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Accurate rupture risk assessment is essential for optimizing treatment decisions in patients with cerebral aneurysms. While computational fluid dynamics (CFD) has provided critical insights into aneurysmal hemodynamics, most analyses focus on blood flow patterns, neglecting the biomechanical properties of the aneurysm wall. To address this limitation, we applied Fluid-Structure Interaction (FSI) analysis, an integrative approach that simulates the dynamic interplay between hemodynamics and wall mechanics, offering a more comprehensive risk assessment. In this study, we used advanced FSI techniques to investigate the rupture risk of middle cerebral artery bifurcation (MCA) aneurysms, analyzing a cohort of 125 patients treated for a MCA aneurysm at Kepler University Hospital, Linz, Austria. Multivariate analysis identified two significant rupture predictors: High Equivalent Stress Area (HESA; p = 0.049), which quantifies stress distribution relative to the aneurysm surface, and Gaussian curvature (GLN; p = 0.031), which captures geometric complexity. We also introduce the HGD index, a novel composite metric combining HESA, GLN, and Maximum Wall Displacement, designed to enhance predictive accuracy. With a threshold of 0.075, the HGD index exhibited excellent diagnostic performance; in internal validation, 24 of 25 ruptured aneurysms surpassed this threshold, yielding a sensitivity of 0.96. In a 5-fold cross validation the reliability of results was confirmed. Our findings demonstrate that the HGD index provides superior rupture risk stratification compared to conventional single-parameter models, offering a more robust tool for the assessment of complex aneurysmal structures. Further multicenter studies are warranted to refine and validate the HGD index, advancing its potential for clinical application and improving patient outcomes. [ABSTRACT FROM AUTHOR]

Background: Hemodynamics during the growth process of cerebral aneurysms are incompletely understood. We developed a novel fluid–structure interaction analysis method for the identification of relevant scenarios of aneurysm onset. Method: This method integrates both fluid dynamics and structural mechanics, as well as their mutual interaction, for a comprehensive analysis. Patients with a single unruptured cerebral aneurysm were included. Results: Overall, three scenarios were identified. In scenario A, wall shear stress (WSS) was low, and the oscillatory shear index (OSI) was high in large areas within the region of aneurysm onset (RAO). In scenario B, the quantities indicated a reversed behavior, where WSS was high and OSI was low. In the last scenario C, a behavior in-between was found, with scenarios A and B coexisting simultaneously in the RAO. Structural mechanics demonstrated a similar but independent trend. Further, we analyzed the change in hemodynamics between the onset and a fully developed aneurysm. While scenarios A and C remained unchanged during aneurysm growth, 47% of aneurysms in scenario B changed into scenario A and 20% into scenario C. Conclusions: In conclusion, these findings suggest that WSS and the OSI are reciprocally regulated, and both low and high WSS/OSI conditions can lead to aneurysm onset. [ABSTRACT FROM AUTHOR]

Thermoplastic (TP) composites, known for their ease of handling, suitability for high production rates, and recyclability, are emerging as a promising alternative to thermoset-based composites. The expected growth in TP-based composites in automotive, sports, and aerospace industries may result in increased post industrial waste. To address this, we repurposed our in-house process scrapped carbon fibre-reinforced polycarbonate tapes into sheet moulding compounds (SMCs) and Hybridised SMCs (Hy-SMCs) using compression moulding. In Hy-SMCs, the top and bottom layers were unidirectional tapes, while the core section had randomly oriented platelets in a 50:50 ratio. Our evaluation included qualitative and thermo-mechanical standard tests. The incorporation of unidirectional tapes in Hy-SMCs significantly improved the tensile and flexural properties of SMCs. Specifically, these enhancements resulted in an impressive 81 to 85% increase in mechanical strength compared to the standard aluminium grade. Additionally, Hy-SMCs exhibited a 120 to 130% increase in tensile and flexural properties compared to SMCs. Fractography revealed a complex relation between fractured surfaces, with multimode failures in both SMCs and Hy-SMCs. Also, the non-destructive evaluation showed platelet reorientation during consolidation and localised voids with increased specimen thickness. [ABSTRACT FROM AUTHOR]

Asphalt pavements are fundamental to modern transportation infrastructure, requiring elasticity, firmness, and longevity. However, traditional asphalt, based on bitumen, faces several limitations. To improve pavement performance, polymer resins are being used to substitute bitumen and improve requirements. Therefore, a deep understanding of the material behavior is required. This study presents the analysis of the relaxation behavior of a poly(methyl methacrylate)-based pavement and the influence of mineral fillers. An approach using a linear elastic–viscoelastic material model was selected based on evidence and validated across the linear and nonlinear deformation range. The results reveal no influence of the mineral fillers on the relaxation behavior. The presented modification of the linear elastic and viscoelastic modeling reveals accurate results to predict long-term pavement performance. This approach offers a practical method for forecasting asphalt behavior. Further research is needed to incorporate deformation behavior into the model. [ABSTRACT FROM AUTHOR]

3D inkjet printing is a fast, reliable, and non‐contact bottom–up approach to printing small and large models and is one of the fastest additive manufacturing technologies available. These attributes position inkjet printing as a promising tool for the additive manufacturing of biomaterials, for example, tissue engineering scaffolds. However, due to the stringent technical rheological requirements of current inkjet technologies, there is a lack of photopolymer resins suitable for the inkjet printing of biomaterials. Hence, a novel ink engineered for 3D piezoelectric inkjet printing of biomaterials is designed and developed. The novel resin leverages a biodegradable amino acid phosphorodiamidate matrix copolymerized with a dialkyne ether to modulate the viscosity. Copolymerization with commercially available thiols facilitates the photochemical thiol‐yne curing reaction. The ink exhibits optimal viscosity, eliminating the need for solvents, as well as reliable jetting and sufficiently swift curing kinetics. Furthermore, the formulation is successfully demonstrated in an industrial inkjet printhead. Notably, the resulting materials have low cytotoxicity and, hence, have significant promise in advancing the applications of 3D inkjet printing of biological scaffolds. [ABSTRACT FROM AUTHOR]

Aim: A possible molecular mechanism of clinically defined multidrug-resistant epilepsy involves drug efflux transporters such as P glycoprotein (P-gp), a member of the ATP-binding cassette subfamily B1 (ABCB1). We have investigated the prevalence of the C3435T, G 2677T/A, and T129C single-nucleotide polymorphisms in the promoter region of MDR1 gene, in Romanian epileptic patients.