Medicine by Alexandros G. Sfakianakis

The contribution of a directional preference of stiffness to the efficacy of prophylactic sacral dressings in protecting healthy and diabetic tissues from pressure injury: computational modelling studies Abstract The sacral region is the most common site for pressure injuries (PIs) associated with lying in bed, and such sacral PIs often commence as deep tissue injuries (DTIs) that later present as open wounds. In complex patients, diabetes is common. Because, among other factors, diabetes affects connective tissue stiffness properties, making these tissues less able to dissipate mechanical loads through physiological deformations, diabetes is an additional biomechanical risk factor for PIs and DTIs. A preventive measure with established successful clinical outcomes is the use of sacral prophylactic dressings. The objective of this study has been to expand our previous work regarding the modes of action and biomechanical efficacy of prophylactic dressings in protecting the soft tissues adjacent to the sacrum by specifically examining the role of a directional stiffness preference (anisotropy) of the dressing while further accounting for diabetic tissue conditions. Multiple three-dimensional anatomically detailed finite element (FE) model variants representing diabetic tissue conditions were used, and tissue loading state data were compared with healthy tissue simulations. We specifically compared soft tissue exposures to elevated internal shear stresses and strain energy densities (SED) near the sacrum during supine weight bearing on a standard (foam) hospital mattress without a dressing, with a prophylactic dressing lacking directional stiffness preferences and with an anisotropic dressing. Our results have clearly shown that an anisotropic dressing design reduces the peak tissue stresses and exposure to sustained tissue deformations in both healthy and diabetic cases. The present study provides additional important insights regarding the optimal structural and material design of prophylactic dressings, which in turn, informs clinicians and decision makers regarding beneficial features.

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Occupational Exposure to Inhalable Manganese at German Workplaces Abstract Due to mounting evidence of neurotoxic effects of manganese (Mn) already at low concentrations, occupational exposure limits (OELs) have been adopted. We analyzed 5771 personal measurements of inhalable manganese (Mn) together with information on sampling conditions and job tasks from the German exposure database Messdaten zur Exposition gegenüber Gefahrstoffen am Arbeitsplatz (MEGA) to assess exposure levels in welders and other occupations between 1989 and 2015. Geometric means (GMs) of exposure to Mn were estimated for various occupational settings adjusted for 2-h sampling duration and analytical method, centered at 2009. Measurements below the limit of quantification (LOQ) were multiply imputed. The median concentration was 74 µg m−3 (inter-quartile range 14–260 µg m−3) in welders and 8 µg m−3 (inter-quartile range <LOQ–31 µg m−3) in other occupations. Every third measurement was higher than 100 µg m−3, 20% exceeded 200 µg m−3, and 5% of welders inhaled concentrations ≥1000 µg m−3. GMs >100 µg m−3 were observed in gas metal and flux-cored arc welders and in shielded metal arc welders using consumables of high Mn content (>5%). Tungsten inert gas welding, laser welding and working in other occupations such as foundry worker, electroplater, or grinder were associated with GMs <10 µg m−3. A shorter sampling duration was associated with higher Mn concentrations. High-emission welding techniques require protective measures to cope with adopted OELs. Results of this study are useful to assess cumulative Mn exposure in community-based studies on neurotoxic effects.

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The role of the ugly duckling sign in patient education The ABCDE (with A standing for asymmetry, B for border irregularity, C for color variegation, D for diameter larger than 6 mm, and E for evolution) rule for melanoma (MM) recognition is widely taught in the general population. The ugly duckling (UD) sign is an alternate MM recognition strategy that is not generally taught.