Arrangement Of Fibers Research Articles

Simulation of fiber arrangement based on the properties of sliver irregularity

The study of fiber arrangement in a sliver is of great significance for predicting yarn quality, optimizing spinning processes, and promoting innovations in spinning technology. At present, most fiber arrangement models are based on the ideal sliver, which is not connected with the irregularity characteristics of the actual sliver, so that the simulated sliver is very different from the actual sliver. In this study, a simple, universal, and more accurate fiber arrangement model is proposed. In the simulation, the irregular arrangement of the left ends of the fibers is further considered; this is related to the total irregularity and structural irregularity of the actual sliver. In addition, the accuracy of the simulated sliver was evaluated using various indexes, including total irregularity, sliver structure irregularity, and sliver linear density fluctuation range. The results show that the fiber arrangement model proposed in this paper is close to the actual sliver, not only in terms of total irregularity but also in terms of the structural irregularity. The difference between the two is less than 5%, indicating that the fiber arrangement model proposed in this paper is close to the actual fiber arrangement in the sliver. Moreover, compared with other existing fiber arrangement models, it is found that this model can significantly improve the description accuracy of fiber arrangement in fiber assembly, especially for slivers and rovings. Therefore, the establishment of this model can provide a basis for the accurate prediction of spinning quality and intelligent development of spinning processing.

Three-dimensional architecture of the palmar plate of the thumb metacarpophalangeal joint in infant macaque.

The palmar plate is a crucial structural part of hand, associated with metacarpophalangeal and interphalangeal joints. Pediatric disorders involving the palmar plate of thumb metacarpophalangeal joint include trigger thumb, hyperextension, instability, and dislocation. While anatomical differences exist between children and adults, detailed microstructure evaluations in infants remain unexplored. In this study, we provide a histological and structural assessment of the previously unresolved microstructure of the palmar plate in the thumb metacarpophalangeal joint of infant Japanese macaques (Cercopithecidae, Macaca fuscata), a relevant model for human development. Histological staining (light microscopy) and scanning electron microscopy were employed to visualize the three-dimensional microstructure. The palmar plate of the infant macaque was found to contain (1) elastic fibers, (2) hyaline cartilage composed of type II collagen, and (3) type I collagen fibers arranged in distinct patterns. The cartilaginous region exhibited a reticulate fiber arrangement on its periphery, while the membranous region displayed dense and complex fibers on the proximal phalanx side and parallel on the metacarpal side, respectively. This is the first comprehensive three-dimensional investigation of the infant's thumb's palmar microanatomy, providing a foundation for understanding its development and implications for pediatric disorders.

Dynamic drop penetration of vertically oriented fiber arrays

This experimental work investigates the impact dynamics of drops on vertically oriented, three-dimensional-printed (3D-printed) fiber arrays with variations in packing density, fiber arrangement, and wettability. These fiber arrays are inspired by mammalian fur, and while not wholly representative of the entire morphological range of fur, they do reside within its spectrum. We define an aspect ratio, a modified fiber porosity relative to the drop size, that characterizes various impact regimes. Using energy conservation, we derive a model relating drop penetration depth in vertical fibers to the Weber number. In sparse fibers where the Ohnesorge number is less than 4×10−3, penetration depth scales linearly with the impact Weber number. In hydrophobic fibers, density reduces penetration depth when the contact angle is sufficiently high. Hydrophilic arrays have greater penetration than their hydrophobic counterparts due to capillarity, a result that contrasts the drop impact-initiated infiltration of horizontal fibers. Vertical capillary infiltration of the penetrated liquid is observed whenever the Bond number is less than 0.11. For hydrophilic fibers, we predict that higher density will promote drop penetration when the contact angle is sufficiently low. Complete infiltration by the drop is achieved at sufficient times regardless of drop impact velocity.

Different strategies towards strength: Unveiling the role of Zn vs Mn/Ca and chitin arrangement in scorpion stingers.

Arthropods and especially scorpions often use metal ions to harden their cuticle. In this study we analyse the chitin fibre arrangement, metal content and distribution and mechanical properties of the stingers of two scorpions: the buthid scorpion Centruroides platnicki (PS) and the diplocentrid scorpion Nebo whitei (NS). Results show that both scorpions incorporate the same elements, Zn, Mn and Ca, but in different locations in the stinger cuticle. While NS uses Zn ions as hardening agent in the epicuticle, PS uses Mn/Ca ions. Interestingly, Zn ions were also found in PS but had no impact on the enhancement of the mechanical properties of the stinger. The use of different metal ions in biological materials is likely to enable precise adjustments of material properties to suit not only mechanical but biological functions as well.

HIF-1α/HO-1-Mediated Ferroptosis Participates in Polystyrene Nanoplastics-Induced Intergenerational Cardiotoxicity.

To explore the intergenerational cardiotoxicity of nanoplastics, maternal mice were exposed to 60 nm polystyrene nanoplastics (PS-NP) during pregnancy and lactation. The results showed that PS-NP can enter the hearts of offspring and induce myocardial fiber arrangement disorder, acidophilic degeneration of cardiomyocytes, and elevated creatine kinase isoenzymes (CK-MB) and lactate dehydrogenase (LDH) levels after maternal exposure to PS-NP at 100 mg/kg during pregnancy and lactation. Mechanistically, KEGG analysis of RNA sequencing showed the participation of hypoxia-inducible factor-1 (HIF-1) and ferroptosis in PS-NP-induced cardiotoxicity. Key features of ferroptosis, including Fe2+ accumulation, mitochondrial injury, oxidative stress, GPX4 downregulation, and FTH1, ACSL4, and SLC7A11 upregulation, were detected. Furthermore, PS-NP treatment upregulated the expressions of HIF-1α and HO-1, and PS-NP-induced ferroptosis can be alleviated by inhibition of HIF-1α using si-HIF-1α. This study provided an insightful reference for the intergenerational cardiotoxicity assessment of PS-NP.

Alginate-polylysine-alginate (APA) microencapsulated transgenic human amniotic epithelial cells ameliorate fibrosis in hypertrophic scars.

Hypertrophic scar (HS) is a severe skin fibrosis. Transplanting stem cells carrying anti-fibrotic cytokine genes, like interferon-gamma (IFN-γ), is a novel therapeutic strategy. Human amniotic epithelial cells (hAECs) are ideal seed cells and gene vectors. Microencapsulation creates a favorable environment for transplanted cells. This study investigates the effect of alginate-polylysine-alginate (APA)-microencapsulated hAECs modified with IFN-γ on HS fibrosis. hAECs were isolated from human placentas and characterized. The full-length IFN-γ gene was cloned into the pcDNA3.1 vector to create the recombinant plasmid IFN-γ-pcDNA3.1. This plasmid was then transfected into hAECs, resulting in the generation of IFN-γ-modified hAECs (IFN-γ-hAECs). Subsequently, these IFN-γ-hAECs were microencapsulated with APA to produce APA-IFN-γ-hAECs. In vitro, the release of IFN-γ, as well as the cellular and metabolic activities, growth, proliferation, migration, apoptosis, and trans-differentiation were assessed using HS-derived fibroblasts. In vivo, the weight loss of HS xenografts, collagen fiber arrangement, tissue oxidative stress, and inflammatory response were evaluated using a nude mouse model that had been transplanted with human HS tissues. In vitro, APA-IFN-γ-hAECs exhibited significantly sustained and enhanced IFN-γ release, increased cellular vitality, and inhibited fibroblast growth, proliferation, migration, and trans-differentiation into myofibroblasts. APA-IFN-γ-hAECs also remarkably downregulated extracellular matrix (ECM) components and promoted apoptosis. In vivo, they significantly accelerated the weight reduction of HS xenografts, improved collagen fiber arrangement, and mitigated oxidative stress and inflammation. This study suggests that APA-microencapsulated IFN-γ-hAECs may have potential in alleviating HS fibrosis, offering a new direction for exploring effective clinical HS management strategies.

Investigating the effect of fiber arrangement on tensile properties of two-dimensional hybrid braided composite rods

Braided composites are gaining attention in the most industrial applications. To design rods with optimal tensile properties against combined loads, experimental studies were conducted to investigate the effect of using axial yarn and core in different categories on the tensile properties of braided reinforced composite rods. In this study, six types of braided composite rods with different arrangements of braid components (axial yarn or core type) were produced using glass and polyester fibers with epoxy resin as the matrix. The elastic modulus, ultimate tensile strength, and work of fracture of these rods were tested, and the experimental elastic modulus of samples were compared with previously developed models. Moreover, comparing the stress-strain results of the samples revealed that the produced hybrid samples demonstrate pseudo-ductile tensile behavior, showing varying trends as the type of reinforcement is altered. The results indicate that using a double-layer triaxial braid as reinforcement for the composite can increase the elastic modulus up to 13% compared to the similar single-layer sample. Additionally, employing a double-layer triaxial braid as reinforcement for the composite leads to a greater work of fracture. However, in terms of ultimate tensile strength, biaxial braid reinforcement demonstrates better performance in reinforcing the composite rods.

3D-Printed Myocardium-Specific Structure Enhances Maturation and Therapeutic Efficacy of Engineered Heart Tissue in Myocardial Infarction.

Despite advancements in engineered heart tissue (EHT), challenges persist in achieving accurate dimensional accuracy of scaffolds and maturing human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), a primary source of functional cardiac cells. Drawing inspiration from cardiac muscle fiber arrangement, a three-dimensional (3D)-printed multi-layered microporous polycaprolactone (PCL) scaffold is created with interlayer angles set at 45° to replicate the precise structure of native cardiac tissue. Compared with the control group and 90° PCL scaffolds, the 45° PCL scaffolds exhibited superior biocompatibility for cell culture and improved hiPSC-CM maturation in calcium handling. RNA sequencing demonstrated that the 45° PCL scaffold promotes the mature phenotype in hiPSC-CMs by upregulating ion channel genes. Using the 45° PCL scaffold, a multi-cellular EHT is successfully constructed, incorporating human cardiomyocytes, endothelial cells, and mesenchymal stem cells. These complex EHTs significantly enhanced hiPSC-CM engraftment in vivo, attenuated ventricular remodeling, and improved cardiac function in mouse myocardial infarction. In summary, the myocardium-specific structured EHT developed in this study represents a promising advancement in cardiovascular regenerative medicine.

SMILE-Derived Corneal Stromal Lenticule: Experimental Study as a Corneal Repair Material and Drug Carrier.

A detailed study of the physicochemical properties of SMILE-derived lenticules and evaluation of their drug delivery after loading with silver nanoparticles (AgNPs). The lenticules were decellularized and modified with crosslinking concentrations of 0.01 (0.01E/L), 0.05 (0.05E/L), and 0.25 (0.25E/L) mmol N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) per mg lenticule at 5:1 carbodiimide/N-hydroxysuccinimide (EDC/NHS) ratios. The degree of swelling, light transmittance, biomechanical properties, and stability of the non-crosslinked decellularized lenticules (DLs), 0.01E/L, 0.05E/L, and 0.25E/L were measured and characterized using Fourier transform infrared spectroscopy and transmission electron microscopy with non-crosslinked non-decellularized lenticules as controls. DLs, 0.01E/L, 0.05E/L, and 0.25E/L were soaked in AgNPs for 24 hours, and the concentration of the drug released was measured. There was no significant difference in the degree of swelling between the groups (P > 0.05). The light transmittance of the lenticules did not change after decellularization and crosslinking and decreased after loading with AgNPs. Non-decellularized lenticules biodegraded within 108 to 120 hours, and the other groups biodegraded within 96 to 108 hours in vitro. The 0.01E/L had the highest tensile strength. The absorption peak intensity ratio of the amide I band and the amide II band decreased, and the arrangement of collagen fibers was more compact in crosslinked decellularized lenticules. The 0.01E/L had the highest cumulative drug release (3.4 ± 0.91 μg). Crosslinking decellularization improved the biomechanical properties and resistance to water absorption of lenticules, increased covalent bonds between collagen fibers, and improved drug delivery. Crosslinked decellularized lenticules can be used as a new corneal patch material and drug delivery carrier for drug AgNPs.

Effects of chitosan-gentianic acid derivatives on myofibrillar proteins in sea bass (Lateolabrax maculatus) during refrigerated storage.

Phenolic acid-chitosan derivatives have received extensive attention due to their greatly enhanced mechanical, antibacterial and antioxidant properties, especially in food preservation. The chitosan-gentianic acid (CS-g-GA) was prepared and its impact on myofibrillar proteins (MPs) in sea bass (Lateolabrax maculatus) during refrigerated storage was investigated in this study. Fish fillets were immersed in distilled water, CS, GA and CS-g-GA solutions, respectively, followed by an 18-day refrigerated storage. MPs were extracted from fish fillets every 3days, and then the degree of oxidation and conformational changes of MPs were evaluated. The results of myofibril fragmentation index (MFI) and surface hydrophobicity confirmed that CS-g-GA can retard the fragmentation and degradation of myofibrils. Additionally, the total sulfhydryl content of CS-g-GA-treated samples in the later storage was significantly higher than those of other groups, confirming that CS-g-GA treatment protected the structure and function of protein. Results of Fourier transform infrared spectroscopy (FT-IR) and inner fluorescence intensity (IFI) showed that CS-g-GA maintained the secondary and tertiary structure of MPs. The results from scanning electron microscope (SEM) further clarified that CS-g-GA can maintain the tight arrangement of muscle fibers and protect the microstructure of myofibrils. Furthermore, the observation of confocal laser scanning microscopy (CLSM) demonstrated that CS-g-GA can prevent protein cross-linking and aggregation. Therefore, CS-g-GA treatment can effectively protect the structure and delay the oxidation of MPs.

Histopathological Effect of Aqua Fix Supplementation on the Skeletal Muscle and Liver of Labeo rohita (Hamilton,1822) during Immunomodulation and Aeromoniasis

The impact of oral feeding diet (supplement) Aqua Fix was studied on the histopathological changes in skeletal muscles and liver of L.rohita during immunomodulation and aeromoniasis. Three groups (D,E,F) of six months old fish were employed; groups D and E were treated with Aqua Fix for 4 days, on day 5 fish of group E and F were infected with Aeromonas hydrophila @ 10-6CFU/fish(fish of group F were fed with normal diet for 4 days).Controls (group G) were untreated and uninfected. Histological examination of the skeletal muscle and liver tissues were carried out on selected days of experimentation (day 1 and day 4 of experiment). The stained sections were observed under microscope and histological changes were noted. Immunostimulated fish (group D) showed normal arrangement of muscle fibers and muscle bundles compared to other groups (E and F) of fish. Both the muscle fibers and muscle bundles were healthy as in controls (Group G). In infected group (untreated with Aqua Fix, group F), fragmentation of muscle fibers was noticed along with sarcoplasmic debris. Dermal lesions and moderate edema is noticed in necrotic muscle fibers. Liver in immunostimulated fish showed large, polygonal hepatocytes with distinct, round nuclei. Hepatic central vein and sinusoids were clearly visible. By day 1 of infection, liver exhibited necrosis of hepatocytes, pycnosis of hepatocyte nuclei, granulation and vacuolisation (group F). Dilation of hepatic vein and sinusoids were observed. Necrotic foci and haemorrhages were evident in the capillaries of liver and occurred more severely in group F compared to group E (treated with Aqua Fix and infected). The fish (group E) which received immunostimulant and infection showed moderate effect on liver suggesting that Aqua Fix supplementation ameliorate the ill effects of A. hydrophila, showing the positive influence of herbal immunostiomulant i.e, Aqua Fix in fresh water fish.

Simulation of fiber arrangement in slivers based on image processing

The fiber arrangement in a sliver has a significant effect on sliver quality, especially on its evenness. In this work, a novel method was developed to simulate fiber arrangement based on the variation fineness of each sliver subsegment relative to the mean sliver fineness, which was acquired from the tested sliver unevenness curve by image processing. The modeling results of viscose indicated that the non-random fiber arrangement in the sliver could be appropriately and graphically expressed by the variation in the fineness of each sliver subsection relative to the mean sliver fineness. The results further indicated that the simulated fiber arrangements in the sliver were in line with actual ones. Moreover, the relative errors between the irregularities calculated from the fiber arrangement in the sliver and those measured were less than 8%, whereas the relative errors between the simulated values from the random fiber arrangement and those tested were approximately 95%. The obtained simulation results demonstrated that this new method accurately simulated the non-random fiber arrangement in the sliver and provided an accurate prediction of sliver irregularity in the further post-spinning processes.

Crystalline structures in foams: guided mechanical self-assembly of bubbles in fiber arrays

Abstract Spontaneous mechanical self-assembly of monodisperse bubbles generally leads to disordered foams at low density. Producing crystalline structures requires specific care: for example, Kelvin foams—periodic assemblies of bubbles arranged on a body-centered cubic lattice—are a typical example of a structure which is challenging to obtain experimentally, despite it being a local minimum of energy. Here we show how bubbling in different arrangements of fibers enables to control foam architectures through a guided mechanical self-assembly of bubbles: for optimal ratios of bubble size to fiber spacing, Kelvin and hexagonal close packing crystalline foams are formed in square and hexagonal fiber arrays, respectively. The long-range crystalline architectures achieved in samples spanning hundreds of bubbles are then quantified through a theoretical approach analysing the orientational order in the samples. This methodology, based on the decomposition of strut orientations via spherical harmonics, is inspired by the so-called Steinhardt’s coefficients, developed for quantifying rotational order in 3D liquids. Beyond the achievement of architecting liquid foam structures, our work demonstrates that the obtained ordering persists upon solidification of initially liquid polymeric foams, using alginate and polyurethane foams in nylon fiber arrays as model systems. The mechanically guided self-assembly of bubbles offers an attractive alternative to additive manufacturing to generate highly ordered architected polymeric materials.

Generation of Bio-Based, Shape- and Temperature-Stable Three-Dimensional Nonwoven Structures Using Different Polyhydroxyalkanoates.

Recent research has shown the potential of polyhydroxyalkanoates (PHAs), particularly poly(3-hydroxybutyrate) (P3HB), to form nonwoven structures with fine fiber diameter distributions ranging from 2.5 µm to 20 µm during the meltblow process. The shortcomings of existing fabrics of this type include high brittleness, low elongation at break (max. 3%), and a lack of flexibility. Furthermore, the high melt adhesion and the special crystallization kinetics of PHAs have commonly been regarded as constraints in filament and nonwoven processing so far. However, these two properties have now been used to elaborate a three-dimensional fiber arrangement on a matrix, resulting in the creation of dimensionally and temperature-stable "nonwoven-parts". Moreover, this study investigated the PHA copolymer poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), revealing a similar processability to P3HB and PHBV in the meltblow process. A significant increase in the (peak load) elongation in the machine direction was observed, reaching values between 5% and 10%, while the tensile strength retained unaltered. The addition of the bio-based plasticizer acetyltributylcitrate (ATBC) to PHBH resulted on an increase in elongation up to 15%. The three-dimensional fabric structure of PHBH exhibited complete resilience to compression, a property that differentiates it from both P3HB and PHBV. However, the addition of the plasticizer to P3HB did not lead to any improvements. This interesting array of properties results in moderate air permeability and hydrophobicity, leading to impermeability to water.

Long-Pulse Thermography Application for Detection and Localisation of Embedded Optical Fibres into Glass Fibre Composite.

Composites have found applications in critical components and require a high degree of safety and reliability. To ensure this, structural health monitoring systems based on optical fibres embedded within structures are installed for continuous monitoring. Infrared thermography is a non-destructive method that can be applied to inspect the internal structure after manufacturing and during operation. This paper presents an application of pulsed thermography for observing and evaluating the internal structure of glass fibre-reinforced polymer samples with different arrangements of embedded optical fibres. The goal of the paper is to study the feasibility of using pulsed thermography to distinguish optical fibres from glass textile fibre bundles, as well as to track the arrangement of the optical fibres.

A Review on the Application of Animal-Based Materials Using Three-Dimensional (3D) Printing and Protein Restructuring Technologies.

Production of alternative proteins is crucial for the development of future protein resources. This study explored the creation of sustainable animal resources by combining extrusion molding and three-dimensional (3D) printing technologies. Extrusion effectively organizes vegetable proteins at high temperatures and pressures to replicate meat-like textures, and high-moisture extrusion successfully mimics the fiber structure of conventional meat. However, many meat analogs products still differ from conventional meat in terms of sensory properties such as texture, juiciness, and flavor, indicating the need for quality improvement. Researchers have leveraged 3D printing technology to incorporate fat analogs and enhance the appearance and texture through muscle fiber simulation. This technology allows for precise arrangement of muscle fibers, formation of adipose tissue, and marbling, thereby improving the overall sensory experience. By combining extrusion and 3D printing, we can enhance the nutritional and organoleptic qualities of meat analogs, ultimately meeting consumer expectations and achieving a balance between plant- and animal-based materials.

Role of the nuclear factor-kappa B signaling pathway in the repair of white matter injury in neonatal rats through human umbilical cord mesenchymal stem cell transplantation

To observe the reparative effects of human umbilical cord mesenchymal stem cell (hUC-MSC) transplantation on white matter injury (WMI) in neonatal rats and explore its mechanism through the nuclear factor-kappa B (NF-κB) signaling pathway mediated by microglial cells. Sprague-Dawley rats, aged 2 days, were randomly divided into three groups: sham-operation,WMI, and hUC-MSC (n=18 each). Fourteen days after modeling, hematoxylin-eosin staining was used to observe pathological changes in the white matter, and immunofluorescence staining was used to measure the expression level of ionized calcium-binding adapter molecule 1 (Iba1). Western blotting was used to measure the protein expression levels of inhibitory subunit of nuclear factor-kappa B alpha (IκBα), phosphorylated IκBα (p-IκBα), phosphorylated NF-κB p65 (p-NF-κB p65), myelin basic protein (MBP), and neuron-specific nuclear protein (NeuN). Quantitative real-time PCR was used to assess the mRNA expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), MBP, and NeuN. Immunohistochemistry was used to measure the protein expression levels of MBP and NeuN. On day 28, the Morris water maze test was used to evaluate spatial cognitive ability. Fourteen days after modeling, the sham-operation group exhibited intact white matter structure with normal cell morphology and orderly nerve fiber arrangement. In the WMI group, large-scale cell degeneration and necrosis were observed, and nerve fiber arrangement was disordered. The hUC-MSC group showed relatively normal cell morphology and more orderly nerve fibers. Compared with the sham-operation group, the WMI group had significantly higher proportions of Iba1-positive cells, increased protein levels of p-IκBα and p-NF-κB p65, and higher mRNA levels of TNF-α and IL-1β. The protein expression of IκBα and the positive expression of MBP and NeuN, as well as their protein and mRNA levels, were significantly reduced in the WMI group (P<0.05). Compared with the WMI group, the hUC-MSC group showed reduced proportions of Iba1-positive cells, decreased protein levels of p-IκBα and p-NF-κB p65, and lower mRNA levels of TNF-α and IL-1β. Furthermore, IκBα protein expression and MBP and NeuN expression (both at the protein and mRNA levels) were significantly increased in the hUC-MSC group (P<0.05). On day 28, the Morris water maze results showed that compared with the sham-operation group, the WMI group had significantly longer escape latency and fewer platform crossings (P<0.05). In contrast, the hUC-MSC group had significantly shorter escape latency and more platform crossings than the WMI group (P<0.05). hUC-MSC transplantation can repair WMI in neonatal rats, promote the maturation of oligodendrocytes, and support neuronal survival, likely by inhibiting activation of the NF-κB signaling pathway mediated by microglial cells.

The Influence of Fiberglass Fiber Arrangement Variations on the Tensile and Bending Strength of Ships

The use of Fiberglass Reinforced Plastic (FRP) as a substitute for wood in the shipbuilding industry in Indonesia is increasing, particularly in small vessels under 5 GT. Challenges in obtaining high-quality wood have driven fishermen and the shipbuilding industry to shift towards composite chopped materials such as fiberglass. This research aims to evaluate the tensile and bending strengths of fiberglass composites made using the hand lay-up method with variations of random fiber layers as well as fibers oriented at 0° and 90°. The tests were conducted according to ASTM D638-14 and D790 standards, with the results showing that the chopped-woven-hybrid fiber configuration produced the highest tensile strength of 38.174 MPa, while the chopped-chopped-woven-woven configuration produced the highest bending strength of 104.44 MPa. However, all the tested fiber layer variations did not meet the standards of the Indonesian Classification Bureau (BKI), indicating the need for further optimization in layer arrangement to achieve the desired quality. Additionally, the FRP boat-building training program conducted in Gisik Cemandi Village demonstrated that traditional boat craftsmen can adapt to this new technology, which offers an effective solution to wood scarcity while enhancing the quality and safety of vessels. This research supports the development of FRP as a more reliable, efficient, and environmentally friendly material for shipbuilding, particularly in the fisheries and small shipping sectors in Indonesia. The broader adoption of FRP technology is expected to address environmental and economic challenges in the national shipbuilding industry

Effect of steel fibers on the stress–strain behaviour of aligned steel fiber ultra-high performance concrete under uniaxial compression

The mechanical properties of ultra-high performance concrete (UHPC) can be significantly enhanced by aligning the fibers. Aligned steel fiber UHPC (ASF-UHPC) was fabricated using a uniform magnetic field, yet the corresponding stress-strain relationship has not been extensively studied, hindering accurate calculations. To address this gap, ASF-UHPC was prepared and subsequently subjected to CT scans and uniaxial compression tests to investigate its stress-strain behavior. The analysis of failure mode and stress-strain curves revealed distinct anisotropic characteristics in compressive stresses and fiber distributions. Various steel fiber parameters, including the alignment orientation, volume fraction, and length, were systematically analysed to assess their impact on the material properties. A unit-cell model was developed to elucidate the influence of the fiber alignment orientation on UHPC performance. The results demonstrate that a parallel fiber alignment significantly enhances the elastic modulus, albeit with a Poisson ratio similar to that of the matrix, owing to the limited lateral confinement. Conversely, perpendicular fiber alignment restrains lateral deformation, enhancing the material strength and toughness. Randomly distributed fibers offered a degree of horizontal confinement, whereas inclined fibers induced horizontal thrust, leading to excessive lateral deformation and consequent elevation of the Poisson ratio. Finally, predictive equations for UHPC elastic modulus and compressive strength, along with an analysis model for stress-strain characteristics, were refined taking into account the direction of fiber arrangement.

Vanillic acid attenuates doxorubicin-induced cardiotoxicity by regulating PINK1/Parkin/Mfn2 signaling pathway

ObjectivesThe aim of this study was to explore the potential protective effects of vanillic acid (VA) against doxorubicin (DOX)-induced cardiotoxicity and unravel the underlying molecular mechanisms involved. MethodsThe DOX -induced myocardial toxicity model was established in Sprague-Dawley (SD) rats by intraperitoneal injection of doxorubicin. Simultaneously, different concentrations of VA were administered for intervention. After modeling, rat cardiac function was evaluated using an ultrasound machine. The detection of creatine kinase isoenzyme MB (CK-MB) levels in rat serum using a biochemical analyzer. HE staining method was used to observe myocardial pathological changes, Masson's trichrome staining was performed to assess the degree of myocardial fibrosis. The observation of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) levels in myocardial tissue using assay kits. Western blotting and immunohistochemistry was conducted to detect protein expression levels of PINK1, Parkin, P62, LC3I/II, Mfn2, Drp1, OPA, and Fis1. ResultsCompared to the DOX group, intervention with VA demonstrates ameliorative effects on doxorubicin-induced cardiotoxicity, as evidenced by improvements in left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS), and a reduction in left ventricular end-diastolic diameter (LVEDd) in rats. Additionally, the application of VA reduced the levels of CK-MB in rat serum. However, there were no statistically significant differences observed in heart rate. Histological examination reveals that VA administration positively impacts the arrangement of myocardial fibers and mitigates myocardial fibrosis in the rat hearts subjected to doxorubicin-induced injury. Moreover, relative to the DOX group, the use of VA alleviates DOX-induced myocardial cell apoptosis. VA treatment also upregulates the expression levels of PINK1 and Parkin, leading to the activation of mitochondrial autophagy. Furthermore, VA enhances the expression levels of mitochondrial dynamics proteins Mfn2, Drp1, and Fis1 while downregulating the expression of OPA. Among them, the high-dose group of VA (60 mg/kg·d) showed the most pronounced improvement in DOX-induced cardiotoxicity. ConclusionVA attenuated DOX-induced myocardial injury by up regulating the PINK1/Parkin/Mfn2 signaling pathway.