For unsymmetric block-tridiagonal systems of linear equations arising from the discretization of partial differential equations, a composite preconditioner is proposed and tested. It combines a classical ILU0 factorization for high frequencies with a tangential filtering preconditioner. The choice of the filtering vector is important: the test-vector is the Ritz eigenvector corresponding to the...

Adequate fill of any breast implant, regardless of shell characteristics, shape, or filler material, is important to prevent implant shell wrinkling, folding, or collapse that could potentially decrease the life of the implant. Implant shell life is a major factor that affects reoperation rates. The greater the necessity of reoperations, regardless of implant type, the greater the rate of local...

The patient is a 63-year-old man with stage D heart failure and a left ventricular ejection fraction of <20% who presented to the Houston Methodist Hospital with cardiogenic shock. As a part of his care, he underwent placement of an intra-aortic balloon pump (IABP). The IABP settings were for the balloon to inflate with the aortic dicrotic notch and to deflate near the end of diastole. After as...

background: with respect to physical relations in force and pressure, we hypothesized that the prevalence of traumatic tympanic membrane perforation in patients with a patulous eustachian tube is greater than normal, because in eustachian tube patency, the internal air pressure of the middle ear will not increase after compression, subsequent to trauma. therefore the force upon the tympanic mem...