bluuebunny/crossref_metadata_2025 huggingface dataset:
Effets d’un entraînement à la production de Twoutils sur la réussite de l’accord sujet-verbe chez des élèves de 3e année du primaire
Authors: Alamargot Denis , Louis Jérémy , Morin Marie-France , Aparicio Xavier
Published: August 2022

L’objectif de cette étude est d’examiner dans quelle mesure un entraînement à la production de Twoutils (caractéristiques du dispositif Twictée conçu par des enseignants et mis en place dans de nombreuses classes de primaire) améliore la réussite de l’accord sujet-verbe, chez des élèves de 3e année du primaire, encore novices. Pour ce faire, il a été demandé à 63 élèves de compléter à l’écrit les verbes d’une série de phrases dont le nombre (singulier-pluriel) du nom-sujet et sa distance syntaxique par rapport au verbe (proche-distant) variaient. La comparaison des performances avant, immédiatement après et un mois après trois types d’entraînement (grammatical avec production de Twoutils ; grammatical sans production de Twoutils ; arithmétique - contrôle) montre un effet immédiat des entraînements grammaticaux alors que seul l’entraînement grammatical avec production de Twoutils suscite un maintien des performances un mois après, seulement dans le cas de phrases pour lesquels le nom-sujet est distant du verbe. Ces résultats sont discutés dans le contexte des interventions en classe basées sur les pratiques du métalangage.
Le rapport à la norme orthographique de candidats au concours de professeurs des écoles
Authors: Lepoire-Duc Solveig , Sautot Jean-Pierre
Published: August 2022

Nous analysons un corpus de copies écrites pour un concours de recrutement de professeurs des écoles en France. Notre objectif est d’identifier des compétences déjà présentes ou en devenir dans le contenu des épreuves. L’article présente quelques profils d’enseignants débutant leur formation dans le domaine de la didactique de l’orthographe et plus particulièrement dans le domaine du rapport à la norme.
Ist die therapeutische Mundpflege bei Dysphagiepatient*innen verschwendete Zeit? Ein narrativer Review zu Effekten der Mundpflege auf die Pneumoniehäufigkeit und Ableitung einer Handlungsempfehlung
Authors: Müller Nina , de Beer Carola , Frank Ulrike
Published: August 2022

Aspirationspneumonien sind eine häufige Todesursache bei Dysphagiepatient*innen. In diesem Beitrag wird durch die Evaluation relevanter Studien die Frage untersucht, ob die therapeutische Mundpflege bei Dysphagiepatient*innen zur Verringerung des Pneumonierisikos beitragen kann. Zudem wird auf dieser Grundlage eine Handlungsempfehlung für die Umsetzung der Mundpflege entwickelt.

Die ausgewählten Studien zeigen, dass die Mundpflege einen positiven Effekt auf das Pneumonie-Risiko von Dysphagiepatient*innen hat. Sie sollte auf den Grundsätzen Einfachheit, Sicherheit, Arbeitskräfteentlastung, Wirksamkeit, Universalität, Wirtschaftlichkeit und vollständige Mundpflege aller Teile der Mundhöhle beruhen und nimmt weniger als fünf Minuten täglich ein. Sie bereitet durch die taktile Stimulation auf die anschließende Dysphagie-Therapie vor und ist somit sinnvoll investierte Therapiezeit.
Dendrimers: A Neuroprotective Lead in Alzheimer Disease: A Review on
its Synthetic approach and Applications
Authors: Singh Aditya , Ansari Vaseem A. , Mahmood Tarique , Ahsan Farogh , Wasim Rufaida
Published: August 2022

Alzheimer disease is a neurodegenerative disease that is signified by cognitive
decline, memory loss, and erratic behavior. Dendrimers are a type of polymer
that has a well-defined structure, a high degree of molecular uniformity, and a
low polydispersity which have shown to be effective intracellular drug carriers
for bring down the in numerous cases. The data reported by the clinical trials
and chemical bonds of dendrimers loading and biological properties that may be
used in the bringing out the treatment of nano formulation for Alzheimer
disease. Below-range dendrimers have an unlocked figure, but higher-range
dendrimers have a more globular and dense structure so handling is difficult.
Dendrimers are similar in size to a variety of biological structures; for
example, fifth-generation polyamidoamine (PAMAM) dendrimers are similar in size
and shape to haemoglobin (5.5 nm diameter). Each generation of dendrimer
is described in terms of size, shape, molecular weight, and the number of
surface functional groups, with increasing growth specified in terms of
'generation number.' In contrast, Hawker and Frechet were the
first to report the convergent approach. A stepwise repeating reaction strategy
is used to synthesize dendrimers radically from a central core. The value of
dendrimers as drug carriers is discussed in this paper. The information
presented in this article can provide useful references for further studies on
making dendrimers and applications.
Are Antibiotics Needed in Septorhinoplasty? An Evidence-Based Approach
Authors: Mantelakis Angelos , Argiris Konstantinos , Joshi Anil , D'Souza Alwyn Ray
Published: August 2022

The use of prophylactic antibiotics in the context of septorhinoplasty (SRP) is a frequently debated topic among plastic surgeons. Most surgeons routinely use antibiotics to prevent the dreaded physical and psychological morbidity of postoperative infections, although this practice is controversial. With antimicrobial resistance becoming a global threat, however, optimizing antibiotic prescribing is essential. The current evidence would suggest that the rate of postoperative infection is low and routine antibiotic use is unnecessary in SRP surgery. Rates range from 0.5 to 2% in simple SRP surgery, majority of which are minor nasal infections which respond to oral antibiotics and do not require hospital admission. In cases of complex SRP, defined as revision cases or where grafts or implants have been utilized, infection rates can be much higher with an incidence of 7 to 11%, and as such utilization of antibiotics is reasonable. When considering the regime to be utilized, a single preoperative dose of intravenous antibiotics has the same efficacy in reducing the incident of postoperative infection as a postoperative 7-day course of oral antibiotics. In the authors' practice, all patients receive a single intravenous dose of antibiotics on induction, and in the case of utilization of a graft from a nonnasal site, this is complimented with an oral course of postoperative antibiotics. With this approach, infections rates are at the lowest range of available published literature.
Diagnosis and Management of Cushing's Disease: A Survey of Endocrinologists from the Middle East and North Africa
Authors: Beshyah Salem A. , Almalki Mussa H. , Azzoug Said , Barake Maya , Al Dahmani Khaled M. A. , Chihaoui Melika
Published: August 2022

Background Cushing's disease is the most prevalent cause of endogenous Cushing's syndrome. This study aimed to scope the current clinical practice pattern in managing Cushing's disease by endocrinologists in the Middle Eastern and North African (MENA) region.

Methods A questionnaire dealing with diagnosis, treatment, and follow-up of patients with Cushing's disease was adopted and sent electronically to a convenience sample of endocrinologists from the MENA region.

Results Out of 125 responses received, 88 were eligible for inclusion in the analysis. Most respondents selected the overnight dexamethasone suppression test (ONDST) and 24-hour urinary-free cortisol (UFC) as the best screening tests, 58 (66.7%) and 50 (57.5%) respectively, followed by midnight serum cortisol and midnight salivary cortisol. Measurement of serum adrenocorticotropic hormone (ACTH; 86.2%) and classic high-dose dexamethasone suppression test (40.2%) were selected for localization of the primary lesion. The primary choice of treatment was transsphenoidal pituitary surgery (98.8%). For the recurrence of Cushing's disease, medical therapy was the preferred modality followed by repeated pituitary surgery or bilateral adrenalectomy. In case of treatment failure following the first pituitary surgery and ketoconazole treatment, 36.9% selected pasireotide, while 32.1% chose bilateral adrenalectomy.

Conclusion ONDST and UFC are the two most common tests used to screen an index case with features of hypercortisolism. Pituitary surgery is the primary choice of treatment in Cushing's disease. However, medical treatment by ketoconazole is preferred for recurrent cases. Bilateral adrenalectomy is followed by pasireotide may be chosen in case of treatment failure after pituitary surgery and ketoconazole.
Influence of information attributes on information dissemination in public health emergencies
Authors: Cai Meng , Luo Han , Meng Xiao , Cui Ying , Wang Wei
Published: August 2022

When public health emergencies occur, relevant information containing different topics, sentiments, and emotions spread rapidly on social media. From the cognitive and emotional dimensions, this paper explores the relationship between information attributes and information dissemination behavior. At the same time, the moderating role of the media factor (user influence) and the time factor (life cycle) in information attributes and information transmission is also discussed. The results confirm differences in the spread of posts under different topic types, sentiment types, and emotion types on social media. At the same time, the study also found that posts published by users with a high number of followers and users of a media type are more likely to spread on social media. In addition, the study also found that posts with different information attributes are easier to spread on social media during the outbreak and recurrence periods. The driving effect of life cycles is more obvious, especially for topics of prayer and fact, negative sentiment, emotions of fear, and anger. Relevant findings have specific contributions to the information governance of public opinion, the development of social media theory, and the maintenance of network order, which can further weaken the negative impact of information epidemic in the occurrence of public health emergencies, maintain normal social order, and thus create favorable conditions for the further promotion of global recovery.
CO2 laser heating system for in situ radial x-ray absorption at 16-BM-D at the Advanced Photon Source
Authors: Childs Christian , Smith Dean , Smith G. Alexander , Ellison Paul , Sneed Daniel , Hinton Jasmine , Siska Emily , Pigott Jeffrey S. , Rod Eric , O’Donnell William , Salem Ran , Sturtevant Blake , Scharff R. Jason , Velisavljevic Nenad , Park Changyong , Salamat Ashkan
Published: August 2022

We present a portable CO2 laser heating system for in situ x-ray absorption spectroscopy (XAS) studies at 16-BM-D (High Pressure Collaborative Access Team, Advanced Photon Source, Argonne National Laboratory). Back scattering optical measurements are made possible by the implementation of a Ge beamsplitter. Optical pyrometry is conducted in the near-infrared, and our temperature measurements are free of chromatic aberration due to the implementation of the peak-scaling method [A. Kavner and W. R. Panero, Phys. Earth Planet. Inter. 143–144, 527–539 (2004) and A. Kavner and C. Nugent, Rev. Sci. Instrum. 79, 024902 (2008)] and mode scrambling of the input signal. Laser power stabilization is established using electronic feedback, providing a steady power over second timescales [Childs et al., Rev. Sci. Instrum. 91, 103003 (2020)]—crucial for longer XAS collections. Examples of in situ high pressure–temperature extended x-ray absorption fine structure measurements of ZrO2 are presented to demonstrate this new capability.
On the origin of “patchy” energy conversion in electron diffusion regions
Authors: Genestreti Kevin J. , Li Xiaocan , Liu Yi-Hsin , Burch James L. , Torbert Roy B. , Fuselier Stephen A. , Nakamura Takuma , Giles Barbara L. , Gershman Daniel J. , Ergun Robert E. , Russell Christopher T. , Strangeway Robert J.
Published: August 2022

During magnetic reconnection, field lines interconnect in electron diffusion regions (EDRs). In some EDRs, the reconnection and energy conversion rates are controlled by a steady out-of-plane electric field. In other EDRs, the energy conversion rate J→·E→′ is “patchy,” with electron-scale large-amplitude positive and negative peaks. We investigate 22 EDRs observed by NASA's Magnetospheric Multiscale mission in a wide range of conditions to determine the cause of patchy J→·E→′. The patchiness of the energy conversion is quantified and correlated with seven parameters describing various aspects of the asymptotic inflow regions that affect the structure, stability, and efficiency of reconnection. We find that (1) neither the guide field strength nor the asymmetries in the inflow ion pressure, electron pressure, nor number density are well correlated with the patchiness of the EDR energy conversion; (2) the out-of-plane axes of the 22 EDRs are typically fairly well aligned with the “preferred” axes, which bisect the time-averaged inflow magnetic fields and maximize the reconnection rate; and (3) the time-variability in the upstream magnetic field direction is best correlated with the patchiness of the EDR J→·E→′. A 3D fully kinetic simulation of reconnection with a non-uniform inflow magnetic field is analyzed; the variation in the magnetic field generates secondary X-lines, which develop to maximize the reconnection rate for the time-varying inflow magnetic field. The results suggest that magnetopause reconnection, for which the inflow magnetic field direction is often highly variable, may commonly be patchy in space, at least at the electron scale.
Mode conversion from kinetic Alfvén waves to modified electron acoustic waves
Authors: Shi Run , Liang Jun
Published: August 2022

Possible mode conversion from kinetic Alfvén wave to modified electron acoustic wave is examined based on a multi-fluid model involving two electron populations. The mode conversion transpires when a kinetic Alfvén wave propagates through a transition between a hot-electron-dominant region and a cold-electron-dominant region. It is shown that the mode conversion and the kinetic Alfvén wave reflection depend strongly on the hot electron inertial length, the hot electron temperature, and the perpendicular wavelength. The results suggest that such conversion is ubiquitous whenever a steep gradient of electron temperature exists, for example, in the planetary auroral acceleration regions or at the boundary of the solar corona.
The role of EM wave polarization on radiative heat transfer across a nanoscale gap
Authors: Budaev Bair V. , Bogy David B.
Published: August 2022

This work presents a novel study of radiative heat transfer between closely separated plates based on an extension of Planck’s spectrum of thermal radiations to systems with a steady heat flux. This extension together with electromagnetic wave theory is chosen specifically to avoid the commonly used so-called fluctuation dissipation theory, which is also limited to equilibrium systems. The spectrum of thermal radiation with a heat flux is described by the introduction of an analog of a chemical potential, which creates a bias toward the direction of heat transfer. This is the first comprehensive study of radiative heat transfer based on the generalization of Planck’s spectrum for systems with a heat flux, which eliminates contradictions arising when a heat flux is described in terms of the laws limited to equilibrium systems. The total heat flux is split into fluxes carried by waves with different frequencies, directions of propagation, and polarizations. This simplifies the analysis because due to the stochastic independence, the energy fluxes of such waves are additive, and this also reveals that the heat carrying capacity of radiation with the parallel polarization is significantly higher than that of the perpendicularly polarized radiation. This suggests that the rate of radiative heat transfer may be noticeably increased by the control of the polarization of thermal radiation.
Gelation, clustering, and crowding in the electrical double layer of ionic liquids
Authors: Goodwin Zachary A. H. , McEldrew Michael , Pedro de Souza J. , Bazant Martin Z. , Kornyshev Alexei A.
Published: August 2022

Understanding the bulk and interfacial properties of super-concentrated electrolytes, such as ionic liquids (ILs), has attracted significant attention lately for their promising applications in supercapacitors and batteries. Recently, McEldrew et al. [J. Phys. Chem. B 125, 2677 (2021)] developed a theory for reversible ion associations in bulk ILs, which accounted for the formation of all possible (Cayley tree) clusters and a percolating ionic network (gel). Here, we adopt and develop this approach to understand the associations of ILs in the electrical double layer at electrified interfaces. With increasing charge of the electrode, the theory predicts a transition from a regime dominated by a gelled or clustered state to a crowding regime dominated by free ions. This transition from gelation to crowding is conceptually similar to the overscreening to crowding transition.
Transport properties for neutral C, H, N, O, and Si-containing species and mixtures from the Gordon and McBride thermodynamic database
Authors: Bellas Chatzigeorgis Georgios , Haskins Justin B. , Scoggins James B.
Published: August 2022

Accurate transport properties of non-ionized gas mixtures of C, H, O, N, and Si-containing species at temperatures up to 4000 K are essential in many scientific fields. Mixture transport properties are computed through the solution of linear transport systems, requiring collision integrals as functions of temperature for each binary collision pair in the mixture. Due to the dimensionality of the problem, no such database exists for all the 180 hydrocarbons and silicon species detailed in the nine-coefficient polynomial thermodynamic database of Gordon and McBride, widely used in many applications. This constraint was overcome by using a phenomenological inter-molecular potential energy surface suitable for transport properties, which describes the pair interaction approximated with two fundamental species physical properties, namely the dipole electric polarizability and the number of effective electrons participating in the interaction. These two parameters were calculated with ab initio quantum chemistry calculations, since they were not always available in literature. The studied methodology was verified and validated against other approaches at a species and collision integral level. Transport properties for a variety of equilibrium mixtures, including planetary atmospheres and chemical compositions of thermal protection materials relevant to aerospace applications, were calculated, assessing the predictive capabilities of this new database.
Tree-based machine learning models for prediction of bed elevation around bridge piers
Authors: Rehman Khawar , Wang Yung-Chieh , Waseem Muhammad , Hong Seung Ho
Published: August 2022

Scouring around bridge piers is a highly nonlinear process making its prediction by deterministic and stochastic models challenging. This study explores the application of inferential models for predictions of bed elevations around bridge piers. The objective is to get a generalized machine learning model with an interpretable structure. The historical data comprise a detailed record of streamflow and bed elevations that were captured by sensors installed at the 5th Street Bridge piers over Ocmulgee River at Macon, GA. We investigate the accuracy and efficiency of various tree-based machine learning algorithms, including a single tree as well as homogeneous ensemble models for simultaneous predictions of bed elevation at multiple sensors installed at piers. The ensemble models were based on bagging and boosting techniques. Special attention is given to balancing between overfitting and underfitting without compromise on the model's robustness. Observation of the performance metrics showed that tree-based models have excellent predictive capacity. It was observed that boosting models, including a gradient based regression model, and adaptive boosting outperformed the bagging model. Among all the models investigated in this study, the adaptive boosting method was observed to be most generalizable. The performance of developed models shows the potential of tree-based ensemble models in providing rapid and robust predictions for complex nonlinear fluid flows.
Bidirectional linear inertial impact piezoelectric motor with multimodal resonance
Authors: He Liangguo , Li Kun , Yan Yi , Cheng Ziyang , Xu Lei , Li Xinyu , Ge Xinfang , Shan Zengxiang , Dou Haotian
Published: August 2022

A new multimodal bidirectional linear inertial impact motor with bidirectional motion based on self-clamping control driven by a single-harmonic signal was designed and manufactured. By applying driving signals of different resonant frequencies to the piezoelectric plate of a piezoelectric motor combined with the unique structural design of the motor, the piezoelectric motor has multiple modes and has the ability of two-way movement. First, the overall structure of the motor is introduced, and its working principle and theoretical displacement characteristics are presented through the periodic motion diagram of the piezoelectric motor. Second, the simulation analysis is carried out to determine the working modal of the proposed motor with COMSOL5.2. Finally, a motor prototype is developed, and the accuracy of the working principle and the simulation analysis is verified through experimental tests. When the motor has no load, the driving voltage is 200 Vp–p. The maximum speed when moving to the right reached 3.125 mm/s when the preload is 2 N, and the driving frequency is 96 Hz. The maximum speed when moving to the left reached 4.301 mm/s when the preload is 4 N, and the driving frequency is 148 Hz. In the load capacity test of the motor prototype, the maximum load of the piezoelectric motor prototype moving to the right and left can reach 0.4 and 0.6 N, respectively. Compared with similar inertial impact motors, the proposed motor achieves flexible control of driving and switching of two-way movement conveniently and has a certain driving ability.
A pseudopotential lattice Boltzmann model for simulating mass transfer around a rising bubble under real buoyancy effect
Authors: Guo Guanlong , Zhang Pei , Lei Liang , Galindo-Torres S. A.
Published: August 2022

A pseudopotential multicomponent lattice Boltzmann (LB) model that can account for the real buoyancy effect is proposed to simulate the mass transfer process around a rising bubble. The density profiles at the equilibrium state are determined based on the hydrostatic condition and the zero diffusion flux condition (the balance of chemical potential). Compared with the LB models using effective buoyancy force, the proposed model has three advantages: (1) avoiding the unrealistic distribution of gas components within the bubble due to the upward effective buoyancy force, (2) removing the undesirable diffusion process due to the application of effective buoyancy force, and (3) considering the effect of the pressure gradient on the change of bubble size. In addition, Henry's law, which can be automatically recovered from the multicomponent LB equation, is re-interpreted from the perspective of the balance of chemical potential. Simulation results showed that the diffusion flux non-uniformly distributes over the surface of a rising bubble. The diffusion zone primarily occurs at the top and the lateral side of a rising bubble, whereas the diffusion transport just below the rising bubble is much less significant than its counterpart above the rising bubble. Various bubble shapes and their corresponding diffusion zones have been obtained. Moreover, the correlation between the Sherwood number and the Peclet number derived from the simulation results is consistent with those from previous numerical results. Thus, the proposed LB model is capable of conducting a quantitative analysis of the mass transfer around a rising bubble.
Three-dimensional effects induced by depth variation in a differentially heated cavity
Authors: Gers R. , Skurtys O. , Thiers N. , Moreau F. , Saury D.
Published: August 2022

This work investigates a natural convection flow occurring in a differentially heated cavity. The main purpose of this paper is to analyze the influence of the cavity depth variation on heat transfers and flow dynamics. Three-dimensional numerical simulations are conducted. The working fluid is air, the vertical aspect ratio (cavity height over width) is equal to 4, and the Rayleigh Number is equal to 108. The impact of the rear and front boundary conditions on the flow topology is highlighted. When the cavity depth increases, three-dimensional effects are encountered that enhance local heat transfer at the isothermal walls. In particular, for horizontal aspect ratio (cavity depth over width) greater than 1, an alternation of local maximum and minimum Nusselt numbers can be observed along the y-direction toward the center of the wall in the lower half part of the isothermal wall, which are similar to a wave-like behavior. It is shown that they are due to vortex structures generated by a Görtler instability. The depth variation increases the emergence of those structures, but paradoxically several characteristics of both flow and heat transfer, such as the depth-averaged shear stress or the Nusselt numbers, tend to the two-dimensional case value as the cavity gets deeper.
Drag reduction by flapping a flexible filament behind a stationary cylinder
Authors: Mao Qian , Liu Yingzheng , Sung Hyung Jin
Published: August 2022

The hydrodynamic mechanism of drag reduction by flapping a flexible filament behind a stationary cylinder was explored using the penalty immersed boundary method. The effects of the filament length, bending rigidity, pitching amplitude, and frequency on drag reduction were systematically examined. We analyzed the underlying mechanism of drag reduction in detail by examining flapping modes, wake patterns, pressure distributions, and flapping dynamics of the flapping filament. The flapping motion of the flexible filament is determined by the combined effect of forcing parameters and the surrounding flow. Three distinct flapping modes are observed when the aforementioned parameters are varied: an oscillation mode, an undulation mode, and a vortex-dominated mode. The oscillation and undulation modes are more beneficial to drag reduction than the vortex-dominated mode. In the oscillation mode, drag reduction is mainly realized by the high thrust generated by the filament overwhelming the increased form drag of the cylinder caused by the trailing edge vortex. A flexible filament flapping in the oscillation mode generates thrust more efficiently. In the undulation mode, a long filament reduces the form drag of the cylinder and generates relatively low thrust, showing a similar drag reduction as a short oscillating filament. In the vortex-dominated mode, the thrust of the filament is very low because of the weakened trailing edge vortex, yielding a weakened drag reduction effect.
Machine learning changes the rules for flux limiters
Authors: Nguyen-Fotiadis Nga , McKerns Michael , Sornborger Andrew
Published: August 2022

Learning to integrate non-linear equations from highly resolved direct numerical simulations has seen recent interest for reducing the computational load for fluid simulations. Here, we focus on determining a flux-limiter for shock capturing methods. Focusing on flux limiters provides a specific plug-and-play component for existing numerical methods. Since their introduction, an array of flux limiters has been designed. Using the coarse-grained Burgers' equation, we show that flux-limiters may be rank-ordered in terms of their log-error relative to high-resolution data. We then develop a theory to find an optimal flux-limiter and present flux-limiters that outperform others tested for integrating Burgers' equation on lattices with 2×, 3×, 4×, and 8× coarse-grainings. We train a continuous piecewise linear limiter by minimizing the mean-squared misfit to six-grid point segments of high-resolution data, averaged over all segments. While flux limiters are generally designed to have an output of ϕ(r)=1 at a flux ratio of r = 1, our limiters are not bound by this rule and yet produce a smaller error than standard limiters. We find that our machine learned limiters have distinctive features that may provide new rules-of-thumb for the development of improved limiters. Additionally, we use our theory to learn flux-limiters that outperform standard limiters across a range of values (as opposed to at a specific fixed value) of coarse-graining, number of discretized bins, and diffusion parameter. This demonstrates the ability to produce flux limiters that should be more broadly useful than standard limiters for general applications.
Ohmic co-doped GaN/InGaN tunneling diode grown by MOCVD
Authors: Hagar B. G. , Abdelhamid M. , Routh E. L. , Colter P. C. , Bedair S. M.
Published: August 2022

Tunnel junctions (TJs) have recently been proposed as a solution for several III-nitride current problems and to enhance new structures. Reported III-nitride TJs grown by metalorganic chemical vapor deposition (MOCVD) resulted in backward diodes with rectifying behavior in forward bias, even with Mg and Si doping in 1020 cm−3. This behavior limits applications in several device structures. We report a TJ structure based on p+In0.15Ga0.85N/n+In0.05Ga0.95N, where the n-side of the junction is co-doped with Si and Mg and with electron and hole concentrations in the mid-1019 cm−3 for both the n and p dopants. Co-doping creates deep levels within the bandgap that enhances tunneling under forward biased conditions. The TJ structure was investigated on both GaN substrates and InGaN templates to study the impact of strain on the TJ I–V characteristics. The resulting TJ I–V and resistivities reported indicate the potential for this TJ approach in several device structures based on III-nitrides. We are not aware of any previous MOCVD grown TJs that show Ohmic performance in both forward and reverse biases.
Vitrification of bovine germinal vesicle oocytes significantly decreased the methylation level of their
Authors: Zhang Peipei , Yang Sha , Zhang Hang , Hao Haisheng , Du Weihua , Wang Jingjing , Hao Tong , Zhu Huabin , Umer Saqib , Zhao Xueming
Published: August 2022

Context The vitrification of oocytes is important for the conservation of animals, and the effect of vitrification on methylation patterns of bovine oocytes remains unclear. Aims This article aims to investigate the effect of vitrification on the DNA methylation patterns on vitrified GV oocytes and their in vitro derived MII oocytes. Methods 5-MeC staining and single-cell whole genome bisulphite sequencing (SC-WGBS) were utilised to analyse fresh GV oocytes (F_GV group), MII oocytes (F_MII group), vitrified GV oocytes (V_GV group) and their in vitro derived MII oocytes (V_MII group). Key results Results of both 5-MeC staining and SC-WGBS showed that no significant difference was found between the F_GV group and the V_GV group, while the methylation level of the V_MII group was significantly lower than that of the F_MII group. Moreover, supplementation of 2 μM resveratrol (Res) in IVM medium significantly improved maturation and development ability of vitrified GV oocytes by restoring their DNA methylation levels. Conclusion In conclusion, vitrification of bovine GV oocytes significantly decreased the DNA methylation level of their in vitro derived MII oocytes, and 2 μM Res improved their development ability by restoring DNA methylation level. Implications Our results provide an efficient approach to improve the maturation and fertilisation ability of vitrified GV oocytes.
Seizure-induced strengthening of a recurrent excitatory circuit in the dentate gyrus is proconvulsant
Authors: Nasrallah Kaoutsar , Frechou M. Agustina , Yoon Young J. , Persaud Subrina , Gonçalves J. Tiago , Castillo Pablo E.
Published: August 2022

Epilepsy is a devastating brain disorder for which effective treatments are very limited. There is growing interest in early intervention, which requires a better mechanistic understanding of the early stages of this disorder. While diverse brain insults can lead to epileptic activity, a common cellular mechanism relies on uncontrolled recurrent excitatory activity. In the dentate gyrus, excitatory mossy cells (MCs) project extensively onto granule cells (GCs) throughout the hippocampus, thus establishing a recurrent MC-GC-MC excitatory loop. MCs are implicated in temporal lobe epilepsy, a common form of epilepsy, but their role during initial seizures (i.e., before the characteristic MC loss that occurs in late stages) is unclear. Here, we show that initial seizures acutely induced with an intraperitoneal kainic acid (KA) injection in adult mice, a well-established model that leads to experimental epilepsy, not only increased MC and GC activity in vivo but also triggered a brain-derived neurotrophic factor (BDNF)–dependent long-term potentiation (LTP) at MC-GC excitatory synapses. Moreover, in vivo induction of MC-GC LTP using MC-selective optogenetic stimulation worsened KA-induced seizures. Conversely,Bdnfgenetic removal from GCs, which abolishes LTP, and selective MC silencing were both anticonvulsant. Thus, initial seizures are associated with MC-GC synaptic strengthening, which may promote later epileptic activity. Our findings reveal a potential mechanism of epileptogenesis that may help in developing therapeutic strategies for early intervention.
Microenvironmental sensing by fibroblasts controls macrophage population size
Authors: Zhou Xu , Franklin Ruth A. , Adler Miri , Carter Trevor S. , Condiff Emily , Adams Taylor S. , Pope Scott D. , Philip Naomi H. , Meizlish Matthew L. , Kaminski Naftali , Medzhitov Ruslan
Published: August 2022

Animal tissues comprise diverse cell types. However, the mechanisms controlling the number of each cell type within tissue compartments remain poorly understood. Here, we report that different cell types utilize distinct strategies to control population numbers. Proliferation of fibroblasts, stromal cells important for tissue integrity, is limited by space availability. In contrast, proliferation of macrophages, innate immune cells involved in defense, repair, and homeostasis, is constrained by growth factor availability. Examination of density-dependent gene expression in fibroblasts revealed that Hippo and TGF-β target genes are both regulated by cell density. We found YAP1, the transcriptional coactivator of the Hippo signaling pathway, directly regulates expression of
Csf1
, the lineage-specific growth factor for macrophages, through an enhancer of
Csf1
that is specifically active in fibroblasts. Activation of YAP1 in fibroblasts elevates
Csf1
expression and is sufficient to increase the number of macrophages at steady state. Our data also suggest that expression programs in fibroblasts that change with density may result from sensing of mechanical force through actin-dependent mechanisms. Altogether, we demonstrate that two different modes of population control are connected and coordinated to regulate cell numbers of distinct cell types. Sensing of the tissue environment may serve as a general strategy to control tissue composition.
Validation of app-based hearing assessment (H3 hearing test) through smart phone
Authors: Katyayan Adri , Katyayan Angira , Rajput Arti , Chandra Manish , Verma Veerendra , Mishra Anupam
Published: August 2022

Objective

To promote tele-audiology, the smartphone online applications (APP) for assessment of hearing function need to be validated. We present our preliminary report of one such APP that we adapted during the active COVID phase of 2021.

Methodology

A total of 44 patients underwent both pure tone audiometry (PTA) and APP-based hearing assessment. The air conduction thresholds at 500 Hz, 1000 Hz, 2000 Hz, 3000 Hz, 4000 Hz, 6000 Hz and 8000 Hz were noted.

Results

A significant correlation was seen between the thresholds and paired differences. However, air-conduction (AC) thresholds of either PTA or APP were shown to overshoot each other and right side values were more consistent.

Conclusions

While suggestions have been made to overcome these inconsistencies, the APP-based hearing assessment is likely to improve tele-audiology as relevant modifications by the manufacturer are incorporated to improve its efficacy.
High curie temperature, large magnetocrystalline anisotropy energy and piezoelectricity in 2D tetrahedral VXCl (X = Te, Se, S) & VMSe2 (M = Al, Ga, In)
Authors: Wang Guang , Li Jia , Liu Ze , Jin Yuming , Zhang Qian
Published: August 2022

The ferromagnetic semiconducting materials with tetrahedral coordination structure have lower crystal field repulsion energy and variable structure, which would be beneficial to achieve high Curie temperature and multiferroics. Based on density functional theory calculations, the monolayer VXCl (X = Te, Se, S) and VMSe2 (M = Al, Ga, In) with tetrahedral coordination structure are predicted to be ferromagnetic semiconductors with high T
c and large magnetocrystalline anisotropy. With the monolayer BiCrSe3 (T
c above 400 K) being treated as the representative sample of octahedral materials, we reveal the disadvantages of two different coordination structures in 2D condition, namely tetrahedral and octahedral coordination, and find that modulation of bond angles is effective and feasible to enhance the magnetic exchange of tetrahedral materials. Moreover, the two series of predicted materials have favorable piezoelectric properties. Our work paves a feasible route for finding new low-dimensional ferromagnetic materials with excellent properties.
n-type SnS2thin films spray-coated from transparent molecular ink as a non-toxic buffer layer for solar photovoltaics
Authors: Tair Sabrina , Ghediya Prashant R , Ech-Chergui Abdelkader Nebatti , Guezzoul M’hamed , Mukherjee Sanat Kumar , Driss-Khodja Kouider , Singh Rajan , Ray Jaymin , Amrani Bouhalouane
Published: August 2022

This paper reports the effect of solvent evaporation temperature on spray-coated tin disulfide (SnS2) thin films from molecular ink. Thiourea and tin chloride were the key chemical reagents used for the synthesis of SnS2transparent ink under atmospheric conditions. The structural and compositional properties of SnS2thin films revealed formation of pristine hexagonal SnS2. The films are smooth, homogeneous resulting in band gaps ranging from 2 to 2.22 eV suited for a Cd-free alternative buffer layer for Cu-based multicomponent solar cells. Thermoelectric power measurement showed that tin disulfide films exhibit n-type conductivity. Activation energy estimated from temperature variation of electrical conductivity measurement varied from 40 to 90 mV. Our results suggest that ink-processed SnS2can be used as a potential alternative for opto-electronic devices such as thin film solar cell and photodetector devices.
Towards predicting ECoG-BCI performance: assessing the potential of scalp-EEG
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Authors: Fahimi Hnazaee Mansoureh , Verwoert Maxime , Freudenburg Zachary V , van der Salm Sandra M A , Aarnoutse Erik J , Leinders Sacha , Van Hulle Marc M , Ramsey Nick F , Vansteensel Mariska J
Published: August 2022

Objective. Implanted brain-computer interfaces (BCIs) employ neural signals to control a computer and may offer an alternative communication channel for people with locked-in syndrome (LIS). Promising results have been obtained using signals from the sensorimotor (SM) area. However, in earlier work on home-use of an electrocorticography (ECoG)-based BCI by people with LIS, we detected differences in ECoG-BCI performance, which were related to differences in the modulation of low frequency band (LFB) power in the SM area. For future clinical implementation of ECoG-BCIs, it will be crucial to determine whether reliable performance can be predicted before electrode implantation. To assess if non-invasive scalp-electroencephalography (EEG) could serve such prediction, we here investigated if EEG can detect the characteristics observed in the LFB modulation of ECoG signals. Approach. We included three participants with LIS of the earlier study, and a control group of 20 healthy participants. All participants performed a Rest task, and a Movement task involving actual (healthy) or attempted (LIS) hand movements, while their EEG signals were recorded. Main results. Data of the Rest task was used to determine signal-to-noise ratio, which showed a similar range for LIS and healthy participants. Using data of the Movement task, we selected seven EEG electrodes that showed a consistent movement-related decrease in beta power (13–30 Hz) across healthy participants. Within the EEG recordings of this subset of electrodes of two LIS participants, we recognized the phenomena reported earlier for the LFB in their ECoG recordings. Specifically, strong movement-related beta band suppression was observed in one, but not the other, LIS participant, and movement-related alpha band (8–12 Hz) suppression was practically absent in both. Results of the third LIS participant were inconclusive due to technical issues with the EEG recordings. Significance. Together, these findings support a potential role for scalp EEG in the presurgical assessment of ECoG-BCI candidates.
Passivation of perovskite layer surface states with pyridine in flexible and printed perovskite solar cells
Authors: Kakimov Alibek G , Yerlanuly Yerassyl , Akhanuly Assylan , Dossayev Iliyas T , Shalenov Erik O , Sadirkhanov Zhandos T , Dzhumagulova Karlygash N , Ng Annie , Jumabekov Askhat N
Published: August 2022

Perovskite solar cells (PSCs), prepared by using solution-processed printing techniques, gained much attention over the past few years and a considerable progress has been achieved in improving the power conversion efficiencies of these devices. Nevertheless, there are still some advancements that can be implemented, especially in terms of passivation of surface defects in the perovskite photoactive layer. Passivation can afford considerable reduction in surface recombination of charge carriers in the photoactive layer and help to obtain devices with better performance. In this work, poly(3-hexylthiophene-2,5-diyl)-based inks with small amount of pyridine as an additive are used to deposit the hole transport layer and simultaneously passivate the surface defects of the perovskite layer in flexible and printed PSCs. The devices are fabricated on flexible conductive plastic substrates using a slot-die coating method. It is found that 2.5 wt.% pyridine-containing inks for preparing hole transport layer have a positive effect on the performance of resulting PSCs. On average, around 13% improvement in the power conversion efficiency is observed for the devices with passivation as opposed to the reference devices without passivation. The effect of pyridine passivation on the structural and electronic properties of the perovskite layer on a flexible substrate is studied using experimental and analytical techniques, whereas the computer simulation methods are employed to rule out the possible mechanisms for the performance improvements in the devices with passivation. The approach presented here can be useful for developing simplified protocols for printing of flexible PSCs with the passivated perovskite layer and improved device efficiency.
Simulation and analysis of mechanical properties of cold-formed lock-seam of truss rods for on-orbit construction
Authors: Yang Xingwen , Han Jingtao , Liu Jing , Liang Jinchao
Published: August 2022

In this paper, a new process of spiral cold forming of truss rods for on-orbit construction is proposed. The influence of the width of the lock-seam overlapping region, stirp thickness and lock-seam buckle structure types on the mechanical properties of the rods’ lock-seam was investigated by using a method combining of single tensile experiment and numerical simulation. The results show that for the flat buckle samples with the stirp thickness of 0.3 mm, with the increase of the width of overlapping region of the lock-seam, the maximum occlusal force and maximum occlusal strength of the lock-seam are monotonically decreasing. Although the simulated maximum occlusal force is slightly higher than the actual maximum occlusal force, the simulation results show reasonable agreement with the experimental values. In the simulation, with the increase of the stirp thickness, the maximum occlusal force of the flat buckle has a linear increase, while the maximum occlusal strength increases slightly. Compared with the flat buckle type, when the lock-seam is designed as a pressed rib buckle type, the overall mechanical properties of the lock-seam are improved by 80%. It is more effective to improve the mechanical properties of the rods’ lock-seam by changing the buckle type.
Collisions and collisional transport—II. Fully-ionized plasmas—Unmagnetized
Authors: Bers Abraham
Published: August 2022

This chapter expands the discussion of collisional scattering of particles by examining collisional relaxation rates and some collisional transport characteristics in unmagnetized, fully-ionized plasmas. The material is presented here so that students can develop qualitative and quantitative knowledge about the effects of collisions and some important collisional transport phenomena in such plasmas. This is particularly relevant at this stage, since collective modes of waves and instabilities in high-temperature plasmas are conveniently studied, in first-approximation, from “collisionless” models of plasma dynamics. To gain some insight into the dynamics of elastic Coulomb collisional processes—the binary elastic collision between two charged particles interacting through their own electric field—the chapter considers the evolution of a tenuous beam of “test” particles at a given velocity, colliding with a Maxwellian distribution of “field” particles, of density and temperature, which is much more numerous and remains (at least initially) essentially unchanged.
Prediction of gene co-expression from chromatin contacts with graph attention network
Authors: Zhang Ke , Wang Chenxi , Sun Liping , Zheng Jie
Published: August 2022

Motivation

The technology of high-throughput chromatin conformation capture (Hi-C) allows genome-wide measurement of chromatin interactions. Several studies have shown statistically significant relationships between gene–gene spatial contacts and their co-expression. It is desirable to uncover epigenetic mechanisms of transcriptional regulation behind such relationships using computational modeling. Existing methods for predicting gene co-expression from Hi-C data use manual feature engineering or unsupervised learning, which either limits the prediction accuracy or lacks interpretability.

Results

To address these issues, we propose HiCoEx (Hi-C predicts gene co-expression), a novel end-to-end framework for explainable prediction of gene co-expression from Hi-C data based on graph neural network. We apply graph attention mechanism to a gene contact network inferred from Hi-C data to distinguish the importance among different neighboring genes of each gene, and learn the gene representation to predict co-expression in a supervised and task-specific manner. Then, from the trained model, we extract the learned gene embeddings as a model interpretation to distill biological insights. Experimental results show that HiCoEx can learn gene representation from 3D genomics signals automatically to improve prediction accuracy, and make the black box model explainable by capturing some biologically meaningful patterns, e.g., in a gene contact network, the common neighbors of two central genes might contribute to the co-expression of the two central genes through sharing enhancers.

Availability and implementation

The source code is freely available at https://github.com/JieZheng-ShanghaiTech/HiCoEx.

Supplementary information

Supplementary data are available at Bioinformatics online.