bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiwavelength observations of Swift J0243.6+6124 from 2017 to 2022
Authors: Liu Wei , Yan Jingzhi , Reig Pablo , Wang Xiaofeng , Xiao Guangcheng , Lin Han , Zhang Xinhan , Sai Hanna , Chen Zhihao , Yan Shengyu , Liu Qingzhong
Published: July 2022

Context.Swift J0243.6+6124 is a high-mass X-ray binary that went into a giant X-ray outburst in 2017. During this event, the X-ray luminosity reached the highest value ever measured in a galactic Be/X-ray binary.

Aims. Our aim is to study the long-term variability of Swift J0243.6+6124 after the 2017 major X-ray outburst.

Methods. We have obtained optical spectroscopy and photometry data during four years after the event. The long-term photometric light curve and the equivalent widths of the Hα and He I λ6678 lines were used to monitor the state of the Be star’s circumstellar disk. The Hα line profiles show evidence for V/R variability that was accounted for by fitting the Hα spectral line profile with two Gaussian functions. We divided our data into three phases according to the intensity of the X-ray, optical, and infrared emission.

Results. Phase I covers the rise and decay of the giant X-ray outburst that took place in October–November 2017. We interpret phase II as the dissipation of the Be star’s equatorial disk and phase III as its recovery. The timescale of a complete formation and dissipation process is about 1250 days. The epoch when the dissipation process stopped and the reformation period began is estimated to be around MJD 58530. We find a delay of ∼100–200 days between the minimum of the optical or infrared intensity and the strength of the Hα line after the X-ray outburst, which may indicate that the dissipation of the disk begins from the inner parts. The motion of the density perturbation inside the disk is prograde, with a V/R quasi-period of about four years. The source shows a positive correlation in the (B − V) color index versus V-band magnitude diagram, which implies that the system is seen at a small or moderate inclination angle.

Conclusions. Despite the super-Eddington X-ray luminosity during the outburst, the subsequent pattern of long-term optical and IR variability of Swift J0243.6+6124 is typical of Be/X-ray binaries.
The ionizing and heating power of ultraluminous X-ray sources under the geometrical beaming model
Authors: Kovlakas K. , Fragos T. , Schaerer D. , Mesinger A.
Published: July 2022

While there is now a consensus that X-ray binaries (XRBs) are the dominant X-ray sources in the early Universe and play a significant role during the epoch of heating of the intergalactic medium (IGM), recent studies report contradicting results regarding their contribution in the nebular emission of local Universe galaxies. Ultraluminous X-ray sources (ULXs), which dominate the X-ray budget of normal galaxies, may be important interstellar-medium (ISM) ionizing sources. However, their output in the extreme-ultraviolet (EUV) and soft X-ray part of the spectrum remains observationally unconstrained. In this paper, we predict the ionizing and heating power from ULX populations under the geometrical beaming scenario, and three models describing the emission from super-critical accretion disks. We find that our theoretical spectra for ULX populations cannot (can) explain the He II (Ne V) emission observed in some galaxies, with their contribution being less (more) important than the underlying stellar population. Stochastic fluctuations in the number of ULXs may allow for equal contributions in the He II emission, in a fraction of galaxies. We provide average spectra of ULX populations as an input to local, and early-Universe studies. We find that the soft X-ray emission arising from super-critical accretion is significant for the heating of the IGM, and consistent with recent constraints from the 21-cm cosmic signal. Based on the dependence on the adopted compact-object (CO) mass and accretion model, we encourage efforts in modeling ULX spectra via simulations, and their combination with detailed binary population synthesis models.
The economic value of ecosystem conservation: a discrete-choice experiment at the Taravo Wild River in Corsica, France
Authors: Hernandez Daniel , da Costa Pascal
Published: July 2022

This article contributes to the literature on non-market evaluation methods, applied to ecosystem services. The ecological status of the Taravo River is currently under threat by human activities. In this context, we value some of the ecosystem services provided at the Taravo River Basin using a stated-preference approach. Four different econometric estimations were considered for this discrete-choice experiment. On average, respondents are willing to pay 128 euros per year for the enhancement of the ecosystem services selected. This result is in line with those obtained in recent contributions that have applied similar approaches. Beyond this average, this article conducts a spatial analysis to confirm the different willingness to pay on the territory (upper versus lower Taravo).
Combined effects of urbanization and longitudinal disruptions in riparian and in-stream habitat on water quality of a prairie stream
Authors: Bertora Andrea , Grosman Fabián , Sanzano Pablo , Rosso Juan J.
Published: July 2022

Local habitat and riparian modifications imposed by surrounding land use drastically impact the water quality of streams. However, whether these effects could still be discernible when the watercourse also receives urbanization effluents has not been fully explored. We evaluated the water quality of a Neotropical prairie stream exposed to urbanization and explored the role of downstream patches of different surrounding land uses (cropland and livestock) in further regulating water quality. Forty-two variables of water quality, habitat structure and riparian condition were measured at four reaches of the Langueyú stream. Significant differences in water quality were observed. Water conductivity, dissolved oxygen, salinity, dissolved solids, chloride, inorganic nitrogen and bacteriological loads displayed a continuum of recovery from the urban reach. Indeed, almost 24 percent of the total variation in water quality was explained by the longitudinal arrangement of sites. Alternatively, pH, phosphorous, suspended solids and chemical oxygen demand showed a disruption in this continuum of recovery and were highly related with local aspects of habitat structure and riparian conditions imposed by cropland and livestock. Key aspects of effluent treatment, riparian integrity and in-stream habitat must be addressed within a comprehensive social context in order to design sustainable management of fluvial urbanised ecosystems.
Lake-wide mapping of littoral habitat using underwater videography
Authors: Olden Julian D. , Miler Oliver , Bijaye Alexander
Published: July 2022

Littoral zones − referring to benthic areas above the light compensation depth − provide numerous ecosystem functions, including mediating light, temperature, and nutrient dynamics, and supporting important foraging and refuge areas for macroinvertebrates, fishes and water birds. Habitat assessments of littoral zones remain fundamental to lake and fisheries management, however traditional field surveys are time-intensive and limited in their spatial extent, whereas desktop evaluations using remote sensing and aerial imagery are cost prohibitive and require considerable data processing expertise. In light of these challenges, this study demonstrated the ability to use simple, cost-effective underwater videography to conduct lake-wide spatially-continuous assessments of littoral habitat. For lakes across a gradient of shoreline and riparian development in northwestern United States, we map the areal coverage of macrophytes, coarse woody habitat, bottom substrates, and artificial structures in littoral zones. Underwater videography represents a relevant tool for environmental monitoring because it allows for the estimation of littoral habitats at fine spatial grains across broad spatial extents. Data can also be obtained rapidly and at relatively low cost, providing a permanent record of habitat conditions that can used to monitor trends over time.
Tuberculous osteomyelitis of the mandible impersonating dentoalveolar abscess: a case report
Authors: Popli Harsha , Gupta Ambika , Lonyal Jatin , Singh Aarti
Published: July 2022

Introduction: Tuberculosis (TB) affects 8 million new people every year, with developing countries under its strong clout. Although tuberculosis can affect any part of the body involving both soft and hard tissues; such an occurrence in the maxillofacial bones in the form of tuberculous osteomyelitis is relatively rare. Due to the rarity of the lesion and lack of sufficient documentation, its incidence can be expected to be more than what has been reported so far. Observation: So, here is a case of a 21-year-old male who presented with pain and swelling on the mandible, diagnosed as tuberculous osteomyelitis after an initial diagnosis of dentoalveolar abscess. Conclusion: As dentists and as oral medicine practitioners, it is of utmost importance for us to be aware about uncommon diseases affecting the jaws such as tuberculous osteomyelitis, which tend to mimic dental infections in some cases to prevent misdiagnosis and provide holistic care to the patient.
Fetal Cardiovascular MRI – A Systemic Review of the Literature: Challenges, New Technical Developments, and Perspectives
Authors: Knapp Janine , Tavares de Sousa Manuela , Schönnagel Björn P.
Published: July 2022

Background Fetal magnetic resonance imaging (MRI) has become a valuable adjunct to ultrasound in the prenatal diagnosis of congenital pathologies of the central nervous system, thorax, and abdomen. Fetal cardiovascular magnetic resonance (CMR) was limited, mainly by the lack of cardiac gating, and has only recently evolved due to technical developments.

Method A literature search was performed on PubMed, focusing on technical advancements to perform fetal CMR. In total, 20 publications on cardiac gating techniques in the human fetus were analyzed.

Results Fetal MRI is a safe imaging method with no developmental impairments found to be associated with in utero exposure to MRI. Fetal CMR is challenging due to general drawbacks (e. g., fetal motion) and specific limitations such as the difficulty to generate a cardiac gating signal to achieve high spatiotemporal resolution. Promising technical advancements include new methods for fetal cardiac gating, based on novel post-processing approaches and an external hardware device, as well as motion compensation and acceleration techniques.

Conclusion Newly developed direct and indirect gating approaches were successfully applied to achieve high-quality morphologic and functional imaging as well as quantitative assessment of fetal hemodynamics in research settings. In cases when prenatal echocardiography is limited, e. g., by an unfavorable fetal position in utero, or when its results are inconclusive, fetal CMR could potentially serve as a valuable adjunct in the prenatal assessment of congenital cardiovascular malformations. However, sufficient data on the diagnostic performance and clinical benefit of new fetal CMR techniques is still lacking.

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Citation Format
Summary of Bifurcation Stenting Strategies and Outcomes in Women
Authors: Alasnag Mirvat , Dakhil Zainab , Sukmawati Indah , Rao Sarita , Hussain Shazia T.
Published: July 2022

Several studies have examined the efficacy of drug-eluting stents in acute and chronic coronary syndromes and demonstrated benefit in both men and women. However, the effect of gender on percutaneous coronary intervention (PCI) outcomes in more complex disease including bifurcation disease is less well-known. In particular, a two-stent or provisional strategy, for both left Main and non-Left Main bifurcation lesions, has been variable across the different studies. In addition, there is a notable geographic preference whereby a stepwise provisional strategy with culotte as a bailout technique is preferred in Europe while in Asia there is a predilection to DK Crush for a 2-stent strategy. Many of these trials, however, are underpowered to conduct subgroup analysis for outcomes in women. To date, the evidence suggests women have better outcomes with coronary artery bypass grafting in complex disease. The higher events in women undergoing PCI are largely driven by bleeding. Studies dedicated to evaluating outcomes after complex revascularization in women are desperately needed with long-term follow-up. This review examines the current landmark trials as they pertain to outcomes in women.
Persistent homology distinguishes image features from noise
Authors: Piccone Ashley
Published: July 2022

The technique may reduce the computing power necessary to automatically identify dark solitons in Bose-Einstein condensates.
Theoretical and experimental study on coupling characteristics of double-sided immersion cylindrical shells with arbitrary boundary
Authors: Yu Anbin , Zhao Yinglong , Jin Qeqing
Published: July 2022

Based on the wave propagation method and improved Fourier series, the coupled vibration model of double-sided immersion (DI) cylindrical shell under arbitrary boundary conditions is established, and its coupled vibration characteristics are solved. The coupling vibration characteristic experiment of a cylindrical shell under the DI condition is carried out for the first time. The calculated natural frequency and vibration acceleration are compared with the model experimental results, which not only verifies the reliability of the theoretical method but also proves the effectiveness of the experimental results. Finally, the coupled vibration characteristics of DI cylindrical shells with arbitrary boundary conditions are analyzed. The results show that the natural frequency and acceleration of underwater immersed cylindrical shells are consistent with those of liquid filling cylindrical shells. The natural frequency and peak acceleration of the single-sided submerged cylindrical shell are greater than that of the DI cylindrical shell. The spring stiffness at both ends of the DI cylindrical shell can be divided into three sections: free boundary, elastic boundary, and rigid boundary.
Interband cascade infrared photodetectors based on Ga-free InAs/InAsSb superlattice absorbers
Authors: Bader A. , Rothmayr F. , Khan N. , Jabeen F. , Koeth J. , Höfling S. , Hartmann F.
Published: July 2022

We present an interband cascade infrared photodetector based on Ga-free type-II superlattice absorbers. Substituting the more standard InAs/GaSb superlattice for a Ga-free superlattice with InAs/InAsSb requires an inverted carrier extraction path. A hole-ladder in the electron-barrier, instead of an electron-ladder in the hole-barrier, is employed to achieve photovoltaic operation. At elevated temperatures, seven negative-differential-conductance (NDC) regions are observed that arise from electrons tunneling through the electron barriers of the seven cascade stages. The detector operates in the photovoltaic mode at room temperature with a cutoff wavelength of 8.5 μm. At the NDC regions, the device features responsivity peaks under laser illumination reaching 0.45 A/W at room temperature at λ = 5.27 μm. This exceeds its highest measured low-temperature value of 0.22 A/W at this wavelength by a factor of 2.
Impedance spectroscopy of ferroelectrics: The domain wall pinning element
Authors: Becker Maximilian T. , Burkhardt Claus J. , Kleiner Reinhold , Koelle Dieter
Published: July 2022

We introduce an equivalent-circuit element based on the theory of interface pinning in random systems to analyze the contribution of domain wall motion below the coercive field to the impedance of a ferroelectric, as a function of amplitude E0 and frequency f of an applied ac electric field. We demonstrate our model on a bulk PbZrxTi1−xO3 (PZT) reference sample and then investigate capacitor stacks, containing ferroelectric 0.5(Ba0.7Ca0.3)TiO3–0.5Ba(Zr0.2Ti0.8)O3 (BCZT) thin films, epitaxially grown by pulsed laser deposition on Nb-doped SrTiO3 single crystal substrates and covered with Au electrodes. Impedance spectra from f=10 Hz to 1 MHz were collected at different E0. Deconvolution of the spectra is achieved by fitting the measured impedance with an equivalent-circuit model of the capacitor stacks, and we extract for E0=2.5 kV/cm, a frequency-dependent permittivity of εr′(f)=458+7.3ln⁡(1Hz/2πf) for the BCZT films from the obtained fit parameters. From an extended Rayleigh analysis, we obtain a coupling strength of 0.187 cm/kV between dielectric nonlinearity and dielectric dispersion in the BCZT films and identify different domain-wall-motion regimes. Finally, we construct a schematic diagram of the different domain-wall-motion regimes and discuss the corresponding domain-wall dynamics. Our approach can be utilized to replace purely phenomenological constant phase elements (CPEs) in modeling the impedance response of ferroelectrics and extracting material properties.
Dark soliton detection using persistent homology
Authors: Leykam Daniel , Rondón Irving , Angelakis Dimitris G.
Published: July 2022

Classifying images often requires manual identification of qualitative features. Machine learning approaches including convolutional neural networks can achieve accuracy comparable to human classifiers but require extensive data and computational resources to train. We show how a topological data analysis technique, persistent homology, can be used to rapidly and reliably identify qualitative features in experimental image data. The identified features can be used as inputs to simple supervised machine learning models, such as logistic regression models, which are easier to train. As an example, we consider the identification of dark solitons using a dataset of 6257 labeled atomic Bose–Einstein condensate density images.
Tunable photochemical deposition of silver nanostructures on layered ferroelectric CuInP2S6
Authors: Kong Fanyi , Zhang Lei , Cong Tianze , Wu Zhiwei , Liu Kun , Sun Changsen , Pan Lujun , Li Dawei
Published: July 2022

Two-dimensional layered ferroelectric materials, such as CuInP2S6 (CIPS), are promising candidates for novel and high-performance photocatalysts, owing to their ultrathin layer thickness, strong interlayer coupling, and intrinsic spontaneous polarization, while how to control the photocatalytic activity in layered CIPS remains unexplored. In this work, we report for the first time, the photocatalytic activity of ferroelectric CIPS for the chemical deposition of silver nanostructures (AgNSs). The results show that the shape and spatial distribution of AgNSs on CIPS are tunable by controlling layer thickness, environmental temperature, and light wavelength. The ferroelectric polarization in CIPS plays a critical role in tunable AgNS photodeposition, as evidenced by layer thickness and temperature dependence experiments. We further reveal that AgNS photodeposition process starts from active site creation, selective nanoparticle nucleation/aggregation, to continuous film formation. Moreover, AgNS/CIPS heterostructures prepared by photodeposition exhibit excellent resistance switching behavior and good surface enhancement Raman Scattering activity. Our findings provide new insight into the photocatalytic activity of layered ferroelectrics and offer a new material platform for advanced functional device applications in smart memristors and enhanced chemical sensors.
Self-adaptive real-time time-dependent density functional theory for x-ray absorptions
Authors: Ye Linfeng , Wang Hao , Zhang Yong , Liu Wenjian
Published: July 2022

Real-time time-dependent density functional theory (RT-TDDFT) can, in principle, access the whole absorption spectrum of a many-electron system exposed to a narrow pulse. However, this requires an accurate and efficient propagator for the numerical integration of the time-dependent Kohn–Sham equation. While a low-order time propagator is already sufficient for the low-lying valence absorption spectra, it is no longer the case for the x-ray absorption spectroscopy (XAS) of systems composed even only of light elements, for which the use of a high-order propagator is indispensable. It is then crucial to choose a largest possible time step and a shortest possible simulation time so as to minimize the computational cost. To this end, we propose here a robust AutoPST approach to determine automatically (Auto) the propagator (P), step (S), and time (T) for relativistic RT-TDDFT simulations of XAS.
Artificial Intelligence Methods for Fault Diagnosis in Centrifugal Pumps
Authors: Al Tobi Maamar Ali Saud , Bevan Geraint , Okedu Kenneth
Published: July 2022

This important book offers a foundation for use of artificial intelligence (AI) in fault diagnosis and classification for centrifugal pumps. It outlines methods for operators to identify and classify faults that are not easily detectable using traditional techniques like time domain and frequency domain methods. It brings together different AI approaches that are integrated with Wavelet Transform (WT) and Genetic Algorithm (GA) into a single reference—making advanced diagnostic methods accessible to engineers who may not have a computer science background.

Covering a wide range of AI applications for mechanical systems, the book:Advances readers from description of the problem to application of AI methods for diagnosticsOutlines ways for operators to identify and classify faults that are not easily detectable using traditional techniquesOffers new data from a novel experimental rig not previously available

Artificial Intelligence Methods for Fault Diagnosis in Centrifugal Pumps is an ideal reference for academics, engineers, and industry professionals working in plant and operations maintenance. Undergraduate and graduate students of artificial intelligence systems will find this an invaluable reference.
Extensional Rheology of Unentangled Linear Polymer Melts
Authors: Watanabe Hiroshi , Hassager Ole , Matsumiya Yumi , Huang Qian
Published: July 2022

Under fast extensional flow, polymer chains are strongly oriented/stretched to exhibit highly nonlinear rheology. Strain-rate hardening due to the finite extensible nonlinear elasticity (FENE) was established several decades ago for entangled branch-on-branch polymers, and molecular models incorporating this FENE effect were developed on the basis of the concept of topological constraint for motion of mutually uncrossable chains. Nevertheless, for entangled linear polymers, recent experiments revealed that the hardening occurs in solutions but not in melts having the same entanglement density, which led to improvement of the models through incorporation of segmental friction (ζ) reduction in a stretched/co-aligned environment; ζ-reduction is absent in solutions because solvent molecules offer an isotropic environment for the polymer segments. On the basis of this knowledge, very recent studies focused on the extensional nonlinearities of the simplest material, unentangled melts of monodisperse linear polymers, to confirm that ζ-reduction occurs also in the absence of entanglement. Those studies further suggested an importance of flow-induced changes of the thermal Brownian force in addition to the FENE effect and ζ-reduction. This chapter outlines a theoretical framework needed to describe/understand these molecular aspects of unentangled melts and further discusses its consequence to the nonlinear rheology of entangled polymers
Lung Surfactant Dilatational Rheology and Potential Effects on Lung Stability
Authors: Barman Sourav , Iasella Steven , Ciutara Clara , Valtierrez-Gaytan Cain , Zasadzinski Joseph
Published: July 2022

Acute respiratory distress syndrome (ARDS) is a diffuse, inflammatory lung disease characterized by increased vascular permeability, decreased lung compliance, and loss of aerated tissue affecting 200,000 in.the US annually with 40% mortality. COVID-19 infections have significantly increased these numbers over the past two years with a mortality rate of nearly 70%. The mechanisms through which ARDS arises and how host factors confer an increased risk of developing severe disease remain unclear. It is known that inflammation due to underlying disease is linked to ARDS progression and severity. Phospholipase A2 catalyzed degradation of pathogen phospholipids to soluble lysolipids and free fatty acids can lead to a mechanical lung instability known as the ‘Laplace Instability’ by replacing healthy lung surfactant at the air-water interface. The intra-alveolar pressure is increased by ΔP = 2γ/R; ΔP is higher in alveoli with smaller radii, R, than larger alveoli if γ, the surface tension, is constant. This would cause smaller alveoli to deflate and fill with fluid, while the larger alveolar become distended, both symptoms of ARDS. To prevent this, the surface tension must decrease with decreasing alveolar radius such that 2E* (ω) − γ > 0 in which E* (ω) = A(ω) (∂γ/∂A) is the dilatational modulus. For healthy lung surfactant 2E* (ω) − γ > 0 and the lung is stable. However, during inflammation, lysolipid concentrations increase by orders of magnitude in the alveolar fluids. We show that lysopalmitoylphosphatidylcholine concentrations above its critical micelle concentration (CMC) cause E> (ω) of lung surfactant monolayers to decrease dramatically leading to 2E* (ω)−γ ≤ 0 at breathing frequencies, which can lead to the Laplace Instability and compromise uniform lung inflation. Theoretical models show E* decreases due to diffusive exchange of lysolipids between the monolayer and the micelles in the adjacent fluid. Surfactant adsorption to a clean interface as well as surfactant dilatational properties can be correlated with equilibrium surface concentration vs bulk concentration data using fundamental thermodynamic models of Lysolipid properties.
A trial of satellite GPS telemetry on feral pigs in tropical mountain rainforest
Authors: Theuerkauf Jörn , Barrière Patrick , Cadin Ken , Gula Roman
Published: July 2022

We deployed two GPS collars and one innovative harness-mounted GPS backpack with Iridium or Globalstar satellite data transmission on feral pigs in mountain rainforest with deep valleys in New Caledonia during the hot wet season. Both collar and backpack with Iridium transmission achieved high success rates of locations and the rate increased with decreasing interval length between locations. The collar with Globalstar transmission had very low fix rates at 13-h intervals and was insufficient to produce robust results. The backpack harness was still functional after 20 months of use and proved to be a reliable alternative to collars.
Improving GWAS discovery and genomic prediction accuracy in biobank data
Authors: Orliac Etienne J. , Trejo Banos Daniel , Ojavee Sven E. , Läll Kristi , Mägi Reedik , Visscher Peter M. , Robinson Matthew R.
Published: July 2022

Genetically informed, deep-phenotyped biobanks are an important research resource and it is imperative that the most powerful, versatile, and efficient analysis approaches are used. Here, we apply our recently developed Bayesian grouped mixture of regressions model (GMRM) in the UK and Estonian Biobanks and obtain the highest genomic prediction accuracy reported to date across 21 heritable traits. When compared to other approaches, GMRM accuracy was greater than annotation prediction models run in the LDAK or LDPred-funct software by 15% (SE 7%) and 14% (SE 2%), respectively, and was 18% (SE 3%) greater than a baseline BayesR model without single-nucleotide polymorphism (SNP) markers grouped into minor allele frequency–linkage disequilibrium (MAF-LD) annotation categories. For height, the prediction accuracy
R
2
was 47% in a UK Biobank holdout sample, which was 76% of the estimated

h

SNP

2

. We then extend our GMRM prediction model to provide mixed-linear model association (MLMA) SNP marker estimates for genome-wide association (GWAS) discovery, which increased the independent loci detected to 16,162 in unrelated UK Biobank individuals, compared to 10,550 from BoltLMM and 10,095 from Regenie, a 62 and 65% increase, respectively. The average

χ

2

value of the leading markers increased by 15.24 (SE 0.41) for every 1% increase in prediction accuracy gained over a baseline BayesR model across the traits. Thus, we show that modeling genetic associations accounting for MAF and LD differences among SNP markers, and incorporating prior knowledge of genomic function, is important for both genomic prediction and discovery in large-scale individual-level studies.
Sensing the shape of a cell with reaction diffusion and energy minimization
Authors: Singh Amit R. , Leadbetter Travis , Camley Brian A.
Published: July 2022

Some dividing cells sense their shape by becoming polarized along their long axis. Cell polarity is controlled in part by polarity proteins, like Rho GTPases, cycling between active membrane-bound forms and inactive cytosolic forms, modeled as a “wave-pinning” reaction-diffusion process. Does shape sensing emerge from wave pinning? We show that wave pinning senses the cell’s long axis. Simulating wave pinning on a curved surface, we find that high-activity domains migrate to peaks and troughs of the surface. For smooth surfaces, a simple rule of minimizing the domain perimeter while keeping its area fixed predicts the final position of the domain and its shape. However, when we introduce roughness to our surfaces, shape sensing can be disrupted, and high-activity domains can become localized to locations other than the global peaks and valleys of the surface. On rough surfaces, the domains of the wave-pinning model are more robust in finding the peaks and troughs than the minimization rule, although both can become trapped in steady states away from the peaks and valleys. We can control the robustness of shape sensing by altering the Rho GTPase diffusivity and the domain size. We also find that the shape-sensing properties of cell polarity models can explain how domains localize to curved regions of deformed cells. Our results help to understand the factors that allow cells to sense their shape—and the limits that membrane roughness can place on this process.
Archaeal lipids trace ecology and evolution of marine ammonia-oxidizing archaea
Authors: Rattanasriampaipong Ronnakrit , Zhang Yi Ge , Pearson Ann , Hedlund Brian P. , Zhang Shuang
Published: July 2022

Archaeal membrane lipids are widely used for paleotemperature reconstructions, yet these molecular fossils also bear rich information about ecology and evolution of marine ammonia-oxidizing archaea (AOA). Here we identified thermal and nonthermal behaviors of archaeal glycerol dialkyl glycerol tetraethers (GDGTs) by comparing the GDGT-based temperature index (TEX86) to the ratio of GDGTs with two and three cyclopentane rings (GDGT-2/GDGT-3). Thermal-dependent biosynthesis should increase TEX86and decrease GDGT-2/GDGT-3 when the ambient temperature increases. This presumed temperature-dependent (PTD) trend is observed in GDGTs derived from cultures of thermophilic and mesophilic AOA. The distribution of GDGTs in suspended particulate matter (SPM) and sediments collected from above the pycnocline—shallow water samples—also follows the PTD trend. These similar GDGT distributions between AOA cultures and shallow water environmental samples reflect shallow ecotypes of marine AOA. While there are currently no cultures of deep AOA clades, GDGTs derived from deep water SPM and marine sediment samples exhibit nonthermal behavior deviating from the PTD trend. The presence of deep AOA increases the GDGT-2/GDGT-3 ratio and distorts the temperature-controlled correlation between GDGT-2/GDGT-3 and TEX86. We then used Gaussian mixture models to statistically characterize these diagnostic patterns of modern AOA ecology from paleo-GDGT records to infer the evolution of marine AOA from the Mid-Mesozoic to the present. Long-term GDGT-2/GDGT-3 trends suggest a suppression of today’s deep water marine AOA during the Mesozoic–early Cenozoic greenhouse climates. Our analysis provides invaluable insights into the evolutionary timeline and the expansion of AOA niches associated with major oceanographic and climate changes.
Structural basis for coupled ATP-driven electron transfer in the double-cubane cluster protein
Authors: Jeoung Jae-Hun , Nicklisch Sabine , Dobbek Holger
Published: July 2022

Electron transfers coupled to the hydrolysis of ATP allow various metalloenzymes to catalyze reductions at very negative reduction potentials. The double-cubane cluster protein (DCCP) catalyzes the reduction of small molecules, such as acetylene and hydrazine, with electrons provided by its cognate ATP-hydrolyzing reductase (DCCP-R). How ATP-driven electron transfer occurs is not known. To resolve the structural basis for ATP-driven electron transfer, we solved the structures of the DCCP:DCCP-R complex in three different states. The structures show that the DCCP-R homodimer is covalently bridged by a [4Fe4S] cluster that is aligned with the twofold axis of the DCCP homodimer, positioning the [4Fe4S] cluster to enable electron transfer to both double-cubane clusters in the DCCP dimer. DCCP and DCCP-R form stable complexes independent of oxidation state or nucleotides present, and electron transfer requires the hydrolysis of ATP. Electron transfer appears to be additionally driven by modulating the angle between the helices binding the [4Fe4S] cluster. We observed hydrogen bond networks running from the ATP binding site via the [4Fe4S] cluster in DCCP-R to the double-cubane cluster in DCCP, allowing the propagation of conformational changes. Remarkable similarities between the DCCP:DCCP-R complex and the nonhomologous nitrogenases suggest a convergent evolution of catalytic strategies to achieve ATP-driven electron transfers between iron–sulfur clusters.
Microstructures and properties of TIG welded 5A06-Al: responses to variable Ar-He alternating supplying conditions
Authors: Dai Hongbin , Miao Jian , Nie Hexu , Jiang Wei
Published: July 2022

During the TIG welding process, the interactions between arc plasma and molten pool could be periodically influenced by supplying Ar–He shield gas alternatively, which would affect the solidification and forming of the weld metal. In this work, the responses of microstructures and mechanical properties of the TIG welded 5A06 joint to the variable Ar–He alternating supplying conditions were investigated systematically. The variable shielding gas supply had a grain refining effect on the weld seam due to more violent and impacting effect on the molten pool. Moreover, the number of strengthening phases increased and became more dispersed, which increased the tensile strength further. The electrochemical experiment showed that the weld seam under continuous gas supply had better corrosion resistance.
Recent progress in the edge reconstruction of two-dimensional materials
Authors: Liu Yue , Shang Xiaoxue , Zhuang Jie , Li Da , Cui Tian
Published: July 2022

During the dimensionality reduction of a material from three-dimensional (3D) to two-dimensional (2D), the quasi-one-dimensional edge of a 2D material plays an equally important role as the 3D material surface and dominates most of its physical and chemical properties. Edge reconstruction is necessary due to the breaking of symmetry at the edge and the existence of unstable dangling bonds. Driven by the present demand for multifunctional nanodevices, this inherent edge engineering in 2D materials has attracted extensive research interest. Herein, we review the recent research progress of edge reconstruction of typical 2D materials, such as graphene, hexagonal boron nitride, 2D transition metal dichalcogenides, black phosphorene, and group-IV monochalcogenides, including the structures, stabilities, and formation mechanism of their edge reconstruction as well as the electronic, magnetic, and catalytic properties associated with the edge reconstruction. Finally, we evaluate the challenges and prospects for future research and development of the interesting edge reconstruction of 2D materials. We expect this review will help readers gain insight into the edge reconstruction of 2D materials from multiple perspectives.
Insulation degradation affected by micron metal particles attached on epoxy surface: charge accumulation and flashover voltage
Authors: Yang Zhuodong , Qi Bo , Yang Xiao , Gao Chunjia , Zhang Yi , Luo Yuan , Sun Caixin , Li Chengrong
Published: July 2022

The micron metal particles are inevitably produced in long-term operation condition of high voltage direct current SF6 insulated apparatus, which could frequently cause the surface discharge. Degradation of long-term surface discharge will be a severe threat to the insulation strength. Aiming at this problem, the surface charge accumulation and flashover voltage of epoxy itself before and after discharge degradation by particles were compared in this paper. The composition after degradation was measured by EDS and FTIR. The microstructure was observed by SEM. The roughness was measured as well. The trap distribution was measured by SPD. The mechanism of degradation and its effect on insulation characteristics were analyzed. The results show that the surface charge accumulation increase three times after degradation. Additionally, flashover voltage decreases 19% after degradation. The smoothly surface after degradation decrease the trap energy level for 14%, which might be the change reason of surface charge accumulation and flashover voltage. This paper can offer as a reference for the effect of micron metal particles on insulation degradation in SF6 gas insulated equipment.
Enhancement limit of sensitivity in laser absorption spectroscopy using a multipass cell composed of spherical concave mirrors
Authors: Matsui Makoto , Kobayashi Ryuji , Yasui Tomoya
Published: July 2022

The upper limit of sensitivity enhancement in a multipass process was investigated. In the calculation of 3.7 × 1013 ray-trace analysis, the sensitivity enhancement was increased to 13 510 for the mirror diameter of 75 mm with the mirror diameter. In the experiment, the sensitivity was enhanced by a factor of 1790 ± 160 for an effective mirror diameter of 50 mm, which was one-third of the numerical prediction. The lower enhancement could be attributed to the insufficient spatial and angular resolution of alignment optics. Therefore, this multipass cell has the potential to improve the sensitivity by three to four orders of magnitude.
Lightweight model-based two-step fine-tuning for fault diagnosis with limited data
Authors: Tang Tang , Wu Jie , Chen Ming
Published: July 2022

Deep learning-based fault diagnosis uses rich labeled data in achieving promising performance. However, in most real cases, only few labeled data can be acquired in fault diagnosis tasks, which is far from the essential requirement for training a deep model from scratch. To tackle this problem, a novel two-step fine-tuning process is primarily proposed, based on the idea of implementing information from a relevant auxiliary task via tuning less task-specific weights, which expands the fine-tuning method. A lightweight model is adapted for lower data consumption. Furthermore, a distance loss function is designed and embedded into the training process with a dynamic tuning process for sparser feature representations. Comprehensive experiments have been carried out. Results prove the effectiveness of the proposed method, which evidently improves the diagnosis performance and robustness in diagnosis tasks with limited data and has the potential for application to fault diagnosis of varying working conditions.
Low-temperature nanowelding silver nanowire hybrid flexible transparent conductive film for green light OLED devices
Authors: Wang Yuzhou , Liu Yan , Wang Tao , Liu Shuhui , Chen Zeng , Duan Shaobo
Published: July 2022

Flexible organic light emitting diodes (OLED) have attracted great attention in many applications. MXene based flexible transparent conductive films (TCFs) are the most promising next-generation electrodes for flexible electronics. Herein, the sandwich conductive structure of silver nanowires (AgNWs) network, new 2D nanosheets with excellent conductivity, hydrophilicity and mechanical flexibility and PEDOT:PSS contributes to a highly transparent and conductive hybrid electrode through a simple, scalable, low-cost spray method. The Ti3C2T
x
/AgNWs/PEDOT-PET film shows a low sheet resistance (<30 Ω/sq) and high transmittance (>80%) at 550 nm. Flexible OLED with such hybrid anode has the maximum brightness, current efficiency and current density, as high as 10 040 cd m−2, 3.7 cd A−1 and 535.5 mA cm−2, respectively. These results indicate that the novel Ti3C2T
x
/AgNWs/PEDOT-PET TCFs have a great potential for high-performance flexible optoelectronic devices.
A multimodal model fusing multiphase contrast-enhanced CT and clinical characteristics for predicting lymph node metastases of pancreatic cancer
Authors: Lu Qian , Zhou Chenjie , Zhang Haojie , Liang Lidu , Zhang Qifan , Chen Xuemin , Xu Xiaowu , Zhao Guodong , Ma Jianhua , Gao Yi , Peng Qing , Li Shulong
Published: July 2022

Objective. To develop a multimodal model that combines multiphase contrast-enhanced computed tomography (CECT) imaging and clinical characteristics, including experts’ experience, to preoperatively predict lymph node metastasis (LNM) in pancreatic cancer patients. Methods. We proposed a new classifier fusion strategy (CFS) based on a new evidential reasoning (ER) rule (CFS-nER) by combining nomogram weights into a previous ER rule-based CFS. Three kernelled support tensor machine-based classifiers with plain, arterial, and venous phases of CECT as the inputs, respectively, were constructed. They were then fused based on the CFS-nER to construct a fusion model of multiphase CECT. The clinical characteristics were analyzed by univariate and multivariable logistic regression to screen risk factors, which were used to construct correspondent risk factor-based classifiers. Finally, the fusion model of the three phases of CECT and each risk factor-based classifier were fused further to construct the multimodal model based on our CFS-nER, named MMM-nER. This study consisted of 186 patients diagnosed with pancreatic cancer from four clinical centers in China, 88 (47.31%) of whom had LNM. Results. The fusion model of the three phases of CECT performed better overall than single and two-phase fusion models; this implies that the three considered phases of CECT were supplementary and complemented one another. The MMM-nER further improved the predictive performance, which implies that our MMM-nER can complement the supplementary information between CECT and clinical characteristics. The MMM-nER had better predictive performance than based on previous classifier fusion strategies, which presents the advantage of our CFS-nER. Conclusion. We proposed a new CFS-nER, based on which the fusion model of the three phases of CECT and MMM-nER were constructed and performed better than all compared methods. MMM-nER achieved an encouraging performance, implying that it can assist clinicians in noninvasively and preoperatively evaluating the lymph node status of pancreatic cancer.
Customized whole brain-covering 3D GRASE in multi-delay pseudo-continuous arterial spin labeling for duplex distinct hemodynamic mapping contrasts of brain tissues and circulation pathways
Authors: Hu Yichen , Wei Qing , Zhou Zhongyang , Hu Junpu , Xie Jun , Xu Jian
Published: July 2022

Gradient and spin echo (GRASE) is widely employed in arterial spin labeling (ASL) as an efficient readout sequence. Hemodynamic parameter mappings of perfusion, such as cerebral blood flow (CBF) and arterial transit time (ATT), can be derived via multi-delay ASL acquisitions. Multi-delay ASL perfusion imaging inevitably suffers limited signal-to-noise ratio (SNR) since a motion-sensitized vessel suppressing module has to be employed to highlight perfusion signals. The present work reveals that in multi-delay ASL, manipulation of GRASE sequence on either planar imaging echo echo train for adjusted spatial resolutions or FSE echo train for modulated extent of T
2-blurring can significantly alter the mapping contrasts among tissues and among cerebral lobes under different pathways of blood circulation, and meanwhile regulates SNR. Four separate multi-delay ASL scans with different echo train designs in 3D whole brain covering GRASE were carried out for healthy subjects to evaluate the variations in regard to the parameter quantifications and SNR. Based on the quantification mappings, the GRASE acquisition with moderate spatial resolution (3.5 × 3.5 × 4 mm3) and segmented k
z scheme was recognized for the first time to be recommended for more unambiguous CBF and ATT contrasts between GM and WM in conjunction with more enhanced ATT contrast between anterior and posterior cerebral circulations, with reasonably good SNR. The technical proposal is of great value for the cutting-edge research of a variety of neurological diseases of global concerns.
Frequency-dependent depression of the NTS synapse affects the temporal response of the antihypertensive effect of auricular vagus nerve stimulation (aVNS)
Authors: Mun Junseung , Lee Jiho , Park Eunkyoung , Park Sung-Min
Published: July 2022

Objective. Auricular vagus nerve stimulation (aVNS) has recently emerged as a promising neuromodulation modality for blood pressure (BP) reduction due to its ease of use although its efficacy is still limited compared to direct baroreflex stimulation. Previous studies have also indicated that synaptic depression of nucleus tractus solitarius (NTS) in the baroreflex pathway depends on stimulus frequency. However, the nature of this frequency dependence phenomenon on antihypertensive effect has been unknown for aVNS. We aimed to investigate the antihypertensive effect of aVNS considering frequency-dependent depression characteristic in the NTS synapse. We explored NTS activation and BP reduction induced by aVNS and by direct secondary neuron stimulation (DS). Approach. Both protocols were performed with recording of NTS activation and BP response with stimulation for each frequency parameter (2, 4, 20, 50, and 80 Hz). Main results. The BP recovery time constant was significantly dependent on the frequency of DS and aVNS (DS—2 Hz: 8.17 ± 4.98; 4 Hz: 9.73 ± 6.3; 20 Hz: 6.61 ± 3.28; 50 Hz: 4.93 ± 1.65; 80 Hz: 4.00 ± 1.43, p < 0.001, Kruskal–Wallis (KW) H-test/aVNS—2 Hz: 4.02 ± 2.55; 4 Hz: 8.13 ± 4.05; 20 Hz: 6.40 ± 3.16; 50 Hz: 5.18 ± 2.37; 80 Hz: 3.13 ± 1.29, p < 0.05, KW H-test) despite no significant BP reduction at 2 Hz compared to sham groups (p > 0.05, Mann–Whitney U-test). Significance. Our observations suggest that the antihypertensive effect of aVNS is influenced by the characteristics of frequency-dependent synaptic depression in the NTS neuron in terms of the BP recovery time. These findings suggest that the antihypertensive effect of aVNS can be improved with further understanding of the neurological properties of the baroreflex associated with aVNS, which is critical to push this new modality for clinical interpretation.
so(2, 1) algebra, local Fermi velocity, and position-dependent mass Dirac equation
Authors: Bagchi Bijan , Ghosh Rahul , Quesne Christiane
Published: July 2022

We investigate the (1 + 1)-dimensional position-dependent mass Dirac equation within the confines of so(2, 1) potential algebra by utilizing the character of a spatial varying Fermi velocity. We examine the combined effects of the two when the Dirac equation is equipped with an external pseudoscalar potential. Solutions of the three cases induced by so(2, 1) are explored by profitably making use of a point canonical transformation.