Reduction In Strength Research Articles

Experimental analysis on Self Compacting Concrete by using Nano - Silica Gel

Abstract: Self-Compacting Concrete (SCC) has gained widespread recognition in modern construction due to its ability to flow under its weight, eliminating the need for mechanical vibration. Despite its numerous advantages, challenges such as maintaining stability, durability, and achieving optimal mechanical performance persist. Incorporating nano-silica gel, a material known for its high pozzolanic activity and micro-filling capability, offers a promising solution to address these challenges. This experimental study evaluates the impact of nano-silica gel on the fresh, mechanical, and durability properties of SCC. The research involves preparing SCC mixes with varying nano-silica gel dosages (0.5%, 1%, 1.5%, and 2% by weight of cement) and analyzing their performance through a series of standardized tests. Fresh properties such as slump flow, T500 flow time, and V-funnel tests are used to assess workability and flow characteristics. Hardened properties, including compressive strength, split tensile strength, and flexural strength, are evaluated at different curing ages. Durability is analyzed through Rapid Chloride Penetration and Sulfate Resistance tests to assess the resistance to chemical attacks. Results indicate that the inclusion of nano-silica gel significantly enhances the flowability, compressive strength, and durability of SCC. The optimal performance is observed at 1% nano-silica gel dosage, beyond which a reduction in workability and strength occurs due to increased particle agglomeration. This study demonstrates that nano-silica gel can substantially improve SCC properties, making it a viable material for high-performance and sustainable construction practices. These findings contribute to the ongoing development of advanced concrete technologies, paving the way for future research in optimizing SCC mixes with nano-materials.

Feasibility of coal bottom ash as fine aggregate in strain-hardening cementitious composites: A study on strength, durability, and sustainability

The search for cost-effective and sustainable materials for strain-hardening cementitious composites (SHCC) has led researchers to explore alternatives to silica sand, a critical yet costly and environmentally unfavorable material. Although river sand seems like a cheaper and viable alternative, its extraction is linked to severe environmental degradation. This study aims to investigate the potential of coal bottom ash (CBA) as a replacement for silica sand in SHCC, targeting to meet the minimum requirements for structural applications. The novelty of this research lies in its comprehensive exploration of CBA as a partial to full replacement for silica sand (at 0 %, 25 %, 50 %, 75 %, and 100 %), extending beyond the replacement limit investigated in previous studies on SHCC, and provides an extensive evaluation of the composite’s fresh, mechanical, durability, and microstructural properties. Additionally, it includes a thorough assessment of the leaching potential, CO₂ emissions, energy consumption, and cost implications of the CBA-SHCC, which have not been fully explored in earlier CBA-SHCC research. The findings indicate that the reduction in mechanical strength was minimal (0.5 %-10 %) across all CBA replacement levels. Notably, all mixes demonstrated typical strain-hardening behavior, sustaining higher flexural loads beyond the first crack, with increased deflection capacity observed at higher CBA contents, peaking at 50 % replacement. Durability metrics, including water absorption and HCl acid attack resistance, exhibited a downward trend with higher CBA content but remained within acceptable limits up to 75 % replacement. Toxicity characteristic leaching procedure results confirmed the non-leachability of toxic elements in both the CBA and CBA-SHCC mixes. Economically and environmentally, CBA proved advantageous, resulting in 1.5–5 % lower CO2 emissions, 0.4–1.5 % lower energy consumption, and 18–84 % cost savings at 25–100 % CBA replacement. Additionally, a multicriteria analysis using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was employed, which identified 25 % as the optimal CBA content that balances fresh properties, mechanical strength, durability, environmental sustainability, and cost efficiency. The study is significant because it demonstrated that CBA can be used as a sustainable and cost-effective alternative to silica sand in SHCC, with lower environmental impact while maintaining structural integrity.

Efficient Load-Bearing Capacity Assessment of a Degraded Concrete Manhole Using Sectional Homogenization

This study addresses a practical and efficient approach to evaluating the load-bearing capacity of severely degraded concrete manholes. Concrete deterioration, often advanced and highly irregular, can be captured accurately through surface scanning to create a detailed model of the damaged structure and also to build a simplified modeling to enable rapid engineering-level assessment, filling a critical gap in infrastructure maintenance. The repair strategy involves applying an internal polyurea layer, a variable-thickness polyurethane foam layer depending on the degree of localized degradation, and an external polyurea layer to restore the original shape of the manhole. However, these repairs do not fully restore the manhole’s original load-bearing capacity. A full 3D model, encompassing millions of finite elements, would provide a detailed analysis of strength reductions but is impractical for engineering applications due to computational demands. An alternative approach utilizing sectional homogenization is proposed, where sectional properties are sequentially averaged to calculate effective parameters. This approach enables the use of only a few hundred shell elements, each representing thousands of elements from the detailed 3D model, thus providing a rapid, engineering-level assessment of load-bearing reductions in degraded manholes. The study finds that while the repair method restores up to 76% of bending stiffness in heavily corroded sections, it does not fully recover the original load-bearing capacity.

Are Dental Prophylaxis Protocols Safe for CAD-CAM Restorative Materials? Surface Characteristics and Fatigue Strength

The surface of dental materials is exposed to various prophylaxis protocols during routine dental care. However, the impact of these protocols on the functional properties of the material’s surface remains unclear. This study investigates the influence of different dental prophylaxis protocols on the surface properties and their effect on the mechanical performance of CAD-CAM restorative materials. Discs (Ø = 15 mm, thickness = 1.2 mm) were fabricated from resin composite (RC, Tetric CAD), leucite-reinforced (LEU, IPS Empress CAD), lithium disilicate (LD, IPS e.max CAD), and zirconia ceramics (ZIR, IPS e.max ZirCAD MT). The materials were subjected to six prophylactic treatments: untreated (CTRL), prophylactic paste fine (PPF), prophylactic paste coarse (PPC), pumice stone (PS), air abrasion with sodium bicarbonate jet (BJ), and ultrasonic scaling (US). Biaxial flexural fatigue tests, along with fractographic, roughness, and topographic analyses, were conducted. No significant changes in fatigue strength were observed for RC, LD, and ZIR under any prophylaxis protocols. However, LEU subjected to BJ treatment exhibited significantly reduced fatigue strength (p = 0.004), with a 22% strength reduction compared to the monotonic test and substantial surface alterations. Surface roughness analyses revealed increased roughness for RC treated with PPF, PPC, and PS compared to CTRL (p < 0.05), while LD exhibited decreased roughness following PPF, PS, and US treatments (p < 0.05). In ZIR, only the BJ protocol increased roughness (p = 0.001). In conclusion, dental prophylaxis protocols do not significantly affect the mechanical strength of RC, LD, and ZIR materials, thus allowing any protocol to be used for these materials. However, for LEU ceramics, the BJ protocol should be avoided due to its effect of reducing fatigue strength and damaging the surface.

Insight into drilling performance parameters for in-situ detection of lithological transition

In order to examine the rock dependence on drilling performance parameters, such as torque and rate of penetration (ROP), we conducted laboratory drilling experiments using mafic and ultramafic rocks from the Oman ophiolite and the Horoman Complex. Serpentinized peridotite shows approximately twice the ROP (dry conditions: 2.95 ~ 3.85, wet conditions: 8.25 ~ 10.3 × 10−5 m/min) compared to that of peridotite and mafic samples (dry conditions: 4.75 ~ 6.90, wet conditions: 14.5 ~ 18.3 × 10−5 m/min) under both dry and wet conditions. This result is likely due to the reduction in fracture strength associated with serpentinization. We compared the laboratory results of drilling parameters with in situ data obtained from IODP Expedition 360 drilling of gabbro and Expedition 399 drilling of serpentinized peridotite, using the equivalent strength method to normalize ROP to the given rotation rate and torque. The calculation results show that the normalized ROP for the serpentinized peridotite formation was systematically higher than that for the gabbro layer, which is in agreement with our experimental results. We propose that the in situ drilling performance parameters can be used to detect the lithological transitions, such as serpentinite.

Structural Assessment Material and Fire Induced Strength Degradation Material of Multistory Building

This paper presents a detailed case study of a multistory building near Bombay Motors in Jodhpur that suffered severe fire damage, with temperatures reaching up to 900°C. The fire brigade arrived 30 minutes after the incident. Under the guidance of MBM University, research scholars conducted site investigations to analyze the impact of the fire on the building's materials, particularly concrete and reinforcement. The study reveals how the fire weakened these materials, leading to a significant reduction in the building's strength, especially in the columns. Notably, Floor 4 retained more strength than Floor 3, with strength differences ranging from +26.67% in one column to -20% in another. This highlights the variation in damage, indicating that while some columns on Floor 4 remained stronger, others experienced considerable strength loss. The findings emphasize the vulnerabilities exposed by fire and suggest ways to enhance building resilience. The research advocates for updates to building codes to incorporate better fire safety measures and provides valuable insights for improving firefighting and evacuation plans during emergencies. While the study is focused on this particular building, its results can also inform urban planning and fire risk management in other high-risk areas. By identifying weaknesses in design and materials, the study offers guidance for architects, engineers, and policymakers. Overall, the case study contributes to the goal of creating safer, stronger buildings in similar environments, promoting better construction practices and fostering safer cities. Additionally, the evaluation of residual strength was conducted using ISO 834 and Euro Code standards, and simulations performed through Abaqus software yielded results closely aligned with experimental techniques.

Development and characterization of PLA food packaging composite

AbstractThis study focuses on the development of bioactive packaging materials by incorporating grape pomace and copper particles into polylactic acid (PLA) composites. The goal is to increase the shelf life of packaged foods while benefiting the health of consumers through the use of these active materials. 6 recipes of composite materials based on polylactic acid and Proviplast 2624 plasticizer were obtained. The additives added were: grape pomace, added at 0.5%, 1% and 1.5%, and copper particles, formed using PEG 600 + CuSO₄, added at 2%, 5% and 8%. Material characterization techniques: FTIR Spectroscopy, used to study the chemical structure. Differential scanning calorimetry (DSC): examined thermal transitions such as glass transition and melting temperatures. Thermogravimetric analysis (TGA) and differential thermogravimetry (DTG): evaluated thermal stability and degradation temperatures. Scanning electron microscopy (SEM) and atomic force microscopy (AFM): analyzed the surface morphology and structure. Mechanical tests: evaluated tensile strength, elongation at break and flexibility.Thermal property analyzes revealed that the additives acted as plasticizers, reducing the intermolecular forces between PLA chains, which decreased the glass transition temperature (Tg), cold crystallization temperature (Tcc) and melting temperature (Tm). The addition of grape pomace and copper particles decreased the degradation temperature of PLA composites, indicating a slight reduction in thermal stability. The transformation temperatures changed and the nature of the thermal transitions (exothermic or endothermic) varied with additive concentrations. Mechanical properties indicated a reduction in tensile strength with increasing additive concentration. Elongation at break and longitudinal modulus of elasticity increased significantly, especially with grape pomace, improving the flexibility of PLA. These changes indicate that the material can absorb more energy before breaking, making it more ductile and more suitable for flexible packaging applications. Increased flexibility and improved thermal resistance ensure that these materials can withstand the demands of packaging, handling and shipping. The combination of improved flexibility, thermal resistance and moderate tensile strength makes these PLA-based composites incorporated with grape pomace or copper particles, enhance the aspect of sustainability by recycling agricultural waste, making the material both ecological and functional, making it a viable option for active food packaging.

Relationship of female pelvic floor muscle function and body composition: cross-sectional study.

Investigate the relationship between female pelvic floor muscle (PFM) function and body composition. Cross-sectional study-participants answered sociodemographic and urogynecological questions. The amount of fat mass was measured by dual-emission X-ray densitometry (DXA), and subcutaneous fat thickness was assessed by abdominal ultrasound. PFM assessment was performed using the Modified Oxford Scale and vaginal manometry. Descriptive analysis, independent t test, spearman correlation, and univariate regression were performed. Ninety-nine women were included. All body composition variables evaluated, except subcutaneous fat thickness, indicated that women with a higher concentration of fat in the pelvic, android, and visceral region have lower maximum voluntary PFM contraction strength assessed by Modified Oxford Scale and manometry. The univariate model pointed out that the fat concentration increases the chances of reduced PFM strength in the entire body (0.6%), android (5.4%), visceral region (25.3%), and pelvic (89.9%). There was a correlation between the concentration of total, pelvic, and android fat with MVC/average peak. The accumulation of "total", "pelvic", "android", and "visceral" fat mass is correlated with reduction in PFM strength, and there is an association between MVC and the variables of total and segmented fat. However, pelvic fat concentration is predictive in 89.9% of cases.

Flexural and low‐velocity behavior of GFPP/DP980 honeycomb sandwich structure inspired by fiber metal laminates

AbstractWith the rapid development of electric vehicles, a hybrid composite structure has been designed for the battery pack bottom guard to enhance impact resistance and reduce weight. The glass fiber‐reinforced polypropylene (GFPP)/DP980 honeycomb sandwich structure consists of GFPP panels with a polypropylene honeycomb core. DP980 advanced high‐strength steel plate is encapsulated within the structure, inspired by fiber metal laminates. A lightweight and high‐strength sandwich composite lay‐up solution was determined through equivalent bending stiffness theory, finite element simulation and experiment. An asymmetric sandwich structure with the steel plate on the impacted side enhanced flexural strength and ductility, demonstrating different failure sequences and a higher bending strength of 77.64 MPa compared to 50.18 MPa when the steel plate was on the unimpacted side. As impact energy increased from 100 to 200 J, the sandwich structure showed higher peak impact load, deeper craters, and increased bulge height, with significant delamination up to 175 J, while gravel impact tests revealed minimal flexural strength reduction (4.92%) even after repeated impacts. This study confirms that the use of thermoplastic sandwich structures is a viable and promising option for crash safety and the lightweight design of battery pack bottom guards.Highlights The thermoplastic honeycomb sandwich structure is polypropylene‐based. The use of advanced high strength steel is inspired by fiber metal laminates. Both thickness and surface density are considered in the structural design. The steel plate placed on the impacted side improves the flexural behavior. The sandwich structure has excellent impact resistance and lightweight level.

Investigating physical and mechanical properties of alumina/acrylonitrile butadiene styrene composites manufactured by fused deposition modeling

AbstractIn recent years, 3D printing technologies or additive manufacturing have gained significant attention in research and other industries. Among the various 3D printing techniques, fused deposition modeling has been the most widely adopted. This study focused on developing composite filaments by incorporating acrylonitrile butadiene styrene (ABS) with different volume percentages of aluminum oxide (alumina). The mechanical and physical properties of parts printed with these composite filaments were thoroughly evaluated. Tensile testing revealed that increasing the alumina content led to a reduction in tensile strength. At 20 vol%, tensile strength dropped by 72%. A heat deflection temperature (HDT) test indicated an 11% reduction in HDT, likely due to the defective composite structure. Thermogravimetric analysis test demonstrated improved thermal stability as alumina content increased. Linear shrinkage was measured in three directions, revealing anisotropic shrinkage patterns. Hardness tests were conducted, and a decrease was observed when the polymer was filled with alumina. Finally, the warpage was reduced by 91% as alumina content increased to 20%.Highlights Alumina/ABS composite filaments were manufactured and 3D‐printed very well. The void content in composite samples increases with alumina powders. The mechanical properties of 3D‐printed composite parts were decreased The alumina powder improves the warpage issues in 3D‐printed parts.

Numerical Investigation and Cross‐Section Type Selection of Concrete‐Filled Double Steel Plate (CFDSP) Composite Shear Walls Under Cyclic Loading

ABSTRACTConcrete‐filled double steel plate (CFDSP) composite shear walls have excellent seismic performance and are generally used as lateral resistance for high‐rise buildings. However, the numerical simulation of such walls is complicated because of the complex contact between the concrete, the external steel plate, and the shear studs. Eighteen CFDSP walls in the present literature were numerically simulated under cyclic and constant axial loading, and the accuracy was evaluated by comparing them with the experimental results. Then, the impact of cross‐section variations on the structural performance of CFDSP walls under the same steel content ratio was numerically investigated. Designed numerical walls were evaluated under the same loading conditions with four distinct cross‐sections for comparative analysis. Finally, parametric analysis was performed to observe the influence of aspect ratio, steel thickness, and stud spacing on the seismic performance of CFDSP walls. The analysis results show that the proposed numerical model can accurately recover the hysteretic curves of CFDSP walls regarding strength reduction, energy dissipation, and pinch behavior.

Research on Key Parameters of Wellbore Stability for Horizontal Drilling in Offshore Hydrate Reservoirs

The South China Sea has abundant reserves of natural gas hydrates, and if developed effectively, it can greatly alleviate the pressure on the energy supply in China. But the hydrate reservoirs in the sea area are loose, shallow, porous, and have poor mechanical properties. During the drilling process, the invasion of drilling fluid into this kind of reservoir is likely to induce mass decomposition of gas hydrate and, in turn, a significant reduction in mechanical strength around the wellbore as well as instability of the wellbore. In this study, in light of the engineering background of exploratory wells at the South China Sea, a temperature and pressure field model in a gas hydrate reservoir at sea during open circuit drilling was established, and then, based on this model, a comprehensive model for the stability analysis of the well drilled in the hydrate reservoir at sea was constructed, both of them with errors of less than 10%. With these two models, the effects of different drilling parameters on wellbore stability were investigated. The gas and liquid produced by the decomposition of hydrates in the formation will increase the pore pressure in the formation, thereby reducing the effective stress in the formation. The closer the formation is to the wellbore, the more thorough the decomposition of hydrates in the formation and the greater the effective plastic strain. Keeping all other conditions constant, the increase in drilling fluid invasion pressure and temperature, as well as reservoir permeability, will lead to a decrease in the mechanical strength of the formation around the wellbore and an expansion of the wellbore yield zone. The results can provide a theoretical reference for the stability analysis at sea.

Waste Polyethylene Terephthalate (PET) as a Partial Replacement of Aggregates in Sustainable Concrete

Concrete use is enhanced daily due to infrastructure development, but it has adverse impacts on the environment. Modern lifestyles have led to the increased use of plastic, and, for households, polyethylene terephthalate (PET) plastics are used. However, PET is non-biodegradable and causes adverse impacts on the environment and marine health. So, there is a need to minimize the amount of plastic waste by finding an alternative use for the waste. Our study focuses on creating sustainable concrete by utilizing PET-based plastic waste as a partial substitution for aggregates, aiming to use this concrete for various low-load-bearing construction applications. From our phase analysis study, no adverse effects were found on cement phase formation. We also found that up to 10 wt.% PET incorporation leads to acceptable compressive strength reduction as per ASTM guidelines. To enhance adhesion, the PET was roughened, and, from FESEM, we found effective adhesion of PET waste into the cement matrix. We believe that this sustainable concrete will not only contribute to waste reduction but also promote eco-friendly construction material development.

Cracking Sensitivity Analysis of Red Clay With Pre‐Crack Under Three‐Point Bending

ABSTRACTRed clay is highly susceptible to cracking due to its nature, and the reduction in strength caused by cracking can lead to engineering disasters. To investigate the cracking sensitivity of red clay, a homogeneous fracture model of red clay based on the cohesive zone model was established using ABAQUS in this work, the reliability of the model was verified through a three‐point bending test, and then the crack propagation process and sensitivity to test factors of red clay were further analyzed. The results show that the fracture simulation of the cohesive zone model is in good agreement with the test results, confirming by the high reliability. The depth of prefabricated cracks and fulcrum spacing had the significant effects on the crack path, and the decrease of prefabricated crack depth and fulcrum spacing led to the increase of critical load. Meanwhile, the loading rate had little effect on the load–displacement curves.

Epidermal growth factor receptor contributes to indirect regulation of skeletal muscle mass by androgen.

Androgen is widely acknowledged to regulate skeletal muscle mass. However, the specific mechanism driving muscle atrophy resulting from androgen deficiency remains elusive. Systemic androgen receptor knockout (ARKO) mice exhibit reduction in both muscle strength and muscle mass while skeletal muscle fiber specific ARKO mice have decreased muscle strength without affecting skeletal muscle mass in the limbs. Therefore, androgens may indirectly regulate skeletal muscle mass through effects on non-myofibers. Considering this, our investigation focused on blood fluid factors that might play a role in the regulation of skeletal muscle mass under the influence of androgens. Using a male mouse model of sham, orchidectomy and DHT replacement, mass spectrometry for serum samples of each group identified epidermal growth factor receptor (EGFR) as a candidate protein involving the regulation of skeletal muscle mass affected by androgens. Egfr expression in both liver and epididymal white adipose tissue correlated with androgen levels. Furthermore, Egfr expression in these tissues was predominantly elevated in male compared to female mice. Interestingly, male mice exhibited significantly elevated serum EGFR concentrations compared to their female counterparts, suggesting a connection with androgen levels. Treatment of EGFR to C2C12 cells promoted phosphorylation of AKT and its downstream S6K, and enhanced the protein synthesis in vitro. Furthermore, the administration of EGFR to female mice revealed a potential role in promoting an increase in skeletal muscle mass. These findings collectively enhance our understanding of the complex interplay among androgens, EGFR, and the regulation of skeletal muscle mass.

Effect of hygrothermal ageing on the mechanical properties of glass fiber reinforced polymer composite: Experimental and numerical approaches

This paper studied the effect of hygrothermal ageing on the mechanical performance of glass fiber-reinforced polymer composites (GFRPCs), a crucial material for marine applications due to its lightweight and superior resistance to environmental chemicals. However, prolonged exposure to moisture and temperature can degrade its properties, impacting structural integrity. The influence of moisture diffusion in GFRP composite laminates was evaluated by accelerated ageing tests, which involved submerging the composite laminate in seawater at 75°C until it reached full saturation. The composite laminates were fabricated with weight fractions of glass fiber reinforcements 55 %, 60 %, and 65 %. After two months of submersion, mechanical characteristics, namely tensile strength, modulus of elasticity, and interlaminar shear strength (ILSS) were investigated. A computational model was developed using COMSOL Multiphysics to analyse the coupled interfaces of moisture diffusion and heat. The failure mechanism of the GFRP composites was analysed using a scanning electron microscope (SEM). After two months of submersion, the moisture uptake data for the tension test samples showed a maximum saturation of 3.45 % for the 55 % fiber weight fraction, leading to a reduction in tensile strength from 269 MPa to 171 MPa and in modulus of elasticity from 24 GPa to 21 GPa. For the ILSS test samples, the maximum moisture saturation was 2.95 % for the 55 % fiber weight fraction, with a corresponding decrease in ILSS from 24 MPa to 21 MPa. However, increasing the glass fiber weight fraction from 55 % to 65 % resulted in improved tensile strength, modulus of elasticity, and ILSS in both as-manufactured and aged samples. The results of simulations and experiments showed that hygrothermal ageing causes the fiber surface to debond and causes matrix cracking, which in turn creates an uneven internal stress field.

Genetic factors associated with changes in muscle strength and mass during corticosteroid therapy

BACKGROUND: Corticosteroid use is associated with loss of muscle mass and strength, which is associated with an unfavorable prognosis of the underlying disease, as well as an increased risk of cardiovascular disease. Patients with multiple sclerosis (MS) have a higher baseline susceptibility to cardiovascular disease and a higher risk of adverse effects due to corticosteroid use. In clinical practice, different degrees of severity of side effects of corticosteroids are reported. This may be related to the presence of a genetic predisposition, the identification of which should allow a personalized approach to therapy. AIM: To evaluate the association of polymorphic variants of the glucocorticoid receptor gene NR3C1, the FTO gene, and the melatonin receptor genes MTNR1A, MTNR1B with the development of changes in muscle mass and strength in the context of corticosteroid use in patients with MS. MATERIALS AND METHODS: The study included 80 patients (mean age 36.3±10.0 years) with MS receiving pulse corticosteroid therapy: 4 (3; 4) g methylprednisolone. Patients were enrolled over the course of one year. To assess the primary endpoint (reduction in muscle mass and strength), muscle strength and mass were monitored before and after therapy using wrist dynamometry, the time-up-and-go test, and bioimpedancemetry. Polymorphic variants of the glucocorticoid receptor gene NR3C1, the FTO gene, and the melatonin receptor genes MTNR1A and MTNR1B were identified by real-time polymerase chain reaction. Intergenic interactions were evaluated using the multifactor dimensionality reduction (MDR) method. R (v. 3.2, R Foundation for Statistical Computing, Austria) was used for statistical analysis. RESULTS: In women with loss of muscle mass after corticosteroid therapy, there was an increased incidence of depression (p=0.01) for polymorphic variant BclI (rs41423247) of the NR3C1 gene (p=0.005). Reduced dominant arm strength in women was associated with a variant of the BclI gene (rs41423247) (p=0.02), genotypes including BclI (rs41423247) and N363S (rs56149945) (p=0.03). Men with decreased strength in the non-dominant arm were more likely to be smokers (p=0.03). Combinations of genotypes of the NR3C1, FTO, MTNR1B genes were identified with increased and decreased risk of muscle mass loss in women after corticosteroid therapy. Analysis of intergenic interactions showed a strong synergism between the polymorphic variant rs993960 of the FTO gene and rs10830963 of the MTNR1B gene. CONCLUSION: The presence of polymorphic variants BclI (rs41423247), N363S (rs56149945) of the glucocorticoid receptor gene NR3C1 is associated with loss of muscle strength and mass in women receiving corticosteroid therapy for MS. Combinations of genotypes of the NR3C1, FTO, MTNR1B genes have been identified with an increased risk of muscle mass loss in women after corticosteroid therapy. Modifiable factors associated with loss of muscle mass and strength and cardiovascular risk (depression, smoking) were identified. The data obtained can be used to personalize corticosteroid therapy and prevent cardiovascular and metabolic disorders.

Dough properties and baking quality of near isogenic lines with single HMW-GS null at Glu-A1, Glu-B1 and Glu-D1 loci in soft wheat

High molecular weight glutenin subunits (HMW-GSs) encoded by the Glu-1 loci are key factors in determining wheat processing quality. However, the contributions of single HMW-GS to dough viscoelastic properties and end-use quality have not been well understood, especially in soft wheat. In this study, the kernel samples of five Near Isogenic Lines (NILs) of a soft wheat each with individual HMW-GS null were investigated. Significant lower SDS-sedimentation volume and lactic acid solvent retention capacity (SRC) were observed in the NILs, compared to the wild type (WT). Except for the NIL with Glu-D1y12 null, the other NILs were associated with significantly lower dough mixing tolerance compared to the WT. Also, the deletion of individual HMW-GS was associated with reduction in dough elasticity and strength, compared to the WT, with the exception of the Glu-A1x1 null. Moreover, Glu-B1x7 was the most important HMW-GS in determining dough mixing tolerance and elasticity. Compared to the WT, the deletions of Glu-D1x2, Glu-B1x7 and Glu-B1y8 significantly increased alveograph L, and decreased alveograph P and P/L ratios. All NILs with single HMW-GS null showed better sugar snap cookie baking quality than the WT. New germplasm and tools are identified for improving dough viscoelasticity and baking quality in soft wheat.

Durability assessment of ultra-high-performance concrete (UHPC) and FRP grid-reinforced UHPC plates under marine environments

Fiber reinforced polymer (FRP) reinforced ultra-high-performance concrete (UHPC) structures not only tackle the issue of insufficient stiffness encountered in FRP reinforced normal concrete structures, but also offer a promising solution to address the durability challenges present in conventional reinforced concrete structures. While some studies have explored the mechanical properties of FRP reinforced UHPC (referred to as FRU), their durability performance remains unexplored. This paper presents a comprehensive durability assessment of FRU and UHPC plates, incorporating steel and polyethylene (PE) fibers, to compare their performance under simulated marine conditions, along with a durability evaluation of the corresponding UHPC cylinders and FRP grid samples. Tensile retention strengths of UHPC and FRU plates were evaluated after exposure. Scanning electron microscope (SEM) analyses were employed to examine fracture surfaces. The results indicate that carbon FRP (CFRP) grids significantly enhanced the tensile performance of UHPC, showcasing improvements in tensile strength, multiple-cracking, and strain-hardening behaviors. Seawater exposure led to evident reductions in the tensile strength of UHPC plates, particularly those incorporating steel fibers. Conversely, FRU plates exhibited much smaller decreases, especially those reinforced with polyethylene (PE) fibers. This study highlights the suitability of FRU reinforced with PE fibers for marine infrastructures.

Imperfection-insensitive flexible random network materials with horseshoe microstructures

Flexible network materials with periodic constructions of bioinspired wavy microstructures are of focusing interest in recent years, because they combine outstanding mechanical performances of low elastic modulus, high stretchability, biomimetic stress-strain responses, and strain-limiting behavior. In practical applications (e.g., bio-integrated devices and tissue engineering), small holes are often strategically designed in flexible network materials to accommodate functional chips and other individual electronic components. The design of imperfection insensitive flexible network materials is therefore of pivotal importance. While random structural constructions are believed to play crucial roles in the excellent mechanical properties of many biological materials, the effect of randomness on mechanical performances of flexible network materials has not yet been explored. In this work, a class of two-dimensional (2D) flexible random network materials consisting of horseshoe microstructures is introduced. Their node distance distributions, which can be characterized by a parameter related to randomness, follow well the Weibull probability density function. Combined numerical and experimental studies were performed to elucidate the effect of randomness on nonlinear mechanical responses of flexible network materials. Simple analytical equations are obtained for their key mechanical properties (e.g., strength, stretchability, and initial modulus). Flexible random network materials (with randomness ≥ 0.4) were found to exhibit approximately isotropic J-shaped stress-strain responses, even in the high-strain regime. Finally, we study the reduction of stretchability and strength in random network materials induced by different types of imperfections (e.g., a missing filament, a missing node, or many missing filaments). In comparison to periodic network materials, random network materials (e.g., with randomness ≥ 0.6) show much smaller reductions of stretchability/strength when the imperfection appears, and are therefore more imperfection-insensitive. Such an imperfection-insensitive behavior can be mainly attributed to a relieved stress concentration around the imperfection of random network materials.