Publications

For decades, plasmonic nanoparticles have been extensively studied due to their extraordinary properties, related to localized surface plasmon resonances. A milestone in the field has been the development of the so-called seed-mediated growth method, a synthetic route that provided access to an extraordinary diversity of metal nanoparticles with tailored size, geometry and composition. Such a morphological control came along with an exquisite definition of the optical response of plasmonic nanoparticles, thereby increasing their prospects for implementation in various fields. The susceptibility of surface plasmons to respond to small changes in the surrounding medium or to perturb (enhance/quench) optical processes in nearby molecules, has been exploited for a wide range of applications, from biomedicine to energy harvesting. However, the possibilities offered by plasmonic nanoparticles can be expanded even further by their careful assembly into either disordered or ordered structures, in 2D and 3D. The assembly of plasmonic nanoparticles gives rise to coupling/hybridization effects, which are strongly dependent on interparticle spacing and orientation, generating extremely high electric fields (hot spots), confined at interparticle gaps. Thus, the use of plasmonic nanoparticle assemblies as optical sensors have led to improving the limits of detection for a wide variety of (bio)molecules and ions. Importantly, in the case of highly ordered plasmonic arrays, other novel and unique optical effects can be generated. Indeed, new functional materials have been developed via the assembly of nanoparticles into highly ordered architectures, ranging from thin films (2D) to colloidal crystals or supercrystals (3D). The progress in the design and fabrication of 3D supercrystals could pave the way toward next generation plasmonic sensors, photocatalysts, optomagnetic components, metamaterials, etc. In this Account, we summarize selected recent advancements in the field of highly ordered 3D plasmonic superlattices. We first analyze their fascinating optical properties for various systems with increasing degrees of complexity, from an individual metal nanoparticle through particle clusters with low coordination numbers to disordered self-assembled structures and finally to supercrystals. We then describe recent progress in the fabrication of 3D plasmonic supercrystals, focusing on specific strategies but without delving into the forces governing the self-assembly process. In the last section, we provide an overview of the potential applications of plasmonic supercrystals, with a particular emphasis on those related to surface-enhanced Raman scattering (SERS) sensing, followed by a brief highlight of the main conclusions and remaining challenges.

Abstract Background Genomic relationship matrices are used to obtain genomic inbreeding coefficients. However, there are several methodologies to compute these matrices and there is still an unresolved debate on which one provides the best estimate of inbreeding. In this study, we investigated measures of inbreeding obtained from five genomic matrices, including the Nejati-Javaremi allelic relationship matrix ( F NEJ ), the Li and Horvitz matrix based on excess of homozygosity ( F L&H ), and the VanRaden (methods 1, F VR 1 , and 2, F VR 2 ) and Yang ( F YAN ) genomic relationship matrices. We derived expectations for each inbreeding coefficient, assuming a single locus model, and used these expectations to explain the patterns of the coefficients that were computed from thousands of single nucleotide polymorphism genotypes in a population of Iberian pigs. Results Except for F NEJ , the evaluated measures of inbreeding do not match with the original definitions of inbreeding coefficient of Wright (correlation) or Malécot (probability). When inbreeding coefficients are interpreted as indicators of variability (heterozygosity) that was gained or lost relative to a base population, both F NEJ and F L&H led to sensible results but this was not the case for F VR 1 , F VR 2 and F YAN . When variability has increased relative to the base, F VR 1 , F VR 2 and F YAN can indicate that it decreased. In fact, based on F YAN , variability is not expected to increase. When variability has decreased, F VR 1 and F VR 2 can indicate that it has increased. Finally, these three coefficients can indicate that more variability than that present in the base population can be lost, which is also unreasonable. The patterns for these coefficients observed in the pig population were very different, following the derived expectations. As a consequence, the rate of inbreeding depression estimated based on these inbreeding coefficients differed not only in magnitude but also in sign. Conclusions Genomic inbreeding coefficients obtained from the diagonal elements of genomic matrices can lead to inconsistent results in terms of gain and loss of genetic variability and inbreeding depression estimates, and thus to misleading interpretations. Although these matrices have proven to be very efficient in increasing the accuracy of genomic predictions, they do not always provide a useful measure of inbreeding.

Abstract Ammonia-oxidizing archaea (AOA) of the phylum Thaumarchaeota are widespread in marine and terrestrial habitats, playing a major role in the global nitrogen cycle. However, their evolutionary history remains unexplored, which limits our understanding of their adaptation mechanisms. Here, our comprehensive phylogenomic tree of Thaumarchaeota supports three sequential events: origin of AOA from terrestrial non-AOA ancestors, colonization of the shallow ocean, and expansion to the deep ocean. Careful molecular dating suggests that these events coincided with the Great Oxygenation Event around 2300 million years ago (Mya), and oxygenation of the shallow and deep ocean around 800 and 635–560 Mya, respectively. The first transition was likely enabled by the gain of an aerobic pathway for energy production by ammonia oxidation and biosynthetic pathways for cobalamin and biotin that act as cofactors in aerobic metabolism. The first transition was also accompanied by the loss of dissimilatory nitrate and sulfate reduction, loss of oxygen-sensitive pyruvate oxidoreductase, which reduces pyruvate to acetyl-CoA, and loss of the Wood–Ljungdahl pathway for anaerobic carbon fixation. The second transition involved gain of a K+ transporter and of the biosynthetic pathway for ectoine, which may function as an osmoprotectant. The third transition was accompanied by the loss of the uvr system for repairing ultraviolet light-induced DNA lesions. We conclude that oxygen availability drove the terrestrial origin of AOA and their expansion to the photic and dark oceans, and that the stressors encountered during these events were partially overcome by gene acquisitions from Euryarchaeota and Bacteria, among other sources.

Different techniques and methods have been used to preserve foods. As long as scientific knowledge and technology have improved, new systems were discovered ...

The present study focused on the biological analysis of five plants: Achillea millefolium, Arnica montana, Calendula officinalis, Chamaemelum nobile and Taraxacum officinale. The results indicated that A. montana extracts showed the highest content of phenolic compounds. Regarding the biological properties, A. millefolium had outstanding antioxidant activity, while C. officinalis had the highest rate of antimicrobial and antifungal activity. The anti-inflammatory and cytotoxic activities reflected that C. nobile showed the highest effect. In enzyme assays, C. nobile and C. officinalis extracts showed the highest inhibitory effects on acetylcholinesterase and butyrylcholinesterase enzymes. Overall, this study provides scientific evidence for the evaluation of the potential of medicinal plant extracts for the development of new products.

Abstract Postharvest handling is an important approach to reduce loss and ensure the global supply of fresh fruits and vegetables (FVs). Recently, nanomaterials are increasingly recognized for their great potentials in extending shelf life and maintaining the quality of postharvest FVs owing to their unique properties and outstanding functions with extremely small sizes. This study reviews critically applications of nanotechnology in shelf life extension and quality maintenance of postharvest FVs via nano‐packaging, nano‐coatings, and micro/nano‐bubbles. The advantages of these nanotechnologies to effectively compensate for the shortcomings of the traditional methods are highlighted alongside future research directions at a large low‐cost scale. Generally, nano‐packaging, nano‐coatings, and micro/nano‐bubbles have the functions to modify gas or solvent permeability, inhibit pathogens infection, enhance antimicrobial capacity, and regulate the physiological activity of postharvest FVs. With the development of nanotechnology and quality control measures, it can be expected that green nano‐preservation technology will be an important and novel alternative for the storage and transportation of postharvest FVs.