Filament Size Research Articles

High-throughput super-resolution analysis of influenza virus pleomorphism reveals insights into viral spatial organization.

Many viruses form highly pleomorphic particles. In influenza, virion structure is of interest not only in the context of virus assembly, but also because pleomorphic variations may correlate with infectivity and pathogenicity. We have used fluorescence super-resolution microscopy combined with a rapid automated analysis pipeline, a method well-suited to the study of large numbers of pleomorphic structures, to image many thousands of individual influenza virions; gaining information on their size, morphology and the distribution of membrane-embedded and internal proteins. We observed broad phenotypic variability in filament size, and Fourier transform analysis of super-resolution images demonstrated no generalized common spatial frequency patterning of HA or NA on the virion surface, suggesting a model of virus particle assembly where the release of progeny filaments from cells occurs in a stochastic way. We also showed that viral RNP complexes are located preferentially within Archetti bodies when these were observed at filament ends, suggesting that these structures may play a role in virus transmission. Our approach therefore offers exciting new insights into influenza virus morphology and represents a powerful technique that is easily extendable to the study of pleomorphism in other pathogenic viruses.

Topiramate affords neuroprotection in diabetic neuropathy model via downregulating spinal GFAP/inflammatory burden and improving neurofilament production

The current study aimed to test the neuroprotective action of topiramate in mouse peripheral diabetic neuropathy (DN) and explored some mechanisms underlying this action. Mice were assigned as vehicle group, DN group, DN + topiramate 10-mg/kg and DN + topiramate 30-mg/kg. Mice were tested for allodynia and hyperalgesia and then spinal cord and sciatic nerves specimens were examined microscopically and neurofilament heavy chain (NEFH) immunostaining was performed. Results indicated that DN mice had lower the hotplate latency time (0.46-fold of latency to licking) and lower von-Frey test pain threshold (0.6-fold of filament size) while treatment with topiramate increased these values significantly. Sciatic nerves from DN control mice showed axonal degeneration while spinal cords showed elevated GFAP (5.6-fold) and inflammatory cytokines (∼3- to 4-fold) but lower plasticity as indicated by GAP-43 (0.25-fold). Topiramate produced neuroprotection and suppressed spinal cord GFAP/inflammation but enhanced GAP-43. This study reinforces topiramate as neuroprotection and explained some mechanisms included in alleviating neuropathy.

Self-Compliant Threshold Switching Devices with High On/Off ratio by Control of Quantized Conductance in Ag Filaments

Threshold switches based on conductive metal bridge devices are useful as selectors to block sneak leakage paths in memristor arrays used in neuromorphic computing and emerging nonvolatile memory. We demonstrate that control of Ag-cation concentration in Al2O3 electrolyte and Ag filament size and density play an important role in the high on/off ratio and self-compliance of metal-ion-based volatile threshold switching devices. To control Ag-cation diffusion, we inserted an engineered defective graphene monolayer between the Ag electrode and the Al2O3 electrolyte. The Ag-cation migration and the Ag filament size and density are limited by the pores in the defective graphene monolayer. This leads to quantized conductance in the Ag filaments and self-compliance resulting from the formation and dissolution of the Ag conductive filament.

Continuous and highly accurate multi-material extrusion-based bioprinting with optical coherence tomography imaging.

Extrusion-based bioprinting is a widely used approach to construct artificial organs or tissues in the medical fields due to its easy operation and good ability to combine multimaterial. Nevertheless, the current technology is limited to some printing errors when combining multi-material printing, including mismatch between printing filaments of different materials and error deposited materials (e.g., under-extrusion and overextrusion). These errors will affect the function of the printed structure (e.g., mechanical and biological properties), and the traditional manual correction methods are inefficient in time and material, so an automatic procedure is needed to improve multimaterial printing accuracy and efficiency. However, to the best of our knowledge, very few automated procedure can achieve the registration between printing filaments of different materials. Herein, we utilized optical coherence tomography (OCT) to monitor printing process and presented a multi-material static model and a time-related control model in extrusion-based multi-material bioprinting. Specifically, the multi-material static model revealed the relationship between printed filament metrics (filament size and layer thickness) and printing parameters (printing speeds or pressures) with different materials, which enables the registration of printing filaments by rapid selection of printing parameters for the materials, while time-related control model could correct control parameters of nozzles to reduce the material deposition error at connection point between nozzles in a short time. According to the experimental results of singlelayer scaffold and multi-layer scaffold, material deposition error is eliminated, and the same layer thickness between different materials of the same layer is achieved, which proves the accuracy and practicability of these models. The proposed models could achieve improved precision of printed structure and printing efficiency.

Simulation on pull-out performance of steel bar from 3D-printed concrete

In this study, a finite element (FE) model for the pull-out test was established and verified to examine the influence of printed concrete-to-concrete interfaces on the pull-out performance of steel bar from 3D-printed concrete. The stress transfer, debonding process, and failure mechanism of 3D-printed specimen were revealed by detailed interfacial stress analysis. Moreover, the effects of the interfacial bond strength, filament size, angle between the steel bar and the printing direction (α), and bond length on the pull-out performance were intensively investigated. The numerical results showed that the failure pattern changed from the conventional pull-out failure to interfacial bond failure induced by 3D-printed concrete-to-concrete interfaces. Compared with the pull-out specimen with α = 0°, the peak load of pull-out specimen with α = 90° increases by 9.6%, which became the weakest when angle α = 30°. Moreover, the failure mode was observed to be influenced by the relative strength of the interlayer and interstrip interfaces and their distributions.

Influence of filament number and size on the basic properties of in situ made MgB2 wires

Monel-sheathed MgB2 wires with 6, 18 and 54 filaments of diameter 0.83 mm manufactured by Sam Dong Co., Ltd, have been subjected to twisting, drawing and rolling and measurements at low temperatures. R(T), I–V characteristics, critical currents and stress/strain tolerances of these wires were analyzed. Low reduction of critical current (⩽10%) by twisting between 50 mm and 12.5 mm was observed, especially for the wire with 54 filaments, which also showed the best strain tolerance to tension, ∼0.43% at 4.2 K. The engineering current density of the 18-filament wire was decreased by 56% by drawing from 0.83 mm to 0.4 mm, but improved by ∼24% by rolling from 0.83 mm to 0.64 mm. A small uninsulated coil was made from wire flattened from 0.83 mm to 0.64 mm by the wind and react process, resulting in a very high winding packing factor of 0.91 and also a high winding current density of 104 A cm−2 at B ⩽ 5.6 T. The presented properties are interesting for possible applications of these MgB2 wires in DC windings.

The maximum extent of the filaments and sheets in the cosmic web: an analysis of the SDSS DR17

ABSTRACT Filaments and sheets are striking visual patterns in cosmic web. The maximum extent of these large-scale structures are difficult to determine due to their structural variety and complexity. We construct a volume-limited sample of galaxies in a cubic region from the SDSS, divide it into smaller subcubes and shuffle them around. We quantify the average filamentarity and planarity in the 3D galaxy distribution as a function of the density threshold and compare them with those from the shuffled realizations of the original data. The analysis is repeated for different shuffling lengths by varying the size of the subcubes. The average filamentarity and planarity in the shuffled data show a significant reduction when the shuffling scales are smaller than the maximum size of the genuine filaments and sheets. We observe a statistically significant reduction in these statistical measures even at a shuffling scale of $\sim 130 \, {{\, \rm Mpc}}$, indicating that the filaments and sheets in three dimensions can extend up to this length scale. They may extend to somewhat larger length scales that are missed by our analysis due to the limited size of the SDSS data cube. We expect to determine these length scales by applying this method to deeper and larger surveys in future.

Optimizing intraluminal monofilament model of ischemic stroke in middle-aged Sprague–Dawley rats

Intraluminal monofilament model of middle cerebral artery occlusion (MCAO) is widely adopted for ischemic stroke; and Sprague-Dawley (SD) rats are commonly used rodents for preclinical research. Due to the paucity of information on the appropriate monofilament size for inducing MCAO in SD rats and the importance of including middle-aged models in ischemic stroke studies, we aimed to: (i). determine an appropriate Doccol® monofilament size for middle-aged male SD rats which weighed > 500g following 24-h transient MCAO survival as well as (ii). demonstrate the optimal Doccol® filament size for middle-aged males (≤ 500g) and females (273-300g) while using young adult male SD rats (372-472g) as control for severity of infarct volume following 7-days post-MCAO. All rats were subjected to 90-min transient MCAO. We show that 0.43mm Doccol® monofilament size is more appropriate to induce large infarct lesion and optimal functional deficit when compared to 0.45mm and 0.47mm at 24h post-MCAO. Our data on infarct volumes at 7days post-MCAO as well as the observed weight loss and functional deficits at post-MCAO days 1, 3 and 7 demonstrate that 0.41mm, 0.37mm and 0.39mm are optimal Doccol® filament sizes for middle-aged male (477.3 ± 39.61g) and female (302.6 ± 26.28g) as well as young-adult male (362.2 ± 28.38g) SD rats, respectively.

Optimization of 3D Printing Technology for Fabrication of Dental Crown Prototype Using Plastic Powder and Zirconia Materials.

This research was aimed at developing a dental prototype from 3D printing technology using a synthetic filament of polylactic acid (PLA) and zirconium dioxide (ZrO2) with glycerol and silane coupling agent as a binder. A face-centered central composite design was used to study the effects of the filament extrusion parameters and the 3D printing parameters. Tensile and compressive testing was conducted to determine the stress-strain relationship of the filaments. The yield strength, elongation percentage and Young's modulus were also calculated. Results showed the melting temperature of 193 °C, ZrO2 ratio of 17 wt.% and 25 rpm screw speed contributed to the highest ultimate tensile strength of the synthetic filament. A Nozzle temperature of 210 °C and an infill density of 100% had the most effect on the ultimate compressive strength whilst the printing speed had no significant effects. Differential scanning calorimetry (DSC) was used to study the thermal properties and percentage of crystallinity of PLA filaments. The addition of glycerol and a silane coupling agent increased the tensile strength and filament size. The ZrO2 particles induced the crystallization of the PLA matrix. A higher crystallization was also obtained from the annealing treatment resulting in the greater thermal resistance performance of the dental crown prototype.

Influence of filament fabrication parameter on tensile strength and filament size of 3D printing PLA-3D850

Polylactic acid (PLA) is a popular and widely used thermoplastic material used in fused filament fabrication (FDM) due to its biodegradability and biocompatibility. This paper aims to study the effects of extrusion parameters on the tensile strength quality of the 3D printing filament. The research began by extruding a 3D850D grade PLA pellet from Ingeo, NatureWorks, USA into a single filament extruder machine with an extrusion temperature range from 165 °C to 185 °C and a screw rate of 2 rpm to 6 rpm. The dog bone design (ASTM D638) with a 90° raster angle of line pattern and 100 % infill density was used for the fabrication of 3D printed specimens. Taguchi method was implemented to design the experiment to achieve the optimized parameters, and lastly, a tensile test was conducted to analyse the strength quality of the extruded filament through the 3D printing process. The result of the current study shows that the optimum extrusion temperature and speed that achieve the highest tensile strength with a good filament size of PLA-3D850 is around 175 °C and 4 rpm respectively.

Enhanced Resistive Switching Performance through Air-Stable Cu2AgSbI6 Thin Films for Flexible and Multilevel Storage Application.

Herein, the lead-free halide perovskite films with different Cu-to-Ag ratios (Cu3-xAgxSbI6, x = 0, 1, 2, or 3) have been prepared by a spin-coating method at low temperature. The enhanced resistive switching (RS) performance of more uniform SET/RESET voltages and the endurance up to at least 1600 cycles are found in the RS memory with a device structure of Ag/PMMA/Cu2AgSbI6/ITO. The device performance is not degraded under different bending angles and after 103 bending cycles, which is beneficial for flexible memory applications. The appropriately increased activation energy of the perovskites with the partial substitution of Ag atoms, which would lead to a more robust filament formed, is proposed to explain the enhanced RS mechanism. Importantly, the effective size and number of filaments measured by conductive AFM are introduced to confirm the multilevel storage effect of Cu2AgSbI6. The multilevel storage characteristics with four resistance levels are demonstrated by various compliance currents. Moreover, the Cu2AgSbI6 memory devices still exhibit enhanced RS properties and multilevel storage after 75 days of exposure to ambient conditions. Our study provides a strategy for improving the stability and high-density storage applications of halide perovskite RS memory devices.

Electro-Chemo-Mechanical Failure of Solid Electrolytes Induced by Growth of Internal Lithium Filaments.

Growth of lithium (Li) filaments within solid electrolytes, leading to mechanical degradation of the electrolyte and even short circuit of the cell under high current density, is a great barrier to commercialization of solid-state Li-metal batteries. Understanding of this electro-chemo-mechanical phenomenon is hindered by the challenge of tracking local fields inside the solid electrolyte. Here, a multiphysics simulation aiming to investigate evolution of the mechanical failure of the solid electrolyte induced by the internal growth of Li is reported. Visualization of local stress, damage, and crack propagation within the solid electrolyte enables examination of factors dominating the degradation process, including the geometry, number, and size of Li filaments and voids in theelectrolyte. Relative damage induced by locally high stress is found to preferentially occur in the region of the electrolyte/Li interface having great fluctuations. A high number density of Li filaments or voids triggers integration of damage and crack networks by enhanced propagation. This model is built on coupling of mechanical and electrochemical processes for internal plating of Li, revealing evolution of multiphysical fields that can barely be captured by the state-of-the-art experimental techniques. Understanding mechanical degradation of solid electrolytes with the presence of Li filaments paves the way to design advanced solid electrolytes for future solid-state Li-metal batteries.

Ag-Ion-Based Transparent Threshold Switching Selector with Filament-Size-Dependent Rectifying Behavior.

A metal-insulator-metal-structured Ag-filament-based transparent threshold switch is developed as a selector device for a crossbar array, which can lead to high-density integration of advanced memory devices. Both threshold switching and rectifying behavior were achieved based on sensitive control of the filament size. Conduction mechanism analyses demonstrated that the rectifying behavior resulted from the Schottky barrier at the interface. From the threshold switching, including the rectifying behavior, the available crossbar array size is 105-times larger.

Osteoconductivity of bone substitutes with filament-based microarchitectures: Influence of directionality, filament dimension, and distance.

63Additive manufacturing can be applied to produce personalized bone substitutes. At present, the major three-dimensional (3D) printing methodology relies on filament extrusion. In bioprinting, the extruded filament consists mainly of hydrogels, in which growth factors and cells are embedded. In this study, we used a lithography-based 3D printing methodology to mimic filament-based microarchitectures by varying the filament dimension and the distance between the filaments. In the first set of scaffolds, all filaments were aligned toward bone ingrowth direction. In a second set of scaffolds, which were derived from the identical microarchitecture but tilted by 90°, only 50% of the filaments were in line with the bone ingrowth direction. Testing of all tricalcium phosphate-based constructs for osteoconduction and bone regeneration was performed in a rabbit calvarial defect model. The results revealed that if all filaments are in line with the direction of bone ingrowth, filament size and distance (0.40-1.25 mm) had no significant influence on defect bridging. However, with 50% of filaments aligned, osteoconductivity declined significantly with an increase in filament dimension and distance. Therefore, for filament-based 3D- or bio-printed bone substitutes, the distance between the filaments should be 0.40 to 0.50 mm irrespective of the direction of bone ingrowth or up to 0.83 mm if perfectly aligned to it.

In situ defect detection and feedback control with three-dimensional extrusion-based bioprinter-associated optical coherence tomography.

Extrusion-based three-dimensional (3D) bioprinting is one of the most common methods used for tissue fabrication and is the most widely used additive manufacturing technique in all industries. In extrusion-based bioprinting, printing defects related to material deposition errors lead to a significant deviation from shape to function between the printed construct and design model. Using 3D extrusion-based bioprinter-associated optical coherence tomography (3D P-OCT), an in situ defect detection and feedback system was presented based on the accurate defect analysis and location, and a pre-built feedback mechanism. Using 3D P-OCT, multi-parameter quantification of the material deposition was carried out in real time, including the filament size, layer thickness, and layer fidelity. The material deposition errors under different paths were quantified and located specifically, including the start-stop points, straight-line path, and turnarounds. The pre-built feedback mechanism involving the control inputs, such as printing path, pressure, and velocity, provided the basis for in situ defect detection and real-time feedback control. In particular, the second printing repair can be performed after the broken filament defect is detected and located. After printing, fidelity can be quantitatively analyzed based on the point cloud registration between the 3D P-OCT result and the design model. In conclusion, 3D P-OCT enables in situ defect detection and feedback control, broken filament repair, and 3D fidelity analysis to achieve high-fidelity printing from shape to function.

Abnormal Laryngopharyngeal Sensation in Adductor Laryngeal Dystonia Compared to Healthy Controls.

Laryngeal sensory abnormality has been implicated as a component of adductor laryngeal dystonia (AdLD). The study objective was to assess laryngopharyngeal sensation in AdLD utilizing a calibrated, tactile aesthesiometer to deliver differential stimuli to lateral pyriform sinus (LPS), aryepiglottic fold (AEF), and false vocal fold (FVF). Patients with known Botox-responsive AdLD underwent sensory testing using a previously-validated methodology involving calibrated tactile stimuli (6-0, 5-0, 4.5-0, 4-0 nylon monofilaments). Laryngeal adductor reflex (LAR) and participant-rated perceptual strength of stimulI were evaluated. Responses were compared to normative controls (n=33). Two-samples, Mann-Whitney and Fisher exact tests compared mean strength ratings and LAR between AdLD and control groups. Mixed-effects logistic regression and linear models assessed association of filament size, stimulus site, age, sex, and LD status on LAR and perceptual strength rating respectively. Thirteen AdLD patients (nine women, mean age 60+/-15 years) completed testing. Average LAR response rates were higher amongst all filament sizes in AdLD versus controls at LPS (56.3% vs. 35.7%) and AEF (96.1% vs. 70.2%) with comparable rates at FVF (90.2% vs. 91.7%). AdLD had 3.3 times the odds of observed LAR compared to controls (p=0.005), but differences in subjective detection of stimuli, perceptual strength ratings, and cough/gag rates were insignificant on multivariate modeling (p > 0.05). This is the first study to objectively assess laryngopharyngeal sensation in AdLD. Findings demonstrated increased laryngopharyngeal sensation in AdLD compared to controls. The identification of increased laryngeal hypersensitivity in these patients may improve understanding of AdLD pathophysiology and identify future targets for intervention. 2 Laryngoscope, 133:2271-2278, 2023.

Internal rotation of ELM filaments on NSTX

Edge localized modes (ELMs) are a threat to tokamaks due to their high heat and particle loads on plasma facing components. A significant portion of this energy is carried and deposited by the emerging ELM filaments, whose dynamics are directly connected to their impact. Therefore, understanding their underlying physics is important for the operation of future fusion reactors. Our paper extends our knowledge of ELM filaments by reporting on their internal rotation (spinning) around the magnetic field lines along which they are extended. Our analysis of gas-puff imaging data on National Spherical Torus Experiment shows that ELM filaments are characterized by internal rotation in the direction of the ion-gyromotion with ω=15.2 krad/s median angular velocity, which is approximately three times faster than the blob rotation in the background turbulence. The characteristic size of the ELM filament was also assessed and found to be similar to the blobs. A nearly linear trend was found between the angular velocity and the radial velocity of the ELM filament. The angular velocity was found to be linearly dependent on the distance of the filament from the separatrix, as well. An analytical model called the shear-induced rotation model was identified as a candidate for explaining the physics of the observations. Our results show that the modeled mechanism could significantly influence the rotation of the ELM filament; however, it cannot be a sole contributor.

Controllable parameters as the essential components in the analysis, manufacturing and design of 3D woven composites

The comprehensive design feasibility for woven composites has been established by identifying the missing component in the design tool for these materials, the so-called controllable parameters. These are the parameters that are involved, directly or indirectly, in manufacturing of woven preforms, and they include the tow densities, the number and the size of filaments in a tow and intra-tow fibre volume fractions. Controllable parameters have been related through a simple procedure to the conventional geometric parameters of woven composites, which eliminates the need for their costly, inefficient, and often unreliable measurements. The controllable parameters provide sufficient representation of woven geometry in terms of both modelling and manufacture, thus offering common terminology to the woven composite designers and manufacturers. This also allows to naturally involve the practical considerations and manufacturing restrictions in material design exercises. With controllable parameters being incorporated in woven composite design framework, a direct analogy can be drawn to classical lamination theory-based design for conventional laminates. The wide applicability of the design tool has been demonstrated via a series of systematic material characterisation exercises carried out with woven composites of sufficiently different internal architectures and constituents, which also showed good predictive capability of the models involved.

Preliminary Study of 4 T Superconducting Dipole for a Light Rotating Gantry for Ion-Therapy

A collaboration between CERN, CNAO, INFN, and MedAustron has been formed aiming at designing a light rotating gantry suitable for hadron therapy based on 430 MeV/n carbon ion beams. After a first design for a 3 T dipole field, as the backbone of the gantry magnetic system, now the collaboration is looking at an alternative design, for at least 4 T field with a faster ramp rate. The magnet is designed according to the cosθ layout to be wound with Nb-Ti superconducting Rutherford cable. One of the main challenges is the very small curvature radius of 1.65 m with a relatively large aperture, of 70-90 mm. Another challenge is the use of indirect cooling despite the cycling operation of 0.4 T/s. The paper reports the preliminary investigation for a 4.5 T dipole. The design will be followed by the construction of a 1 m long demonstrator to be manufactured and tested at INFN (LASA laboratory) in about three years. The conductor is a Rutherford cable of 2.6 µm Nb-Ti filament size, embedded in a Cu-Mn alloy matrix. The resulting gantry is very compact: the collaboration is working on integration between gantry structure and magnets to allow reducing the rotating weight in the range 50-80 tons, which is a factor 4 to 5 less than the present state-of-the-art.

Cross-field and parallel dynamics of SOL filaments in TCV

Using recently installed scrape-off layer diagnostics on the tokamak à configuration variable, we characterise the poloidal and parallel properties of turbulent filaments. We access both attached and detached divertor conditions across a wide range of core densities (f G ∈ [0.09, 0.66]) in diverted L-mode plasma configurations. With a gas puff imaging (GPI) diagnostic at the outer midplane we observed filaments with a monotonic increase in radial velocity (from 390 m s−1 to 800 m s−1) and cross-field radii (from 8.5 mm to 13.4 mm) with increasing core density. Interpreting the filament behaviour in the context of the two-region model by Myra et al (2006 Phys. Plasmas 13 112502), we find that they populate the ideal-interchange regime (C i) in discharges at very low densities, and the resistive X (RX)-point regime for all other discharges. The scaling of filament velocity versus size shows good agreement with this interpretation. These results are discussed and compared with previous probe-based measurements for similar conditions, which mostly placed filaments in TCV in the resistive ballooning (RB) regime (Tsui et al 2018 Phys. Plasmas 25 072506). In addition, for the first time in TCV, the parallel filament extension is studied by magnetically aligning the GPI measurements at the outboard midplane with a reciprocating probe in the divertor. In agreement with the filaments being in the ideal-interchange and the RX-point regimes, they are found to extend beyond the X-point into the outer divertor leg.