bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns of adolescent eating behavior during the COVID-19 pandemic
Authors: Zhuravleva Ludmila , Zarubina Elena , Ruchkin Aleksey , Simachkova Natalya , Chupina Irina
Published: November 2022

The ongoing COVID-19 pandemic has exacerbated problems of ensuring food security for all strata of the population of many countries of the world, including Russia. For scientific research of these problems, development and implementation of effective practical recommendations in the international scientific community has developed an interdisciplinary the concept of “food security”. Food security is a stable condition processes, mechanisms, infrastructures, relationships and influences related to food production, storage, transportation, supply, consumption and disposal food waste. The concept of food security it is the key to studying the problems of providing for the population food economists, lawyers, specialists management and logistics, marketers, social psychologists, nutritionists, as well as specialists in the field of other sciences. Its place in comprehensive security research food security is also found by the sociology of nutrition, which studies food systems, first of all, in its links such as the consumption of food by various social groups and food waste management. During the third stage of the sociological research, the topic which was the change in the eating behavior of various socio-demographic groups of Russian society in the conditions of ongoing pandemics, the author’s team conducted an analysis of food practices children and adolescents in the conditions of the COVID-19 pandemic. Methods of conducting smart survey and in-depth interviews were selected for the research. Analysis the results of the study allowed us to formulate recommendations, which can be used in educational and educational institutions, as well as in families for the formation of a food culture children and adolescents, improving food security of the specified socio-demographic group.
Die Pflegekammer Nordrhein-Westfalen kommt
Authors: Wiegard-Szramek Ina
Published: November 2022

Der Fachverband nephrologischer Berufsgruppen e. V. (fnb) unterstützt das Ziel der Einrichtung von Pflegekammern, um unsere Profession zu stärken. Wir erhoffen uns von der Mitsprache, unsere Arbeitsbedingen zu verbessern, die Ausbildungsinhalte mitzugestalten, an wesentlichen Gesetzen mitzuarbeiten und damit letztendlich eine Selbstverwaltung unserer Profession zu installieren. Nur durch den Zusammenschluss vieler Stimmen kann man etwas verändern; Ina Wiegard-Szramek, Essen.
Vocal Folds Leukoplakia: The Efficacy of Vitamin A in the Initial Treatment
Authors: Botini Dayane Silvestre , Rodrigues Sergio Augusto , Castilho Gustavo Leão , Mercuri Gustavo , Martins Regina Helena Garcia
Published: November 2022

Introduction Laryngeal leukoplakia corresponds to a white lesion in the mucosa developed by the deposit of keratin in the epithelium, potentiated by chronic smoking. It is considered a preneoplastic lesion. Surgery is the most adopted treatment; however, non-surgical treatment is advocated by some authors.

Objective To evaluate the effectiveness of vitamin A in the management of vocal fold leukoplakia.

Methods Patients with videolaryngoscopy diagnosis of vocal fold leukoplakia were selected. The endoscopic images were photographed and with the aid of the ImageJ software (National Institutes of Health, Bethesda, MD, USA), the proportion of the size of the leukoplakia was calculated. Eligible patients were prescribed 50,000U of vitamin A, twice daily for 2 months, at which point videolaryngostroboscopy was repeated for comparative analysis between pre and posttreatment. The efficacy of the treatment was classified as: outcome I – complete improvement of the lesion, outcome II – partial improvement, and outcome III – no difference or increased lesion size.

Results Fifteen patients (eight women, seven men) were included, six of whom had bilateral lesions. Smoking was reported in 86.8% of patients. Complete improvement of the lesion was found in 7 cases (33.4%, outcome I), partial improvement in 6 (28.6%, outcome II), and worsening of the injury in 8 (38.1%, outcome III). Of the latter, 6 underwent microsurgery; histopathology indicated absence of dysplasia in 3, and mild dysplasia in 3.

Conclusions In this study, the treatment with vitamin A at a dose of 100,000 IU daily for 2 months was effective in reducing the laryngeal leukoplakia size in 62% of cases.
Electric arc I–V modeling and related plasma spectrometry issues
Authors: Zhovtyansky V. , Kolesnikova E. , Lelyukh Yu. , Tkachenko Ya.
Published: November 2022

This article is devoted to studying the properties of an electric arc column as a development of the authors’ early pioneer experiments. The object of modeling is a free-burning electric arc between evaporating copper electrodes in atmospheric air as the basis for the functioning of many modern technologies. It includes the determination of fundamental characteristics, such as the radial structure, and the current–voltage characteristics of the electric arc column under the assumption of plasma equilibrium. The middle cross section between the electrodes of a spheroidal shape arc is considered in order to limit the problem to a one-dimensional cylindrical approximation. It is strictly solved from the Elenbaas–Heller energy equation, with no resorting to the simplified channel model. The radial structure of the electric arc column is carefully considered with known temperature functions of electric and heat conductivities. Convenient functional approximations depending on temperature are proposed for the mentioned coefficients of copper–air plasma. The boundary between the arc column and atmospheric air is strictly located taking into account the chemical processes in the plasma of the copper–air mixture. The paper also presents some bases features of high-speed plasma spectrometry, substantiating the reliability of the obtained experimental data. As shown, the non-monotonicity of the current–voltage characteristics can arise due to the non-monotonicity of thermal conductivity as a function of temperature. Also, the loss of energy with the so-called ionization energy diffusion is insignificant in the overall energy balance of the arc. The results of the numerical simulation are compared with the experimental data.
Segmentation of human aorta using 3D nnU-net-oriented deep learning
Authors: Li Feng , Sun Lianzhong , Lam Kwok-Yan , Zhang Songbo , Sun Zhongming , Peng Bao , Xu Hongzeng , Zhang Libo
Published: November 2022

Computed tomography angiography (CTA) has become the main imaging technique for cardiovascular diseases. Before performing the transcatheter aortic valve intervention operation, segmenting images of the aortic sinus and nearby cardiovascular tissue from enhanced images of the human heart is essential for auxiliary diagnosis and guiding doctors to make treatment plans. This paper proposes a nnU-Net (no-new-Net) framework based on deep learning (DL) methods to segment the aorta and the heart tissue near the aortic valve in cardiac CTA images, and verifies its accuracy and effectiveness. A total of 130 sets of cardiac CTA image data (88 training sets, 22 validation sets, and 20 test sets) of different subjects have been used for the study. The advantage of the nnU-Net model is that it can automatically perform preprocessing and data augmentation according to the input image data, can dynamically adjust the network structure and parameter configuration, and has a high model generalization ability. Experimental results show that the DL method based on nnU-Net can accurately and effectively complete the segmentation task of cardiac aorta and cardiac tissue near the root on the cardiac CTA dataset, and achieves an average Dice similarity coefficient of 0.9698 ± 0.0081. The actual inference segmentation effect basically meets the preoperative needs of the clinic. Using the DL method based on the nnU-Net model solves the problems of low accuracy in threshold segmentation, bad segmentation of organs with fuzzy edges, and poor adaptability to different patients’ cardiac CTA images. nnU-Net will become an excellent DL technology in cardiac CTA image segmentation tasks.
Sustainable carbon sources for green laser-induced graphene: A perspective on fundamental principles, applications, and challenges
Authors: C. Claro Pedro I. , Pinheiro Tomás , Silvestre Sara L. , Marques Ana C. , Coelho João , Marconcini José M. , Fortunato Elvira , C. Mattoso Luiz H. , Martins Rodrigo
Published: November 2022

Since the discovery of laser-induced graphene (LIG), significant advances have been made to obtain green LIG (gLIG) from abundant, eco-friendly, natural, and organic renewable bio-based carbon sources. Recently, some sustainable and cost-effective electronic devices have been designed with gLIG, resulting in diverse solutions to the environmental impact caused by electronic waste (e-waste). However, there are still several challenges that must be addressed regarding the widespread market implementation of gLIG-based products, from synthesis to practical applications. In this review, we focus on sustainable precursor sources, their conversion mechanisms, physical and chemical properties and applications, along with the challenges related to its implementation, showing the future opportunities and perspectives related to this promising new material. Various systems based on gLIG for energy storage, electrocatalysis, water treatment, and sensors have been reported in the literature. Additionally, gLIG has been proposed for ink formulation or incorporation into polymer matrices, to further expand its use to non-carbon-based substrates or applications for which pristine LIG cannot be directly used. In this way, it is possible to apply gLIG on diverse substrates, aiming at emerging wearable and edible electronics. Thus, this review will bring an overview of gLIG developments, in accordance with the European Green Deal, the United Nations Sustainable Development Goals and the new era of internet-of-things, which demands cost-effective electronic components based on the principles of energy efficiency and sustainable production methods.
Investigating the effect of density variation on pitch angle scattering events of runaway electrons as observed through electron cyclotron emission diagnostic at Aditya-upgrade tokamak
Authors: Siju Varsha , Pandya Santosh P. , Pathak S. K. , Nagora Umesh , Purohit Shishir , Patel Ansh , Gupta M. K. , Tahiliani K. , Tanna R. L. , Jadeja Kumarpalsinh , Kumar Rohit , Ghosh J.
Published: November 2022

Nascent observations about the influence of kinetic instabilities on electron cyclotron emission (ECE) from runaway electrons (REs) have been detected and explored at the Aditya-Upgrade (Aditya-U) tokamak. The developed broadband ECE radiometer system offers wideband measurements by integrating several radio frequency units with a fixed intermediate frequency receiver with multiple channels, which is a novel approach to meet the needs of the localized measurements at various toroidal fields and extend the system dynamic range. The low density (ne ≤ 1 × 10−19 m−3) plasma discharges at Aditya-U are consistently accompanied by a 20%–40% increase in the ECE radiometer signal amplitude within 100 µs and sporadic step-like modulations. The Pitch Angle Scattering (PAS) of REs induced by kinetic instabilities is a potential candidate for their occurrence. This steep jump in the radiometer signals was detected due to its high temporal resolution of 10 µs. A “PREDICT” code that employs the relativistic test particle model validates these experimental findings of the radiometer diagnostic for the first time for Aditya-U tokamak. Preliminary observations of the ECE radiometer signals also show that additional gas puffs can be used to vary the trigger timings of such PAS events or even lead to their complete avoidance.
A high-throughput catalyst synthesis system for Ag-based catalysts
Authors: Deng Zhuoran , Zhao Liqiang , Cheng Daojian
Published: November 2022

Ag-based catalysts have been used in many practical reactions, such as p-nitrophenol reduction, due to the advantages of low cost and excellent activity. In order to facilitate the development of Ag-based catalysts, it may be helpful to use automated equipment for experiments. In this study, a system for the high-throughput synthesis of Ag-based catalysts was developed based on a facile impregnation method. Notably, the system automates the batch synthesis of Ag-based catalysts by setting the catalyst formulation in a dedicated software. Moreover, the software used employs the ant colony algorithm to optimize the synthesis path and improve the synthesis efficiency. The catalysts obtained from the high-throughput system are found to be similar to the manually prepared samples based on comparison of characterization results. In addition, experiments also reveal that this high-throughput system is capable of achieving high-throughput synthesis of Ag-based catalysts at the gram level. The synthesis of Pt–Ag bimetallic catalysts shows that this high-throughput system can be effectively used for exploratory experiments. This work paves the way for a high-throughput technique to synthesize Ag-based catalysts in a short period of time, which could be extended to the preparation of other catalyst systems. Moreover, the high-throughput synthesis system of Ag-based catalysts provides a feasible prerequisite for subsequent high-throughput characterization, which is a significant advancement in the development of industrial catalysts.
Whose line is it anyway? A self-training spectral line identification code for plasma physics experiments
Authors: Tobin M. , Nations M. ,   the TAE Team
Published: November 2022

The process of associating spectral peaks in emission radiation data with particular charge states of specific elements is a common task in the field of plasma diagnostics in both laboratory and astrophysical settings. Existing techniques for this purpose are often highly manual or can rely heavily on theoretical models and assumptions of plasma parameters. We present a numerical approach to largely automate this process. The approach combines statistics from experimental data with theoretical predictions of transition strengths and observed emission intensity data in order to accomplish the task of spectral line identification in a rigorous, quantitative way, reporting confidence levels in its own predictions for each wavelength. Weighted by this confidence, the method identifies sources of 31 test emission lines in the C-2W device with 99.99% accuracy (compared to manual identification). Similar performance is demonstrated on synthetic datasets and spectroscopic observations of the planetary nebula NGC 6543, with accuracies of between 95% and 100%. The approach is scalable, portable to a wide variety of spectroscopic datasets and significantly faster and more rigorous than manual methods.
Numerical investigation of the segregation of turbulent emulsions
Authors: Trummler T. , Begemann A. , Trautner E. , Klein M.
Published: November 2022

We study the segregation of emulsions in decaying turbulence using direct numerical simulations in combination with the volume of fluid method. To this end, we generate emulsions in forced homogeneous isotropic turbulence and then turn the forcing off and activate the gravitational acceleration. This allows us to study the segregation process in decaying turbulence and under gravity. We consider non-iso-density emulsions, where the dispersed phase is the lighter one. The segregation process is driven by both the minimization of the potential energy achieved by the sinking of the heavier phase as well as the minimization of the surface energy achieved by coalescence. To study these two processes and their impacts on the segregation progress in detail, we consider different buoyancy forces and surface tension coefficients in our investigation, resulting in five different configurations. The surface tension coefficient also alters the droplet size distribution of the emulsion. Using the three-dimensional simulation results and the monitored data, we analyze the driving mechanisms and their impact on the segregation progress in detail. We propose a dimensionless number that reflects the energy release dominating the segregation. Moreover, we evaluate the time required for the rise of the lighter phase and study correlations with the varied parameters: gravitational acceleration and surface tension coefficient.
Coulomb expansion of a thin dust cloud observed experimentally under afterglow plasma conditions
Authors: Chaubey Neeraj , Goree J.
Published: November 2022

The Coulomb expansion of a thin cloud of charged dust particles was observed experimentally, in a plasma afterglow. This expansion occurs due to mutual repulsion among positively charged dust particles, after electrons and ions have escaped the chamber volume. In the experiment, a two-dimensional cloud of dust particles was initially levitated in a glow-discharge plasma. The power was then switched off to produce afterglow conditions. The subsequent fall of the dust cloud was slowed by reversing the electric force, to an upward direction, allowing an extended observation. At early time, measurements of the Coulomb expansion in the horizontal direction are found to be accurately modeled by the equation of state for a uniformly charged thin disk. Finally, bouncing from the lower electrode was found to be avoided by lowering the impact velocity <100 mm/s.
Green synthesis of silver nanoparticles (AgNPs) incorporated with Adenia trilobata leaf extracts and its anti-bacterial application
Authors: Islam Md. Johurul , Kamaruzzaman  , Hossain Md. Forhad , Awal Md. Abdul , Rahman Md. Rezwanur , Alam M. M.
Published: November 2022

Currently, eco-friendly, cost-effective, and simple synthesis techniques are drawing the attention of nanoparticle researchers. The conversion of silver ions to silver nanoparticles (AgNPs) is carried out using the Adenia trilobata leaf extract, which is capable of acting as an exclusive reducing agent. AgNPs show very crucial antibacterial properties and are nontoxic for humans. The color of the solution changes from light blue to brown, ensuring the formation on nanoparticles. The biosynthesized AgNPs are incorporated into cotton fiber, and their antibacterial activity on gram negative (E. coli) bacteria has been studied. The UV/Vis and absorption spectroscopy analysis shows a surface plasmon resonance peak at 445 nm. The x-ray diffraction measurement reveals peaks at 38.02 and 44.23, and the average particle size is 18.30 nm. Field emission scanning electron microscopy has been performed to find the size, shape, and morphology of the treated nanoparticles and the AgNP-incorporated cotton fiber. The Fourier transform infrared spectroscopy result shows the presence of functional groups of AgNPs and capping agents. The antibacterial activity on gram negative (E. coli) bacterial strains for the both cases showed a promising result.
A hybrid memristor with oxide-polymer heterojunction
Authors: Zhang Zhong-Da , Zhong Ya-Nan , Shen Cong , Huang Hai-Tian , Lu Zhen-Ni , Xu Jian-Long , Gao Xu , Wang Sui-Dong
Published: November 2022

A hybrid memristor based on the bilayer structure of indium gallium zinc oxide (IGZO)/polyvinyl alcohol (PVA) is developed, which demonstrates device state updates in an analog manner with high reliability. The IGZO/PVA heterojunction is crucial for the realization of the memristive characteristics, presumably associated with oxygen ion redistribution across the IGZO/PVA interface. The hybrid memristor may act as an electronic synapse, being capable of emulating synaptic potentiation with good linearity, synaptic depression, and paired-pulse facilitation. It highlights potential applications of the oxide-polymer heterojunction in the exploration of neuromorphic devices.
Numerical simulations of a toroidal droplet breakup in viscous oils
Authors: Qin Shiyi , Li Zhaolin , Wang Xun , Li Kai , Chen Xue
Published: November 2022

Toroidal droplets are inherently unstable in viscous oils; they either shrink to a single drop or break into several spherical droplets due to Rayleigh–Plateau instability. In this paper, the breakup dynamics of toroidal droplets in immiscible viscous oils have been numerically investigated. A two-dimensional model combined level-set method is proposed. Numerical results reveal that the initial aspect ratios, interfacial tensions, and outer liquid viscosities play important roles in determining the breakup dynamics of toroidal droplets. The initial aspect ratios dominate the number of split droplets, which is consistent with a linearly scaling law n = 0.57 R0/a0. By considering key factors of interfacial tension in this process, it is found that interfacial tension is crucial in the initial morphology of the toroidal droplet and helps to retard the unstable breakup dynamics. Interestingly, reducing the interfacial tension stabilizes it against breakup. We further study the effect of viscosity on the breakup dynamics. The surrounding viscous oils contribute to stabilizing the interfacial-tension-driven instabilities and extending the breakup time. Thus, for a toroidal droplet in high viscosity oils and a sufficiently low interfacial tension system, the unstable breakup dynamics could be delayed. Our findings provide a novel fundamental understanding of toroidal droplets and are beneficial to applications involving the manipulation of toroidal droplets.
Magnetization reversal, critical behavior, and magnetocaloric effect in NdMnO3: The role of magnetic ordering of Nd and Mn moments
Authors: Wang Yan , Wang Haiou , Tan Weishi , Huo Dexuan
Published: November 2022

The magnetic properties, critical behavior, and magnetocaloric effect of perovskite NdMnO3 are studied. The Nd ordering is induced by the Mn ferromagnetic component with antiferromagnetic coupling with each other and then magnetization reversal occurs due to Mn moments reorientation induced by the ordering Nd moments, which explains the phenomenon of negative magnetization at low temperatures. The critical behavior of NdMnO3 is studied using Kouvel–Fisher and self-consistent methods. The results show that the Kouvel–Fisher method is reliable and critical exponents are coming out as β = 0.462 for TC = 11.15 K, γ = 1.041 for TC = 11.42 K, δ = 3.252 by critical isotherm analysis. Magnetic exchange distance may decay as J(r)≈r−4.563, that is, somewhere between the three-dimensional Heisenberg model and the mean field model. Remarkably, three temperature transitions and the corresponding three extremum values including positive and negative entropy change are observed in NdMnO3, which is different from previous reports on NdMnO3. A positive entropy change as 3.82 J/kg K at 10–15 K for μ0ΔH = 50 kOe and a negative entropy change as −0.557 J/kg K at around 8 K for μ0ΔH = 5 kOe are found, which can be put down to a fast magnetization change of NdMnO3 because of the Nd moments ordering and Mn moments reorientation. Besides, an entropy change of 1.22 J/kg K is found for μ0ΔH = 50 kOe at 80–85 K, which is corresponding to the Mn ferromagnetic ordering temperature. The relative cooling power of NdMnO3 reaches 105.9 J/kg, making it a promising candidate in the field of magnetic refrigeration.
Acoustic characteristics of a cylindrical shell coupled to an acoustic cavity under complex excitations
Authors: Yuan Suwei , Zhu Haichao , Hou Jiuxiao , Liao Jinlong
Published: November 2022

In this research, we analyze the acoustic–vibration coupling of liquid-filled cylindrical shells under complex excitations. A calculation model to determine the acoustic characteristics and steady-state response of a cylindrical shell coupled to an acoustic cavity is proposed. The displacement and sound pressure of the cylindrical shell are described by a Chebyshev–Fourier series in three dimensions. The uncertain expansion coefficient is determined with a Rayleigh–Ritz model. The accuracy and convergence of this method are compared with those of the finite element method. The spring constraint is applied to simulate arbitrary boundary parameters. The impact of these parameters on the coupled natural frequency is analyzed. Finally, the steady-state response of a coupled system for various excitation parameters is analyzed.
Adaptive light-sheet fluorescence microscopy with a deformable mirror for video-rate volumetric imaging
Authors: Hong Wenzhi , Wright Terry , Sparks Hugh , Dvinskikh Liuba , MacLeod Ken , Paterson Carl , Dunsby Chris
Published: November 2022

Light-sheet fluorescence microscopy (LSFM) achieves optically sectioned imaging with the relatively low photobleaching and phototoxic effect. To achieve high-speed volumetric LSFM imaging without perturbing the sample, it is necessary to use some form of remote refocusing in the detection beam path. Previous work used electrically tunable lenses, tunable acoustic gradient index of refraction lenses, or the remote-refocusing approach of Botcherby et al. [Opt. Lett. 32(14), 2007 (2007)] to achieve remote refocusing. However, these approaches generally only provide low-order defocus correction, which is not compatible with higher-NA objectives that require higher order defocus corrections or reduce the optical throughput. In order to simultaneously achieve high-speed remote refocusing and correct system aberrations, we employ a deformable mirror in the detection path that is capable of providing higher orders of defocus and aberration correction in an optical system with an NA of 0.72–0.75. We demonstrate high-speed volumetric imaging at 26.3 volumes per second and 35 frames per volume for a defocus range of −50 to 50 μm.
Resolved-sideband micromotion sensing in Yb+ on the 935 nm repump transition
Authors: Goham Connor J. B. , Britton Joseph W.
Published: November 2022

Ions displaced from the potential minimum in an RF Paul trap exhibit excess micromotion. A host of well-established techniques are routinely used to sense (and null) this excessive motion in applications ranging from quantum computing to atomic clocks. The rich atomic structure of Yb+, a heavy ion, includes low-lying 2D3/2 states that must be repumped to permit Doppler cooling, typically using a 935 nm laser coupled to the 3D[3/2]1/2 states. In this article, we demonstrate the use of this transition to make resolved-sideband measurements of 3D micromotion in 172Yb+ and 171Yb+ ions. Relative to other sensing techniques, our approach has very low technical overhead and is distinctively compatible with surface-electrode ion traps.
N,S-Chelating triazole-thioether palladium for the one-pot synthesis of biaryls
Authors: Yan Qiong , Huang Heng , Si Xiang
Published: November 2022

In this work, for the one-pot two-step coupling reaction of aryl halides with bis(pinacol)diboron, we first applied a phosphorus-free N,S-chelated triazole sulfide palladium-catalyzed system. At the same time, we also carried out careful ligand design to explore the effect of the environment around the coordinating sulfur atom on the reaction. Experiments have shown that the N2-thioether substituted 1,2,3-triazlole palladium is an optimal catalyst The reaction could also reach up to quantitative yield in 4 h with only 1 mol% catalyst. Moreover, some low-activity aryl chlorides can also be coupled with bis(pinacolato)diboron under this catalytic system. We were able to obtain biaryls containing various functional groups in good to excellent yields.
Closing a biogeographic gap: a new pettalid genus from South Australia (Arachnida : Opiliones : Cyphophthalmi : Pettalidae) with a UCE-based phylogeny of Cyphophthalmi
Authors: Giribet Gonzalo , Shaw Matthew , Lord Arianna , Derkarabetian Shahan
Published: November 2022

Pettalidae is a family of mite harvestmen that inhabits the former circum-Antarctic Gondwanan terranes, including southern South America, South Africa, Madagascar, Sri Lanka, Australia and New Zealand. Australia is home to two pettalid genera, Austropurcellia, in northern New South Wales and Queensland, and Karripurcellia, in Western Australia, until now showing a large distributional gap between these two parts of the Australian continent. Here we report specimens of a new pettalid from South Australia, Archaeopurcellia eureka, gen. et sp. nov., closing this distributional gap of Australian pettalids. Phylogenetic analyses using traditional Sanger markers as well as ultra-conserved elements (UCEs) reveal that the new genus is related to the Chilean Chileogovea, instead of any of the other East Gondwanan genera. This relationship of an Australian species to a South American clade can be explained by the Antarctic land bridge between these two terranes, a connection that was maintained with Australia until 45 Ma. The UCE dataset also shows the promise of using museum specimens to resolve relationships within Pettalidae and Cyphophthalmi. ZooBank: urn:lsid:zoobank.org:pub:9B57A054-30D8-4412-99A2-6191CBD3BD7E
ER–endosome contacts master the ins and outs of secretory endosomes
Authors: Wenzel Eva Maria , Raiborg Camilla
Published: November 2022

What defines whether an endosome follows the degradative pathway or fuses with the plasma membrane to release exosomes? In this issue of JCB, Fredrik Verweij and colleagues (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202112032) demonstrate how secretory endosomes are guided by ER–endosome contacts to take a cellular detour and several identity transitions for efficient exosome release.
Production of twisted particles in heavy-ion collisions
Authors: Zou Liping , Zhang Pengming , Silenko Alexander J
Published: November 2022

A prevalence of production of twisted (vortex) particles in noncentral heavy-ion collisions is shown. In such collisions, photons emitted due to the rotation of charges are highly twisted. Charged particles are produced in nonspreading multiwave states and have significant orbital angular momenta. It can be expected that an emission of any twisted particles manifesting themselves in specific effects is rather ubiquitous.
Measurement of excitation functions for
nat
Cu(α, x) reactions with detailed covariance analysis
Authors: Choudhary Mahesh , Sharma Aman , Gandhi A , Singh Namrata , Dubey Punit , Upadhyay Mahima , Mishra Utkarsha , Dubey N K , Dasgupta S , Datta J , Katovsky K , Kumar A
Published: November 2022

The excitation functions of 66Ga, 67Ga, 65Zn and 64Cu radioisotopes produced via alpha-induced reaction on
nat
Cu were measured using a stacked foil activation method. The gamma-ray activity produced by the above mentioned radionuclides was measured using the HPGe detector. The covariance analysis was performed to quantify the measured cross-section uncertainties as well as the correlation between different alpha energy cross-sections. A covariance matrix and cross-sections for the
nat
Cu(α, x)66Ga,
nat
Cu(α, x)67Ga,
nat
Cu(α, x)65Zn and
nat
Cu(α, x)64Cu nuclear reactions in the projectile energy range of 15–37 MeV are reported in the present work. The measured reaction cross-sections are compared with the existing experimental data and theoretically simulated results from the TALYS code.
Amorphous Ni–Co binary hydroxide with super-long cycle life and ultrahigh rate capability as asymmetric supercapacitors
Authors: Li Hongbo , Zhou Xiaosong , Zhao Peng
Published: November 2022

Ni–Co binary hydroxide (Ni
x
Co1−x
(OH)2) with nanostructure is prepared by one-step electrochemical deposition process with de-ionized water as electrolyte. The molar ratio of Ni/Co for Ni
x
Co1−x
(OH)2 can be accurately controlled via changing the composition of the alloy target. A series of typical hydroxides are synthesized with Ni/Co molar ratios of 1:2, 1:3, 1:4, 1:6, 6:1, 4:1, 3:1, 2:1 and 1:1. The electrochemical performances of Ni
x
Co1−x
(OH)2 exhibit remarkable improvement in rate capability and cycling stability compared to monometallic hydroxide. Electrochemical test results reveal that Ni4/5Co1/5(OH)2 delivers the maximum specific capacitance of 2425 F g−1, while Ni0.5Co0.5(OH)2 exhibits ultrahigh rate capability (a 14% capacity decrease after a 100-fold increase in scan rate and 7% capacity decrease after a 40-fold increase in current density) and super-long cycle life (no capacitance loss after 50 000 cycles). Especially, the Ni0.5Co0.5(OH)2//AC supercapacitor exhibits a super-long cycle life with a 2% capacitance loss after 100 000 cycles, which is quite better than that of crystalline devices.
A detector block-pairwise dead time correction method for improved quantitation with a dedicated BrainPET scanner
Authors: Issa Ahlam Said Mohamad , Scheins Jürgen , Tellmann Lutz , Lopez-Montes Alejandro , Herraiz Joaquin L , Brambilla Cláudia Régio , Herzog Hans , Neuner Irene , Jon Shah N , Lerche Christoph
Published: November 2022

‘Objective. Dead time correction (DTC) is an important factor in ensuring accurate quantification in PET measurements. This is currently often achieved using a global DTC method, i.e., an average DTC factor is computed. For PET scanners designed to image dedicated organs, e.g., those used in brain imaging or positron emission mammography (PEM), a substantial amount of the administered radioactivity is located outside of the PET field-of-view (FOV). This activity contributes to the dead time (DT) of the scintillation detectors. Moreover, the count rates of the individual scintillation detectors are potentially very inhomogeneous due to the specific irradiation of each detector, especially for combined MR/PET systems, where radiation shields cannot be applied. Approach: We have developed a block-pairwise DTC method for our Siemens 3T MR BrainPET insert by extending a previously published method that uses the delayed random coincidence count rate to estimate the DT in the individual scans and planes (i.e., scintillation pixel rings). The method was validated in decay experiments using phantoms with a homogenous activity concentration and with and without out-of-FOV activity. Based on a three-compartment phantom, we compared the accuracy and noise properties of the block-pairwise DTC and the global DTC method. Main results. The currently used global DTC led to a substantial positive bias in regions with high activity; the block-pairwise DTC resulted in substantially less bias. The noise level for the block-pairwise DTC was comparable to the global DTC and image reconstructions without any DTC. Finally, we tested the block-pairwise DTC with a data set obtained from volunteer measurements using the mGluR5 (metabotropic glutamate receptor subtype 5) antagonist [11C]ABP688. When the relative differences in activity concentrations obtained with global DTC and block-pairwise DTC for the ACC and the cerebellum GM were compared, the ratios differed by a factor of up to 1.4 at the beginning—when the first injection is administered as a bolus with high radioactivity. Significance. In this work, global DTC was shown to have the potential to introduce quantification bias, while better quantitation accuracy was achieved with the presented block-pairwise DTC method. The method can be implemented in all systems that use the delayed window technique and is particulary expected to improve the quantiation accuracy of dedicated brain PET scanners due to their geometry.’
Transmission and multiple reflection mechanisms of guided streamers propagating through grounded annular electrode and interacting with grounded surface electrode
Authors: Decauchy H , Dufour T
Published: November 2022

The repeatable dynamics and the reversal propagation of guided streamers remains a major question of fundamental physics. In this article, trains of positive guided streamers are generated within an atmospheric pressure plasma jet supplied in helium and polarized by a high-voltage nanosecond pulse generator. The device is completed by two distant targets: a grounded annular electrode (GAEL) coaxially centered around the capillary through which guided streamers can propagate, and a grounded surface electrode (GSEL) on which they can interact. The resulting transmitted and multiple reflected guided streamers are measured combining optical characterization (fast intensified charge-coupled device (ICCD) imaging) and electrical characterization (high voltage probe and current monitors). While the electrical approach provides information on the capacitive/conductive nature of the current peaks as well as on their positive/negative value, fast ICCD imaging distinguishes whether the guided streamers are incident, reflected or transmitted. Combining these two techniques allow us to demonstrate experimentally that the reflected streamers are negative contrarily to the others. Besides, four types of reflections have been highlighted: a reflection (r) at the outlet of the capillary, a reflection on the GSEL (R) and two reflections (r′ and r″) observed when an incident guided streamer passes through the GAEL. The two techniques agree that the characteristic propagation times are always shorter for reflected negative streamers than for the positive ones propagating forward. Hence, for a GAEL placed 3 cm away from the high voltage electrode, propagation time is 80 ns for reflection versus 250 ns for transmission. These characteristic propagation times are even shorter when the annular electrode is brought closer to the surface electrode with velocities typically higher than 300 km s−1. In addition, the intensity ratios of reflected/incident guided currents drop sharply, typically losing one decade over a counter-propagation length of only 3–5 cm. Finally, all these experimental data are utilized to build an equivalent electrical model that allow to better understand the dynamics of the guided streamers and explain their transmission and reflection modes upon their interaction with the two distant grounded electrodes.
Space-charge affected current flow: an analytical verification solution for kinetic and fluid simulation models
Authors: Lafleur T
Published: November 2022

Verification of numerical simulations is an important step in code development as it demonstrates the correctness of the code in solving the underlying physical model. Analytical solutions represent a strong tool in code verification, but due to the complexity of the fundamental equations, such solutions are often not always available. This is particularly true in the case of kinetic models. Here we present a family of fully analytical solutions describing current transmission between two electrodes and which apply to both fluid, and kinetic, descriptions of the system. The solutions account for the finite initial particle injection velocity and are valid for all injection currents between zero and the maximum at the space-charge limit. In addition to determining this space-charge limited current, spatial profiles of all physical quantities (such as the particle density and velocity) are also obtained at all injection currents. This provides a means to not only verify fluid and kinetic simulations, but also to assess the error and accuracy of the numerical simulation methods and parameters used. The analytical solutions extend the classical Child–Langmuir law (which only applies to the maximum transmissible current and an initial injection velocity equal to zero), and provide new insight into space-charge affected current flow.
Analyzing spectral properties and sensing performance of multi-single-multi mode fiber combination
Authors: Dey Koustav , Roy Sourabh
Published: November 2022

Here, we have executed a comprehensive investigation on the impact of the single-mode fiber (SMF) lengths on the sensing performance of multi-single-multi mode (MSM) fiber segment combination under different external parameters including temperature, strain and refractive index. An experimental setup is proposed to demonstrate the efficacy in measuring the aforementioned variables with larger sensitivity along with the resolution over the large dynamic range. In addition, different phenomenal characteristics namely fast Fourier transform, fringe visibility, and the free spectral range of the observed transmission spectrum have also been analyzed meticulously. The achieved results show that the sensitivities increase with an increase of the SMF length and are restricted to 12 cm length due to the superimposing and less resolution of the probing dips beyond this. The highest sensitivities of 133.25 pm °C−1, −3.41 pm με
−1 and −52.10 nm/RIU for temperature, strain and refractive index, respectively are achieved for the 12 cm length of the SMF which assures potential employment of the proposed sensor in various sensing applications.
DC hopping photoconductivity via three-charge-state point defects in partially disordered semiconductors
Authors: Poklonski N A , Anikeev I I , Vyrko S A
Published: November 2022

The stationary (DC) hopping photoconductivity caused by the migration of electrons via intrinsic point t-defects of the same type with three charge states (−1, 0, and +1 in units of elementary charge) is theoretically studied. It is assumed that t-defects are randomly (Poissonian) distributed over a crystal and hops of single electrons occur only via t-defects in the charge states (−1), (0) and (0), (+1). Under the influence of intercenter illumination nonequilibrium charge states (−1) and (+1) of defects are generated due to photostimulated electron transitions between pairs of defects in the charge states (0). During the recombination of nonequilibrium charge states (−1) and (+1) of defects, pairs of defects in the charge states (0) are formed. It is assumed that illumination does not heat the crystal, i.e. does not increase the coefficient of thermal ionization of t-defects. The dependence of the ratio of photoconductivity to dark hopping electrical conductivity on the ratio of photoionization coefficient (γ) of neutral t-defects to coefficient of ‘capture’ (α) of an electron from a negatively charged to a positively charged t-defect is calculated. The calculations of hopping photoconductivity were carried out for the partially disordered silicon crystal with total concentration of t-defects of 3·1019 cm−3, compensated by shallow hydrogen-like donors. The ratios of donor concentration to t-defect concentration (compensation ratios) are 0.25, 0.5, and 0.75. It is taken into account that an electron localization radius on t-defect in the charge state (−1) is greater that on t-defect in the charge state (0). The calculated value of the dark hopping electrical conductivity is consistent with the known experimental data. A negative DC photoconduction at γ > α is predicted, due to a decrease in the concentration of electrons hopping via states (−1), (0) and (0), (+1).
Signal of cosmic strings in cross-correlation of 21-cm redshift and CMB polarization maps
Authors: Blamart Matteo , Fronenberg Hannah , Brandenberger Robert
Published: November 2022

We study the signal of cosmic string wakes present before the time of reionization in the cross-correlation signal of 21-cm redshift and B-mode CMB polarization maps. The specific non-Gaussian signal of strings in the position space cross-correlation maps can be extracted by means of a matched filtering analysis. Signals of strings with tension somewhat lower than those corresponding to the current upper bound can be identified when embedded in a background of Gaussian fluctuations from a Planck best-fit LCDM model.
Do you smell something decaying? Updated linear constraints on decaying dark matter scenarios
Authors: Alvi S. , Brinckmann T. , Gerbino M. , Lattanzi M. , Pagano L.
Published: November 2022

The stability of particles in the cosmic soup is an important property that can affect the cosmic evolution. In this work, we update the constraints on the decaying cold dark matter scenario, when the decay products are effectively massless. We assume, as a base case, that all of dark matter is unstable and it can decay on cosmological time scales. We then extend the analysis to include the scenario where only a fraction of dark matter is unstable, while the remaining part is composed of the standard, stable, dark matter. We consider observations of cosmological probes at linear scales, i.e., Planck 2018 cosmic microwave background temperature, polarization, and lensing measurements, along with geometrical information from baryon acoustic oscillation (BAO) measurements from SDSS DR7, BOSS DR12, eBOSS DR16 and 6dFGS, to derive conservative constraints on the dark matter decay rate. We consider these dataset separately, to asses the relative constraining power of each dataset, as well as together to asses the joint constraints. We find the most stringent upper limit on the decay rate of decaying cold dark matter particles to be ΓDCDM < 0.129 × 10-18 s-1 (or, equivalently, the dark matter lifetime τ
DCDM > 246 Gyr) at 95% C.L. for the combination of Planck primary anisotropies, lensing and BAO. We further explore one-parameter extensions of our baseline DCDM model. Namely, we vary the sum of neutrino masses, the curvature density parameter, and the tensor-to-scalar ratio along with the DCDM parameters. When varying the tensor-to-scalar ratio we also add data from the BICEP/Keck experiment.
Qualitative analysis for viscous cosmologies in a non linear regime of the Israel-Stewart formalism
Authors: Aguilar-Pérez Gilberto , Avilez-López Ana A. , Cruz Miguel
Published: November 2022

We explore the dynamical properties of a cosmological model that includes viscous effects in the dark matter sector of the fluid equations in a flat Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime. The bulk viscous effects are described by a non linear extension of the full Israel-Stewart model, which is a fluid causal scheme. We allow the interchange of energy in the dark sector and describe this by means of the interaction term, namely Q. We establish the dynamical system corresponding to Friedmann and fluid set of equations associated to the model and study the linear stability of its critical points. From the exploration of the dynamical system, we show the appearance of a critical point characterizing a de Sitter universe within the non interacting and interacting dark sector. We focus our study to analyse the stability of this fixed point in a large region of parameter space and derive linearized solutions around it. These approximate and analytical solutions are potentially able to describe the expansion of the universe since they are close to a de Sitter stationary solution. Within this regime with Q ≠ 0, we realize the existence of regions in the space of parameters where this critical point is stable and describes the behavior of dark energy as quintessence, cosmological constant and phantom like fluids. We perform a comparison between numerical and linearized solutions nearby the critical points within the full non linear regimes and also contrast them against ΛCDM model as a fiducial model. We find that the fully non linear regime is favored by observations and closer to the concordance model due to the non-zero value of the parameter j, which controls the non linear effects of bulk viscosity. In fact, at low redshift values, the expansion rate associated to the full non linear regime is practically indistinguishable from the ΛCDM model. The deceleration parameter obtained in this regime exhibits a transition from decelerated to accelerated cosmic expansion.