bluuebunny/crossref_metadata_2025 huggingface dataset:
Research progress in insulating and thermal conductivity of fluorinated graphene and its polyimide composites
Authors: Wang Xin , Liu Shuyan , Han Haoyu , Liu Xiangyang , Wang Xu
Published: December 2023

The demand for innovative thermal management materials with superior thermal conductivity and electrical insulating properties has significantly increased with the development of portable and flexible electronic gadgets. Fluorinated graphene (FG) has recently attracted the attention of the scientific community because of its exceptional thermal conductivity and electrical insulating qualities. This work aims to provide a detailed analysis of the structure‐property relationships inherent in FG, including both chemical and physical properties, and to explain the FG manufacturing process. Special attention should be paid to a thorough analysis of the thermodynamic conduction mechanism exhibited by FG, including the effects of corrugation size, fluorine coverage, and fluorine atom distribution on its thermal conductivity. The essay also examines in‐depth the most current and cutting‐edge developments addressing the utilisation of FG as a functional filler in composite‐modified polyimide (PI) materials. Furthermore, it has been noted as a crucial component in answering the needs for possible applications by maximising thermal conductivity and mechanical qualities in FG/PI composites through particular FG structural engineering and increased FG‐PI interaction. As a result, these elements serve as the main focus of ongoing research projects, highlighting important directions for development and investigation.
The cosmological analysis of X-ray cluster surveys
Authors: Cerardi N. , Pierre M. , Valageas P. , Garrel C. , Pacaud F.
Published: December 2023

Context. Cosmological studies have now entered Stage IV according to the Dark Energy Task Force (DETF) prescription. New missions (Euclid, Rubin Observatory, SRG/eROSITA) will cover very large fractions of the sky with unprecedented depth. These are expected to provide the required ultimate accuracy in the dark energy (DE) equation of state (EoS), which is required for the elucidation of the origin of the acceleration of cosmic expansion. However, none of these projects have the power to systematically unveil the galaxy cluster population in the 1 < z < 2 range. There therefore remains the need for an Athena-like mission to run independent cosmological investigations and scrutinise the consistency between the results from the 0 < z < 1 and 1 < z < 2 epochs.

Aims. We study the constraints on the DE EoS and on primordial non-gaussanities for typical X-ray cluster surveys executed by a generic Athena-like Wide Field Imager. We focus on the impact of cluster number counts in the 1 < z < 2 range.

Methods. We consider two survey designs: 50 deg2 at 80 ks (survey A) and 200 deg2 at 20 ks (survey B). We analytically derive cluster number counts and predict the cosmological potential of the corresponding samples, A and B, by means of a Fisher analysis. We adopt an approach that forward models the observed properties of the cluster population in the redshift–count rate–hardness ratio parameter space.

Results. The achieved depth allows us to unveil the halo mass function down to the group scale out to z = 2. We predict the detection of thousands of clusters down to a few 1013h−1 M⊙, in particular 940 and 1400 clusters for surveys A and B, respectively, at z > 1. Such samples will allow a detailed modelling of the evolution of cluster physics along with a standalone cosmological analysis. Our results suggest that survey B has the optimal design as it provides greater statistics. Remarkably, high-redshift clusters represent 15% or less of the full samples but contribute at a much higher level to the cosmological accuracy: by alleviating various degeneracies, these objects allow a significant reduction of the uncertainty on the cosmological parameters: Δwa is reduced by a factor of ∼2.3 and
Δ fNLloc
by a factor of ∼3.

Conclusions. Inventorying the deep high-z X-ray cluster population can play a crucial role in ensuring overall cosmological consistency. This will be the major aim of future new-generation Athena-like missions.
Reconstruction of manifold embeddings into Euclidean spaces via intrinsic distances
Authors: Puchkin Nikita , Spokoiny Vladimir , Stepanov Eugene , Trevisan Dario
Published: December 2023

We consider the problem of reconstructing an embedding of a compact connected Riemannian manifold in a Euclidean space up to an almost isometry, given the information on intrinsic distances between points from its “sufficiently large” subset. This is one of the classical manifold learning problems. It happens that the most popular methods to deal with such a problem, with a long history in data science, namely, the classical Multidimensional scaling (MDS) and the Maximum variance unfolding (MVU), actually miss the point and may provide results very far from an isometry; moreover, they may even give no bi-Lipshitz embedding. We will provide an easy variational formulation of this problem, which leads to an algorithm always providing an almost isometric embedding with the distortion of original distances as small as desired (the parameter regulating the upper bound for the desired distortion is an input parameter of this algorithm).
Bewegungsförderung durch Bewegungscoaches in der
Adipositas-Selbsthilfe – eine Pilotstudie
Authors: Joisten Christine , Schmidt Lisa
Published: December 2023

Die Rolle der körperlichen Aktivität in der Prävention
und vor allem in der Therapie der Adipositas ist heutzutage unbestritten.
Allerdings sind die Möglichkeiten auf vielen Ebenen begrenzt: u.a.
aufgrund persönlicher Barrieren und Hindernisse, wie
Schamgefühl, erfahrene Stigmatisierung, aber auch aufgrund mangelnder
adäquater Angebote. Eine niederschwellige Möglichkeit stellt die
Qualifizierung von Selbsthilfegruppen (SHG)-Leitungen zu Bewegungscoaches dar,
um durch aktive Pausen und Übungen im Rahmen der Selbsthilfegruppen
Teilnehmende zu mehr Bewegung zu motivieren. Zu diesem Zweck wurden in dieser
Pilotuntersuchung 14 SHG-Leitungen qualifiziert und die Machbarkeit und
Umsetzung im mixed-methods Design geprüft. Auf Basis von 11
Fragebögen von 13 Teilnehmenden zeigte sich, dass die Inhalte insgesamt
sehr positiv aufgenommen wurden, vor allem die bewegungspraktischen Einheiten.
Kombiniert mit dem Lerneffekt, dass auch kleine Bewegungseinheiten
förderlich für die Gesundheit sind, setzten anschließend
73% durchschnittlich 1,4±0,5 Bewegungseinheiten mit
12,9±7,3 SHG-Teilnehmenden während der Gruppentreffen um. 7 von
11 beschrieben eine insgesamt positive Resonanz ihrer Gruppen trotz
früherer Negativ-Erfahrungen. Eine SHG-Leitung beurteilte die
Durchführung als negativ, 4 machten keine Angabe. Unter
Berücksichtigung des Pilotcharakters zeigt sich hier ein erfolgreicher
niederschwelliger Ansatz der Bewegungsförderung; inwiefern
tatsächlich klinisch relevante Effekte bei SHG-Teilnehmenden
nachgewiesen werden können, muss in weiteren randomisiert-kontrollierten
Studien nun geprüft werden.
Ein Gewichtsreduktionskurs mit dem Schwerpunkt der Stärkung
von „Coping“ Strategien für die low carb
Ernährung ist einfach und erfolgreich
Authors: Lilienfeld-Toal Anna. v. , Tews Dietrich , Lilienfeld-Toal Hermann v.
Published: December 2023

Ein Weg zur Reduzierung des Körpergewichts besteht in der Reduktion der
Aufnahme von Kohlenhydraten mit der Nahrung, sodass geringere postprandiale
Anstiege von Blutglukose und Insulin auftreten. Allerdings führt die
Senkung der Blutglukose zu starken Impulsen in der Regulation der
Nahrungsaufnahme. So werden verschiedene Essimpulse bei Menschen mit
Übergewicht ausgelöst, die Kohlenhydrate in der Nahrung
vermeiden. Wir stellten diese Impulse zusammen und entwickelten ein
systematisches Vorgehen, um ihnen zu begegnen. Hiermit bildeten wir ein
Curriculum für einen 1-Jahres-Kurs mit Übergewichtigen, die sich
eine Gewichtsreduktion vornahmen. Die Gruppensitzungen wurden von einer
geschulten Person geleitet. Im Curriculum war zusätzlich ein Austausch
über die Erlebnisse während der Kohlenhydrat-Reduktion
enthalten, sowie die Vermittlung von Wissen über die Pathomechanismen
der Gewichtsentwicklung. Weitere Anforderungen an die Teilnehmer wurden nicht
gestellt. Am Ende des einjährigen Kurses reduzierten 18 Teilnehmer aus
mehreren Gruppen ihr Gewicht im Mittel um 8,6% vom Ausgangsgewicht.
Parameter des Glukosestoffwechsels besserten sich ebenso wie psychologische
Indikatoren für Essimpulse. Wir nehmen an, dass ein solcher Kurs in
Gruppen, der sich auf die psychologischen Gefahren konzentriert, die mit einem
Vermeiden von Kohlenhydraten in der Nahrung verbunden sind, ein einfach
anwendbarer Weg gegen das Problem des Übergewichtes in jeder
spezialisierten Einrichtung ist.
Magenballonimplantation – eine Bestandsaufnahme unter
Berücksichtigung eigener Erfahrungen
Authors: Keßler Rebecca , Glitsch Anne , Hübner Björn , Gärtner Simone , Steveling Antje , Patrzyk Maciej , Keßler Wolfram
Published: December 2023

Die Magenballontherapie wird aktuell konträr diskutiert. Dennoch stellt
dieses Verfahren aus unserer Sicht ein bewährtes und
verhältnismäßig sicheres Hilfsmittel zur kontrollierten
Gewichtsreduktion dar. Die hier nachgewiesene Reduktion aller
Körperfettkompartimente und die signifikante Reduktion des Lebervolumens
ist ein Ergebnis, welches weitere Forschungsansätze eröffnet und
in der Folge ggf. auch eine (positive) Neubewertung des Magenballons im Rahmen
der Adipositas-Therapie erfordert. So ist über das Verhalten von
Gasblasen in Magenballons bisher wenig bekannt. Bei der zukünftigen
Forschung sollte jedoch sehr viel Wert auf eine korrekte Indikationsstellung
(Ziel der Magenballontherapie) und Durchführung der Implantation gelegt
werden.
Through-the-scope clip retention rates and performance in a porcine model
Authors: AbiMansour Jad , Kamba Shunsuke , Wong Kee Song Louis-Michel , Rajan Elizabeth
Published: December 2023

Background and study aims Limited comparative data exist to guide optimal through-the-scope (TTS) clip selection. The aim of this study was to compare the efficacy, retention, and safety of three industry-leading TTS clips on tissue that mimics common clinical scenarios.

Methods A survival study involving six domestic pigs was undertaken. Three commonly used clip models were selected: Assurance (STERIS, Mentor, Ohio, United States), Resolution (Boston Scientific, Boston, Massachusetts, United States), and SureClip (Micro-Tech, Ann Arbor, Michigan, United States). To mimic clinical practice, the following scenarios were assessed: (1) normal mucosa; (2) cold snare resection; and (3) hot mucosal resection simulating fibrotic ulcers. Deployment of clips was randomized to target sites. Repeat endoscopy was performed 2 weeks following placement. Endoscopists rated the ease of use of clip placement on a Likert scale of 1 to 5.

Results Fifty-four clips (18 Assurance, 18 Resolution, and 18 SureClip) were placed in six pigs. Mucosal healing was noted at all sites on follow up. Overall retention was nine of 18 (50.0%) SureClip, 10 of 18 (55.6%) Assurance, and 13 of 18 (72.2%) Resolution (P=0.369). There was no difference in clip retention on normal and cold snare resection sites; however, clip retention was significantly higher for Resolution clips on fibrotic ulcers (50.0% versus 0% for Assurance and 0% SureClip, P=0.03). No adverse events were reported. Ease of use was equivalent across all models.

Conclusions All clips were equivalent in efficacy and safety with successful clip deployment and mucosal healing. Overall retention rate was low for fibrotic tissue, with an improved retention rate observed with Resolution clips.
Efficacy of Cranial Orthosis for Plagiocephaly Based on 2D and 3D Evaluation
Authors: Kajita Hiroki , Tanaka Ichiro , Komuro Hiroaki , Nishimaki Shigeru , Kusakawa Isao , Sakamoto Koichiro
Published: December 2023

Background With the advent of cranial orthoses as therapeutic medical devices for the treatment of severe positional head deformities in Japan, an increasing number of patients are being treated with them. However, assessing the effectiveness of a treatment is often difficult due to the use of different metrics. This study aimed to evaluate the effectiveness of cranial orthoses for deformational plagiocephaly using two- (2D) and three-dimensional (3D) evaluation metrics.

Methods We conducted a retrospective study of infant patients with deformational plagiocephaly who underwent cranial orthosis treatment. We evaluated the severity of deformational plagiocephaly using cranial asymmetry (CA) and the cranial vault asymmetry index (CVAI) as 2D metrics, and anterior and posterior symmetry ratios as 3D metrics. The patients were divided into 24 subgroups based on the initial severity of each outcome and their age at the start of treatment. We analyzed the changes in outcomes and correlations within improvements across the age and severity categories.

Results Overall, 1,038 infants were included in this study. The mean CA, CVAI, and anterior and posterior symmetry ratios improved significantly after cranial orthosis treatment. The improvement in each score was greater in patients with more severe initial deformities and in those who underwent treatment at a younger age.

Conclusion Cranial orthosis treatment was effective in correcting deformational plagiocephaly in infants, as demonstrated by improvements in both 2D and 3D metrics. Patients with more severe initial deformities and those who underwent treatment at a younger age showed greater improvement.
Organocatalytic Approach to the Enantioselective Total Synthesis of (+)-Serinolamides A and B and (+)-Lacosamide
Authors: Waghmode Suresh B. , Jadhao Amardeep R.
Published: December 2023

A short and highly efficient enantioselective synthesis of (+)-serinolamide A, B and (+)-lacosamide from 3-methoxypropanal using l-proline-catalyzed α-amination, Grubbs metathesis, and acid-amine coupling as key steps is reported.
FDG PET-CT in Clinical Management of a Rare Case of Primary Hepatic Lymphoma: Role and Challenges
Authors: Jain Tarun Kumar , Gupta Naveen , Malhotra Hemant , Sharma Lalit Mohan
Published: December 2023

The common differential diagnoses for multiple space-occupying hepatic lesions (SOL) are metastases, multifocal hepatocellular carcinoma, and abscess. Primary hepatic lymphomas are rare entities that present many challenges with regard to their management. Fluorodeoxyglucose positron emission tomography-computed tomography is extensively used for the staging and response assessment of lymphomas but it can be challenging and difficult to interpret in cases with isolated liver involvement. We hereby present the case of an 82-year-old lady who presented with multiple liver SOL.
Correlation between Vertebral Marrow Fat Fraction in MRI Using DIXON Technique and BMD in DXA in Patients of Suspected Osteoporosis
Authors: Naik Suprava , Jain Mantu , Bhoi Sanjeev Kumar , Tripathy Sujit
Published: December 2023

Aim Osteoporosis is a common metabolic bone disease accounting for low back pain (LBP). It is diagnosed by dual-energy X-ray absorptiometry (DXA). Magnetic resonance imaging (MRI), a routine investigation for LBP, is also sensitive to detect fat fraction (FF) of the vertebral body that increases with increasing age. This study aimed to correlate vertebral marrow FF using MRI and bone mineral density (BMD).

Material and Methods Patients presenting with low backache and suspected osteoporosis were included. All patients underwent an MRI of lumbosacral spine and DXA. Patients were categorized into an osteoporotic and a nonosteoporotic group based on the T-score obtained from DXA. “T-scores” of < –2.5 on BMD were considered as osteoporotic spine. T-score of > –2.5 was considered as nonosteoporotic. The FF obtained from the DIXON sequence of MRI was correlated between the two groups.

Result Thirty-one patients were included with a mean age of 54.26 ± 11.6 years. Sixteen patients were osteoporotic based on the defined criteria in the methods. The mean vertebral marrow FF was significantly higher in the osteoporotic patients (64.98 ± 8.8%) compared with the nonosteoporotic (45.18 ± 13.2%) (p = 0.001). The mean FF of the vertebra having fracture (69.19 ± 7.73%) was significantly higher than that of patients without fracture (57.96 ± 5.75%) (p = 0.03). Taking a cutoff value of vertebral marrow FF of 54.85, the sensitivity and specificity of diagnosing osteoporosis were 93 and 80%, respectively, with a confidence interval of 95%. The area under the curve was 0.925.

Conclusion Increased vertebral marrow FF is noted in the osteoporotic spine. FF has an inverse correlation with the T-score obtained from BMD. MRI with FF measurement can provide indirect evidence of osteoporosis, which can be done under one roof, especially in young patients where we need to avoid ionizing radiation.
Algorithmic predictions and pre-emptive violence: artificial intelligence and the future of unmanned aerial systems
Authors: Downey Anthony
Published: December 2023

The military rationale of a pre-emptive strike is predicated upon the calculation and anticipation of threat. The underlying principle of anticipation, or prediction, is foundational to the operative logic of AI. The deployment of predictive, algorithmically driven systems in unmanned aerial systems (UAS) would therefore appear to be all but inevitable. However, the fatal interlocking of martial paradigms of pre-emption and models of predictive analysis needs to be questioned insofar as the irreparable decisiveness of a pre-emptive military strike is often at odds with the probabilistic predictions of AI. The pursuit of a human right to protect communities from aerial threats needs to therefore consider the degree to which algorithmic auguries—often erroneous but nevertheless evident in the prophetic mechanisms that power autonomous aerial apparatuses—essentially authorise and further galvanise the long-standing martial strategy of pre-emption. In the context of unmanned aerial systems, this essay will outline how AI actualises and summons forth “threats” through (i) the propositional logic of algorithms (their inclination to yield actionable directives); (ii) the systematic training of neural networks (through habitually biased methods of data-labelling); and (iii) a systemic reliance on models of statistical analysis in the structural design of machine learning (which can and do produce so-called “hallucinations”). Through defining the deterministic intentionality, systematic biases and systemic dysfunction of algorithms, I will identify how individuals and communities—configured upon and erroneously flagged through the machinations of so-called “black box” instruments—are invariably exposed to the uncertainty (or brute certainty) of imminent death based on algorithmic projections of “threat”.
SEM2: Introducing mechanics in cell and tissue modeling using coarse-grained homogeneous particle dynamics
Authors: Chattaraj Sandipan , Torre Michele , Kalcher Constanze , Stukowski Alexander , Morganti Simone , Reali Alessandro , Pasqualini Francesco Silvio
Published: December 2023

Modeling multiscale mechanics in shape-shifting engineered tissues, such as organoids and organs-on-chip, is both important and challenging. In fact, it is difficult to model relevant tissue-level large non-linear deformations mediated by discrete cell-level behaviors, such as migration and proliferation. One approach to solve this problem is subcellular element modeling (SEM), where ensembles of coarse-grained particles interacting via empirically defined potentials are used to model individual cells while preserving cell rheology. However, an explicit treatment of multiscale mechanics in SEM was missing. Here, we incorporated analyses and visualizations of particle level stress and strain in the open-source software SEM++ to create a new framework that we call subcellular element modeling and mechanics or SEM2. To demonstrate SEM2, we provide a detailed mechanics treatment of classical SEM simulations including single-cell creep, migration, and proliferation. We also introduce an additional force to control nuclear positioning during migration and proliferation. Finally, we show how SEM2 can be used to model proliferation in engineered cell culture platforms such as organoids and organs-on-chip. For every scenario, we present the analysis of cell emergent behaviors as offered by SEM++ and examples of stress or strain distributions that are possible with SEM2. Throughout the study, we only used first-principles literature values or parametric studies, so we left to the Discussion a qualitative comparison of our insights with recently published results. The code for SEM2 is available on GitHub at https://github.com/Synthetic-Physiology-Lab/sem2.
Optimization of double-wire X-pinch using prepulse current
Authors: Jiang Zhiyuan , Wu Jian , Wang Wei , Chen Ziwei , Wang Zhenyu , Lu Yuanbo , Zhao Yiming , Shi Huantong
Published: December 2023

The radiation properties including size, intensity, and pulse width of the double-wire X-pinch were optimized using prepulse current. The optimization mechanism was investigated using optical diagnostics. The X-pinch driven by a current with a peak intensity of ∼250 kA and a rise rate of 0.95 kA/ns was difficult to produce strong radiation. The application of prepulse effectively enhances the current rise rate and intensity of the radiation source. The radiation source also exhibited reduced spatial dimensions and radiation duration, thereby improving spatial and temporal resolution while used in x-ray projection shadow radiography. The magnetic field and current distribution were measured using Faraday rotation. During the early stage, the current predominantly flows in the corona plasma at a larger radius generated by the prepulse current, consequently reducing the load inductance. As the time delay between the main and prepulse current increased, the intensity of the radiation source further increased. This study provides an approach for controlling radiation sources and enables different applications of X-pinches with adjustable prepulse current.
Pinch-off dynamics in unequal-size droplets head-on collision on a wetting surface: Experiments and direct numerical simulations
Authors: Ray Saroj , Han Yu , Cheng Song
Published: December 2023

There is a growing interest in the optimization of spray systems to minimize reflexive separation and enhance droplet coalescence, which has the potential to greatly benefit industrial and agricultural applications. In this investigation, the pinch-off dynamics in head-on impacts of unequal-size droplets on a hydrophobic surface are explored, employing both experimental and numerical approaches. The study focuses on size ratios ranging from 1.0 to 5.0 and impact Weber numbers up to 208. The captured images from the high-speed camera are meticulously processed and analyzed in a detailed manner. Two distinct scenarios are observed in the experimental findings: (1) reflexive separation occurring without the formation of satellite droplets and (2) reflexive separation characterized by the presence of satellite droplets. Direct numerical simulations are also conducted to probe the underlying dynamics during droplet impact. The direct numerical simulation results closely replicate the experimental results, demonstrating excellent agreement with the dynamics of the pinch-off process. The simulated velocity field demonstrates the liquid's movement away from the neck region, leading to progressive thinning and eventual pinch-off. Furthermore, the study examines the evolution of the neck radius over time (τ), revealing a linear variation in log–log plots. Remarkably, the neck radius scales with τ2/3, even for different size ratios. A regime diagram in We–Δ space is reported.
Unintended gas breakdowns in narrow gaps of advanced plasma sources for semiconductor fabrication industry
Authors: Son Sung Hyun , Go Geunwoo , Villafana Willca , Kaganovich Igor D , Khrabrov Alexander , Lee Hyo-Chang , Chung Kyoung-Jae , Chae Gwang-Seok , Shim Seungbo , Na Donghyeon , Kim June Young
Published: December 2023

Occurrence of unintended gas breakdown in the narrow gaps of plasma processing chambers is one of the critical challenges in developing advanced plasma sources. We present a combined experimental and theoretical study of unintended discharges in the narrow gaps of plasma processing chambers and report significant drop of the gas breakdown voltage in the presence of a background plasma facing the gap. Experimentally measured breakdown voltages decrease in subsequent breakdown events due to wall erosion caused by the discharge. Therefore, preventing and mitigating the first discharge is of paramount importance. An analysis of kinetic simulation results indicates that the charged particle influx from the background plasma in the processing chamber into the gap is responsible for the onset of early breakdown: higher charged particle density within the gap modifies the electric field profile, allowing unintended breakdowns to occur at a significantly reduced threshold voltage.
Coupled cluster cavity Born–Oppenheimer approximation for electronic strong coupling
Authors: Angelico Sara , Haugland Tor S. , Ronca Enrico , Koch Henrik
Published: December 2023

Chemical and photochemical reactivity, as well as supramolecular organization and several other molecular properties, can be modified by strong interactions between light and matter. Theoretical studies of these phenomena require the separation of the Schrödinger equation into different degrees of freedom as in the Born–Oppenheimer approximation. In this paper, we analyze the electron–photon Hamiltonian within the cavity Born–Oppenheimer approximation (CBOA), where the electronic problem is solved for fixed nuclear positions and photonic parameters. In particular, we focus on intermolecular interactions in representative dimer complexes. The CBOA potential energy surfaces are compared with those obtained using a polaritonic approach, where the photonic and electronic degrees of freedom are treated at the same level. This allows us to assess the role of electron–photon correlation and the accuracy of CBOA.
Enhanced current-induced magnetization switching via antiferromagnetic coupled interface in Co/Ho heterostructures
Authors: Li S. M. , Poh H. Y. , Jin T. L. , Tan F. N. , Wu S. , Shen K. M. , Jiang Y. F. , Lew W. S.
Published: December 2023

Rare-earth ferromagnetic (RE–FM) heterostructures have attracted significant attention due to their intricate spin structures and physical phenomena. The antiferromagnetic coupled (AFC) interface formed by the distinctive interaction between the FM and RE elements has critical contributions to the magnetization reversal process. In this work, we investigate the enhancement of current-induced magnetization switching with the AFC interface at the Co/Ho heterostructure. The results shows that an increased spin–orbit torque (SOT) efficiency of up to 250% was achieved at a Ho thickness of 7 nm, with a critical switching current density of 2.7 × 1010 A/m2. When a Cu interlayer was introduced between the Co/Ho interface, a decreased SOT efficiency was observed, indicating that the SOT enhancement is primarily attributed to the AFC interfacial effect. At the AFC interface, the interaction between Co and Ho atoms generates an additional torque, enhancing the effective SOT efficiency.
Efficient two-dimensional simulation of primary reference fuel ignition under engine-relevant thermal stratification
Authors: Shahanaghi A. , Karimkashi S. , Kaario O. , Vuorinen V.
Published: December 2023

Despite vast research on engine knock, there remains a limited understanding of the interaction between reaction front propagation, pressure oscillations, and fuel chemistry. To explore this through computational fluid dynamics, the adoption of advanced numerical methods is necessary. In this context, the current study introduces ARCFoam, a computational framework that combines dynamic mesh balancing, chemistry balancing, and adaptive mesh refinement with an explicit, density-based solver designed for simulating high-speed flows in OpenFOAM. First, the validity and performance of the solver are assessed by simulating directly initiated detonation in a hydrogen/air mixture. Second, the study explores the one/two-dimensional (1D/2D) hotspot ignition for the primary reference fuel and illuminates the impact of transitioning to 2D simulations on the predicted combustion modes. The 2D hotspot simulations reveal a variety of 2D physical phenomena, including the appearance of converging shock/detonation fronts as a result of negative temperature coefficient (NTC) behavior and shock wave reflection-induced detonation. The main results of the paper are as follows: (1) NTC chemistry is capable of drastically changing the anticipated reaction front propagation mode by manipulating the local/global reactivity distribution inside and outside the hotspot, (2) subsonic hotspot ignition can induce detonation (superknock) through the generation of shock waves and subsequent wall reflections, and (3) while the 1D framework predicts the initial combustion mode within the hotspot, significant differences between 1D and 2D results may emerge in scenarios involving ignition-to-detonation transitions and curvature effect on shock/detonation front propagation.
Trailing edge actuation for a bluff body at moderate yaw optimized with a genetic algorithm
Authors: Qiao Z. X. , Minelli G. , Noack B. R. , Krajnović S. , Chernoray V.
Published: December 2023

This experimental work is conducted to manipulate the wake to reduce aerodynamic drag using the actuations on the trailing edges of a bluff body at a yaw angle of 10°. Two loudspeakers are separately installed into the vertical trailing edges of the vertical base, creating a zero-net mass-flux jet through vertical slots. A maximum drag reduction of 2% and 1.5% is produced by the single actuation on the windward and leeward side, respectively. When the genetic algorithm is introduced to optimize the actuations on both sides, a drag reduction of 7% is obtained. Thus, the energy efficiency of the entire control system is greatly improved by 80% compared to the best single actuation. The underlying flow mechanism behind the effective parameters is proposed according to the analyses of the drag spectra and the hot-wire data measured with and without control. The genetic algorithm provides a promising optimization strategy for the better control performance of trailing edge actuation on a yawed bluff body. Furthermore, this strategy may have the engineering potential to reduce the drag of ground transport vehicles for a large range of operating conditions. Therefore, this research is expected to save energy consumption and improve traveling safety for the aerodynamic control of vehicles.
Quantum mechanical approach to plasma waves with helical wavefront
Authors: Ishihara Osamu
Published: December 2023

Plasma waves with helical wavefront are studied theoretically from the quantum mechanical viewpoint and are shown to produce a spinning motion of a charged macroparticle in a complex plasma. The electrostatic helical perturbations are described by the wave function for a Laguerre–Gaussian beam mode with the radial/angular mode numbers n/l. The interaction and the transfer of angular momentum from the wave to a particle are analyzed by the method of second quantization with the help of the Feynman diagram. Laguerre function, instead of the Born approximation, is introduced to describe plasma waves with helical wavefront. A pair of dust particles in a complex plasma exchange a quasiparticle (virtual plasmon) resulting in the acquisition of angular momentum, which makes a dust particle spin in motion with rotational frequency Ωϕ. The resonance condition ω−kvz−lΩϕ=0 and the conservation of angular momentum IdΩϕ=lℏ determine the rotational frequency, where ω and k are frequency and axial wave number of the helical wave, and vz and Id are axial velocity and the moment of inertia of a dust particle.
ICE modes with high wave numbers
Authors: Kolesnichenko Ya. I. , Lutsenko V. V.
Published: December 2023

This work deals with high-k modes of the ion cyclotron emission (ICE)—the modes with frequencies close to ion cyclotron harmonics and wave numbers well exceeding those of fast magnetoacoustic modes (FMM). These modes exist due to finite Larmor radius of the ions. They are responsible for the ICE recently observed in the DIII-D tokamak [N. A. Crocker et al., Nucl. Fusion 62, 026023 (2022)]. The work is aimed at knowing the radial structure of high-k eigenmodes. Its analysis is relied on a comprehensive study carried out by employing a general dispersion equation for traveling waves, which allowed to group modes and determine conditions of their existence. Differential equations for various eigenmodes (standing waves) were obtained and analyzed. In particular, electrostatic modes and electromagnetic modes with various ratios of the longitudinal phase velocity to the electron thermal velocity were considered. A numerical code solving these equations was developed. It is found that high-k modes with sufficiently large poloidal mode numbers are located at the plasma periphery, and their amplitudes in the plasma core are very small. It is concluded that high-k modes are not an exceptional case, although presumably FMMs can explain most ICE experiments. They exist in plasmas with various magnitudes of β, representing different wave branches associated with finite Larmor radius of the ions. The mentioned experiment on DIII-D is discussed.
Floquet engineering of selective magnon–magnon coupling in synthetic antiferromagnets
Authors: Li Zhengyi , Sun Junwen , Ma Fusheng
Published: December 2023

Floquet engineering is a widely applied method for temporally periodic driving in various quantum systems, capable of inducing emergent phenomena, such as Floquet states, Floquet topological insulators, and temporal crystals. In this work, we study the selective magnon–magnon coupling between sidebands by introducing Floquet engineering into magnonic system: coupling between Floquet sidebands occurs only when there is an odd order difference. In addition to the coherent coupling between the optical and acoustic modes in synthetic antiferromagnet, a Floquet coupling is observed as the secondary splitting of the two hybridized magnon modes. The splitting width of Floquet coupling exhibits different dependence with driving amplitude, i.e., linearly increasing for weak driving regime and nonlinearly varying for strong driving regime. Specifically, the nonlinear dependence arises from the coupling between hybridized sidebands that exhibit odd order differences in their components. Our findings could promote the further development of Floquet magnonics and its application for quantum information.
Excess risk in infant mortality among populations living in flood-prone areas in Bangladesh: A cluster-matched cohort study over three decades, 1988 to 2017
Authors: Rerolle Francois , Arnold Benjamin F. , Benmarhnia Tarik
Published: December 2023

The Ganges–Brahmaputra–Meghna river basin, running through Tibet, Nepal, Bhutan, Bangladesh, and northern India, is home to more than 618 million people. Annual monsoons bring extensive flooding to the basin, with floods predicted to be more frequent and extreme due to climate change. Yet, evidence regarding the long-term impacts of floods on children’s health is lacking. In this analysis, we used high-resolution maps of recent large floods in Bangladesh to identify flood-prone areas over the country. We then used propensity score techniques to identify, among 58,945 mothers interviewed in six demographic population-based surveys throughout Bangladesh, matched cohorts of exposed and unexposed mothers and leverage data on 150,081 births to estimate that living in flood-prone areas was associated with an excess risk in infant mortality of 5.3 (95% CI 2.2 to 8.4) additional deaths per 1,000 births compared to living in non-flood-prone areas over the 30-y period between 1988 and 2017, with higher risk for children born during rainy (7.9, 95% CI: 3.3 to 12.5) vs. dry months (3.1, 95% CI: –1.1 to 7.2). Finally, drawing on national-scale, high-resolution estimates of flood risk and population distribution, we estimated an excess of 152,753 (64,120 to 241,386) infant deaths were attributable to living in flood-prone areas in Bangladesh over the past 30 y, with marked heterogeneity in attributable burden by subdistrict. Our approach demonstrates the importance of measuring longer-term health impacts from floods and provides a generalizable example for how to study climate-related exposures and long-term health effects.
Sending positive signals and good (calcium) vibes
Authors: Dominguez-Sola David
Published: December 2023

In this issue of JEM, Yada et al. (https://doi.org/10.1084/jem.20222178) demonstrate that effective antibody affinity selection in germinal centers relies on the store-operated calcium entry (SOCE) component of the B cell receptor (BCR) signaling network. Therefore, active BCR signaling is as relevant to positive selection as the function of BCRs as endocytic receptors, answering a question that had puzzled experts for a while. These findings transform our understanding of the mechanisms supporting adaptive immune responses (to vaccines, for example) and have important implications for interpreting the genomics and pathogenesis of germinal center–derived B cell lymphomas.
Transport and electrical properties of cryogenic thermoelectric FeSb2: the effect of isoelectronic and hole doping
Authors: Gujjar Deepak , Gujjar Sunidhi , Malik V K , Kandpal Hem C
Published: December 2023

Thermoelectric materials operating at cryogenic temperatures are in high demand for efficient cooling and power generation in applications ranging from superconductors to quantum computing. The narrow band-gap semiconductor FeSb2, known for its colossal Seebeck coefficient, holds promise for such applications, provided its thermal conductivity value can be reduced. This study investigates the impact of isoelectronic substitution (Bi) and hole doping (Pb) at the Sb site on the transport properties of FeSb2, with a particular focus on thermal conductivity (κ). Polycrystalline FeSb2 powder, along with Bi- and Pb-doped samples, were synthesized using a simple co-precipitation approach, followed by thermal treatment in an H2 atmosphere. XRD and SEM analysis confirms the formation of the desired phase pre- and post-consolidation using spark plasma sintering. The consolidation process resulted in a high compaction density and the formation of submicrometer-sized grains, as substantiated by electron backscattered diffraction analysis. Substituting 1% of Bi and Pb at the Sb site successfully suppressed the thermal conductivity (κ) from ∼15 W (m·K)−1 in pure FeSb2 to ∼10 and ∼8.7 W (m·K)−1, respectively. Importantly, resistivity measurements revealed a metal-to-insulator transition at around 6.5 K in undoped FeSb2 and isoelectronically Bi-substituted FeSb2, suggesting the existence of metallic surface states and provides valuable evidence for the perplexing topological behavior exhibited by FeSb2.
Insights and viewpoints from a small-scale survey on current nuclear disaster preparedness measures in Japan after the Fukushima Daiichi Nuclear Power Plant accident
Authors: Marui Hidenori , Sawano Toyoaki , Yamamoto Chika , Zhao Tianchen , Nonaka Saori , Nishikawa Yoshitaka , Ozaki Akihiko , Tsubokura Masaharu
Published: December 2023

In nuclear disaster prevention, it is essential not only to make daily efforts to prevent accidents from occurring but also to properly apply lessons learnt from actual disasters. Although significant changes have been made to nuclear disaster preparedness in Japan since the Fukushima Daiichi Nuclear Power Plant accident, there is insufficient information on whether these changes have been evaluated as practical and appropriate for the needs of the Japanese public. In this survey, 20 officials of the Cabinet Office and Japan Atomic Energy Agency, in charge of planning nuclear disaster prevention policy, were asked to evaluate the current nuclear disaster prevention plan through a questionnaire, and compare it with that before the accident, and indicate what elements are lacking in the current plan. The survey results revealed that 30% of the participants (six respondents) had a positive view of the enhancement of resources, including physical and human assets. However, as many as 60% (12 respondents) expressed negative sentiments, primarily due to perceived deficiencies in organisational measures, particularly the coordination of these resources. Moreover, the participants expressed keen interest in obtaining health data during evacuation, along with information on the physical and mental effects on evacuees living in evacuation centres. These crucial insights can inform the formulation of effective future preparedness plans for evacuation and radiation protection.
Global solutions to the tangential Peskin problem in 2-D
Authors: Tong Jiajun
Published: December 2023

We introduce and study the tangential Peskin problem in 2D, which is a scalar drift-diffusion equation with a nonlocal drift. It is derived with a new Eulerian perspective from a special setting of the 2D Peskin problem where an infinitely long and straight 1D elastic string deforms tangentially in the Stokes flow induced by itself in the plane. For initial datum in the energy class satisfying natural weak assumptions, we prove existence of its global solutions. This is considered as a super-critical problem in the existing analysis of the Peskin problem based on Lagrangian formulations. Regularity and long-time behaviour of the constructed solution is established. Uniqueness of the solution is proved under additional assumptions.
TDCAU-Net: retinal vessel segmentation using transformer dilated convolutional attention-based U-Net method
Authors: Li Chunyang , Li Zhigang , Liu Weikang
Published: December 2023

Retinal vessel segmentation plays a vital role in the medical field, facilitating the identification of numerous chronic conditions based on retinal vessel images. These conditions include diabetic retinopathy, hypertensive retinopathy, glaucoma, and others. Although the U-Net model has shown promising results in retinal vessel segmentation, it tends to struggle with fine branching and dense vessel segmentation. To further enhance the precision of retinal vessel segmentation, we propose a novel approach called transformer dilated convolution attention U-Net (TDCAU-Net), which builds upon the U-Net architecture with improved Transformer-based dilated convolution attention mechanisms. The proposed model retains the three-layer architecture of the U-Net network. The Transformer component enables the learning of contextual information for each pixel in the image, while the dilated convolution attention prevents information loss. The algorithm efficiently addresses several challenges to optimize blood vessel detection. The process starts with five-step preprocessing of the images, followed by chunking them into segments. Subsequently, the retinal images are fed into the modified U-Net network introduced in this paper for segmentation. The study employs eye fundus images from the DRIVE and CHASEDB1 databases for both training and testing purposes. Evaluation metrics are utilized to compare the algorithm’s results with state-of-the-art methods. The experimental analysis on both databases demonstrates that the algorithm achieves high values of sensitivity, specificity, accuracy, and AUC. Specifically, for the first database, the achieved values are 0.8187, 0.9756, 0.9556, and 0.9795, respectively. For the second database, the corresponding values are 0.8243, 0.9836, 0.9738, and 0.9878, respectively. These results demonstrate that the proposed approach outperforms state-of-the-art methods, achieving higher performance on both datasets. The TDCAU-Net model presented in this study exhibits substantial capabilities in accurately segmenting fine branching and dense vessels. The segmentation performance of the network surpasses that of the U-Net algorithm and several mainstream methods.
ABUS tumor segmentation via decouple contrastive knowledge distillation
Authors: Pan Pan , Li Yanfeng , Chen Houjin , Sun Jia , Li Xiaoling , Cheng Lin
Published: December 2023

Objective. In recent years, deep learning-based methods have become the mainstream for medical image segmentation. Accurate segmentation of automated breast ultrasound (ABUS) tumor plays an essential role in computer-aided diagnosis. Existing deep learning models typically require a large number of computations and parameters. Approach. Aiming at this problem, we propose a novel knowledge distillation method for ABUS tumor segmentation. The tumor or non-tumor regions from different cases tend to have similar representations in the feature space. Based on this, we propose to decouple features into positive (tumor) and negative (non-tumor) pairs and design a decoupled contrastive learning method. The contrastive loss is utilized to force the student network to mimic the tumor or non-tumor features of the teacher network. In addition, we designed a ranking loss function based on ranking the distance metric in the feature space to address the problem of hard-negative mining in medical image segmentation. Main results. The effectiveness of our knowledge distillation method is evaluated on the private ABUS dataset and a public hippocampus dataset. The experimental results demonstrate that our proposed method achieves state-of-the-art performance in ABUS tumor segmentation. Notably, after distilling knowledge from the teacher network (3D U-Net), the Dice similarity coefficient (DSC) of the student network (small 3D U-Net) is improved by 7%. Moreover, the DSC of the student network (3D HR-Net) reaches 0.780, which is very close to that of the teacher network, while their parameters are only 6.8% and 12.1% of 3D U-Net, respectively. Significance. This research introduces a novel knowledge distillation method for ABUS tumor segmentation, significantly reducing computational demands while achieving state-of-the-art performance. The method promises enhanced accuracy and feasibility for computer-aided diagnosis in diverse imaging scenarios.
Resonance magnetoelectric effect in a three-layer non-symmetric ring structure Ni/PZT/Metglas
Authors: Fetisov L Y , Savelev D V , Musatov V I , Fedulov F A , Fetisov Y K
Published: December 2023

The resonant magnetoelectric (ME) effect in a ring-type structure of nickel–lead zirconate titanate–Metglas amorphous alloy (Metglas 2605SA1) has been studied. The use of ring geometry and magnetic layers with different signs of magnetostriction and comparable saturation fields led to a noticeable enhancement in the ME coefficient and a decrease in the optimal bias field, as compared with two-layer planar heterostructures. At the frequency of radial acoustic oscillations of the structure and under circular magnetization, the ME coefficient of 6.4 V (Oe·cm)−1 and ac field sensitivity of 0.6 V Oe−1 were obtained for a permanent bias field of 2 Oe.