There have been many attempts to derive continuum models for dense granular flow, but a general theory is still lacking. Here, we start with Mohr-Coulomb plasticity for quasi-two-dimensional granular materials to calculate (average) stresses and slip planes, but we propose a "stochastic flow rule" (SFR) to replace the principle of coaxiality in classical plasticity. The SFR takes into account t...

Symptomatic lumbar degenerative disk disease, or discogenic back pain, is difficult to treat. Patients often report transverse low back pain that radiates into the sacroiliac joints. Radicular or claudicatory symptoms are generally absent unless there is concomitant nerve compression. Physical examination findings are often unremarkable. Radiographic examination may reveal disk space narrowing,...

OBJECTIVES Proper valve selection is critical to ensure appropriate valve replacement for patients, because implantation of a small valve might place the patient at risk for persistent gradients. Labeled valve size is not the same as millimeter measure of prosthetic valve diameters or the annulus into which it will fit. Studies that use the labeled valve size in lieu of actual measured diameter...

BACKGROUND Leaflet curvature is known to reduce mechanical stress. There are 2 major components that contribute to this curvature. Leaflet billowing introduces the most obvious form of leaflet curvature. The saddle shape of the mitral annulus imparts a more subtle form of leaflet curvature. This study explores the relative contributions of leaflet billowing and annular shape on leaflet curvatur...

Trichophyton rubrum is an anthropophilic fungi and has recently become the most common and widely distributed dermatophyte, isolated of man. The infection usually present as superficial scaling annular patches, but the lesions may involved the extensive area of skin.  A case of multiple cutaneous lesions due to T.rubrum with scaling annular patches and well marginated in much of the skin and in...

Acoustic properties of the metamaterial graded absorber, also known as ``acoustic black hole'', are studied in linear regime. The absorber consists thin metallic circular plates, each with a central perforation, separated by annular air cavities. Radius perforation plate is gradually decreasing distance from to front surface, forming channel staircase radius profile. A semi-analytical equivalen...

BACKGROUND AND PURPOSE Annular tears and nuclear degeneration often occur concurrently, but their temporal association remains unknown. The purpose of this study was to assess whether annular tears precede nuclear degeneration and whether the evolution of nuclear degeneration is affected by presence of annular tears. MATERIALS AND METHODS From our radiology report data base, 46 patients with ...

OBJECTIVE Patch closure of the subarterial ventricular septal defect requires suture placement at the pulmonary annulus. We aimed to identify whether patch closure of subarterial ventricular septal defect would affect the growth of pulmonary annulus in comparison with that of perimembranous ventricular septal defect. METHODS Of 361 patients who underwent patch closure of ventricular septal de...

BACKGROUND AND PURPOSE At lumbar diskography, intradiskal lidocaine can eliminate or reduce provoked diskogenic pain. The purpose of this study was to evaluate the postdiskogram CT features of lidocaine-sensitive and lidocaine-insensitive severely painful disks. MATERIALS AND METHODS Intradiskal lidocaine was injected at 182 severely painful levels in 111 patients. Clinical records/imaging st...

Porokeratoses are uncommon hereditary or acquired keratinization disorders due to abnormal clones of keratinocytes in the epidermis. Porokeratoses have several clinical features which may occur simultaneously. A rare type is verrucous porokeratosis (VPK). Herein, we present a 47-year-old man with a 4-year history of perianal verrucous lesions and one year history of annular pruritic lesions on ...