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We have used X-ray magnetic circular dichroism to determine the orbital and spin moments in exposed and embedded mass-selected Fe nanoclusters (250-550 atoms) deposited in situ using a gas aggregation source. The isolated and exposed particles have a total moment that increases with decreasing cluster size and reaches 2.4 [[mu].sub.B] in 250-atom clusters. Although this is enhanced relative to the bulk, it is smaller than found in free clusters of the same size. Coating the exposed clusters with Co, however, increases the spin moment to 2.6 [[mu].sub.B]. The prospects for producing high-moment materials by cluster assembly are discussed. Index Terms--Clusters, nanomagnetism.

The pathogen Staphylococcus aureus can readily develop antibiotic resistance and evade the human immune system, which is associated with reduced levels of neutrophil recruitment. Here, we present a class of antibacterial peptides with potential to act both as antibiotics and as neutrophil chemoattractants. The compounds, which we term 'antibiotic-chemoattractants', consist of a formylated peptide (known to act as chemoattractant for neutrophil recruitment) that is covalently linked to the antibiotic vancomycin (known to bind to the bacterial cell wall). We use a combination of in vitro assays, cellular assays, infection-on-a-chip and in vivo mouse models to show that the compounds improve the recruitment, engulfment and killing of S. aureus by neutrophils. Furthermore, optimizing the formyl peptide sequence can enhance neutrophil activity through differential activation of formyl peptide receptors. Thus, we propose antibiotic-chemoattractants as an alternate approach for antibiotic development., (© 2021. The Author(s).)