bluuebunny/crossref_metadata_2025 huggingface dataset:
Deficiency of the minor spliceosome component U4atac snRNA secondarily results in ciliary defects in human and zebrafish
Authors: Khatri Deepak , Putoux Audrey , Cologne Audric , Kaltenbach Sophie , Besson Alicia , Bertiaux Eloïse , Guguin Justine , Fendler Adèle , Dupont Marie A. , Benoit-Pilven Clara , Qebibo Leila , Ahmed-Elie Samira , Audebert-Bellanger Séverine , Blanc Pierre , Rambaud Thomas , Castelle Martin , Cornen Gaëlle , Grotto Sarah , Guët Agnès , Guibaud Laurent , Michot Caroline , Odent Sylvie , Ruaud Lyse , Sacaze Elise , Hamel Virginie , Bordonné Rémy , Leutenegger Anne-Louise , Edery Patrick , Burglen Lydie , Attié-Bitach Tania , Mazoyer Sylvie , Delous Marion
Published: February 2023

In the human genome, about 750 genes contain one intron excised by the minor spliceosome. This spliceosome comprises its own set of snRNAs, among which U4atac. Its noncoding gene,
RNU4ATAC
, has been found mutated in Taybi-Linder (TALS/microcephalic osteodysplastic primordial dwarfism type 1), Roifman (RFMN), and Lowry-Wood (LWS) syndromes. These rare developmental disorders, whose physiopathological mechanisms remain unsolved, associate ante- and post-natal growth retardation, microcephaly, skeletal dysplasia, intellectual disability, retinal dystrophy, and immunodeficiency. Here, we report bi-allelic
RNU4ATAC
mutations in five patients presenting with traits suggestive of the Joubert syndrome (JBTS), a well-characterized ciliopathy. These patients also present with traits typical of TALS/RFMN/LWS, thus widening the clinical spectrum of
RNU4ATAC
-associated disorders and indicating ciliary dysfunction as a mechanism downstream of minor splicing defects. Intriguingly, all five patients carry the n.16G>A mutation, in the Stem II domain, either at the homozygous or compound heterozygous state. A gene ontology term enrichment analysis on minor intron-containing genes reveals that the cilium assembly process is over-represented, with no less than 86 cilium-related genes containing at least one minor intron, among which there are 23 ciliopathy-related genes. The link between
RNU4ATAC
mutations and ciliopathy traits is supported by alterations of primary cilium function in TALS and JBTS-like patient fibroblasts, as well as by
u4atac
zebrafish model, which exhibits ciliopathy-related phenotypes and ciliary defects. These phenotypes could be rescued by WT but not by pathogenic variants-carrying human U4atac. Altogether, our data indicate that alteration of cilium biogenesis is part of the physiopathological mechanisms of TALS/RFMN/LWS, secondarily to defects of minor intron splicing.
Deportations and departures: Undocumented Mexican immigrants’ return migration during three presidential administrations
Authors: Sohn Heeju , Pebley Anne R. , Landrian Gonzalez Amanda , Goldman Noreen
Published: February 2023

This study examines changes in the sociodemographic patterns of deportation and voluntary return of undocumented immigrants from the United States to Mexico during three US presidential administrations (2001 to 2019) with different immigration policies. Most previous studies examining these migration flows for the United States as a whole have relied exclusively on counts of deportees and returnees, thereby ignoring changes over the past 20 y in the characteristics of the undocumented population itself, i.e., the population at risk of deportation or voluntary return. We estimate Poisson models based on two data sources that permit us to compare changes in the sex, age, education, and marital status distributions of both deportees and voluntary return migrants with the corresponding changes in the undocumented population during the Bush, Obama, and Trump administrations: the Migration Survey on the Borders of Mexico-North (Encuesta sobre Migración en las Fronteras de México-Norte) for counts of deportees and voluntary return migrants and the Current Population Survey’s Annual Social and Economic Supplement for estimated counts of the undocumented population living in the United States. We find that whereas disparities by sociodemographic characteristics in the likelihood of deportation generally increased beginning in Obama’s first term, sociodemographic disparities in the likelihood of voluntary return generally decreased over this period. Despite heightened antiimmigrant rhetoric during the Trump administration, the changes in deportation and voluntary return migration to Mexico among the undocumented during Trump’s term were part of a trend that began early in the Obama administration.
Liver X receptor controls follicular helper T cell differentiation via repression of TCF-1
Authors: Kim Jiyeon , Lee Haeseung , Lee Jeong-Eun , Choi Garam , Chung Hayeon , Kim Daehong , Park Min Jung , Gye Yong Seok , Shin Kwang-Soo , Kang Chang-Yuil , Kwok Seung-Ki , Chung Yeonseok
Published: February 2023

Liver X receptor (LXR) is a critical regulator of cholesterol homeostasis that inhibits T cell receptor (TCR)-induced proliferation by altering intracellular sterol metabolism. However, the mechanisms by which LXR regulates helper T cell subset differentiation remain unclear. Here, we demonstrate that LXR is a crucial negative regulator of follicular helper T (Tfh) cells in vivo. Both mixed bone marrow chimera and antigen-specific T cell adoptive cotransfer studies show a specific increase in Tfh cells among LXRβ-deficient CD4
+
T cell population in response to immunization and lymphocytic choriomeningitis mammarenavirus (LCMV) infection. Mechanistically, LXRβ-deficient Tfh cells express augmented levels of T cell factor 1 (TCF-1) but comparable levels of Bcl6, CXCR5, and PD-1 in comparison with those of LXRβ-sufficient Tfh cells. Loss of LXRβ confers inactivation of GSK3β induced by either AKT/Extracellular signal-regulated kinase (ERK) activation or Wnt/β-catenin pathway, leading to elevated TCF-1 expression in CD4
+
T cells. Conversely, ligation of LXR represses TCF-1 expression and Tfh cell differentiation in both murine and human CD4
+
T cells. LXR agonist significantly diminishes Tfh cells and the levels of antigen-specific IgG upon immunization. These findings unveil a cell-intrinsic regulatory function of LXR in Tfh cell differentiation via the GSK3β-TCF1 pathway, which may serve as a promising target for pharmacological intervention in Tfh-mediated diseases.
Encoding of 3D physical dimensions by face-selective cortical neurons
Authors: Khandhadia Amit P. , Murphy Aidan P. , Koyano Kenji W. , Esch Elena M. , Leopold David A.
Published: February 2023

Neurons throughout the primate inferior temporal (IT) cortex respond selectively to visual images of faces and other complex objects. The response magnitude of neurons to a given image often depends on the size at which the image is presented, usually on a flat display at a fixed distance. While such size sensitivity might simply reflect the angular subtense of retinal image stimulation in degrees, one unexplored possibility is that it tracks the real-world geometry of physical objects, such as their size and distance to the observer in centimeters. This distinction bears fundamentally on the nature of object representation in IT and on the scope of visual operations supported by the ventral visual pathway. To address this question, we assessed the response dependency of neurons in the macaque anterior fundus (AF) face patch to the angular versus physical size of faces. We employed a macaque avatar to stereoscopically render three-dimensional (3D) photorealistic faces at multiple sizes and distances, including a subset of size/distance combinations designed to cast the same size retinal image projection. We found that most AF neurons were modulated principally by the 3D physical size of the face rather than its two-dimensional (2D) angular size on the retina. Further, most neurons responded strongest to extremely large and small faces, rather than to those of normal size. Together, these findings reveal a graded encoding of physical size among face patch neurons, providing evidence that category-selective regions of the primate ventral visual pathway participate in a geometric analysis of real-world objects.
Epigenetic-based age acceleration in a representative sample of older Americans: Associations with aging-related morbidity and mortality
Authors: Faul Jessica D. , Kim Jung Ki , Levine Morgan E. , Thyagarajan Bharat , Weir David R. , Crimmins Eileen M.
Published: February 2023

Biomarkers developed from DNA methylation (DNAm) data are of growing interest as predictors of health outcomes and mortality in older populations. However, it is unknown how epigenetic aging fits within the context of known socioeconomic and behavioral associations with aging-related health outcomes in a large, population-based, and diverse sample. This study uses data from a representative, panel study of US older adults to examine the relationship between DNAm-based age acceleration measures in the prediction of cross-sectional and longitudinal health outcomes and mortality. We examine whether recent improvements to these scores, using principal component (PC)-based measures designed to remove some of the technical noise and unreliability in measurement, improve the predictive capability of these measures. We also examine how well DNAm-based measures perform against well-known predictors of health outcomes such as demographics, SES, and health behaviors. In our sample, age acceleration calculated using “second and third generation clocks,” PhenoAge, GrimAge, and DunedinPACE, is consistently a significant predictor of health outcomes including cross-sectional cognitive dysfunction, functional limitations and chronic conditions assessed 2 y after DNAm measurement, and 4-y mortality. PC-based epigenetic age acceleration measures do not significantly change the relationship of DNAm-based age acceleration measures to health outcomes or mortality compared to earlier versions of these measures. While the usefulness of DNAm-based age acceleration as a predictor of later life health outcomes is quite clear, other factors such as demographics, SES, mental health, and health behaviors remain equally, if not more robust, predictors of later life outcomes.
Enhancing the activity of Pd ensembles on graphene by manipulating coordination environment
Authors: Huang Dahong , Rigby Kali , Chen Weirui , Wu Xuanhao , Niu Junfeng , Stavitski Eli , Kim Jae-Hong
Published: February 2023

Atomic dispersion of metal catalysts on a substrate accounts for the increased atomic efficiency of single-atom catalysts (SACs) in various catalytic schemes compared to the nanoparticle counterparts. However, lacking neighboring metal sites has been shown to deteriorate the catalytic performance of SACs in a few industrially important reactions, such as dehalogenation, CO oxidation, and hydrogenation. Metal ensemble catalysts (M
n
), an extended concept to SACs, have emerged as a promising alternative to overcome such limitation. Inspired by the fact that the performance of fully isolated SACs can be enhanced by tailoring their coordination environment (CE), we here evaluate whether the CE of M
n
can also be manipulated in order to enhance their catalytic activity. We synthesized a set of Pd ensembles (Pd
n
) on doped graphene supports (Pd
n
/X-graphene where X = O, S, B, and N). We found that introducing S and N onto oxidized graphene modifies the first shell of Pd
n
converting Pd–O to Pd–S and Pd–N, respectively. We further found that the B dopant significantly affected the electronic structure of Pd
n
by serving as an electron donor in the second shell. We examined the performance of Pd
n
/X-graphene toward selective reductive catalysis, such as bromate reduction, brominated organic hydrogenation, and aqueous-phase CO
2
reduction. We observed that Pd
n
/N-graphene exhibited superior performance by lowering the activation energy of the rate-limiting step, i.e., H
2
dissociation into atomic hydrogen. The results collectively suggest controlling the CE of SACs in an ensemble configuration is a viable strategy to optimize and enhance their catalytic performance.
EphB2-dependent prefrontal cortex activation promotes long-range social approach and partner responsiveness
Authors: He Li-Na , Chen Si , Yang Qi , Wu Zheng , Lao Zheng-Kai , Tang Chang-Fei , Song Jiao-Jiao , Liu Xian-Dong , Lu Jiangteng , Xu Xiao-Hong , Chen Jin-Jin , Xu Tian-Le , Sun Suya , Xu Nan-Jie
Published: February 2023

Social behavior starts with dynamic approach prior to the final consummation. The flexible processes ensure mutual feedback across social brains to transmit signals. However, how the brain responds to the initial social stimuli precisely to elicit timed behaviors remains elusive. Here, by using real-time calcium recording, we identify the abnormalities of EphB2 mutant with autism-associated Q858X mutation in processing long-range approach and accurate activity of prefrontal cortex (dmPFC). The EphB2-dependent dmPFC activation precedes the behavioral onset and is actively associated with subsequent social action with the partner. Furthermore, we find that partner dmPFC activity is responsive coordinately to the approaching WT mouse rather than Q858X mutant mouse, and the social defects caused by the mutation are rescued by synchro-optogenetic activation in dmPFC of paired social partners. These results thus reveal that EphB2 sustains neuronal activation in the dmPFC that is essential for the proactive modulation of social approach to initial social interaction.
Type III interferon drives thymic B cell activation and regulatory T cell generation
Authors: Martinez Ryan J. , Breed Elise R. , Worota Yosan , Ashby Katherine M. , Vobořil Matouš , Mathes Tailor , Salgado Oscar C. , O’Connor Christine H. , Kotenko Sergei V. , Hogquist Kristin A.
Published: February 2023

The activation of thymic B cells is critical for their licensing as antigen presenting cells and resulting ability to mediate T cell central tolerance. The processes leading to licensing are still not fully understood. By comparing thymic B cells to activated Peyer’s patch B cells at steady state, we found that thymic B cell activation starts during the neonatal period and is characterized by TCR/CD40-dependent activation, followed by immunoglobulin class switch recombination (CSR) without forming germinal centers. Transcriptional analysis also demonstrated a strong interferon signature, which was not apparent in the periphery. Thymic B cell activation and CSR were primarily dependent on type III IFN signaling, and loss of type III IFN receptor in thymic B cells resulted in reduced thymocyte regulatory T cell (T
reg
) development. Finally, from TCR deep sequencing, we estimate that licensed B cells induce development of a substantial fraction of the T
reg
cell repertoire. Together, these findings reveal the importance of steady-state type III IFN in generating licensed thymic B cells that induce T cell tolerance to activated B cells.
Combined wave emission system based on dual resonance method for airborne transient electromagnetic detection
Authors: Zhang Xinhao , Pang Xiaoyu , Liu Weiyu , Yu Shengbao , Zhang Zhaolin
Published: February 2023

To improve the detection efficiency of airborne transient electromagnetic method (ATEM) and reduce the times of flight experiments, a dual resonance-based combined wave emission circuit is proposed in this paper, which realizes the combined emission of half-sine wave and triangular wave through the selection of different resonant branches. Based on the operating principle of the proposed emission circuit, the model of second-order resistor-inductor-capacitor equivalent circuit is established. Then, the generation process of the combined wave is analyzed, and the segmentation control method is proposed. Finally, the feasibility and effectiveness of the proposed combined wave emission system are verified by simulation model building and prototype testing, and the results show that the emission current has good quality and high stability. Compared with the traditional emission of single wave current, the combined wave current has the advantages of large magnetic moment of half-sine wave and rich high-frequency components of triangular narrow pulse, which can effectively expand the detection range and improve the measurement efficiency of ATEM.
Transcranial 3D ultrasound localization microscopy using a large element matrix array with a multi-lens diffracting layer: an in vitro study
Authors: Favre Hugues , Pernot Mathieu , Tanter Mickael , Papadacci Clément
Published: February 2023

Objective. Early diagnosis and acute knowledge of cerebral disease require to map the microflows of the whole brain. Recently, ultrasound localization microscopy (ULM) was applied to map and quantify blood microflows in 2D in the brain of adult patients down to the micron scale. Whole brain 3D clinical ULM remains challenging due to the transcranial energy loss which reduces significantly the imaging sensitivity. Approach. Large aperture probes with a large surface can increase both the field of view and sensitivity. However, a large active surface implies thousands of acoustic elements, which limits clinical translation. In a previous simulation study, we developed a new probe concept combining a limited number of elements and a large aperture. It is based on large elements, to increase sensitivity, and a multi-lens diffracting layer to improve the focusing quality. In this study, a 16 elements prototype, driven at 1 MHz frequency, was made and in vitro experiments were performed to validate the imaging capabilities of this new probe concept. Main results. First, pressure fields emitted from a large single transducer element without and with diverging lens were compared. Low directivity was measured for the large element with the diverging lens while maintaining high transmit pressure. The focusing quality of 4 × 3cm matrix arrays of 16 elements without/with lenses were compared. In vitro experiments in a water tank and through a human skull were achieved to localize and track microbubbles in tubes. Significance. ULM was achieved demonstrating the strong potential of multi-lens diffracting layer to enable microcirculation assessment over a large field of view through the bones.
Timing advances of commercial divalent-ion co-doped LYSO:Ce and SiPMs in sub-100 ps time-of-flight positron emission tomography
Authors: Nadig Vanessa , Herweg Katrin , Chou Mitch M C , Lin Jack W C , Chin Edmund , Li Chu-An , Schulz Volkmar , Gundacker Stefan
Published: February 2023

Objective. Together with novel photodetector technologies and emerging electronic front-end designs, scintillator material research is one of the key aspects to obtain ultra-fast timing in time-of-flight positron emission tomography (TOF-PET). In the late 1990s, Cerium-doped lutetium–yttrium oxyorthosilicate (LYSO:Ce) has been established as the state-of-the-art PET scintillator due to its fast decay time, high light yield and high stopping power. It has been shown that co-doping with divalent ions, such as Ca 2+ and Mg 2+, is beneficial for its scintillation characteristics and timing performance. Therefore, this work aims to identify a fast scintillation material to combine it with novel photosensor technologies to push the state of the art in TOF-PET. Approach. This study evaluates commercially available LYSO:Ce,Ca and LYSO:Ce,Mg samples manufactured by Taiwan Applied Crystal Co., LTD regarding their rise and decay times as well as their coincidence time resolution (CTR) with both ultra-fast high-frequency (HF) readout and commercially available readout electronics, i.e. the TOFPET2 ASIC. Main results. The co-doped samples exhibit state-of-the-art rise times of on average 60 ps and effective decay times of on average 35 ns. Using the latest technological improvements made on NUV-MT SiPMs by Fondazione Bruno Kessler and Broadcom Inc., a 3 × 3 × 19 mm3 LYSO:Ce,Ca crystal achieves a CTR of 95 ps (FWHM) with ultra-fast HF readout and 157 ps (FWHM) with the system-applicable TOFPET2 ASIC. Evaluating the timing limits of the scintillation material, we even show a CTR of 56 ps (FWHM) for small 2 × 2 × 3 mm3 pixels. A complete overview of the timing performance obtained with different coatings (Teflon, BaSO4) and different crystal sizes coupled to standard Broadcom AFBR-S4N33C013 SiPMs will be presented and discussed. Significance. This work thoroughly evaluates commercially available co-doped LYSO:Ce crystals and, in combination with novel NUV-MT SiPMs, shows a TOF performance that significantly exceeds the current state of the art.
Enhanced electromagnetic interference shielding performance of patterned AgNWs doped MXene films in X-band
Authors: Shi Chaofan , Wang Mengyuan , Zhang Xin , Shi Wangzhou , Shi Hui , Zhang Yi
Published: February 2023

MXene based materials have a high performance in electromagnetic interference shielding. However, designing a MXene-based electromagnetic interference shielding material with broad-band, lightweight, thin thickness properties is still a challenge. In this work, we successfully fabricated patterned MXene films and MXene/silver nanowires films using laser ablation technique, which could effectively boost the shielding efficiency of materials in X-band without adding the thickness and with less weight. As shown in the results, the shielding efficiency of the patterned MXene films increased with the pattern depth, up to 37.7 dB, which is 10% larger than that of un-patterned MXene film. The silver nanowires doped patterned films had the same trend, with a maximum shielding efficiency of 38.4 dB. We attribute this effect to the small interfaces brought by engraving pattern, which can make a growing number of reflections of electromagnetic waves in the material, reduce surface reflection, and enhance the shielding efficiency of MXene. Meanwhile, we verified the enhancement mechanism by simulation. This work provides a feasible strategy to boost electromagnetic shielding efficiency without increasing the thickness and weight of material, which may have a potential application prospect.
Field coupling-induced synchronization of a functional neuron with magnetic field perception
Authors: Zhang Li , An Xinlei , Zhang Jiangang
Published: February 2023

It is difficult to explore the induced mechanism of neuronal firing activity and the cooperation between neurons experimentally, so some neuronal circuits are established to train mode transformation and selection. Furthermore, some functional device, for example, piezoelectric ceramic, thermistor, phototube are inset in neuronal circuits and the functional neurons are developed to perceive some specific physical signal. In this paper, a linear resistance and an ideal Josephson junction are parallelly connected to FitzHugh-Nagumo (FHN) neuronal circuit, and then a functional neuron is established to percept the induction currents induced by the external magnetic field. Some basic dynamics are analyzed in terms of two-parameter bifurcation, one-parameter bifurcation and interspike interval(ISI for short) bifurcation, it is indicated that the functional neuron is sensitive to the electromagnetic stimulation and has rich multimodal transformations. The period-adding bifurcations accompanied by multi-period and chaos between two period cascades occupy the entire bifurcation interval when the external magnetic field is given in steady state, while the irregular modal transformations between period and chaos can be observed when the functional neuron encounters a periodic external magnetic field. Furthermore, two functional neurons are bridged with a capacitor, so field coupling is induced, then the effects of coupling strengths on complete synchronization are investigated by calculating the synchronization error function and the bifurcation diagram. In addition, the local dynamics of the network node play an important role in collective behavior and synchronous transition, so two capacitor-coupled functional neurons is presented as the network nodes, and a chain neural network is constructed to explore the effects of external magnetic field and coupling strength on network synchronous behavior. Obviously, the orderliness of the neural network can enhance or destroy under different modulation of external magnetic stimulation and coupling strength. It can give insights to investigate synchronization on neural networks with field coupling and useful guidance for implementing artificial synapse for signal processing.
Investigation of adding metal foams and slip velocity on natural convection in a square mini-cavity
Authors: Derikvand Mohammad , Emamifar Armin
Published: February 2023

This study simultaneously investigates the impacts of adding aluminum foam and slip velocity on natural convection in a square mini-cavity using a numerical method based on Finite Volume Method with SIMPLE algorithm. In order to model various phenomena in the current study, the impacts of changing parameters such as Rayleigh number, slip factor, and Darcy number studies on streamlines, isotherms, and Nusselt number. Increasing Ra number improves the mixing fluid flow and makes vortexes bigger, leading to enhancing Nu number. Likewise, slip velocity affects the boundary layer and temperature distribution, increasing the portion of convection by around 57% in the best case. Furthermore, adding metal foam has various outcomes depending on Ra and Da numbers. The effect of aluminum foam in higher permeability is better in improving Nu number. Simultaneously adding metal foam with Da = 0.1 and slip velocity (λ = 0.1) in the square mini-cavity increases Nu number by approximately 130%. However, In the absence of slip velocity, Nu number decreases by around 6% at Da = 0.0001. So, it is noteworthy that the permeability of porous media has a critical amount in natural convection to be used positively.
Revisiting semiconductor bulk hamiltonians using quantum computers
Authors: de Souza Pimenta Raphael César , Bezerra Anibal Thiago
Published: February 2023

With the advent of near-term quantum computers, it is now possible to simulate solid-state properties using quantum algorithms. By an adequate description of the system's Hamiltonian, variational methods enable to fetch of the band structure and other fundamental properties as transition probabilities. Here, we describe semiconductor structures of the III-V family using k·p Hamiltonians and obtain their band structures using a state vector solver, a probabilistic simulator, and a real noisy-device simulator. The resulting band structures are in good agreement with those obtained by direct diagonalization of the Hamiltonian. The simulation times depend on the optimizer, circuit depth, and simulator used. Finally, with the optimized eigenstates, we convey the inter-band absorption probability, demonstrating the possibility of analyzing the fundamental properties of crystalline systems using quantum computers.
Match Zehnder interferometry and Laguerre–Gaussian fields dependent photon drag in atomic medium
Authors: Muhammad Nisar , Arif Syed Muhammad , Bacha Bakht Amin , Javed Muhammad , Khan Aurangzeb
Published: February 2023

The absorption, dispersion and transmission are controlled and modified with the intensities of Laguerre–Gaussian control fields in a four level cesium atomic medium. The normal and anomalous slope of dispersion are investigated for subluminal and superluminal propagation. The maximum measured value of positive/negative group index is n

g
=±1×107, at which, the group velocity is ±30 ms−1. The maximum delay time between the two beams at the detector without dragging is 0.414 ns and in the presence of dragging is measured to 0.44 ns. The fractional change in delay time without and in the presence of dragging Δt

F
is measured to ±2%. The maximum phase shift without dragging is reported to 2.6 micro radian and in the presence of dragging is investigated to ±4 micro radian. The fractional change in phase shift is reported from −200% to 50% and may be used for gravitational waves detection and other signals identification.
A flexible floating-gate based organic field-effect transistor non-volatile memory based on F8BT/PMMA integrated floating-gate/tunneling layer
Authors: Shu Shiyao , Xu Ting , Su Jie
Published: February 2023

The solution mixing method was adopted to build polymer semiconductor poly(9,9-dioctylflfluorene-co-benzothiadiazole) (F8BT) nanoparticles (NPs), which were mixed with poly (methyl methacrylate) (PMMA) in a solution to prepare an integrated floating-gate/tunneling layer. On this basis, flexible floating-gate based organic field-effect transistor non-volatile memories (F-OFET-NVMs) were prepared. The intrinsic correlations of the microstructures in the integrated floating-gate/tunneling layer of the memory devices with the device performance were explored. Moreover, correlations of the charge injection and discharge, physical mechanism of memory, and charge trapping capacity of the floating-gate/tunneling layer with different F8BT/PMMA mass ratios with the key parameters of memory devices were investigated. Relevant results indicate that the memory devices are able to well trap charges inside the F8BT NPs during operation at a programming voltage of +40 V, an erasing voltage of −40 V, and a pulse width of 1 s. The floating gate acquires the injected and trapped bipolar charges (electrons and holes). The optimized high-performance memory device is found to have an average memory window of 9.5 V, remain stable for more than three years, and have reliable stability in more than 100 erase/write cycles. Furthermore, the memory device also exhibits outstanding durability under mechanical bending and still has high storage stability after 6,000 times of bending with a bending radius of 3 mm. The research results powerfully promote the research progress of applying semiconductor polymers to memory devices.
New role of null lagrangians in derivation of equations of motion for dynamical systems
Authors: Das R , Musielak Z E
Published: February 2023

The space of null Lagrangians is the least investigated territory in dynamics as these Lagrangians are identically sent to zero by their Euler–Lagrange operator, and thereby they are having no effects on equations of motion. A procedure that significantly generalizes the previous work, which appeared in (2022, Physica Scripta
97, 125213), is developed and used to construct null Lagrangians and then the corresponding non-standard Lagrangians, which represent a range of interesting dynamical systems. By using the generalized procedure, derivation of equations of motion for a harmonic oscillator as well as for the Bateman and Duffing oscillators is presented. The obtained results demonstrate a new role played by the null Lagrangians and their corresponding non-standard Lagrangians in describing linear and nonlinear, and dissipative and non-dissipative dynamical systems.
Research on interference and noise reduction technology of solar radio observation system
Authors: Zhang Lei , Shen Yupeng , Wu Zhao , Yan Fabao , Su Yanrui
Published: February 2023

The dynamic spectrum of solar radio burst is a very important tool to study the characteristics of solar radio burst. However, due to the influence of the instruments noise of the solar radio telescope, external interference, the change of ambient temperature, absorption of clouds and so on, the sensitivity of the observation system will be reduced. In particular, the weak solar radio burst signal is easily submerged by various interference signals. In order to improve the sensitivity of solar radio telescope to observe solar radio burst signals and remove narrow-band interference signals, a spectrum data processing algorithm of spectral subtraction method based on entropy and energy threshold values (SSM-EE) is proposed in this article. There are multiple processing steps of SSM-EE. The first step is to improve the signal-to-noise ratio (SNR) through accumulating and averaging the spectrum data. The second step is to eliminate narrowband interference. The spectral kurtosis algorithm is used to calculate the spectral kurtosis of the narrowband interference signal, and then whether to smooth it is determined according to whether it is greater than the threshold. The third step is to establish a noise model. Calculating the power spectrum entropy and energy entropy of each frame of the processed spectrum data, judge whether it is a noise signal by judging the relationship between the power spectrum entropy and energy entropy and the corresponding threshold. The update model for noise floor is used to obtain the real-time noise floor data. The last step is to eliminate the background noise through spectral subtraction. The new spectrum data are obtained by subtraction method between the original spectrum data and the noise floor data. After a large number of data simulation and verification of the actual observation data, it shows that the method proposed in this article has good practical value.
Reaching Submillisecond Accuracy in Stellar Occultations and Artificial Satellite Tracking
Authors: Kamiński K. , Weber C. , Marciniak A. , Żołnowski M. , Gędek M.
Published: February 2023

In recent years, there appeared a need for astronomical observations timed with submillisecond accuracy. These include, e.g., timing stellar occultations by small, subkilometer, or fast near-Earth asteroids and tracking artificial satellites in low-Earth orbit using optical sensors. Precise astrometry of fast-moving satellites and accurate timing of stellar occultations have parallel needs, requiring a reliable time source and good knowledge of camera delays. Thus, there is a need for an external device that would enable equipment and camera testing to check if they reach the required accuracy in time. We designed, constructed, and thoroughly tested a New EXposure Timing Analyser (NEXTA), a Global Navigation Satellite System–based precise timer allowing us to reach an accuracy of 0.1 ms, which is an order of magnitude better than in previously available tools. The device is a simple strip of blinking diodes to be imaged with a camera and compare the imaged time with the internal camera time stamp. Our tests spanned a range of scientific cameras widely used for stellar occultations and ground-based satellite tracking. The results revealed high reliability of both NEXTA and most of the tested cameras but also pointed out that practically all cameras had internal time biases of various levels. NEXTA can serve the community, being easily reproducible with inexpensive components. We provide all the necessary schemes and usage instructions.
Non-Hermitian Ising model at finite temperature
Authors: Du Qian , Cao Kui , Kou Su-Peng
Published: February 2023

As a very simple model, the Ising model plays an important role in statistical physics. In the paper, with the help of quantum Liouvillian statistical theory, we study the one-dimensional non-Hermitian Ising model at finite temperature and give its analytical solutions. We find that the non-Hermitian Ising model shows quite different properties from those of its Hermitian counterpart. For example, the ‘pseudo-phase transition’ is explored between the ‘topological’ phase and the ‘non-topological’ phase, at which the Liouvillian energy gap is closed rather than the usual energy gap. In particular, we point out that the one-dimensional non-Hermitian Ising model at finite temperature can be equivalent to an effective anisotropic XY model in the transverse field. This work will help people understand quantum statistical properties of non-Hermitian systems at finite temperatures.
Determining the nuclear temperature dependence on source neutron-proton asymmetry in heavy-ion reactions at intermediate energy*
Authors: Qu Guofeng , Huang Yu , Zheng Hua , Liu Xingquan , Wada R. , Lin Weiping , Huang Meirong , Han Jifeng , Ren Peipei , Yang Zhenlei , Zhang Xin , Leng Qiangzhong
Published: February 2023

In this article, we investigate the dependence of nuclear temperature on emitting source neutron-proton (

) asymmetry with light charged particles (LCPs) and intermediate mass fragments (IMFs) generated from intermediate-velocity sources in thirteen reaction systems with different

asymmetries,

on

, and

,

on

,

,

, and

at 40 MeV/nucleon. The apparent temperature values of LCPs and IMFs from different systems are deduced from the measured yields using two helium-related and eight carbon-related double isotope ratio thermometers, respectively. Then, the sequential decay effect on the experimental apparent temperature deduction with the double isotope ratio thermometers is quantitatively corrected explicitly with the aid of the quantum statistical model. The present treatment is an improvement compared to our previous studies in which an indirect method was adopted to qualitatively consider the sequential decay effect. A negligible

asymmetry dependence of the real temperature after the correction is quantitatively addressed in heavy-ion reactions at the present intermediate energy, where a change of 0.1 units in source

asymmetry corresponds to an absolute change in temperature of an order of 0.03 to 0.29 MeV on average for LCPs and IMFs. This conclusion is in close agreement with that inferred qualitatively via the indirect method in our previous studies.
Thickness measurements and uncertainty evaluation of a multilayer thin-film sample using auxiliary single-layer samples
Authors: Park Jungjae , Bae Jaeseok , Jang Yoon-Soo , Jin Jonghan
Published: February 2023

Multilayer thin-film structures are widely used for many different types of devices in the semiconductor, display, and battery manufacturing industries. In such devices, the thickness of each layer should be strictly controlled to meet desired performance requirements. Various measurement techniques have been utilized to take thickness measurements, but verification of these measurements continues to rely on simple comparisons. In this study, for an uncertainty evaluation of a multilayer thin-film structure, a four-layer multilayer sample (SiO2-SiN-SiON-SiO2) with each layer having a nominal thickness of 100 nm was fabricated together with auxiliary single-layer thin-film samples fabricated at the time of each deposition step for each layer. The multilayer sample and auxiliary samples (ASs) were measured using a calibrated spectral reflectometer, after which their interference spectra were analyzed to determine their thicknesses through a model-based analysis. Based on the measurement results, the uncertainty of the multilayer sample was evaluated by considering two components: the uncertainty of the AS, which included the thickness analysis resolution, measurement repeatability, and thickness uniformity; and the thickness offset between the four-layer multilayer sample and the ASs. Finally, the measurement uncertainties of the thin-film thicknesses in the multilayer sample were evaluated and found to be 10.8 nm at the first layer, 9.8 nm at the second layer, 7.8 nm at the third layer, and 3.3 nm at the fourth layer.
In silico study of the effects of cerebral circulation on source localization using a dynamical anatomical atlas of the human head
Authors: Lahtinen Joonas , Moura Fernando , Samavaki Maryam , Siltanen Samuli , Pursiainen Sampsa
Published: February 2023

Objective. This study focuses on the effects of dynamical vascular modeling on source localization errors in electroencephalography (EEG). Our aim of this in silico study is to (a) find out the effects of cerebral circulation on the accuracy of EEG source localization estimates, and (b) evaluate its relevance with respect to measurement noise and interpatient variation. Approach. We employ a four-dimensional (3D + T) statistical atlas of the electrical properties of the human head with a cerebral circulation model to generate virtual patients with different cerebral circulatory conditions for EEG source localization analysis. As source reconstruction techniques, we use the linearly constraint minimum variance (LCMV) beamformer, standardized low-resolution brain electromagnetic tomography (sLORETA), and the dipole scan (DS). Main results. Results indicate that arterial blood flow affects source localization at different depths and with varying significance. The average flow rate plays an important role in source localization performance, while the pulsatility effects are very small. In cases where a personalized model of the head is available, blood circulation mismodeling causes localization errors, especially in the deep structures of the brain where the main cerebral arteries are located. When interpatient variations are considered, the results show differences up to 15 mm for sLORETA and LCMV beamformer and 10 mm for DS in the brainstem and entorhinal cortices regions. In regions far from the main arteries vessels, the discrepancies are smaller than 3 mm. When measurement noise is added and interpatient differences are considered in a deep dipolar source, the results indicate that the effects of conductivity mismatch are detectable even for moderate measurement noise. The signal-to-noise ratio limit for sLORETA and LCMV beamformer is 15 dB, while the limit is under 30 dB for DS. Significance. Localization of the brain activity via EEG constitutes an ill-posed inverse problem, where any modeling uncertainty, e.g. a slight amount of noise in the data or material parameter discrepancies, can lead to a significant deviation of the estimated activity, especially in the deep structures of the brain. Proper modeling of the conductivity distribution is necessary in order to obtain an appropriate source localization. In this study, we show that the conductivity of the deep brain structures is particularly impacted by blood flow-induced changes in conductivity because large arteries and veins access the brain through that region.
MHD simulation on magnetic compression of field reversed configurations with NIMROD
Authors: Ma Y. , Zhu P. , Rao B. , Li H.
Published: February 2023

Magnetic compression has long been proposed a promising method for plasma heating in a field reversed configuration (FRC). However, it remains a challenge to fully understand the physical mechanisms underlying the compression process, due to its highly dynamic nature beyond the one-dimensional (1D) adiabatic theory model (Spencer et al 1983 Phys. Fluids
26 1564). In this work, magnetohydrodynamics simulations on the magnetic compression of FRCs using the NIMROD code (Sovinec et al 2004 J. Comput. Phys.
195 355) and their comparisons with the 1D theory have been performed. The effects of the assumptions of the theory on the compression process have been explored, and the detailed profiles of the FRC during compression have been investigated. The pressure evolution agrees with the theoretical prediction under various initial conditions. The axial contraction of the FRC can be affected by the initial density profile and the ramping rate of the compression magnetic field, but the theoretical predictions on the FRC’s length in general and the relation

r
s

=

2

r
o

in particular hold approximately well during the whole compression process, where r

s
is the major radius of FRC separatrix and r

o
is that of the magnetic axis. The evolutions of the density and temperature can be affected significantly by the initial equilibrium profile and the ramping rate of the compression magnetic field. During the compression, the major radius of the FRC is another parameter that is susceptible to the ramping rate of the compression field. Basically, for the same magnetic compression ratio, the peak density is higher and the FRC’s radius r

s
is smaller than the theoretical predictions.
3D simulation of orbit loss and heat load on limiters of ICRF-NBI synergy induced fast ions on EAST
Authors: Zheng Y. , Zhang W. , Li G. , Yin L. , Hao B.
Published: February 2023

Fast ions synergy induced by ion-cyclotron range of frequency (ICRF) and neutral beam injection (NBI) are of interest not only because of their advantage of heating the plasma and drive currents, but also because of their disadvantage of damaging plasma surface components and driving MHD instabilities. In this paper, we calculate the fast ion loss and the deposition distribution of the lost particles on the limiters in EAST under the synergistic effect of the ripple field and collisions with the full-orbit-following simulation program ISSDE for the first time. The previous models to study the NBI fast ion loss by the action of ICRF are relatively simple and consider fewer influencing factors. Most studies on fast ion loss have used toroidal uniform boundaries. In this work, we consider the distribution of ICRF-NBI synergy induced fast ions with different minority H concentrations. After setting the limiter boundary, we consider the prompt fast ion loss caused by the equilibrium field and the fast ion loss caused by the ripple field and collision. Under the action of minority-ion ion-cyclotron resonant heating, the NBI fast ion distribution function has spread in the high-energy part, especially for the minority H concentration of 1%, and the fast ions show each anisotropic distribution near the resonance band on the poloidal dimension. The synergistic loss caused by the ripple field and collision will first be greater than the loss caused by either factor, and then reach a final loss fraction of 3.8%. The heat load power density of the lost fast ions on different limiters is not uniform, as well as on each limiter, which is related to the distance from the limiter to the plasma, the relative position between the limiters and the parallel direction of most fast ions. Once the study of ICRF-NBI synergy induced fast ion loss caused by the action of ripple and collision has been done, we can do optimization in a targeted manner. Such as adding ferromagnetic inserts to reduce the ripple loss and optimizing the limiters’ position to reduce or control the generation of impurities.
Electron beam welding of AlCoCrFeNi2.1 high entropy alloy to EN 1.4301 austenitic steel
Authors: Rončák J , Adam O , Zobač M
Published: February 2023

Eutectic high-entropy alloys (EHEA), also known as multi-principle component alloys (MPCA), are a group of materials exhibiting promising mechanical properties. The principle of the alloy is to achieve sufficient ductility due to the presence of the soft phase and, at the same time, increased strength due to the hard phase. In order for the newly discovered types of materials to be used commercially, it is necessary to verify their behaviour in technological operations such as welding processes. Therefore, the objective of the experiment was to evaluate the heterogeneous welded joint of the AlCoCrFeNi2.1 alloy with commercially used austenitic steel EN 1.4301 by electron beam welding. The parameters used during the process were previously verified on homogeneous joints. Subsequent observations were made by light and electron microscopy supplemented by chemical analysis. The mechanical properties of the formed joint were verified by a Vickers hardness test.
IEC 62264 standard-based manufacturing operations management resource modelling for electron beam welding
Authors: Vasilev P , Koleva E
Published: February 2023

The development and deployment of a Manufacturing Operations Management (MOM) system for electron beam welding aims the integration and organization of the accumulated knowledge for the process, and the application of this knowledge for the improvement of the modelling and control capabilities, their efficiency, adaptability, flexibility and re-configurability, as well as integration with other technological processes. The paper presents the Unified Modelling Language (UML) information modelling of electron beam welding installation as a part of an IEC 62264 standard-based manufacturing operations management system development.