Bioaccumulation of total mercury in the earthworm Eisenia andrei

Earthworms are a major part of the total biomass of soil fauna and play a vital role in soil maintenance. They process large amounts of plant and soil material and can accumulate many pollutants that may be present in the soil. Earthworms have been explored as bioaccumulators for many heavy metal species such as Pb, Cu and Zn but limited information is available for mercury uptake and bioaccumulation in earth- worms and very few report on the factors that influence the kinetics of Hg uptake by earthworms. It is known however that the uptake of Hg is strongly influenced by the presence of organic matter, hence the influence of ligands are a major factor contribut - ing to the kinetics of mercury uptake in biosystems. In this work we have focused on the uptake of mercury by earthworms ( Eisenia andrei ) in the presence of humic acid (HA) under varying physical conditions of pH and temperature, done to assess the role of humic acid in the bioaccumulation of mercury by earthworms from soils. The study was conducted over a 5-day uptake period and all earthworm samples were analysed by direct mercury analysis. Mercury distribution profiles as a function of time, bioac- cumulation factors (BAFs), first order rate constants and body burden constants for mercury uptake under selected conditions of temperature, pH as well as via the dermal and gut route were evaluated in one comprehensive approach. The results showed that the uptake of Hg was influenced by pH, temperature and the presence of HA. Uptake of Hg 2 + was improved at low pH and temperature when the earthworms in soil were in contact with a saturating aqueous phase. The total amount of Hg 2 + uptake decreased from 75 to 48 % as a function of pH. For earthworms in dry soil, the uptake was strongly influenced by the presence of the ligand. Calculated BAF values ranged from 0.1 to 0.8. Mercury uptake typically followed first order kinetics with rate constants determined as 0.2 to 1 h ? 1 .Scopus 201

Bioabsorbable implants for subtalar arthroereisis in pediatric flatfoot

Flatfoot is a common condition in growing-age patients. Despite its common presentation, nowadays surgical indications and treatments are still debated. Arthroereisis is a widely used technique, and several implants designs have been proposed over time. Despite the good results shown in the literature, the main drawback of these techniques has always been the need for a second surgery for implant removal. Bioabsorbable devices have been introduced to overcome this necessity.Correct approach to the patient, indications and contraindications and available studies on bioabsorbable implants for subtalar arthroereisis in pediatric flatfoot were analyzed in this narrative review. Even if only a few studies have been published in the literature, bioabsorbable implants showed good clinical results comparable to non-absorbable implants and with a rare necessity for implant removal or revision. When correct indications and proper surgical technique are followed, arthroereisis with bioabsorbable implants appears to be an effective solution for the treatment of pediatric flexible flatfoot