Squalamine: An Appropriate Strategy against the Emergence of Multidrug Resistant Gram-Negative Bacteria?

We reported that squalamine is a membrane-active molecule that targets the membrane integrity as demonstrated by the ATP release and dye entry. In this context, its activity may depend on the membrane lipid composition. This molecule shows a preserved activity against bacterial pathogens presenting a noticeable multi-resistance phenotype against antibiotics such as polymyxin B. In this context and because of its structure, action and its relative insensitivity to efflux resistance mechanisms, we have demonstrated that squalamine appears as an alternate way to combat MDR pathogens and by pass the gap regarding the failure of new active antibacterial molecules

Element-specific magnetometry of EuS nanocrystals

A soft x-ray absorption and x-ray magnetic circular dichroism (XMCD) study of the ferromagnetism in solution-grown EuS nanocrystals (NCs) is reported. The absorption edges of Eu M5 and M4, S K, O K, and P K were probed to determine elementally specific contributions to the magnetism of EuS NCs. Differential spin absorption was observed by XMCD at the Eu M5,4 edges confirming the presence of a magnetic moment on the Eu2+ 4f shell. No dichroic signal was observed for S, O, or P. Vibrating sample magnetometry of ensembles of NCs shows ferromagnetic properties consistent with the XMCD studies

Quantitative imaging of carbon dimer precursor for nanomaterial synthesis in the carbon arc

Delineating the dominant processes responsible for nanomaterial synthesis in a plasma environment requires measurements of the precursor species contributing to the growth of nanostructures. We performed comprehensive measurements of spatial and temporal profiles of carbon dimers in sub-atmospheric-pressure carbon arc by laser-induced fluorescence. Measured spatial profiles of carbon dimers coincide with the growth region of carbon nanotubes (Fang et al 2016 Carbon 107 273-80) and vary depending on the arc operation mode, which is determined by the discharge current and the ablation rate of the graphite anode. The carbon dimer density profile exhibits large spatial and time variations due to motion of the arc core. A comparison of the experimental data with the 2D simulation results of self-consistent arc modeling shows a good agreement. The model predicts well the main processes determining spatial profiles of carbon dimers.Read me and data files