Correction: Influence of 4f filling on electronic and magnetic properties of rare earth-Au surface compounds

Correction for ‘Influence of 4f filling on electronic and magnetic properties of rare earth-Au surface compounds’ by L. Fernandez et al., Nanoscale, 2020, 12, 22258–22267, DOI: 10.1039/D0NR04964F.

Influence of 4f filling on electronic and magnetic properties of rare earth-Au surface compounds

HoAu2, YbAu2 and GdAu2 surface compounds are investigated by electron spectroscopies, microscopy and theory. Yb in YbAu2 reveals a mixed valence character while Gd and Ho are trivalent. HoAu2 is ferromagnetic with an out-of-plane easy axis and TC = 22 K.

Investigation of interaction of Co, Mn and Fe atoms with the calcite by X-ray photoelectron spectroscopy

Adsorption of atoms of Co, Mn, Fe on the calcite surface in ultra-high vacuum and the interaction of the formed adsorption systems with the water have been studied by means of X-ray photoelectron spectroscopy. It is shown that Mn and Fe form solid solutions CaCO3/Mn(Fe)CO3 on the calcite surface, whereas Co preferentially forms CoO and Co3O4. Upon interaction with water the surface compounds formed by Mn and Fe do not undergo notable changes, unlike the Co oxides which partially transform into soluble hydroxylated complexes.

Relationship Between Hydrocarbon Composition on the Cuticle of Melipona quadrifasciata (Hymenoptera: Apidae) Workers and the Secretion of the Cephalic Salivary Glands

Since chemical communication is pivotal for social insect success, the present paper aimed to quantify and qualify the chemical compounds that might have pheromonal role in both cephalic salivary gland and epicuticle of workers of Melipona quadrifasciata Lepeletier using gas chromatographymass spectrometry (GC/MS). The results indicated that the hydrocarbons were the main compounds in both cephalic salivary gland and epicuticle, followed by esters. Positive Mantel correspondence analysis suggests that the glands could contribute to replenishment of surface compounds as an auxiliary source. Discriminant analysis also pointed out that gland and epicuticle chemical profi les were phase-related.

Environmental Metabolomics of the Tomato Plant Surface Provides Insights on Salmonella enterica Colonization

ABSTRACTFoodborne illness-causing enteric bacteria are able to colonize plant surfaces without causing infection. We lack an understanding of how epiphytic persistence of enteric bacteria occurs on plants, possibly as an adaptive transit strategy to maximize chances of reentering herbivorous hosts. We used tomato (Solanum lycopersicum) cultivars that have exhibited differential susceptibilities toSalmonella entericacolonization to investigate the influence of plant surface compounds and exudates on enteric bacterial populations. Tomato fruit, shoot, and root exudates collected at different developmental stages supported growth ofS. entericato various degrees in a cultivar- and plant organ-dependent manner.S. entericagrowth in fruit exudates of various cultivars correlated with epiphytic growth data (R2= 0.504;P= 0.006), providing evidence that plant surface compounds drive bacterial colonization success. Chemical profiling of tomato surface compounds with gas chromatography-time of flight mass spectrometry (GC-TOF-MS) provided valuable information about the metabolic environment on fruit, shoot, and root surfaces. Hierarchical cluster analysis of the data revealed quantitative differences in phytocompounds among cultivars and changes over a developmental course and by plant organ (P< 0.002). Sugars, sugar alcohols, and organic acids were associated with increasedS. entericagrowth, while fatty acids, including palmitic and oleic acids, were negatively correlated. We demonstrate that the plant surface metabolite landscape has a significant impact onS. entericagrowth and colonization efficiency. This environmental metabolomics approach provides an avenue to understand interactions between human pathogens and plants that could lead to strategies to identify or breed crop cultivars for microbiologically safer produce.IMPORTANCEIn recent years, fresh produce has emerged as a leading food vehicle for enteric pathogens.Salmonella-contaminated tomatoes represent a recurrent human pathogen-plant commodity pair. We demonstrate thatSalmonellacan utilize tomato surface compounds and exudates for growth. Surface metabolite profiling revealed that the types and amounts of compounds released to the plant surface differ by cultivar, plant developmental stage, and plant organ. Differences in exudate profiles explain some of the variability inSalmonellacolonization susceptibility seen among tomato cultivars. Certain medium- and long-chain fatty acids were associated with restrictedSalmonellagrowth, while sugars, sugar alcohols, and organic acids correlated with largerSalmonellapopulations. These findings uncover the possibility of selecting crop varieties based on characteristics that impair foodborne pathogen growth for enhanced safety of fresh produce.