bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dual trace inter-pulse interferometer for measurement of phase stability of ultra short laser pulse train
Authors: Sharma A. K. 
Published: February 2021

A dual trace intra-pulse and inter-pulse spatio-spectral interferometer has been set up to study the temporal stability of a ∼200 fs duration laser pulse train from a cw mode-locked laser oscillator. Simultaneous recording of twin interferograms helps identify the phase error in inter-pulse interferograms due to the diagnostic setup kept in a standard laboratory environment. Applicability of inter-pulse tilted pulse-front interferograms has been demonstrated to constitute an alternative inexpensive method for visual detection and estimation of phase slippage and pulse repetition frequency of an ultra short pulse train. The effect of pump beam intensity on the repetition rate of pulses due to accumulated intra-cavity non-linear phase shifts is also presented.
Intracellular pathways for lignin catabolism in white-rot fungi
Authors: del Cerro Carlos , Erickson Erika , Dong Tao , Wong Allison R. , Eder Elizabeth K. , Purvine Samuel O. , Mitchell Hugh D. , Weitz Karl K. , Markillie Lye Meng , Burnet Meagan C. , Hoyt David W. , Chu Rosalie K. , Cheng Jan-Fang , Ramirez Kelsey J. , Katahira Rui , Xiong Wei , Himmel Michael E. , Subramanian Venkataramanan , Linger Jeffrey G. , Salvachúa Davinia 
Published: February 2021

Significance
White-rot fungi play an essential role in global carbon cycling because of their extraordinary ability to extracellularly deconstruct lignin, a recalcitrant plant biopolymer. Despite this, the intracellular metabolism of lignin-deconstruction products by this fungal group has been largely overlooked, potentially due to a lack of genetic tools and challenging growth-tracking protocols, which complicate studies that are considered routine in other organisms. Here, we definitively demonstrate that white-rot fungi are also able to modify and utilize aromatic lignin-deconstruction products as a carbon source. Our study elucidates a critical process occurring in soil ecosystems, encouraging further study of lignin’s catabolic fate in diverse environmental conditions toward an improved understanding of the role of these fungi in facilitating carbon sequestration in nature.
Unique dynamics and exocytosis properties of GABAergic synaptic vesicles revealed by three-dimensional single vesicle tracking
Authors: Park Chungwon , Chen Xingxiang , Tian Chong-Li , Park Gyu Nam , Chenouard Nicolas , Lee Hunki , Yeo Xin Yi , Jung Sangyong , Tsien Richard W. , Bi Guo-Qiang , Park Hyokeun 
Published: February 2021

Significance
Despite playing an important role in maintaining brain function, the dynamics and exocytosis of inhibitory synaptic vesicles are poorly understood. Here, we tracked the three-dimensional position of single GABAergic vesicles up to the moment of exocytosis in real time by loading single GABAergic vesicles with quantum dots conjugated to antibodies against the luminal domain of the vesicular GABA transporter. We found that GABAergic synaptic vesicles have a smaller total travel length before fusion, a shorter fusion latency, and a higher prevalence of kiss-and-run fusion than synaptotagmin-1–labeled vesicles. Our findings provide evidence that inhibitory vesicles have a unique set of dynamics and exocytosis properties to support rapid inhibitory synaptic transmission.
The echo chamber effect on social media
Authors: Cinelli Matteo , De Francisci Morales Gianmarco , Galeazzi Alessandro , Quattrociocchi Walter , Starnini Michele 
Published: February 2021

Significance
We explore the key differences between the main social media platforms and how they are likely to influence information spreading and the formation of echo chambers. To assess the different dynamics, we perform a comparative analysis on more than 100 million pieces of content concerning controversial topics (e.g., gun control, vaccination, abortion) from Gab, Facebook, Reddit, and Twitter. The analysis focuses on two main dimensions: 1) homophily in the interaction networks and 2) bias in the information diffusion toward like-minded peers. Our results show that the aggregation in homophilic clusters of users dominates online dynamics. However, a direct comparison of news consumption on Facebook and Reddit shows higher segregation on Facebook.
ELF3 activated by a superenhancer and an autoregulatory feedback loop is required for high-level HLA-C expression on extravillous trophoblasts
Authors: Li Qin , Meissner Torsten B. , Wang Fang , Du Ziming , Ma Sai , Kshirsagar Sarika , Tilburgs Tamara , Buenrostro Jason D. , Uesugi Motonari , Strominger Jack L. 
Published: February 2021

SignificanceSeveral techniques have identified ELF3 as particularly important in regulating trophoblast-specific HLA-C expression. This results from a single-nucleotide difference in the promotor of the HLA-C gene at the RFX5 binding site that creates an ELF3 binding site not found in the HLA-A or HLA-B promoters. We discovered a superenhancer and a positive autoregulatory feedback loop that promotes expression of the ELF3 gene in trophoblasts. Disruption of either the superenhancer by (+)-JQ1 or interference with the positive-feedback loop by wrenchnolol decreased ELF3 levels, and thus HLA-C expression. Aberrations of this complex regulatory system could be involved in control of infection, miscarriage, preterm birth, preeclampsia, as well as parturition in normal pregnancy and in development of choriocarcinoma.
Fluoropolymer coatings deposited on rotating cylindrical surfaces by HW CVD: experiment and simulation
Authors: Bykov Nikolay Y , Ronshin Fedor V , Safonov Alexey I , Starinskiy Sergey V , Sulyaeva Veronica S 
Published: February 2021

Abstract
The hot wire chemical vapor deposition method has been adapted to deposit fluoropolymer coatings on small-radius rotating surfaces. The influence of the rotational frequency of a cylindrical sample during the deposition process on the formation of a layer of fluoropolymer coating was studied. It was found that the rotational frequency of the cylindrical sample significantly changed the morphology of the resulting coating. It was shown that with an increase in the sample’s rotational frequency from 1 to 100 rpm, the deposition rate decreased and the coating structure degraded. To establish the reasons for this effect, a numerical study of the flow around a rotating cylindrical sample was carried out for a range of low gas velocities and densities in the reactor. The simulations are based on solving the Navier–Stokes equation with no slip and velocity slip boundary conditions for a rotating surface. It was found that the main reason for the decrease in the deposition rate was associated with the effect of the formation of a closed circulation flow region above the sample’s surface during rotation. The dependence of the characteristic size of this region on the rotational frequency of the cylinder sample was close to linear. The effects of surface boundary conditions were also analyzed.
Recent progress in deep-depletion diamond metal–oxide–semiconductor field-effect transistors
Authors: Masante Cédric , Rouger Nicolas , Pernot Julien 
Published: February 2021

Abstract
Diamond has been explored to develop prototype field-effect transistors (FETs). At present, various architectures that are suited to high temperature and high-radiation environments are still under investigation for power electronics applications. Recently, the deep-depletion diamond metal–oxide–semiconductor FET (D3MOSFET) concept has been introduced and demonstrated to be a good candidate for designing efficient diamond MOSFETs. In this paper, a general introduction to the concept of deep depletion is given. The key issues concerning the design and fabrication of this kind of diamond MOSFET are then described and discussed in terms of quasi static performance (the ‘on’ and ‘off’ states). A demonstration of the working regimes of a fabricated normally-on D3MOSFET is described, which reached a critical field of at least 5.4 MV cm−1 at a drain–source bias of −175 V, without electric field relaxation structures. The minimum on-state resistance was measured and found to be R

ON,S
= 50 mΩ cm2 at 250 ∘C. Finally, the D3MOSFET is contextualized as part of a global research effort to develop diamond power FETs. Some of the main challenges regarding the fabrication of competitive D3MOSFETs and, more generally, diamond power devices are discussed.
Perfect absorber with separated ‘dielectric–metal–ground’ metamaterial structure
Authors: Wang Han , Yan Bo , Jin Huizhen , Wang Zhigang , Guo Lanjun , Li Boyan , Yu Bo , Gong Cheng 
Published: February 2021

Abstract
A metamaterial perfect absorber whose effective thickness is less than 1/1000 of the operating wavelength is proposed. Different from the traditional ‘metal–dielectric–ground’ type metamaterial absorber, it adopts a novel ‘dielectric–metal–ground’ structure, and the ‘dielectric–metal’ structure is separated from the ‘ground’. Through this design, the effective thickness of the absorber is reduced to about 1/2200 of the wavelength. This will make the absorber suitable for imaging and sensing applications. Next, a bi-material cantilever absorber based on the proposed structure is designed and fabricated to demonstrate the high absorption properties in the case of ultra-thin thickness. In addition, a reflective spectroscopy system based on a vector network analyzer is built to test the absorption performance. The measured results, showing that it has an absorptivity of close to 97% at 94 GHz, are in good agreement with simulations.
Absence of local moments in the kagome metal KV3Sb5 as determined by muon spin spectroscopy
Authors: Kenney Eric M , Ortiz Brenden R , Wang Chennan , Wilson Stephen D , Graf Michael J 
Published: February 2021

Abstract
We have carried out muon spin relaxation and rotation measurements on the newly discovered kagome metal KV3Sb5, and find a local field dominated by weak magnetic disorder which we associate with the nuclear moments present, and a modest temperature dependence which tracks the bulk magnetic susceptibility. We find no evidence for the existence of V4+ local moments, suggesting that the physics underlying the recently reported giant unconventional anomalous Hall effect in this material warrants further studies.
Nanometre imaging of Fe3GeTe2 ferromagnetic domain walls
Authors: Hopkinson David G , Seki Takehito , Clark Nicholas , Chen Runze , Zou Yichao , Kimura Ayumi , Gorbachev Roman V , Thomson Thomas , Shibata Naoya , Haigh Sarah J 
Published: February 2021

Abstract
Fe3GeTe2 is a layered crystal which has recently been shown to maintain its itinerant ferromagnetic properties even when atomically thin. Here, differential phase contrast scanning transmission electron microscopy is used to investigate the domain structure in a Fe3GeTe2 cross-sectional lamella at temperatures ranging from 95 to 250 K and at nanometre spatial resolution. Below the experimentally determined Curie temperature (T
C) of 191 K, stripe domains magnetised along 〈0001〉, bounded with 180◦ Bloch type domain walls, are observed, transitioning to mixed Bloch−Néel type where the cross-sectional thickness is reduced below 50 nm. When warming towards T
C, these domains undergo slight restructuring towards uniform size, before abruptly fading at T
C. Localised loss of ferromagnetic order is seen over time, hypothesised to be a frustration of ferromagnetic order from ambient oxidation and basal cracking, which could enable selective modification of the magnetic properties for device applications.
Synthesis of coralloid carbon nitride polymers and photocatalytic selective oxidation of benzyl alcohol
Authors: Gu Qian , Jiang Pingping , Shen Yirui , Leng Yan , Wai Phyu Thin , Zhang Kai , Haryono Agus 
Published: February 2021

Abstract
Polymeric carbon nitride (C3N4) is currently the most potential nonmetallic photocatalyst, but it suffers from low catalytic activity due to rapid electron–hole recombination behavior and low specific surface area. The morphology control of C3N4 is one of the effective methods used to achieve higher photocatalytic performance. Here, bulk, lamellar and coralloid C3N4 were synthesized using different chemical methods. The as-prepared coralloid C3N4 has a higher specific surface area (123.7 m2 · g−1) than bulk (5.4 m2 · g−1) and lamellar C3N4 (2.8 m2 · g−1), thus exhibiting a 3.15- and 2.59-fold higher photocatalytic efficiency for the selective oxidation of benzyl alcohol than bulk and lamellar C3N4, respectively. Optical characterizations of the photocatalysts suggest that coralloid C3N4 can effectively capture electrons and accelerate carrier separation, which is caused by the presence of more nitrogen vacancies. Furthermore, it is demonstrated that superoxide radicals (·O2
−) and holes (h+) play major roles in the photocatalytic selective oxidation of benzyl alcohol using C3N4 as a photocatalyst.
Rotational dynamics of proteins in nanochannels: role of solvent’s local viscosity
Authors: Haridasan Navaneeth , Sathian Sarith P 
Published: February 2021

Abstract
Viscosity variation of solvent in local regions near a solid surface, be it a biological surface of a protein or an engineered surface of a nanoconfinement, is a direct consequence of intermolecular interactions between the solid body and the solvent. The current coarse-grained molecular dynamics study takes advantage of this phenomenon to investigate the anomaly in a solvated protein’s rotational dynamics confined using a representative solid matrix. The concept of persistence time, the characteristic time of structural reordering in liquids, is used to compute the solvent’s local viscosity. With an increase in the degree of confinement, the confining matrix significantly influences the solvent molecule’s local viscosity present in the protein hydration layer through intermolecular interactions. This effect contributes to the enhanced drag force on protein motion, causing a reduction in the rotational diffusion coefficient. Simulation results suggest that the direct matrix-protein non-bonded interaction is responsible for the occasional jump and discontinuity in orientational motion when the protein is in very tight confinement.
Efficient radiation dose reduction in whole-brain CT perfusion imaging using a 3D GAN: performance and clinical feasibility
Authors: Dashtbani Moghari Mahdieh , Zhou Luping , Yu Biting , Young Noel , Moore Krystal , Evans Andrew , Fulton Roger R , Kyme Andre Z 
Published: February 2021

Abstract
Dose reduction in cerebral CT perfusion (CTP) imaging is desirable but is accompanied by an increase in noise that can compromise the image quality and the accuracy of image-based haemodynamic modelling used for clinical decision support in acute ischaemic stroke. The few reported methods aimed at denoising low-dose CTP images lack practicality by considering only small sections of the brain or being computationally expensive. Moreover, the prediction of infarct and penumbra size and location—the chief means of decision support for treatment options—from denoised data has not been explored using these approaches. In this work, we present the first application of a 3D generative adversarial network (3D GAN) for predicting normal-dose CTP data from low-dose CTP data. Feasibility of the approach was tested using real data from 30 acute ischaemic stroke patients in conjunction with low dose simulation. The 3D GAN model was applied to 643 voxel patches extracted from two different configurations of the CTP data—frame-based and stacked. The method led to whole-brain denoised data being generated for haemodynamic modelling within 90 s. Accuracy of the method was evaluated using standard image quality metrics and the extent to which the clinical content and lesion characteristics of the denoised CTP data were preserved. Results showed an average improvement of 5.15–5.32 dB PSNR and 0.025–0.033 structural similarity index (SSIM) for CTP images and 2.66–3.95 dB PSNR and 0.036–0.067 SSIM for functional maps at 50% and 25% of normal dose using GAN model in conjunction with a stacked data regime for image synthesis. Consequently, the average lesion volumetric error reduced significantly (p-value <0.05) by 18%–29% and dice coefficient improved significantly by 15%–22%. We conclude that GAN-based denoising is a promising practical approach for reducing radiation dose in CTP studies and improving lesion characterisation.
High intrinsic lattice thermal conductivity in monolayer MoSi2N4
Authors: Yu Jihai , Zhou Jian , Wan Xiangang , Li Qingfang 
Published: February 2021

Abstract
Very recently, a novel two-dimension (2D) MXene, MoSi2N4, was successfully synthesized with excellent ambient stability, high carrier mobility, and moderate band gap (2020 Science
369 670). In this work, the intrinsic lattice thermal conductivity of monolayer MoSi2N4 is predicted by solving the phonon Boltzmann transport equation based on the first-principles calculations. Despite the heavy atomic mass of Mo and complex crystal structure, the monolayer MoSi2N4 unexpectedly exhibits a quite high lattice thermal conductivity over a wide temperature range between 300 to 800 K. At 300 K, its in-plane lattice thermal conductivity is 224 Wm−1 K−1. The detailed analysis indicates that the large group velocities and small anharmonicity are the main reasons for its high lattice thermal conductivity. We also calculate the lattice thermal conductivity of monolayer WSi2N4, which is only a little smaller than that of MoSi2N4. Our findings suggest that monolayer MoSi2N4 and WSi2N4 are potential 2D materials for thermal transport in future nano-electronic devices.
Non uniqueness of non runaway solutions of Abraham—Lorentz—Dirac equation in an external laser pulse
Authors: Carati A , Stroppi M 
Published: February 2021

Abstract
In the paper (Carati et al 1995 Non Linearity
8 65-79) it was shown that, for motions on a line under the action of a potential barrier, the third-order Abraham–Lorentz–Dirac equation presents the phenomenon of non uniqueness of non runaway solutions. Namely, at least for a sufficiently steep barrier, the physical solutions of the equation are not determined by the ‘mechanical state’ of position and velocity, and knowledge of the initial acceleration too is required. Due to recent experiments, both in course and planned, on the interactions between strong laser pulses and ultra relativistic electrons, it becomes interesting to establish whether such a non uniqueness phenomenon extends to the latter case, and for which ranges of the parameters. In the present work we will consider just the simplest model, i.e., the case of an electromagnetic plane wave, and moreover the Abraham–Lorentz–Dirac equation will be dealt with in the non relativistic approximation. The result we found is that the non uniqueness phenomenon occurs if, at a given frequency of the incoming wave, the field intensity is sufficiently large. An analytic estimate of such a threshold is also given. At the moment it is unclear whether such a phenomenon applies also in the full relativistic case, which is the one of physical interest.
Inhibition of Na+/H+ exchanger modulates microglial activation and scar formation following microelectrode implantation
Authors: Dubaniewicz Mitchell , Eles James R , Lam Stephanie , Song Shanshan , Cambi Franca , Sun Dandan , Wellman Steven M , Kozai Takashi D Y 
Published: February 2021

Abstract

Objective. Intracortical microelectrodes are an important tool for neuroscience research and have great potential for clinical use. However, the use of microelectrode arrays to treat neurological disorders and control prosthetics is limited by biological challenges such as glial scarring, which can impair chronic recording performance. Microglia activation is an early and prominent contributor to glial scarring. After insertion of an intracortical microelectrode, nearby microglia transition into a state of activation, migrate, and encapsulate the device. Na+/H+ exchanger isoform-1 (NHE-1) is involved in various microglial functions, including their polarity and motility, and has been implicated in pro-inflammatory responses to tissue injury. HOE-642 (cariporide) is an inhibitor of NHE-1 and has been shown to depress microglial activation and inflammatory response in brain injury models. Approach. In this study, the effects of HOE-642 treatment on microglial interactions to intracortical microelectrodes was evaluated using two-photon microscopy in vivo. Main results. The rate at which microglia processes and soma migrate in response to electrode implantation was unaffected by HOE-642 administration. However, HOE-642 administration effectively reduced the radius of microglia activation at 72 h post-implantation from 222.2 µm to 177.9 µm. Furthermore, treatment with HOE-642 significantly reduced microglial encapsulation of implanted devices at 5 h post-insertion from 50.7 ± 6.0% to 8.9 ± 6.1%, which suggests an NHE-1-specific mechanism mediating microglia reactivity and gliosis during implantation injury. Significance. This study implicates NHE-1 as a potential target of interest in microglial reactivity and HOE-642 as a potential treatment to attenuate the glial response and scar formation around implanted intracortical microelectrodes.
Potential-based three-dimensional route choice model for pedestrian evacuation on terraced stands
Authors: Liu Ying , Du Jiawang , Sun Cheng 
Published: February 2021

Abstract
This study proposes a potential-based three-dimensional cellular automata model to describe the route choice behavior of pedestrians while evacuating terraced stands. The model takes into account the pedestrians’ states of sitting, standing, and moving, and the possible transitions on terraced stands. The proposed potential field algorithm reflects the influence on route choice behavior of heterogeneous heights, route distance, pedestrian congestion, and route capacity. Three parameters related to the pedestrians’ behaviors in the spaces with heterogeneous heights are then analyzed to demonstrate the ability of the model to reproduce pedestrian route choice behaviors on terraced stands. Finally, empirical data observed in a terraced stand of a stadium are applied for further validation. The results show that the proposed model performs consistently well with the observed data.
Digital sorting of laser beams by radial number: degenerate and non-degenerate states
Authors: Volyar A V , Bretsko M V , Akimova Ya E , Egorov Yu A 
Published: February 2021

Abstract
We have created and tested a computer sorting method of Laguerre-Gauss (LG) radial modes with permanent topological charge arising from the perturbation of both single LG beams and their composition using a diaphragm with different radius R. The method based on computer analysis of the intensity moments. We considered two types of perturbed beams: single LG beam and complex LG beams with different radial number included in an integral array. The diaphragm acts on LG beam in such a way that when the radius of the diaphragm decreases, a set of secondary LG modes with different radial indices, which are characterized by different mode spectra, arise. Reconstructed spectrum using digital processing allows one to reconstruct the real LG modes and calculate the measure of uncertainty arising under the action of a disturbance, using the concept of information entropy. The calculations performed showed that the correlation degree of the measured disturbed beams is about 0.94. It was also found that the perturbation of a complex beam leads to the appearance of a degenerate spectrum in amplitudes, since one spectral line corresponds to a whole set of modes with different radial indices. To detect the spectrum, it was required to know M keys, which are the spectra of the amplitudes of nondegenerate perturbed beams in our experiment, degree of correlation was also 0.94.