Fiber Size Distribution Research Articles

Influence of multimodal fiber distribution on the permeability of fibrous media

This article deals with the impact of fiber size distribution on the permeability of nonwoven fibrous media, a major issue in the general field of filtration. The conventional method to determine the permeability of nonwoven fibrous media involves equating complex fibrous media with structures composed of a single equivalent fiber diameter. Based on numerical simulations of flow through tridimensional structures with polymodal and polydisperse fiber size distributions, we proposed a new equivalent diameter. In conjunction with a packing density function, the approach is compared to experimental data and simulations available in the scientific literature and shows better permeability predictions than other existing models for a wide range of solid volume fractions (1 % to 20 %) and fiber diameters (1.5 µm to 30 µm). This predictive model of permeability is an essential step in developing a decision-making tool for the design of fibrous media.

Utilizing Flax Straw for Sustainable Paper Production: Delignification Methods, Structural Analysis, and Fiber Size Distribution Effects

This research explores the potential of agricultural waste, specifically flax straw, as a sustainable raw material for eco-friendly packaging materials. This study investigates a three-stage delignification process involving nitric acid, alkaline treatment, and organosolvent solutions. This method effectively removes lignin from the straw, resulting in high-quality technical pulp with 67.7% α-cellulose and a significantly reduced ash content (8.5%). X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were employed to characterize the treated flax straw. XRD analysis revealed changes in the cellulose structure, while TGA indicated enhanced thermal stability compared to untreated straw. Microscopic analysis of the pulp fibers shows a parallel and aligned arrangement, suggesting a high fiber content and a strong paper lattice. The particle size distribution of the ground pulp, influenced by fiber size, has implications for the packing density and mechanical properties of the final product. This study demonstrates the potential of agricultural waste as a sustainable source for packaging materials, contributing to the circular economy and waste reduction.

Impaired Upper Airway Muscle Function with Excessive or Deficient Dietary Intake of Selenium in Rats.

Obstructive sleep apnoea (OSA) involves impaired upper airway muscle function and is linked to several pathologies including systemic hypertension, daytime somnolence and cognitive decline. Selenium is an essential micronutrient that exerts many of its effects through selenoproteins. Evidence indicates that either deficient or excessive dietary selenium intake can result in impaired muscle function, termed nutritional myopathy. To investigate the effects of selenium on an upper airway muscle, the sternohyoid, rats were fed on diets containing deficient, normal (0.5 ppm sodium selenite) or excessive (5 ppm selenite) selenium for a period of two weeks. Sternohyoid contractile function was assessed ex vivo. Serum selenium levels and activity of the glutathione antioxidant system were determined by biochemical assays. The abundance of three key muscle selenoproteins (selenoproteins -N, -S and -W (SELENON, SELENOS and SELENOW)) in sternohyoid muscle were quantified by immunoblotting. Levels of these selenoproteins were also compared between rats exposed to chronic intermittent hypoxia, a model of OSA, and sham treated animals. Although having no detectable effect on selected organ masses and whole-body weight, either selenium-deficient or -excessive diets severely impaired sternohyoid contractile function. These changes did not involve altered fibre size distribution. These dietary interventions resulted in corresponding changes in serum selenium concentrations but did not alter the activity of glutathione-dependent antioxidant systems in sternohyoid muscle. Excess dietary selenium increased the abundance of SELENOW protein in sternohyoid muscles but had no effect on SELENON or SELENOS. In contrast, chronic intermittent hypoxia increased SELENON, decreased SELENOW and had no significant effect on SELENOS in sternohyoid muscle. These findings indicate that two-week exposure to selenium-deficient or -excessive diets drastically impaired upper airway muscle function. In the sternohyoid, SELENON, SELENOS and SELENOW proteins show distinct alterations in level following exposure to different dietary selenium intakes, or to chronic intermittent hypoxia. Understanding how alterations in Se and selenoproteins impact sternohyoid muscle function has the potential to be translated into new therapies for prevention or treatment of OSA.

Enabling low molecular weight electrospinning through binary solutions of polymer blends

The formation of nanofibrous membranes via electrospinning is typically restricted to high molecular weight polymers in an appropriate solvent, correlated with the necessary formation of polymer chain entanglements that are needed to achieve successful production of electrospun fibers. The present work extends the electrospinning of low molecular weight polymers by investigating the electrospinning of a binary solution system consisting of two different low molecular weight polymers, using as a model system polycaprolactone (PCL) and gelatin in different ratios. The viscosities of the polymer solutions were characterized as a proxy for polymer chain entanglement and the resulting fibers were morphologically characterized by SEM imaging and further assessed water contact angle and molecular composition to determine the impact and homogeneity of the binary mixtures. We found that unitary solutions of either PCL or gelatin failed to generate proper fibers despite indications of chain entanglement. In contrast, binary solutions of low molecular weight PCL and gelatin generated different fiber quality and size distributions, depending on the ratio used, with direct correlations between fiber properties and the PCL:Gelatin ratio. It was discovered that the ratio of PCL to gelation was most predictive for successful fiber generation, with effective electrospinning occurring only for a define intermediate range of high blend ratios while both low and high blended binary solutions resulted in poor fiber production. Our study confirmed that this behavior was independent from absolute polymer concentration, indicating a unique interaction between these binary species which exists only under specific ratio concentrations and indicates promising new avenues to process low molecular weight polymers solutions.

Numerical investigation of roping in multi-die meltblowing

This work aims at conducting a numerical investigation of the effect of the inter-die distance on the probability of roping during meltblowing. The results are qualitatively compared with the experimental data obtained by the present group in studies of roping in a model situation of solution blowing. The effectiveness of nonwoven products as filter membranes and others depends on the fiber size and geometrical fiber distributions in fiber mats. Jet roping in meltblowing results in a distortion of the laydown structure, which is detrimental to the product's efficiency. A quasi one-dimensional model is utilized here to predict the probability of jet–jet intersection in flight leading to roping, which was observed experimentally in the prior works of this group. The results of the present work are expected to be helpful in optimizing operating parameters to minimize roping in meltblown products.

Amelioration of Morphological Pathology in Cardiac, Respiratory, and Skeletal Muscles Following Intraosseous Administration of Human Dystrophin Expressing Chimeric (DEC) Cells in Duchenne Muscular Dystrophy Model.

Duchenne Muscular Dystrophy (DMD) is a lethal disease caused by mutation in the dystrophin gene. Currently there is no cure for DMD. We introduced a novel human Dystrophin Expressing Chimeric (DEC) cell therapy of myoblast origin and confirmed the safety and efficacy of DEC in the mdx mouse models of DMD. In this study, we assessed histological and morphological changes in the cardiac, diaphragm, and gastrocnemius muscles of the mdx/scid mice after the transplantation of human DEC therapy via the systemic-intraosseous route. The efficacy of different DEC doses was evaluated at 90 days (0.5 × 106 and 1 × 106 DEC cells) and 180 days (1 × 106 and 5 × 106 DEC cells) after administration. The evaluation of Hematoxylin & Eosin (H&E)-stained sectional slices of cardiac, diaphragm, and gastrocnemius muscles included assessment of muscle fiber size by minimal Feret's diameter method using ImageJ software. The overall improvement in muscle morphology was observed in DMD-affected target muscles in both studies, as evidenced by a shift in fiber size distribution toward the wild type (WT) phenotype and by an increase in the mean Feret's diameter compared to the vehicle-injected controls. These findings confirm the long-term efficacy of human DEC therapy in the improvement of overall morphological pathology in the muscles affected by DMD and introduce DEC as a novel therapeutic approach for DMD patients.

Coaxial electrospinning of polycaprolactone – A design of experiments approach

Coaxial electrospinning is a commonly used technique in pharmaceutical sciences that allows producing polymeric nano- or microfibers with core-shell structure. In addition to process parameters such as voltage and flow rate of the polymer solutions, the properties of such fibers are influenced by solution properties including the total polymer concentration and the polymer ratio between fiber core and shell. As these parameters are typically changed empirically during development of electrospinning methods, there is a lack of structured studies that determine the optimal settings for the production of homogeneous, mechanically stable fibers. Therefore, we used a design of experiments approach to systematically address the coaxial electrospinning process of polycaprolactone, a polymer for biomaterials applied to the skin, for instance in the form of patches for wound healing or the treatment of skin cancer. We set out to investigate the influence of different process parameters on the fiber morphology (diameter and size distribution) as well as their mechanical properties as these properties are decisive determinants for handling and pharmaceutical efficacy of such patches. The investigated process parameters were the polymer concentration in the electrospinning solution and the ratio of polymer between fiber core and shell. We additionally investigated the impact of the presence of the model drug hydrocortisone in the fiber core on the electrospinning outcome and the drug release. The experiments revealed that the fiber diameter increases with increasing total polymer concentration, correlating with a narrower fiber size distribution. In addition, our results show that a higher ratio of polymer content in core and shell leads to more mechanically stable fibers (higher tensile strength, higher Young’s modulus). Taken together, the results obtained in this study contribute to a better understanding of the electrospinning process of polycaprolactone.

Bacteria Pseudomonas taiwanensis as a decomposing agent of peat fiber

Efforts are needed to accelerate the decomposition of peat fiber to reduce the fiber content through bioaugmentation using Pseudomonas taiwanensis bacteria so that it can reduce the high-water content of peat fiber. The research aimed to determine the effect of adding Pseudomonas taiwanensis bacteria on the decomposition of peat fiber. This research is a laboratory experimental research. The research sampling location was in Bereng Bengkel Village, Palangkaraya. The parameters observed included fiber content, fiber size distribution, and peat fiber decomposition speed following the Peat Testing Manual. The research instrument was an observation sheet for fiber content, size distribution, and peat fiber decomposition speed. Research data was analyzed using descriptive statistical analysis. The results showed that adding 15% Pseudomonas taiwanensis bacteria with a curing period of 28 days in fibrous peat resulted in the highest reduction in fiber content, from the initial condition of 61.14% to 12.33%. This variation also shows a decrease in coarse and medium fiber content and a significant increase in fine fiber content. The decomposition rate for this variation shows good consistency. The conclusion was that adding 15% Pseudomonas taiwanensis bacteria with a curing period of 28 days showed optimal results in accelerating the decomposition of peat fiber through the bioaugmentation method.

Fabrication of Zein/PVA Fibre Blends: Optimizing Concentration and Applied Voltage

Abstract: The fabrication of polymer fibre blends has gained much attention for the development of innovative nanomaterials. Polymer fibre blends are nanomaterials with different functionalities and properties such as a sizeable surface-to-area ratio, high porosity, flexibility, and stability. The focus of this study was to produce zein/PVA fibre blends using the electrospinning technique and varying parameters such as concentration and applied voltage. The two parameters are key driving factors for the production of fibres. Zein as a natural polymer has challenges in developing fibre materials which require artificial polymer like PVA to create a good blending mixture for electrospinning. Methods: The zein/PVA nanofibre blends were fabricated using the electrospinning technique. The FE-SEM (Leo, Zeiss) was used to study the surface morphologies of the zein/PVA nanofibers blends. The optical properties of the nanofibre blends were determined using the UV-vis spectrophotometer and the chemical structure and composition of zein/PVA nanofibers blends were studied using Thermo Scientific Nicolet iS50-FTIR spectrometer, universal ATR with the diamond detector. Results: The SEM images showed smooth zein/PVA ribbon-like nanofibre blends of 90/10, 80/20, 70/30, 60/40, and 50/50. SEM images of zein/PVA (80/20) electrospun at 25 kV were obtained to be the maximum fibre yield due to zein/PVA compatibility, increased conductivity, and enhanced fibre formation. The optical properties (absorption spectroscopy) suggested that the zein/PVA (80/20) fibre blend was miscible, and the FTIR spectra confirmed their functional groups. Therefore, the characterization results showed that the polymer blended solutions concentration and applied voltage increment affected fibre size distribution and morphology. Conclusion: Optimizing concentration and applied voltage successfully produced smooth, uniform bead-free zein/PVA fibre blends as parameters are increased.

Fiber Stiffness: An Essential Parameter of the Effectiveness of Fiber-Based Lost Circulation Materials—A CFD-DEM Numerical Investigation

Summary Fiber materials have become an attractive choice for lost circulation material (LCM) applications recently. While there has been significant attention on the size, aspect ratio, and size distribution of fibers, the stiffness or basically the effect of their deformability on the sealing capability has not been studied rigorously. Experimental evaluations of fibers with different material properties could be a cumbersome, time-consuming, and expensive process. Most laboratory studies are limited to one or just a few different types of materials. Hence, a novel two-way-coupled computational fluid dynamics and discrete element method (CFD-DEM)-based numerical model is used to overcome this limitation and to simulate motion, collision, deformation, and finally entanglement of individual LCM fibers moving with the fluid along a fracture. Fiber stiffness is determined by the Young’s modulus, the fiber diameter, and the fiber length. Therefore, we investigate this effect in a parametric study with a focus on the impact of the length, diameter, and Young’s modulus of the fiber on their sealing capability. An in-depth analysis reveals that the bridging mechanism for fiber LCM changes with the stiffness of the fiber. Two distinct bridging mechanisms dependent on the fiber stiffness for fiber LCMs are identified. Based on the simulation results, we developed a conceptual model for the different mechanisms that fibers use for bridge initiation. It is also observed that in determining LCM effectiveness, both the fiber stiffness and the fiber dimensions go hand in hand. Stiff fibers were associated with greater maximum plugging pressures (MPPs). The effect of using a mix of soft and stiff fibers on fracture plugging effectiveness has been evaluated. The fiber LCM effectiveness as a consequence of the bending stiffness on bridging larger fractures is also investigated. Key Terms and Phrases lost circulation materials, fibers, fracture sealing, bridging mechanism

Effect of Polybutylene Succinate Additive in Polylactic Acid Blend Fibers via a Melt-Blown Process.

This work aimed to study the influence of the polybutylene succinate (PBS) content on the physical, thermal, mechanical, and chemical properties of the obtained polylactic acid (PLA)/PBS composite fibers. PLA/PBS blend fibers were prepared by a simple melt-blown process capable of yielding nanofibers. Morphological analysis revealed that the fiber size was irregular and discontinuous in length. Including PBS affected the fiber size distribution, and the fibers had a smoother surface with increased amounts of added PBS. Differential scanning calorimetry analysis (DSC) revealed that the crystallization temperature of the PLA sheet (105.8 °C) was decreased with increasing PBS addition levels down to 91.7 °C at 10 wt.% PBS. This suggests that the addition of PBS may affect PLA crystallization, which is consistent with the X-ray diffraction analysis that revealed that the crystallinity of PLA (19.2%) was increased with increasing PBS addition up to 28.1% at 10 wt% PBS. Moreover, adding PBS increased the tensile properties while the % elongation at break was significantly decreased.

In situ forming biomaterials as muscle void fillers for the provisional treatment of volumetric muscle loss injuries.

Volumetric muscle loss (VML) represents a devastating extremity injury which leads to chronic functional deficits and disability and is unrecoverable through normal healing pathways. When left untreated, the VML pathophysiology creates many challenges towards successful treatment, such as altered residual muscle architecture, excessive fibrosis, and contracture(s). As such, innovative approaches and technologies are needed to prevent or reverse these adverse sequelae. Development of a rationally designed biomaterial technology which is intended to be acutely placed within a VML defect - i.e., to serve as a muscle void filler (MVF) by maintaining the VML defect - could address this clinical unmet need by preventing these adverse sequelae as well as enabling multi-staged treatment approaches. To that end, three biomaterials were evaluated for their ability to serve as a provisional MVF treatment intended to stabilize a VML defect in a rat model for an extended period (28 days): polyvinyl alcohol (PVA), hyaluronic acid and polyethylene glycol combination (HA+PEG), and silicone, a clinically used soft tissue void filler. HA+PEG biomaterial showed signs of deformation, while both PVA and silicone did not. There were no differences between treatment groups for their effects on adjacent muscle fiber count and size distribution. Not surprisingly, silicone elicited robust fibrotic response resulting in a fibrotic barrier with a large infiltration of macrophages, a response not seen with either the PVA or HA+PEG. Taken together, PVA was found to be the best material to be used as a provisional MVF for maintaining VML defect volume while minimizing adverse effects on the surrounding muscle.

Endurance Exercise-Induced Fgf21 Promotes Skeletal Muscle Fiber Conversion through TGF-β1 and p38 MAPK Signaling Pathway.

Fgf21 has been identified as playing a regulatory role in muscle growth and function. Although the mechanisms through which endurance training regulates skeletal muscle have been widely studied, the contribution of Fgf21 remains poorly understood. Here, muscle size and function were measured, and markers of fiber type were evaluated using immunohistochemistry, immunoblots, or qPCR in endurance-exercise-trained wild-type and Fgf21 KO mice. We also investigated Fgf21-induced fiber conversion in C2C12 cells, which were incubated with lentivirus and/or pathway inhibitors. We found that endurance exercise training enhanced the Fgf21 levels of liver and GAS muscle and exercise capacity and decreased the distribution of skeletal muscle fiber size, and fast-twitch fibers were observed converting to slow-twitch fibers in the GAS muscle of mice. Fgf21 promoted the markers of fiber-type transition and eMyHC-positive myotubes by inhibiting the TGF-β1 signaling axis and activating the p38 MAPK signaling pathway without apparent crosstalk. Our findings suggest that the transformation and function of skeletal muscle fiber types in response to endurance training could be mediated by Fgf21 and its downstream signaling pathways. Our results illuminate the mechanisms of Fgf21 in endurance-exercise-induced fiber-type conversion and suggest a potential use of Fgf21 in improving muscle health and combating fatigue.

Deletion of Nmnat1 in Skeletal Muscle Leads to the Reduction of NAD+ Levels but Has No Impact on Skeletal Muscle Morphology and Fiber Types.

Nicotinamide adenine dinucleotide (NAD+) is a coenzyme that mediates many redox reactions in energy metabolism. NAD+ is also a substrate for ADP-ribosylation and deacetylation by poly (ADP-ribose) polymerase and sirtuin, respectively. Nicotinamide mononucleotide adenylyltransferase 1 (Nmnat1) is a NAD+ biosynthesizing enzyme found in the nucleus. Recent research has shown that the maintaining NAD+ levels is critical for sustaining muscle functions both in physiological and pathological conditions. However, the role of Nmnat1 in skeletal muscle remains unexplored. In this study, we generated skeletal muscle-specific Nmnat1 knockout (M-Nmnat1 KO) mice and investigated its role in skeletal muscle. We found that NAD+ levels were significantly lower in the skeletal muscle of M-Nmnat1 KO mice than in control mice. M-Nmnat1 KO mice, in contrast, had similar body weight and normal muscle histology. Furthermore, the distribution of muscle fiber size and gene expressions of muscle fiber type gene expression were comparable in M-Nmnat1 KO and control mice. Finally, we investigated the role of Nmnat1 in muscle regeneration using cardiotoxin-induced muscle injury model, but muscle regeneration appeared almost normal in M-Nmnat1 KO mice. These findings imply that Nmnat1 has a redundancy in the pathophysiology of skeletal muscle.

Pressure Drop Dynamics during Filtration of Mixture Aerosol Containing Water, Oil, and Soot Particles on Nonwoven Filters.

The pressure drop dynamics during the filtration of three-component mixture aerosols are investigated and compared with two and single-component aerosols. The main area of interest is the effect of the addition of a small quantity of liquid (oil) and solid (soot) particles during the filtration of aerosol containing water mist. In addition, calculations of the change in filter mass during oil aerosol filtration have been carried out and compared with the experimental results. The new, improved filtration efficiency model takes into account a better coefficient fitting in the filtration mechanism equations. The limitations in the change in fibre diameter and packing density resulting from the filter loading have been implemented in the model. Additionally, the calculation model employs the fibre size distribution representation via multiple average fibre diameters. The changes in fibre diameter are dependent on each fibre's calculated filtration efficiency. The improved filtration model has been utilised to predict the mass change of the filters during the filtration of pure and mixture aerosols. The pressure drop calculation model based on changes in filter mass has been formulated. The model is then utilised to calculate pressure drop changes resulting from the filtration of the oil aerosol and water and oil mixture aerosol.

Stabilized Electrospun Polyacrylonitrile Fibers for Advancements in Clean Air Technology

Particulate matter air pollution and volatile organic compounds released into the air from the incomplete combustion of fossil fuels and wildfires creates significant damage to human health and the environment. Advances in air filtration and purification technology are needed to mitigate aerosol hazards. This article details an effort to explore the potential benefits of new materials and methods for the production of nonwoven air filtration media through electrospinning and stabilizing polyacrylonitrile fibers. The investigated production methods include electrospinning fibrous matting onto a stainless steel wire mesh and stabilizing the nonwoven media in a chamber furnace. The media is then tested for air filtration penetration and airflow resistance, and the fiber size distribution is measured using scanning electron microscopy. The experimental results show that the electrospun media approaches the performance criteria for airflow resistance and particle capture efficiency of high-efficiency particulate air (HEPA) filter media. Furthermore, performance estimations for electrospun media of increased thickness and for a decreased filtration velocity show potential to exceed the HEPA media resistance and efficiency criteria. Thus, it is suggested that electrospun and stabilized nonwoven fibrous media are candidates as alternatives to traditionally manufactured HEPA media and may potentially benefit modern air filtration technology and reduce hazards associated with particulate matter. Additionally, the authors recommend future exploration into the carbonization and activation of electrospun filter media for the adsorption and mitigation of volatile organic compounds as a secondary benefit, while maintaining high efficiency and low airflow resistance in the removal of particulate matter from aerosol streams.

The effect of nozzle spacing on the electric field and fiber size distribution in a multi‐nozzle electrospinning system

AbstractThe present study investigates the characteristics of nanofiber uniformity in a multi‐nozzle electrospinning system widely used to prepare nanofiber matrix. The effect of nozzle spacing on the electric field and nanofiber diameter uniformity is analyzed using a four‐nozzle electrospinning system. The electric field distribution at the nozzle tip at different nozzle spacings is simulated numerically using COMSOL Multiphysics 5.6. Simulation results find that as nozzle spacings increase from 1 to 5 cm, the average electric field intensity at 1 mm from the tip of four nozzles increases from 32.46 to 40.08 kV/cm. Variations of electric field intensity at a given spacing decrease from 11% to 3.2% for spacings of 1 to 5 cm. Corresponding experiments are conducted with a gelatin solution. As the nozzle spacing increases, the four nozzles produce nanofibers with diameters of 88–508 nm, 112–498 nm, and 90–418 nm. Nanofiber diameter uniformity increases, and the average diameter decreases from 268 to 222 nm. In addition, the effect that changes in voltages and nozzle‐to‐collector distances have on fiber diameter is also studied. The experiments show that nanofiber diameter decreased as voltage increased and increased as nozzle‐to‐collector distance increased.

Direct Fabrication of Functional Shapes on 3D Surfaces Using Electrospinning.

In this work, we demonstrate the ability to simultaneously pattern fibers and fabricate functional 2D and 3D shapes (e.g., letters, mask-like structures with nose bridges and ear loops, aprons, hoods) using a single step electrospinning process. Using 2D and 3D mesh templates, electrospun fibers were preferentially attracted to the metal protrusions relative to the voids so that the pattern of the electrospun mat mimicked the woven mesh macroscopically. On a microscopic scale, the electrostatic lensing effect decreased fiber diameter and narrowed the fiber size distribution, e.g., the coefficient of variation of the fiber diameter for sample collected on a 0.6 mm mesh was 14% compared to 55% for the sample collected on foil). Functionally, the mesh did not affect the wettability of the fiber mats. Notably, the fiber patterning increased the rigidity of the fiber mat. There was a 2-fold increase in flexural rigidity using the 0.6 mm mesh compared to the sample collected on foil. Overall, we anticipate this approach will be a versatile tool for design and fabrication of 2D and 3D patterns with potential applications in personalized wound care and surgical meshes.

Metabolic dysregulation and decreased capillarization in skeletal muscles of male adolescent offspring rats exposed to gestational intermittent hypoxia.

Gestational intermittent hypoxia (IH) is a hallmark of obstructive sleep apnea that occurs frequently during pregnancy, and effects caused by this environmental change during pregnancy may be transmitted to the offspring. In this study, we aimed to clarify the effects of IH in pregnant rats on the skeletal muscle of adolescent offspring rats. Mother rats underwent IH from gestation day 7-21, and their 5-weeks-old male offspring were analyzed. All male offspring rats were born and raised under normoxia conditions. Although no general growth retardation was observed, we found that exposure to gestational IH reduces endurance running capacity of adolescent offspring rats. Both a respiratory muscle (diaphragm; DIA) and a limb muscle (tibialis anterior; TA) showed no histological abnormalities, including fiber size and fiber type distribution. To identify the possible mechanism underlying the reduced running capacity, regulatory factors associated with energy metabolism were analyzed in different parts of skeletal muscles. Compared with rats born under conditions of gestational normoxia, gestational IH offspring rats showed significantly lower expression of genes associated with glucose and lipid metabolism, and lower protein levels of phosphorylated AMPK and AKT. Furthermore, gene expression of adiponectin receptors one and two was significantly decreased in the DIA and TA muscles. In addition, the DIA muscle from adolescent rats had significantly decreased capillary density as a result of gestational IH. However, these changes were not observed in a sucking muscle (geniohyoid) and a masticating muscle (masseter) of these rats. These results suggest that respiratory and limb muscles are vulnerable to gestational IH, which induces altered energy metabolism with decreased aerobic motor function. These changes were partially owing to the decreased expression of adiponectin receptors and decreased capillary density in adolescent offspring rats.

Hop natural fiber-reinforced poly(butylene succinate-co-butylene adipate) (PBSA) biodegradable plastics: effect of fiber length on the performance of biocomposites

Three sizes of hop fibers were tested at 30 wt% in PBSA biocomposites for material performance. Fibre length and size distribution were found to be key factors on mechanical and thermal properties of natural fiber-reinforced composites.