from other known groups.
Large-scale screening of yeast strains that can utilize proline
Authors: Tanahashi Ryoya , Nishimura Akira , Nguyen Minh , Sitepu Irnayuli , Fox Glen , Boundy-Mills Kyria , Takagi Hiroshi
Published: December 2022

Proline contributes to the taste and flavor of foods. The yeast Saccharomyces cerevisiae poorly assimilates proline during fermentation processes, resulting in the accumulation of proline in fermentative products. We performed here a screening of in total 1138 yeasts to obtain strains that better utilize proline. Our results suggest that proline utilization occurs in the genera of Zygoascus, Galactomyces, and Magnusiomyces.
Inpactor2: a software based on deep learning to identify and classify LTR-retrotransposons in plant genomes
Authors: Orozco-Arias Simon , Humberto Lopez-Murillo Luis , Candamil-Cortés Mariana S , Arias Maradey , Jaimes Paula A , Rossi Paschoal Alexandre , Tabares-Soto Reinel , Isaza Gustavo , Guyot Romain
Published: December 2022

LTR-retrotransposons are the most abundant repeat sequences in plant genomes and play an important role in evolution and biodiversity. Their characterization is of great importance to understand their dynamics. However, the identification and classification of these elements remains a challenge today. Moreover, current software can be relatively slow (from hours to days), sometimes involve a lot of manual work and do not reach satisfactory levels in terms of precision and sensitivity. Here we present Inpactor2, an accurate and fast application that creates LTR-retrotransposon reference libraries in a very short time. Inpactor2 takes an assembled genome as input and follows a hybrid approach (deep learning and structure-based) to detect elements, filter partial sequences and finally classify intact sequences into superfamilies and, as very few tools do, into lineages. This tool takes advantage of multi-core and GPU architectures to decrease execution times. Using the rice genome, Inpactor2 showed a run time of 5 minutes (faster than other tools) and has the best accuracy and F1-Score of the tools tested here, also having the second best accuracy and specificity only surpassed by EDTA, but achieving 28% higher sensitivity. For large genomes, Inpactor2 is up to seven times faster than other available bioinformatics tools.
A review of methods for predicting DNA N6-methyladenine sites
Authors: Han Ke , Wang Jianchun , Wang Yu , Zhang Lei , Yu Mengyao , Xie Fang , Zheng Dequan , Xu Yaoqun , Ding Yijie , Wan Jie
Published: December 2022

Deoxyribonucleic acid(DNA) N6-methyladenine plays a vital role in various biological processes, and the accurate identification of its site can provide a more comprehensive understanding of its biological effects. There are several methods for 6mA site prediction. With the continuous development of technology, traditional techniques with the high costs and low efficiencies are gradually being replaced by computer methods. Computer methods that are widely used can be divided into two categories: traditional machine learning and deep learning methods. We first list some existing experimental methods for predicting the 6mA site, then analyze the general process from sequence input to results in computer methods and review existing model architectures. Finally, the results were summarized and compared to facilitate subsequent researchers in choosing the most suitable method for their work.
Multimodal data fusion based on IGERNNC algorithm for detecting pathogenic brain regions and genes in Alzheimer’s disease
Authors: Wang Shuaiqun , Zheng Kai , Kong Wei , Huang Ruiwen , Liu Lulu , Wen Gen , Yu Yaling
Published: December 2022

At present, the study on the pathogenesis of Alzheimer’s disease (AD) by multimodal data fusion analysis has been attracted wide attention. It often has the problems of small sample size and high dimension with the multimodal medical data. In view of the characteristics of multimodal medical data, the existing genetic evolution random neural network cluster (GERNNC) model combine genetic evolution algorithm and neural network for the classification of AD patients and the extraction of pathogenic factors. However, the model does not take into account the non-linear relationship between brain regions and genes and the problem that the genetic evolution algorithm can fall into local optimal solutions, which leads to the overall performance of the model is not satisfactory. In order to solve the above two problems, this paper made some improvements on the construction of fusion features and genetic evolution algorithm in GERNNC model, and proposed an improved genetic evolution random neural network cluster (IGERNNC) model. The IGERNNC model uses mutual information correlation analysis method to combine resting-state functional magnetic resonance imaging data with single nucleotide polymorphism data for the construction of fusion features. Based on the traditional genetic evolution algorithm, elite retention strategy and large variation genetic algorithm are added to avoid the model falling into the local optimal solution. Through multiple independent experimental comparisons, the IGERNNC model can more effectively identify AD patients and extract relevant pathogenic factors, which is expected to become an effective tool in the field of AD research.
A fully differentiable ligand pose optimization framework guided by deep learning and a traditional scoring function
Authors: Wang Zechen , Zheng Liangzhen , Wang Sheng , Lin Mingzhi , Wang Zhihao , Kong Adams Wai-Kin , Mu Yuguang , Wei Yanjie , Li Weifeng
Published: December 2022

The recently reported machine learning- or deep learning-based scoring functions (SFs) have shown exciting performance in predicting protein–ligand binding affinities with fruitful application prospects. However, the differentiation between highly similar ligand conformations, including the native binding pose (the global energy minimum state), remains challenging that could greatly enhance the docking. In this work, we propose a fully differentiable, end-to-end framework for ligand pose optimization based on a hybrid SF called DeepRMSD+Vina combined with a multi-layer perceptron (DeepRMSD) and the traditional AutoDock Vina SF. The DeepRMSD+Vina, which combines (1) the root mean square deviation (RMSD) of the docking pose with respect to the native pose and (2) the AutoDock Vina score, is fully differentiable; thus is capable of optimizing the ligand binding pose to the energy-lowest conformation. Evaluated by the CASF-2016 docking power dataset, the DeepRMSD+Vina reaches a success rate of 94.4%, which outperforms most reported SFs to date. We evaluated the ligand conformation optimization framework in practical molecular docking scenarios (redocking and cross-docking tasks), revealing the high potentialities of this framework in drug design and discovery. Structural analysis shows that this framework has the ability to identify key physical interactions in protein–ligand binding, such as hydrogen-bonding. Our work provides a paradigm for optimizing ligand conformations based on deep learning algorithms. The DeepRMSD+Vina model and the optimization framework are available at GitHub repository https://github.com/zchwang/DeepRMSD-Vina_Optimization.
MARPPI: boosting prediction of protein–protein interactions with multi-scale architecture residual network
Authors: Li Xue , Han Peifu , Chen Wenqi , Gao Changnan , Wang Shuang , Song Tao , Niu Muyuan , Rodriguez-Patón Alfonso
Published: December 2022

Protein–protein interactions (PPIs) are a major component of the cellular biochemical reaction network. Rich sequence information and machine learning techniques reduce the dependence of exploring PPIs on wet experiments, which are costly and time-consuming. This paper proposes a PPI prediction model, multi-scale architecture residual network for PPIs (MARPPI), based on dual-channel and multi-feature. Multi-feature leverages Res2vec to obtain the association information between residues, and utilizes pseudo amino acid composition, autocorrelation descriptors and multivariate mutual information to achieve the amino acid composition and order information, physicochemical properties and information entropy, respectively. Dual channel utilizes multi-scale architecture improved ResNet network which extracts protein sequence features to reduce protein feature loss. Compared with other advanced methods, MARPPI achieves 96.03%, 99.01% and 91.80% accuracy in the intraspecific datasets of Saccharomyces cerevisiae, Human and Helicobacter pylori, respectively. The accuracy on the two interspecific datasets of Human-Bacillus anthracis and Human-Yersinia pestis is 97.29%, and 95.30%, respectively. In addition, results on specific datasets of disease (neurodegenerative and metabolic disorders) demonstrate the ability to detect hidden interactions. To better illustrate the performance of MARPPI, evaluations on independent datasets and PPIs network suggest that MARPPI can be used to predict cross-species interactions. The above shows that MARPPI can be regarded as a concise, efficient and accurate tool for PPI datasets.