bluuebunny/crossref_metadata_2025 huggingface dataset:
Italian items in domestic spaces
Authors: Chianese Francesco
Published: May 2022

In their migration, people carry objects with them, and relocate them through physical spaces and across cultural boundaries. Handed down through generations, these objects become signs of ethnicity beyond their appearance and purpose. Examining the variety of the literary representations of objects and their subsequent translation contributes to the analysis of how material culture migrates within distant cultural systems and from one language to another. This essay focuses on domestic objects depicted by two Italian authors writing about the experience of a migrant coming-of-age in the United States: Helen Barolini and Chiara Barzini. Using diverse multilingual and (self-)translation strategies, they highlight through cultural translation the difficulties of bridging their Italian and American selfhood within an Italian household relocated abroad. In doing so, their relationship with objects underlines how their diasporic experience is entangled with their achievement of self-confidence and independence as women within the context of the Italian diaspora.
Influence of emitting nanoparticles concentration to the density of free electron in the thermal dusty plasma
Authors: Fairushin I. I.
Published: May 2022

On the basis of a statistical model describing the emission of electrons from the surface of dust particles in thermal plasma, a nonmonotonic character of the dependence of the concentration of emitted electrons on the concentration of grains has been established. The nature of the influence of the equilibrium temperature of the system and the size of dust particles on this effect is studied.
Justification of the choice of the optimal design of equipment for electrolyte-plasma polishing
Authors: Tazmeev B K , Sokolenko O N , Pogosyan V M , Tazmeeva R N
Published: May 2022

The article proposes a method of complex comparison of equipment for electrolyte-plasma polishing of surfaces. The Harrington function is used to evaluate the equipment. The values of the function are limited by the numerical interval 0.2 - 0.8. The parameters of the equipment are selected as the evaluation parameters: maximum polishing area per cycle, productivity, power, area occupied by the installation, cost. As a result of a comprehensive assessment, the best type of equipment for electrolyte-plasma polishing, which provides a resource-saving and energy-saving mode of operation was selected. A computer program has been developed with the help of which a generalized evaluation parameter has been calculated and a comparative analysis of the equipment has been performed.
The dependence of the surface roughness of aluminum nitride films on the processing methods when magnetron sputtering is used
Authors: Baranova L , Strunin V , Baysova B
Published: May 2022

The paper investigates the dependence of the surface roughness of aluminum nitride films on the modes of magnetron deposition. The paper shows the difference between the surfaces of polycrystalline aluminum nitride films on ceramized glass and silicon substrates grown under the same conditions. Atomic force microscopy was used to compare the surface roughness parameters of aluminum nitride obtained at different substrate temperatures and the power dissipation in the target. The optimal conditions for forming aluminum nitride films through magnetron sputtering have been determined.
STUDY OF THE EFFECT OF LOW-TEMPERATURE PLASMA BETWEEN ELECTROLYTIC ELECTRODES ON POLYMER SURFACES
Authors: Kayumov R R , Nizameev A A , Mardanov R R , Akhatov M F
Published: May 2022

In the modern world, polymers are used in almost all areas. Modification of polymer surfaces is an urgent task. Increasing adhesion and wettability is one of the important parameters. There are many different methods for increasing adhesion and wettability. The electrolytic plasma method is one of them. After processing the surface of the polymer by this method, the wettability of the surface of modified polymers with water was studied by measuring the size of a drop of technical water on the surface of the polymer. As a result of experimental studies, the modification of polyethylene terephthalate decreased the wetting angle by 11-24%.
Synthesis of Microdiamonds and Germanium Nanotubes In the Argon-Germanium Arc
Authors: Timerkaev B A , Abdullin A A , Suleimanov R M , Shaikhattarov R R , Gevorgyan R K
Published: May 2022

The paper describes a technique for the synthesis of microdiamonds, germanium nanoballs and nanotubes in an argon-germanium arc. The evaporation of germanium atoms was carried out from the surface of a graphite rod, which served as the anode of the arc discharge. The synthesis of microdiamonds was observed on graphite substrates near the anode; germanium nanotubes and germanium nanoballs were also found nearby. It has been established that germanium promotes the synthesis of nano and microdiamonds. Synthesized diamonds have a classic structure with rectangle faces and four hexagons adjacent to the edges of this rectangle. The sizes of microdiamonds reach tens of microns. The diameters of germanium nanotubes are of the order of 50-100 nm, and the length is of the order of 10 μm.
On the question of the applicability of the principle of thermodynamic similarity in liquid alkali metals
Authors: Tsygankov A A
Published: May 2022

In this paper, we have created an interparticle interaction potential for liquid alkali metals using ab-initio simulations and machine learning. The resulting family of potentials was tested by molecular dynamics simulation, in which the liquid metals were heated to the melting point and the resulting system was then averaged. The simulation results show that near the melting point, the radial distribution function and the static structure factor are reproduced. This results indicates that the principle of corresponding states is fulfilled in liquid alkali metals.
Structural transformations in binary Ni62Nb38 alloy at ultrahigh temperatures
Authors: Yarullin Dinar T. , Doronina Maria A.
Published: May 2022

In this study, we performed the molecular dynamics simulation of the binary Ni62Nb38 alloy at heating from 300 K to 9000 K. The temperature dependences of the density and the fraction of liquid atoms were calculated. The boiling temperature of the system is determined. It has been established that near the temperature 7000 K the system undergoes phase transition from liquid to gas phase. It is shown that near the boiling temperature, the molten metal forms a branched structure. The obtained results made it possible to estimate the region of the liquid phase and to determine the probable scenario for the occurrence of structural changes near the boiling point.
On the accuracy of analytical solution of the Poisson-Boltzmann equation in the linear approximation
Authors: Fairushin I. I.
Published: May 2022

In this paper, it is shown that the choice of the reference point of the potential for the Poisson-Boltzmann equation can affect the accuracy of the solution in the linear approximation.
Spatial distributions of X-ray radiation during ferrite surface breakdown
Authors: Andreev S N , Bernatskiy A V , Dushkin G A , Tskhai S N , Tilikin I N , Pikuz S A , Savinov S Y
Published: May 2022

Spatial properties of the radiation induced by a ferrite surface flashover supported by a 300 kV and ∼1 ns rise time pulsed voltage source were studied. Peak value and rise time were obtained for the discharge current.
Modification of the materials based on protein fibers in a low-pressure high-frequency plasma flow
Authors: Rakhmatullina G R , Pankova E A , Fukina O V , Khayytov M , Chapaeva L V
Published: May 2022

The effect of low-pressure high-frequency (HF) plasma treatment on the structure of the materials formed by bundles of natural protein (collagen) fibers is considered. The outer surface of the material is being affected by a constant flow of ions and a pulse-periodic flow of electrons. During this procedure the electrons flow at opposite sides of the sample in antiphase. This leads to that an alternating electric field is created, which intensity is estimated approximately at 105 V/m, inside the material. As a result, in the capillaries and pores, a breakdown occurs and charged particles are forming during this process. The recombination of these particles releases an energy of 15.76 eV on the surface of pores and capillaries, which is transferring to the surface molecules of the protein, which leads to the bulk modification of the material based on protein fibers. Such volumetric processing provides an effective modification of structural elements, allowing you to significantly improve the quality of liquid treatments in the production of collagen-containing materials and their properties in general.
Comparison of the Smallest Squares and Smallest Modules Methods in Modeling Processing of Materials by Plasma of a Gas-Vapor Discharge with Liquid Electrodes
Authors: Takseitov R R , Galimova R K , Yakupov Z Y
Published: May 2022

This paper describes the application of the least squares and least modulus methods to obtain the values of the power parameters of the central Lennard-Jones potential when modeling processes in the technology of processing materials with vapor-gas discharge plasma with a liquid electrode.
New approach for the identification of anisotropy material parameters using hydraulic bulge tests
Authors: Khalfallah A , Zoueghi SA , Fernandes JV
Published: May 2022

This paper put forwards a new method for the identification of the flow curves of anisotropic sheet metals using hydraulic bulge tests throughout circular and elliptical dies. This method is based on the membrane equilibrium equation, numerical simulation to derive the pole thickness and experimental data involving the measurement of only the polar deflection versus the applied hydraulic pressure curves. The experimental curves of four hydraulic bulge tests were obtained: one bulge test through circular die, and three bulge tests through elliptical dies, where the major axe of the elliptical die was oriented in three directions with respect the rolling direction of the sheet metal. These results were used in the identification of flow parameters and anisotropy coefficients of Hill48’ yield criterion. Then, FEA was utilized to perform sensitivity analysis of material parameters on the different hydraulic bulge test responses. The case study was a sheet metal of low carbon steel DC04. The identified material parameters were used in the numerical simulation of hydraulic bulge tests for the accuracy verification of the proposed method. It was shown a good agreement between model’s prediction and experimental results.
Investigation of the impact of process parameters on the layer formation of AlSi coated boron-manganese steel
Authors: He F , Merklein M
Published: May 2022

Hot stamping has established itself as a technology for manufacturing safety-relevant car body components. Its usage has found increased importance due to rising political and social pressure e.g. for improved fuel conservation. Due to reduced sheet thickness, hot stamping parts offer lightweight solutions while at the same time providing improved crash performance due to their high strength. Boron-manganese steel is commonly used in hot stamping processes. Due to hot scale formation during heat treatment and the subsequent forming process, additional coatings, typically AlSi-coatings, are applied. Since hot stamped parts are formed at temperatures of 600 °C to 800 °C no suitable lubricants have yet been found. This leads to increased friction and severe wear in the process, which negatively affect tool lifetime and overall part quality. Additionally, process temperatures influence the layer formation and surface roughness due to diffusion processes. A deeper process understanding is needed to acquire detailed knowledge of the resulting impact on tribological behavior. Within this study, the effect of coating thickness on the resulting layer is analyzed by comparing the resulting material composition and surface roughness. To this end, the layer formation and surface roughness are analyzed for two different layer thicknesses (AS150 and AS80) in relation to furnace temperature, holding time and heat up rate. Both are characterized by means of heating experiments conducted on an annealing furnace. The change in layer composition and surface roughness are determined via metallographic investigation and tactile measurement. The results of this study help to improve the process understanding of the tribological conditions within the hot stamping process and to develop future measures for reducing tool wear.
U-channel forming of an 7075-T6 in warm conditions
Authors: Royne S , Laurent H , Maillard A
Published: May 2022

The use of high mechanical strength aluminum coupled with the warm forming process makes it possible to replace certain steel parts in vehicles, thus reducing its mass and consequently greenhouse gas emissions. Warm forming of aluminum alloys requires heating the part between 150°C and 250°C to increase formability and reduce springback. In this study, a 7075-T6 alloy U-channel part was warm formed at 200°C in a short enough time to maintain the T6 state of the material. The process consisted of successively performing the heating by contact and stamping steps on the same mechanical press. From a thermomechanical characterization of the alloy in the temperature range between RT and 200°C and several strain rates, numerical simulations of the forming of the U-channel part were carried out using Abaqus. The experimental springbacks reduced with temperature were in agreement with the numerical simulations. An analysis of the conductivity and hardness of the material showed also that the 7075 keeps its T6 state until 10 s of warm forming.
Process Stability and Application of 1900 MPa Grade Press Hardening Steel with reduced Hydrogen Susceptibility
Authors: Rosenstock D , Gerber T , Castro Müller C , Stille S , Banik J
Published: May 2022

While 22MnB5 with aluminium silicon (AS) coating was established as the quasi-standard in press hardening many years ago, the need for steels that offer even higher strength is growing. These needs include corrosion protection of the automotive component and scale prevention during processing in hot forming lines. However, the processing of AS coated ultra-high strength steels involves demands for the furnace atmosphere. Reducing the hydrogen susceptibility and increasing the material strength at the same time was the driving force for the development of MBW 1900 + AS Pro. The paper focuses on the process stability of this steel concerning furnace and stamping parameters as well as the hydrogen induced cracking resistance under different dew points in the furnace atmosphere. In addition, the potential by means of different partial press hardening processes is presented. With tailored tempering, locally heated tools can be used to achieve soft areas in the part. Furthermore, the application potential of MBW 1900 + AS Pro in tailor welded blanks is shown.
Comparison of three different ductile damage models for deep drawing simulation of high-strength steels
Authors: Behrens B-A , Rosenbusch D , Wester H , Althaus P
Published: May 2022

High-strength steels are increasingly used in deep drawing for automotive parts due to their improved strength properties. To increase the formability and thus extend the process limits, a deep drawing process with additional force transmission has been developed. For a numerical optimisation of the considered process, an exact modelling of the failure behaviour is essential. The forming limit curve (FLC) is widely used to predict the onset of necking in sheet metal forming. However, the validity of the FLC is limited to the case of linear strain paths. Therefore, the scope of past investigations has been on failure modelling depending on the stress state. This article presents the experimental-numerical characterisation of the failure behaviour of the high-strength steels HCT600X and HX340LAD. Tensile tests with butterfly specimens were carried out under varying stress states and simulated with ABAQUS to parametrise the stress-based models Johnson-Cook (JC), Modified Mohr-Coulomb (MMC) and DF2016. An additional experiment was carried out to evaluate the models in terms of predicted outcome accuracies by comparing the onset of fracture in the simulation with the experimental findings. In future investigations, the improved damage modelling will be applied in a deep drawing simulation with additional force transmission to optimise the process design.
Analytical approach to damage prediction in incremental sheet metal forming
Authors: Bharti Sahil , Raneesh Deepu , Krishnaswamy Hariharan , Panigrahi Sushanta Kumar
Published: May 2022

Incremental sheet metal forming (ISF) is known to exhibit higher formability compared to conventional stamping. It is established that the mechanism of failure during ISF is by fracture occurring at higher effective strain than the local necking observed in traditional forming processes. The deformation limit in ISF is therefore estimated numerically using a suitable continuum damage model. However, simulation of incremental forming process including the damage model is often computationally expensive. In the present work, a simpler alternative combining finite element simulation and numerical solution outside finite element software is utilized. The finite element simulation is performed ignoring the damage model. The stress and strain history thus obtained in critical locations is utilized to estimate the damage evolution. The proposed method is useful when utilizing uncoupled continuum damage models. The proposed method is validated for typical cases by comparing it against the predictions from finite element method. Excellent correlation is observed between the proposed method and finite element simulation results.
Measurement of edge fracture strain of dual-phase steels by in-plane bending test
Authors: Masoumi Khalilabad M , Perdahcioğlu E S , Atzema EH , van den Boogaard AH
Published: May 2022

Edge ductility of dual phase steels is highly affected by the preparation of the edge and especially shear cutting has a detrimental effect on the formability. In this study, a novel in-plane bending test is used to characterize the edge ductility of dual-phase steels. Digital image correlation technique is employed to calculate the fracture strain along the edge in the desired material orientation. The proposed test setup isolates the material-dependent aspects, namely damage and hardening, from those resulting from testing procedure factors such as contact stresses and friction compared to conventional hole expansion capacity (HEC) test. The results show that the edge crack phenomenon depends on the material orientation.
Adjustment of fracture locus to improve edge crack resistance
Authors: Habibi Niloufar , Münstermann Sebastian
Published: May 2022

Edge crack sensitivity of advanced high strength steels is posing challenges in forming the sheets with shear-cut edges. In fact, cutting process reduces formability of material by leaving residual damage at the cut edges and makes it prone to edge cracking. The difficulty of the problem mainly lies in the complex loading path that sheets undergo through shear-cutting and the subsequent forming processes. In other words, the stress state evolves from pure-shear to plane-strain during cutting process and changes to mostly uniaxial tension during the following hole-expansion test. The present study aimed to investigate the physical mechanism underlying the formation of edge cracks. The overall aim of the study is to tailor an improved microstructural configuration leading to a significantly reduced edge crack sensitivity. As a first step in this process, an artificial fracture locus is iteratively identified which promises to improve edge crack resistance. In this regard, a dual phase steel was considered as reference material and its fracture locus was calibrated based on uncoupled Bai-Wierzbicki fracture model. The artificial fracture locus representing a virtual material with improved edge crack resistance changed in a way that lower residual damage was inherited from the cutting process, which consequently improved the hole-expansion ratio.
On the topology design of a mechanical heterogeneous specimen using geometric and material nonlinearities
Authors: Gonçalves M , Andrade-Campos A , Thuillier S
Published: May 2022

Material characterization and the calibration of constitutive models play an important role in the majority of the forming processes nowadays. For an accurate virtualization of the processes, the material mechanical behavior needs to be known a priori. The classical characterization procedure involves carrying out several standard mechanical tests to identify the required information about the material. However, this procedure turns out to be expensive and time-consuming. Heterogeneous mechanical tests have been used to overcome this issue. By providing richer information with a reduced number of tests, their use can enhance the actual material characterization process. This work aims at making a significant contribution towards this goal by designing a heterogeneous mechanical test using topology optimization. A specimen topology is obtained with a heterogeneous displacement field by applying the theory of compliant mechanisms. Due to the large displacements considered, a geometrically nonlinear finite element analysis and a topology optimization procedure are proposed. Material nonlinearity is taken into account as well, to design solutions closer to reality. An optimal mechanical test with a highly heterogeneous strain field is obtained and evaluated, considering its diversity, using mechanism theory and a mechanical indicator.
Metamodeling of a deep drawing process using conditional Generative Adversarial Networks
Authors: Link Patrick , Bodenstab Johannes , Penter Lars , Ihlenfeldt Steffen
Published: May 2022

Optimization tasks as well as quality predictions for process control require fast responding process metamodels. A common strategy for sheet metal forming is building fast data driven metamodels based on results of Finite Element (FE) process simulations. However, FE simulations with complex material models and large parts with many elements consume extensive computational time. Hence, one major challenge in developing metamodels is to achieve a good prediction precision with limited data, while these predictions still need to be robust against varying input parameters. Therefore, the aim of this study was to evaluate if conditional Generative Adversarial Networks (cGAN) are applicable for predicting results of FE deep drawing simulations, since cGANs could achieve high performance in similar tasks in previous work. This involves investigations of the influence of data required to achieve a defined precision and to predict e.g. wrinkling phenomena. Results show that the cGAN used in this study was able to predict forming results with an averaged absolute deviation of sheet thickness of 0.025 mm, even when using a comparable small amount of data.
Predicting Dynamic Process Limits in Progressive Die Sheet Metal Forming
Authors: Budnick D , Ghannoum A , Steinlehner F , Weinschenk A , Volk W , Huhn S , Melek W , Worswick M
Published: May 2022

Tool makers have a limited selection of tools and are afforded limited flexibility during progressive die try-outs when attempting to identify suitable process control parameters and optimize throughput. The performance of a given tooling design hinges on selecting a suitable stroke rate for the press. Cost efficiencies are realized when operating a press at higher stroke rates, but risk subjecting the sheet metal strip to larger, uncontrolled oscillations, which can lead to collisions and strip-misalignment during strip progression. Introducing active control to the strip feeder and lifters can offer increased flexibility to tool makers by allowing the strip progression to be fine-tuned to reduce strip oscillations at higher stroke rates. To alleviate uncertainties and assist in fine-tuning the process control parameters, machine learning models, such as an artificial neural network, are constructed to predict whether a given set of process parameters will lead to a collision or strip-misalignment during the strip progression. The machine learning models are trained using a dataset of FEA simulations which model the same progressive die operation using different process control inputs for the feeder, lifter and press. The machine learning models are shown to be capable of predicting the outcome of a given process permutation with a classification accuracy of about 87 % and assist in identifying the dynamic process limits in the progressive die operation.
Digital Twins in deep drawing for virtual tool commissioning and inline parameter optimization
Authors: Klingel Lars , Penter Lars , Mayer Philip , Ihlenfeldt Steffen , Verl Alexander
Published: May 2022

Fluctuating boundary conditions and the highly nonlinear process behavior of deep drawing operations make experience-based selection of suitable control parameters difficult. Nowadays, commissioning deep drawing tools, i.e., die spotting and identification of suitable control parameters for defect-free parts, is conducted on real world try-out presses. Transferring the tools to production machines entails adaption of these initial parameters. Once production is ramped up, any changes to material properties, lubrication and press behavior require continuous manual machine parameter tuning. Virtual tool commissioning and utilizing these simulation models in the production phase to adapt control parameters would reduce time and cost over the entire life cycle of the machine and the tool sets. The virtual representative, which provides services for a plant over several life cycle phases, is also referred to as Digital Twin. In this paper, the authors present a Digital Twin concept for deep drawing presses to predict the state of the system and optimize the control parameters during the production. The integration of all involved subsystems into one system simulation and its efficient calculation is the biggest challenge. The authors combine a virtual commissioning simulation tool with a finite element model to implement all relevant properties of the deep drawing press and the interaction of its subsystems. It is shown, how the idea of a system simulation makes predictions of system parameters specific to a production situation possible, and therefore, can help to select suitable control parameters that leads to a reduction of the error rate in deep drawing.
Advanced Springback Compensation Strategy through elimination of avoidable elastic strain energy
Authors: Birkert A , Zimmermann P , Hartmann B , Nowack M
Published: May 2022

The stamping of dimensionally accurate sheet metal body components still represents a huge challenge in the automotive industry. This is partly caused by the multi-stage production process which complicates the design of an appropriate compensation strategy dramatically. A key prerequisite of an appropriate compensation strategy is to eliminate any undesired influence of elastic energy being potentially induced when closing the blankholders in the several operations throughout the production process. Here, a universally applicable compensation strategy is presented which fulfils this requirement thoroughly; by applying this process, the involved strain energy is reduced to a minimum due to proper part position in all operations. Technically this compensation strategy is achieved by, first, simulating all operations of the stamping process individually, second, by individually calculating the springback after each operation and, third, by accumulating the calculated deviation vector fields for each operation appropriately, which are then used for springback compensation. The process is time and cost effective and the required efforts are moderate even for complicated multistage stamping operations.
Superposing tensile stresses into single point incremental forming to affect martensitic transformation of SS304
Authors: Mamros E M , Maaß F , Hahn M , Tekkaya A E , Ha J , Kinsey B L
Published: May 2022

Superposing pre-stress on a SS304 sheet metal blank in biaxial tension and performing a single point incremental forming operation on the stretched blank is investigated experimentally. By applying a pre-stress to the sheet metal blank prior to incremental forming, the resulting microstructural change can be affected to obtain functionally graded materials according to the intended application. In austenitic stainless steels, this variation of the stress states alters the phase transformation, specifically the martensitic transformation kinetics, by influencing key process parameters, such as process force, temperature, and equivalent plastic strain. The phase transformation in truncated square pyramids is measured using magnetic induction. These measurements validate the effectiveness of the stress superposition method for achieving the desired mechanical properties based on altering the final microstructure of a simple geometry.
Evaluation of electronic and optical behavior of the interface of Co2FeAl/AlN heusler alloy
Authors: Lahoupour F , Boochani A
Published: May 2022

Based on the density functional theory, the electronic, optical, and structural properties of the Co2FeAl/AlN Interface have been studied. It is shown that the Co2FeAl compound is a half-metal with 100% spin polarization at the Fermi level, and the growth of this compound on the AlN semiconductor changes its stability. The best interface connection from the point of view of stability occurs in the Co-Co-Al case, which has a semi-metallic and spin polarization of the interface, which candidate it for spintronic applications. The optical properties of this interface show that it can benefit medical and sensor devices because of its anisotropic optical properties at low energies. In the infrared, visible, and ultraviolet ranges, the optical energy loss functions are zero or very little, which referred to its candidate for optical applications in these energy ranges.
Self-organized nanoscale networks: are neuromorphic properties conserved in realistic device geometries?
Authors: Heywood Zachary , Mallinson Joshua , Galli Edoardo , Acharya Susant , Bose Saurabh , Arnold Matthew , Bones Philip , Brown Simon
Published: May 2022

Self-organised nanoscale networks are currently under investigation because of their potential to be used as novel neuromorphic computing systems. In these systems, electrical input and output signals will necessarily couple to the recurrent electrical signals within the network that provide brain-like functionality. This raises important questions as to whether practical electrode configurations and network geometries might influence the brain-like dynamics. We use the concept of criticality (which is itself a key charactistic of brain-like processing) to quantify the neuromorphic potential of the devices, and find that in most cases criticality, and therefore optimal information processing capability, is maintained. In particular we find that devices with multiple electrodes remain critical despite the concentration of current near the electrodes. We find that broad network activity is maintained because current still flows through the entire network. We also develop a formalism to allow a detailed analysis of the number of dominant paths through the network. For rectangular systems we show that the number of pathways decreases as the system size increases, which consequently causes a reduction in network activity.
Dietary Inorganic Nitrate/Nitrite Supplementation Reduces Central and Peripheral Blood Pressure in Patients With Type 2 Diabetes Mellitus
Authors: Bock Joshua M , Hughes William E , Ueda Kenichi , Feider Andrew J , Hanada Satoshi , Casey Darren P
Published: May 2022

BACKGROUND

Patients with type 2 diabetes mellitus (T2DM) have increased cardiovascular risk due to elevated blood pressure (BP). As low levels of nitric oxide (NO) may contribute to increased BP, we determined if increasing NO bioavailability via eight weeks of supplementation with beetroot juice containing inorganic nitrate/nitrite (4.03 mmol nitrate, 0.29 mmol nitrite) improves peripheral and central BP relative to nitrate/nitrite-depleted beetroot juice.

METHODS

Peripheral and central BP were assessed at heart-level in supine subjects using a brachial artery catheter and applanation tonometry, respectively.

RESULTS

Nitrate/nitrite supplementation reduced peripheral systolic BP (148 ± 16 to 142 ± 18 mm Hg, P < 0.05) but not placebo (150 ± 19 to 149 ± 17 mm Hg, P = 0.93); however, diastolic BP was unaffected (supplement-by-time P = 0.08). Central systolic BP (131 ± 16 to 127 ± 17 mm Hg) and augmented pressure (13.3 ± 6.6 to 11.6 ± 6.9 mm Hg, both P < 0.05) were reduced after nitrate/nitrite, but not placebo (134 ± 17 to 135 ± 16 mm Hg, P = 0.62; 14.1 ± 6.6 to 15.2 ± 7.4 mm Hg, P = 0.20); central diastolic BP was unchanged by the interventions (supplement-by-time P = 0.16). Inorganic nitrate/nitrite also reduced AIx (24.3 ± 9.9% to 21.0 ± 9.6%) whereas no changes were observed following placebo (24.6 ± 9.3% to 25.6 ± 9.9%, P = 0.46).

CONCLUSIONS

Inorganic nitrate/nitrite supplementation improves peripheral and central BP as well as AIx in T2DM.

CLINICAL TRIALS REGISTRATION

Trial Number NCT02804932.
Vagueness and Kataleptic Impressions
Authors: Vogt Katja Maria
Published: May 2022

The Stoics’ theory of kataleptic impressions looks different once we attend to their analysis of the Sorites paradox. In defending this view, I reject the long-standing assumption that the Stoics develop their theory by focusing on sensory impressions. The Stoic approach to vagueness shows, for example, that non-sensory impressions can be seemingly indistinguishable by belonging to a series. It also draws attention to an understudied dimension of Stoic theory: in aiming to assent only to kataleptic impressions, one aims to avoid not only assent to false impressions but also assent to those that are neither true nor false.
STracking: a free and open-source Python library for particle tracking and analysis
Authors: Prigent Sylvain , Valades-Cruz Cesar Augusto , Leconte Ludovic , Salamero Jean , Kervrann Charles
Published: May 2022

Analysis of intra- and extracellular dynamic like vesicles transport involves particle tracking algorithms. The design of a particle tracking pipeline is a routine but tedious task. Therefore, particle dynamics analysis is often performed by combining several pieces of software (filtering, detection, tracking, etc.) requiring many manual operations, and thus leading to poorly reproducible results. Given the new segmentation tools based on deep learning, modularity and interoperability between software have become essential in particle tracking algorithms. A good synergy between a particle detector and a tracker is of paramount importance. In addition, a user-friendly interface to control the quality of estimated trajectories is necessary. To address these issues, we developed STracking, a Python library that allows combining algorithms into standardized particle tracking pipelines.

Availability and implementation

STracking is available as a Python library using ‘pip install’ and the source code is publicly available on GitHub (https://github.com/sylvainprigent/stracking). A graphical interface is available using two napari plugins: napari-stracking and napari-tracks-reader. These napari plugins can be installed via the napari plugins menu or using ‘pip install’. The napari plugin source codes are available on GitHub (https://github.com/sylvainprigent/napari-tracks-reader, https://github.com/sylvainprigent/napari-stracking).

Supplementary information

Supplementary data are available at Bioinformatics online.
Bone morphogenetic protein 2- and estradiol-17β-induced changes in ovarian transcriptome during primordial follicle formation
Authors: Chakraborty Prabuddha , Anderson Rebecca L , Roy Shyamal K
Published: May 2022

Estradiol-17β has been shown to promote primordial follicle formation and to involve bone morphogenetic protein 2 (BMP2) as a downstream effector to promote primordial follicle in hamsters. However, the molecular mechanism whereby these factors regulate ovarian somatic cells to pre-granulosa cells transition leading to primordial follicle formation remains unclear. The objective of this study was to determine whether BMP2 and/or estradiol-17β would regulate the expression of specific ovarian transcriptome during pre-granulosa cells transition and primordial follicle formation in the mouse ovary. BMP2 mRNA level increased during the period of primordial follicle formation with the concurrent presence of BMP2 protein in ovarian somatic cells. Estradiol-17β but not BMP2 exposure led to increased expression of ovarian BMP2 messenger RNA (mRNA), and the effect of estradiol-17β could not be suppressed by 4-[6-[4-(1-Piperazinyl)phenyl]pyrazolo[1,5-a]pyrimidin-3-yl]quinoline dihydrochloride (LDN) 193189. BMP2 or estradiol-17β stimulated primordial follicle formation without inducing apoptosis. Ribonucleic acid-sequence analysis (RNA-seq) of ovaries exposed to exogenous BMP2 or estradiol-17β revealed differential expression of several thousand genes. Most of the differentially expressed genes, which were common between BMP2 or estradiol-17β treatment demonstrated concordant changes, suggesting that estradiol-17β and BMP2 affected the same set of genes during primordial follicle formation. Further, we have identified that estradiol-17β, in cooperation with BMP2, could affect the expression of three major transcription factors, GATA binding protein 2, GATA binding protein 4 and Early growth response 2, and one serine protease, hepsin, in pre-granulosa cells during primordial follicle formation. Taken together, results of this study suggest that estradiol-17β and BMP2 may regulate ovarian gene expression that promote somatic cells to pre-granulosa cells transition and primordial follicle formation in the mouse ovary.
Intraoperative microseizure detection using a high-density micro-electrocorticography electrode array
Authors: Sun James , Barth Katrina , Qiao Shaoyu , Chiang Chia-Han , Wang Charles , Rahimpour Shervin , Trumpis Michael , Duraivel Suseendrakumar , Dubey Agrita , Wingel Katie E. , Rachinskiy Iakov , Voinas Alex E. , Ferrentino Breonna , Southwell Derek G. , Haglund Michael M. , Friedman Allan H. , Lad Shivanand P. , Doyle Werner K. , Solzbacher Florian , Cogan Gregory , Sinha Saurabh R. , Devore Sasha , Devinsky Orrin , Friedman Daniel , Pesaran Bijan , Viventi Jonathan
Published: May 2022

One-third of epilepsy patients suffer from medication-resistant seizures. While surgery to remove epileptogenic tissue helps some patients, 30–70% of patients continue to experience seizures following resection. Surgical outcomes may be improved with more accurate localization of epileptogenic tissue. We have previously developed novel thin-film, subdural electrode arrays with hundreds of microelectrodes over a 100–1000 mm2 area to enable high-resolution mapping of neural activity. Here, we used these high-density arrays to study microscale properties of human epileptiform activity. We performed intraoperative micro-electrocorticographic recordings in nine patients with epilepsy. In addition, we recorded from four patients with movement disorders undergoing deep brain stimulator implantation as non-epileptic controls. A board-certified epileptologist identified microseizures, which resembled electrographic seizures normally observed with clinical macroelectrodes. Recordings in epileptic patients had a significantly higher microseizure rate (2.01 events/min) than recordings in non-epileptic subjects (0.01 events/min; permutation test, P = 0.0068). Using spatial averaging to simulate recordings from larger electrode contacts, we found that the number of detected microseizures decreased rapidly with increasing contact diameter and decreasing contact density. In cases in which microseizures were spatially distributed across multiple channels, the approximate onset region was identified. Our results suggest that micro-electrocorticographic electrode arrays with a high density of contacts and large coverage are essential for capturing microseizures in epilepsy patients and may be beneficial for localizing epileptogenic tissue to plan surgery or target brain stimulation.
A connectivity model of the anatomic substrates underlying Gerstmann syndrome
Authors: Shahab Qazi S. , Young Isabella M. , Dadario Nicholas B. , Tanglay Onur , Nicholas Peter J. , Lin Yueh-Hsin , Fonseka R. Dineth , Yeung Jacky T. , Bai Michael Y. , Teo Charles , Doyen Stephane , Sughrue Michael E.
Published: May 2022

The Gerstmann syndrome is a constellation of neurological deficits that include agraphia, acalculia, left–right discrimination and finger agnosia. Despite a growing interest in this clinical phenomenon, there remains controversy regarding the specific neuroanatomic substrates involved. Advancements in data-driven, computational modelling provides an opportunity to create a unified cortical model with greater anatomic precision based on underlying structural and functional connectivity across complex cognitive domains. A literature search was conducted for healthy task-based functional MRI and PET studies for the four cognitive domains underlying Gerstmann’s tetrad using the electronic databases PubMed, Medline, and BrainMap Sleuth (2.4). Coordinate-based, meta-analytic software was utilized to gather relevant regions of interest from included studies to create an activation likelihood estimation (ALE) map for each cognitive domain. Machine-learning was used to match activated regions of the ALE to the corresponding parcel from the cortical parcellation scheme previously published under the Human Connectome Project (HCP). Diffusion spectrum imaging-based tractography was performed to determine the structural connectivity between relevant parcels in each domain on 51 healthy subjects from the HCP database. Ultimately 102 functional MRI studies met our inclusion criteria. A frontoparietal network was found to be involved in the four cognitive domains: calculation, writing, finger gnosis, and left–right orientation. There were three parcels in the left hemisphere, where the ALE of at least three cognitive domains were found to be overlapping, specifically the anterior intraparietal area, area 7 postcentral (7PC) and the medial intraparietal sulcus. These parcels surround the anteromedial portion of the intraparietal sulcus. Area 7PC was found to be involved in all four domains. These regions were extensively connected in the intraparietal sulcus, as well as with a number of surrounding large-scale brain networks involved in higher-order functions. We present a tractographic model of the four neural networks involved in the functions which are impaired in Gerstmann syndrome. We identified a ‘Gerstmann Core’ of extensively connected functional regions where at least three of the four networks overlap. These results provide clinically actionable and precise anatomic information which may help guide clinical translation in this region, such as during resective brain surgery in or near the intraparietal sulcus, and provides an empiric basis for future study.
Effectiveness of Heterologous Coronavirus Disease 2019 (COVID-19) Vaccine Booster Dosing in Brazilian Healthcare Workers, 2021
Authors: Marra Alexandre R , Miraglia João Luiz , Malheiros Daniel Tavares , Guozhang Yang , Teich Vanessa Damazio , da Silva Victor Elivane , Rebello Pinho João Renato , Cypriano Adriana , Vieira Laura Wanderly , Polonio Miria , Ornelas Rafael Herrera , de Oliveira Solange Miranda , Borges Junior Flavio Araujo , Oler Silvia Cristina Cassiano , Schettino Guilherme de Paula Pinto , de Oliveira Ketti Gleyzer , Ferraz Santana Rúbia Anita , de Mello Malta Fernanda , Amgarten Deyvid , Boechat Ana Laura , Trecenti Noelly Maria Zimpel , Kobayashi Takaaki , Salinas Jorge L , Edmond Michael B , Rizzo Luiz Vicente
Published: May 2022

Background

Little is currently known about vaccine effectiveness (VE) for either 2 doses of Oxford-AstraZeneca (ChAdOx1) viral vector vaccine or CoronaVac (Instituto Butantan) inactivated viral vaccine followed by a third dose of mRNA vaccine (Pfizer/BioNTech) among healthcare workers (HCWs).

Methods

We conducted a retrospective cohort study among HCWs (aged ≥18 years) working in a private healthcare system in Brazil from January to December 2021. VE was defined as 1 – incidence rate ratio (IRR), with IRR determined using Poisson models with the occurrence of laboratory-confirmed coronavirus disease 2019 (COVID-19) infection as the outcome, adjusting for age, sex, and job type. We compared those receiving viral vector or inactivated viral primary series (2 doses) with those who received an mRNA booster.

Results

A total of 11 427 HCWs met the inclusion criteria. COVID-19 was confirmed in 31.5% of HCWs receiving 2 doses of CoronaVac vaccine versus 0.9% of HCWs receiving 2 doses of CoronaVac vaccine with mRNA booster (P < .001) and 9.8% of HCWs receiving 2 doses of ChAdOx1 vaccine versus 1% among HCWs receiving 2 doses of ChAdOx1 vaccine with mRNA booster (P < .001). In the adjusted analyses, the estimated VE was 92.0% for 2 CoronaVac vaccines plus mRNA booster and 60.2% for 2 ChAdOx1 vaccines plus mRNA booster, when compared with those with no mRNA booster. Of 246 samples screened for mutations, 191 (77.6%) were Delta variants.

Conclusions

While 2 doses of ChAdOx1 or CoronaVac vaccines prevent COVID-19, the addition of a Pfizer/BioNTech booster provided significantly more protection.
Lead complications after cardiac surgery in patients with cardiac implantable electronic devices
Authors: Frausing Maria Hee Jung Park , Nielsen Jens Cosedis , Johansen Jens Brock , Jørgensen Ole Dan , Kristensen Jens , Olsen Thomas , Gerdes Christian , Kronborg Mads Brix
Published: May 2022

OBJECTIVES

Manipulation of the heart during cardiac surgery in patients with cardiac implantable electronic devices (CIEDs) may result in lead damage or displacement, but whether cardiac surgery truly infers an excess risk of lead failure is not known. The objective of this study was to examine the risk of lead complications after cardiac surgery in patients with CIEDs.

METHODS

We conducted a nationwide nested case–control study. The source population comprised all Danish patients ≥18 of age who underwent a de novo CIED implantation during 1998–2017. For inclusion, patients had to be alive and event free 6 months after implantation. Cases were matched 1:30 to controls on time, age, sex, and device type using risk set sampling. We used conditional logistic regression to estimate incidence rate ratios (IRRs) for the association between cardiac surgery and lead-related reoperation.

RESULTS

Our final population consisted of 67 621 patients. We identified 1437 (2.1%) incident cases of lead-related reoperations and 42 698 controls. Risk of lead complications was highest within 6 months of cardiac surgery [IRR 9.7, 95% confidence interval (CI) 6.3–14.8, adjusted IRR 9.6, 95% CI 6.2–14.7], and at 1 year, the relative risk of lead-related reoperation was close to unity (adjusted IRR 1.2, 95% CI 0.8–1.7).

CONCLUSIONS

Cardiac surgery was associated with a considerable risk of lead complications in patients with de novo CIEDs.