We discuss the notion of noncommutative point derivations for operator algebras. We look at the noncommutative point derivations for the quiver algebras, A(Cn) where Cn is the directed graph with n-vertices and n-edges forming a cycle. For the algebras Mn ⊗ A(D) and A(Cn) we classify when non-trivial point derivations can occur. We use the point derivations to show that every derivation on A(Cn...

Background: Attenuation coefficient (μ) plays an important role in calculations of treatment planning systems, as well as determination of dose distributions in external beam therapy, dosimetry, protection, phantom materials and industry. So, its exact measurement or calculation is very important. The aim of this study was to evaluate the μ in different points in the water phantom anal...

The author has published equations for predicting the air borne sound transmission of double leaf cavity walls due to the structure borne sound transmission across the air cavity via (possibly resilient) line connections, but has never published the full derivation of these equations. The author also derived equations for the case when the connections are rigid point connections but has never u...

BACKGROUND AND PURPOSE We aimed to develop a risk score (intracerebral hemorrhage-associated pneumonia score, ICH-APS) for predicting hospital-acquired stroke-associated pneumonia (SAP) after ICH. METHODS The ICH-APS was developed based on the China National Stroke Registry (CNSR), in which eligible patients were randomly divided into derivation (60%) and validation (40%) cohorts. Variables r...

We show that  higher derivations on a Hilbert$C^{*}-$module associated with the Cauchy functional equation satisfying generalized Hyers--Ulam stability.