Search

In this work, we implemented an off-axis digital holographic microscopy (DHM) setup to study the behavior of liquid drops on nanostructured porous silicon (PS) membranes. When a liquid comes into contact with the PS structure, capillary action and surface tension give rise to imbibition of the liquid into the intricate volume of the pores. At the same time, the vapor field developed around the drop enhances liquid condensation and evaporation into and from the pores. The complex interplay between these phenomena (capillary driven internal flows, condensation, and evaporation) is not yet fully understood but the methods we propose can provide new insights. We demonstrate how DHM allows determining the filling fraction of the porous membrane around drying drops of water and isobutyl alcohol. The phase information obtained from registered holograms provides quantitative information that permits to reconstruct the filling fraction along the porous membrane and its evolution during the drying process. Additionally, relevant parameters such as speed and contact angle during retraction of the drops can be measured. These methods can be further extended to other porous materials, such as porous alumina, micro- and macro-PS, to develop better fluid-dynamic models for describing fluid behavior in highly confined structures. [ABSTRACT FROM AUTHOR]

Patients with severe COVID-19 can develop painful range-of-motion restrictions of large joints due to heterotopic ossification. We present the case of a patient who developed hip pain after prolonged admission for severe COVID-19 pneumonia. Conventional radiography, computed tomography and bone scan showed extensive heterotopic ossification in the hips. It is probable that both local and systemic factors contribute to the development of heterotopic ossifications and it is necessary to rule out this entity when these patients reported joint pain. Early diagnosis is important to provide non-pharmacological interventions such as mild passive mobilization and anti-inflammatory medication and in refractory cases surgical resection of the ectopic bone is consider., (Copyright © 2021 Sociedad Española de Rehabilitación y Medicina Física. Publicado por Elsevier España, S.L.U. All rights reserved.)