Search Results (5,022)

To explore the application of precast concrete construction methods in underground stations, a combined precast and cast in situ construction method was adopted for a long-span column-free underground subway station. To study the stability of large-span underground arch structures under asymmetric loading, a full-scale test was conducted using the displacement-force control method. Steel blocks were used to simulate the overlying soil and additional loads on the upper surface of the arch, while the displacement of the arch foot was applied by adjusting the tension of the cables. The maximum tensile stress and maximum compressive stress of the steel bars appeared at the midpoints of the left and right arches, which were less than the yield stress of the steel bars. The results show that the structural stability meets the design requirements and provides a considerable safety margin. A comprehensive analysis of the arch structure under asymmetric loading was carried out through on-site monitoring, numerical simulation, and analytical solutions. The results are in good agreement: compared with the experimental results, the calculated values increase the maximum deflection of the arch by 13.67%, which verifies the reliability of the numerical simulation and analytical solution methods under the same boundary conditions. However, restricted by test conditions, the loading in this study was only applied on one side of the arch crown, which differs from the actual working condition involving full loading first followed by unloading on one side. Full article

A critical aspect in the design of power electronics packages is the prediction of their mechanical response under severe thermomechanical loads and the consequent structural damage. For this purpose, finite element (FE) simulations are used to estimate the mechanical performance and reliability under operational conditions, typically alternate high voltages/currents resulting in thermal gradients. When simulations are performed, it is common practice to consider the as-received package to be in a stress-free state. Namely, residual stresses and plastic deformation induced by the manufacturing processes are neglected. In this study, an advanced FE modeling approach is proposed to assess the structural consequences of the encapsulating resin curing, typical in the production of silicon carbide (SiC)-based power electronics modules for electric vehicles. This work offers a general modeling framework that can be further employed to simulate the effects of thermal gradients induced by the production process on the effective shape and residual stresses of the as-received package for other manufacturing stages, such as metal brazing, soldering processes joining copper and SiC, and, to lower extents, the application of polyimide on top of passivation layers. The obtained results have been indirectly validated with experimental data from literature. Full article

Offshore platforms need to be made, from the start of their construction, to withstand the extreme environmental conditions they will be facing. This study investigates the welding-induced residual stress and distortion in a Y-shaped tubular joint extracted from an offshore wind turbine jacket substructure. While similar joints are commonly used in offshore platforms, their welding behavior remains underexplored in the existing literature. The joint configuration is representative of critical load-bearing connections commonly used in offshore platforms exposed to harsh marine environments. A finite element model has been developed to simulate the welding process in a typical offshore tubular joint through thermal and mechanical simulation. Validation of the model has been achieved with results against reference experimental data, with temperature and distortion errors of 3.9 and 5.3%, respectively. Residual stress and distortions were analyzed along predefined paths in vertical, transverse, and longitudinal directions. A mesh sensitivity study was conducted to balance computational efficiency and result accuracy. Furthermore, clamped and free displacement boundary conditions are analyzed, demonstrating reduced deformation and stress for the second case. Full article

We consider an axysimmetric cylindrical vessel grown by surface deposition at the inner boundary. The residual stress in the vessel can vary, e.g., depending on the loading history during growth. Can we represent and characterize a stress-free material (namely, reference) configuration for the vessel? Extending an idea initially proposed for surface growth occurring on a fixed boundary, the material configuration is introduced as a two-dimensional manifold immersed in a three-dimensional space. The problem is first formulated in fairly general terms for an incompressible neo-Hookean material in plane strain and then specialized to material configurations represented by ruled surfaces. An illustrative example using geometric and material parameters of carotid arteries shows the characterization of different material configurations based on their three-dimensional slope and computes the corresponding residual stress fields. Finally, such a slope is shown to be in a one to one relationship with the customary measure of residual stress in arteries, i.e., the opening angle in response to a cut. The present work introduces a novel framework for residual stress and shows its applicability in a special setting. Several generalizations and extensions are certainly necessary in the following sections to further test and assess the proposed method. Full article

This study examines the forced vibration behavior of a hydroelastic system composed of a functionally graded material (FGM) plate, a barotropic compressible Newtonian viscous fluid, and an adjacent rigid wall. The fluid occupies the gap between the plate and the wall. A time-harmonic force, applied in and along the free surface of the FGM plate, excites vibrations within the system. The plate’s motion is modeled using the exact equations of elastodynamics, while the fluid dynamics are described by the linearized Navier–Stokes equations for compressible viscous flow. The governing equations, which feature variable coefficients, are solved using a discrete analytical approach. Boundary conditions enforce impermeability at the rigid wall and continuity of both forces and velocities at the fluid–plate interface. The investigation focuses on the plane strain state of the plate coupled with the corresponding two-dimensional fluid flow. Numerical analyses are conducted to evaluate normal stresses and velocity distributions along the interface. The primary objective is to assess how the graded material properties of the plate influence the frequency-dependent responses of stresses and velocities at the plate–fluid boundary. Full article

Oxidative stress plays a critical role in the development of various chronic diseases, leading to major health problems worldwide. There has been increasing interest in using natural antioxidants as complementary agents for maintaining redox homeostasis and assuring a healthy lifestyle. This study aimed to systematically screen the antioxidant potential and cytotoxicity profiles of 19 plant-derived extracts using both a cell-free Fenton reaction-based assay and human monocytic THP-1 cells in vitro. The radical-scavenging capacity varied markedly among the extracts, with Acalypha virginica Linnaeus (ACALYPHA), Acorus calamus Linnaeus (ACORUS), Actinidia deliciosa (A.Chev.) C.F. Liang & A.R. Ferguson (ACTINIDIA), and Heuchera sanguinea Pursh (HEUCHERA) demonstrating strong activity in the chemical assay. In the cellular model, 15 extracts significantly reduced intracellular reactive oxygen species (ROS) levels without inducing cytotoxicity at effective concentrations. Notably, Acalypha virginica Linnaeus (ACALYPHA), Actinidia deliciosa (A.Chev.) C.F. Liang & A.R. Ferguson (ACTINIDIA), Dianthus superbus Linnaeus subsp. superbus (DIANTHUS), Succisa pratensis Moench (SUCCISA), and Typha laxmannii Lepech (TYPHA) exhibited consistent antioxidant efficacy across multiple doses. At higher concentrations, all extracts triggered apoptosis and/or necrosis, emphasizing the importance of defining safe ranges. These findings provide a comprehensive comparative analysis of Mediterranean plant-based natural antioxidants obtained by an in vitro approach. The selected plant extracts could be considered as promising candidates for the development of strategies targeting oxidative stress-related disorders. Further investigations considering the specific phytochemical composition of each extract and in vivo validation are needed to confirm their efficacy and safety. Full article

Mycotoxin contamination represents a major risk to both human and animal health. Antioxidants can mitigate some of these effects through free radical scavenging, reduction in oxidative stress, and anti-inflammatory and immunomodulatory actions. This work investigated the potential of antioxidants derived from grapeseed and sea buckthorn to mitigate the adverse effects of aflatoxin B1 (AFB1) and ochratoxin A (OTA) in weaned piglets. An unbiased Data-Independent Acquisition (DIA) proteomic approach was used to analyse the impact of OTA- and AFB1-contaminated diets on liver and kidney cytoplasmic metabolism, particularly focusing on the conjugation phase. Our results indicate that several toxic effects of these mycotoxins were partially alleviated by dietary antioxidant supplementation. Additionally, in kidneys, some of the effects are synergistically amplified, such as proteins involved in fatty acid degradation, peroxisome, PPAR signalling, translation, the TCA cycle, and excretion pathways. Inclusion of antioxidants in the animal diet can have beneficial effects. Nevertheless, caution is advised; synergistic effects can occur with potentially more serious consequences than the effects of mycotoxins alone. Full article

Fluoride is a widespread environmental toxin that disrupts metabolic and endocrine functions, but its impact on pancreatic inflammation and hormone secretion remains unclear. This study examined how chronic fluoride exposure affects pancreatic inflammation and secretory function in rats. Pregnant Wistar rats received sodium fluoride (NaF) at 50 mg/L in drinking water during gestation and lactation. Male offspring continued exposure until 3 months old. Controls received fluoride-free water. Pancreatic tissue and serum were collected. Fluoride levels were measured potentiometrically. Eicosanoids were quantified by SPE and HPLC. Serum insulin, glucagon, and somatostatin were measured by ELISA. Histological and biochemical markers of inflammation and oxidative stress were assessed. Fluoride exposure did not lead to significant accumulation in the pancreas or serum. However, fluoride-exposed rats exhibited a significant decrease in serum insulin and somatostatin concentrations, while glucagon levels remained unchanged. Additionally, the pancreas of fluoride-treated animals showed markedly elevated levels of pro-inflammatory eicosanoids, including prostaglandin E2, leukotrienes A4 and B4, and HETE/HODE derivatives, indicating activation of cyclooxygenase and lipoxygenase pathways. Sustained low-dose fluoride exposure induced pancreatic inflammation and disrupted endocrine homeostasis in rats. These findings suggest that chronic fluoride intake may impair insulin secretion and promote pre-diabetic alterations, warranting further research. Full article

Postovulatory aging (POA) significantly contributes to fertility decline, primarily through oxidative stress, which impairs oocyte quality, reduces embryonic developmental competence, and may adversely affect offspring health. Edaravone (EDA), a potent free radical scavenger, is known for its cytoprotective effects in various disease models. This study aimed to evaluate whether EDA can mitigate the detrimental effects of POA on mouse oocyte and embryo quality and confirm its reproductive safety. Supplementation with 10 nM EDA significantly reduced meiotic abnormalities, restored mitochondrial distribution, enhanced mitochondrial membrane potential and ATP production, and decreased intracellular reactive oxygen species (ROS) in aged oocytes. Although EDA did not markedly improve fertilization or blastocyst formation rates, it enhanced embryo quality, with morphokinetic parameters comparable to those of young oocytes. Moreover, F₁ offspring derived from embryos produced by EDA-treated POA oocytes were healthy, and female progeny exhibited normal reproductive competence. These findings demonstrate that EDA safely improves oocyte quality by alleviating POA-induced oxidative damage, offering a potential antioxidant strategy to enhance assisted reproductive technology (ART) outcomes when applied to IVF clinics. Full article

This review examines the effects of oxidative stress on the aging process in canines, focusing on the role of antioxidants in the prevention of age-related diseases. Oxidative stress is caused by an imbalance between the production of free radicals and the body’s antioxidant defenses, resulting in damage to cell structures. Dogs, especially older animals, are particularly susceptible to such damage, which contributes to the development of cognitive impairment, chronic disease and a reduced quality of life. Antioxidants such as vitamins C and E, coenzyme Q₁₀ and polyphenols play an important role in neutralizing free radicals and mitigating oxidative damage. Various studies confirm that these antioxidants can improve overall health, slow cognitive decline and reduce the risk of diseases such as osteoarthritis, cancer and heart disease. The results suggest that an appropriate diet supplemented with antioxidants can significantly contribute to a better quality of life for dogs. However, given that some studies report limited or no effects, additional long-term clinical trials are warranted to validate the reproducibility and degree of presented benefits. Full article

The present study examined the impact of adding methionine (Met) and its conjugated form (Met-Met) on Cornu aspersum snails. The primary focus was on the animals’ growth performance, the chemical composition of their carcass (whole body without the shell), the mineral profile, and the mechanical properties of their shells. In two experiments conducted under controlled laboratory conditions, diets supplemented with varying levels of Met addition (0.3, 0.6, 1.4 g/kg feed) were used, and the effects of free methionine, Met-Met and their mixture (1.4 g/kg feed) were compared. The study incorporated measurements of body weight, shell width, and mortality of snails. Analyses encompassing protein, fat, sulphur amino acids, glutathione levels, oxidative stress indices (DPPH, TAC, TBARS), and macro- and micronutrient content of carcass and shells were conducted. The findings demonstrated that adding 1.4 g Met/kg feed significantly enhanced the shells’ weight gain (+56% vs. Control), shell weight (+56%) and crushing force (+135%). Furthermore, an increase in the Met content of the carcass was observed (+18%), along with elevated carcass Ca (+28%) and P (+30%) and higher shell Ca (+12%) and Zn (+87%), alongside reduced carcass Fe (−38%) and Cu (−19%). In Experiment II, the Met-Met group exhibited the highest carcass weight (+16% vs. Control), the greatest carcass-to-body weight ratio, and the highest proportion of mature individuals (+27%). Moreover, Met-Met supplementation improved Cu absorption and retention in the carcass (+19%). Also, the results suggest that the conjugated form of methionine may improve Cu absorption and storage in the carcass (+19%). The study’s findings indicate that methionine addition, especially in Met-Met form, can substantially impact the efficiency of C. aspersum farming, enhancing both the productivity outcomes and the quality of the product. That is particularly important in increasing the shell’s mechanical resistance and the carcass’s nutritional value. Full article

Human amniotic epithelial cell-derived exosomes (hAECs-Exos) are nanoscale extracellular vesicles with neuroprotective, regenerative, and anti-inflammatory properties, presenting a promising cell-free therapeutic approach for ischemic stroke. This study investigated the protective effects of hAECs-Exos against ischemic injury and explored the underlying molecular mechanisms. An optimized oxygen-glucose deprivation/reoxygenation (OGD/R) model was established in murine hippocampal HT22 neurons and BV2 microglial cells to simulate ischemic conditions. hAECs-Exos were successfully isolated and characterized via transmission electron microscopy, nanoparticle tracking analysis, and Western blotting. Confocal microscopy confirmed efficient exosome uptake by both cell types. Functional analyses revealed that hAECs-Exos significantly improved cell viability, suppressed pro-inflammatory cytokine release, alleviated oxidative stress, and modulated apoptosis-related proteins. RNA sequencing identified Forkhead box protein M1 (FoxM1) as a significantly upregulated transcription factor following hAECs-Exos treatment. Further experiments demonstrated that knockdown of FoxM1 in hAECs abolished the beneficial effects of exosomes on the viability of HT22 and BV2 cells and on the suppression of inflammation, oxidative stress, and apoptosis. These findings indicate that hAECs-Exos confer neuroprotection through FoxM1-dependent mechanisms. Together, our results highlight the therapeutic potential of hAECs-Exos as a safe, effective, and clinically translatable strategy for ischemic stroke treatment, warranting future validation in vivo and rescue experiments to fully elucidate FoxM1’s causal role. Full article

Background/Objectives: Modular dual mobility (MDM) cups are constituted by a cobalt-chromium liner inserted into a standard acetabular shell, allowing for intraoperative indication and supplementary screw fixation of the acetabular component. MDM could face mechanical and biological issues, with the associated risk of elevated blood metal ions levels and adverse local tissue reactions. Methods: This is a monocentric retrospective study on a consecutive series of 105 patients who underwent primary unilateral THA with the G7 Dual Mobility Acetabular System cup (Zimmer Biomet, Warsaw, IN, USA) from March 2019 to April 2023, and who were evaluated clinically and radiographically at a minimum two-year follow-up. All complications and revisions were recorded. Survivorship analysis with any revision surgery as endpoint was performed using Kaplan–Meier survival curves. Results: There were eighty-nine patients (follow-up rate 84.8%) who underwent clinical and radiographic follow-up. The mean follow-up was 2.5 ± 0.8 years. Revision-free survival was 98.0%. Three complications (2.8%) were recorded: one case of posterior dislocation, one periprosthetic joint infection and one post-traumatic periprosthetic femur fracture. Dislocation rate and infection rate were less than 1.0%. None of the patients were revised for adverse local tissue reactions. No cup loosening was observed. No cases of intraprosthetic dislocation, liner malseating or femoral notching were observed. Retroacetabular stress shielding was present in 43.0% of patients. Clinical scores significantly improved at the last follow-up compared with preoperative status (p < 0.0001): the final mean mHHS was 87.5 ± 5.3 and the final mean VAS was 0.5 ± 0.9. Conclusions: The Zimmer G7 modular dual mobility cup appears to be a safe and effective option and does not present specific implant-related mechanical and biological issues in primary total hip arthroplasty at a minimum two-year follow-up. Full article

Obesity contributes to the development of metabolic disorders such as type 2 diabetes mellitus (T2DM) and metabolic dysfunction-associated steatotic liver disease (MASLD) through sustained low-grade inflammation and mitochondrial dysfunction. In obesity, hypertrophied adipose tissue release high levels of pro-inflammatory cytokines, including TNF-α, IL-6, and IL-1β, and elevates circulating free fatty acids. These changes promote systemic insulin resistance and ectopic lipid deposition. Mitochondrial dysfunction, including reduced oxidative phosphorylation, excess reactive oxygen species (ROS) production, and mitochondrial DNA damage, further stimulate inflammatory pathways such as the NLRP3 inflammasome, creating a feedback loop that worsens metabolic stress. Ultimately, this interaction disrupts energy balance, weakens insulin signaling, and accelerates β-cell dysfunction and hepatic steatosis. In both T2DM and MASLD, oxidative stress, defective mitochondrial quality control, and dysregulated immunometabolic responses are consistently observed pathophysiological features. Interventions aimed at reducing inflammation and restoring mitochondrial function—including lifestyle modification, mitochondria-targeted therapies, inflammasome regulation, and enhancement of mitochondrial biogenesis or mitophagy—may retard disease progression. Full article

Background: Repeat induced abortion (defined as ≥two lifetime procedures) is becoming more common worldwide, yet its independent influence on women’s psychological health remains contested, particularly in settings where access to modern contraception is restricted. Objectives: This review sought to quantify the burden of depression, anxiety, stress, and generic quality of life (QoL) among women with repeat abortions and to determine how barriers to contraceptive access alter those outcomes. Methods: Following the preregistered PRISMA-2020 protocol, PubMed, Embase and Scopus were searched from inception to 31 June 2025. Results: Eight eligible studies comprising approximately 262,000 participants (individual sample sizes up to 79,609) revealed wide variation in psychological morbidity. Prevalence of clinically significant symptoms ranged from 5.5% to 24.8% for depression, 8.3% to 31.2% for anxiety, and 18.8% to 27% for perceived stress; frequent mental distress affected 12.3% of women in neutral policy environments but rose to 21.9% under highly restrictive abortion legislation. Having three or more abortions, compared with none or one, increased the odds of depressive symptoms by roughly one-third (pooled OR ≈ 1.37, 95% CI 1.13–1.67). Contextual factors exerted comparable or stronger effects: abortions sought for socioeconomic reasons elevated depression odds by 34%, unwanted disclosure of the abortion episode increased depressive scores by 0.62 standard deviations, and low partner support raised them by 0.67 SD. At the structural level, every standard deviation improvement in a state’s reproductive rights index reduced frequent mental distress odds by 5%, whereas enactment of a near-total legal ban produced an absolute increase of 6.8 percentage points. QoL outcomes were less frequently reported; where measured, denied or heavily delayed abortions were associated with a 0.41-unit decrement on a seven-point life satisfaction scale. Conclusions: Psychological morbidity after abortion clusters where legal hostility, financial hardship, or interpersonal coercion constrain contraceptive autonomy while, in comparison, the mere number of procedures is a weaker predictor. Interventions that integrate stigma-free mental health support with confidential, affordable, and rights-based contraception are essential to protect well-being in women who experience repeat abortions. Full article