Loose Fibers Research Articles

Green utilization of sorghum straw by coupled hydrothermal pretreatment and cellulase hydrolysis for bacillomycin D production under fed-batch mode

The present work explored the coupled hydrothermal pretreatment and cellulase hydrolysis (HPCH) for production of bacillomycin D from sorghum straws by Bacillus subtilis NS-174. The results indicated that HPCH treated sorghum straws had weaker absorption, heavier mass loss and higher crystallinity, and displayed loose and destructive fiber structures. Degradation of hemicellulose and lignin contributhed to yielding glucose and 68.94g/L of glucose was obtained in HPCH treated hydrolysate. High level of glucose in pretreated sorghum straw hydrolysate was helpful for improving bacillomycin D production. When performed by 3rd round (feeding at 144h) fed-batch fermentation, bacillomycin D production and production rate were obtained to be 2351.07mg/L and 113.36mg/L.h in B. subtilis NS-174, respectively.

An organic-inorganic dual network built in fast-growing wood veneers to improve the flame retardant and mechanical properties of plywood

Fast-growing wood is widely used in plywood production due to its short growth cycle and low cost. However, its loose fiber structure, inferior material quality, and high flammability significantly limit the application range of plywood products and hinder high-value utilization. This paper reports a simple method for modifying fast-growing wood veneers. We modified phenolic resin with Mg(OH)₂@nano-silica composite particles and impregnated it into the veneers, constructing an organic-inorganic hybrid dual-network structure on both the surface and interior of the veneers. The plywood prepared from the modified veneers exhibited a bending strength of 115.6 MPa, a modulus of elasticity of 9.7 GPa, and a wet shear strength of 2.1 MPa, representing increases of 86.1%, 47.0%, and 90.9%, respectively, compared to plywood made from unmodified veneers. Additionally, the peak heat release rate decreased by 15.3%, and the ignition time was extended to 26 seconds. The uniformly distributed inorganic network effectively mitigated stress concentration and, together with the phenolic resin, formed an efficient thermal insulation layer, enhancing the flame retardancy of the material. This study offers a simple and effective treatment method for reinforcing fast-growing wood veneers, promoting the use of fast-growing wood in high-performance applications.

Mitigation of plastic shrinkage cracking with natural fibers - kenaf, abaca, coir, jute and sisal

In this study, a number of different fibers - namely kenaf, jute, abaca, coir and sisal - were investigated as natural alternatives to polypropylene (PP) fibers for reducing plastic shrinkage cracking. The risk of plastic shrinkage cracking of mortars with water-to-cement ratio 0.5 containing either 0.6 or 0.9 kg/m3 of natural fibers was assessed according to the ASTM C1579-21 standard and compared with plain mortars and mortars with PP fibers. The water absorption of the natural fibers was low enough that (at the employed dosages) the effect on the workability and on other fresh properties was small. The natural fibers also had no measurable influence on cement hydration in the examined mortars, as revealed by isothermal calorimetry.The best performance in reducing the width of plastic shrinkage cracks was shown by kenaf and jute fibers at the dosage of 0.6 kg/m3, which outperformed even a higher dosage of PP fibers (0.9 kg/m3). Kenaf fibers in pellets, which are advantageous for dosing and mixing, performed similarly as loose fibers. The distribution of both loose and pelletized kenaf fibers in the mortars was studied by X-ray tomography, showing no substantial difference between the two ways of delivering the fibers.

Thermal conductivity assessment of cotton fibers from apparel recycling for building insulation

The impressive growth of the clothing market in the last decades comes along with an increase in the textile waste, nowadays mostly incinerated or landfilled. To improve the circularity of the sector, the possibility to recycle the textile waste into thermal insulation products for the building envelope has started to emerge. While the scientific literature agrees that the thermal conductivity of products based on textile waste is comparable to conventional thermal insulators, very few studies provide a comprehensive characterization of their heat transfer behavior in terms of the relevant parameters. This study focuses on post-consume cotton in the form of loose fibers with density 30, 50 and 70 kg/m3. By exploiting complementary experimental techniques, it is found that the effective thermal conductivity ranges between 0.0381 W/(m∙K) (ρ = 30 kg/m3, T = 10 °C, RH = 17 %) and 0.0546 W/(m∙K) (ρ = 50 kg/m3, T = 30 °C, RH = 80 %). The conductivity of the loose cotton fibers is predominantly sensitive to temperature and relative humidity, while the influence of density and the vertical/horizontal orientation appear less significant. These results highlight the complexity of the characterization of the thermal performance of such fibrous materials and the need to perform tests under fully controlled environmental conditions. Moreover, they are key for an accurate prediction of the performance of such insulating materials in real building operation, possibly achieved through dynamic energy simulations including heat and vapor transfer and modelling the conductivity variation with temperature and moisture.

Effects of chronic intermittent hypoxia and reoxygenation on insulin resistance and skeletal muscle miR-27a-3p/PPARγ/IRS1/PI3K/AKT expressions in rats

To investigate the effects of chronic intermittent hypoxia (CIH) and reoxygenation on insulin resistance (IR) and expressions of miR-27a-3p/PPARγ/IRS1/PI3K/AKT in rat skeletal muscle. GEO database was used for screening the differentially expressed miRNAs in CIH, and their target genes were subjected to GO and KEGG enrichment analysis followed by construction of the miRNA-mRNA-pathway regulatory network using Cytoscape. In the animal experiment, 48 male SD rats were randomly divided into normoxia group and CIH group (8 weeks of CIH followed by 4 weeks of normoxic recovery). Blood and skeletal muscle samples were collected at baseline, 8 weeks, and 12 weeks to evaluate the changes in fasting blood glucose (FBG) and fasting insulin (FINS) levels and muscular pathology. RT-qPCR and Western blotting were used to detect the changes in the expressions of miR-27a-3p, PPARγ, GLUT4, IRS1, p-IRS1, PI3K, p-AKT and AKT in the muscular tissues. No muscular miRNA datasets for CIH were available in GEO database, from which only a kidney-related dataset (GSE202480) was obtained, based on which a total of 165 differentially expressed miRNAs were identified. GO/KEGG analysis suggested that these miRNAs were involved in muscular regulation and insulin signaling. The miRNA-mRNA-pathway network highlighted miR-27a-3p as a crucial regulator in the PPAR and PI3K/AKT pathway. In the animal experiment, the rats subjected to CIH for 8 weeks showed significantly increased FBG, FINS, HOMA-IR, and PPARγ levels, loose muscle fiber arrangement, decreased cross-sectional area of the muscle fibers, and lowered expressions of miR-27a-3p, p-IRS1/IRS1, PI3K, and p-AKT/AKT in the skeletal muscles. CIH increases IR, causes skeletal muscle pathology, downregulates miR-27a-3p expression, upregulates PPARγ expression, and inhibits IRS1/PI3K/AKT insulin signaling in the skeletal muscles of rats, and these changes can be reversed by reoxygenation. MiR-27a-3p may participate in CIH-induced IR by modulating the PPAR γ/IRS1/PI3K/AKT signaling pathway.

Carbon Fiber-Mediated Electrospinning Scaffolds Can Conduct Electricity for Repairing Defective Tendon.

Partial or complete rupture of the tendon can damage the collagen structure, resulting in the disruption of the electrical signal pathway. It is a great challenge to reconstruct the original electrical signal pathway of the tendon and promote the regeneration and functional recovery of defective tendon. In this study, carbon fiber-mediated electrospinning scaffolds were fabricated by wrapping conductive, high-strength, loose single-bundle carbon fibers with nanofiber membranes. Due to the presence of nanofiber membranes, the maximum tensile force of the scaffolds was 2.4 times higher than that of carbon fibers, while providing excellent temporal and spatial prerequisites for tenocytes to adapt to electrical stimulation to accelerate proliferation and expression. The diameter of the carbon fiber monofilaments used in this study was 5.07 ± 1.20 μm, which matched the diameter of tendon collagen, allowing for quickly establishing the connection between the tendon tissue and the scaffold, and better promoting the recovery of the electrical signal pathway. In a rabbit Achilles tendon defect repair model, the carbon fiber-mediated electrospinning scaffold was almost filled with collagen fibers compared to a nonconductive polyethylene glycol terephthalate scaffold. Transcriptome sequencing revealed that fibromodulin and tenomodulin expression were upregulated, and their related proteoglycans and glycosaminoglycan binding proteins pathways were enhanced, which could regulate the TGF-β signaling pathway and optimize the extracellular matrix assembly, thus promoting tendon repair. Therefore, the scaffold in this study makes up for the shortage of conductive scaffolds for repairing tendon defects, revealing the potential impact of conductivity on the signaling pathway of tendon repair and providing a new approach for future clinical studies.

The role of carboxyl and cationic groups in low-level cationised cellulose fibres investigated by zeta potential and sorption studies

The anionic nature of both cellulose fibres and reactive dyes prevents substantial exhaustion of dye from the dyebath, which is at neutral pH before alkali is added to initiate dye fixation. Conventionally, salt is added to minimize the electrostatic repulsions that interfere with dye sorption, but that increases salt loads in effluents. An alternative is to affix cationic agents on the cellulose to overcome the inherent anionic charge, but that has generally been observed to result in uneven dye sorption. The focus of investigations in this work is to examine the influence of the ratio of charges on cellulose (of affixed cationic charges to inherent anionic charges) on the extents and evenness of dye sorption. The cationisation agent 3-chloro-2-hydroxypropyl-N,N,N-trimethylammonium chloride (CHPTAC) was grafted on loose viscose fibres to yield 12 to 185 mmol kg−1 cationic group content on the fibre that exhibited an inherent carboxyl group content of 68 mmol kg−1. Three different dyes (of varying molecular sizes and anionic group content) were employed for examination of sorption profiles. The results from both zeta potential measurements and dye sorption profiles showed evidence of limited dye uptake until the cationic group content in fibres exceeded that of the inherent carboxyl groups. Thereafter, an uptick in dye sorption was observed, with dye sorption levels increasing with rise in degree of cationisation. There were differences between the dyes in their degrees of sorption, which appear correlated with their molecular sizes.

Unveiling the microstructural evolution and interaction mechanisms for twisted structures

Twisting plays an important role in fabricating twisted actuators and energy harvesters, which require excellent microstructural deformation and interaction properties between different layers. However, the cross-layer microstructural evolution and interaction mechanism of helical structures under twisting and stretching are still unclear. Herein, a multi-layer model is established to theoretically investigate the response of the filaments under twisting and stretching. The results quantitatively indicate that the filaments with a higher twist have more structural evolution and less elongation deformation in the tensile process, which contributes to the increase of ductility. The evolution of the helical angle is also verified by in-situ experiments and finite element simulations. Besides, a theoretical method is provided for investigating the mechanical behavior of anisotropic twisted fibers, and the contact pressure is also promoted to understand the twisting-induced densification. The interlayer extrusion reveals that appropriate stretching of twisted fiber is an effective way to densify the loose fibers, and it also provides the theoretical reason for twisting and stretching simultaneously when wringing out a wet towel. We believe that this work would shed light on the interaction mechanism of twisted filaments and provide mechanistic insights into the twisting design of multi-layer helical structures.

Synthesis of silsesquioxane-linked polyester with liquid crystalline backbone chain

A novel procedure for the synthesis of a 3D network polyester bearing silsesquioxane cores was executed to prepare the ternary silsesquioxane-linked copolyester BNH (BNH4 and BNH8) based on 4-acetoxy benzoic acid (ABA), 6-acetoxy-2-naphthoxylic acid (ANA), and a silsesquioxane-cored monomer (CSQ-AHA4 or CSQ-AHA8). The thermal data and phase behavior indicated that moderate crosslinking would reduce the stacking of the backbones, thereby enhancing the mobility of the backbone. However, greater crosslinking would limit the movement of the backbone, while the 3D cross-linked structure enhanced the structural stability of the phase region and the uniformity of the crystal size distribution. The loose fiber bundles showed that the participation of the 3D configuration and silsesquioxane increased the chain flexibility, and facilitated the formation of strong polyester ultrafine fibers. It was possible to improve the lateral mechanical properties of the oriented polyester materials, probably improving the mechanical properties aspect ratio of thin film materials.

New Composites Derived from the Natural Fiber Polymers of Discarded Date Palm Surface and Pineapple Leaf Fibers for Thermal Insulation and Sound Absorption.

New composites made of natural fiber polymers such as wasted date palm surface fiber (DPSF) and pineapple leaf fibers (PALFs) are developed in an attempt to lower the environmental impact worldwide and, at the same time, produce eco-friendly insulation materials. Composite samples of different compositions are obtained using wood adhesive as a binder. Seven samples are prepared: two for the loose natural polymers of PALF and DPSF, two for the composites bound by single materials of PALF and DPSF using wood adhesive as a binder, and three composites of both materials and the binder with different compositions. Sound absorption coefficients (SACs) are obtained for bound and hybrid composite samples for a wide range of frequencies. Flexural moment tests are determined for these composites. A thermogravimetric analysis test (TGA) and the moisture content are obtained for the natural polymers and composites. The results show that the average range of thermal conductivity coefficient is 0.042-0.06 W/(m K), 0.052-0.075 W/(m K), and 0.054-0.07 W/(m K) for the loose fiber polymers, bound composites, and hybrid composites, respectively. The bound composites of DPSF have a very good sound absorption coefficient (>0.5) for almost all frequencies greater than 300 Hz, followed by the hybrid composite ones for frequencies greater than 1000 Hz (SAC > 0.5). The loose fiber polymers of PALF are thermally stable up to 218 °C. Most bound and hybrid composites have a good flexure modulus (6.47-64.16 MPa) and flexure stress (0.43-1.67 Mpa). The loose fiber polymers and bound and hybrid composites have a low moisture content below 4%. These characteristics of the newly developed sustainable and biodegradable fiber polymers and their composites are considered promising thermal insulation and sound absorption materials in replacing synthetic and petrochemical insulation materials in buildings and other engineering applications.

Phase formation and unusual interstitial solid-solution strengthening behavior of (CoCrFeMnNi)Nx high-entropy ceramic films

High-entropy ceramic films (HECFs) have become promising industrial materials due to their excellent mechanical and functional properties. Achieving the precise design of HECFs has been a hot topic in recent years. Herein, the CoCrFeMnNi alloy, one of the most classic high-entropy systems, is chosen as the model to reveal the phase formation, growth, and properties of HECFs. Films were fabricated by magnetron sputtering at various N2-to-total (N2 + Ar) flow ratios (RN). Results show that the phase structure transformed from a semi-crystal phase to a single face-centered cubic (fcc) structure with increasing RN. Atomic migration ability affected by RN drives different growth processes, thereby constructing different microstructures, such as loose fiber structure and stacked particle structure. Moreover, the hardness exhibits a nonlinear relationship with interstitial solid solubility. Such unusual interstitial solid-solution strengthening behavior is attributed to the offset between solid-solution strengthening and grain boundary weakening as RN increases. A high hardness of 13.71 GPa and Young's modulus of 203.3 GPa are obtained in the (CoCrFeMnNi)Nx film deposited at RN = 20 %. This work not only explores an unusual interstitial solid-solution strengthening behavior, but also sheds light on the future HECFs design.

Research Progress of Reinforced Modification of Fast-Growing Wood

The public’s requirements for a high-quality residential environment and the general improvement in ecological safety awareness have made renewable resource wood and products more favored by furniture, construction and other industries. However, on the one hand, the supply of natural forests is extremely limited, and on the other hand, the materials of artificial forests have defects such as low surface strength and poor dimensional stability due to a loose fiber structure, which restricts their promotion as an alternative to high-quality wood. In this paper, based on the mechanism of wood reinforcement, several reinforcement techniques, such as impregnation, compaction and surface modification, which are widely used in industry, are briefly introduced. On this basis, the possibility of impregnation as a pretreatment method, surface modification and densification to enhance wood was prospected. It is expected to provide reference for improving the added value of plantation wood and alleviating the contradiction between wood supply and demand.

Sarcocystis spp.: histological examination and morphometry

The purpose of the research is localization and morphometry of sarcocysts in animals.Materials and methods. Samples of striated muscle tissue of cows and wild boars were studied to determine the infection intensity and prevalence and determine morphometric parameters of cysts. Pathological material was collected to 10 % buffered formalin solution. For histological examination, muscle tissue samples were taken from the abdominal wall and cardiac muscle. To process tissue samples, paraffin coating was used in semi-automatic equipment from Thermo Scientific. Histological specimens were stained with hematoxylin and eosin and by Mallouri. The specimen histoarchitecture was assessed using an Axio A1.0 microscope; photographs were taken with AxioVision.Results and discussion. The sarcocyst infection prevalence was 60% in cattle and 100% in the boars, with the infection intensity of 1-2 and 2-4 sarcocysts in one FOV, respectively. It was found that the cyst formed a capsule in infected boars with a thickness of 2.6±0.28 μm, while it was practically invisible in cattle, and grouped loose connective tissue fibers were observed around the cyst. The infection intensity can be assessed as low in the studied animals; however, even single parasite cysts entered the human body contribute to sarcocystosis.

Effect of recycled fibers and shredded intermediates variation on the mechanical properties and energy absorption of fiber‐reinforced composite panels

AbstractThe global composite industry generates large quantities of waste which mostly ends up in landfills due to a lack of established end‐use applications for multiple waste streams. The scrap from end‐of‐life (EoL) includes manufacturing waste such as dry chopped fiber tows, loose fibers, shredded fibers from fabric textile operations, cured/semi‐cured prepregs, and fully cured composite structure waste from aircraft, automobiles, wind blades, boats, and pressure vessels. In this work, different composite waste streams were reduced to shredded intermediates, followed by simple blending, and subjected to wet compression molding to produce composite panels. The panels/plaques were tested for mechanical properties (flexure and impact), fiber‐matrix wet‐out, and property bounds. It was found that wet‐compression molding was a viable and scale‐able approach to produce recycled panels from EoL composites shredded scrap. Furthermore, full‐scale size panels for use in truck bodies and intermodal shipping container flooring were manufactured and their impact resistance was tested using a drop weight impact test. They were tested both for high‐ and low‐velocity load. In the case of high‐velocity load, the average impact load was 14,673 N; the average absorbed energy was 101.6 J; the average elastic energy was 11.7 J and the impact resistance was 1065 J/m. In the case of the low‐velocity drop weight impact test, it was found that the average impact load was 7877.358 N; the average absorbed energy was 9.718 J; the average elastic energy was 9.14 J, and the impact resistance was 184.1 J/m. The shredded composite was shown to be a candidate material for the manufacture of truck bodies and intermodal containers’ flooring panels.Highlights By using shredded intermediates from different composite waste streams, it is possible to manufacture composite panels. Wet–compression process is an appropriate technique for manufacturing recycled fiber composite panels. Regardless of the source of scrap, the mechanical properties of the produced composite panels were improved. The recycling process technology can be transformed to commercial scale to produce full‐size transportation flooring panels. A product pathway is established in consideration of lower cost and improved recyclability.

Assessing the Validity of Analytical Equations for Offshore Power Cable Bending with Fixed and Loose Tube Fiber Strain Sensors

Assessing the Validity of Analytical Equations for Offshore Power Cable Bending with Fixed and Loose Tube Fiber Strain Sensors

Blow spinning mass production of melamine@polyacrylonitrile composite nanofibers with enhanced flame-retardant and strengths

To achieve the scalable production of high-performance melamine-based flame retardant nanofibers, solution blowing spinning technology was employed into the continuous spinning of melamine(MA)@polyacrylonitrile(PAN) composite fibers. Propelled by the compressed air current, spinnable MA@PAN solutions can be shaped into nanofiber with a high flow rate over 50 ​mL/h. Among different melamine-based materials, melamine phosphate (MPP) exhibited excellent solubility in the solution, exceeding 30 ​wt%, ensuring that the MPP@PAN nanofiber products demonstrated exceptionally robust flame-retardant performance. Furthermore, through fiber textile needle punching technology, loose fiber sponge can be organized into enhanced fiber blankets. These MPP@PAN nanofiber products exhibited outstanding flame retardant and thermal insulation properties, rendering them pivotal as the flame-retardant materials in extreme environments.

Comparison of the Eggshell and the Porcine Pericardium Membranes for Guided Tissue Regeneration Applications.

Guided bone regeneration is frequently used to reconstruct the alveolar bone to rehabilitate the mastication using dental implants. The purpose of this article is to research the properties of eggshell membrane (ESM) and its potential application in tissue engineering. The study focuses on the structural, mechanical, and histological characteristics of ESM extracted from Gallus domesticus eggs and to compare them to a commercially available porcine pericardium membrane (Jason® membrane, botiss biomaterials GmbH, Zossen, Germany). Thus, histology was performed on the ESM, and a comparison of the microstructure through scanning electron microscopy and atomic force microscopy (AFM) was conducted. Also, mechanical tensile strength was evaluated. Samples of ESM were prepared and treated with alcohol for fixation and disinfection. Histological analysis revealed that the ESM architecture is constituted out of loose collagen fibers. However, due to the random arrangement of collagen fibers within the membrane, it might not be an effective barrier and occlusive barrier. Comparative analyses were performed between the ESM and the AFM examinations and demonstrated differences in the surface topography and mechanical properties between the two membranes. The ESM exhibited rougher surfaces and weaker mechanical cohesion attributed to its glycoprotein content. The study concludes that while the ESM displays favorable biocompatibility and resorb ability, its non-uniform collagen arrangement limits its suitability as a guided bone regeneration membrane in the current non-crosslinked native form. Crosslinking techniques may enhance its properties for such applications. Further research is needed to explore modifications and processing methods that could leverage the ESM's unique properties for tissue engineering purposes.

Eco-Friendly Methods for Extraction and Modification of Cellulose: An Overview.

Cellulose is the most abundant renewable polymer on Earth and can be obtained from several different sources, such as trees, grass, or biomass residues. However, one of the issues is that not all the fractionation processes are eco-friendly and are essentially based on cooking the lignocellulose feedstock in a harsh chemical mixture, such as NaOH + Na2S, and water, to break loose fibers. In the last few years, new sustainable fractionation processes have been developed that enable the obtaining of cellulose fibers in a more eco-friendly way. As a raw material, cellulose's use is widely known and established in many areas. Additionally, its products/derivatives are recognized to have a far better environmental impact than fossil-based materials. Examples are textiles and packaging, where forest-based fibers may contribute to renewable and biodegradable substitutes for common synthetic materials and plastics. In this review, some of the main structural characteristics and properties of cellulose, recent green extraction methods/strategies, chemical modification, and applications of cellulose derivatives are discussed.

"Capsule drape wrap"-a new technology for iridoschisis management during phacoemulsification.

To introduce a new technique for iridoschisis management during phacoemulsification: "capsule drape wrap". "Capsule drape wrap" technique was used for an 80-year-old man with idiopathic iridoschisis in the right eye during phacoemulsification. The inserted flexible nylon iris hooks to hold anterior capsule in place, the margin of the anterior capsule could act as drape wrap, tracking the fibrillary iris strands firmly from free floating and stabilizing the capsular bags simultaneously. The eye with iridoschisis was successfully treated. Iris fibrils remained immobile during the procedure, and despite the severity of iridoschisis, there were no intraoperative complications such as tear of the iris, hyphema, iris prolapse, loss of mydriasis, or rupture of the posterior lens capsule during phacoemulsification. The best-corrected visual acuity was increased by 0.1 (logMAR) 6mo after the surgery. "Capsule drape wrap" for iridoschisis is easily manageable, prevents further disruption to the loose iris fibers and ensures the stability of capsule-iris complex simultaneously, consequently minimizing the risk of surgical complications in phacoemulsification.

Ovariectomy with simulated vaginal delivery to establish a rat model for pelvic organ prolapse

ABSTRACT The widespread prevalence of Pelvic Organ Prolapse (POP) and the paucity of ongoing treatments prompted us to develop a unique rat model combining ovariectomy and simulated vaginal delivery. We hypothesized that the tissue changes caused by low hormone levels and mechanical stretch could complement each other. Thus, the combined model can potentially mimic the collagen metabolism of vaginal wall tissue as well as mechanical stretch properties to complement disease progression in POP. Ovariectomy with sequential simulated vaginal delivery was performed on rats in the modeling group. Sham surgeries were performed as control. At 2, 4, and 12 weeks after modeling, the vaginal tissues of rats were evaluated by Masson’s trichrome staining, Picro-Sirius red staining, immunohistochemistry, western blotting, and uniaxial tensile tests. Compared to the control group, the vaginal tissues of the model rats showed an atrophic epithelial layer and loose collagen fibers. The smooth muscle fibers were ruptured, smaller in diameter, and disorganized. The ratio of collagen type I/III significantly increased, but the contents of both Collagen I and III decreased. The expression of metalloproteinases 2 and 9 in the tissues increased, and the expression of tissue inhibitors of metalloproteinases 1 and 2 decreased. The tangent modulus of the tissues was significantly increased in the model rats. We verified a novel method to establish a pelvic organ prolapse model in rats. This approach combined the advantages of low hormone levels and mechanical stretch effects.