Fiber Predominance Research Articles

Expiratory Muscles, Neglected No More.

Expiratory Muscles, Neglected No More.

Seasonal variation of microplastics density in Algerian surface waters (South-Western Mediterranean Sea)

Coastal waters worldwide are widely contaminated with various-size plastics, whose presence in aquatic ecosystems has been shown to produce a wide range of economic and social impacts and harmful effects on marine ecosystems. While microplastics have been reported from many regions of the Mediterranean Sea, very few data exist regarding microplastics concentration in Algerian waters. In this study, we used a Manta trawl (330 µm) at six sampling stations in Bou-Ismail Bay, Algeria (South-West Mediterranean Sea) in order to provide novel information about the occurrence and composition of microplastics along the Algerian coast. Sampling was performed seasonally at six different sampling stations in 2018, providing additional information about the spatio-temporal variability of microplastics concentrations at the sea surface. Microplastics were found in all collected samples, with highly variable concentrations of 0.95, 0.88, 1.26, and 0.36 items/m3 in Autumn, Winter, Spring and Summer, respectively, and an overall mean concentration of 0.86 ± 0.35 items/m3. A classification based on the shape and appearance of microplastics indicated the predominance of fibers (32%), followed by fragments (27%), films (16%), foams (13%), and granules (12%). A qualitative microplastics analysis through Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) revealed that microplastics were mainly composed of polyethylene (68.2%), polypropylene (24.7%), polystyrene (4.1%) and other polymers (3%). These data provide an initial overview of the quantity, characteristics, and spatio-temporal distribution of floating microplastics in Bou-Ismail Bay (Algeria).

Primer muestreo de microplásticos en arroyos y ríos de la España peninsular

Durante 2019 y 2020 se llevó a cabo una campaña de muestreo para la identificación de microplásticos en 157 arroyos y ríos de la España peninsular. El muestreo se realizó aplicando una metodología desarrollada por HyT (Asociación Hombre y Territorio) en el marco del Proyecto LIBERA y, en concurrencia con una campaña de análisis de contaminantes en IBA (Áreas Importantes para la Conservación de las Aves y la Biodiversidad) llevada a cabo por SEO/BirdLife. Las muestras fueron procesadas inicialmente para la detección de microplásticos bajo lupa y posteriormente fueron sometidas a análisis de espectroscopía infrarroja FTIR (Espectrofotómetro de transformada de Fourier) por el Servicio de Microanálisis de la Universidad de Sevilla. Los resultados de este muestreo, el primero de estas características que se realiza en España para la detección de estos contaminantes, reflejan que más de un 70% de las muestras tienen presencia de microplásticos, con una mayor presencia de fibras, fragmentos y films. Entre las muestras analizadas con FTIR se han identificado un total de 33 polímeros diferentes. El trabajo ofrece, por tanto, datos relevantes acerca de este problema en ríos y arroyos de España.

Microplastic Concentrations in Raw and Drinking Water in the Sinos River, Southern Brazil

Microplastics are omnipresent in the atmosphere, terrestrial and aquatic ecosystems, food and beverages. They may cause risks to biodiversity and the human population. The present study aims to assess the concentrations of microplastics in raw and drinking water of the Sinos River in Southern Brazil. The water was collected at eight locations along the Sinos River and in eight residences supplied with treated river water. The samples were processed by dying plastic particles with Nile Red and counting by fluorescence microscopy. River water showed an average of 330.2 particles L−1 and treated water 105.8 particles L−1. Fibers were the most abundant particles shapes in the samples. Particle abundance in the raw water did not follow the urbanization gradient in the Sinos River basin. The exact pathways of microplastic particles remain unidentified, but the predominance of fibers suggests that untreated sewage from washing machines may be a principal source of contamination, particularly in the headwaters. The microplastic in the drinking water is an additional factor to be considered in conservation efforts aiming at improving water quality in the Sinos River basin.

Glutamine supplementation versus functional overload in extensor digitorum longus muscle hypertrophy

• We compared glutamine supplementation and overload inducing EDL muscle hypertrophy. • Glutamine and overload raised muscle fiber cross-sectional area to a similar extent. • Glutamine potentiated the overload-induced increase in the resistance to fatigue. Abstract Glutamine levels directly associate with total protein content in cultured skeletal muscle cells, whereas glutamine supplementation enhances skeletal muscle mass in catabolic experimental conditions. We compared the effect of glutamine administration on Extensor Digitorum Longus muscle (EDL) weight, fiber cross-sectional area (CSA), contractile activity, and protein metabolism signaling with a functional overload-induced skeletal muscle hypertrophy protocol. Glutamine supplementation raised the predominance of EDL muscle fibers with CSA between 1001 and 2000 μm2 (49.7 %), the p-4E-BP1/total 4E-BP1 ratio, and the effect of overload on resistance to fatigue. The proportion of the EDL muscle fiber CSA distribution for the combination of both treatments was similar to that induced by overload or glutamine separately; 54.3 % muscle fibers with CSA between 1001 and 2000 μm². Glutamine supplementation did not markedly affect the changes induced by overload on protein synthesis signaling pathways, except for a further increase of the p-4E-BP1/total 4E-BP1 ratio. The effect of glutamine on EDL muscle fiber CSA distribution and protein synthesis signaling mimicked the response to overload. The association of glutamine and overload induced EDL muscle hypertrophy further increased the resistance to fatigue.

Strongly Hydrophobic and Superoleophilic PMMA Based Nanocoated Cotton Fabrics

Oil–water separation is among the critical issues worldwide due to recent massive oil spills. Moreover, domestic and industrial water pollution due to oil discharge affects marine and aquatic life. Cotton is the most predominant fiber globally because of its use as a principal and popular clothing material. Cotton is also the leading raw material for technical and functional textile applications. In this study, the fabric was cured with poly (methyl methacrylate) (PMMA) nanoparticles to develop hydrophobic and oleophilic cotton fabrics. The dehydrating agents, N,N′-dicyclohexylcarbodiimide (DCC) and dimethyl aminopyridine (DMAP), were used to catalyze the esterification. The results proved that the excellent hydrophobicity of modified cotton fabric provides a water contact angle higher than 140°. In addition, Fourier transforms infrared (FTIR) spectroscopy, as well as X-ray photoelectron spectroscopy (XPS) analysis, confirmed the fabric surface modification. Surface morphological analysis by scanning electron microscope (SEM) revealed the uniform rough surface structure of the modified fabric with nano-coating. The modified fabric resulted in the high separation efficiency of oil and water, suggesting this strategy to be suitable for advanced oil–water separation.

CONGENITAL MYOPATHIES 2: P.103 Congenital neuromuscular disease with uniform type 1 fibers due to RYR1 mutation is a de facto core myopathy

Typical central core disease (CCD) is characterized pathologically by the presence of a ``core'' which is devoid of oxidative enzyme activity in the central region of myofibers, and is typically accompanied by a strong type 1 fiber predominance (> 99%), referred to as type 1 fiber uniformity. Congenital neuromuscular disease with uniform type 1 fibers (CNMDU1) is characterized pathologically by the presence of essentially identical type 1 fiber uniformity but without the abnormal structural changes in muscle fibers.

The Influence of Anterior Cruciate Ligament Matrix Mechanical Properties on Simulated Whole-Knee Biomechanics.

Knee finite element (FE) models are used to study tissue deformation in response to complex loads. Typically, ligaments are modeled using transversely isotropic, hyperelastic material models fitted to tension data along the predominant fiber direction (longitudinal) and, less commonly, to tension data orthogonal to the fiber direction (transverse). Currently, the shear and bulk responses of the anterior cruciate ligament (ACL) are not fitted to experimental data. In this study, a newly proposed material model was fitted to longitudinal tension, transverse tension, and shear experimental data. The matrix transverse tensile, shear, and bulk stiffnesses were then varied independently to determine the impact of each property on knee kinematics and tissue deformation in a whole-knee FE model. The range of values for each parameter was chosen based on published FE studies of the knee. For a knee at full extension under 134 N anterior tibial force (ATF), increasing matrix transverse tensile stiffness, shear stiffness, or bulk stiffness decreased anterior tibial translation (ATT), ACL longitudinal strain, and ACL shear strain. For a knee under 134 N ATF and 1600 N compression, changing the ACL matrix mechanical properties caused variations in ATT and thus changed cartilage deformation contours by changing the point of contact between the femoral and the tibial cartilage. These findings indicate that material models for the ACL must describe matrix material properties to best predict the in vivo response to applied loads.

Muscular pathological features in patients with Lambert-Eaton myasthenic syndrome associated with small cell lung carcinoma.

Lambert-Eaton myasthenic syndrome (LEMS) is a kind of autoimmune disease of the neuromuscular junction that is often misdiagnosed as a peripheral nerve disease or myopathy. For some difficult cases, muscle biopsy examination is useful for differential diagnosis. However, studies about the pathological findings of LEMS patients are rare, especially of patients who were diagnosed with small cell lung carcinoma (SCLC). This study aimed to describe several pathological muscle features in patients with LEMS associated with SCLC. The 5 patients enrolled in this study were diagnosed with LEMS associated with SCLC by clinical manifestation, electromyography, and lung biopsy. Muscle biopsies were performed for the patients, and enzyme histopathology was assessed. The hematoxylin and eosin (H & E) stain showed different sizes of fibers, and the shape of atrophic fibers were angular or polygonal. The adenosine triphosphatase (ATPase) stain demonstrated that the majority of atrophic fibers were type II. Type II fiber predominance was observed in case 1 and case 5. Also, scattered muscle fiber necrosis was shown in case 3. Type II fiber atrophy and type II fiber predominance may often be found in patients with LEMS associated with SCLC. Also, scattered fiber necrosis may appear in this disease.

Anisotropic tensile behaviour of short glass-fibre reinforced polyamide-6

This paper presents an experimental investigation of injection-moulded short glass-fibre reinforced polyamide-6 reinforced with 0 wt.%, 15 wt.% and 30 wt.% fibres. The fibre orientation distributions are characterized by use of X-ray computed tomography. A shell-core-shell structure is found through the thickness of the materials, where the predominant fibre orientation is along the mould flow direction (MFD) in the shell layers and perpendicular to the MFD in the core layer. To study the mechanical behaviour, uniaxial tensile tests are conducted in seven directions relative to the MFD. The tests are instrumented with two cameras, which allows for accurate measurement of all strain components. The fibre-reinforced materials show moderate to high degree of anisotropy, increasing with the fibre content. Young’s modulus, in-plane and out-of-plane Poisson’s ratio, stress at maximum force and fracture strain vary smoothly with the in-plane specimen angle. It is demonstrated that orthotropic elasticity is an excellent approximation for the anisotropic elastic behaviour of the fibre-reinforced materials.

Structural remodelling of the heart valves extracellular matrix during embryo development.

Alterations in heart valve development represent more than 20% of congenital cardiovascular malformations. Most of the functional properties of heart valves depend on extracellular matrix. Despite its relevance, little is known about fibrillar components on developing stages. Our objective is to define histological changes on valves fibrillar components in late embryonic development of Mus musculus. We found type III collagen as the predominant fibre type in the ECM in prenatal stages followed by a switch to a type I predominance for postnatal ages. The change in fibrillar components is necessary to support the normal mechanical function of adult heart valves.

Tissue Ingrowth Markedly Reduces Mechanical Anisotropy and Stiffness in Fibre Direction of Highly Aligned Electrospun Polyurethane Scaffolds.

The lack of long-term patency of synthetic vascular grafts currently available on the market has directed research towards improving the performance of small diameter grafts. Improved radial compliance matching and tissue ingrowth into the graft scaffold are amongst the main goals for an ideal vascular graft. Biostable polyurethane scaffolds were manufactured by electrospinning and implanted in subcutaneous and circulatory positions in the rat for 7, 14 and 28 days. Scaffold morphology, tissue ingrowth, and mechanical properties of the scaffolds were assessed before implantation and after retrieval. Tissue ingrowth after 24 days was 96.5 ± 2.3% in the subcutaneous implants and 77.8 ± 5.4% in the circulatory implants. Over the 24 days implantation, the elastic modulus at 12% strain decreased by 59% in direction of the fibre alignment whereas it increased by 1379% transverse to the fibre alignment of the highly aligned scaffold of the subcutaneous implants. The lesser aligned scaffold of the circulatory graft implants exhibited an increase of the elastic modulus at 12% strain by 77% in circumferential direction. Based on the observations, it is proposed that the mechanism underlying the softening of the highly aligned scaffold in the predominant fibre direction is associated with scaffold compaction and local displacement of fibres by the newly formed tissue. The stiffening of the scaffold, observed transverse to highly aligned fibres and for more a random fibre distribution, represents the actual mechanical contribution of the tissue that developed in the scaffold.

Abundance and characteristics of microfibers detected in sediment trap material from the deep subtropical North Atlantic Ocean

Plastics and microplastics increasingly gain importance due to their perils and wide distribution in the marine environment. Microfibers account for the largest percentage of anthropogenic-induced microparticles, which inter alia, consist of plastic, and are found in deep-sea sediments. However, the sinking of fibers from the surface through the water column to the seafloor is still poorly understood. The present study investigates microfibers extracted from sediment trap samples, which were deployed in the North Atlantic Subtropical Gyre (NASG). The average result of eleven analyzed samples showed 913 microfibers per gram of collected particle flux material, with a predominant fiber length shorter than 1 mm (75.6%) and a distribution maximum between 0.2 and 0.4 mm. Further, the average number of microfibers found in this study was used to derive microfiber fluxes for the NASG based on the deployment time of the sediment trap. Extrapolating the computed flux of 94 microfibers m−2 day−1 to the entire NASG area would correspond to a total microfiber mass flux of 9800 t a−1 or 73 × 1013 microfibers a−1 of sinking microfibers through the water column. These findings offer an extended application of sediment traps to monitor microfiber fluxes, which reveals the opportunity to investigate the mechanism driving sinking of microfibers and microplastics into the deep open ocean.

Rethinking Neuropathy in Type 1 Diabetes: Had We Lost Sight of What Matters Most?

Although animal and human physiological studies have informed potential mechanisms of diabetic neuropathy (1), the real‐world variability in clinical presentation and complexities in measurement have severely hindered a clear understanding of its epidemiology, its impact on the population with type 1 diabetes, and the development of therapies. The most common form—and therefore the one usually referred to simply as “diabetic neuropathy”—is the diffuse, symmetrical, slowly progressive, length‐dependent damage to the peripheral and autonomic nervous system classified technically by the term “diabetic distal symmetrical polyneuropathy” (1). It remains asymptomatic for years, may first present with abnormal sensation symmetrically at the tips of the toes, and may over time spread to the stocking‐and‐glove distribution. It involves injury to different anatomical nerve types that show variable clinical manifestations between individuals. Nerves can be classified as small, thinly myelinated or unmyelinated fibers that make up the autonomic as well as the pain and temperature sensory fibers, while large, myelinated fibers are responsible for other sensory and skeletal muscle functions. Some people have a large fiber–predominant pattern and experience numbness, tingling, or imbalance, while others have small fiber–predominance with burning and stabbing pain, impairment in sensing heat and cold, or a propensity toward clinical autonomic abnormalities like lightheadedness or gastroparesis (1). Some people experience a combination, and regardless of the pattern, people can be asymptomatic for extended periods even though their physical examination or specialized testing reveals marked impairments in nerve structure and function. With progression to foot muscle weakness or clinical autonomic manifestations like dry feet from limited sweat production, the subsequent risk of ulcer, infection, and amputation intensify. Complications like these are feared by people with diabetes more than death itself (2), and of great concern is the recent evidence of a resurgence in amputations (3–5). To study the outcomes …

Strenuous Acute Exercise Induces Slow and Fast Twitch-Dependent NADPH Oxidase Expression in Rat Skeletal Muscle.

The enzymatic complex Nicotinamide Adenine Dinucleotide Phosphate (NADPH) oxidase (NOx) may be the principal source of reactive oxygen species (ROS). The NOX2 and NOX4 isoforms are tissue-dependent and are differentially expressed in slow-twitch fibers (type I fibers) and fast-twitch fibers (type II fibers) of skeletal muscle, making them different markers of ROS metabolism induced by physical exercise. The aim of this study was to investigate NOx signaling, as a non-adaptive and non-cumulative response, in the predominant fiber types of rat skeletal muscles 24 h after one strenuous treadmill exercise session. The levels of mRNA, reduced glycogen, thiol content, NOx, superoxide dismutase, catalase, glutathione peroxidase activity, and PPARGC1α and SLC2A4 gene expression were measured in the white gastrocnemius (WG) portion, the red gastrocnemius (RG) portion, and the soleus muscle (SOL). NOx activity showed higher values in the SOL muscle compared to the RG and WG portions. The same was true of the NOX2 and NOX4 mRNA levels, antioxidant enzymatic activities, glycogen content. Twenty-four hours after the strenuous exercise session, NOx expression increased in slow-twitch oxidative fibers. The acute strenuous exercise condition showed an attenuation of oxidative stress and an upregulation of antioxidant activity through PPARGC1α gene activity, antioxidant defense adaptations, and differential gene expression according to the predominant fiber type. The most prominent location of detoxification (indicated by NOX4 activation) in the slow-twitch oxidative SOL muscle was the mitochondria, while the fast-twitch oxidative RG portion showed a more cytosolic location. Glycolytic metabolism in the WG portion suggested possible NOX2/NOX4 non-regulation, indicating other possible ROS regulation pathways.

Fate of microplastics in wastewater treatment plants and their environmental dispersion with effluent and sludge

This work studied the occurrence of microplastics in primary and secondary effluents and mixed sludge of a WWTP as well as in processed heat-dried sludge marketed as soil amendment. Sampled microparticles were divided into fragments and fibres, the latter defined as those with cylindrical shape and length to diameter ratio >3. We showed the presence of 12 different anthropogenic polymers or groups of polymers with a predominance of polyethylene, polypropylene, polyester and acrylic fibres together with an important amount of manufactured natural fibres. The smaller sampled fraction, in the 25–104 μm range, was the largest in both primary and secondary effluents. Fibres displayed lower sizes than fragments and represented less than one third of the anthropogenic particles sampled in effluents but up to 84% of heat-dried sludge. The plant showed a high efficiency (>90%) in removing microplastics from wastewater. However, the amount of anthropogenic plastics debris in the 25 μm - 50 mm range still released with the effluent amounted to 12.8 ± 6.3 particles/L, representing 300 million plastic debris per day and an approximate load of microplastics of 350 particles/m3 in the receiving Henares River. WWTP mixed sludge contained 183 ± 84 particles/g while heat-dried sludge bore 165 ± 37 particles/g. The sludge of the WWTP sampled in this work, would disseminate 8 × 1011 plastic particles per year if improperly managed. The agricultural use of sludge as soil amendment in the area of Madrid could spread up to 1013 microplastic particles in agricultural soils per year.

Sustainable reuse of fashion waste as flame-retardant mattress filing with ecofriendly chemicals

Abstract There has been increased attention from global organisations and fashion brands on the problems associated with fashion waste. This study sought to recycle fashion waste clothing collected from Australian consumers into fibre blends to reuse as a filling material in children’s mattresses. The fibre blends were quantitatively analysed for composition. Then the fibers were treated with eco-friendly flame-retardant finishes, and the flame retardancy was evaluated by limiting oxygen index and electrical burner test. The treated fibres were further characterised by thermogravimetric analysis, Fourier-transform infrared, and X-ray diffraction. The quantitative fibre blend analysis indicated that the predominant fibres used in the clothing of Australian consumers are cotton, followed by polyester. The application of green flame-retardant finishes aided in the improvement of the flame retardancy to the standard level, as shown by the limiting oxygen index and electrical burner test. It was also observed that the flame-retardant finish increased the thermal stability of the fibre blend, which delayed and reduced the thermal degradation and decomposition of the mattress filling. Furthermore, the presence of the flame-retardant finish was determined by the Fourier-transform infrared, but there was no change to the chemical composition of the treated fibre blend samples.

Disulfiram (Antabuse) Neurotoxicity: Implications of Painful Small Fiber Sensory Polyneuropathy for Lyme Disease and Addiction

This article describes the prototypical clinical presentation, electrodiagnostic and neuropathological findings and treatment of a patient with painful peripheral neuropathy due to disulfiram toxicity. Although a review of the literature fails to reveal cases of painful peripheral neuropathy due to disulfiram toxicity, there has been heightened publicity of its risk in the treatment of persistent symptoms of Lyme disease following a standard of care course of antibiotics known as post-treatment Lyme disease syndrome. This article reviews the etiopathogenesis and diagnosis of predominant small fiber neuropathy resulting from disulfiram neurotoxicity, and offers recommendations for its use in Lyme disease and alcoholism.

Accumulation of microplastics in typical commercial aquatic species: A case study at a productive aquaculture site in China

The widespread occurrence of microplastics in the marine environment has drawn global attention because microplastics may impact the populations of marine organisms. As such, aquaculture industry may suffer from microplastic pollution, especially when plastic products are widely used for aquaculture. Here, we assessed the abundance and characteristics (type, size and composition) of microplastics in sediment and typical commercial species (fish, bivalves and shrimps) in an aquaculture site at Xiangshan Bay, which has been operated intensively for decades. Satellite remote sensing images revealed that aquaculture activities were associated with microplastic pollution in sediment, where the microplastics (51–88 items/kg dry weight) were mostly fibres (>94%) and between 500 and 2000 µm. Cellulose was the predominant polymer (60–88% of microplastic composition), followed by polypropylene. Microplastics accumulated in all the commercial species (0.95–2.1 items per individual), where shrimp (Parapenaeopsis hardwickii) had lower potential for microplastic accumulation than the other species. The predominance of fibres and cellulose in the commercial species implies their limited ability to recognize the type and composition of microplastics during ingestion. Given the limited accumulation of microplastics in these typical commercial species even at a productive aquaculture site, we suggest that microplastics may not increase the health risk of consuming seafood and their impacts on commercial species may be less deleterious than previously thought.

P.236Myofibres with subsarcolemmal rims and/or central aggregates of mitochondria (SRCAM) are prevalent in congenital titinopathies

With increasing use of massive parallel sequencing over recent years, congenital titinopathies due to recessively inherited truncating and/or splice-site pathogenic variants in TTN (which encodes titin) are emerging as a common cause of congenital myopathy (CM). The clinical phenotype is broad. Muscle biopsies show structural abnormalities including cores, central nuclei (CN) and fibre size disproportion. We report a novel structural abnormality prevalent in muscle biopsies from a cohort of patients with clinical and/or pathological features (cores and/or central nuclei and slow fibre predominance) of CM. Cases were classified genetically as "definite" (2 predicted pathogenic TTN variants), "probable" (1 predicted pathogenic and 1 missense variant) and ''possible'' (1 predicted pathogenic or 2 missense variants) titinopathy. The index case, a male with recessive splice-site TTN variants in trans, presented at birth, with profound hypotonia, respiratory weakness and cardiomegaly. CK was normal. EMG was myopathic. Quadriceps biopsy at 2 months showed mild CN and ill-defined cores. A novel observation concerned a striking sub-population of fibres, often smaller, with circumferential rims with/without central aggregates of oxidative staining. These were designated as myofibres with subsarcolemmal rims and/or central aggregates of mitochondria (SRCAM fibres). We subsequently identified SRCAM fibres in 35.7% of genetically definite or probable/possible TTN-CM cases (10/28 total; 4/9 definite, 2/3 probable and 4/16 possible). In stark contrast, SRCAM fibres were present in only 3.6% (2/56) of cases with pathogenic variants in other core/CN-CM genes (RYR1, SEPN1, MYH7, MYH2, DNM2, MTM1). They were most frequent in neonates. Analysis of additional cases and ultrastructural characterisation is ongoing. We recommend that patients with a clinicopathological picture compatible with CM and presence of SRCAM fibres in their muscle biopsy should be screened for TTN mutations.