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Skeletal muscle is an important structure responsible for producing movement, storing nutrients, maintaining posture and providing stability across joints. Unlike smooth and cardiac muscle, control can be voluntary. This review article will outline the macroscopic and microscopic appearance of skeletal muscle, the method by which it contracts, the types of skeletal muscle and pathology associated with it. [ABSTRACT FROM AUTHOR]

Copyright of Saudi Art & Design Journal is the property of Saudi Art & Design Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new technique of additive prototyping filament volumetric nanostructuring based on the high-speed mechanical mixing of acrylonitrile-butadiene-styrene (ABS) copolymer granules and single-walled carbon nanotube (CNT) powder (without prior dispersion in solvents) is considered. The morphological spectra of scanning electron microscopy (SEM) images of nanostructured filament slice surfaces were obtained and characterized with the original mathematical simulation. The relations of structural changes in the "ingredient-matrix" polymer system with dielectric and mechanical properties of the ABS-based filaments were established. The supplementation of 1.5 mass.% of CNT powder to the ABS filament composition leads to the tensile strength increasing from 36 ± 2 to 42 ± 2 MPa. It is shown that the greater the average biharmonic amplitude and the morphological spectrum localization radius of the slice surfaces' SEM images, the lower the electrical resistance of the corresponding nanostructured filaments. The possibility of carbon nanotube-modified filament functional layers forming using the extrusion additive prototyping technique (FFF) on the surface of plasma-chemically modified PET substrates (for the creation of load cell elements) is experimentally demonstrated. [ABSTRACT FROM AUTHOR]

Filaments used in textile products have many design parameters such as length, diameter, tip shape, material properties, etc. In order to design and develop the products efficiently that satisfy the desired functions, it is important to estimate the mechanical properties of filaments with various design parameters and to quantify the effects of design parameters on the mechanical behavior. In this study, we focused on as one of the design parameters of textile products, and evaluated the effects of this parameter on the mechanical properties of filaments under the sliding behavior based on the numerical and experimental approach. The results had shown that the difference in the tip shape of filaments affects the load value applied to the contacting body. It was also shown that the difference in the tip shape affected the deformation behavior. The difference of the tip shape was caused by the strain energy density of filaments during sliding movement. We believed that the results obtained in this study would be useful for the design and development of textile products efficiently. [ABSTRACT FROM AUTHOR]

Based on data from the national waste information system, total waste in Indonesia in 2022 will be 36.1 million tons per year. Referring to this data, there is still a lack of waste processing and requires quite large costs for waste processing resulting from the increase in population, changes in consumption patterns and people's lifestyles. As a solution, researchers have developed a tool to make 3D printing filament using used bottles as the main material. The tool is equipped with a stepper motor that controls the process of winding plastic bottle tape into 3D printing filament. Regulating the rotation of the stepper motor and controlling the tool as a whole uses an Arduino UNO microcontroller and a potentiometer. Based on research results, on PET and PP bottles, speed control results were obtained for PET bottles using a speed of 49 rpm, the results obtained were good with a diameter of 1.75 mm. and for pp bottles it is at a speed of 26 rpm. For the PP type, good quality filament results were obtained with a diameter of 1.75 mm. in further research to use PID control so that PWM changes are more stable for motor rotation, use a power supply with a more stable output, and determine the right angle for cutting plastic bottles to produce the same cut. [ABSTRACT FROM AUTHOR]

The filament material extrusion (ME) process manufactures functional components for a wide range of personalized applications in medicine, fashion and remanufacturing cases, or customized batch production for aviation and automotive industries. Therefore, structural and welding parameters affect porosity during 3D printing and are of paramount interest concerning the parts' mechanical response to static and dynamic loadings. This work aims to arrange the literature's experimental findings of crucial processing parameters' effects on the fused filament fabrication (FFF) part's porosity and structural strength. Therefore, the materials and structure parameters, including the filament material properties, deposited strand geometry, infill rate, infill pattern design type and orientation, and part orientation, as well as welding parameters such as material flow, nozzle temperature, bed temperature, printing feed, and environmental conditions, are critically reviewed and study in profoundness regarding porosity and mechanical loading of 3D printed parts. Experimental studies are critically examined, emphasizing the effects of parameters and interactions between them. [ABSTRACT FROM AUTHOR]

The efficacy of current treatments is still insufficient for Alzheimer's disease (AD), the most common cause of Dementia. Out of the two pathological hallmarks of AD amyloid-ß plaques and neurofibrillary tangles, comprising of tau protein, tau pathology strongly correlates with the symptoms of AD. Previously, screening for inhibitors of tau aggregation that target recombinant tau aggregates have been attempted. Since a recent cryo-EM analysis revealed distinct differences in the folding patterns of heparin-induced recombinant tau filaments and AD tau filaments, this study focused on AD seed-dependent tau aggregation in drug repositioning for AD. We screened 763 compounds from an FDA-approved drug library using an AD seed-induced tau aggregation in SH-SY5Y cell-based assay. In the first screening, 180 compounds were selected, 72 of which were excluded based on the results of lactate dehydrogenase assay. In the third screening with evaluations of soluble and insoluble tau, 38 compounds were selected. In the fourth screening with 3 different AD seeds, 4 compounds, lansoprazole, calcipotriene, desogestrel, and pentamidine isethionate, were selected. After AD seed-induced real-time quaking-induced conversion, lansoprazole was selected as the most suitable drug for repositioning. The intranasal administration of lansoprazole for 4 months to AD seed-injected mice improved locomotor activity and reduced both the amount of insoluble tau and the extent of phosphorylated tau-positive areas. Alanine replacement of the predicted binding site to an AD filament indicated the involvement of Q351, H362, and K369 in lansoprazole and C-shaped tau filaments. These results suggest the potential of lansoprazole as a candidate for drug repositioning to an inhibitor of tau aggregate formation in AD. [ABSTRACT FROM AUTHOR]

Neuroepithelial cells (NECs) within the fish gill contain the monoamine neurochemical serotonin (5-HT), sense changes in the partial pressure of oxygen (PO2) in the surrounding water and blood, and initiate the cardiovascular and ventilatory responses to hypoxia. The distribution of neuroepithelial cells (NECs) within the gill is known for some fish species but not for the Gulf toadfish, Opsanus beta, a fish that has always been considered hypoxia tolerant. Furthermore, whether NEC size, number, or distribution changes after chronic exposure to hypoxia, has never been tested. We hypothesize that toadfish NECs will respond to hypoxia with an increase in NEC size, number, and a change in distribution. Juvenile toadfish (N = 24) were exposed to either normoxia (21.4 ± 0.0 kPa), mild hypoxia (10.2 ± 0.3 kPa), or severe hypoxia (3.1 ± 0.2 kPa) for 7 days and NEC size, number, and distribution for each O2 regime were measured. Under normoxic conditions, juvenile toadfish have similar NEC size, number, and distribution as other fish species with NECs along their filaments but not throughout the lamellae. The distribution of NECs did not change with hypoxia exposure. Mild hypoxia exposure had no effect on NEC size or number, but fish exposed to severe hypoxia had a higher NEC density (# per mm filament) compared to mild hypoxia-exposed fish. Fish exposed to severe hypoxia also had longer gill filament lengths that could not be explained by body weight. These results point to signs of phenotypic plasticity in these juvenile, lab-bred fish with no previous exposure to hypoxia and a strategy to deal with hypoxia exposure that differs in toadfish compared to other fish. [ABSTRACT FROM AUTHOR]

Fused deposition or fused layer additive manufacturing is a technique in which a part is fabricated layer by layer using filament or pellets-form input material. The extruder is the central part of the fused deposition additive manufacturing (FDAM) system. The extrusion mechanism is unique to the geometry and form of the feedstock material. Extrusion of filament-form material through the nozzle needs to design of a material feeding mechanism based on various filament extrusion parameters. At the same time if the material is in the form of pellets, then the design of the feeding mechanism is very different due to the shape and size of the pellets. These two different design strategies for material extrusion namely the design of the feeding mechanism of filament and pellets form materials have been a major concern to avoid unwanted deformation of extruded materials in FDAM. These two design strategies for filament and pellet-form materials have led to the development of several material extrusion strategies. The present paper reviews various material extrusion strategies developed for FDAM of filament or pellets form input material. This article presents the review of design, development, performance evaluation, and process planning for each extrusion strategy. Based on the literature review authors have suggested a possible extrusion method that can accept both forms of materials to fulfill the need for the filament as well as pellets-based additive manufacturing. [ABSTRACT FROM AUTHOR]

3D printing is one of the plastic recycling processes that deliver a mechanically sustainable product and may be used for 4D printing applications, such as self-assembly, sensors, actuators, and other engineering applications. The success and implementation of 4D printing are dependent on the tendency of the shape memory with the action of external stimuli, such as heat, force, fields, light, and pH. Acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) are the most common materials for fused filament fabrication-based 3D printing processes. However, the low-shaped memory tendency on heating and weaker and less rigidity of ABS limit the application domains. PLA is an excellent responsive behavior when the action of heat has high stiffness. The incorporation of PLA into ABS is one of the solutions to tune the shape memory effect for better applicability in the 4D printing domain. In this study, the primary recycled PLA was incorporated into the primary recycled ABS matrix from 5 to 40% (weight%), and composites were made by extrusion in the form of cylindrical filaments for 4D printing. The tensile and shape memory properties of the recycled ABS–PLA composites were investigated to select the best combination. The results of the study were supported by fracture analysis by shape memory analysis, scanning electron microscopy, and optical microscopy. This study revealed that the prepared ABS–PLA-based composites have the potential to be applied in self-assembly applications.

ABSTRACT Candida auris, an emerging multidrug-resistant fungal pathogen, predominately colonizes the human skin long term leading to subsequent life-threatening invasive infections. Fungal morphology is believed to play a critical role in modulating mucocutaneous antifungal immunity. In this study, we used an intradermal mouse model of C. auris infection to examine fungal colonization and the associated innate and adaptive immune response to yeast and filamentous C. auris strains. Our results indicate that mice infected with a filamentous C. auris had significantly decreased fungal load compared to mice infected with the yeast form. Mice infected with yeast and filamentous forms of C. auris stimulated distinct innate immune responses. Phagocytic cells (CD11b+Ly6G+ neutrophils, CD11b+Ly6Chi inflammatory monocytes, and CD11b+MHCII+CD64+ macrophages) were differentially recruited to mouse skin tissue infected with yeast and filamentous C. auris. The percentage and absolute number of interleukin 17 (IL-17) producing innate lymphoid cells, TCRγδ+, and CD4+ T cells in the skin tissue of mice infected with filamentous C. auris were significantly increased compared to the wild-type of yeast strain. Furthermore, complementation of filamentous mutant strain of C. auris (Δelm1 + ELM1) strain exhibited wild-type yeast morphology in vivo and induced comparable level of skin immune responses similar to mice infected with yeast strain. Collectively, our findings indicate that yeast and filamentous C. auris induce distinct local immune responses in the skin. The decreased fungal load observed in mouse skin infected with filamentous C. auris is associated with a potent IL-17 immune response induced by this morphotype.IMPORTANCECandida auris is a globally emerging fungal pathogen that transmits among individuals in hospitals and nursing home residents. Unlike other Candida species, C. auris predominantly colonizes and persists in skin tissue resulting in outbreaks of systemic infections. Understanding the factors that regulate C. auris skin colonization and host immune response is critical to develop novel preventive and therapeutic approaches against this emerging pathogen. We identified that yeast and filamentous forms of C. auris induce distinct skin immune responses in the skin. These findings may help explain the differential colonization and persistence of C. auris morphotypes in skin tissue. Understanding the skin immune responses induced by yeast and filamentous C. auris is important to develop novel vaccine strategies to combat this emerging fungal pathogen.

The preparation and characterization of filaments from janeng have been studied. The janeng filament (PCl-JS) process starts with the preparation and gelatinization of janeng starch, and then the resulting starch gelatinization, which is usually called thermoplastically processable starch (TPS) is carried out by filament processing by mixing PCl-g-GMA and JS at a temperature of 170 °C and 80 rpm for 15 min. The prepared filaments were analyzed. SEM studies show that the fracture surface of PCl-JS0 filaments provides a uniform fiber dispersion, in contrast to the morphology showing large and interconnected starch domains as the starch concentration increases from 1% to 9%. The intensity of hydrogen bonds observed in the spectrum via FTIR increased in band as the concentration of JS increased. XRD analysis observed that the crystallinity and crystal size of filaments without starch were higher than those of other PCl filaments that had undergone modification with starch. Mechanical analysis showed that starch did not have a negative effect on the tensile strength of the filaments, indicating good compatibility between JS and the PCl matrix. When the additional concentration of JS increased to 9%, the strength of PCl-JS filaments increased to 37 MPa, which was caused by the higher crystallinity induced by starch. The glass temperature of the filament sample was observed using DSC, which showed that PCl without JS occurred at 48.2 °C and shifted (+2 °C) towards 49.4 °C when JS was added. For all DSC curves, the exothermic peak was observed around 56–59 °C. The melt flow behavior of PCl-JS filaments decrease with increasing starch content.

In recent years, metal chip powders obtained from solid-state processes have shown great potential as a sustainable raw material for powder technologies. The material and fragmentation process of the chips has a significant role in the final characteristics of the powder particles, such as size and particle size distribution, shape, surface, and structure, which are essential parameters to consider when converting chips to powder for applications. However, tool steel chips as a powder raw material have not yet been significantly studied. In this study, the steel chips were from machining AISI H13 steel and the milling process used a ball mill, and the challenge was to obtain powder particle sizes of around 20 µm with suitable properties from the application of envisaged material extrusion (MEX). A comparison study with the commercial raw material for MEX, such as powder metal filament extrusion, was performed. This study highlights the behaviors of chip powders during all steps of MEX, namely, feedstock and filament production, 3D object shaping, thermal de-binding, and sintering. A comparison of the mixture based on powder from chips and commercial powders for MEX was performed after evaluating the mixing torque of the powder and the system of binders and additives suitable for the rheological characteristics required for an extrusion mixture, and optimizing the binder removal and the sintering conditions. The 3D objects resulting from chip powders had a refined microstructure, showing an increase of 15% in the microhardness when compared with the those resulting from commercial powders.

Lignocellulosic waste materials are among the most abundant raw materials on Earth, and they have been widely studied as natural additives in materials, especially for polymer composites, with interesting results when it comes to improving physiochemical properties. The main components of these materials are cellulose, hemicellulose, and lignin, as well as small amounts of other polysaccharides, proteins, and other extractives. Several kinds of lignocellulosic materials, mainly fibers, have been evaluated in polymer matrices, and recently, the use of particles has increased due to their high surface area. Garlic is a spice seed that generates a waste husk that does not have applications, and there are no reports of industrial use of this kind of lignocellulosic material. Additive manufacturing, also known as 3D printing, is a polymer processing technique that allows for obtaining complex shapes that are hard to obtain with ordinary techniques. The use of composites based on synthetic polymers and lignocellulosic materials is a growing field of research. In the present work, the elaboration and evaluation of 3D-printed polypropylene–garlic husk particle (PP-GHP) composites are reported. First, the process of obtaining a filament by means of a single extrusion was carried out, using different GHP contents in the composites. Once the filament was obtained, it was taken to a 3D printer to obtain probes that were characterized using differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) was performed with the aim of evaluating the thermal behavior of the 3D-printed PP-GHP composites. According to the obtained results, the crystallization process and thermal stability of the PP-GHP composites were modified with the presence of GHP compared with pristine PP. Dynamic mechanical analysis (DMA) showed that the addition of GHP decreased the storage modulus of the printed composites and that the Tan δ peak width increased, which was associated with an increase in toughness and a more complex structure of the 3D-printed composites. X-ray diffraction (XRD) showed that the addition of GHP favored the presence of the β-phase of PP in the printed composites.

In this work, we study the characteristics of femtosecond-filament-laser-matter interactions and laser-induced periodic surface structures (LIPSS) at a beam-propagation distance up to 55 m. The quantification of the periodicity of filament-induced self-organized surface structures was accomplished by SEM and AFM measurements combined with the use of discrete two-dimensional fast Fourier transform (2D-FFT) analysis, at different filament propagation distances. The results show that the size of the nano-scale surface features increased with ongoing laser filament processing and, further, periodic ripples started to form in the ablation-spot center after irradiation with five spatially overlapping pulses. The effective number of irradiating filament pulses per spot area affected the developing surface texture, with the period of the low spatial frequency LIPSS reducing notably at a high pulse number. The high regularity of the filament-induced ripples was verified by the demonstration of the angle-of-incidence-dependent diffraction of sunlight. This work underlines the potential of long-range femtosecond filamentation for energy delivery at remote distances, with suppressed diffraction and long depth focus, which can be used in biomimetic laser surface engineering and remote-sensing applications.

Backround. Polymer products produced by 3D printing are inferior in strength characteristics to cast parts. To increase the strength characteristics, impact strength and heat resistance of products, a composite filament was created, and a technology for its production and use was developed. The purpose of the study is to develop technological regimes for the production and use of composite filament, to evaluate the mechanical properties of products obtained through layer-by-layer synthesis from the proposed composite material based on polyetheretherketone. Results. Equipment for the production of composite raw materials for 3D printing has been developed and the influence of technological modes on the quality of the resulting product has been studied. The results of assessing the mechanical properties of prototypes obtained by 3D printing from composite raw materials are presented.

The temperatures of the phase transitions for polyethyleneterephthalate samples containing recycled PET (the product Vivilen) and the waste materials from its production were analyzed by differential scanning calorimetry and x-ray structural analysis, and the ratio of the crystalline and amorphous phases was determined. The polyethyleneterephthalate samples were arranged according to their glass transition and melting points, which made it possible to correlate the samples according to the degree of crystallinity. In order to obtain a filament based on the dust waste from the solid-phase polycondensation process an extrusion temperature regime was established, and samples of filaments for 3D printing that meet the requirements of GOST R 59100-2020 were obtained. [ABSTRACT FROM AUTHOR]

On the basis of the characteristics of low-density polyethylene determined experimentally from the geometric dimensions of the extruder parts and COMSOL MULTIPHYSICS software a digital model of the apparatus was created, and the flow rate of the polymer melt from the extruder nozzle was calculated hydrodynamically. The agreement between the experimentally measured polymer flow rate and the value obtained from the model lies within the permissible error. This establishes the adequacy of the digital twin model, which will be used to predict the viscosity characteristics of composite materials based on low-density polyethylene and the technological regimes of their production by blending in the extruder. [ABSTRACT FROM AUTHOR]

Copyright of Farmacja Polska is the property of Polish Pharmaceutical Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of fibers from polylactic acid (PLA) to create nonwoven materials and threads is relevant. A study of the microstructure and properties of PLA threads was carried out, followed by comparison with polyamide ones. It has been established that PLA threads are bundles of monofilaments with a diameter of 14 ± 1 μm made of PLA with a high degree of crystallinity (up to 60%), which determines high tensile strength (90–95 MPa). PLA threads are characterized by shrinking up to 8% when heated above the glass transition temperature. [ABSTRACT FROM AUTHOR]

The development of a surface barrier discharge driven by a negative steplike voltage pulse with an amplitude of V = –8 kV in air at the atmospheric pressure and a pulse with an amplitude of V = –15 kV in nitrogen at a pressure of 6 atm is simulated numerically. Calculations for V = –8 kV were carried out using the local-electric-field and the local-electron-energy approximations. It is demonstrated that both approximations yield similar results on the dynamics of discharge development as a whole, the cathode-layer structure, and the field distribution at the front of the discharge. Substantial differences are observed in parameters of the discharge layer adjacent to the dielectric surface, which allowed to simulate an effect similar to filamentation of the discharge in nitrogen at a pressure of 6 atm and voltage of V = –15 kV in the local-energy approximation. [ABSTRACT FROM AUTHOR]

This paper presents the development and characterization of cost-effective short Kevlar fiber reinforced nylon composite filaments. The effect of Kevlar fiber content on the tensile properties and the fiber distribution morphology was explored. A small amount of short Kevlar fiber was twin-screw compounded with nylon to study the reinforcing effects. Optical microscopy was used to investigate the morphology and the fiber distribution in the nylon matrix. The tensile strength of Kevlar composites increased to 90 MPa and 99 MPa at the fiber content of 1 wt% and 3 wt%, respectively, compared with the tensile strength of 84 MPa for pure nylon. As the fiber content increased from 0 to 3 wt%, the tensile modulus increased from 3.28 to 3.77 GPa. The optical microscopy and SEM images indicate that the twin-screw compounder with a proper screw configuration could disperse and distribute the Kevlar fibers uniformly in the nylon matrix. Statistically, this study demonstrates that the tensile strength and tensile modulus of nylon filament can be effectively enhanced with the addition of small amount of Kevlar fiber (i.e., less than 3 wt%), without sacrificing the ductility. [ABSTRACT FROM AUTHOR]

Femtosecond lasers have been applied in the machining of zirconia ( ZrO 2 ) ceramics because of their ultrashort pulse duration and high peak power. However, the high-precision micromachining of zirconia remains challenging owing to an unclear understanding of the ultrafast laser–material interaction mechanisms. In this study, the transient processing phenomenon induced by a femtosecond laser pulse, namely electron excitation (filament), occurring on a picosecond to nanosecond timescale, was directly observed and quantitatively investigated inside ZrO 2 . A pump-probe imaging method comprising a focusing probe beam integrated with a high-speed camera was used. The evolution process, type variation, and related interaction mechanisms of the filament were revealed under different parameters, including laser pulse energy, sample position, and pulse duration. Finally, the generation mechanism of multiple filaments was clarified and successfully elucidated. This study reveals the ultrafast laser–material interaction mechanisms and the high-precision processing in the laser drilling of zirconia ceramics. [ABSTRACT FROM AUTHOR]

In view of the problem that the heat setting technology of Lyocell filament was not clear, Lyocell washed filaments were prepared by dry-jet wet spinning technology and the effects of heat setting tension, temperature and time on the mechanical properties and dimensional stability were investigated. The crystal, orientation and micropore structure of Lyocell filaments were analyzed by means of wide angle X-ray diffraction, small angle X-ray scattering and birefringence, and the relationship between structure and properties under heat setting was clarified. The results show that the moisture in the filaments can be removed when the washed filaments are heat-set at 100-130 °C for 3 min. During the heat setting process, the crystal structure of the filament changes little while the decrease of micropore size and the shrinkage of chain segments improve the densification and decrease the orientation degree. The mechanical properties cannot be weakened at the tension of 0.5-2.3 cN/dtex and the thermal shrinkage is lower than 0.7%. The heat setting with tension inhibits the disorientation of the cellulose segments effectively and keeps high crystallinity and high orientation of Lyocell filament, which guarantee both mechanical properties and dimensional stability of Lyocell filament. [ABSTRACT FROM AUTHOR]

Environmental concerns within the 3D printing industry have attracted interest in processing biodegradable, eco-friendly materials. Cellulose is the most abundant natural polymer on the planet. Cellulosic pulp, derived from biomass, can be dissolved in eco-friendly solvents such as N-methyl morpholine N-oxide (NMMO) to produce lyocell. Lyocell has had applications in the textile industry for the last decade. It has shown promise in producing high-quality cellulosic fibers and the ability to be altered, tailored, and manufactured with ease. Despite this, additive manufacturing using cellulose is still an area of research with ample room to grow. In this work, we propose an in-depth study of using lyocell to manufacture 3D-printed parts using an affordable desktop 3D-printer modification. The 3D printing process of lyocell is completely circular as the solvent can be recovered from 3D-printed parts. The design of the developed 3D printing equipment, the rheological properties, and the 3D printing of the cellulose-NMMO solution are discussed in this work. Extrudate swell, filament distortion and NMMO diffusion in the regeneration process were key experimental factors to control interlayer adhesion and 3D print quality. [ABSTRACT FROM AUTHOR]

The applicability of the previously proposed mechanism of filamentation of a surface barrier discharge in nitrogen by a nanosecond voltage pulse of positive polarity to the description of a similar process in nitrogen and air in the case of a pulse of negative polarity is studied numerically. The calculation results show that in this case, in nitrogen and air, there are also signs of the successful simulation of the filamentation effect, but at the same time, the overall dynamics of the discharge development differs qualitatively from that observed in the experiment. It is assumed that the origin of the unsuccessful simulation is the roughness of the local field approximation used in regions with sharp electron density gradients inherent to the filamentation zone. [ABSTRACT FROM AUTHOR]

Lilies are important cut and pot flowers locally and globally; however, qualified planting materials from in vitro culture are still limited. The culture generally uses scales and leaves, while filaments and ovules are rarely utilized. Filaments and ovules of EXO CF/E, RDF CG/E, and DZ CG/E genotypes of Lilium sp. were explored for their potential to establish in vitro propagation protocol using different Chu N6 medium and their modifications. The 9.9 shoots/explant from 1.5 regenerative explants/replication of RDF CG/E filaments was proven on Chu N6 medium containing 6.79 µM 2,4-dichlorophenoxyacetic acid (2,4-D), 2.27 µM thidiazuron (TDZ), and 90 g L-1 sucrose; 3.3 regenerative explants/replication and 8.4 shoots/explant of EXO CF/E ovules were determined on Chu N6 medium with 2.26 µM 2,4-D, 6.81 µM TDZ and 90 g L-1 sucrose; and slightly improved on Chu N6 macro elements, full vitamins of MS basal medium with 3.39 µM 2,4-D, 3.41 µM TDZ, 150 ml L-1 coconut water (CW) and 60 g L-1 sucrose. The shoots were proliferated on the established media. The shoots of EXO CF/E, RDF CG/E and DZ CG/E genotypes produced varied leaves/shoot, leaf length, leaf width, roots/shoot, root length and bulb diameter on Chu N6 medium hormone free with 1.5% AC, followed by hardening them in a glass house for one month. The hardened-plantlets were acclimatized in plastic pots containing charcoal husk and bamboo compost (1:1) with 39.8-63.6% survivability. The protocol has the potential to be applied to other genotypes or lilies by specific improvements at the acclimatization stage. [ABSTRACT FROM AUTHOR]

Additive manufacturing is an advanced manufacturing technology to produce components with superior quality, aesthetic shape, less wastage and reduced production time. Fused deposition modeling (FDM) is one of the additive manufacturing techniques adopted by small scale industries as it is most economical and produces compact sized components. Even though, the lack of feedstock (i.e., filament) material leads to increase in overall manufacturing cost. This paper explores design and fabrication of internal mixer (IM) and filament extruder for blending of composite materials, production of polymer filaments and hybrid composite filaments (i.e., polymer filaments with reinforcement of natural fibers) for FDM applications. The polylactic acid polymer, bamboo natural fibers and maleic anhydride compatibilizer are taken as a raw material. The internal mixer has been fabricated successfully is the most economical approach as compared to commercially available IM. The result shows that, the developed IM produces 250 g of blended mixture (i.e., combination of polymers, natural fibers and plasticizers) in a duration of 30 min. Also, the designed and fabricated portable filament extruder tested and extracted continuous polymer and hybrid filaments with a diameter ranging from 1.6 to 2 mm and mass flow rate of 15.6 mm3/s respectively. In addition, the obtained filament having no warping, without clogging, no under and over extrusion, more precise and most economical as compared to existing filament extruders. The developed IM and filament extruder are adequate to small scale vendors and industries. [ABSTRACT FROM AUTHOR]

Desminopathy is the most common intermediate filament disease in humans. The most frequent mutation causing desminopathy in patients is a R350P DES missense mutation. We have developed a rat model with an analogous mutation in R349P Des. To investigate the role of R349P Des in mechanical loading, we stimulated the sciatic nerve of wild-type littermates (WT) (n = 6) and animals carrying the mutation (MUT) (n = 6) causing a lengthening contraction of the dorsi flexor muscles. MUT animals showed signs of ongoing regeneration at baseline as indicated by a higher number of central nuclei (genotype: P

The atomic structure of the complete myosin tail within thick filaments isolated from Lethocerus indicus flight muscle is described and compared to crystal structures of recombinant, human cardiac myosin tail segments. Overall, the agreement is good with three exceptions: the proximal S2, in which the filament has heads attached but the crystal structure doesn't, and skip regions 2 and 4. At the head-tail junction, the tail α-helices are asymmetrically structured encompassing well-defined unfolding of 12 residues for one myosin tail, ∼4 residues of the other, and different degrees of α-helix unwinding for both tail α-helices, thereby providing an atomic resolution description of coiled-coil "uncoiling" at the head-tail junction. Asymmetry is observed in the nonhelical C termini; one C-terminal segment is intercalated between ribbons of myosin tails, the other apparently terminating at Skip 4 of another myosin tail. Between skip residues, crystal and filament structures agree well. Skips 1 and 3 also agree well and show the expected α-helix unwinding and coiled-coil untwisting in response to skip residue insertion. Skips 2 and 4 are different. Skip 2 is accommodated in an unusual manner through an increase in α-helix radius and corresponding reduction in rise/residue. Skip 4 remains helical in one chain, with the other chain unfolded, apparently influenced by the acidic myosin C terminus. The atomic model may shed some light on thick filament mechanosensing and is a step in understanding the complex roles that thick filaments of all species undergo during muscle contraction.

The efficacy of current treatments is still insufficient for Alzheimer’s disease (AD), the most common cause of Dementia. Out of the two pathological hallmarks of AD amyloid-β plaques and neurofibrillary tangles, comprising of tau protein, tau pathology strongly correlates with the symptoms of AD. Previously, screening for inhibitors of tau aggregation that target recombinant tau aggregates have been attempted. Since a recent cryo-EM analysis revealed distinct differences in the folding patterns of heparin-induced recombinant tau filaments and AD tau filaments, this study focused on AD seed-dependent tau aggregation in drug repositioning for AD. We screened 763 compounds from an FDA-approved drug library using an AD seed-induced tau aggregation in SH-SY5Y cell-based assay. In the first screening, 180 compounds were selected, 72 of which were excluded based on the results of lactate dehydrogenase assay. In the third screening with evaluations of soluble and insoluble tau, 38 compounds were selected. In the fourth screening with 3 different AD seeds, 4 compounds, lansoprazole, calcipotriene, desogestrel, and pentamidine isethionate, were selected. After AD seed-induced real-time quaking-induced conversion, lansoprazole was selected as the most suitable drug for repositioning. The intranasal administration of lansoprazole for 4 months to AD seed-injected mice improved locomotor activity and reduced both the amount of insoluble tau and the extent of phosphorylated tau-positive areas. Alanine replacement of the predicted binding site to an AD filament indicated the involvement of Q351, H362, and K369 in lansoprazole and C-shaped tau filaments. These results suggest the potential of lansoprazole as a candidate for drug repositioning to an inhibitor of tau aggregate formation in AD.

Research has been conducted to analyze and characterize ten 3D printing materials as potential Radiological Phantoms of Lung Organs. Eight filaments of PLA, ABS, HIPS, Carbon, Nylon, TPU, PETG, and Wood were printed using an FDM type 3D printer, and two resins, PLA resin and Water washable resin, were printed using an SLA type 3D printer. The phantoms were printed with thickness variations of 3 mm, 6 mm, and 9 mm. 8 parameters were used to obtain the best material, namely material density, CT number, electron density (Ne), effective electron density (EDG), electron density per volume (EDV), effective atomic number (Zeff), material constituent elements, and elastic Modulus. Based on comparing the values of 8 parameters, the most potential to be used as phantom material for lung organs is PLA.

Theoretical studies on oceans and large lakes have shown that submesoscale instabilities in frontal zones tend to reduce horizontal density gradients and enhance vertical density gradients, thereby re-stratifying the Surface Mixed Layer (SML). Submesoscale filament dynamics are primarily studied using numerical models and remote sensing imagery. However, in large lakes, this concept remains without substantial field validation, mainly due to the difficulty in conducting the necessary high-resolution water column measurements. Using a procedure we recently developed to predict the time and location of mesoscale and submesoscale features generated by strong wind fields, this work presents direct field evidence demonstrating the role of submesoscale cold filaments in re-stratifying the SML under weakly stratified conditions in a large lake (Lake Geneva). The dynamics of the observed filaments were further investigated with a high-resolution three-dimensional (3D) numerical model and Lagrangian particle-tracking. The numerical model accurately captured the formation of these filaments. The enhancement of thermal stratification strength, N², reached O(10-5) s-2 in areas adjacent to cold filaments under atmospheric cooling and heating conditions. In the pelagic zone (offshore), strong vertical velocities of O(100 m d-1) were associated with secondary circulation that rapidly transports and accumulates passive particles in the thermocline and hypolimnion layers, as confirmed by Acoustic Doppler Current Profiler (ADCP) backscattering intensity data. The field observations indicate that under weak stratification, Dissolved Oxygen (DO) variability reaches 0.5 mg l-1 near cold filaments. This documentation of strong vertical motions associated with submesoscale filaments is expected to contribute to the understanding of the vertical exchange of heat, contaminants and oxygen between the atmosphere and the pelagic zone of large lakes, as well as in oceans where carrying out such field measurements is very challenging. [ABSTRACT FROM AUTHOR]

The expansion and low cost of additive manufacturing technologies have led to a revolution in the development of materials used by these technologies. There are several varieties of materials that can be used in additive manufacturing by fused deposition modeling (FDM). However, some of the properties of these materials are unknown or confusing. This article addresses the need to know the thermal conductivity in different filaments that this FDM technology uses, because there are multiple applications for these additive manufacturing products in the field of thermal insulation. For the study of thermal conductivity, the DTC-25 commercial conductivity measurement bench was used, where the tests were carried out on a set of seven different materials with 100% fabrication density—from base materials such as acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA), to materials with high mechanical and thermal resistance such as thermoplastic polyurethane (TPU), polyether ether ketone (PEEK), and high-performance polyetherimide thermoplastic (ULTEM), to materials with metal inclusions (aluminum 6061) that would later be subjected to thermal after-treatments. This study shows how the parts manufactured with aluminum inclusions have a higher thermal conductivity, at 0.40 ± 0.05 W/m·K, compared to other materials with high mechanical and thermal resistance, such as TPU, with a conductivity of 0.26 ± 0.05 W/m·K. [ABSTRACT FROM AUTHOR]

This study investigates the effects of thermal treatment and silver nanoparticles on the mechanical and thermal properties of additively manufactured wood/polylactic acid (PLA) specimens. The 5 and 10 wt% additions of the wood flour into the PLA matrix are done in the twin screw extruder. The test specimens are produced from the filaments with a diameter of 1.75 mm using 3D printer. The mechanical properties of the 3D‐printed wood/PLA specimens are affected by the wood flour content, thermal treatment of wood, and silver nanoparticles. The 3D‐printed neat PLA specimens have better mechanical properties than the wood flour‐filled PLA specimens. The bending strength of the specimens enhances with increasing wood flour content while the tensile strength decreases. The increases in the mechanical properties reveal that the thermal treatment of the wood improves the compatibility between wood and PLA matrix, which hereby improves the interfacial adhesion. The addition of the silver nanoparticles positively affects the mechanical properties and it is more compatible with thermally modified wood particles as compared to the untreated wood particles. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) printing has been used as a promising technology in biomedical sciences and engineering. However, there is a lack of ready-to-use feedstock for biomedical applications. In this work, a series of PLA biocomposite filled with calcium sulfate (CaS) particles up to a maximum content of 40 wt% has been prepared by solvent casting method and subsequently processed into filament form through the melt compounding method. The objective of this study was to investigate the processibility of composite filament with maximum ceramic content through fused filament fabrication (FFF) process to improve the mechanical, thermal and biological performance of virgin PLA for biomedical application. The composite filament was extruded at a temperature of 160 °C at a constant speed with an average diameter of 1.70 ± 08 mm, compatible with the 3D printer's feeding system. Morphological, thermal, mechanical, and crystallization analysis using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric (TGA) analysis was performed on the extruded filament to evaluate the effect of ceramic content in the polymeric matrix. The thermal stability was improved upon addition of CaS particles into the PLA matrix. Subsequently, PLA-CaS solid specimen was 3D-printed and characterized for its mechanical, and geometrical accuracy. The maximum compressive strength obtained is 115 MPa for 20% ceramic loading, which then decreases with increased ceramic content. The biocompatibility test using MC3T3E1 cells confirmed zero cytotoxicity and cell grows well on all PLA and composite specimen. The results revealed that the composite biomaterials could be easily printed even at high ceramic loading and maintain their structural integrity and stability during the additive manufacturing process. These composites could be potential candidates for various biomedical applications, such as bone scaffolds and bioresorbable screws for Anterior Cruciate Ligament (ACL) reconstruction. [Display omitted] [ABSTRACT FROM AUTHOR]

Based on the results of mathematical modeling and theoretical research works, it was established that the most influential factors of 3D printing, affecting the quality and time of end products formation, are extruder die temperature, layers height, speed of printing head movement when forming products, as well as simultaneous fabrication of several products within one cycle. In the work, the modes of the FDM 3D printing process were worked out and the regularities of the influence of the mentioned parameters on the structure and properties of resulted 3D polylactide products were established. The parameters of product formation were experimentally determined, which provide the production of 3D objects with predicted properties: maximum strength (98 % of filament strength), high aesthetic quality (surface smoothness and resolution) and products with minimal investments of time during their production. [ABSTRACT FROM AUTHOR]

The summary of the article "Current State of Extrusion Processes in Dental Technology" describes the increasing importance of additive manufacturing in dental technology. The article provides an overview of the extrusion process, its applications, manufacturers, and various studies. It also presents future application possibilities. The most well-known extrusion process is the Fused Filament Fabrication (FFF) process, in which a thermoplastic polymer is melted and deposited on a build platform. Other materials such as ceramic or biological materials are also used. Various applications and indications for filament devices in dentistry are discussed. The article describes various materials and manufacturers used in additive manufacturing in dentistry. Various applications such as models, impression trays, complete dentures, facebow connectors, and inlays are mentioned. It emphasizes that multimaterial printing offers many possibilities but also brings challenges. Compared to other additive processes, extrusion processes are still imprecise but more environmentally friendly. The interest in additive technologies in education is also mentioned. The present bibliography includes various scientific articles and studies on the topic of 3D printing in dentistry. The articles cover various aspects such as the production of sports mouthguards, dental prosthetics, temporaries, and implant guide templates using 3D printing technology. Various materials and processes are examined, including polyamides, polyphenylsulfone, polylactic acid, and lithium disilicate. The articles provide information on the accuracy, mechanical properties, and aesthetic quality of the printed products. The authors conclude that 3D printing in dentistry offers promising opportunities to develop more efficient and precise solutions. [Extracted from the article]

The successful integration of hot-melt extrusion (HME) and fused deposition modelling (FDM) depends on a better understanding of the impact of environmental conditions on the printability of formulations, since they significantly affect the properties of the raw materials, whose control is crucial to enable three-dimensional printing (3DP). Hence, the objective of this work was to investigate the correlation between the environmental settings and the properties of paroxetine (PRX)-loaded filaments, previously produced by HME, which affect printability by FDM. The influence of different drying methods of the physical mixtures (PMs) and HME-filaments (FILs) on the quality and printability of these products was also assessed. The printability of FILs was evaluated in terms of the water content, and the mechanical and thermal properties of the products. Stability studies and physicochemical, thermal, and in vitro dissolution tests were carried out on the 3D-printed tablets. Stability studies demonstrated the high ductility of the PRX loaded FILs, especially under high humidity conditions. Under low humidity storage conditions (11% RH), the FILs became stiffer and were successfully used to feed the FDM printer. Water removal was slow when carried out passively in a controlled atmosphere (desiccator) or accelerated by using active drying methods (heat or microwave). Pre-drying of the PRX/excipients and/or PMs did not show any positive effect on the printability of the FIL. On the contrary, dry heat and, preferably, microwave mediated drying processes were shown to reduce the holding time required for successful FDM printing, enabling on-demand production at the point of care. [ABSTRACT FROM AUTHOR]

A linear stability analysis is carried out for viscoelastic filaments (formed by an unentangled polymer solution) during capillary thinning in the regime of unfolded polymer coils taking into account the relative motion of the solvent and the polymer. The conditions for the onset of filament instability with respect to axisymmetric modulation of its surface are found. The analysis is valid for relatively fast processes occurring at times shorter than the characteristic thinning time. It is shown that the growth rate of such pearling instability is determined by the osmotic modulus of the solution and the degree of orientation of macromolecules. In the case of nonassociative polymers, the instability develops (with the growth rate exceeding the rate of filament thinning) when the longitudinal length of stretched polymer chains exceeds the diameter of the filament. The theory is also applicable to soft gels and associative polymer solutions with very long relaxation times. The predictions of the theory are in agreement with experimental data. [ABSTRACT FROM AUTHOR]