Hyaluronic acid (HA) is a major component of cartilage extracellular matrix and is an attractive material for use as 3D injectable matrices for cartilage regeneration. While previous studies have shown the promise of HA-based hydrogels to support cell-based cartilage formation, varying HA concentration generally led to simultaneous changes in both biochemical cues and stiffness. How cells respo...

Combining several materials (“phases”) into a composite material permits creation of new materials with tunable overall response, e.g., elastic properties, which can be related to the elastic moduli, arrangement, and concentrations of the composite’s phases. A recent advance predicts use of one phase having correctly tuned non-positive-definite elastic moduli (i.e., negative stiffness) in a two...

it is well-known that dam-reservoir interaction has significant effects on the response of dams to the earthquakes. this phenomenon should be considered more exactly in the seismic design of dams with a rational and reliable dynamic analysis method. in this research, seismic analysis of the dam-reservoir is studied as a wave propagation problem by using legendre spectral element method (sem). t...

Cells in the body exist in a dynamic mechanical environment where they are subject to mechanical stretch as well as changes in composition and stiffness of the underlying extracellular matrix (ECM). However, the underlying mechanisms by which cells sense and adapt to their dynamic mechanical environment, in particular to stretch, are not well understood. In this study, we hypothesized that emer...

Stem cell differentiation can be highly sensitive to mechanical inputs from the extracellular matrix (ECM). Identifying temporal windows during which lineage commitment responds to ECM stiffness, and the signals that mediate these decisions, would advance both mechanistic insights and translational efforts. To address these questions, we investigate adult neural stem cell (NSC) fate commitment ...

Starting from the solutions of governing differential equations motion in free vibration, frequency dependent mass and stiffness matrices bar beam elements have been derived this paper, but importantly, their equivalency with corresponding dynamic matrix is established. In sharp contrast to series solutions, reported literature, explicit expressions for each term are generated concise form thro...

A generalised method for the identification of the parameters which describe the dynamic properties of media between coupled substructures using measured FRFs is presented in this paper. The effort is mainly focused on the development of this generalised method and the improvement of its constituent algorithms. The method presented here is more general and more practical in some aspects when co...

Using numerical integration in the formulation of the finite-element geometric stiffness matrix and placing movable nodes at integration points causes the geometric stiffness matrix to become lumped or diagonal. The consistent geometric stiffness matrix which is a non-diagonal matrix, is normally used in the finite-element eigenvalue buckling problem. Altering the method to deliver a diagonal (...