bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabonomics analysis of flavonoids in seeds and sprouts of two Chinese soybean cultivars
Authors: Bi Weiwei , Zhao Guixing , Zhou Yutong , Xia Xiaoyu , Wang Jinsheng , Wang Guangjin , Lu Shuwen , He Wenjin , Bi Taifei , Li Jinrong
Published: April 2022

A popular food in China, soybean seeds and sprouts contained many biologically active substances which are beneficial to the human body, such as flavonoids. Northeast of China is the main producing area of soybean. The experimental materials came from the main soybean producing areas in Northeast China, this study compared flavonoids of two China cultivars of soybeans, Heinong52(HN52) and Heinong71(HN71). Here, we also considered the effects of germination on the chemical profile of flavonoids. Using a LC–ESI–MS/MS system, 114 differential flavonoid metabolites were identified. A total of 18 metabolites were significantly different between the two soybean varieties before germination, of which 14 were up-regulated and 4 were down-regulated. After germination, 33 significantly different metabolites were found in the two soybean sprouts, of which 19 were up-regulated and 14 were down-regulated. These experimental results revealed significant up-regulation of metabolites in soybean sprouts compared with soybean seeds, thus suggesting that soybean germination may increase content of flavonoid metabolites. There are six main pathways for the synthesis of flavonoids: isoflavonoid biosynthesis, flavonoid biosynthesis, flavone and flavonol biosynthesis, biosynthesis of secondary metabolites, and biosynthesis of phenylpropanoids. Soybean seeds lack flavone and flavanol biosynthesis and develop the capacity for this biosynthetic pathway after germination as sprouts. Isoflavonoid biosynthesis is the most abundantly utilized pathway.
Exploring the performances of the vibrating barriers for the seismic protection of the Zoser pyramid
Authors: Cacciola P. , Shadlou M. , Ayoub A. , Rashed Y. F. , Tombari A.
Published: April 2022

In this paper we aim to investigate the use of the Vibrating Barrier (ViBa) as a potential strategy to mitigate the effects of the seismic action on the Zoser Pyramid. The Vibrating Barrier is a structure buried in the soil that is able to absorb a significant portion of the dynamic energy arising from the ground motion. The working principle exploits the dynamic interaction among vibrating structures resting on a compliant semi-infinite space, namely the structure–soil–structure interaction. A reliable numerical simulation of the Zoser Pyramid and the surrounding soil undergoing stochastic ground motion excitations representing the seismicity in Saqqara is presented. Due to the unique structural form, the ViBa is herein optimized through an ad-hoc procedure to minimize a response strain energy spectral density used as a synthetic performance parameter. Various layouts of the ViBa have been considered and presented in the paper. The efficiency of the ViBa is assessed by numerical simulation of the finite element model of the ViBa-Soil-Pyramid system and by laboratory testing. Results from a pertinent Monte Carlo study show an evident reduction of the stresses in the Pyramid manifesting the feasibility of this novel strategy to protect historic structures from earthquake-induced ground motion. Experimental results on a 1:500 gelatine model of the pyramid and the surrounding area highlighted the efficiency and efficacy of the proposed approach.
Equivalency of four research-grade movement sensors to assess movement behaviors and its implications for population surveillance
Authors: Migueles Jairo H. , Molina-Garcia Pablo , Torres-Lopez Lucia V. , Cadenas-Sanchez Cristina , Rowlands Alex V. , Ebner-Priemer Ulrich W. , Koch Elena D. , Reif Andreas , Ortega Francisco B.
Published: April 2022

the benefits of physical activity (PA) and sleep for health, accurate and objective population-based surveillance is important. Monitor-based surveillance has potential, but the main challenge is the need for replicable outcomes from different monitors. This study investigated the agreement of movement behavior outcomes assessed with four research-grade activity monitors (i.e., Movisens Move4, ActiGraph GT3X+, GENEActiv, and Axivity AX3) in adults. Twenty-three participants wore four monitors on the non-dominant wrist simultaneously for seven days. Open-source software (GGIR) was used to estimate the daily time in sedentary, light, moderate-to-vigorous PA (MVPA), and sleep (movement behaviors). The prevalence of participants meeting the PA and sleep recommendations were calculated from each monitor’s data. Outcomes were deemed equivalent between monitors if the absolute standardized difference and its 95% confidence intervals (CI95%) fell within ± 0.2 standard deviations (SD) of the mean of the differences. The participants were mostly men (n = 14, 61%) and aged 36 (SD = 14) years. Pairwise confusion matrices showed that 83–87% of the daily time was equally classified into the movement categories by the different pairs of monitors. The between-monitor difference in MVPA ranged from 1 (CI95%: − 6, 7) to 8 (CI95%: 1, 15) min/day. Most of the PA and sleep metrics could be considered equivalent. The prevalence of participants meeting the PA and the sleep guidelines was 100% consistent across monitors (22 and 5 participants out of the 23, respectively). Our findings indicate that the various research-grade activity monitors investigated show high inter-instrument reliability with respect to sedentary, PA and sleep-related estimates when their raw data are processed in an identical manner. These findings may have important implications for advancement towards monitor-based PA and sleep surveillance systems.
Early Triassic ichthyopterygian fossils from the Russian Far East
Authors: Nakajima Yasuhisa , Shigeta Yasunari , Houssaye Alexandra , Zakharov Yuri D. , Popov Alexander M. , Sander P. Martin
Published: April 2022

Ichthyopterygia is a major clade of reptiles that colonized the ocean after the end-Permian mass extinction, with the oldest fossil records found in early Spathian substage (late Olenekian, late Early Triassic) strata in the western USA. Here, we describe reptilian remains found in situ in the early Spathian Neocolumbites insignis ammonoid zone of South Primorye in the Russian Far East. Specimen NSM PV 23854 comprises fragmentary axial elements exhibiting a combination of morphological characteristics typical of Ichthyopterygia. The cylindrical centra suggest that the specimen represents a basal ichthyopterygian, and its size is comparable to that of Utatsusaurus. Specimen NSM PV 24995 is represented by a single limb bone, which is tentatively identified as an ichthyopterygian humerus. With a body length of approximately 5 m estimated from the humeral length, NSM PV 24995 represents one of the largest specimens of early Spathian marine reptiles known to date. Such size variation among the earliest ichthyopterygians might suggest an explosive diversification in size immediately after the end-Permian mass extinction. Both vertebrae and humerus specimens exhibit an extremely cancellous inner structure, suggesting a high degree of aquatic adaptation in ichthyopterygians, despite their short history of evolution in the ocean.
Cryogenic TEM imaging of artificial light harvesting complexes outside equilibrium
Authors: Krishnaswamy Sundar Raj , Gabrovski Ivo A. , Patmanidis Ilias , Stuart Marc C. A. , de Vries Alex H. , Pshenichnikov Maxim S.
Published: April 2022

The energy transport in natural light-harvesting complexes can be explored in laboratory conditions via self-assembled supramolecular structures. One such structure arises from the amphiphilic dye C8S3 molecules, which self-assemble in an aqueous medium to a double-wall cylindrical nanotube reminiscent of natural light-harvesting complexes found in green sulphur bacteria. In this paper, we report a way to investigate the structure of inner nanotubes (NTs) alone by dissolving the outer NTs in a microfluidic setting. The resulting thermodynamically unstable system was rapidly frozen, preventing the reassembly of the outer NT from the dissolved molecules, and imaged using cryogenic transmission electron microscopy (cryo-TEM). The experimental cryo-TEM images and the molecular structure were compared by simulating high-resolution TEM images, which were based on the molecular modelling of C8S3 NTs. We found that the inner NT with outer walls removed during the flash-dilution process had a similar size to the parent double-walled NTs. Moreover, no structural inhomogeneity was observed in the inner NT after flash-dilution. This opens up exciting possibilities for functionalisation of inner NTs before the reassembly of the outer NT occurs, which can be broadly extended to modify the intra-architecture of other self-assembled nanostructures.
Direct and latent effects of ocean acidification on the transition of a sea urchin from planktonic larva to benthic juvenile
Authors: Dorey Narimane , Butera Emanuela , Espinel-Velasco Nadjejda , Dupont Sam
Published: April 2022

Ongoing ocean acidification is expected to affect marine organisms and ecosystems. While sea urchins can tolerate a wide range of pH, this comes at a high energetic cost, and early life stages are particularly vulnerable. Information on how ocean acidification affects transitions between life-history stages is scarce. We evaluated the direct and indirect effects of pH (pHT8.0, 7.6 and 7.2) on the development and transition between life-history stages of the sea urchinStrongylocentrotusdroebachiensis,from fertilization to early juvenile. Continuous exposure to low pH negatively affected larval mortality and growth. At pH 7.2, formation of the rudiment (the primordial juvenile) was delayed by two days. Larvae raised at pH 8.0 and transferred to 7.2 after competency had mortality rates five to six times lower than those kept at 8.0, indicating that pH also has a direct effect on older, competent larvae. Latent effects were visible on the larvae raised at pH 7.6: they were more successful in settling (45% at day 40 post-fertilization) and metamorphosing (30%) than larvae raised at 8.0 (17 and 1% respectively). These direct and indirect effects of ocean acidification on settlement and metamorphosis have important implications for population survival.
A multi-omics approach to elucidate the mechanisms of action of a dietary muramidase administered to broiler chickens
Authors: Brugaletta Giorgio , De Cesare Alessandra , Laghi Luca , Manfreda Gerardo , Zampiga Marco , Oliveri Chiara , Pérez-Calvo Estefanía , Litta Gilberto , Lolli Susanna , Sirri Federico
Published: April 2022

A novel dietary muramidase has been shown to have positive effects on broiler chickens. However, very little is known about its mechanisms of action. The present multi-omics investigation sought to address this knowledge gap. A total of 2,340 day-old male broilers were assigned to 3 groups (12 replicates each) fed, from 0 to 42 d, a basal diet (control group—CON) or the basal diet supplemented with muramidase at 25,000 (low-dose group—MUL) or 45,000 LSU(F)/kg feed (high-dose group—MUH). MUH significantly outperformed CON in terms of cumulative feed intake (4,798vs4,705 g), body weight (2,906vs2,775 g), and feed conversion ratio (1.686vs1.729), while MUL exhibited intermediate performance. At caecal level, MUH showed the lowest alpha diversity, a significantly different beta diversity, a reduction in Firmicutes, and a rise in Bacteroidetes, especially compared with MUL. MUH also exhibited a considerable decrease in Clostridiaceae and an overrepresentation of Bacteroidaceae and Lactobacillaceae. At blood level, MUH had lower hypoxanthine—probably due to its drop at caecal level—histidine, and uracil, while greater pyruvate, 2-oxoglutarate, and glucose. This study sheds light on the mode of action of this muramidase and lays the groundwork for future investigations on its effects on the intestinal ecosystem and systemic metabolism of broiler chickens.
Metabolomics approach to assess the effect of siphonal autotomy on metabolic characteristics of razor clam Solen grandis
Authors: Wu Yangping , Chen Aihua , Zhang Yu , Zhang Zhidong , Cao Yi , Chen Suhua , Tian Zhen , Li Qiujie
Published: April 2022

Autotomy appendages are fundamental evolutionary adaptations to escape predation. The siphon is an important foraging organ for bivalves. Here, we report the first demonstration of autotomy of the siphon in marine bivalves (razor clam Solen grandis) and the effect of siphonal autotomy in S. grandis on foraging and metabolic characteristics. In this study, the feeding rate and digestive enzyme activities upon siphonal autotomy in razor clams were investigated. Moreover, endogenous metabolites pre/post-autotomy of the siphon were investigated using liquid chromatography tandem-mass spectrometry (LC–MS). The feeding rate and digestive enzyme activities decreased significantly after siphonal autotomy in S. grandis (P < 0.05), suggesting that autotomy of the siphon negatively affected its foraging. These results might be related to the reduction in the foraging radius. Additionally, the effect of autotomy was investigated on a total of 34 differentially abundant metabolites, and pathway analysis indicated that 32 differentially enriched metabolic pathways were worthy of attention. Further integrated key metabolic pathway analysis showed that glycine, serine and threonine metabolism; taurine and hypotaurine metabolism; biotin metabolism; vitamin B6 and thiamine metabolism were significantly relevant pathways in S. grandis pre/post-autotomy of the siphon. The downregulation of glycine, taurine, and hypotaurine is expected to indicate a shortage of intermediate compounds and energy in S. grandis. Therefore, to provide the required energy and materials for siphon regeneration in S. grandis, we anticipated that it would be necessary to supplement these as exogenous metabolites from the daily diet.
Analysis of individual-level data from 2018–2020 Ebola outbreak in Democratic Republic of the Congo
Authors: Vossler Harley , Akilimali Pierre , Pan Yuhan , KhudaBukhsh Wasiur R. , Kenah Eben , Rempała Grzegorz A.
Published: April 2022

The 2018–2020 Ebola virus disease epidemic in Democratic Republic of the Congo (DRC) resulted in 3481 cases (probable and confirmed) and 2299 deaths. In this paper, we use a novel statistical method to analyze the individual-level incidence and hospitalization data on DRC Ebola victims. Our analysis suggests that an increase in the rate of quarantine and isolation that has shortened the infectiousness period by approximately one day during the epidemic’s third and final wave was likely responsible for the eventual containment of the outbreak. The analysis further reveals that the total effective population size or the average number of individuals at risk for the disease exposure in three epidemic waves over the period of 24 months was around 16,000–a much smaller number than previously estimated and likely an evidence of at least partial protection of the population at risk through ring vaccination and contact tracing as well as adherence to strict quarantine and isolation policies.
Growth promotion and antibiotic induced metabolic shifts in the chicken gut microbiome
Authors: Plata Germán , Baxter Nielson T. , Susanti Dwi , Volland-Munson Alyssa , Gangaiah Dharanesh , Nagireddy Akshitha , Mane Shrinivasrao P. , Balakuntla Jayanth , Hawkins Troy B. , Kumar Mahajan Arvind
Published: April 2022

Antimicrobial growth promoters (AGP) have played a decisive role in animal agriculture for over half a century. Despite mounting concerns about antimicrobial resistance and demand for antibiotic alternatives, a thorough understanding of how these compounds drive performance is missing. Here we investigate the functional footprint of microbial communities in the cecum of chickens fed four distinct AGP. We find relatively few taxa, metabolic or antimicrobial resistance genes similarly altered across treatments, with those changes often driven by the abundances of core microbiome members. Constraints-based modeling of 25 core bacterial genera associated increased performance with fewer metabolite demands for microbial growth, pointing to altered nitrogen utilization as a potential mechanism of narasin, the AGP with the largest performance increase in our study. Untargeted metabolomics of narasin treated birds aligned with model predictions, suggesting that the core cecum microbiome might be targeted for enhanced performance via its contribution to host-microbiota metabolic crosstalk.
Plasmonic random laser enabled artefact-free wide-field fluorescence bioimaging: uncovering finer cellular features
Authors: Gayathri R. , Suchand Sandeep C. S. , Gummaluri V. S. , Asik R. Mohamed , Padmanabhan Parasuraman , Gulyás Balázs , Vijayan C. , Murukeshan V. M.
Published: April 2022

An artefact-free, wide-field fluorescence bioimaging modality based on spatially incoherent plasmonic random laser is proposed and demonstrated for the first time for high contrast in vivo bioimaging.
Sulfonated biochar catalyst derived from eucalyptus tree shed bark: synthesis, characterization and its evaluation in oleic acid esterification
Authors: Yusuff Adeyinka S. , Thompson-Yusuff Kudirat A. , Porwal Jyoti
Published: April 2022

Herein, fatty acid (oleic acid, OA) was upgraded to fatty acid methyl ester (FAME) via esterification reaction using sulfonated biochar obtained from eucalyptus tree shed bark as solid acid catalyst.
Determination of microRNA-122 in hepatocytes by two-step amplification of duplex-specific nuclease with laser-induced fluorescence detection
Authors: Yu Xiufeng , Zhang Shaoyan , Wang Wei
Published: April 2022

A method of two-step amplification of duplex-specific nuclease with laser-induced fluorescence detection for the determination of miR-122 in hepatocytes.
Charge-induced proton penetration across two-dimensional clay materials
Authors: Shi Le , Gao Yushuan , Ying Zhixuan , Xu Ao , Cheng Yonghong
Published: April 2022

The presence of negative surface charges on 2D clay nanosheets can dramatically reduce the proton penetration energy barrier to about one-third that of the neutral case.
From 4-arm star proteins to diverse stimuli-responsive molecular networks enabled by orthogonal genetically encoded click chemistries
Authors: Fok Hong Kiu Francis , Yang Zhongguang , Jiang Bojing , Sun Fei
Published: April 2022

The integrated use of genetically encoded click chemistries and protein topology engineering enabled the creation of various smart protein hydrogels.
Solution [2 + 2] photopolymerization of biomass-derived nonrigid biscinnamate monomers enabled by energy transfer catalysis
Authors: Jiang Yu , Ma Qiang , Zhang Xun , Li Junfang , Liao Saihu
Published: April 2022

Visible light-mediated [2 + 2] photopolymerization of nonrigid biscinnamate monomers has been realized in solution via energy transfer catalysis, featuring its operation simplicity, controllability, and a general monomer scope.
Conformational and structural stability of n and 2-propylthiols: a revisit
Authors: Tripathi Manish Kumar , Ramanathan Venkatnarayan
Published: April 2022

C–C and C–S bond rotations give four minima for nP molecules. Computational predictions reinforced by ESPM, MCA, NBO, FMO and NCI analyses excellently matched with experimental results.
Enhanced stability of complex coacervate core micelles following different core-crosslinking strategies
Authors: Kembaren Riahna , Kleijn J. Mieke , Borst Jan Willem , Kamperman Marleen , Hofman Anton H.
Published: April 2022

The stability of complex coacervate core micelles (C3Ms) against salt and pH changes is improved by chemical crosslinking of the micelle core. Depending on the crosslinking agent, the resulting covalent network is reversible or irreversible.
Excellent electrocatalytic performance of metal-free thiophene–sulfur covalent organic frameworks for hydrogen evolution in alkaline medium
Authors: Ma Yunchao , Fu Yue , Jiang Wei , Wu Yuanyuan , Liu Chunbo , Che Guangbo , Fang Qianrong
Published: April 2022

Two metal-free 2D COF materials were synthesized by Schiff base reaction, which showed excellent HER activity in alkaline medium. The two structures were through DFT calculated, and the relationship between band gap and overpotential was analyzed.
A hierarchically porous sponge for stabilized emulsion separation with high filtration flux and separation efficiency
Authors: Cao Jinfeng , Wang Wenyu , Feng Shengyu
Published: April 2022

A silicone sponge with hierarchical pore structures was prepared. It can be used to separate oil–water mixtures, and oil-in-water and water-in-oil emulsions with ultrafast separation flux, high efficiency, and good durability.
A Developmental Approach to Assessing and Treating Agrammatic Aphasia
Authors: Dyson Bronwen , Håkansson Gisela , Ballard Kirrie J.
Published: April 2022

Purpose:

There is mounting evidence that the agrammatism that defines Broca's aphasia can be explained in processing terms. However, the extant approach simply describes agrammatism as disparate deficits in a static, mature system. This tutorial aims to motivate and outline a developmental alternative. This alternative is processability theory (PT), a root-to-apex theory of language development, with its origins in the field of second language acquisition, which can connect the findings of aphasia research.

Method:

This tutorial critically reviews research on agrammatism as a language deficit, a representational deficit, and a processing phenomenon. Given evidence from research applying PT to language disorders, this tutorial outlines PT's multidimensional architecture of language processing. Using an emergence (onset) criterion, PT predicts fixed developmental stages in word order (syntax) and inflection (morphology) and individual differences in the timing of syntax and morphology. To link PT to agrammatism, this theory's applications to diagnosis and teaching are overviewed, and a case study of five individuals with moderate agrammatism is presented.

Results:

Analysis showed that all individuals were positioned in the early PT stages and differed in their timing of syntax and morphology consistent with theoretical predictions.

Conclusions:

Evidence from the case study suggests that, although agrammatism results from neural damage and associated language loss, the processing procedures necessary for relearning remain and can be exploited for recovery. A program of diagnosis and intervention is proposed, and future research directions are discussed.

Supplemental Material:

https://doi.org/10.23641/asha.19416488
Effects of Tongue-Strengthening Exercise on Tongue Strength and Effortful Swallowing Pressure in Young Healthy Adults: A Pilot Study
Authors: Fukuoka Tatsuyuki , Ono Takahiro , Hori Kazuhiro , Kariyasu Makoto
Published: April 2022

Purpose:

The purpose of this study was to investigate the effects of tongue-strengthening exercise (TSE) on tongue strength and effortful swallowing pressure in young healthy adults.

Method:

Thirteen young healthy volunteers (six men, seven women;
M
age
= 20.5 ± 0.5 years) performed 8 weeks of isometric TSE 3 days per week. A tongue pressure measurement device was used to measure maximum isometric tongue pressure (MITP) and conduct the TSE, and a tactile sensor system attached to the hard palate was used to measure effortful swallowing pressure. MITP and effortful swallowing pressure were measured at baseline, after 4 and 8 weeks of training, and at 4 and 8 weeks after the last training session to examine the detraining effects.

Results:

The results indicated that both MITP and effortful swallowing pressure increased significantly from baseline to 8 weeks after training. Although the improved MITP significantly decreased at 4 and 8 weeks after training cessation, no detraining effect was observed for effortful swallowing pressure.

Conclusions:

TSE is an effective method for increasing tongue pressure in wide tongue–palate contact areas during effortful swallow. The effortful swallowing pressure gained with TSE appears to be maintained for at least eight nontraining weeks.
Sandwich‐structured PPy‐TiO2/PVDF composite films with outstanding dielectric properties and energy density
Authors: Qiu Jinyue , Weng Ling , Zhang Xiaorui , Su Yu
Published: April 2022

Improving the energy storage density of dielectric capacitors has absorbed extensive attention for energy storage. However, a decrease in breakdown strength may be aroused after the addition of abundant fillers, it is necessary to design the composite film with a sandwich structure without the sacrifice of mechanical properties. The PPy‐TiO2/PVDF monolayer film and PVDF/PPy‐TiO2/PVDF sandwich‐structured composite films were successfully prepared via electrospinning and a hot‐press treatment. The experiment results show that the dielectric constant of the composite films can be enhanced effectively by adding PPy‐TiO2.When the filling amount is 30 wt%, the energy storage density of PVDF/PPy‐TiO2/PVDF sandwich‐structured composite films is outstanding before the breakdown strength, which is higher than that of the pure PVDF film. The energy storage density of PVDF/PPy‐TiO2/PVDF sandwich‐structured composite films could be achieved to 2.68 J/cm3 under the electric strength of 1700 kV/cm.
Gas phase Elemental abundances in Molecular cloudS (GEMS)
Authors: Esplugues G. , Fuente A. , Navarro-Almaida D. , Rodríguez-Baras M. , Majumdar L. , Caselli P. , Wakelam V. , Roueff E. , Bachiller R. , Spezzano S. , Rivière-Marichalar P. , Martín-Doménech R. , Muñoz Caro G. M.
Published: April 2022

Context. In the context of the IRAM 30 m Large Program Gas phase Elemental abundances in Molecular CloudS (GEMS), we present a study of thioformaldehyde (H2CS) and its deuterated versions (HDCS and D2CS) in several starless cores located in a selected set of star-forming filaments of Taurus, Perseus, and Orion. These regions have different star formation activities and, therefore, distinct physical and chemical conditions.

Aims. Our goal is to investigate the influence of the environmental conditions on the abundances of these molecules in the cores, as well as the effect of time evolution.

Methods. We have modelled the observed lines of H2CS, HDCS, and D2CS using the radiative transfer code RADEX. We have also used the chemical code Nautilus to model the evolution of these species depending on the characteristics of the starless cores.

Results. We derive column densities and abundances for all the cores. We also derive deuterium fractionation ratios, Dfrac, which allow us to determine and compare the evolutionary stage between different parts of each star-forming region. Our results indicate that the north region of the B 213 filament in Taurus is more evolved than the south, while the north-eastern part of Perseus presents an earlier evolutionary stage than the south-western zone. Model results also show that Dfrac decreases with the cosmic-ray ionisation rate, while it increases with density and with the degree of sulphur depletion. In particular, we can only reproduce the observations when the initial sulphur depletion in the starless cores is at least one order of magnitude lower than the solar elemental sulphur abundance.

Conclusions. The progressive increase in HDCS/H2CS and D2CS/H2CS with time makes these ratios powerful tools for deriving the chemical evolutionary stage of starless cores. However, they cannot be used to derive the temperature of these regions, since both ratios present a similar evolution at two different temperature ranges (~7–11 K and ~ 15–19 K). Regarding chemistry, (deuterated) thioformaldehyde is mainly formed through gas-phase reactions (double-replacement and neutral-neutral displacement reactions), while surface chemistry plays an important role as a destruction mechanism.
Magnetism, rotation, and nonthermal emission in cool stars
Authors: Reiners A. , Shulyak D. , Käpylä P. J. , Ribas I. , Nagel E. , Zechmeister M. , Caballero J. A. , Shan Y. , Fuhrmeister B. , Quirrenbach A. , Amado P. J. , Montes D. , Jeffers S. V. , Azzaro M. , Béjar V. J. S. , Chaturvedi P. , Henning Th. , Kürster M. , Pallé E.
Published: April 2022

Stellar dynamos generate magnetic fields that are of fundamental importance to the variability and evolution of Sun-like and low-mass stars, and for the development of their planetary systems. As a key to understanding stellar dynamos, empirical relations between stellar parameters and magnetic fields are required for comparison to ab initio predictions from dynamo models. We report measurements of surface-average magnetic fields in 292 M dwarfs from a comparison with radiative transfer calculations; for 260 of them, this is the first measurement of this kind. Our data were obtained from more than 15 000 high-resolution spectra taken during the CARMENES project. They reveal a relation between average field strength, ⟨B⟩, and Rossby number,Ro, resembling the well-studied rotation–activity relation. Among the slowly rotating stars, we find that magnetic flux, ΦB, is proportional to rotation period,P, and among the rapidly rotating stars that average surface fields do not grow significantly beyond the level set by the available kinetic energy. Furthermore, we find close relations between nonthermal coronal X-ray emission, chromospheric Hαand Ca H&K emission, and magnetic flux. Taken together, these relations demonstrate empirically that the rotation–activity relation can be traced back to a dependence of the magnetic dynamo on rotation. We advocate the picture that the magnetic dynamo generates magnetic flux on the stellar surface proportional to rotation rate with a saturation limit set by the available kinetic energy, and we provide relations for average field strengths and nonthermal emission that are independent of the choice of the convective turnover time. We also find that Ca H&K emission saturates at average field strengths of ⟨B⟩≈800 G while Hαand X-ray emission grow further with stronger fields in the more rapidly rotating stars. This is in conflict with the coronal stripping scenario predicting that in the most rapidly rotating stars coronal plasma would be cooled to chromospheric temperatures.
Aerosol assisted atmospheric pressure plasma jet for a high deposition rate of silica-like thin films
Authors: Magnan Romain , Clergereaux Richard , Villeneuve-Faure Christina , Lantin Benoît , Carnide Guillaume , Raynaud Patrice , Naude Nicolas
Published: April 2022

This paper investigated thin films deposition processes of silica-like based on the injection of liquid droplets in Atmospheric Pressure Plasma Jet–APPJ operated in open air. An aerosol of hexamethyldisilane is produced by a syringe-pump and injected in a nitrogen post-discharge for different liquid precursor and carrier gas flow rates. For high carrier gas flow, this process enables to form silica-like without addition of oxygen in the plasma phase. Furthermore, this process offers a thin film dynamic deposition rate from 500 to 1400 nm.m.min−1 depending on the carrier gas flow and the film structure departs from silica-like to organosilicon layers for the lowest flow rates. These evolutions are attributed to plasma–droplets interactions related to the transport of droplets, the evaporation of liquid and plasma polymerization.
Upwelling coherent backscatter plumes observed with ionosondes in low-latitude region
Authors: Jiang Chunhua , Wei Lehui , Yokoyama Tatsuhiro , Xu Jiyao , Wu Kun , Yuan Wei , Liu Jing , Liu Tongxin , Yang Guobin , Zhao Zhengyu
Published: April 2022

Investigations of upwelling backscatter plumes are mostly from observations of VHF radars. This study reports the first observation of upwelling backscatter plumes (backscatter echoes beyond the critical frequency of the F2 layer, foF2) recorded by ionosondes at low latitudes on 13 March 2015. With a pair of ionosondes (Puer, 22.7° N, 101.05° E, Dip Lat 12.9° N, and Chiang Mai, 18.76° N, 98.93° E, Dip Lat 9.04° N), Swarm satellites flying side-by-side (longitudinal separation of about 1.4°, about 150 km), and an all-sky imager (25° N, 104° E, Dip Lat 15.1° N), the evolution of plasma bubbles is presented in this study. Observations show that ionosonde backscatter plumes originating from a local-scale upwelling could be observed. In addition, this study also reported ionosonde backscatter plumes from other regions with approaching and receding characteristics. Results show that characteristics of backscatter plumes with ionosondes are consistent with observations from VHF radars. It suggests that ionosonde backscatter plumes might also be used to study the characteristics of upwelling backscatter plumes.
Roaming dynamics of H+C2D2 reaction on fundamental-invariant neural network potential energy surface
Authors: Bai Yuyao , Fu Yan-Lin , Han Yong-Chang , Fu Bina , Zhang Dong H.
Published: April 2022

We performed extensive quasiclassical trajectory calculations for the H+C2D2→HD+C2D/D2+C2H reaction based on a recently developed, global and accurate potential energy surface by the fundamental-invariant neural network method. The direct abstraction pathway plays a minor role in the overall reactivity, which can be negligible as compared with the roaming pathways. The acetylene-facilitated roaming pathway dominates the reactivity, with very small contributions from the vinylidene-facilitated roaming. Although the roaming pathways proceed via the short-lived or long-lived complex forming process, the computed branching ratio of product HD to D2 is not far away from 2:1, implying roaming dynamics for this reaction is mainly contributed from the long-lived complex-forming process. The resulting angular distributions for the two product channels are also quite different. These computational results give valuable insights into the significance and isotope effects of roaming dynamics in the biomolecular reactions.
Study on the shear performance of new type interpenetrating composite plate connector
Authors: Wang Xiaoxing , Zhou Yu , Li Jingli , Li Huijian
Published: April 2022

A new kind of epoxy resin/foam nickel–iron plate connector is introduced. This kind of interpenetrating composite connector has approximate thermal insulation performance of the resin, good mechanical properties, and easy manufacture and production. This paper studied the shear performance of the connector at the elastic–plastic stage, which was the basis important performance of the connector to be widely used. Three groups of specimens made of single-layer foam nickel–iron plate and three groups of specimens made of double-layer foam nickel–iron plate were tested and analyzed by finite element simulation. The results showed that the plate connector had better shear strength. The failure mode of plate specimens was the typical bending shear failure, and finally, the web buckling occurred in the compression zone. The bearing capacity of the specimen was positively correlated with the thickness of the specimen and the material properties of the matrix phase.
The effect of magnetic field on diffusion and drift of electrons in helium and xenon
Authors: Maiorov S. A. , Kodanova S. K. , Bastykova N. Kh. , Golyatina R. I. , Ramazanov T. S. , Omiraliyeva G. K.
Published: April 2022

In this work, kinetic characteristics of the electron drift are calculated by the Monte Carlo method in two inert gases (He and Xe) at an electric field strength E/N = 30 100 Td, and a magnetic field induction up to 1 T at a gas density of 1017 atoms per cm3. The results of calculations of the electron drift characteristics in helium and xenon in constant and uniform electric and magnetic fields are presented. The methods of numerical simulation are used to obtain the main characteristics of the electron drift and the diffusion coefficients. It is shown that accounting for the magnetic field leads to a decrease in the drift velocity and mean energy of the electrons. The results of the calculation can be used for the analysis of experimental data on electron drift and diffusion in crossed electric and magnetic fields.
Probing electromagnetic wave energy with an in-series assembly of thermoelectric devices
Authors: Rybarczyk R. Joseph , Federick Alexandria E. D. , Kokhan Oleksandr , Luckay Ryan , Scarel Giovanna
Published: April 2022

We study the interaction of radio waves, microwaves, and infrared laser light of power P and period τ with a macroscopic thermoelectric (TEC) device-based detector and probe the energy Pτ as being the energy of these electromagnetic (EM) waves. Our detectors are in-series assemblies of TEC devices. We treat these detectors as equivalent to capacitors and/or inductors. The energy Pτ enables characterizing detector’s parameters, such as equivalent capacitance, inductance, resistance, responsivities, effective power, and efficiency. Through various scaling procedures, Pτ also aids in determining the power P of the EM waves. We compare the performance of our detectors with that of other TEC devices and with radio- and microwave-sensitive devices reported in the current literature, such as spin–orbit torque and spin–torque oscillator devices, heterojunction backward tunnel diodes, and Schottky diodes. We observe that the performance of our detectors is inferior. However, the order of magnitude of our detector’s parameters is in reasonable agreement with those of other TEC and non-TEC devices. We conclude that TEC devices can be used to detect radio waves and that Pτ effectively captures the energy of the EM waves. Considering Pτ as the EM wave’s energy offers a classical approach to the interaction of EM waves with matter in which photons are not involved. With the EM wave’s energy depending upon two variables (P and τ), a similar response could be produced by, e.g., radio waves and visible light, leading to interesting consequences that we briefly outline.
Trifurcate structure of oxygen band EMIC waves excited in a warm magnetospheric plasma
Authors: Wang Zhiqiang , Xia Lingjian , Gao Ke , Sun Kang
Published: April 2022

Applying linear dispersion theory to a warm collisionless plasma, we investigate the effect of hot ion composition on electromagnetic ion cyclotron (EMIC) wave generation. The growth rate of oxygen band waves can divide into three components if hot anisotropic heavy ions are included. Their wave frequencies (0.05 ΩH+, 0.03 ΩH+, and 0.01 ΩH+) are sorted in relation to the cyclotron frequencies of H+, He+, and O+ ions (ΩH+, ΩH+/4, and ΩH+/16). The three sub-bands within the oxygen band form an unusual trifurcate structure of growth rate. A link between the three sub-bands and three hot species has been definitively established. That is to say, hot H+, He+, and O+ ions are responsible for the generation of sub-bands. The unstable frequencies of oxygen band waves are directly modulated by the actual composition of magnetospheric ions. The largest growth can arise between the extremely low frequency and the gyrofrequency of O+ (ΩO+). When O+ ions become the dominant hot component during the storm phase, oxygen waves can be generated at much lower frequencies than ΩO+. We perform a parametric study of oxygen sub-band generation in the magnetosphere by using a statistical survey of the plasma composition measured by the Van Allen Probes. The trifurcate structure of growth rate appears at wide L shells from the outer plasmasphere to the geostationary orbit. The new findings demonstrate that wave structures in the oxygen band are more complex than the hydrogen and helium bands. This may provide insight into the nature of the EMIC instability.
Charge state distributions in dense plasmas
Authors: White J. R. , Johns W. , Fontes C. J. , Gill N. M. , Shaffer N. R. , Starrett C. E.
Published: April 2022

Charge state distributions in hot, dense plasmas are a key ingredient in the calculation of spectral quantities like the opacity. However, they are challenging to calculate, as models like Saha–Boltzmann become unreliable for dense, quantum plasmas. Here, we present a new variational model for the charge state distribution, along with a simple model for the energy of the configurations that includes the orbital relaxation effect. Comparison with other methods reveals generally good agreement with average atom-based calculations, the breakdown of the Saha–Boltzmann method, and mixed agreement with a chemical model. We conclude that the new model gives a relatively inexpensive, but reasonably high fidelity method of calculating the charge state distribution in hot dense plasmas, in local thermodynamic equilibrium.
Elastic behavior of metal-assisted etched Si/SiGe superlattice nanowires containing dislocations
Authors: Buczek (née Geyer) Nadine , Hanke Michael , Buczek Pawel , Dubslaff Martin , Tonkikh Alexander A. , Fuhrmann Bodo , Leipner Hartmut S.
Published: April 2022

We systematically investigate structural parameters, such as shape, size, elastic strain, and relaxations, of metal-assisted etched vertically modulated Si/SiGe superlattice nanowires by using electron microscopy, synchrotron-based x-ray diffraction, and numerical linear elasticity theory. A vertical Si/Ge superlattice with atomically flat interfaces is grown by using molecular beam epitaxy on Si-buffered Si(001) substrates. The lattice constants for Si and Ge are 5.43 and 5.66 Å, respectively, which indicate a lattice mismatch of 4.2%. This results in a strained layer in the boundary between Si and Ge leading to dislocations. These substrates serve as the starting material for nanostructuring the surface by using metal-assisted etching. It is shown that the high quality crystalline structure is preserved in the fabrication process, while the lattice mismatch is partially relieved by dislocation formation. Despite this highly effective relaxation path, dislocations present in the parent superlattice do not vanish upon nanostructuring for wires with diameters of down to at least 80 nm. We relate these observations to the applicability of silicon-based nanowires for high-performance thermoelectric generators.
Lawrence Livermore achieves a burning plasma in the lab
Authors: Wilson R. Mark
Published: April 2022

In that regime, fusion reactions are the plasma’s primary source of heating.
Hendrik Lorentz, Robert Millikan, and interwar reconciliation
Authors: Delft Dirk van
Published: April 2022

World War I tore apart a close-knit international physics community. During the interwar period, two famous physicists attempted to repair those shattered bonds.
Inhibitory effect induced by fractional Gaussian noise in neuronal system
Authors: Li Zhi-Kun , Li Dong-Xi
Published: April 2022

We discover a phenomenon of inhibition effect induced by fractional Gaussian noise in a neuronal system. Firstly, essential properties of fractional Brownian motion (fBm) and generation of fractional Gaussian noise (fGn) are presented, and representative sample paths of fBm and corresponding spectral density of fGn are discussed at different Hurst indexes. Next, we consider the effect of fGn on neuronal firing, and observe that neuronal firing decreases first and then increases with increasing noise intensity and Hurst index of fGn by studying the time series evolution. To further quantify the inhibitory effect of fGn, by introducing the average discharge rate, we investigate the effects of noise and external current on neuronal firing, and find the occurrence of inhibitory effect about noise intensity and Hurst index of fGn at a certain level of current. Moreover, the inhibition effect is not easy to occur when the noise intensity and Hurst index are too large or too small. In view of opposite action mechanism compared with stochastic resonance, this suppression phenomenon is called inverse stochastic resonance (ISR). Finally, the inhibitory effect induced by fGn is further verified based on the inter-spike intervals (ISIs) in the neuronal system. Our work lays a solid foundation for future study of non-Gaussian-type noise on neuronal systems.
Temporal response of laminated graded-bandgap GaAs-based photocathode with distributed Bragg reflection structure: Model and simulation
Authors: Wang Zi-Heng , Zhang Yi-Jun , Li Shi-Man , Li Shan , Zhan Jing-Jing , Qian Yun-Sheng , Shi Feng , Cheng Hong-Chang , Jiao Gang-Cheng , Zeng Yu-Gang
Published: April 2022

To describe the dynamic response characteristics of the laminated graded-bandgap GaAs-based photocathode with distributed Bragg reflection structure, a general theoretical temporal response model is deduced by combining the unsteady continuity equation and numerical calculation method. Through the model, the contribution of the distribution Bragg reflection structure and graded-bandgap emission layer to the temporal response are investigated. Meanwhile, the relationships between the temporal response characteristics of the laminated GaAs-based photocathode and different structural parameters are also analyzed, including average electron decay time, emission layer thickness, and incident light wavelength. It is found that the introduction of distribution Bragg reflection (DBR) layer solves the discrepancy between the absorption capability of the emission layer and the temporal response. Moreover, the distributed Bragg reflection layer can improve the time response by optimizing the initial photoelectron distribution. The improvement effect of the DBR layer on the temporal response is enhanced with the emission layer thickness decreasing or the incident light wavelength increasing. These results explain the effect of the DBR layer of the photocathode on the dynamic characteristics, which can offer a new insight into the dynamic research of GaAs-based photocathode.
Exponential sine chaotification model for enhancing chaos and its hardware implementation
Authors: Wang Rui , Li Meng-Yang , Luo Hai-Jun
Published: April 2022

Chaotic systems have been intensively studied for their roles in many applications, such as cryptography, secure communications, nonlinear controls, etc. However, the limited complexity of existing chaotic systems weakens chaos-based practical applications. Designing chaotic maps with high complexity is attractive. This paper proposes the exponential sine chaotification model (ESCM), a method of using the exponential sine function as a nonlinear transform model, to enhance the complexity of chaotic maps. To verify the performance of the ESCM, we firstly demonstrated it through theoretical analysis. Then, to exhibit the high efficiency and usability of ESCM, we applied ESCM to one-dimensional (1D) and multi-dimensional (MD) chaotic systems. The effects were examined by the Lyapunov exponent and it was found that enhanced chaotic maps have much more complicated dynamic behaviors compared to their originals. To validate the simplicity of ESCM in hardware implementation, we simulated three enhanced chaotic maps using a digital signal processor (DSP). To explore the ESCM in practical application, we applied ESCM to image encryption. The results verified that the ESCM can make previous chaos maps competitive for usage in image encryption.
Spectroscopic study of B2Σ+–X1
2Π1/2 transition of electron electric dipole moment candidate PbF
Authors: Chen Ben , Chen Yi-Ni , Pan Jia-Nuan , Yin Jian-Ping , Wang Hai-Ling
Published: April 2022

PbF, a valuable candidate for measuring the electron electric dipole moment (eEDM), is of great significance in measuring its spectrum and deriving its molecular constants in experiment. In the present work, the rovibronic spectrum of the B2Σ+–X1
2Π1/2 transition of PbF in a wavelength range of 260 nm–285 nm is studied by the laser ablation/laser induced fluorescence method. The molecular parameters of the X1
2Π1/2 (v″ = 0) and B2Σ+ (v′ = 0, 1) states are derived from the recorded spectra of the (0, 0) and (1, 0) bands of the B2Σ+–X1
2Π1/2 transition. Also, the Franck–Condon factors (FCFs) of the transitions between the B2Σ+ and X1
2Π1/2 states are calculated by the RKR/LEVEL method and the Morse potential method, respectively.
A Review of Majorana fermions and the laws of form
Authors: Kauffman Louis H
Published: April 2022

This review article is an exploration of G. Spencer-Brown’s well-known work on the Laws of Form and its relationship to physical science, focusing on correspondence with Majorana fermions.