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Numerical simulations of fluid-structure interaction (FSI) on an elastic foil heaving with constant amplitude in freestream flow are carried out at a low Reynolds number of 20,000. The commercial software STAR-CCM+ is employed to solve the flow field and the large-scale passive deformation of the structure. The results show that introducing a certain degree of flexibility significantly improves the thrust and efficiency of the foil. For each Strouhal number St considered, an optimal flexibility exists for thrust; however, the propulsive efficiency keeps increasing with the increase in flexibility. The visualisation of the vorticity fields elucidates the improvement of the propulsive characteristics by flexibility. Furthermore, the mechanism of thrust generation is discussed by comparing the time-varying thrust coefficient and vortex structure in the wake for both rigid and elastic foils. Finally, in addition to sinusoidal motions, we also consider the effect of non-sinusoidal trajectories defined by flattening parameter S on the propulsive characteristics for both rigid and elastic foils. The non-sinusoidal trajectories defined by S=2 are associated with the maximum thrust, and the highest values of propulsive efficiency are obtained with S=0.5 among the cases considered in this work.

A bulbous bow is a typical ship structure. Due to the influence of the bulbous bow, complex flow separation and gas capture phenomena may appear during the water entry of ship-like sections. In this paper, experimental and numerical studies on the water entry of a ship-like section with an obvious bulbous bow are carried out. Two thin plates are installed at both ends of the test model to ensure that the flow field during the impact process is approximately two-dimensional. The free-fall drop test is carried out in the test rig equipped with guide rails. By changing drop heights, impact pressure on the model surface with different initial impact velocities is measured. A numerical model for simulating the water entry of the ship-like section is established by using the Computational Fluid Dynamics (CFD) method, based on the Navier-Stokes equations. Reasonable time steps and mesh size are determined by convergence analysis. Four different flow models are used in the numerical analysis. It is found that the K-Epsilon turbulence model can present the most reasonable numerical prediction by comparing numerical results with the experimental data. Furthermore, the influence of the bulbous bow on the impact loads is numerically studied by using the validated numerical model. It suggests that the bulbous bow has little effect on the impact force acting on the bow-flared area but, in the position near the bulbous bow, the pressure will be affected by the second slamming and the air cushion.

Basalt fiber (BF) is deemed a new environmentally friendly and high-performance fiber material due to its high strength, electrical insulation, corrosion resistance and high temperature resistance. Yet, the surface inertness restricts its practical application. In this work, the BF was irradiated and activated by electron beam, followed by in situ growth of SiO2 using a hydrothermal method, then composites with polypropylene (PP) were prepared by microinjection molding. According to the results of scanning electron microscopy (SEM) and Fourier transform infrared (FTIR), more active sites can be formed after irradiation, thus more SiO2 nanoparticles were generated on the surface of BF. Consequently, the rough surface of modified BF could provide stronger shear force during melt processing and resulted in a higher orientation of the molecular chains, increasing the lamellar thickness and generating more highly ordered β crystals in the composites. I400BF-gSiO2 exhibited the highest content of β crystals with the crystallinity of 53.62% and orientation of β (300) crystal plane of 0.91, which were 8.66% and 0.04 higher than those of the composite with pristine BF. Furthermore, due to the perfection of crystals, increased interfaces and interfacial interlocking between PP molecules and modified BF, I400BF-gSiO2 showed good overall performance, with storage modulus of 8000 MPa at −100 °C, glass transition temperature of 23.03 °C and tensile strength of 62.2 MPa, which was 1900 MPa, 1.23 °C and 29.6 MPa higher than neat PP. Hence, the surface roughing strategy proposed in this work is expected to provide some insight and promote the application of BF reinforced thermoplastic composites. [ABSTRACT FROM AUTHOR]

Severe cases of COVID‐19 present hyperinflammatory condition that can be fatal. Little is known about the role of regulatory responses in SARS‐CoV‐2 infection. In this study, we evaluated the phenotype of regulatory T cells in the blood (peripheral blood mononuclear cell) and the lungs (broncho‐alveolar) of adult patients with severe COVID‐19 under invasive mechanical ventilation. Our results show important dynamic variation on Treg cells phenotype during COVID‐19 with changes in number and functional parameters from the day of intubation (Day 1 of intensive care unit admission) to Day 7. We observed that compared with surviving patients, non‐survivors presented lower numbers of Treg cells in the blood. In addition, lung Tregs of non‐survivors also displayed higher PD1 and lower FOXP3 expressions suggesting dysfunctional phenotype. Further signs of Treg dysregulation were observed in non‐survivors such as limited production of IL‐10 in the lungs and higher production of IL‐17A in the blood and in the lungs, which were associated with increased PD1 expression. These findings were also associated with lower pulmonary levels of Treg‐stimulating factors like TNF and IL‐2. Tregs in the blood and lungs are profoundly dysfunctional in non‐surviving COVID‐19 patients. [ABSTRACT FROM AUTHOR]

This study aimed to identify and validate a 9-gene signature for predicting overall survival (OS) in glioma patients. Analysis of multiple gene expression datasets led to the identification of 135 candidate genes associated with OS in glioma patients. Further analysis revealed that IGFBP2, PBK, NRXN3, TGIF1, DNAJA4, and LGALS3BP were identified as risk factors for OS, while ENAH, PPP2R2C, and SPHKAP were found to be protective factors. Multifaceted validation using different databases confirmed their differential expression patterns in glioma tissues compared to normal brain tissue. By utilizing LASSO regression and multivariate Cox regression analysis, a risk score was developed based on the expression levels of the 9 crucial genes. The risk score showed a significant correlation with OS in both training and validation cohorts and yielded superior predictive accuracy compared to individual gene expression. Moreover, a predictive nomogram incorporating the risk score, WHO grade, age, IDH mutation, and 1p/19q co-deletion was constructed and validated, which exhibited high predictive capabilities for survival rates at different time points. Enrichment analysis revealed the involvement of extracellular matrix-related pathways and immune system signaling in glioma prognosis. Furthermore, the risk score showed a strong correlation with immune cell infiltration and immune checkpoint expression, suggesting its potential role in the tumor immune microenvironment. In conclusion, our study provides a robust 9-gene signature and a predictive nomogram for evaluating the prognosis of glioma patients, offering valuable insights into personalized treatment strategies.

Purpose: To investigate the mechanism of action underlying the effective treatment of New Coronavirus Pneumonia Agreement Prescription (NCPAP) on 2019 Novel Coronavirus-Infected Pneumonia (2019-NCIP) using network pharmacology., Methods: In this retrospective study, 50 patients with 2019-NCIP were recruited, including 16 who received symptomatic treatment and 34 that received NCPAP formula treatment on the basis of symptomatic treatment. Hospitalization and lymphocyte percentages were served as efficacy evaluation indicators. Moreover, pharmacological analysis was performed to identify the target disease of NCPAP. Active ingredients in herbs were screened using the Traditional Chinese Medications Systems Pharmacology (TCMSP) database, and related target genes were identified. We then queried therapeutic target data for coronavirus-associated genes. The protein-protein interaction network was constructed to examine the relationships between these targets. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) network enrichment analyses were conducted using the Database for Annotation, Visualization and Integrated Discovery (DAVID) database., Results: NCPAP significantly reduced hospitalization time and increased both the absolute value and percentage of lymphocytes. Bioinformatics and cytokine analysis suggested that preventing cytokine storm syndrome and regulating immune response are the key mechanisms of NCPAP in treating 2019-NCIP., Conclusions: The possible mechanisms of NCPAP in the treatment of 2019-NCIP are reduction of cytokine storms and regulation of the immune response., Competing Interests: None., (AJTR Copyright © 2023.)

Background: Exosomes released from cardiomyocytes (CMs) potentially play an important role in angiogenesis through microRNA (miR) delivery. Studies have reported an important role for miR-29a in regulating angiogenesis and pathological myocardial hypertrophy. However, whether CMderived exosomal miR-29a is involved in regulating cardiac microvascular endothelial cell (CMEC) homeostasis during myocardial hypertrophy has not been determined., Methods: Angiotensin II (Ang II) was used to induce CM hypertrophy, and ultracentrifugation was then used to extract exosomes from a CM-conditioned medium. CMECs were cocultured with a conditioned medium in the presence or absence of exosomes derived from CMs (Nor-exos) or exosomes derived from angiotensin II-induced CMs (Ang II-exos). Moreover, a rescue experiment was performed using CMs or CMECs infected with miR-29a mimics or inhibitors. Tube formation assays, Transwell assays, and 5-ethynyl-20-deoxyuridine (EdU) assays were then performed to determine the changes in CMECs treated with exosomes. The miR-29a expression was measured by qRT-PCR, and Western blotting and flow cytometry assays were performed to evaluate the proliferation of CMECs., Results: The results showed that Ang II-induced exosomal miR-29a inhibited the angiogenic ability, migratory function, and proliferation of CMECs. Subsequently, the downstream target gene of miR- 29a, namely, vascular endothelial growth factor (VEGFA), was detected by qRT-PCR and Western blotting, and the results verified that miR-29a targeted the inhibition of the VEGFA expression to subsequently inhibit the angiogenic ability of CMECs., Conclusion: Our results suggest that exosomes derived from Ang II-induced CMs are involved in regulating CMCE proliferation, migration, and angiogenesis by targeting VEGFA through the transfer of miR-29a to CMECs., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)