Symmetric 3-periodic polycatenanes: catenated rings, polyhedra and rods.

We report symmetric (vertex- and arc-transitive) embeddings of catenated rings, polyhedra and rods. Linked triangles form infinite families of structures, and we limit this report to only structures with each ring linked to three or six others. For linked squares, hexagons, tetrahedra, octahedra, cubes and rods, only a small number of symmetric structures were found, and all are reported.

Periodic graphs with coincident edges: folding-ladder and related graphs.

Ladder graphs admit a maximum-symmetry embedding in which edges coincide. In folding ladders, there are no zero-length edges. We give examples of high-symmetry 3-periodic ladders, particularly emphasizing the structures of 3-periodic vertex- and edge-transitive folding ladders.

Periodic diffraction from an aperiodic monohedral tiling - the Spectre tiling. Addendum.

This article describes the diffraction pattern (2-periodic Fourier transform) from the vertices of a large patch of the recently discovered `Spectre' tiling - a strictly chiral aperiodic monotile. It was reported recently that the diffraction pattern of the related weakly chiral aperiodic `Hat' monotile was 2-periodic with chiral plane-group symmetry p6 [Kaplan et al. (2024).

Vitreoretinal large B- cell lymphoma (VR- LBCL): Clinical and pathological features and treatment outcomes.

Context: Vitreoretinal large B- cell lymphoma (VR- LBCL) is a type of non- Hodgkin lymphoma confined to the eye and central nervous system (CNS). The clinical manifestations of intraocular lymphoma can precede, occur simultaneously with, or follow disease at CNS sites. It differs from other forms of extra-nodal lymphoma; in that it does not involve systemic sites other than CNS.

Emergency Presentations of Coronavirus Disease (COVID-19): A Review of the Literature and Radiologic Perspective.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the debilitating global pandemic known as Coronavirus disease (COVID-19). In this paper, we highlight the widespread manifestations and complications across disease systems. In addition, we present their relevant imaging findings to inform appropriate investigations and management in patients presenting to the Emergency Department with COVID-19 and its respective sequalae.