Search

The Museo Nazionale della Scienza e della Tecnologia "Leonardo da Vinci" in Milan is exposing two pairs of canal lock gates, used to control the water flow in Milan canal system, whose design appears in the Leonardo's Codex Atlanticus. The wood present in the gates has been deeply characterised by mean of a multidisciplinary investigation involving i) DNA barcoding of wood fragments; ii) microbial community characterisation, and iii) chemical analyses. DNA barcoding revealed that two fragments of the gates belonged to wood species widely used in the middle age: Fagus sylvatica and Picea abies. The chemical characterisations were based on the use of ionic liquid as dissolving medium in order to analyse the entire cell wall material by means of Gel Permeation Chromatography (GPC) and 2D-NMR-HSQC techniques. This multidisciplinary analytical approach was able to highlight the complex nature of the degradation occurred during the gate operation (XVI-XVIII centuries): an intricate interplay between microbial populations (i.e. Shewanella), inorganic factors (i.e. iron from nails), physical factors and the lignocellulosic material., Competing Interests: The authors have declared that no competing interests exist.

This study was undertaken to investigate combined toxic and genotoxic effects of cadmium (Cd) and arsenic (As) on white clover, a pollutant sensitive plant frequently used as environmental bioindicator. Plants were exposed to soil spiked with increasing concentrations of cadmium sulfate (20, 40 and 60 mg Kg-1) or sodium arsenite (5, 10 and 20 mg Kg-1) as well as with their combinations. Metal(loid) bioavailability was assessed after soil contamination, whereas plant growth, metal(loid) concentration in plant organs and DNA damage were measured at the end of plant exposition. Results showed that individual and joint toxicity and genotoxicity were related to the concentration of Cd and As measured in plant organs, and that As concentration was the most relevant variable. Joint effects on plant growth were additive or synergistic, whereas joint genotoxic effects were additive or antagonistic. The interaction between Cd and As occurred at both soil and plant level. In soil the presence of As limited the bioavailability of Cd, whereas the presence of Cd increased the bioavailability of As. Nevertheless only As biovailability determined the amount of As absorbed by plants. The amount of Cd absorbed by plant was not linearly correlated with the fraction of bioavailable Cd in soil suggesting the involvement of additional factors, such as plant uptake mechanisms. These results reveal that the simultaneous presence in soil of Cd and As, although producing an additive or synergistic toxic effect on Trifolium repens L. growth, generates a lower DNA damage.