Percentage Of Fibers Research Articles

Durability Studies and Stress Strain Characteristics of hooked end steel fiber reinforced ambient cured geopolymer concrete

Abstract For conventional concrete, the use of fibers has proven to improve the strength properties of the material. However, in the case of ambient cured geopolymer concrete, there are limited studies that explore the application of fibers, in particular, the use of hooked end steel fibers. Further, it is important to study the durability properties of geopolymer concrete with fibers, since it will influence the service life of the structures in practice. Therefore, in the present study, fiber-reinforced geopolymer concrete was synthesized using fly ash, GGBS, hooked end steel fibers, and alkaline solution made with Na2SiO3 and NaOH. The percentage of steel fibers varied in the range of 0.5% to 2% with an increment of 0.5% by volume fraction of the binder. The precursor materials were characterized using techniques such as X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscope (SEM). Durability studies like water absorption, drying shrinkage, sulphate attack were studied. In addition, the elastic constants were determined through stress strain behaviour of geopolymer concrete in uniaxial compression. The results of the experimental study showed that the addition of hooked end steel fibers influences the strength of geopolymer concrete up to an optimal percentage, which was found to be 1%. Furthermore, in terms of durability properties, the addition of fibers exhibited better results in terms of resistance to water absorption and chemical attack, and this was validated by the microstructural studies, where the specimens with hooked end steel fibers revealed much denser hardened geopolymer matrix when compared to the mixes without fibers.

Strengthening of flexural behavior of reinforced concrete beams by using hybrid fibers: experimental and analytical study

The research investigates the flexural behavior of reinforced concrete (RC) beams by incorporating hybrid fibers (a combination of glass and steel fibers). Ten specimens measuring 150 mm x 200 mm x 1500 mm were cast and tested under two-point loading. The specimens were divided into three groups, each containing three specimens. Additionally, a control specimen was examined. Comparing the strength performance of each group to the control specimen revealed that the hybrid fiber-reinforced beams exhibited increased strength. The optimal hybrid fiber composition was 0.4% steel and 0.2% glass fiber. Similarly, the optimal steel and glass fiber percentages were both 0.4%. Experimental results showed that the load-carrying capacity improved significantly: 28.80% with glass fiber, 63.74% with steel fiber, and 79.23% with hybrid fiber compared to conventional RC beams. The study evaluated load-carrying capacity, load deflection, ductility, stiffness, and failure modes of RC beams. An analytical study using finite element modelling was conducted, and the analytical results were compared to experimental findings. Fundamental statistical values included mean, standard deviation, and coefficient of variation for load and deflection. Finite element analysis (FEA) was employed to predict experimental outcomes, and the analytical results closely correlated with experimental data. The load mean, standard deviation and coefficient of variation were 0.98, 0.01, and 0.56, respectively. The deflection exhibited corresponding values of 0.97, 0.01, and 1.41. The graphical abstract of the present study is displayed in Figure 1.

Development and characterization of hybrid polymer composite materials with reinforcement of glass/carbon fibers for enhanced mechanical properties: an experimental and numerical approach

Composite materials, particularly fiber-reinforced plastics (FRP), are used in aerospace and automotive industries due to their desirable properties and surpassing traditional metals in various applications. Researchers are countering the drawbacks of using a single fiber type in FRP by creating hybrid composites that combine different fibers in a single matrix. These hybrids harness the cost-effectiveness and corrosion resistance of glass fibers alongside the strength and stiffness of carbon fibers, resulting in a balanced combination of properties for various applications. Tensile tests were performed according to the ASTM D3039 standard, with a 2 mm/min strain rate. The results showed that increasing the carbon fiber percentage (6.56%, 13.79%, and 21.07%) led to significant improvements in the tensile strength of the hybrid composites (34.18%, 55.44%, and 85.40% higher than glass fiber composites). However, changing the stacking sequence did not significantly affect tensile strength, indicating its insignificance in this regard. Numerical simulations were conducted to validate the experimental results, and the errors between experimental and numerical data were below 10% for various stacking sequences. These discrepancies were attributed to factors such as fiber waviness, which resulted in heterogeneous property distribution within the composites, and the manufacturing process used for creating the hybrid composites. Scanning electron microscope analysis was also performed to study the failure modes on the fracture surface of the tensile-tested specimens.

Effect of process parameters on the rheological properties of banana (Musa acuminata) fiber and optimization using response surface methodology

The labor-intensive, time-consuming, and uneconomical nature of manually extracting banana (Musa acuminata) fibers from pseudo-stem sheaths has prompted the exploration of automation as a solution. This study focuses on automating the feeding process of banana pseudostem sheaths using a quick return mechanism, which is more effective than other approaches. A comprehensive study was conducted to assess the impact of key process parameters, namely the decorticator (480–540 rpm), roller speed (50–80 rpm), and clearance between rollers (2–4 mm), on the mechanical properties of the extracted banana fiber. The Response Surface Methodology (RSM) was employed for the experimental design and analysis of data, and the mechanical properties under investigation included the tensile strength, Young's modulus, and strain percentage of the banana fiber. The results revealed that the decorticator speed, roller speed, and clearance between rollers are significantly influenced by their mechanical properties. Herein, the optimal process parameter values are identified as follows: a decorticator speed of 510 rpm, roller speed of 65 rpm, and clearance of 3 mm between rollers. The mechanical characterization of the optimized banana fiber exhibited impressive properties, with an ultimate tensile strength of 679.48 MPa, Young's modulus of 25.47 GPa, and strain of 3 %. This study demonstrates that automation coupled with systematic parameter optimization can enhance the mechanical attributes of banana fibers. This research not only addresses the challenges of manual extraction, but also advances the understanding of how process parameters affect banana fiber quality, thereby facilitating the utilization of this natural fiber in various industrial applications.

Influence of melatonin supplementation on tissue response of endodontic sealers in Wistar rats.

This study evaluated the influence of melatonin supplementation on tissue's response of endodontic sealers in Wistar rats. Forty-eight rats received subcutaneous implants of four polyethylene tubes: one empty (control) and three filled with endodontic sealers (AH Plus, Endofill and Sealapex). Half of the animals were supplemented with melatonin (ME) and the remaining treated with water (WA) for 15days before the implantation until euthanasia, forming the groups: control-WA, AH Plus-WA, Endofill-WA, Sealapex-WA, Control-ME, AH Plus-ME, Endofill-ME and Sealapex-ME. After 5, 15 and 30days, (n = 8) tubes were removed and evaluated in H&E., immunohistochemistry, PSR, VK and POL. The results were statistically analyzed (p < 0.05). In animals treated with water, Endofill-WA evoked more intense inflammatory infiltrate compared to AH Plus-WA and Control-WA in a 30-day period (p < 0.05). In animals supplemented with melatonin, there was any difference among endodontic sealers' response in any period of analysis (p > 0.05). Comparing the individual response of each sealer, over a 30-day period, Endofill-ME and Sealapex-ME showed less inflammatory infiltrate compared to Endofill-WA and Sealapex-WA, respectively (p < 0.05). Immunostaining for IL-6 and TNF-α was less intense for all groups in animals supplemented with melatonin, in most periods, except for the Endofill sealer (p < 0.05). Furthermore, Endofill-ME at 5days and AH-Plus-ME at 30days showed a higher percentage of mature collagen fibers compared to the Endofill-WA and AH Plus-WA, respectively (p < 0.05). Positive structures for von Kossa staining and birefringent to polarized light were observed only for Sealapex-WA and Sealapex-ME in all periods. It can be concluded that melatonin influences the tissue response to endodontic sealers, modulating the inflammatory and reparative process.

Association analysis of indel variants and gene expression identifies MDM4 as a novel locus for skeletal muscle hypertrophy and power athlete status.

Insertions and deletions (indels) are the second most common type of variation in the human genome. However, limited data on their associations with exercise-related phenotypes have been documented. The aim of the present study was to examine the association between 18,370 indel variants and power athlete status, followed by additional studies in 357,246 individuals. In the discovery phase, the D allele of the MDM4 gene rs35493922 I/D polymorphism was over-represented in power athletes compared with control subjects (P=7.8×10-9) and endurance athletes (P=0.0012). These findings were replicated in independent cohorts, showing a higher D allele frequency in power athletes compared with control subjects (P=0.016) and endurance athletes (P=0.031). Furthermore, the D allele was positively associated (P=0.0013) with greater fat-free mass in the UK Biobank. MDM4 encodes a protein that inhibits the activity of p53, which induces muscle fibre atrophy. Accordingly, we found that MDM4 expression was significantly higher in the vastus lateralis of power athletes compared with endurance athletes (P=0.0009) and was positively correlated with the percentage of fast-twitch muscle fibres (P=0.0062) and the relative area occupied by fast-twitch muscle fibres (P=0.0086). The association between MDM4 gene expression and an increased proportion of fast-twitch muscle fibres was confirmed in two additional cohorts. Finally, we found that the MDM4 DD genotype was associated with increased MDM4 gene expression in vastus lateralis and greater cross-sectional area of fast-twitch muscle fibres. In conclusion, MDM4 is suggested to be a potential regulator of muscle fibre specification and size, with its indel variant being associated with power athlete status. HIGHLIGHTS: What is the central question of this study? Which indel variants are functional and associated with sport- and exercise-related traits? What is the main finding and its importance? Out of 18,370 tested indels, the MDM4 gene rs35493922 I/D polymorphism was found to be the functional variant (affecting gene expression) and the most significant, with the deletion allele showing associations with power athlete status, fat-free mass and cross-sectional area of fast-twitch muscle fibres. Furthermore, the expression of MDM4 was positively correlated with the percentage of fast-twitch muscle fibres and the relative area occupied by fast-twitch muscle fibres.

Nutritional Value, Bioactive Compounds, and Antioxidant Activity of Phak-liang (Gnetum gnemon Linn. var. tenerum Markgr.) in Surat Thani Province, Thailand

The nutritional value, bioactive compounds, and antioxidant activity of Phak-liang (Gnetum gnemon Linn. var. tenerum Markgr.) were investigated. The indigenous vegetables were collected from three districts; Muang, Bannasarn, and Khirirat Nikom in Surat Thani Province. The nutritional value of the samples was carried out according to the methods of AOAC. The moisture contents ranged from 84.72-87.52%, and the ash contents ranged from 0.78-1.07% fresh weight. The percentage of fiber, protein, fat, and carbohydrate in the leafy vegetables were in the range of 3.06-3.81, 3.44-4.68, 0.65-1.08 and 7.49-9.55 fresh weight, respectively. The samples were analyzed by ICP-OES for their mineral determinations. The amounts found in the samples, in descending order were: K &gt; Ca &gt; Mg &gt; Mn &gt; Na&gt; Fe &gt; Zn &gt; Cu. Considering the amounts of minerals found in the vegetable and their recommended daily values by the Bureau of Nutrition (Ministry of Public Health, Thailand), the daily value (DV) percentage of Mn in the samples were relatively high (28.45-96.65%), whereas K, Mg, Ca, Fe, Cu and Zn contributed from 1.29–8.42% of the daily values. The vegetable had negligible amounts of Na (0.03 - 0.07% of the DV). The antioxidant capacities were analyzed using Ferric Reducing Antioxidant Power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The results showed that antioxidant activity increased by the concentration of the ethanol extracts. The FRAP values of the extracts ranged from 89.01-160.70 µM FeSO4/100 g dry weight, and the IC50 values calculated for DPPH radical scavenging activities of the extracts ranged from 54.37-60.57 mg/mL. The results suggested that Phak-liang is a potential source of natural phytochemicals and could be used for health promotion in the community.

Comparative Study of Reinforced Concrete Using Human Hair and Aluminum Fibres

This study investigates the efficacy of human hair and aluminum fibres as reinforcements in concrete, analyzing their impact on compressive, flexural, and tensile strengths. Different fibre percentages (0%, 0.5%, 1%, and 1.5% by weight of cement) are systematically incorporated into concrete mixtures. Compressive strength tests on cubes, flexural strength assessments on beams, and tensile strength evaluations on cylinders reveal insights into the material's load-bearing, bending, and stretching capacities. Human hair-reinforced concrete showed significant improvements in compressive strength. Results indicate a gradual strength increase in Human Hair Fibre Reinforced Concrete (HHFRC) up to an optimal percentage. At the same time, Aluminum Fibre Reinforced Concrete (AFRC) shows significant enhancement in higher fibre content. AFRC's superior mechanical properties stem from aluminum fibres high tensile strength and stiffness, enhancing bond formation and resulting in denser, stronger concrete. These findings inform the selection of fibre reinforcement for concrete structures tailored to specific project needs.

Controlling changes caused by holes by adding fibers to composite concrete components

Crack propagation can be affected by the holes of the placement of rebars in the reinforced concrete and the resulting changes in the homogeneous structure of concrete. This experimental study aimed at investigating the fiber self-compacting concrete failure and crack propagation in concrete specimens with circular central holes and contain 2, 4, and 8 fiber percentages. The crack propagation mechanisms under the uniaxial compressive strength of the concrete were studied by investigating the holes created by rebars buried in the reinforced concrete. Three concrete mix designs with different compressive strengths of 27, 30, and 33 MPa were used for detailed analysis of the fiber concrete behavior by 224 standard 150 mm cubic specimens. The results showed the insignificant impact of small holes with an approximate area of 1.4% of the specimen surface area on the failure structure so that crack propagation in this case was similar to that occurred in the hole-free concrete. The compressive strength of concrete decreased, by increasing the crack prorogation around the holes. The compressive strength of the concrete may be reduced significantly by increasing the hole diameter. Taking into account these factors in the design of the connection core can reduce the compressive strength of concrete by 30% depending on the rebar grid.

One Year of Heavy Resistance Training Modifies Muscle Fiber Characteristics in the Elderly.

Physical function declines with age, accelerating during the 6th decade of life, primarily due to loss in muscle mass and strength. The present study aimed to investigate the effect of one year of heavy resistance training in older adults (62-70 years) on muscle mass and strength. Further, we investigated muscle characteristics after the intervention by obtaining muscle biopsies from the vastus lateralis to compare muscle fiber characteristics between the heavy resistance training (HRT) (n=10) and the sedentary control group (CON) (n=10). We found that one year of resistance training increased isometric muscle strength (p<0.0001, ES: 2.43 (Hedges' g)) and lean body mass (p<0.05, ES: 0.96), whereas cross-sectional area of the vastus lateralis and lean leg mass were unaltered. At year 1, the percentage of type IIX muscle fibers was lower in HRT compared to CON (p<0.05, ES: 0.99), whereas the muscle fiber size did not differ between groups for the major fiber types (I and II). In conclusion, one year of resistance training in elderly improved muscle strength and lean body mass but not cross-sectional area and lean leg mass. This indicates that the increase in muscle strength may be caused by neuromuscular adaptations rather than morphological muscle tissue changes per se.

Development of innovative alkali activated paste reinforced with polyethylene fibers for concrete crack repair.

Concrete structures are susceptible to cracking, which can compromise their integrity and durability. Repairing them with ordinary Portland cement (OPC) paste causes shrinkage cracks to appear in the repaired surface. Alkali-activated binders offer a promising solution for repairing such cracks. This study aims to develop an alkali-activated paste (AAP) and investigate its effectiveness in repairing concrete cracks. AAPs, featuring varying percentages (0.5%, 0.75%, 1%, 1.25%, 1.5%, and 1.75%) of polyethylene (PE) fibers, are found to exhibit characteristics such as strain hardening, multiple plane cracking in tension and flexure tests, and stress-strain softening in compression tests. AAP without PE fibers experienced catastrophic failure in tension and flexure, preventing the determination of its stress-strain relationship. Notably, AAPs with 1.25% PE fibers demonstrated the highest tensile and flexural strength, exceeding that of 0.5% PE fiber reinforced AAP by 100% in tension and 70% in flexure. While 1% PE fibers resulted in the highest compressive strength, surpassing AAP without fibers by 17%. To evaluate the repair performance of AAP, OPC cubes were cast with pre-formed cracks. These cracks were induced by placing steel plates during casting and were designed to be full and half-length with widths of 1.5 mm and 3 mm. AAP both with and without PE fibers led to a substantial improvement in compressive strength, reducing the initial strength loss of 30%-50% before repair to a diminished range of 2%-20% post-repair. The impact of PE fiber content on the compressive strength of repaired OPC cube is marginal, providing more flexibility in using AAP with any fiber percentage while still achieving effective concrete crack repair. Considering economic and environmental factors, along with observed mechanical enhancements, AAPs show promising potential for widespread use in concrete repair and related applications, contributing valuable insights to the field of sustainable construction materials.

Exercise training induces mild skeletal muscle adaptations without altering disease progression in a TDP-43 mouse model.

Exercise training is considered a nonpharmacological therapeutic approach for many diseases. Mild-to-moderate endurance exercise training is suggested to improve the mental and physical state of people with amyotrophic lateral sclerosis (ALS). The aim of the present study was to determine the capacity of symptomatic rNLS8 mice, which develop ALS-reminiscent TAR DNA-binding protein 43 (TDP-43) pathology and motor dysfunction, to perform mild-to-moderate intensity treadmill exercise training and to evaluate the effects of this training on skeletal muscle health and disease progression. Symptomatic rNLS8 mice were able to complete 4 wk of mild-to-moderate treadmill running (30 min at 6-13 m/min, 3 days a week). Exercise training induced an increase in the percentage of type IIA fibers in the tibialis anterior muscle as well as minor adaptations in molecular markers of myogenic, mitochondrial, and neuromuscular junction health in some forelimb and hindlimb muscles. However, this exercise training protocol did not attenuate the loss in motor function or delay disease progression. Alternative exercise regimens need to be investigated to better understand the role exercise training may play in alleviating symptoms of ALS.NEW & NOTEWORTHY This is the first study to investigate the capacity of symptomatic rNLS8 mice, which develop ALS-reminiscent TDP-43 pathology and motor dysfunction, to perform exercise training. We demonstrate that despite the ALS-reminiscent aggressive disease progression characterizing the rNLS8 mouse model, rNLS8 mice are capable of performing mild-to-moderate endurance treadmill training for at least 3-4 wk. We demonstrate that exercise training induces several minor skeletal muscle adaptations without delaying disease progression in rNLS8 mice.

Effect of Recycled Fibers on the Mechanical Properties and Durability of Sand Concrete

Recycling waste in construction materials is part of a sustainable development approach aimed at creating new materials with characteristics that have been shown to be competitive with traditional materials. In this context, this study aims to recover steel, copper and aluminum wastes from blacksmiths’ workshops together with the reuse thereof in the form of reinforcing fibers in sand concrete. However, in order to assess the impact of this waste on the concrete properties, we introduced such wastes in the form of fibers at different proportions (0.4 %, 0.8 % and 1.2 %). Further, a series of tests was then carried out to determine the evolution of the concrete characteristics in the fresh state (workability and density) and in the hardened state (compressive strength, flexural strength, compressive strength obtained using a sclerometer and the speed of ultrasonic waves), as well as the concrete’s durability (absorption coefficient by immersion, by capillarity and the porosity accessible to water). In closing, the behavior of the concrete was assessed in the face of a chemical attack by H2SO4 and HCl by measuring mass loss. In virtue of thus, the results obtained demonstrated a positive evolution of certain properties of sand concrete as a function of the type and percentage of fibers incorporated into the composition of the concrete.

T-Allele Carriers of Mono Carboxylate Transporter One Gene Polymorphism rs1049434 Demonstrate Altered Substrate Metabolization during Exhaustive Exercise.

Polymorphism rs1049434 characterizes the nonsynonymous exchange of adenosine (A) by thymidine (T) in the gene for monocarboxylate transporter 1 (MCT1). We tested whether T-allele carriers of rs1049434 demonstrate increased accumulation of markers of metabolic strain. Physically active, healthy, young male subjects (n = 22) conducted a power-matched one-legged cycling exercise to exhaustion. Metabolic substrates in capillary blood, selected metabolic compounds, and indices for the slow oxidative phenotype of vastus lateralis muscle were quantified in samples collected before and after exercise. The genotypes of the rs1049434 polymorphism were determined with polymerase chain reactions. One-legged exercise affected the concentration of muscle metabolites entering the tricarboxylic acid cycle, such as acetyl-co-enzyme A (+448%) and acetyl-L-carnitine (+548%), muscle glycogen (-59%), and adenosine monophosphate (-39%), 30 min post-exercise. Exercise-related variability in the muscular concentration of glycogen, long-chain acyl co-enzyme As and a triglyceride, nicotinamide adenine dinucleotide (NADH), and adenosine monophosphate (AMP) interacted with rs1049434. T-allele carriers demonstrated a 39% lesser reduction in glycogen after exercise than non-carriers when NADH increased only in the non-carriers. Muscle lactate concentration was 150% higher, blood triacyl-glyceride concentration was 53% lower, and slow fiber percentage was 20% lower in T-allele carriers. The observations suggest a higher anaerobic glycolytic strain during exhaustive exercise and a lowered lipid handling in T-allele non-carriers.

Bioresin based hybrid green composite preparation using Holoptelea integrifolia fibers reinforced by Ziziphus jujuba seed particles: a fuzzy logic assisted optimization of mechanical behaviour

Abstract In recent years, hybrid natural fiber–reinforced composites prepared by bio-based epoxy resin (BBER) have gained extensive usage due to their exceptional specific strength. Researchers have looked at natural fibre/BBER composites because of the vast array of technical uses for these materials. Experimenting with various composition combinations of hybrid natural fiber composites to improve their mechanical properties requires a significant amount of resources. The purpose of this research was to develop and evaluate a tannic acid (TA) – based bio-based epoxy resin (BBER). The synthesized BBER was analyzed using FTIR spectroscopy. The bio-resin’s thermal characteristics were assessed using TGA, DSC, and OIT studies. Further, this study investigated the mechanical characteristics of hybrid composites prepared by Holoptelea integrifolia (HIBF) bark fibre reinforced with Ziziphus jujuba Seed Particles (ZJSP) which was manufactured using BBER. In the present study, a full factorial design was used to conduct experiments, which included three variables: the percentage of HIBF fibre by weight, the particle size of ZJSP, and the percentage of ZJSP by weight. The experimental results from the mechanical evaluation of the hybrid HIBF/ZJSP using BBER composites are then used to develop a fuzzy model that predicts mechanical parameters such as tensile strength (TS), flexural strength (FS), and impact strength (IS). An accurate prediction of the mechanical characteristics of hybridized composites made by the fuzzy model owing to the membership functions that were built. To further validate the fuzzy model, a set of tests utilising test cases were conducted. The model’s accuracy in predicting the mechanical characteristics of hybrid composites was determined to be 87 % based on the outcomes of the test cases.

Coupled Effects of High Temperature and Steel Fiber Content on Energy Absorption Properties of Concrete.

The associated effects of temperature and steel fiber content on the energy absorption properties of concrete were examined using quasi-static uniaxial compression tests of concrete materials with varied steel fiber contents (0%, 0.5%, 1%, and 1.5%) at various temperatures (20 °C, 200 °C, 400 °C, and 520 °C). The experimental findings demonstrate that steel fibers can greatly boost concrete's ability to absorb energy and that the toughness index rises with steel fiber concentration. The energy absorption capacity of concrete under high-temperature conditions also significantly decreases as temperature rises, and the energy absorption ability of steel fiber concrete under the same temperature is superior to that of plain concrete. The coupled influence factor K of temperature-steel fiber percentage characterizing the energy-absorbing ability of concrete was determined, and the coupled influence law of temperature and steel fiber content on the energy-absorbing capacity of concrete materials was summarized and analyzed on the basis of the experimental data of high-temperature compression. Equivalent equations for steel fiber reinforcing and temperature weakening effects when they are comparable (K = 1) are developed and equivalent parameters for concrete materials are given.

Fiber production repeatability and selection of promising fique (Furcraea spp.) genotypes

AbstractGlobally, natural fibers are important at reducing the using nonrecyclable synthetic fibers; therefore, cultivating fique can help supply the demand for nonplastic packaging in the Colombian and international markets. Corporación Colombiana de Investigación Agropecuaria has a working collection of fique located at La Selva‐Rionegro Research Center (Antioquia‐Colombia). This work evaluated the repeatability coefficient of 68 Furcraea accessions harvested from 2019 to 2022. Repeatability coefficients of 0.293 and 0.149 were found for total dry fiber yield and dry fiber percentage, respectively. The yield‐stability selection index was calculated for the evaluated traits, by which 10 promising accessions were selected, representing 14% of the evaluated population. In addition, correlation coefficients were calculated between productive variables and some meteorological variables (accumulated rainfall, average maximum, and minimum temperatures, and accumulated solar radiation. The accumulated rainfall at 101 days showed the highest correlation with values of 0.429 and 0.488 for the total dry fiber production and the percentage of dry fiber, respectively. The average minimum temperature presented positive correlations with the productive performance of fique.

Is Partial ACL Tear a Cause of Painful Swollen Knees?

Abstract Study Design: Retrospective case series. Objective: In this study, we will identify if partial ACL tear is a common hidden cause of chronic pain and swelling of the knee in adults. And we will evaluate the effectiveness of arthroscopic selective bundle reconstruction in the management of this condition. Background: The Anterior Cruciate Ligament (ACL) has two anatomical bundles, the anteromedial (AM) and the posterolateral (PL), each bundle was named according to the site of its tibial insertion.[1] Partial ACL tear is evident and symptomatic when the percentage of the torn fibers is more than 50% of ligament fibers. AM bundle is more liable to injury than PL.[2] Symptomps of partial ACL tear may be giving way and instability but persistent knee pain and swelling is often present as the main presenting symptom of the patient due to micro-instability of the knee, The primary complication of longstanding partial ACL tears is early knee degeneration.[3] Patients and Methods: 37 patients with chronic knee pain and swelling, related to activity and resistant to non-operative treatment, underwent diagnostic knee arthroscopy. In 3 cases diagnostic arthroscopy revealed osteochondral ulcers of the medial compartment of the knee managed by drilling and 4 cases showed non-specific synovitis managed by arthroscopic synovectomy. 30 of these patients, who were included in this study, were found to suffer from partial ACL tear and underwent single bundle reconstruction, 18 of them underwent selective AM bundle reconstruction while preserving PL bundle. Twelve patients underwent selective PL bundle reconstruction with AM bundle preservation. Semitendinosus tendon graft was utilized for all reconstructions. The femoral side was always fixed with an adjustable loop (Zimmer), and the tibial side with a biodegradable interference screw. Lysholm score[4] was used to assess the outcomes. Patients with severe degenerative disorders, lower limb mal-alignment and multiple ligamentous injuries of the knee were excluded from our study. Results: Marked decrease in the knee pain and swelling postoperatively. The preoperative score had a mean value of 66.17±10.39. At 2 years, the postoperative score was 96.1±6.71, indicating a highly statistically significant improvement (P value 0.001). Hypothesis: Partial ACL tears are the commonest hidden cause of pain and swelling of the knee among young adults. Conclusion: Arthroscopic selective bundle reconstruction diminishes knee pain and swelling with a very satisfactory postoperative clinical outcomes.

Overexpression of PRDM16 improves muscle function after rotator cuff tears

Muscle atrophy, fibrosis, and fatty infiltration are commonly seen in rotator cuff tears (RCTs), which are critical factors that directly determine the clinical outcomes for patients with this injury. Therefore, improving muscle quality after RCT is crucial in improving the clinical outcome of tendon repair. In recent years, it has been discovered that adults have functional beige/brown adipose tissue (BAT) that can secrete batokines to promote muscle growth. PRDM16, a PR-domain-containing protein, was discovered with the ability to determine the brown fat cell fate and stimulate its development. Thus, the goal of this study was to discover the role of PRDM16 in improving muscle function after massive tendon tears using a transgenic mouse model with an elevated level of PRDM16 expression. Transgenic aP2-driven PRDM16-overexpressing mice and C57BL/6J mice underwent unilateral supraspinatus (SS) tendon transection and suprascapular nerve transection (TTDN) as described previously (n=8 in each group). DigiGait was performed to evaluate forelimb function at 6 weeks post the TTDN injury. Bilateral SS muscles, interscapular brown fat, epididymal white fat, and inguinal beige fat were harvested for analysis. The expression of PRDM16 in adipose tissue was detected by Western blot. Masson Trichrome staining was conducted to evaluate the muscle fibrosis, and Oil Red O staining was used to determine the fat infiltration. Muscle fiber type was determined by major histocompatibility complex (MHC) expression via immunostaining. All data were presented in the form of mean±standard deviation. t test and 2-way analysis of variance was performed to determine a statistically significant difference between groups. Significance was considered when P<.05. Western blot data showed an increased expression of PRDM16 protein in both white and brown fat in PRDM16-overexpressing mice compared with wild-type (WT) mice. Even though PRDM16 overexpression had no effect on increasing muscle weight, it significantly improved the forelimbs function with longer brake, stance, and stride time and larger stride length and paw area in mice after RCT. Additionally, PRDM16-overexpressing mice showed no difference in the amount of fibrosis when compared to WT mice; however, they had a significantly reduced area of fatty infiltration. These mice also exhibited abundant MHC-IIx fiber percentage in the supraspinatus muscle after TTDN. Overexpression of PRDM16 significantly improved muscle function and reduced fatty infiltration after rotator cuff tears. Promoting BAT activity is beneficial in improving rotator cuff muscle quality and shoulder function after RCT.

Enhancing Structural Performance of Recycled Aggregate Concrete using Coconut Fiber: A Quantitative Analysis

Natural fibers are gaining attention for their benefits in both artificial and natural contexts. Using natural fibers in reinforced composites can reduce dependency on conventional concrete-making materials and mitigate environmental impact. This paper examines the effect of coconut fibers on the compressive strength of recycled aggregate (RA) concrete, focusing on the development of sustainable and ductile cementitious composites through the optimization of coconut fibers and construction waste. Specifically, the study investigates the impact of different percentages of coconut fiber (0%, 3%, 5%, and 7% by volume of the mix) on the compressive strength of concrete incorporating varying amounts of RA (0%, 25%, 50%, 75%, and 100%). The performance of these mixes was evaluated based on workability, density, and compressive strength (CS). The results showed that as the amount of RA increased, compressive strength decreased. To regain maximum strength, a preferable amount of 5% coconut fibers is required for each constant level of the water-cement ratio. Concrete incorporating 25% coarse RA with 5% coconut fibers exhibited compressive strength comparable to conventional concrete. The highest compressive strength for concrete made using 50% coarse RA with 0.3 water-cement ratio was achieved with 5% coconut fibers. This study recommends using 5% coconut fibers to attain optimal mechanical performance. The main scope of this paper highlights the potential use of coconut fibers in fibrous composites to partially replace conventional materials.