Bioprosthetic heart valves (BHVs), derived from glutaraldehyde crosslinked (GLUT) porcine aortic valve leaflets or bovine pericardium (BP), are used to replace defective heart valves. However, valve failure can occur within 12–15 years due to calcification and/or progressive structural degeneration. We present a novel fabrication method that utilizes carbodiimide, neomycin trisulfate, and pentagalloyl glucose crosslinking chemistry (TRI) to better stabilize the extracellular matrix of BP. We demonstrate that TRI-treated BP is more compliant than GLUT-treated BP. GLUT-treated BP exhibited permanent geometric deformation and complete alteration of apparent mechanical properties when subjected to induced static strain. TRI BP, on the other hand, did not exhibit such permanent geometric deformations or significant alterations of apparent mechanical properties. TRI BP also exhibited better resistance to enzymatic degradation in vitro and calcification in vivo when implanted subcutaneously in juvenile rats for up to 30 days.

Catastrophic landslides pose significant threats to life and property, and in the case of submarine landslides damage to offshore infrastructure. Although widely discussed, the triggering mechanisms and propagation criteria for catastrophic failure remain open issues. This study investigates a particular case of shear band initiation history: creation of a fully softened initial failure zone in a thin lens of a weaker material causing catastrophic failure of an infinite planar slope in sensitive clay under undrained conditions. The corresponding shear band propagation criteria were derived analytically using a process zone approach and validated numerically using a static large-deformation finite-element method. New analytical solutions taking account of elastic deformations within the shear band and in the entire sliding layer are established for both a linear strength degradation curve and an exponential strength degradation curve. Advantages of formulating propagation criteria in terms of the critical length of the fully softened initial failure zone (excluding process zones) are demonstrated, with the more realistic exponential degradation case producing a more stringent criterion than the linear degradation case.

We explore and quantify all upslope failure possibilities of submarine landslides through 39 numerical modelling and theoretical analyses. 40  We establish a framework for assessing failure initiation, covering different failure mechanisms. 42  We propose simple predictions for scarp position and retrogression limit, which allows rapid 43 assessment of scale of submarine landslides.

Pancreatic ductal adenocarcinoma (PDAC) has a dense extracellular matrix (ECM) surrounding tumor cells to sequester CD8+ T cell infiltration and prevent drug penetration. Concomitant inhibition of both TGF-β pathway and...

The risk posed by seabed instability is of increasing significance as offshore activities including oil and gas developments continue to expand in this century. Many studies have considered runout of debris flows resulting from submarine landslides and potential impact on offshore infrastructure. However, initiation of slab failure resulting from shear band propagation (SBP) at the onset of a landslide has received less attention, although it is of key importance for estimating the scale and consequences of landslides. The present paper explores arrest of SBP as well as global slab failure above the shear band. The complete evolution of a submarine landslide from shear band initiation, propagation, slab failure, and arrest of SBP is observed through large-deformation finite element (LDFE) modelling. Governing equations for both dynamic and quasi-static SBP are established and solved, with results showing good agreement with the LDFE results. Lower limits for the final shear band length and for global slab failure are proposed for cases with high strain-rate dependency of shear strength, where shear band propagation is quasi-static; upper limits are proposed for cases without rate effects where the behaviour is dynamic.

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