Sheath Fibers Research Articles

AXDND1, a novel testis-enriched gene, is required for spermiogenesis and male fertility

Spermiogenesis is a complex process depending on the sophisticated coordination of a myriad of testis-enriched gene regulations. The regulatory pathways that coordinate this process are not well understood, and we demonstrate here that AXDND1, as a novel testis-enriched gene is essential for spermiogenesis and male fertility. AXDND1 is exclusively expressed in the round and elongating spermatids in humans and mice. We identified two potentially deleterious mutations of AXDND1 unique to non‐obstructive azoospermia (NOA) patients through selected exonic sequencing. Importantly, Axdnd1 knockout males are sterile with reduced testis size caused by increased germ cell apoptosis and sloughing, exhibiting phenotypes consistent with oligoasthenoteratozoospermia. Axdnd1 mutated late spermatids showed head deformation, outer doublet microtubules deficiency in the axoneme, and loss of corresponding accessory structures, including outer dense fiber (ODF) and mitochondria sheath. These phenotypes were probably due to the perturbed behavior of the manchette, a dynamic structure where AXDND1 was localized. Our findings establish AXDND1 as a novel testis-enrich gene essential for spermiogenesis and male fertility probably by regulating the manchette dynamics, spermatid head shaping, sperm flagellum assembly.

Intelligent analysis technology of bamboo structure. Part I: The variability of vascular bundles and fiber sheath area

The vascular bundle is the most important structural unit of bamboo that determines the growth of bamboo and the properties of bamboo-based materials. A systematic understanding of the characteristics of vascular bundle is the key to clarify the structure-property relationship of bamboo. In this paper, the YOLO (You Only Look Once) algorithm was applied to the field of bamboo structure and a detection model was proposed to solve the key technical problems regarding automatic detection, positioning, counting, and automatic measurement of relevant parameters of vascular bundles. The precision of the detection model was up to 99.59 %, and able to achieve the work in minutes that cannot be done manually. Furthermore, we studied the variation of inter-plant and the variation of axial direction of Moso bamboo [Phyllostachys edulis (Carr)H. de Lebaie]. The results indicated that the total number of vascular bundles of Moso bamboo from 12 different areas was 7196 ± 698, the distribution density of vascular bundles was 2.49 ± 0.58 per mm2, the fiber volume fraction was 23.68 ± 1.89 %. The apparent differences of vascular bundles in different areas result from the growing environment. There were approximately 8000 vascular bundles in the base of Moso bamboo while the number decreased to around 300 at the top, and the decreased vascular bundles were mainly semi-open type and open type. The total area of fiber sheath decreased linearly from base to top of internodes, while the fiber volume fraction was 20–30 % constantly.

Impact of abrasion on strength, elasticity and elastic recovery properties of stretch-denim fabric

PurposeIn recent times, the usage of elastane-containing denim garments has increased, as it provides fit and comfort both at the same time. The purpose of the study is to understand the effect of abrasion on the durability of comfort related to body movement and shape retention property of the stretch-denim fabric.Design/methodology/approachThe paper investigates the effect of abrasion on the initial tensile properties, recovery and resilience properties of the stretch-denim fabric. Further, to analyse the effect of the composition of the elastane yarn, three different types of elastane yarns having different types of sheath (covering) fibre, structure and different levels of elastane content have been used in the weft.FindingsThe comfort related to body movement and the shape retention properties of the stretch-denim fabric got affected due to abrasive damage. The elastane yarn composition and structure played an important role in determining the extent of the change in such properties during abrasion. The fabric with a higher level of elastane content suffered a greater loss in shape-retention properties due to abrasion. The extent of mass loss in stretch-denim fabric does not always correlate to the extent of loss in the comfort and shape-retention properties.Originality/valueMost of the earlier studies have investigated the effect of abrasion on the durability aspect of the stretch-denim fabric. In a practical scenario, the stretch-denim garments are rarely discarded due to tearing or change in appearance but mainly due to bagging, i.e. distortion in shape after usage. Thus, the study on the combined effect of the abrasion and cyclic loading on the comfort and shape-retention properties will help to predict the performance of the apparel during usage.

A Study on Erosion Wear Behavior of Alkaline and Silane Modified Coconut Sheath and Red Mud Reinforced Hybrid Composites

ABSTRACT In the present work, the effect of erosion variable on the erosion rate of the novel coconut sheath fiber and red mud reinforced polyester composites is evaluated. The composites are fabricated with three forms of fiber reinforcement. Erosion experiment is conducted as per the ASTM G76 by varying impact angle, erodent velocity, and erodent discharge rate. The experiment design is modeled using the central composite design and analyzed using the response surface methodology and analysis of variance technique. The impact angle is found to be the most significant factor affecting the composite erosion rate. From erosion wear analysis, it is found that the interfacial adhesion between the fiber matrix is critical in the reduction of erosion rate. The composite with silane treated fiber showed reduced erosion rate when compared to the untreated and alkaline treated fiber composites. Further, the wear mechanism was analyzed on the eroded specimen using SEM analysis. Finally, the multiple response optimization was carried out using the desirability function method and found that erosion rate can be minimized at impact angle of 90°, erodent discharge rate of 4.45 g/m, and erodent velocity of 70 m/s.

Cell wall polymer distribution in bamboo visualized with in situ imaging FTIR

To better understand the high recalcitrance of bamboo during bioconversion, the fine spatial distribution of polymers in bamboo was studied with Imaging FTIR microscopy under both transmission and ATR modes, combined with PCA data processing. The results demonstrated that lignin, xylan and hydroxycinnamic acid (HCA) were more concentrated in the fibers near the xylem conduit, while cellulose was evenly distributed across the whole fiber sheath. PCA processing produced a clear separation between bamboo fibers and parenchyma cells, indicating that the parenchyma cells contains more pectin and HCA than fibers. It also demonstrated that cellulose, xylan and S-lignin were concentrated most heavily in bamboo fiber secondary cell walls, while G-lignin, pectin and HCA were found more in the compound middle lamella. The revealed information regarding polymer distribution is of great significance for better understanding of the inherent design mechanism of plant cell wall and its efficient utilization.

Stretchable and wearable conductometric VOC sensors based on microstructured MXene/polyurethane core-sheath fibers

Emerging wearable electronics pose urgent needs for high-performance, wearable gas sensors. However, the state-of-the-art gas sensors based on planer interdigited electrodes (IE) are commonly flexible yet not stretchable, which is not desirable for integration with human skin or clothing. Here, we report the fabrication of a stretchable and wearable gas sensor by using MXene/polyurethane (PU) core-sheath fibers. The synergetic effects of charge transfer and swelling-induced stretching offer the MXene/PU fiber sensor with high sensitivity to acetone (5–325 fold higher than planer MXene sensor deposited on an IE), wide sensing range (from ppb level to saturated vapor), and high signal-to-noise ratio (SNR, 160 % higher than planer MXene sensor). To further improve the sensing performance of the MXene/PU fiber, microstructures including microcracks and microwrinkles were developed into the fiber sheath. The microcracks can amplify the swelling-induced resistance variation of the conductive sheath; and therefore, leading to an enhanced sensing response 40 % higher than the flat core-sheath fiber. Furthermore, by developing microwrinkles onto the conductive sheath, a highly stretchable fiber-based gas sensor has been successfully demonstrated, which can accommodate human skin deformation (30 %) with a minimal sensing interference from tensile strain. The as-reported MXene/PU fibers can be knitted into clothing and serve as wearable gas sensors with good sensing reliability and gas permeability. Our results provide insight in utilizing microstructure engineering to tailor the sensing performance of gas sensors.

Fabrication, microstructural and mechanical properties of arecanut leaf sheath fibre reinforced polyester resin composites

Arecanut leaf sheath (ANLS) an unexplored agricultural biomass is used to recover long staple lignocellulosic fibers. A long staple lignocellulosic fiber is extracted from ANLS biomass using 8% NaOH treatment. As reinforcing material ANLS fibre properties such as fibre length, diameter, moisture content, single fibre strength and X-ray diffraction analysis were carried out. Three types of composites, 15, 20 and 25 (w/w)% fibre loading composites have been prepared in unsaturated polyester resin matrix. The tensile, flexural and interlaminar shear strength (ILSS) properties and void content of these composites are studied. The tensile fracture behaviors of fibre and composites are studied with the help of scanning electron micrographs.

English

Schwannomas are relatively rare benign neoplasms of neurogenic origin from the neural sheath of peripheral nerves occurring more commonly in the head and neck. Mandibular bone is the commonest site of occurrence of these nerve lesions. Radiographically, intraosseous schwannoma of mandible is very difficult to differentiate from other bony pathologies such as neurofibroma, ameloblastoma, fibrous dysplasia, myxoma, central giant cell lesion, or periapical lesion, so it should be included in the differential diagnosis of lower jaw swelling. Schwannoma as a pathologic entity was first reported in 1910 by Verocay. Schwannoma (also known as neurinoma, neurolemmoma, neurilemmoma, perineural fibroblastoma, and peripheral nerve sheath tumour) is a rare, slowgrowing, benign neurogenic neoplasm that originated from Schwann cells. Schwann cells cover myelinated sheath of nerve fibres.1 These intraosseous schwannomas account for not more than 1 % of the central neoplasms. More than one third of all schwannomas are found in the head and neck region. 2 Most of these originate from the lower cranial nerve and sympathetic nervous system. Schwannomas from the upper cranial nerves such as trigeminal nerve and its branches are less common. Other commonly reported sites include the vertebra, clavicle, ribs, sacrum, humerus, ulna radius, etc. This painless slow-growing neoplasm may develop at any age.

Dual Function of Modified Palm Leaf Sheath Fibers in Adsorbing Reactive Yellow 3 and Cr(VI) From Dyeing Wastewater

The safe and effective treatment for dyeing wastewater including harmful metal ions, which are important environmental pollution sources, has not been solved in the realistic industry. Using natural materials with short regeneration cycle should be valued in recognized and effective adsorption techniques. In this study, hydroxyl-rich tannin molecules were successfully modified on palm leaf sheath fibers (PLSF) to obtain multifunctional adsorbent for simultaneous removal of dye molecules and heavy metal ions in dyeing wastewater. As a result, modified PLSF can effectively adsorb reactive yellow 3 (RY3) dye molecules with a maximum adsorption capacity of 83.19 mg/g from dyeing wastewater, while the sample loaded with RY3 can adsorb Cr(VI) with a maximum adsorption capacity of 189.48 mg/g. XRD, SEM, FT-IR, and stereomicroscope are used to characterize the adsorbent samples. The kinetic and thermodynamic analysis results show that the adsorption of RY3 and Cr(VI) by the adsorbent is consistent with pseudo-second-order kinetics and the Langmuir isotherm model. The thermodynamic parameters of Cr(VI) adsorption indicate that adsorption is a spontaneous endothermic process and has good reusability of Cr(VI).

Surface Modification of Areca Fibre by Benzoyl Peroxide and Mechanical Behaviour of Areca-Epoxy Composites

Natural fibre composites are playing great role in current life scenario where the focus is more on replacing synthetic fibre composites with natural fibre composites. In this current study, investigation was done on tensile and flexural behaviour of benzoyl peroxide treated areca sheath fibre epoxy composites. The surface modification of the fibre was confirmed by FTIR analysis. Treatment concentration was the major criteria which effects mechanical properties of the composites. At 4% concentration tensile strength and flexural strength was found to be maximum which was reported as 37.05 N/mm2 and 235.5 N/mm2 respectively which gradually decreased with increasing concentration of benzoyl peroxide. SEM analysis proved that at lesser concentration, the bonding between fibre and resin was effective which reduced as the concentration of benzoyl peroxide increased. This results in ineffective stress transfer between reinforcing material and the matrix which was the reason for failure of composites manufactured at higher treatment concentration.

Selection of dual-core yarn production parameters for denim fabric by using MULTIMOORA method

Dual-core yarn structures, one of the hybrid yarn types preferred in denim fabric structures recently, make it possible to improve the stretch properties of fabrics and to profit from the features of two or more materials simultaneously. In this study, innovative dual-core yarn structures containing elastane and wool yarn cores and cotton fiber as sheath fibers were developed by changing production parameters (twist, cores draft ratio). It is thought that innovative, relatively more natural denim fabrics with increased thermal insulation can produce with dual-core yarns containing wool fiber. The yarn type that meets the expectations of denim manufacturers among the 27 yarn types was selected with Multi-Objective Optimization on the Basis of Ratio Analysis (MOORA) from multi-criteria decision-making methods, and production parameters were determined. According to the MULTIMOORA method and expert opinion, 16 coded dual-core yarn sample (670 T/m, 1.05 wool draft ratio, and 3.3 elastane draft ratio) was the best alternative, and eight coded dual-core yarn sample (585 T/m, 3.5 elastane draft ratio, and 1.05 wool draft ratio) was the worst alternative found for denim fabric production.

Low-Intensity Pulsed Ultrasound Prompts Both Functional and Histologic Improvements While Upregulating the Brain-Derived Neurotrophic Factor Expression after Sciatic Crush Injury in Rats

The aim of this study was to determine that low-intensity pulsed ultrasound (LIPUS) at an intensity of 140 mW/cm2 promotes functional and histologic improvements in sciatic nerve crush injury in a rat model and to investigate changes over time in relevant growth factors and receptors, exploring the mechanism of LIPUS in the recovery process after injury. Toe angle in the toe-off phase, regenerative axonal length, myelinated nerve fiber density, diameter of myelinated nerve fiber, axon diameter and myelin sheath thickness were significantly higher in the LIPUS group than in the sham group. Gene and protein expression of brain-derived neurotrophic factor (BDNF) was upregulated in the LIPUS group. In conclusion, LIPUS contributed to rapid functional and histologic improvement and upregulated BDNF expression after sciatic nerve crush injury in rats.

Preclinical experience with a novel single-port platform for transoral surgery

BackgroundWe investigated a novel minimally invasive surgical platform for use in the oropharynx, hypopharynx, and larynx for single-port transoral surgery used in concert with standard transoral laryngeal and pharyngeal instrumentation.MethodsThe preclinical investigational device by Fortimedix Surgical B.V. (Netherlands) features two channels for manually controlled flexible articulating surgical instruments. A third central channel accepts both rigid and flexible endoscopes. The system is coupled to a standard laryngoscope for transoral access. In three cadaver models, we evaluated the surgical capabilities using wristed grasping instruments, microlaryngeal scissors, monopolar cautery, and a laser fiber sheath. Procedures were performed within the oropharynx, supraglottis, glottis, subglottis, and hypopharynx.ResultsWithin the oropharynx, we found adequate strength, range of motion, and dexterity to perform lateral oropharyngectomy and tongue base resection. Within the larynx, visualization was achieved with a variety of instruments including a flexible, 0° and 30° rigid endoscope. The glottis, supraglottis, pyriform sinuses, post-cricoid space, and esophageal inlet were readily accessible. Visualization and manipulation of grasping, laser, and monopolar cautery instruments were also possible within the subglottis. Instrument reach and accuracy facilitated completion of a delicate micro-flap on the true vocal fold. Other procedures included vocal fold resection, cricopharyngeal myotomy, and resection of subglottic mucosa.ConclusionsFrom this initial proof of concept experience with this novel platform, we found a wide range of procedures within the oropharynx, larynx, and hypopharynx to be feasible. Further work is needed to evaluate its applicability to the clinical setting. The ability of this platform to be used with conventional instrumentation may provide an opportunity for complex transoral surgery to be performed in a facile manner at greatly reduced cost.

Benfotiamine reduced collagen IV contents of sciatic nerve in hyperglycemic rats.

Neuropathy as a common complication of hyperglycemia in diabetic patients is probably caused by metabolic and structural changes in extracellular matrix (ECM) of peripheral nerves. This study was designed to evaluate the effects of benfotiamine (BT) on the structural, biological and mechanical characteristics of rat sciatic nerve in hyperglycemic condition. Forty eight adult male Wistar rats were assigned to 6 groups (n = 8): control (healthy rats with no treatment; C), positive control (healthy rats received BT treatment; B), negative control groups 1&2 (hyperglycemic rats kept for 4 and/or 8 weeks; 4WD and 8WD, respectively) and experimental groups 1&2 (hyperglycemic rats treated by daily oral gavage of 100mg kg- 1 body weight BT for 4 and/or 8 weeks; 4WD + BT and 8WD + BT, respectively). Hyperglycemia was induced by a single intraperitoneal injection of of streptozotocin (55mg kg- 1 body weight). After a period of experimental period (4 and/or 8 weeks) rats were sacrificed and from each two segments (1cm length) of left sciatic nerve were sampled. These samples were prepared for histological examinations (light and electron microscopy), collagen IV immunohistochemistry and strength tensile test. In comparison to control groups, in 4WD and 8WD groups the amount of type IV collagen was increased, the structure of myelin sheath and nerve fibers were extensively altered and the tensile strength was significantly decreased (p < 0.05) while in 4WD + BT and 8WD + BT groups these abnormalities were attenuated. It seems that BT treatment may rescue the sciatic nerve from the hyperglycemic-induced ECM structural abnormality. This beneficial advantage of BT is likely exerted through the modification of glucose metabolism pathways.

Physical, chemical and surface morphological characterization of single areca sheath fiber

The technological advance in various streams necessitated the increased demand for lesser weight and minimal cost materials. The concerns to ensure environmental sustainability, those newer materials were expected to be decomposable. In the current study, chemical, physical and mechanical and morphological aspects of areca sheath/frond fiber are investigated. It is observed that, the cellulose, hemicelluloses and lignin wt. % are 65.02, 8.26 and 18.62 respectively. The XRD study confirms the percent crystallinity of 81.33% and the crystallinity index of 0.77. The fiber further exhibited the tensile strength of 59.62±2.20 MPa. The TGA study reveals the higher degradation rate at 322.2 °C and the residual mass at 500 °C is 33.23%. The morphological study is done through scanning electron microscopy (SEM). The other properties such as density (0.9 g/cm3), the fiber length, diameter, and moisture uptake are also reported. From the very promising results, the fiber can be used as a reinforcement agent and the composites may find potential applications in automobile panels, interiors, structural light weight bearing sheets, etc.

Mechanical characterization of plant fortified fiber polymer composites

This study explored the functional attributes of fiber composites filled with plant banana fibre and coconut shells. There are so many plant fibers like banana fiber, bamboo fiber, coconut sheath and sisal fiber which are typically dumped aside as waste material have a big capability of using it as substitutes as a reinforcement material. Epoxy is also employed as matrices. The fibres are processed in sodium hydroxide and the composites are made by manual layout. The manufactured samples shall be tested for various mechanical properties in compliance with the ASTM requirements. The scope for the use of such a plant fiber composites in numerous vehicle industries is analysed. Such composites material could be employed to create different automotive components. The use of these plant fibers entails lowers costs and energy needs. Since plant fibre composites are much less bulky, they can also be utilized to manufacture lighter parts. In this investigation mechanical characterization of banana fiber and coconut sheath has been carried out and comparative study has been performed.

Effect of tool material on thrust force and delamination in the drilling of coconut leaf sheath fibre reinforced polymer composites

Natural fibre reinforced composites are perceived as preferred material over engineering fibre composites due to their intrinsic properties. Nowadays development of low-cost composites with preferable good mechanical properties is one of the major issues in research areas. The machining of composite materials faces various issues, for example, delamination factor and cutting variables. This paper presents the investigation of factors that impact the thrust force and delamination in the drilling of coconut leaf sheath reinforced composites by considering Taguchi's and ANOVA techniques. The material used for fabricating the composite materials are coconut leaf sheath and phenol formaldehyde resin. It is fabricated by using a hand layup method with 6 mm thickness. An orthogonal array of L9 is implemented and experiments were conducted. The test results have demonstrated that the rate of feed is seen to be more contributing to delamination and thrust force than cutting speed.

Tribological properties of areca sheath fiber composites

Polymer composites with different fiber fractions 0, 12, 24, 36 and 48 wt% of short areca sheath fibers were prepared and the relative effect on its physical, mechanical and tribological characteristics were examined. From the investigation it is found that the theoretical or the measured density decreases with increase in the fiber concentration. On the other hand, void fraction increases with the increase in the fiber concentration. An optimum values of investigated mechanical properties such as the hardness (72.56 HRB), Young’s modulus (1.98 GPa), and the Impact strength (4.724 J) have been observed with the increase in fibre fraction. Furthermore, the flexural strength, flexural modulus and the tensile strength get decreased with the increase in the fibre fraction. The abrasion test is conducted to study the tribological behavior of the specimens implementing Taguchi orthogonal array (L25) and the variance analyzing techniques. The tribological study has shown that 36 wt% specimen experiences minimal wear rate at a higher sliding velocity of 1.2 m/s. The wear rate of all the composites is fairly minimal at higher sliding velocities and during the application of lesser normal load. The coefficient of friction (COF) increases up to a distinct value relating to sliding velocity and normal load. Further rise in the sliding velocity or normal load will result in the drop of COF.

Effect of fiber fraction on the physical and mechanical properties of short areca sheath fiber reinforced polymer composite

The fiber fraction in a composite will have a significant influence on its behavioural aspects and is reported in the current study. With different fiber fractions (0, 12, 24, 36 and 48 wt%) of the areca sheath fiber reinforcing agent, composite specimens were prepared and its physical and mechanical properties were examined. The measured density of the neat epoxy to the higher fiber fraction composite specimen (48 wt%) varies from 1.147 to 0.9524 g/cm 3 , from which it is evident that the density decreases with increase in the fiber concentration. On the other hand, void fraction for a neat epoxy is 0.26% which increases with the increase in the fiber concentration and is 6.14% for the 48 wt% fiber loaded specimen. An optimum values of investigated mechanical properties such as the hardness (72.56 HRB), Young’s modulus (1.98 GPa), and the Impact strength (4.724 J) have been observed with the increase in fibre fraction. The flexural strength for the neat epoxy is 46.28 MPa starts decreasing with the inclusion of fibers and reaches 12.05 MPa at a higher fraction of 48 wt%. The similar declining behaviour may be observed for the flexural modulus of 0.26 GPa and tensile strength of 14.02 MPa at high fiber fraction.

Core–Sheath Fiber‐Based Wearable Strain Sensor with High Stretchability and Sensitivity for Detecting Human Motion

AbstractFiber‐based strain sensors are considered to be an important part of smart wearables due to their flexible performance, lightness, and easily processing into various structures. However, the low sensitivity of fiber‐based strain sensors has limited their real‐life applications for detecting human movements. In this work, a poly(styrene‐butadiene‐styrene) (SBS)/multi‐walled carbon nanotube (MWCNTs) core–sheath fiber (SSCCSF) strain sensor is fabricated via a simple and facile coaxial wet‐spinning method. The cross‐sectional morphology, the mechanical properties, and the electromechanical performance of the SSCCSFs are investigated. Scanning electron microcopy results show that SSCCSFs have a bean‐like cross‐section with SBS as the core and SBS/MWCNTs as the sheath. Electromechanical performance evaluation confirms that the SSCCSF show a high sensitivity in a broad working range (gauge factor = 25832.77 at 41.5% strain) and excellent durability (5000 cycles at 10% strain). Furthermore, the SSCCSF displays outstanding sensing performance for detecting large motions in human movements including hand joint bending (such as knuckles and wrists) and subtle motions in physiological activities, involved in swallowing behavior, breathing, and pulse beat. This study demonstrates the potential application of SSCCSFs for wearable electronics with activity monitoring sensors.