Multisystem Imaging Manifestations of COVID-19, Part 2: From Cardiac Complications to Pediatric Manifestations.

Infection with severe acute respiratory syndrome coronavirus 2 results in coronavirus disease 2019 (COVID-19), which was declared an official pandemic by the World Health Organization on March 11, 2020. COVID-19 has been reported in most countries, and as of August 15, 2020, there have been over 21 million cases of COVID-19 reported worldwide, with over 800 000 COVID-19-associated deaths. Although COVID-19 predominantly affects the respiratory system, it has become apparent that many other organ systems can also be involved. Imaging plays an essential role in the diagnosis of all manifestations of the disease and its related complications, and proper utilization and interpretation of imaging examinations is crucial. A comprehensive understanding of the diagnostic imaging hallmarks, imaging features, multisystem involvement, and evolution of imaging findings is essential for effective patient management and treatment. In part 1 of this article, the authors described the viral pathogenesis, diagnostic imaging hallmarks, and manifestations of the pulmonary and peripheral and central vascular systems of COVID-19. In part 2 of this article, the authors focus on the key imaging features of the varied pathologic manifestations of COVID-19, involving the cardiac, neurologic, abdominal, dermatologic and ocular, and musculoskeletal systems, as well as the pediatric and pregnancy-related manifestations of the virus. Online supplemental material is available for this article. ©RSNA, 2020

Dose Response of a Novel Exogenous Ketone Supplement on Physiological, Perceptual and Performance Parameters

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Late-Quaternary lowstands of Lake Titicaca: Evidence from high-resolution seismic data

Approximately 600 km of high-resolution seismic reflection data were collected to investigate the late-Quaternary stratigraphic development of Lake Titicaca. The focus of this report is on two seismic sequence boundaries, which are interpreted as erosional surfaces formed at times of low lake level. The younger erosional surface occurs as much as 90 m below the present lake level and up to 8 m below the present sediment–water interface. This erosional surface is interpreted to be coeval with a well-documented early- to mid-Holocene lowstand, dated between ~8,000 and 3,600 cal yr BP. An earlier and previously unknown erosional surface occurs at a sub-bottom depth of approximately 30 m, and as much as 240 m below the present lake level, which implies a major late-Pleistocene lowstand of Lake Titicaca. By extrapolation of sedimentation rates from the upper ~14 m of sediment, we estimate the age of this older lowstand at \u3e90,000 cal yr BP. Both lowstands of Lake Titicaca indicated by the seismic data are likely to have been a response to climatic change in the region

On the role of micro-inertia in enriched continuum mechanics

© 2017 The Author(s) Published by the Royal Society. All rights reserved. In this paper, the role of gradient micro-inertia terms η//∇u,t//2and free micro-inertia terms η//P,t//2is investigated to unveil their respective effects on the dynamic behaviour of band-gap metamaterials. We show that the term η//∇u,t//2alone is only able to disclose relatively simplified dispersive behaviour. On the other hand, the term η//P,t//2alone describes the full complex behaviour of bandgap metamaterials. A suitable mixing of the two micro-inertia terms allows us to describe a new feature of the relaxed-micromorphic model, i.e. the description of a second band-gap occurring for higher frequencies. We also show that a split of the gradient micro-inertia η//∇u,t//2, in the sense of Cartan-Lie decomposition of matrices, allows us to flatten separately the longitudinal and transverse optic branches, thus giving us the possibility of a second band-gap. Finally, we investigate the effect of the gradient inertia η//∇u,t//2on more classical enriched models such as the Mindlin-Eringen and the internal variable ones. We find that the addition of such a gradient micro-inertia allows for the onset of one band-gap in the Mindlin-Eringen model and three band-gaps in the internal variable model. In this last case, however, non-local effects cannot be accounted for, which is a too drastic simplification for most metamaterials. We conclude that, even when adding gradient micro-inertia terms, the relaxed micromorphic model remains the best performing one, among the considered enriched models, for the description of non-local band-gap metamaterials

Segmental testicular infarction due to minocycline-induced antineutrophil cytoplasmic antibody-positive vasculitis

Segmental testicular infarction is an uncommon clinical entity marked by acute scrotal pain and swelling. Classically, these appear as wedge-shaped, avascular, hypoechoic lesions on a testicular ultrasound. We present a unique case of testicular infarct caused by an antineutrophil cytoplasmic antibody-positive vasculitis secondary to the use of the antibiotic minocycline. The patient\u27s symptoms resolved with cessation of minocycline. We suggest that patients who present with otherwise unexplained testicular infarction undergo a careful review of medications to uncover a potential cause. © 2014 Elsevier Inc