bluuebunny/crossref_metadata_2025 huggingface dataset:
Thiourea-catalysed conjugate additions of amines to vinyl phosphonates and phosphinates
Authors: McDermott Peter E. , Fearraigh Martin P. Ó. , Horan Alexandra M. , McGarrigle Eoghan M.
Published: January 2023

Thiourea catalysts activated α,β-unsaturated phosphonates and phosphinates toward conjugate addition by amines to give β-aminophosphonates and β-aminophosphinates.
Statistical copolymer metal organic nanotubes
Authors: Barrett Jacob A. , Rosenmann Nathan D. , Gnanasekaran Karthikeyan , Carroll Xian B. , Gianneschi Nathan C. , Jenkins David M.
Published: January 2023

The first multivariate ligand MONTs were prepared and characterized and showed statistical copolymerization.
The dynamic balance of the skin microbiome across the lifespan
Authors: Townsend Elizabeth C. , Kalan Lindsay R.
Published: January 2023

For decades research has centered on identifying the ideal balanced skin microbiome that prevents disease and on developing therapeutics to foster this balance. However, this single idealized balance may not exist. The skin microbiome changes across the lifespan. This is reflected in the dynamic shifts of the skin microbiome's diverse, inter-connected community of microorganisms with age. While there are core skin microbial taxa, the precise community composition for any individual person is determined by local skin physiology, genetics, microbe–host interactions, and microbe–microbe interactions. As a key interface with the environment, the skin surface and its appendages are also constantly exchanging microbes with close personal contacts and the environment. Hormone fluctuations and immune system maturation also drive age-dependent changes in skin physiology that support different microbial community structures over time. Here, we review recent insights into the factors that shape the skin microbiome throughout life. Collectively, the works summarized within this review highlight how, depending on where we are in lifespan, our skin supports robust microbial communities, while still maintaining microbial features unique to us. This review will also highlight how disruptions to this dynamic microbial balance can influence risk for dermatological diseases as well as impact lifelong health.
Loss of brain energy metabolism control as a driver for memory impairment upon insulin resistance
Authors: Duarte João M. N.
Published: January 2023

The pathophysiological mechanisms intersecting metabolic and neurodegenerative disorders include insulin resistance, which has a strong involvement of environmental factors. Besides central regulation of whole-body homeostasis, insulin in the central nervous system controls molecular signalling that is critical for cognitive performance, namely signalling through pathways that modulate synaptic transmission and plasticity, and metabolism in neurons and astrocytes. This review provides an overview on how insulin signalling in the brain might regulate brain energy metabolism, and further identified molecular mechanisms by which brain insulin resistance might impair synaptic fuelling, and lead to cognitive deterioration.
A self‐distillation object segmentation method via frequency domain knowledge augmentation
Authors: Chen Lei , Cao Tieyong , Zheng Yunfei , Fang Zheng
Published: January 2023

Most self‐distillation methods need complex auxiliary teacher structures and require lots of training samples in object segmentation task. To solve this challenging, a self‐distillation object segmentation method via frequency domain knowledge augmentation is proposed. Firstly, an object segmentation network which efficiently integrates multi‐level features is constructed. Secondly, a pixel‐wise virtual teacher generation model is proposed to drive the transferring of pixel‐wise knowledge to the object segmentation network through self‐distillation learning, so as to improve its generalisation ability. Finally, a frequency domain knowledge adaptive generation method is proposed to augment data, which utilise differentiable quantisation operator to adjust the learnable pixel‐wise quantisation table dynamically. What's more, we reveal convolutional neural network is more inclined to learn low‐frequency information during the train. Experiments on five object segmentation datasets show that the proposed method can enhance the performance of the object segmentation network effectively. The boosting performance of our method is better than recent self‐distillation methods, and the average Fβ and mIoU are increased by about 1.5% and 3.6% compared with typical feature refinement self‐distillation method.
A reliable optimization framework using ensembled successive history adaptive differential evolutionary algorithm for optimal power flow problems
Authors: Premkumar Manoharan , Kumar Chandrasekaran , Dharma Raj Thankkapan , Sundarsingh Jebaseelan Somasundaram David Thanasingh , Jangir Pradeep , Haes Alhelou Hassan
Published: January 2023

The Optimal Power Flow (OPF) is a primary tool in planning and installing power systems. It attempts to minimize the operating costs associated with generating and transmitting electrical power by modifying control parameters to satisfy environmental, economic, and operational constraints. Implementing an efficient and robust optimization algorithm for the above‐said problem is critical to achieving such a typical objective. Therefore, this paper introduces and evaluates new variants of the Successive History‐based Adaptive Differential Evolutionary (SHADE) algorithm called ESHADE, SHADE‐SFS, and SHADE‐SAP to solve the OPF problems with equality and inequality constraints. Generally, the static penalty approach is widely used for eliminating infeasible solutions discovered during the search phase when searching for feasible solutions. This approach requires the accurate selection of penalty coefficients, accomplished through the trial‐and‐error method. The proposed ESHADE algorithm is formulated using Self‐Adaptive Penalty (SAP) and Superiority of Feasible Solution (SFS) mechanisms to obtain feasible solutions for OPF problems. Two IEEE bus systems are used to demonstrate the effectiveness of the proposed algorithm in handling OPF problems. The fuel cost and active power loss obtained by the proposed algorithm are better than other state‐of‐the‐art algorithms. The results reveal that the proposed framework offers significant advantages over other algorithms.
New insights on the near-infrared veiling of young stars using CFHT/SPIRou data
Authors: Sousa A. P. , Bouvier J. , Alencar S. H. P. , Donati J.-F. , Dougados C. , Alecian E. , Carmona A. , Rebull L. , Cook N. , Artigau E. , Fouqué P. , Doyon R. ,   the SLS consortium
Published: January 2023

Context. Veiling is ubiquitous at different wavelength ranges in classical T Tauri stars. However, the origin of the veiling in the infrared (IR) domain is not well understood at present. The accretion spot alone is not enough to explain the shallow photospheric IR lines in accreting systems, suggesting that another source is contributing to the veiling in the near-infrared (NIR). The inner disk is often quoted as the additional emitting source meant to explain the IR veiling.

Aims. In this work, we aim to measure and discuss the NIR veiling to understand its origins and variability timescale.

Methods. We used a sample of 14 accreting stars observed with the CFHT/SPIRou spectrograph, within the framework of the SPIRou Legacy Survey, to measure the NIR veiling along the YJHK bands. We compared the veiling measurements with accretion and inner disk diagnostics. We also analyzed circumstellar emission lines and photometric observations from the literature.

Results. The measured veiling grows from the Y to the K band for most of the targets in our sample. The IR veiling agrees with NIR emission excess obtained using photometric data. However, we also find a linear correlation between the veiling and the accretion properties of the system, showing that accretion contributes to the inner disk heating and, consequently, to the inner disk emission excess. We also show a connection between the NIR veiling and the system’s inclination with respect to our line of sight. This is probably due to the reduction of the visible part of the inner disk edge, where the NIR emission excess is expected to arise, as the inclination of the system increases. Our search for periods on the veiling variability showed that the IR veiling is not clearly periodic in the typical timescale of stellar rotation – which, again, is broadly consistent with the idea that the veiling comes from the inner disk region. The NIR veiling appears variable on a timescale of a day, showing the night-by-night dynamics of the optical veiling variability. In the long term, the mean NIR veiling seems to be stable for most of the targets on timescales of a month to a few years. However, during occasional episodes of high accretion in classical T Tauri stars, which affect the system’s dynamic, the veiling also seems to be much more prominent at such times, as we found in the case of the target RU Lup.

Conclusions. We provide further evidence that for most targets in our sample, the veiling that mainly occurs in the JHK bands arises from dust in the inner disk.
Determination of the impact of strain rate on dynamic recrystallization of hot-deformed 2205 duplex stainless steel
Authors: Baruwa A. D. , Gonya E. , Makhatha M. E.
Published: January 2023

2205 duplex stainless steel suffers poor hot workability, especially whe1981hot-deformed. This investigation aims to determine the strain rate’s effect on the material’s dynamic recrystallization after heat treatment. Secondly, to ascertain the critical strain at which the recrystallization occurs. The as-rolled material was subjected to heat treatment at 1340 °C for some time. After heat treatment, the yielded equiaxed austenite morphology was used for this investigation. Gleeble 1500™ thermo-mechanical was used as a simulant in uniaxial compression mode. The deformation temperature was set at 850 °C, with maximum strain at 0.8 and carried out at 0.001 s-1, 0.01 s-1, 0.1 s-1, 1 s-1, 5 s-1 strain rates. The microstructure of before and after heat-treatment was evaluated using a light microscope, while the critical factors (stress and strain) were determined through the stress-strain curve. It was observed that the lowest strain rate generated the maximum critical stress and critical strain at 191.99 MPa and 0.08283, respectively. However, at the highest strain rate, the maximum critical stress and critical strain experienced by the material were at 336.32 MPa and 0.17577. Overall, it was established that the applied stain rate influenced the critical strain and stress of the material. It can be concluded that dynamic recrystallization can occur at any strain rate, but the applied stress determines the extent of the phenomenon.
WTX beyond WNT signaling pathway
Authors: Zhang Qingling , Hu Qi , Li Jian , Lin Zhirui
Published: January 2023

Gastric cancer (GC) is a major malignancy in many developing countries with low early detection rate. As a tumour suppressor gene, WTX inhibits PI3K/AKT/mTOR pathway activity by inhibiting PI3K phosphorylation. WTX loss of WTX protein associates with tumor metastasis and poor survival of GC patients. During GC progression, an aberrantly elevated miR-20a-5p expression has been found, which inhibits WTX expression and induces PI3K phosphorylation, thereby activating the PI3K/AKT/mTOR pathway and promoting cellular proliferation and migration. A new mechanism in which miR-20a-5p promotes GC progression by regulating WTX expression to control PI3K/AKT/mTOR pathway activity has been recently discovered. These findings might be useful for developing novel therapeutics to inhibit the progression of GC.
Neuraxial Anesthesia during the COVID-19 Pandemic: Report from a Large Academic Medical Center
Authors: Ogunkua Olutoyosi T. , Adhikari Emily H. , Gasanova Irina , Jalloh Miakka N. , Syed Sannoor S. , Pruszynski Jessica E. , Spong Catherine Y.
Published: January 2023

Objective Three primary neuraxial techniques reduce labor pain: epidural, dural puncture epidural (DPE), and combined spinal-epidural (CSE). This study aims to determine whether neuraxial analgesia techniques changed after the onset of the coronavirus disease 2019 (COVID-19) pandemic. Given that a dural puncture confirms neuraxial placement, we hypothesized that DPE was more frequent in women with concerns for COVID-19.

Study Design A single-center retrospective cohort study comparing neuraxial analgesia techniques for labor and delivery pain management before and after the onset of the COVID-19 pandemic and in patients with and without SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) at a maternity hospital in Dallas, Texas, with a large delivery service. Statistical analyses included the Chi-square test for categorical and Kruskal–Wallis test for nonparametric ordinal comparisons. The Cochran–Mantel–Haenszel test was used to assess the association between neuraxial technique and accidental dural puncture or postdural puncture headache.

Results Of 10,971 patients who received neuraxial analgesia for labor, 5,528 were delivered in 2019 and 5,443 in 2020. Epidural analgesia was the most common neuraxial technique for labor pain in 2019 and 2020. There was no difference in the frequency of neuraxial analgesia techniques or the rates of accidental dural puncture or postdural puncture headaches comparing all deliveries in 2019 to 2020. Despite a significant increase in DPEs relative to epidurals in the SARS-CoV-2-positive group compared with the SARS-CoV-2-negative group in 2020, there was no significant difference in postdural puncture headaches or accidental dural punctures.

Conclusion The advantages of a DPE, specifically the ability to confirm epidural placement using a small gauge spinal needle, likely led to an increase in the placement of this neuraxial in SARS-CoV-2-positive patients. There was no effect on the frequency of postdural puncture headaches or accidental dural punctures within the same period.

Key Points
Sex-Dependent Differences in Mouse Placental Gene Expression following a Maternal High-Fat Diet
Authors: Grace Matthew R. , Vora Neeta L. , Smeester Lisa , Dotters-Katz Sarah K. , Fry Rebecca C. , Bae-Jump Victoria , Boggess Kim
Published: January 2023

Objective In utero fetal exposures may have sex-specific placental gene responses. Our objective was to measure sex-based differences in placental gene expression from dams fed high-fat diet (HFD) versus control diet (CD).

Study Design We fed timed pregnant Friend virus B–strain dams either a CD (n = 5) or an HFD (n = 5). We euthanized dams on embryonic day 17.5 to collect placentas. We extracted placental RNA and hybridized it to a customized 96-gene Nanostring panel focusing on angiogenic, inflammatory, and growth genes. We compared normalized gene expression between CD and HFD, stratified by fetal sex, using analysis of variance. Pathway analysis was used to further interpret the genomic data.

Results Pups from HFD-fed dams were heavier than those from CD-fed dams (0.97 ± 0.06 vs. 0.84 ± 0.08 g, p < 0.001). Male pups were heavier than females in the HFD (0.99 ± 0.05 vs. 0.94 ± 0.06 g, p = 0.004) but not CD (0.87 ± 0.08 vs. 0.83 ± 0.07 g, p = 0.10) group. No sex-based differences in placental gene expression in CD-fed dams were observed. Among HFD-fed dams, placentas from female pups exhibited upregulation of 15 genes (q = 0.01). Network analyses identified a cluster of genes involved in carbohydrate metabolism, cellular function and maintenance, and endocrine system development and function (p = 1 × 10−23). The observed female-specific increased gene expression following in utero HFD exposure was predicted to be regulated by insulin (p = 5.79 × 10−13).

Conclusion In female compared with male pups, in utero exposure to HFD upregulated placental gene expression in 15 genes predicted to be regulated by insulin. Sex-specific differences in placental expression of these genes should be further investigated.

Key Points
Exploring Silyl Protecting Groups for the Synthesis of Carbon Nanohoops
Authors: Šolomek Tomáš , Kręcijasz Remigiusz B. , Malinčík Juraj
Published: January 2023

The synthesis of topological molecular nanocarbons, such as hoop-like [n]cycloparaphenylenes, requires the use of spatially prearranged, pro-aromatic units to overcome a build-up of large molecular strain in their curved structures. The used cyclohexadienyl units, however, contain tertiary alcohols that need protection to prevent side reactions until the aromatization step that affords the final curved hydrocarbon. Although alkyl and triethylsilyl groups have been successfully applied as protecting groups for this purpose, each suffers from specific drawbacks. Here, we explore the potential of sterically more crowded silyl groups, namely, tert-butyldimethylsilyl and triisopropylsilyl, as alternatives to the established protection strategies. We show that tert-butyldimethylsilyl can be easily installed and removed under mild conditions, displaying markedly higher resistance towards acids or bases than the triethylsilyl group used to date. Unlike in the case of alkyl groups, tert-butyldimethylsilyl also preserves a high stereoselectivity during the nucleophilic additions of ArLi. Furthermore, we demonstrate that both tert-butyldimethylsilyl and triethylsilyl groups can be installed on the same substrate, and that the latter be selectively deprotected. Thus, the high stereoselectivity, improved stability, and easy deprotection make tert-butyldimethylsilyl an excellent protecting group for the synthesis of carbon nanohoops.
A Preliminary Study on the Frequency of Influenza Infections during the Early 2022 Amid COVID-19 Epidemic in Libya
Authors: Alhudiri Inas M. , Saad Saad R. , Abusrewil Zakarya , Amer Asel O. , El Meshri Salah Edin , Bin Abdallah Mohamed Nasir , Elghazal Mohamed M. , Said Mohamed H. , Ebrahim Fawzi O. , Abusanina Mohamed S. , Ben Elfghi Mohammed , Abdusalam Mohamed M. , Elzagheid Adam
Published: January 2023

Background At the time of conducting this study, we were at the peak of the influenza season, and influenza vaccinations were not readily accessible throughout the country. Thus, predisposing many high-risk individuals to influenza infections in a time when coronavirus disease 2019 (COVID-19) was also highly circulating, and the emerging Omicron variant of concern was peaking in many countries worldwide.

Materials and Methods We conducted a brief survey to prospectively estimate the frequency of influenza A and B and severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) in samples received at our laboratories at Libyan Biotechnology Research Center, Tripoli, Libya, between December 1, 2021, and January 31, 2022, for patients complaining of respiratory symptoms using a multiplex reverse transcription-polymerase chain reaction test for SARS-COV-2, influenza A and B, and RSV.

Results We analyzed nasopharyngeal swabs in viral transport media from 2,186 samples. About 27% (589/2186) of study patients tested positive for SARS-COV-2, 2.8% (61/2186) were positive for influenza A virus, 0.18% (4/2186) for influenza B virus, and 1.4% (31/2186) tested positive for RSV.

Conclusions These results revealed that along with COVID-19, influenza infections were also rising. As the COVID-19 pandemic continues, the most significant concern is the development of an influenza outbreak in the upcoming months. Therefore, continuing annual influenza vaccination is critical to increasing population immunity. National influenza surveillance and testing should also be conducted. Furthermore, sequencing and antigenic characterization should be performed regularly. There is a need for continuous monitoring in national laboratories to detect any zoonotic cases and substantial viral evolution.
Rash and Gastrointestinal Dysfunction May Indicate Cardiac Involvement in Children with Multisystem Inflammatory System Associated with Coronavirus Disease 2019
Authors: Pektaş Ayhan , Bükülmez Ayşegül , Çeleğen Mehmet , Eker İbrahim
Published: January 2023

Objective This study aims to investigate the management of children diagnosed with “multisystem inflammatory syndrome” (MIS-C) potentially associated with coronavirus disease 2019 (COVID-19) at a tertiary health center.

Methods This is a retrospective review of 34 children who were diagnosed with MIS-C at the pediatrics department of the study center from August 2021 to December 2021. Data related to age, sex, body mass index, vital findings, laboratory data, clinical symptoms, ultrasonography, and echocardiography findings were acquired from hospital records. Cardiac markers were compared with respect to clinical symptoms and imaging.

Results Fever (91.2%), rash (50%), and abdominal pain (44.1%) were the most observed symptoms. Echocardiography visualized mild mitral regurgitation in 12 patients (35.3%), pericardial effusion in 9 patients (26.5%), and mild coronary dilatation in 9 patients (26.5%). All patients received corticosteroids, whereas acetylsalicylic acid was prescribed in 29 patients (85.3%) and intravenous immunoglobulins were administered in 21 patients (61.8%). Serum probrain natriuretic peptide concentrations were significantly higher in MIS-C patients with rash than those without rash (9,592.2 ± 7,764.5 vs. 1,501.2 ± 1,385.4 pg/mL, p = 0.021). Serum troponin T concentrations were significantly higher in MIS-C patients with ileitis than those without ileitis (0.026 ± 0.024 vs. 0.008 ± 0.003 µg/L, p = 0.013). Serum troponin T concentrations were also significantly higher in MIS-C patients with pericardial effusion than those without pericardial effusion (0.022 ± 0.020 vs. 0.008 ± 0.007 µg/L, p = 0.036).

Conclusion The presence of rash and sonographic visualization of ileitis might act as signs for cardiac involvement in children exposed to COVID-19. To assess the cardiac involvement in MIS-C patients, cardiac enzymes should be measured and echocardiography examination should be performed.
Corporate governance of Islamic banks: a sustainable model to protect the participatory depositor?
Authors: Franzoni Simona , Ait Allali Asma
Published: January 2023

The religious principles that characterize the Islamic bank have direct consequences on the models of Corporate Governance which, at the same time, must be in accordance with national and international regulations and best practices. The aim of this paper is to analyze the role of the participatory depositor in the Corporate Governance Models of the Islamic Bank, a special category of stakeholder that entrusts their savings to the Islamic Bank on the basis of the Profit and Loss Sharing principle. In the present study the models of Corporate Governance of the Islamic Bank, with regard to the protection of the interests of the participatory depositor, are analyzed through a comparative analysis of the regulations of the following Countries, Malaysia and Morocco. The objective is to highlight the strengths and weaknesses of the protection of the interests of affected stakeholders in order to verify the presence of a sustainable model of Corporate Governance, namely if the participatory depositor needs more guarantees than other categories of stakeholders.
Evaluating the Contribution of Complex International Research-for-Development Programmes to the Sustainable Development Goals
Authors: Lu-Gonzales Arlene , Tsusaka Takuji W. , Szabo Sylvia , Kadigi Reuben M. J. , Foglietti Camilla Blasi , Park Seree , Matthews Zoe
Published: January 2023

While evaluation of research-to-policy projects is a fundamental aspect of measuring the impact of new knowledge, limited studies have examined evaluation methods in such projects, as well as how the evaluation can generate learning to facilitate the progress towards the Sustainable Development Goals (SDGs). This study conducted a systematic literature review and found that the most commonly used methods for SDG contribution evaluation were Analytical Hierarchy Process (40.4%), Fuzzy TOPSIS (13.2%) and ELECTRE and SPADE Methodology (3.5% each). Ranking analysis was undertaken to determine priorities among the six “Big Wins” as defined for the UKRI-GCRF Trade Hub Project, as a case, where the ranking was exercised by the project partners across the globe. Results revealed that “nature and social factors” was better considered in international trade agreements as the priority (36.4%) among others. Moreover, among the four “mechanisms” of the project, “knowledge, networks, and connectivity” was ranked as the top priority (56.9%), followed by “capacity building” (28.5%), “metrics, tools and models” (7.2%), and “improving the knowledge base” (4.6%). Mapping and evaluation revealed that the Big Wins of the Trade Hub contributed to ten out of the 17 SDGs. The most fulfilled goals were SDG 12 (Sustainable Consumption and Production), SDG 15 (Life on Land), and SDG 2 (Zero Hunger) in descending order. Furthermore, interaction analysis of the core SDGs revealed both synergy and tradeoff between different outputs. The research articles reviewed for this paper showed no gold standard framework for assessing international development projects against the SDGs. Further research should develop a tool to capture holistic and synergistic contributions of the target outcomes of projects to sustainable development.
Cubic first integrals of autonomous dynamical systems in E2 by an algorithmic approach
Authors: Mitsopoulos Antonios , Tsamparlis Michael
Published: January 2023

In a recent paper of Mitsopoulos and Tsamparlis [J. Geom. Phys. 170, 104383 (2021)], a general theorem is given, which provides an algorithmic method for the computation of first integrals (FIs) of autonomous dynamical systems in terms of the symmetries of the kinetic metric defined by the dynamical equations of the system. In the present work, we apply this theorem to compute the cubic FIs of autonomous conservative Newtonian dynamical systems with two degrees of freedom. We show that the known results on this topic, which have been obtained by means of various divertive methods, and the additional ones derived in this work can be obtained by the single algorithmic method provided by this theorem. The results are collected in Tables I–IV, which can be used as an updated reference for these types of integrable and superintegrable potentials. The results we find are for special values of free parameters; therefore, using the methods developed here, other researchers by a different suitable choice of the parameters will be able to find new integrable and superintegrable potentials.
Interface formation and Schottky barrier height for Y, Nb, Au, and Pt on Ge as determined by hard x-ray photoelectron spectroscopy
Authors: Rumaiz Abdul K. , Weiland Conan , Harding Ian , Nooman Neha S. , Krings Thomas , Hull Ethan L. , Giacomini Gabriele , Chen Wei , Cockayne Eric , Siddons D. Peter , Woicik Joseph C.
Published: January 2023

Development of a robust, thin, hole-blocking (n+) contact on high purity germanium (HPGe) has been the main challenge in the development of Ge-based radiation sensors. Yttrium has been reported to be a viable hole-blocking contact on HPGe, and detectors with low leakage have been fabricated. Niobium has also been considered as a potential hole-blocking contact due to its low work function. Here, we investigate interface chemistry and the Schottky barrier height of Y and Nb, as well as electron-blocking contacts Au and Pt, on Ge(100) surfaces using hard x-ray photoelectron spectroscopy. We find a barrier height of 1.05 ± 0.10 eV for Y/HPGe, confirming the formation of a hole-blocking barrier. For Nb/HPGe, the barrier height of 0.13 ± 0.10 eV demonstrates that the interface is not hole-blocking. The Schottky barrier of Au and Pt was found to be 0.45 ± 0.10 and 0.51 ± 0.10 eV, respectively.
Existence of exotic magnetic phases along with exchange bias and memory effect in frustrated beta-Mn Heusler alloy
Authors: Dixit Srishti , Ghosh Labanya , Alam Mohd , Kumar Satya Vijay , Patel Neha , Ghosh Swayangsiddha , Shahi Nisha , Singh Sanjay , Chatterjee Sandip
Published: January 2023

Generally, Co-based Heusler alloys are the center of interest because of their properties such as high Curie temperature, spin polarization, and high value of exchange bias. Herein, we have used the macroscopic technique to probe the low-temperature exotic properties of M1.5Co0.5FeAl. First, we have analyzed the dc magnetization data, and it unfolds the presence of a glassy phase at 33 K. The cluster spin glass phase is authenticated by measuring ac susceptibility. Furthermore, using empirical models like power law and Vogel–Fulcher fitting, the relaxation time for the spin is of the order of τ ∼ 10−9 s, confirming the presence of a cluster spin glass in Mn1.5Co0.5FeAl below an irreversible temperature. The H–T phase space diagram ensures that it follows the Ising spin model. Furthermore, the glassy phase of the system is confirmed by magnetic relaxation, memory effect, and the presence of an exchange bias instead of a minor loop below spin-freezing temperature (Tf  ∼ 33 K).
Characterization of the turbulent field behavior of an elevated jet-in crossflow investigated using direct numerical simulation
Authors: Behera Sachidananda , Khan Basheer A. , Saha Arun K.
Published: January 2023

Direct numerical simulation (DNS) of a turbulent flow in an elevated jet in crossflow has been carried out at a Reynolds number (Re) of 3500 based on the outer width of the stack and crossflow velocity. The jet to crossflow velocity ratio is kept constant at VR=2. Second order spatial and temporal discretization have been used to solve the Navier–Stokes equations employing a high-resolution grid to determine the essential characteristics of the coherent and the incoherent flow fields accurately. The large-scale coherent and small-scale incoherent flow fields are extracted using a reference signal-based phase-averaged method that uses a reference signal against which the phases are identified in each cycle to minimize the phase jitter. The rate of decay of circulation of the stack-wake vortices is observed to be more than that of the jet-wake which has a lower circulation value. The contribution of the incoherent fluctuations to the total turbulent kinetic energy is more compared to its coherent counterpart in the wake as well as jet region, except for the near-wake of the stack. The normal and shear stresses of both coherent and incoherent fields reveal a relatively higher contribution in the near-wake of both stack-wake and jet-wake, while the far-wake shows the opposite trend. The anisotropy factor of both the large-scale coherent and the small-scale fluctuating fields provides the evidence of total anisotropy of the stack-wake. The characterization of both types of fluctuating fields is also carried out using the anisotropy-invariant-map which displays the one-component limit for the coherent fluctuating field in most of the regions, but the anisotropy state of the incoherent fluctuating field is found to switch among various limits, namely, the axisymmetric contraction, the axisymmetric expansion, and isotropic limits.
Structural, electronic, magnetic, and optical investigations of sodium chalcogenides: First-principles calculations
Authors: Jaradat Raed T. , Abu-Jafar Mohammed S. , Farout Mahmoud , Azar Said M. , Khenata Rabah , Mousa Ahmad A.
Published: January 2023

The electronic, magnetic, and optical properties of NaS and NaSe compounds have been studied by using first-principles calculations based on density-functional theory and full-potential linearized augmented plane-wave method. The Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA) and modified Becke–Johnson (mBJ-GGA) have been used to deal with the exchange-correlation potential. The PBE-GGA and mBJ-GGA electronic calculation of the spin-up configuration shows an insulating behavior, while the spin-down shows a metallic behavior. In addition, both PBE-GGA and mBJ-GGA agree that the total magnetic moment per unit cell for these compounds is 1 μB. From optical calculations, we see that ε1(0) value in the spin-up channel is positive, which shows an insulating character, while it has a large negative value for the spin-down configuration, which shows a metallic character. The NaS and NaSe refractive index n(ω) indicates a metallic demeanor as the real and imaginary parts of the dielectric constant.
A transimpedance preamplifier using a feedforward approach for robust rejection of DC photogenerated currents
Authors: Masetti Ettore , Cattini Stefano , Rovati Luigi
Published: January 2023

The preamplifier proposed in this paper is designed to extract weak variable photogenerated signals from a high-level continuous background ensuring low noise and high transimpedance gain. An efficient cancellation of the DC component directly at the photodetector output, exploiting a feedforward approach, allows us to properly amplify the variable signal components of interest avoiding saturation of the preamplifier. Furthermore, the large transimpedance gain allows for minimizing the effects of the noise introduced by the following stages on the signal processing chain. In the paper, we present the proposed approach and a possible circuit realization with a signal AC/DC ratio as small as 1/1000 ensuring low noise, high gain, and a considerable bandwidth. The realized preamplifier offers a Noise Equivalent Power NEP ≃ 1.12 nW, an in-band transimpedance gain of 4.4 MΩ, and a wide bandwidth from about 1 Hz up to 100 kHz, making it suitable for use in several applications both in biomedical and industrial fields.
Mitigation of lamp oven and cavity oven temperature-induced frequency variation in rubidium atomic clock
Authors: Guo Yonggang , Wang Shiwei , Zhu Lili , Cai Zhiwei , Lu Fang , Li Wenxin , Liu Zhidong
Published: January 2023

The long-term frequency stability of the rubidium atomic clock is primarily affected by temperature variations in the lamp oven and the cavity oven, which cause changes in light intensity, which are then converted into frequency variations. Therefore, we propose using light intensity variations to actively improve the cavity oven and lamp oven temperature sensitivity of the rubidium atomic clock. This is accomplished through research into the theory of the rubidium atomic frequency standard, specifically the effect of light intensity, lamp oven temperature, and cavity oven temperature on the frequency deviation. In previous work, we discovered the relationship between the light intensity and frequency deviation by combining this with our engineering expertise. Furthermore, some related experiments show that the method is feasible with the lamp oven and cavity oven temperature sensitivity of the rubidium atomic clock greatly improved, providing an effective way to improve the rubidium atomic clock’s long-term frequency stability.
Ultrafast laser heating for controlling the optoelectronic properties of sulfur hyperdoped black silicon
Authors: Mc Kearney Patrick , Schäfer Sören , Paulus Simon , Roser Michael , Piermaier Fabian , Lebershausen Ingo , Kontermann Stefan Ralf
Published: January 2023

Ultrashort pulse laser processed sulfur hyperdoped black silicon represents a promising silicon-based material for infrared optoelectronic applications due to its high sub-bandgap optical absorptance. Non-thermal melting and resolidification processes associated with such laser processing, however, result in amorphous and polycrystalline phases which may be detrimental for this purpose. Furthermore, the sulfur impurities are electrically inactive, impeding the formation of a rectifying junction. This work demonstrates an ultrafast laser heating process based on heat accumulation with laser pulses of 10 ps pulse duration at high repetition rates of 41 MHz and peak fluences between 33% and 66% of the ablation threshold as a method to (i) recrystallize the material and (ii) electrically activate the sulfur dopants while (iii) maintaining the sub-bandgap absorption. Furthermore, laser heating recovers the optical activity of sulfur states that have been previously deactivated by thermal annealing. The demonstrated process can have versatile applications in material functionalization due to its highly localized heat input accompanied by high cooling rates.
Nb–Nb direct bonding at room temperature for superconducting interconnects
Authors: Fujino Masahisa , Araga Yuuki , Nakagawa Hiroshi , Takahashi Yuta , Nanba Kenji , Yamaguchi Ayami , Miyata Akira , Nishi Takanori , Kikuchi Katsuya
Published: January 2023

Superconducting devices with high-density integration are required for applications, such as high-performance detectors and quantum computing. Here, the direct bonding of Nb electrodes at room temperature using a surface activated bonding method was investigated. We directly bonded Nb bonding pads and then performed current–voltage measurements in a 3He cryostat. A superconducting current of 1–5 mA was confirmed for the bonded interconnect. The transition temperature was 7.3–9.3 K. These values are affected by the quality of the bonding interface. According to cross-sectional transmission electron microscopy observations and energy-dispersive x-ray spectroscopy analysis of the bonding interface, the Nb layers were bonded with a 3-nm-thick intermediate layer made of Si and Nb between them. The Si sources were the bonding substrate and the bonding jig in the bonding apparatus.
Do we need perfect mixing between fuel and oxidizer to maximize the energy release rate of energetic nanocomposites?
Authors: Wang Haiyang , Jiang Yue , Wang Yujie , Kline Dylan J. , Zheng Xiaolin , Zachariah Michael R.
Published: January 2023

It is well accepted that close assembly between a fuel and an oxidizer can increase the interfacial contact-area and reduce the diffusion distances, which can significantly promote a heterogeneous reaction. However, we recently observed for nanocomposites of Al/PVDF (aluminum/polyvinylidene fluoride), that if we separated some of the PVDF to form a laminated structure, the flame propagation rate is significantly increased compared to the homogenous case. To probe the mechanism behind this, we used functionalized aluminum nanoparticles to create microsized aggregates of Al-rich and PVDF-rich regions to induce the inhomogeneity and also fabricated Al/PVDF laminate structure films to control the inhomogeneity systematically. The result demonstrates that the inhomogeneous mixing between Al and PVDF can significantly increase the flame front corrugation (burning area). This presumably occurs due to variations in the microburn rate (local burn velocity vectors at the flame front on the microscale). The benefit of the enhanced flame area can apparently overcome the effects of the decrease in the contact area, leading to enhanced burning for an inhomogeneously mixed system. Finally, fluorocarbon functionalization of Al particles can further increase the microburn rate.
Design of LDO circuit based on curvature compensation reference closed-loop stability
Authors: Ren Sheng-Le , Ren Ming-Yuan , Gao Tian-Hang
Published: January 2023

In this paper, a low dropout (LDO) circuit based on a curvature compensation benchmark and closed-loop stability is designed. This circuit compensates for the higher order term of VBE in a BJT through the subthreshold characteristic of MOSFET and achieves the effect of curvature compensation. The bandgap reference circuit provides a stable input voltage for the LDO circuit, while the source follower and adaptive bias circuit improve the response speed and closed-loop stability of the LDO circuit. The temperature drift coefficient of the bandgap circuit is 8.11 ppm/°C, the input voltage is 3–5 V, the output voltage is 2.8 V, and the linear adjustment rate is 0.22%.
Effect of charge diameter on detonation parameters in the mixture of gelled nitromethane/microballoons
Authors: Mochalova Valentina , Utkin Alexander , Shakula Mikhail , Lavrov Vladimir
Published: January 2023

In this work, the detonation wave structure and detonation parameters of mixtures of gelled nitromethane (NM) with hollow glass microballoons (GMBs) are investigated with a laser velocimetry technique. It is shown that the addition from 0.5 to 13 wt. % GMB with the mean diameter of 70 μm does not qualitatively change the reaction zone structure of gelled NM, and it corresponds to the Zeldovich–von Neumann–Döring theory, predicting the formation of the von Neumann spike. The detonation parameters of the explosive mixture monotonically decrease—in particular, the ideal detonation velocity drops from 6.3 km/s for gelled NM to 3.7 km/s for its mixture with 13 wt. % GMB. The addition of GMB leads to a significant reduction in the critical detonation diameter, which decreases from 16.5 mm in gelled NM to 3.5 mm in the mixture with 8 wt. % GMB. The influence of polymethylmethacrylate concentration in the mixture of gelled NM with GMB on the value of critical diameter of the mixture is observed.
Fluid mechanics of air recycling and filtration for indoor airborne transmission
Authors: Krishnaprasad K. A. , Salinas J. S. , Zgheib N. , Balachandar S.
Published: January 2023

We present a statistical framework to account for effects of recycling and filtration in ventilation systems for the estimation of airborne droplet nuclei concentration in indoor spaces. We demonstrate the framework in a canonical room with a four-way cassette air-conditioning system. The flow field within the room is computed using large eddy simulations for varying values of air changes per hour, and statistical overloading is used for droplet nuclei, which are tracked with a Langevin model accounting for sub-grid turbulence. A key element is to break up the path that a virus-laden droplet nucleus can take from the time it is ejected by the sick individual to the time it reaches the potential host into four separate elementary processes. This approach makes it possible to provide turbulence-informed and statistically relevant pathogen concentration at any location in the room from a source that can be located anywhere else in the room. Furthermore, the approach can handle any type of filtration and provides a correction function to be used in conjunction with the well-mixed model. The easy-to-implement correction function accounts for the separation distance between the sick and the susceptible individuals, an important feature that is inherently absent in the well-mixed model. The analysis shows that using proper filtration can increase the cumulative exposure time in typical classroom settings by up to four times and could allow visitations to nursing homes for up to 45 min.
Genetic analysis and identification of QTLs associated with yield-enhancing traits in Oryza sativa IR64 × Oryza glaberrima interspecific backcross populations
Authors: Bharamappanavara Muralidhara , Chikkahosahalli Manoj Appaiah , Patil Basavaraj Siddanagouda , Vijjeswarapu Ajitha , Anantha M. Siddaih , Ramappa Lokesha , Diwan Jayateertha , Nidagundi Jayaprakash Mohan , Mathada Umesh Rangappa , Talagunda Suma Chandrasekhara , Guddalahalli Lokesh Yellaiah , Byanna Rajanna , Rathod Santosha , Sundaram Raman Meenakshi , Subbarao Lella Venkata , Rapolu Mahender Kumar , Gireesh Channappa
Published: January 2023

Context Broadening the gene pool of staple food crops by incorporating desirable genes from wild/relative species is way to achieve higher genetic gains. The African rice species Oryza glaberrima Steud. is a source of genes for genetic improvement of Oryza sativa L. to various biotic and abiotic stresses. Aim The study was undertaken to identify genomic regions associated with yield and yield-related traits in interspecific backcross mapping populations derived from variety IR64 (O. sativa indica) × O. glaberrima. Methods The BC1F2 and BC1F2:3 populations were phenotyped for days to 50% flowering, plant height, number of tillers, number of productive tillers, panicle length, spikelet fertility and grain yield under irrigated conditions. The BC1F2 population was genotyped with 99 genome-wide polymorphic SSR markers. Quantitative trait loci (QTLs) associated with yield-enhancing traits were identified through single marker analysis. Key results Significant genetic variability was observed with moderate to high heritability in mapping populations. Genotyping revealed the presence of segregation distortion and skewed genome composition. Single marker analysis identified 20 QTLs linked to the studied traits. A QTL linked to grain yield, qGY-4.1, derived from O. glaberrima was found in both populations with high phenotypic variance. The chromosome region around marker RM510 was identified as a QTL hotspot and putative candidate genes were identified. Conclusions Our study demonstrates that O. glaberrima can serve as a valuable genetic resource for genetic improvement of yield-enhancing traits in O. sativa cultivars. Implications The identified QTLs regions can be employed in molecular breeding. The promising introgression lines identified can be used as pre-breeding lines in future breeding programs.
The evolution of Al2CuMg phase during two-stage homogenisation for 7055 aluminium alloy
Authors: Ma Dong , Xu Chunjie , Guo Can , Wu Xiangquan , Tian Jun , Zhang Zhongming , Remennik Sergei , Shechtman Dan
Published: January 2023

In this paper, the effect of two-stage homogenisation treatment on the evolution of the second phase was investigated. The microstructure of the extruded 7055 aluminium alloy was composed of α(Al) matrix and other second phases, including MgZn2, Al2CuMg, and Al7Cu2Fe phases. The segregation of second phase was serious and the content was 27.9%. During the 460°C × 24 h homogenisation, MgZn2 phases dissolved quickly, but there was still a significant amount of Al2CuMg phases present. After two-stage homogenisation (460°C × 24 h + 480°C × 10 h), the content of Al2CuMg phase decreased from 15% to 3% and the degree of segregation was reduced. In addition, the mechanical properties of the extruded 7055 alloy were effectively improved.
Plastin 3 rescues cell surface translocation and activation of TrkB in spinal muscular atrophy
Authors: Hennlein Luisa , Ghanawi Hanaa , Gerstner Florian , Palominos García Eduardo , Yildirim Ezgi , Saal-Bauernschubert Lena , Moradi Mehri , Deng Chunchu , Klein Teresa , Appenzeller Silke , Sauer Markus , Briese Michael , Simon Christian , Sendtner Michael , Jablonka Sibylle
Published: January 2023

Plastin 3 (PLS3) is an F-actin-bundling protein that has gained attention as a modifier of spinal muscular atrophy (SMA) pathology. SMA is a lethal pediatric neuromuscular disease caused by loss of or mutations in the Survival Motor Neuron 1 (SMN1) gene. Pathophysiological hallmarks are cellular maturation defects of motoneurons prior to degeneration. Despite the observed beneficial modifying effect of PLS3, the mechanism of how it supports F-actin-mediated cellular processes in motoneurons is not yet well understood. Our data reveal disturbed F-actin-dependent translocation of the Tropomyosin receptor kinase B (TrkB) to the cell surface of Smn-deficient motor axon terminals, resulting in reduced TrkB activation by its ligand brain-derived neurotrophic factor (BDNF). Improved actin dynamics by overexpression of hPLS3 restores membrane recruitment and activation of TrkB and enhances spontaneous calcium transients by increasing Cav2.1/2 “cluster-like” formations in SMA axon terminals. Thus, our study provides a novel role for PLS3 in supporting correct alignment of transmembrane proteins, a key mechanism for (moto)-neuronal development.
Discrete Calderón problem with partial data
Authors: Lecaros Rodrigo , Ortega Jaime H , Pérez Ariel , De Teresa Luz
Published: January 2023

In this work, we are interested in analyzing the well-known Calderón problem, which is an inverse boundary value problem of determining a coefficient function of an elliptic partial differential equation from the knowledge of the associated Dirichlet-to-Neumann map on the boundary of a domain. We consider the discrete version of the Calderon inverse problem with partial boundary data; in particular, we establish logarithmic stability estimates for the discrete Calderón problem, in dimension

d
⩾
3

, for the discrete H
−r
-norm on the boundary under suitable a priori bounds. The proof of our main result is based on a new discrete Carleman estimate for the discrete Laplacian operator with boundary observations.