Self-assembly of Tween 80 micelles as nanocargos for oregano and trans-cinnamaldehyde plant-derived compounds

The self-assembly of Tween 80 (T80) micelles loaded with plant-based oregano essential oil (OR) and trans-cinnamaldehyde (TCA) was studied. The effect of different factors, including the surfactant to oil ratio, the presence of sodium chloride, thermal treatment, and dilution on their formation and physicochemical stability was evaluated. The creation of nano-cargos was confirmed by TEM. The self-associated structures had z-average droplet diameters of 92 to 337 nm without any energy input. Whereas addition of 10% (w/v) NaCl prevented the formation of oregano essential oil nano-assemblies of T80, swollen micelles containing TCA were successfully produced. Moreover, the OR or TCA loaded-micelles had only a slight droplet size variation upon thermal treatment. Ultimately, their antibacterial activity analysis against some food pathogens revealed that the encapsulation of OR and TCA within micelles crucially improved their antibacterial activity. These straightforward and cost-effective designed systems can be applicable in different products, including foods and agrochemicals

Dynamic allocation optimization in A/B tests using classification-based preprocessing

An A/B test evaluates the impact of a new technology by running it in a real production environment and testing its performance on a set of items. Recently, promising new methods are optimizing A/B tests with dynamic allocation. They allow for a quicker result regarding which variation (A or B) is the best, saving money for the user. However, dynamic allocation by traditional methods requires certain assumptions, which are not always verified in reality. This is mainly due to the fact that the populations tested are not homogeneous. This document reports on the new reinforcement learning methodology which has been deployed by the commercial A/B testing platform AB Tasty. We provide a new method that not only builds homogeneous groups for a user, but also allows to find the best variation for these groups in a short period of time. This paper provides numerical results on AB Tasty data, but also on public data sets, to demonstrate an improvement in A/B testing over traditional methods

Fundamental study on the salt tolerance of oregano essential oil-in-water nanoemulsions containing Tween 80

This study provides fundamental information about the influence of salt on the physicochemical stability of oregano essential oil (EO) and its main components incorporated in a nanoemulsion delivery system containing Tween 80 (T80) emulsifier. The emulsion stability was found to be strongly correlated with the lipid phase composition and the type of salts. The oregano essential oil nanoemulsions remained stable for several weeks in the absence of salts. Moreover, they were insensitive to tetrabutylammonium bromide, whereas similar to carvacrol emulsions, they exhibited a rapid phase separation and oiling-off in the presence of sodium chloride. On the other hand, high oleic sunflower oil (HOSO) and p-cymene emulsions remained stable in the presence of NaCl. Addition of 70 and 80% HOSO to the lipid phase of oregano EO and carvacrol, respectively, was found to be sufficient for the formation of emulsions with a high stability to 1.7 M NaCl. Hereby, the morphology of the oregano EO emulsions after 30 days of storage in the presence of NaCl was visualized using a transmission electron microscope. The determination of the surface load and area per surfactant molecule by interfacial tension (IFT) measurements and quartz crystal microbalance with dissipation revealed the dehydration of the polyoxyethylene groups of T80 in the presence of salt. The thickness of the T80 adsorbed layer onto solid hydrophobic and hydrophilic surfaces was significantly lower (p < 0.05) in the presence of sodium chloride. It is hypothesized that a combination of Ostwald ripening and coalescence due to an IFT increase and dehydration was responsible for the instability of the emulsions containing the more polar oregano EO and carvacrol in the presence of salt. The results obtained in this study could be useful for the formulation of essential oil nanoemulsions in the presence of salts applicable in food, pharmaceutical, and personal care products

Soft dentin results in unique flexible teeth in scraping catfishes

Teeth are generally used for actions in which they experience mainly compressive forces acting toward the base. The ordered tooth enamel(oid) and dentin structures contribute to the high compressive strength but also to the minor shear and tensile strengths. Some vertebrates, however, use their teeth for scraping, with teeth experiencing forces directed mostly normal to their long axis. Some scraping suckermouth catfishes (Loricariidae) even appear to have flexible teeth, which have not been found in any other vertebrate taxon. Considering the mineralized nature of tooth tissues, the notion of flexible teeth seems paradoxical. We studied teeth of five species, testing and measuring tooth flexibility, and investigating tooth (micro) structure using transmission electron microscopy, staining, computed tomography scanning, and scanning electron microscopy-energy-dispersive spectrometry. We quantified the extreme bending capacity of single teeth (up to 180 degrees) and show that reorganizations of the tooth (micro) structure and extreme hypomineralization of the dentin are adaptations preventing breaking by allowing flexibility. Tooth shape and internal structure appear to be optimized for bending in one direction, which is expected to occur frequently when feeding (scraping) under natural conditions. Not all loricariid catfishes possess flexible teeth, with the trait potentially having evolved more than once. Flexible teeth surely rank among the most extreme evolutionary novelties in known mineralized biological materials and might yield a better understanding of the processes of dentin formation and (hypo) mineralization in vertebrates, including humans

Antimicrobial peptides in frog poisons constitute a molecular toxin delivery system against predators

Animals using toxic peptides and proteins for predation or defense typically depend on specialized morphological structures, like fangs, spines, or a stinger, for effective intoxication. Here we show that amphibian poisons instead incorporate their own molecular system for toxin delivery to attacking predators. Skin-secreted peptides, generally considered part of the amphibian immune system, permeabilize oral epithelial tissue and enable fast access of cosecreted toxins to the predator's bloodstream and organs. This absorption-enhancing system exists in at least three distantly related frog lineages and is likely to be a widespread adaptation, determining the outcome of predator-prey encounters in hundreds of species

A Hotspot of Amoebae Diversity: 8 New Naked Amoebae Associated with the Planktonic Bloom-forming Cyanobacterium Microcystis

The colonies of Microcystis, one of the most common bloom-forming cyanobacteria worldwide, harbor a diverse community of microorganisms. Among these, naked amoebae feeding on Microcystis cells can strongly influence natural Microcystis population dynamics. In this study, we investigated the species diversity of these amoebae based on 26 Microcystis-associated amoebae (MAA) strains from eutrophied water bodies in Belgium and elsewhere in western Europe. A detailed morphological characterization in combination with 18S rDNA (SSU) phylogenies revealed the presence of no less than 10 species. Nine of these belonged to the known genera Vannella (2 species), Korotnevella (2), Copromyxa (2), Vexillifera (1), Cochliopodium (1) and the recently described Angulamoeba (1). Only two were previously described, the others were new to science. One taxon could not be assigned to a known genus and is here described as Schoutedamoeba gen. n., representing a new variosean lineage. The discovery of so many new species from only one very specific habitat (Microcystis colonies) from a rather restricted geographical area indicates that the diversity of planktonic naked amoebae is much higher than previously appreciated and that only a tiny fraction of the total diversity of naked amoebae is currently known

Electron microscopic characterization of fertilised Dover sole Solea solea eggs during embryonic development

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