https://www.selleckchem.com/products/ulonivirine.html Background Potentially toxic elements, such as lead, can bioaccumulate and alter human physiology. Human biomonitoring is an essential tool to evaluate chemical exposures in different biological matrices (blood, urine, saliva, nails, and hair). Of these biological matrices, nails are favorable for their ease of sampling, transport and storage. The aim of this study was to investigate possible correlations between blood lead levels (BLL) and washed and non-washed fingernail lead levels (FLL) in 55 adults living in a lead-contaminated area. Method Venous blood and fingernail (thumbs and forefingers) samples were collected. Nails from the left hand were washed with Triton X-100 (0.5 % m/v) and HNO3 solution, while nails from the right hand were not submitted to the pre-analytical procedures. Samples were analyzed by graphite furnace atomic absorption spectrometry, and pairwise correlations were used to correlate lead concentrations between BLL and FLL; nails from fingers of the same hand and between washed and u concentrations between fingers is poor for fingernail lead levels to serve as an internal dose biomarker to lead exposure. In addition, levels in washed nails were not significantly correlated with blood lead levels. Fingernail lead levels seem to serve as an indicator of lead exposure sources in contact with the individual, but not as a reliable biomarker of internal dose.Background Boron is a trace element that plays an important role in numerous biological functions, including calcium metabolism, growth and maintenance of bone tissue. However, there are still no precise indications regarding a possible role of boron supplementation, and its amount of supplementation, to maintain bone health. So the aim of this narrative review was to consider the state of the art on the effectiveness of boron supplementation (alone or with other micronutrients) on growth and maintenance of bone in humans through control o