OBJECTIVE The purpose of this article is to provide an overview of ultrasound and MR elastography, including a glossary of relevant terminology, a classification of elastography techniques, and a discussion of their respective strengths and limitations. CONCLUSION Elastography is an emerging technique for the noninvasive assessment of mechanical tissue properties. These techniques report metr...

These complex systems often consist of mechanically graded structures that resist and respond to external normal and shear forces, and therefore protect underlying tissues from incurring any damage. As an example, the human epidermis consists of keratinizing epithelial cells—an elastic layer with low modulus—buried under a layer of dead cells, the stratum corneum , with higher modulus. The stra...

An easy to implement modulus-squared Dirichlet (MSD) boundary condition is formulated for numerical simulations of time-dependent complex partial differential equations in multidimensional settings. The MSD boundary condition approximates a constant modulus-square value of the solution at the boundaries. Application of the MSD boundary condition to the nonlinear Schrödinger equation is shown, a...

OBJECTIVE To assess in a high-resolution model of thin liver rat slices which viscoelastic parameter at three-dimensional multifrequency MR elastography has the best diagnostic performance for quantifying liver fibrosis. MATERIALS AND METHODS The study was approved by the ethics committee for animal care of our institution. Eight normal rats and 42 rats with carbon tetrachloride induced liver...

We study the evolution of the elastic shear modulus of weakly aggregated colloidal particles during the onset of a delayed collapse under gravity. The early lifetime is characterised by an elastic shear modulus that increases logarithmically in time, following which the gels experience a catastrophic failure and the elastic modulus drops dramatically. As the gel collapses, various complex behav...

The control of the optical quality of a laser beam requires a complex amplitude measurement able to deal with strong modulus variations and potentially highly perturbed wavefronts. The method proposed here consists in an extension of phase diversity to complex amplitude measurements that is effective for highly perturbed beams. Named camelot for Complex Amplitude MEasurement by a Likelihood Opt...

Zero/constant modulus (ZCM) signals are complex signals for which every sample is either zero or has modulus 1. Such signals arise after imprecise carrier-to-baseband conversion of binary {0;1}-modulated signals, or with intermittent phase-modulated signals. We consider the separation of linear superpositions of such signals using analytic techniques. An application is the separation of multipl...

We study a SU(2) gauge theory with a classical complex modulus. Introducing a chemical potential for a conserved modulus hypercharge causes it to become unstable and start condensing. We show that the modulus condensation in turn generates homogeneous but anisotropic non-abelian field strength condensates. The existence of a stable vacuum at the end point of the condensation process depends on ...

OBJECTIVE Handling of endodontic sealers is greatly dependent on their elasticity and flow ability. We compared the viscoelastic properties of three root canal sealers. MATERIALS AND METHODS AH Plus (Dentsply, De Trey, Konstanz, Germany), Endofill (Dentsply Hero, Petrópolis, Rio de Janeiro, Brazil) and AH26 (Dentsply, De Trey, Konstanz, Germany) were mixed according to the manufacturers' inst...

The collagenous dura mater isolates the brain from the external environment and requires a secure closure following invasive neurosurgery. This is typically accomplished by approximation of the dura mater via sutures and adhesives. In selected cases, however, large portions of dura mater require excision, necessitating a tissue replacement patch. The mild reaction conditions and long-term bioco...