bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential Use of Hyperbaric Oxygen Therapy in Orthodontic Treatment: A Systematic Review of Animal Studies
Authors: Akbar Yun Mukmin , Maskoen Ani Melani , Mardiati Endah , Wandawa Ganesha , Setiawan Arlette Suzy
Published: October 2022

Understanding the fundamental principles of tooth movement could reduce the duration of treatment and achieve a stable outcome, resulting in patient satisfaction. Hyperbaric oxygen therapy was a modality in which a patient inhaled 100% O2 while subjected to high atmospheric pressure. Hyperbaric oxygen therapy facilitated the supply of oxygen to the human body's organs and tissues and served a variety of applications, including patient care and wound treatment. This review article aimed to describe animal studies of the potential effects of hyperbaric oxygen therapy in orthodontic therapy. It was conducted using a systematic literature review method, including searching PubMed and Google Scholar for publications relevant to the research topics. The search was filtered to include only research on orthodontic treatment and hyperbaric oxygen therapy and was published in any year. Articles that did not specify biological components of orthodontic tooth movement (OTM) were excluded. The Preferred Reporting Items identified the papers for the Systematic Reviews and Meta-Analyses (PRISMA) strategy, which resulted in the selection of 11 publications. Hyperbaric oxygen therapy affected parameters of biomarkers representing the clinical, molecular, and cellular biology of bone formation and resorption in periodontal tissues in responding to orthodontic physical forces, including alkaline phosphatase, collagen synthesis, osteoblast, osteoclast, osteocyte, type I collagen, vascular endothelial growth factor, osteocalcin, fibroblast, matrix metalloproteinase-8, transforming growth factor-β, partial pressure of oxygen, partial pressure of carbon dioxide, trabecular bone density, and tooth mobility. Hyperbaric oxygen therapy induced an inflammatory response to follow OTM events during active orthodontic therapy. Hyperbaric oxygen therapy might play a role in the tissue healing process during passive treatment. Nonetheless, additional research should be conducted to establish the efficacy of hyperbaric oxygen therapy in orthodontics.
Effect of Visual Exposure versus Obstruction upon Patient's Quantitative and Qualitative Stress Parameters Changes during Minor Oral Surgery
Authors: Subramaniam Pram Kumar , Al-Ahmad Basma Ezzat Mustafa , Mustafa Nazih Shaban , Izhan Natasha Athirah Mohd , Shukor Nur Farah Izzati Ahmad
Published: October 2022

Objectives Dental anxiety is ultimately related to the fear of pain, more evidently seen in surgical dental procedures. This study aimed at comparing the stress parameter differences between patients undergoing minor oral surgery (MOS) with their eyes covered (closed) versus uncovered (open) at our center.

Materials and Methods Twenty-three MOS patients were draped with eyes covered, while another 23 MOS patients were draped with eyes uncovered. Stress parameters such as systolic and diastolic blood pressures (DBP), mean arterial pressure (MAP), heart rate, random blood glucose, and Spielberger State-Trait Anxiety Inventory (STAI)-6 questionnaire score were recorded accordingly in the different intervals; then statistically analyzed later.

Results Closed eyes patients had significantly lower mean DBP and MAP (73.91 ± 6.80/88.94 ± 6.88 mm Hg) as compared with open eyes patients intraoperatively. Though significant only in the postoperative phase, the closed eyes group had a relatively lower mean heart pulse rate than the open eyes group in all surgical intervals. Postoperatively, closed eyes patients had lower mean blood glucose level as compared with open eyes group. STAI mean score revealed a higher psychological stress for closed eyes patients versus open eyes patients.

Conclusion Closed eyes patients displayed lower quantifiable physiological stress level as compared with patients undergoing MOS draped with eyes uncovered. However, in qualitative psychological context, closed eyes draped MOS patients responded poorly as compared with opened eyes draped patients under similar surgical stress.
The Clinical Characteristics and Prognosis of Children Presenting with New Onset Refractory Status Epilepticus in COVID-19 Related Multisystem Inflammatory Syndrome
Authors: Das Suman , Chatterjee Kaushani , Mondal Gobinda , Paul Dilip Kumar , Mishra Lopamudra
Published: October 2022

Multisystem inflammatory syndrome in children (MIS-C) is a hyperinflammatory process leading to multiorgan failure and shock, occurring during the acute or post-infectious stage of severe acute respiratory syndrome coronavirus (SARS-CoV-2), and has two subtypes: para-infectious and post-infectious varieties. The new onset of refractory status epilepticus has rarely been described as the presenting feature of MIS-C. This retrospective study, conducted at Dr. B.C. Roy Post Graduate Institute of Pediatric Sciences, included children hospitalized between August 1, 2020 and July 31, 2021, with new-onset refractory status epilepticus (NORSE) and subsequently diagnosed to have MIS-C. Their clinico-demographic variables, treatment courses during hospital stays, laboratory reports, radiological and electrophysiological findings, and outcomes at discharge and follow-up over 1 year were recorded. At their 12 month visits, their motor disabilities (primary) and continuation of anti-epileptic drugs, and persistence of magnetic resonance imaging (MRI) brain abnormalities (secondary) were the outcome measures. The characteristics of the patients in the para-infectious and post-infectious groups were compared using the Mann-Whitney U test for continuous variables and the Chi-square test for categorical variables. There were eight and 10 patients in groups A and B, respectively. Patients in group B had significantly higher age, more prolonged refractory status epilepticus (RSE), use of anesthetics and ventilation, and longer pediatric intensive care unit (PICU) stay, while other clinical and laboratory parameters and short and long-term outcomes were not significantly different between the two groups. Eight patients developed hemiparesis, while two had quadriparesis in the acute stage, but 15 (83%) patients had complete recovery from their motor deficits by 1 year. At 1-year follow-up, 33 and 39% of patients, respectively, had abnormal MRI and electroencephalogram (EEG). Acute disseminated encephalitis and acute leukoencephalopathy were the most commonly observed MRI abnormalities in the acute phase, with prolonged persistence of cerebritis in patients in the post-infectious group, warranting long-term immunomodulation. Combined immunotherapy with intravenous immunoglobulin and steroids was effective in the acute phase. However, long-term anti-epileptic therapy was needed in both groups.
Prevalence, Prevention, and Treatment of Work-Related Musculoskeletal Disorders Among Microsurgeons
Authors: Zhao Ruya , Rothchild Evan , Wang Fei , Nash David , Greige Nicolas , Lala Brittany , Ricci Joseph A.
Published: October 2022

Background While work related musculoskeletal disorders have been well recognized among all surgeons, and microsurgeons in particular; their prevention and treatment are presently unknown. Our study aims to define the impact of musculoskeletal ailments on microsurgeons and investigate trends in microsurgeon musculoskeletal injury treatment.

Methods An electronic survey was sent to all members of the American Society of Reconstructive Microsurgery. The survey solicited surgeon demographics, microsurgical volume, equipment usage, history of musculoskeletal injury, impact of injury, and interventions / treatment modalities used to address / prevent these issues.

Results Of the 883 microsurgeons surveyed, 203 responded (23% response rate). The average age was 45 years (IQR 39–52 years). Most microsurgeons were male (80.8%). Musculoskeletal injury or symptoms related to microsurgery were reported by 137 respondents (67.0%). Fifty surgeons (37.9%) reported that their musculoskeletal injury had adversely affected their practice. Formal medical intervention was sought by 53 respondents (26.1%), with 17 surgeons (8.4%) undergoing surgical intervention. Self-treated was used by 127 microsurgeons (62.6%) for musculoskeletal ailments. Preventative treatments such as strength training, stretching, yoga, massages, and diet were the most beneficial, each with utilization scores of 4 out of 5.

Conclusion A majority of microsurgeons experience musculoskeletal injury, and some even require surgery to treat their musculoskeletal pathology. Prophylactic practices such as strength training, stretching, yoga, massages, and diet maintenance, are the superior treatment for musculoskeletal injury. Microsurgeons should incorporate training routines in their lives as injury prophylaxis to improve their career longevity and patient care.
Circular DNA shows promise for molecular electronics components
Authors: Johnson-Groh Mara
Published: October 2022

Theoretical study found Aharonov-Bohm-like effects and Fano resonances in circular DNA connected to two electrodes.
Quantum earth mover’s distance, a no-go quantum Kantorovich–Rubinstein theorem, and quantum marginal problem
Authors: Zhou Li , Yu Nengkun , Ying Shenggang , Ying Mingsheng
Published: October 2022

The quantum coupling of two given quantum states denotes the set of bipartite states whose marginal states are these given two states. In this paper, we provide tight inequalities to describe the structure of quantum coupling. These inequalities directly imply that the trace distance between two quantum states cannot be determined by the quantum analog of the earth mover’s distance, thus ruling out the equality version of the quantum Kantorovich–Rubinstein theorem for trace distance even in the finite-dimensional case. In addition, we provide an inequality that can be regarded as a quantum generalization of the Kantorovich–Rubinstein theorem. Then, we generalize our inequalities and apply them to the three tripartite quantum marginal problems. Numerical tests with a three-qubit system show that our criteria are much stronger than the known criteria: the strong subadditivity of entropy and the monogamy of entanglement.
Analytical solutions to the compressible Euler equations with time-dependent damping and free boundaries
Authors: Dong Jianwei , Li Jingjing
Published: October 2022

In this paper, we study a class of analytical solutions to the compressible Euler equations with time-dependent damping μ(1+t)λρU, which describe compressible fluids moving into outer vacuum. Under the continuous density condition across the free boundaries separating the fluid from vacuum, we construct a class of spherically symmetric and self-similar analytical solutions in R3. The global-in-time existence of such solutions is proved for μ > 0 and λ > 1. Moreover, the free boundary tends to +∞ at an algebraic rate not more than C(1 + t)2 as t → +∞.
Dynamics of non-autonomous first order lattice systems in weighted spaces
Authors: Abdallah Ahmed Y. , Abu-Shaab Heba N. , Al-Khader Taqwa M. , Wannan Rania T.
Published: October 2022

In a weighted Hilbert space, the existence of a uniform global attractor for a family of first order non-autonomous deterministic lattice dynamical systems with a nonlinear part of the form ft,u=fit,ui−m,…,ui+mi∈Z is carefully investigated, where ft,⋅ is an element of the hull of an almost periodic function in a suitable Banach space.
Experimental study of coherent wall-pressure fluctuations associated with the turbulent near wake of a cylinder
Authors: Hernández R. H.
Published: October 2022

The objective of this work is to present a coherent detection method to determine relationships between pressure fluctuations and wake velocity in the case of the flow past a cylinder in a turbulent regime. We report experimental results and pressure–velocity statistics measured simultaneously on the surface boundary layer and the near wake in the range of Reynolds numbers (2×103<Re<3.5×104). The novelty of the analysis lies in the application of a coherent mean method to determine conditioned wall pressure statistics to velocity events observed in the turbulent cylinder wake. The method allows one to associate wake turbulent events with a corresponding wall-pressure signal profile on the cylinder surface performing discrete angular measurements with a minimum number of pressure sensors. Simultaneous measurements of both time series of wake velocity and wall pressure allow us to characterize the mutual influence of hydrodynamic perturbations from the boundary layer surface pressure with the near wake velocity fluctuations. Large scale turbulent vortex shedding is well correlated with surface pressure fluctuations as expected in the low frequency range. Near wake velocity signals were used as timing signals to determine the coherent influence of a representative velocity pattern on the statistical properties of wall pressure fluctuations. The dynamics of low-frequency large-scale structures is consistent with the presence of counter-rotating vortices and is well correlated with a great part of the pressure fluctuations of the boundary layer. Conditional statistics using the velocity pattern obtained from the coherent averaging method provided the instantaneous pressure fluctuating profile associated with the large-scale vortex shedding cycle, thus, enabling a coherent estimation of the fluctuating lift and drag forces. Conditional statistics on wake velocity are well influenced by the phase of the vortex life-cycle.
A comprehensive study of the onset of boundary layer separation in the unbounded flow around a circular cylinder
Authors: Malamataris N. A. , Sarris I. E. , Pazis D. P. , Liakos A.
Published: October 2022

The onset of boundary layer separation in the unbounded flow around a circular cylinder is determined directly with a numerical experiment with accuracy to the second decimal point of the Reynolds number, Re. The governing equations are the steady state, two dimensional Navier–Stokes equations, which are solved with Galerkin finite elements. A new criterion, the entrance ratio E=D/L with D the diameter of the cylinder and L the entrance length of the domain, is introduced in addition to the traditional blockage ratio; the aim is to establish conditions for unbounded flow in both flow directions. A hypothesis is formulated and verified for the onset of separation leading to the conclusion that this flow undergoes a supercritical pitchfork bifurcation with respect to fixed points on the boundary. Results are presented for various blockage ratios, B, in the range 1.2238·10−8≤B≤0.005 and constant entrance ratio E=2.4472·10−9 until asymptotic behavior is observed for the onset of separation in the Reynolds number, in the angle and the length of the smallest eddy. Onset of separation occurs in the region 6.36≤Re<6.37. The bifurcation diagram of the flow is calculated. Streamlines of the flow domain before and after the bifurcation point are shown, including images of the smallest possible eddies. In addition, coefficients of base suction and total drag are computed and shown in the regime 0.1≤Re≤40. The results are compared with available laboratory and numerical measurements.
Broadband and efficient asymmetric wavefront manipulation via terahertz polarization-selective metasurface
Authors: Wang Yan , Li Shaohe , Wang Hui , Feng Longcheng , Tan Bowen , Tan Yihui , Su Runfeng , Wu Jingbo , Zhang Caihong , Jin Biaobing , Chen Jian , Wu Peiheng
Published: October 2022

Asymmetric manipulation of electromagnetic waves exhibits tremendous capabilities in the applications of encryption, ultrafast information processing, and communication. However, compact and broadband terahertz (THz) components for asymmetric applications are still scarce. Here, we demonstrate broadband, ultrathin, and efficient metasurface-based asymmetric transmission and wavefront manipulation in the THz region. The metasurface consists of tri-layer metallic structures separated by two flexible polyimide dielectrics. This ultrathin structure exhibits superior asymmetric response which can act as an efficient device with a high linear polarization conversion ratio over 0.9 ranging from 0.5 to 1.1 THz. We also develop THz asymmetric applications based on the flexible metasurface for beam deflector and orbital angular momentum generation. The THz time-domain spectroscopy system and spectral imaging system are used to characterize the broadband asymmetric properties. The experimental results confirm that the beam deflection and vortex waves can be realized over broadband under one linearly polarized incidence while blocked under its orthogonal incidence. This work may provide a promising route to achieve broadband asymmetric applications in information encryption, THz wireless communication, and spectroscopy applications.
Measurements of thermoelectric figure of merit based on multi-harmonic thermal analysis of thermographic images
Authors: Alasli Abdulkareem , Hirai Takamasa , Nagano Hosei , Uchida Ken-ichi
Published: October 2022

We demonstrate a versatile measurement method for the thermoelectric figure of merit and related transport properties by means of a multi-harmonic thermal analysis of a thermographic movie. The method is based on the thermal analyses of the charge-current-induced temperature distribution generated by the Peltier effect at the first harmonic and by Joule heating at the second harmonic, measured with an infrared camera. This allows simultaneous estimation of the thermal diffusivity, thermal conductivity, volumetric heat capacity, and Peltier/Seebeck coefficient of conductors without attaching an external heater. The thermal analysis developed here is applicable to a system with the interfacial thermal resistance between the target conductor and reference material. Our method enables the measurements while applying an external magnetic field, opening the way for investigating the magnetic field and/or magnetization dependences of the figures of merit and associated properties for the magneto-thermoelectric effects. We demonstrate the usability of this method by estimating the figures of merit for the Peltier/Seebeck, magneto-Peltier/Seebeck, and Ettingshausen/Nernst effects in a Bi–Sb alloy as a promising material for thermoelectric applications. The multi-harmonic thermal analysis method will, thus, aid in developing highly efficient thermoelectric materials and further investigations of magneto-thermal and magneto-thermoelectric transport properties.
A 3D printed sandwich-type piezoelectric motor with a surface texture
Authors: Liu Ruixuan , Li Xiaoniu , Yu De , Cao Teng , Cao Jia , Wang Boquan , Wu Dawei
Published: October 2022

Polymer-based piezoelectric motors have excellent properties, such as lightweight and corrosion resistance. In addition, 3D printing and customized additive manufacturing of polymers provide new opportunities for the development of piezoelectric motors with complex or special structures. In this paper, a 3D printed polymer-based sandwich-type piezoelectric motor operating in a single longitudinal mode is developed. A vibration decomposition model of the motor and an analytical model considering polymer viscoelasticity are established to analyze the dynamic characteristics and to determine the geometric structure of the motor. To increase the coefficient of friction, a polymer surface texture is utilized on the contacts. The experimental results show that the friction coefficient of the contact tip with surface texture is about 0.16, which increased by 45.5% compared to a smooth surface. The resonance frequency is 28.648 kHz, and the maximum no-load speed under 300 Vp-p is 54 r/min. Our study shows the promise of polymer-based materials in the development of the piezoelectric motor.
Anisotropy-induced spin disorder in intergrown, ferrimagnetic Fe7S8 polytypes
Authors: Firlus Alexander , Schawe Jürgen E. K. , Weidler Peter G. , Charilaou Michalis , Löffler Jörg F. , Gehring Andreas U.
Published: October 2022

The monosulfides of the pyrrhotite omission series (Fe1−xS, 0<x≤0.125) are important remanence carriers for paleomagnetic reconstruction of the Earth's crust and extraterrestrial materials. The ferrimagnetic Fe7S8 polytypes are the endmembers, and their stacking modulations of full and vacant layers generate different magnetic anisotropy properties due to the cation-vacancy configurations. In this study, intergrown long-range ordered polytypes with four- and threefold modulation, i.e., 4C and 3C pyrrhotite, were prepared in a diffusion-driven process by quenching of a natural pyrrhotite crystal with randomized vacancies. In addition, a third constituent with coherence lengths of a few nanometers, denoted 3C*, was found that exhibits spin-glass behavior at about 10 K due to local magnetic anisotropies arising from vacancy-density variations. The concomitant occurrence of this nano-scale constituent with spin disorder and the long-range ordered polytypes indicate competitive diffusion-driven processes during Fe7S8 formation. Such information provides insight into the provenance and genesis of ferrimagnetic pyrrhotite in Earth and extraterrestrial systems and in a broader sense into vacancy-induced materials.
Use of combined linear and nonlinear formalisms applied to the transport of protons and secondary electrons in a Monte Carlo code: Applications for space missions
Authors: Caron P. , Inguimbert C. , Gibaru Q. , Pinson M.
Published: October 2022

A review of linear (dielectric theory) and nonlinear (binary collision theory) formalisms is proposed. The range of validity of both theories is discussed. The differential energy cross sections are fully detailed so that they are suitable for use in any Monte Carlo code. The use of the nonlinear formalism (and consequently the description of the differential cross sections) in a Monte Carlo code, such as GEANT4, is poorly addressed in the literature. In order to cover a very wide energy range, a combined model is discussed and implemented in GEANT4. Applications related to the space domain are studied, and the benefit of our combined model is investigated through a dedicated code devoted to the estimation of deposited energy in nanometric volumes.
Impact of pearl-necklace-like skeleton on pore sizes and mechanical properties of porous materials: A theoretical view
Authors: Rege Ameya , Aney Shivangi , Ratke Lorenz
Published: October 2022

The structural and mechanical properties of open-porous cellular materials are often described in terms of simple beam-based models. A common assumption in these models is that the pore walls have a constant cross section, which may be in agreement for a vast majority of such materials. However, for many of those materials that are characterized by a pearl-necklace-like network, this assumption seems too idealized. Aerogels are perfect examples of such materials. In this paper, we investigate the effect of such pore walls having a string of pearls-like morphology on the properties of such open-porous materials. First, the pore size is mathematically modeled. Three scenarios are described, where the pore sizes are calculated for cells in 2D, 3D, and 3D with overlapping particles. The dependency of the skeletal features on the resulting pore size is investigated. In the second part, pore walls with 3D overlapping spheres are modeled and subjected to axial stretching, bending, and buckling. The effect of the particle sizes and the amount of overlap between the particles on the mechanical features is simulated and illustrated. The results are also compared with models that assume a constant cross section of pore-walls. It can be observed that neglecting the corrugations arising from the pearl-necklace-like morphology in open-porous cellular materials can result in serious miscalculations of their mechanical behavior. The goal of this paper is not to quantify the bulk mechanical properties of the materials by accounting for the pearl-necklace-like morphology but rather to demonstrate the significant deviations that may arise when not accounted for.
A dynamic version of the improved delayed detached-eddy simulation based on the differential Reynolds-stress model
Authors: Li Quanzheng , Chen Xin , Wang Gang , Liu Yi
Published: October 2022

A dynamic version of the improved delayed detached-eddy simulation (IDDES) based on the differential Reynolds-stress model (RSM), referred to as the RSM-DynIDDES, is developed by applying the dynamic Smagorinsky subgrid model to the large eddy simulation (LES) branch of the IDDES. The RSM-DynIDDES simulates the periodic hills flow after a basic numerical validation for the decaying isotropic turbulence simulation. Well-predicted velocity profiles and R eynolds stress distributions are obtained by the RSM-DynIDDES in the periodic hills flow. The simulation results indicate that the RSM-DynIDDES can capture more small-scale vortex structures in the LES region away from the wall than the original RSM-based IDDES (RSM-IDDES). The RSM-DynIDDES is also employed in simulating the transonic buffeting of a launch vehicle with a payload fairing. The numerical results have been compared with that of the RSM-IDDES. It is found that the RSM-DynIDDES can improve turbulence resolution in the off-wall region while retaining the advantages of the original RSM-IDDES in simulating the instability process of the free shear layer.
Implicit block data-parallel relaxation scheme of Navier–Stokes equations using graphics processing units
Authors: Zhou Bohao , Huang Xudong , Zhang Ke , Bi Dianfang , Zhou Ming
Published: October 2022

The granularity of computational fluid dynamics (CFD) generally refers to the point granularity parallelization as a unit of the grid when graphics processing units (GPUs) are utilized as the computing carrier. In commonly deployed implicit time advancement schemes, the parallel dimensionality must be reduced, resulting in the time advancement procedure becoming the only highly time-consuming step in the whole CFD computing procedures. In this paper, a block data-parallel lower-upper relaxation (BDPLUR) scheme based on Jacobi iteration and Roe's flux scheme is proposed and then implemented on a GPU. Numerical experiments are carried out and show that the convergence speed of the BDPLUR scheme, especially when implemented on a GPU, is approximately ten times higher than that of the original data-parallel lower-upper relaxation scheme and more than 100 times higher than that of the lower-upper symmetric Gauss–Seidel scheme. Moreover, the influence of different Courant–Friedrichs–Lewy numbers on the convergence time is discussed, and different viscous matrices are compared. Standard cases are adopted to verify the effectiveness of the BDPLUR scheme.
Dynamics of bypass transition behind roughness element subjected to pulses of free-stream turbulence
Authors: Vaid Aditya , Vadlamani Nagabhushana Rao , Malathi Ananth Sivaramakrishnan , Gupta Vikrant
Published: October 2022

This study explores the dynamics of bypass transition of a zero pressure gradient boundary layer transitioning under the combined influence of an isolated roughness element with pulses of free-stream turbulence (FST). We consider a hemispherical roughness element placed over a flat plate, while the pulses of FST are introduced at the inlet, which is in contrast to continuous FST largely explored in the literature. For a fixed turbulence intensity and length scale, a series of eddy-resolving simulations are carried out to examine the effect of varying the pulsing frequency of FST. The flow behind the roughness element remains stable in the absence of FST for the subcritical Reynolds number Rek = 400 considered in this study. We observe that with the pulses of FST, the transition is triggered due to the interaction of the FST-induced Klebanoff streaks with the roughness-induced streamwise vortices. With an increase in the frequency of FST pulses, the boundary layer has less time to relax to its unperturbed state resulting in an earlier onset of transition. The transition onset predicted is in favorable agreement with the correlations proposed in the literature. We analyze the growth of disturbance kinetic energy, the shape of secondary instabilities over the streaks, and their phase speeds in detail. The FST pulse convecting over the roughness element triggers the inner varicose modes in its near-wake region. The varicose modes decay rapidly further downstream and the well-known sinuous instabilities (or the outer modes) trigger transition via transient growth associated with convective instabilities. Such clear identification of the sinuous and varicose instabilities is not usually observed in cases with continuous FST, highlighting the importance of our study in applications involving transition under intermittent turbulence.
Frozen propagation of Reynolds force vector from high-fidelity data into Reynolds-averaged simulations of secondary flows
Authors: Amarloo Ali , Forooghi Pourya , Abkar Mahdi
Published: October 2022

Successful propagation of information from high-fidelity sources (i.e., direct numerical simulations and large-eddy simulations) into Reynolds-averaged Navier–Stokes (RANS) equations plays an important role in the emerging field of data-driven RANS modeling. Small errors carried in high-fidelity data can propagate amplified errors into the mean flow field, and higher Reynolds numbers worsen the error propagation. In this study, we compare a series of propagation methods for two cases of Prandtl's secondary flows of the second kind: square-duct flow at a low Reynolds number and roughness-induced secondary flow at a very high Reynolds number. We show that frozen treatments result in less error propagation than the implicit treatment of Reynolds stress tensor (RST), and for cases with very high Reynolds numbers, explicit and implicit treatments are not recommended. Inspired by the obtained results, we introduce the frozen treatment to the propagation of the Reynolds force vector (RFV), which leads to less error propagation. Specifically, for both cases at low and high Reynolds numbers, the propagation of RFV results in one order of magnitude lower error compared to the RST propagation. In the frozen treatment method, three different eddy-viscosity models are used to evaluate the effect of turbulent diffusion on error propagation. We show that, regardless of the baseline model, the frozen treatment of RFV results in less error propagation. We combined one extra correction term for turbulent kinetic energy with the frozen treatment of RFV, which makes our propagation technique capable of reproducing both velocity and turbulent kinetic energy fields similar to high-fidelity data.
X-ray nano-imaging of defects in thin film catalysts via cluster analysis
Authors: Luo Aileen , Gorobtsov Oleg Yu. , Nelson Jocienne N. , Kuo Ding-Yuan , Zhou Tao , Shao Ziming , Bouck Ryan , Cherukara Mathew J. , Holt Martin V. , Shen Kyle M. , Schlom Darrell G. , Suntivich Jin , Singer Andrej
Published: October 2022

Functional properties of transition-metal oxides strongly depend on crystallographic defects; crystallographic lattice deviations can affect ionic diffusion and adsorbate binding energies. Scanning x-ray nanodiffraction enables imaging of local structural distortions across an extended spatial region of thin samples. Yet, localized lattice distortions remain challenging to detect and localize using nanodiffraction, due to their weak diffuse scattering. Here, we apply an unsupervised machine learning clustering algorithm to isolate the low-intensity diffuse scattering in as-grown and alkaline-treated thin epitaxially strained SrIrO3 films. We pinpoint the defect locations, find additional strain variation in the morphology of electrochemically cycled SrIrO3, and interpret the defect type by analyzing the diffraction profile through clustering. Our findings demonstrate the use of a machine learning clustering algorithm for identifying and characterizing hard-to-find crystallographic defects in thin films of electrocatalysts and highlight the potential to study electrochemical reactions at defect sites in operando experiments.
The Deep End GP Pioneer Scheme: a qualitative evaluation
Authors: Dhanani Safiya , Blane David N.
Published: October 2022

Background The Scottish Deep End Project is a collaboration between academic GPs and GPs in practices serving the most socio-economically disadvantaged populations in Scotland. The Deep End GP Pioneer Scheme was established in 2016 to improve GP recruitment and retention in these areas. The aim of this study was to qualitatively evaluate the experiences of participating lead GPs and GP fellows. Methods Semi-structured interviews were conducted with nine lead GPs and 10 GP fellows, representing 12 of the 14 practices involved. Interviews were audio-recorded, transcribed verbatim, and analysed thematically. Results Five main themes are presented: Recruitment to the Pioneer Scheme; Work motivation and satisfaction; Mitigating health inequalities; Retention and changes in work pattern; and Suggestions for the future. Key ingredients of the scheme were the additional clinical capacity (addressing the inverse care law), protected time for both GP fellows and experienced GPs to lead on service development initiatives and to share learning within and between practices, and the shared ethos and values of the Scheme. Conclusions There was strong support for the Scheme as a mechanism to improve GP recruitment and retention in areas of high socio-economic disadvantage, and to improve quality of care in these areas. As similar schemes are rolled out across the UK, there is a need for further research to evaluate their impact on workforce and patient outcomes in deprived areas.
Prenatal exposure to maternal social disadvantage and psychosocial stress and neonatal white matter connectivity at birth
Authors: Lean Rachel E. , Smyser Christopher D. , Brady Rebecca G. , Triplett Regina L. , Kaplan Sydney , Kenley Jeanette K. , Shimony Joshua S. , Smyser Tara A. , Miller J. Phillip , Barch Deanna M. , Luby Joan L. , Warner Barbara B. , Rogers Cynthia E.
Published: October 2022

Early life adversity (social disadvantage and psychosocial stressors) is associated with altered microstructure in fronto-limbic pathways important for socioemotional development. Understanding when these associations begin to emerge may inform the timing and design of preventative interventions. In this longitudinal study, 399 mothers were oversampled for low income and completed social background measures during pregnancy. Measures were analyzed with structural equation analysis resulting in two latent factors: social disadvantage (education, insurance status, income-to-needs ratio [INR], neighborhood deprivation, and nutrition) and psychosocial stress (depression, stress, life events, and racial discrimination). At birth, 289 healthy term-born neonates underwent a diffusion MRI (dMRI) scan. Mean diffusivity (MD) and fractional anisotropy (FA) were measured for the dorsal and inferior cingulum bundle (CB), uncinate, and fornix using probabilistic tractography in FSL. Social disadvantage and psychosocial stress were fitted to dMRI parameters using regression models adjusted for infant postmenstrual age at scan and sex. Social disadvantage, but not psychosocial stress, was independently associated with lower MD in the bilateral inferior CB and left uncinate, right fornix, and lower MD and higher FA in the right dorsal CB. Results persisted after accounting for maternal medical morbidities and prenatal drug exposure. In moderation analysis, psychosocial stress was associated with lower MD in the left inferior CB among the lower-to-higher socioeconomic status (SES) (INR ≥ 200%) group, but not the extremely low SES (INR < 200%) group. Increasing access to social welfare programs that reduce the burden of social disadvantage and related psychosocial stressors may be an important target to protect fetal brain development in fronto-limbic pathways.
Effect of cylinder liner cast iron microstructure on friction and wear process
Authors: Zhang Baofeng , Ma Xuan , Lu Xiqun , Song Yang , Shi Yufeng , Fu Yudong
Published: October 2022

The diversified microstructure and complex composition of cast iron affect its friction and wear properties. In this work, three kinds of cylinder liner cast iron with different graphite morphologies were selected to analyse the friction and wear properties. Microstructure effects on tribological properties during friction were investigated by finite element simulation and pin-on-disc dry friction test. Wear mechanisms were studied using scanning electron microscopy and X-ray photoelectron spectroscopy. The results show that graphite bears a considerable strain value during the friction process, which is prone to wear and fall off, and the fallen graphite can reduce the friction coefficient. Ferrite around graphite can buffer stress, but it also can reduce wear resistance. And the more significant the lamellar spacing of pearlite, the more abrasive and adhesive effect.
Lysosomal solute and water transport
Authors: Hu Meiqin , Zhou Nan , Cai Weijie , Xu Haoxing
Published: October 2022

Lysosomes mediate hydrolase-catalyzed macromolecule degradation to produce building block catabolites for reuse. Lysosome function requires an osmo-sensing machinery that regulates osmolytes (ions and organic solutes) and water flux. During hypoosmotic stress or when undigested materials accumulate, lysosomes become swollen and hypo-functional. As a membranous organelle filled with cargo macromolecules, catabolites, ions, and hydrolases, the lysosome must have mechanisms that regulate its shape and size while coordinating content exchange. In this review, we discussed the mechanisms that regulate lysosomal fusion and fission as well as swelling and condensation, with a focus on solute and water transport mechanisms across lysosomal membranes. Lysosomal H+, Na+, K+, Ca2+, and Cl− channels and transporters sense trafficking and osmotic cues to regulate both solute flux and membrane trafficking. We also provide perspectives on how lysosomes may adjust the volume of themselves, the cytosol, and the cytoplasm through the control of lysosomal solute and water transport.
Galactic dynamics in general relativity: the role of gravitomagnetism
Authors: Ruggiero Matteo Luca , Ortolan Antonello , Speake Clive C
Published: October 2022

It is a well-known fact that, in the absence of dark matter, the observation of the rotation curves of galaxies cannot be explained in terms of Newtonian gravity. Rotation curves become flat in the outer regions, in contrast to what is expected according to Keplerian motion. Far from the galactic center, the gravitational field is supposed to be weak enough so we expect to be able to use Newtonian gravity; however, even in the weak-field approximation, there are general relativistic effects without a Newtonian counterpart, such as the gravitomagnetic effects originating from mass currents. Using the gravitoelectromagnetic approach to the solution of Einstein equations in the weak-field and slow-motion approximation, we discuss some simple arguments that suggest the surprising result that gravitomagnetic effects may have a relevant role in better understanding the impact of dark matter on galactic dynamics. In addition, treating matter as a fluid of dust, we study the influence of post-Newtonian effects on the fluid vorticity.
Redistribution of translational kinetic energy: the surprises of bounces
Authors: D’Angelo Christophe , Viennot Laurence , Argentina Médéric , Celestini Franck , Raufaste Christophe
Published: October 2022

The topic of collisions is introduced in university education to address the laws of conservation of momentum and energy. In particular, students are asked to classify collisions as either elastic or inelastic. They are often left with the idea that ‘macroscopic energy’ has been transformed into ‘microscopic energy’ in the case of an inelastic collision, but their understanding of the processes of redistribution of kinetic energy to other degrees of freedom, often called ‘dissipation’, is mostly very poor. The aim of this article is to see how to facilitate the understanding of these processes among university students. Firstly, the results of a questionnaire with 27 university students show that they consider mass and material as the most important determinants of the coefficient of restitution of the bounce of a ball on a solid and rigid support, while the notion of internal structure, which is however essential, is not considered. Second, a simple model contextualizes the idea of a temporal sequence of successive events in the rebound of inhomogeneous projectiles. Finally, recent results on bilayered projectiles are exploited to emphasize the non-trivial influence of the structure of a body on the restitution of its initial translational kinetic energy after rebound on a support. These different elements contribute to conceive possible teaching objectives, to propose simple experiments and to address the conditions for progress in this field.
Fabrication of microstructures in the bulk and on the surface of sapphire by anisotropic selective wet etching of laser-affected volumes
Authors: Capuano L , Berenschot J W , Tiggelaar R M , Feinaeugle M , Tas N R , Gardeniers J G E , Römer G R B E
Published: October 2022

In this paper a processing technique for sapphire is presented which combines laser-induced amorphization and subsequent selective wet etching of amorphized sapphire as well as anisotropic wet etching of single-crystalline sapphire (α-Al2O3). Using this technique, microstructures can be realized on the surface and in the bulk of sapphire substrates. By focusing ultra-short laser pulses inside sapphire, its structure can be transformed from crystalline into amorphous. The modified material can be selectively removed using etchants, such as hydrofluoric acid or potassium hydroxide (KOH), solely dissolving the amorphized part. In this work, however, an etchant consisting of a standard solution of sulphuric acid and phosphoric acid (96 vol% H2SO4: 85 vol% H3PO4, 3:1 vol%) at 180 °C is utilized. This method allows the realization of structures which are impossible to achieve when using conventional etchants which solely dissolve the amorphized sapphire. Ultrashort pulsed laser irradiation (230 fs) is used in this study as starting point for the subsequent anisotropic etching to form microstructures on the surface or in the bulk of sapphire that are terminated by characteristic crystal planes. In particular, the appearance of etching-induced patterns formed by stacks of rhombohedra is shown for structures below the surface, whereas triangular pits are achieved in surface processing.
Electron-impact ionization of the tantalum atom
Authors: Pindzola M S , Loch S D , Colgan J P
Published: October 2022

Electron-impact ionization cross sections for the ground configuration of the tantalum (Ta) atom are calculated using a combination of non-perturbative time-dependent close-coupling and perturbative distorted-wave methods. Direct ionization of the 6s and 5d subshells leading to single ionization are presented. The inclusion of a polarization potential in the 6s direct ionization leads to a small reduction in the cross section. Angular factors are included that allow the configuration-average direct ionization cross sections to be split into LS term resolution. The magnitude of the ionization cross section suggests that the ionization mean free path for neutral Ta will be similar to that for tungsten (W) plasma facing components in fusion experiments, leading to similarly large fractions of prompt redeposition.
Electron transport characteristics in dual gate-controlled 30 nm-thick silicon membrane
Authors: Zhao Shuai , Yuan Guodong , Zhang Di , Liu Yumeng , Lu Jun , Han Weihua , Luo Junwei
Published: October 2022

The exploration of multi-gate-controlled electron transport characteristics is always a research focus in Si-based device development and optimization. In this work, we report individual and dual gate-controlled energy band regulations of 30 nm-thick Si membrane and the resulted electron transportations at 10–300 K. It is discovered that the fine energy band structure is a key element to determine electron transport behaviors in fully-depleted silicon-on-insulator. Furthermore, either the front or the back gate bias can modify the energy band bending and sub-band gap, change charged body distribution and intersub-band transition probability, and thus adjust electron mobility and device performance. This dual gate coupling effect together with the proposed gate-controlled sub-band structure model is confirmed by magnetotransport experiments at 1.6 K. Notably, our work presents the coupled gate controlling effects within ultrathin Si film, and gives a physical insight into electron structure modulating, which may promote the evolution of Si-based device applications in many domains.
Deformation dependence of 2p-radioactivity half-lives: probe with a new formula across the mass region with Z < 82
Authors: Saxena G , Aggarwal Mamta , Singh D , Jain A , Sharma P K , Yadav H L
Published: October 2022

Effect of deformation on half-life of two-proton (2p) radioactivity is investigated across the periodic chart for nuclei with Z < 82. 2p-decay half-lives are estimated by employing our newly proposed semi-empirical formula wherein the nuclear deformation has been incorporated in a phenomenological way. Robustness of the formula is demonstrated as it estimates the measured values quite accurately and, hence, reliably applied to predict the other possible 2p-emitters. For many proton rich nuclei for which experimental data on the decay energies are not available, we have used the theoretical values obtained from our calculations using the relativistic mean-field approach. The uncertainties in the theoretical decay energy values are minimised by machine learning technique. Correlation of 2p-radioactivity with 2p-halo and deformation is probed. Our calculations show the phenomenon of shape coexistence in several 2p-emitters, wherein the prolate shape is found to be more predominant for the ground state.
Topological defects in Haldane model and higher Chern numbers in monolayer graphene
Authors: Chang Zhi-Wen , Hao Wei-Chang , Liu Xin
Published: October 2022

We consider the Haldane model, a two-band model in monolayer graphene with non-trivial Chern numbers. Two types of topological defects, monopoles and merons, are derived from the model: (a) the monopole defects occur at the Dirac points, where the system experiences a topological transition and the Chern number C takes an indeterminate value. The sign-change of the mass term after this transition indicates different topological states labeled by different C numbers; (b) the meron defects occur as per a varying mass term. Summing up the topological charges of the merons leads to the C evaluation for the energy bands of an insulating bulk, and the result we obtain is in full agreement to the past literature. Furthermore, in this paper we propose a high-C model through studying the limitation behavior of the Hamiltonian vector in the neighborhood of the topological defects. It is discovered that two conducting states may arise form the edges, where the lower band of the insulating bulk carries a higher Chern number,

C
=
±
2

.