Search Results (1,493)

The mechanisms underlying reduced deformability of red blood cells (RBCs) in Plasmodium falciparum remain unclear. The decrease in RBC deformability associated with malarial infection was measured using ektacytometry, and only mean values were evaluated. In this study, we report the development of a microfluidic sensing device that can evaluate decreased RBC deformability at the single-cell level by measuring ionic current waveforms through micropores. Using an in vitro culture system, we found that when RBC deformability was reduced by P. falciparum infection, ionic current waveforms changed. As RBC deformability decreased, waveforms became asymmetric. Computer simulations suggested that these waveform parameters are largely independent of RBC size and may represent a reliable indicator of diminished deformability. This novel microfluidic RBC deformability sensor allows for detailed single-cell analysis of malaria-associated deformability reduction, potentially aiding in elucidating its pathology. Full article

Mycosis is caused by, among other factors, filamentous fungi, ubiquitous molds belonging to Aspergillus spp. which are often opportunistic pathogens. Over 100 species of Aspergillus have been described. The most common species responsible for diseases in humans and animals are Aspergillus fumigatus and Aspergillus niger, with Aspergillus flavus and Aspergillus clavatus being somewhat rarer. Aspergillus causes a range of diseases, from localized colonization and hypersensitivity reactions, through chronic necrotizing infections, to rapidly progressing angioinvasion and dissemination, leading to death. Testicular mycosis is extremely rarely described in both humans and animals. No studies in the literature report a simultaneous occurrence of testicular tumors and fungal infection of the organ, so the aim of this paper was to describe, for the first time, a case of two independent testicular tumors coexisting with testicular mycosis. A histopathological examination was performed on the left testicle of a male dog, specifically a mixed-breed dog resembling a husky weighing 22 kg and with an age of 8 years. Bilateral orchidectomy was performed for medical reasons due to the altered outline of the left testicle, leading to scrotal deformation. The dog did not show any clinical signs of illness, and the testicles were not painful. The right testicle, according to the operating veterinarian, showed no macroscopic changes, so histopathological verification was not performed. Microscopic imaging of the changes clearly indicated the coexistence of a tumor process involving Leydig cells (Leydigoma, interstitial cell tumor, ICT), Sertoli cells (Sertolioma), and fungal infection of the testis. The case suggests the possibility of the coexistence of tumor processes, which may have impaired local immune response of the tissue, with an infectious, in this case fungal, inflammatory process. Based on the literature, this paper is the first report on the occurrence of two independent histotype testicular tumors and their associated mycosis. Full article

Wave deformation and sediment transport nearest the shoreside are among the main reasons for sand erosion and beach profile changes. In particular, identifying the areas of incident-wave breaking and longshore current generation parallel to the shoreline is important for understanding the morphological changes of coastal beaches. In this study, a two-phase incompressible flow model along with a sandy sloping topography was employed to investigate the wave deformation and longshore current generation areas in a circular wave basin model. The finite volume method (FVM) was implemented to discretize the governing equations in cylindrical coordinates, the volume-of-fluid method (VOF) was adopted to differentiate the air–water interfaces in the control cells, and the zonal embedded grid technique was employed for grid generation in the cylindrical computational domain. The water surface elevations and velocity profiles were measured in different wave conditions, and the measurements showed that the maximum water levels per wave were high and varied between cases, as well as between cross-sections in a single case. Additionally, the mean water levels were lower in the adjacent positions of the approximated wave-breaking zones. The wave-breaking positions varied between cross-sections in a single case, with the incident-wave height, mean water level, and wave-breaking position measurements indicating the influence of downstream flow variation in each cross-section on the sloping topography. The cross-shore velocity profiles became relatively stable over time, while the longshore velocity profiles predominantly moved in the alongshore direction, with smaller fluctuations, particularly during the same time period and in measurement positions near the wave-breaking zone. The computed velocity profiles also varied between cross-sections, and for the velocity profiles along the cross-shore and longshore directions nearest the wave-breaking areas where the downstream flow had minimal influence, it was presumed that there was longshore-current generation in the sloping topography nearest the shoreside. The computed results were compared with the experimental results and we observed similar characteristics for wave profiles in the same wave period case in both models. In the future, further investigations can be conducted using the presented circular wave basin model to investigate the oblique wave deformation and longshore current generation in different sloping and wave conditions. Full article

Microfluidic methods are an important tool for studying the microrheology of blood and the mechanical properties of blood cells—erythrocytes, leukocytes, and platelets. In patients with diabetes, hypertension, obesity, sickle cell anemia, or cerebrovascular or peripheral vascular diseases, hemorheological alterations are commonly observed. These include increased blood viscosity and red blood cell (RBC) aggregation, along with reduced RBC deformability. Such disturbances significantly contribute to impaired microcirculation and microvascular perfusion. In blood vessels, abnormal hemorheological parameters can elevate resistance to blood flow, exert greater mechanical stress on the endothelial wall, and lead to microvascular complications. Among these parameters, erythrocyte deformability is a potential biomarker for diseases including diabetes, malaria, and cancer. This review highlights recent advances in microfluidic technologies for in vitro assays of RBC deformability and aggregation, as well as leukocyte aggregation and adhesion. It summarizes the core principles of microfluidic platforms and the experimental findings related to hemodynamic parameters. The advantages and limitations of each technique are discussed, and future directions for improving these devices are explored. Additionally, some aspects of the modeling of the microrheological properties of blood cells are considered. Overall, the described microfluidic systems represent promising tools for investigating erythrocyte mechanics and leukocyte behavior. Full article

To address the issues of burr formation, structural deformation, and tearing in the conventional machining of Nomex honeycomb composites, this study aims to clarify the mechanisms by which ultrasonic vibration-assisted cutting enhances machining quality. A multi-scale analysis framework is developed to examine the effects of ultrasonic vibration on fiber distribution, cell-level shear response, and the overall cutting mechanics. At the microscale, analyses show that ultrasonic vibration mitigates stress concentrations, thereby shortening fiber length. At the mesoscale, elastic buckling and plastic yielding models show that ultrasonic vibration lowers shear strength and modifies the deformation. A macro-scale comparison of cutting behavior with and without ultrasonic vibration was conducted. The results indicate that the intermittent contact effect induced by vibration significantly reduces cutting force. Specifically, at an amplitude of 40 μm, the cutting force decreased by approximately 29.7% compared to the condition without ultrasonic vibration, with an average prediction error below 8.6%. Compared to conventional machining, which causes the honeycomb angle to deform to approximately 130°, ultrasonic vibration preserves the original 120° geometry and reduces burr length by 36%. These results demonstrate that ultrasonic vibration effectively reduces damage through multi-scale interactions, offering theoretical guidance for high-precision machining of fiber-reinforced composites. Full article

The mechanical stability and deformability of erythrocytes are vital for their function as they traverse capillaries, where shear stress can reach up to 10 Pa under physiological conditions. Human serum albumin (HSA) is known to help maintain erythrocyte stability by influencing cell shape, membrane integrity, and resistance to hemolysis. However, the precise mechanisms by which albumin exerts these effects remain debated, with some studies indicating a stabilizing role and others suggesting the opposite. This review highlights that under high shear rates, albumin molecules may undergo unfolding due to normal stress differences. Such structural changes can significantly alter albumin’s interactions with the erythrocyte membrane, thereby affecting cell mechanical stability. We discuss two potential scenarios explaining how albumin influences erythrocyte mechanics under shear stress, considering both the viscoelastic properties of blood and those of the erythrocyte membrane. Based on theoretical analyses and experimental evidence from the literature, we propose that albumin’s effect on erythrocyte mechanical stability depends on (i) the transition between unfolded and folded states of the protein and (ii) the impact of shear stress on the erythrocyte membrane’s ζ-potential. Understanding these factors is essential for elucidating the complex relationship between albumin and erythrocyte mechanics in physiological and pathological conditions. Full article

Deep-sea oil and gas pipelines undergo significant plastic strain during reel-lay installation. Additionally, the static strain aging phenomenon that occurs during service can further deteriorate the mechanical properties of the pipelines. This study investigates the plastic deformation mechanism of reel-lay pipeline steel by subjecting the test steel to 5% pre-strain followed by aging treatment at 250 °C for 1 h. The present study systematically correlates the evolution of mechanical properties with microstructural changes through microstructural characterization techniques such as EBSD, TEM, and XRD. The results demonstrate that after pre-straining, the yield strength of the experimental steel increases due to dislocation strengthening and residual stress generation, while its uniform elongation decreases. Although no significant changes in grain size are observed macroscopically, microstructural characterization reveals a substantial increase in dislocation density within the matrix, forming dislocation cells and walls. These substructures lead to a deterioration of the material’s work hardening capacity. Following aging treatment, the tested steel exhibits further increased yield strength and reduced uniform elongation. After aging treatment, although the dislocation density in the matrix slightly decreases and dislocation tangles are somewhat reduced, the Cottrell atmosphere pinning effect leads to a further decline in work hardening capability, ultimately resulting in the deterioration of plasticity in reel-lay pipeline steel. The instantaneous hardening exponent curve shows that the work hardening phenomenon becomes more pronounced in the tested steel after strain aging as the tempering temperature increases. Full article

The use of aluminum honeycomb structures is fast expanding in advanced sectors such as the aeronautics, aerospace, marine, and automotive industries. However, processing these structures represents a major challenge for producing parts that meet the strict standards. To address this issue, an innovative manufacturing method using longitudinal ultrasonic vibration-assisted cutting, combined with a CDZ10 hybrid cutting tool, was developed to optimize the efficiency of traditional machining processes. To this end, a 3D numerical model was developed using the finite element method and Abaqus/Explicit 2017 software to simulate the complex interactions among the cutting tool and the thin walls of the structures. This model was validated by experimental tests, allowing the study of the influence of milling conditions such as feed rate, cutting angle, and vibration amplitude. The numerical results revealed that the hybrid technology significantly reduces the cutting force components, with a decrease ranging from 10% to 42%. In addition, it improves cutting quality by reducing plastic deformation and cell wall tearing, which prevents the formation of chips clumps on the tool edges, thus avoiding early wear of the tool. These outcomes offer new insights into optimizing industrial processes, particularly in fields with stringent precision and performance demands, like the aerospace sector. Full article

Pasteurella multocida (Pm) is a zoonotic pathogen that poses a significant threat to animal health and causes substantial economic losses, further aggravated by rising tetracycline resistance. To restore the efficacy of tetracyclines to Pm, we evaluated the synergistic antibacterial activity of doxycycline combined with metformin, an FDA-approved antidiabetic agent. Among several non-antibiotic adjuvant candidates, metformin exhibited the most potent in vitro synergy with doxycycline, especially against capsular serogroup A strain (PmA). The combination demonstrated minimal cytotoxicity and hemolysis in both mammalian and avian cells and effectively inhibited resistance development under doxycycline pressure. At 50 mg/kg each, the combination of metformin and doxycycline significantly reduced mortality in mice and ducks acutely infected with PmA (from 100% to 60%), decreased pulmonary bacterial burdens, and alleviated tissue inflammation and damage. Mechanistic validation confirmed that metformin enhances membrane permeability in Pm without compromising membrane integrity, dissipates membrane potential, increases intracellular doxycycline accumulation, and downregulates the transcription of the tetracycline efflux gene tet(B). Morphological analyses further revealed pronounced membrane deformation and possible leakage of intracellular contents. These findings highlight metformin as a potent, low-toxicity tetracycline adjuvant with cross-species efficacy, offering a promising therapeutic approach for managing tetracycline-resistant Pm infections. Full article

Sclerotinia sclerotiorum (S. sclerotiorum), a necrotrophic phytopathogen, causes sclerotinia stem rot (SSR) in many crops like oilseed rape, resulting in severe economic losses. Developing eco-friendly compound fungicides has become a critical research priority. This study explored the combination of sodium selenite and cuminic acid to screen for the optimal mixing ratio and investigate its inhibitory effects and mechanisms against S. sclerotiorum. The results demonstrated that synergistic effects were observed with a 1:3 combination ratio of sodium selenite to cuminic acid. After treatment with the selenium compound agent, ultrastructural observations revealed that the hyphae of S. sclerotiorum became severely shriveled, deformed, and twisted. The agent significantly reduced oxalic acid production and the activities of polymethylgalacturonide (PMG) and carboxymethylcellulose enzymes (Cx), while increasing the exocytosis of nucleic acids and proteins from the mycelium. Foliar application of the selenium compound agent significantly reduced lesion areas in rapeseed. Combined with the results of transcriptome sequencing, this study suggests that the compound agent effectively inhibits the growth of S. sclerotiorum by disrupting its membrane system, reducing the activity of cell wall-degrading enzymes, and suppressing protein synthesis, etc. This research provides a foundation for developing environmentally friendly and effective fungicides to control S. sclerotiorum. Full article

Approximately 20% of emissions from air travel are attributed to the auxiliary power units (APUs) carried in commercial aircraft. This paper proposes to reduce greenhouse gas emissions in international air transport by adopting proton-exchange membrane (PEM) fuel cells to replace APUs in commercial aircraft: we consider the design of three compressed hydrogen storage vessels made of 304 stainless steel, 6061-T6 aluminium, and Grade 5 (Ti-6Al-4V) titanium and capable of delivering 440 kW—enough for a PEM fuel cell for a Boeing 777. Complete structural analyses for pressures from 35 MPa to 70 MPa and wall thicknesses of 25, 50, 100, and 150 mm are used to determine the optimal material for aviation applications. Key factors such as deformation, safety factors, and Von Mises equivalent stress are evaluated to ensure structural integrity under a range of operating conditions. In addition, CO₂ emissions from a conventional 440 kW gas turbine APU and an equivalent PEM fuel cell are compared. This study provides insights into optimal material selection for compressed hydrogen storage vessels, emphasising safety, reliability, cost, and weight reduction. Ultimately, this research aims to facilitate the adoption of fuel cell technology in aviation, contributing to greenhouse emissions reduction and hence sustainable air transport. Full article

Deployable thin-film antennas deliver large aperture gains and high stowage efficiency for spaceborne phased arrays but suffer wrinkling-induced planarity loss and radiation distortion. To bridge the lack of electromechanical coupling models for tensioned thin-film patch antennas, we present a unified framework combining structural deformation and electromagnetic simulation. We derive a coupling model capturing the increased bending stiffness of stepped-thickness membranes, formulate a wrinkling analysis algorithm to compute tension-induced displacements, and fit representative unit-cell deformations to a dual-domain displacement model. Parametric studies across stiffness ratios confirm the framework’s ability to predict shifts in pattern, gain, and impedance due to wrinkling. This tool supports the optimized design of wrinkle-resistant thin-film phased arrays for reliable, high-performance space communications. Full article

The increasing adoption of Light Electric Vehicles (LEVs) in urban areas, driven by the micromobility wave, raises significant safety concerns, particularly regarding battery fire incidents. This research investigates the electromechanical performance of aged 18650 lithium-ion batteries (LIBs) from LEVs under mechanical impact conditions. For this study, a battery module from a used e-scooter was disassembled, and its constituent cells were reconfigured into compact modules for testing. To characterize their initial condition, the cells underwent cycling tests to evaluate their state of health (SOH). Although a slight majority of the cells retained an SOH greater than 80%, a notable increase in their internal resistance (IR) was also observed, indicating degradation due to aging. The mechanical impact tests were conducted in adherence to the UL 2271:2018 standard, employing a semi-sinusoidal acceleration pulse. During these tests, linear kinematics were analyzed using videogrammetry, while key electrical and thermal parameters were monitored. Additionally, strain gauges were installed on the central cells to measure stress and deformation. The results from the mechanical shock tests revealed characteristic acceleration and velocity patterns. These findings clarify the electromechanical behavior of aged LIBs under impact, providing critical data to enhance the safety and reliability of these vehicles. Full article

In eukaryotic cells, vesicle-mediated transport interconnects the endomembrane system. These vesicles are formed by coat proteins via deformation of donor membranes. Here, we constructed a set of fluorescent protein-based markers for major coat protein complexes in the yeast model system, and examined their subcellular localization patterns. Our markers covered COPII, COPI, AP-1, AP-2, AP-3, and retromer complexes. Our live cell imaging demonstrates that COPII puncta were primarily associated with the endoplasmic reticulum (ER), and occasionally with early Golgi. COPI was present on both early Golgi and late Golgi/early endosomes. AP-1 puncta were present on late Golgi/early endosomes. AP-2 was present on plasma membrane (PM)-associated puncta, and around the bud neck. AP-3 puncta were present on late Golgi/early endosomes and on the surface of vacuoles. Retromer was present on the surface of vacuoles, late endosomes, and other perivacuolar puncta. Notably, more than half of AP-1 puncta and AP-3 puncta were not associated with the donor compartments where they are thought to be generated, implying that these were coated transport vesicles. This work provides a convenient tool set for the investigation of vesicular transport in yeast and live cell imaging evidence for the presence of certain coated transport vesicles. Full article

Background: Butylated hydroxyanisole (BHA) has been extensively used in several commercial industries as a preservative. It causes severe cellular and neurological damage affecting the developing fetus and might induce attention deficit hyperactivity disorder (ADHD). Methods: Zebrafish embryos were subjected to five distinct doses of BHA—0.5, 1, 2, 4, and 8 ppb up to 96 h post fertilization (hpf). Hatching rate, heart rate, and body malformations were assessed at 48 hpf, 72 hpf, and 48–96 hpf, respectively. After exposure, apoptotic activity, neurobehavioral evaluation, neurotransmitter assay, and antioxidant activity were assessed at 96 hpf. At 120 hpf, the expression of genes DRD4, COMT, 5-HTR1aa, and BDNF was evaluated by real-time PCR. Results: BHA exposure showed a delay in the hatching rate and a decrease in the heart rate of the embryo when compared with the control. Larvae exhibited developmental deformities such as bent spine, yolk sac, and pericardial edema. A higher density of apoptotic cells was observed in BHA-exposed larvae at 96 hpf. There was a decline in catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and superoxide dismutase (SOD) activity, indicating oxidative stress. There was a significant decrease in Acetylcholinesterase (AChE) activity and serotonin levels with an increase in concentration of BHA, leading to a dose-responsive increase in anxiety and impairment in memory. A significant decrease in gene expression was also observed for DRD4, COMT, 5-HTR1aa, and BDNF. Conclusions: Even at lower concentrations of BHA, zebrafish embryos suffered from developmental toxicity, anxiety, and impaired memory due to a decrease in AChE activity and serotonin levels and altered the expression of the mentioned genes. Full article