Artificial Intelligence for reverse engineering: application to detergents using Raman spectroscopy

The reverse engineering of a complex mixture, regardless of its nature, has become significant today. Being able to quickly assess the potential toxicity of new commercial products in relation to the environment presents a genuine analytical challenge. The development of digital tools (databases, chemometrics, machine learning, etc.) and analytical techniques (Raman spectroscopy, NIR spectroscopy, mass spectrometry, etc.) will allow for the identification of potential toxic molecules. In this article, we use the example of detergent products, whose composition can prove dangerous to humans or the environment, necessitating precise identification and quantification for quality control and regulation purposes. The combination of various digital tools (spectral database, mixture database, experimental design, Chemometrics / Machine Learning algorithm{\ldots}) together with different sample preparation methods (raw sample, or several concentrated / diluted samples) Raman spectroscopy, has enabled the identification of the mixture's constituents and an estimation of its composition. Implementing such strategies across different analytical tools can result in time savings for pollutant identification and contamination assessment in various matrices. This strategy is also applicable in the industrial sector for product or raw material control, as well as for quality control purposes

Prenucleation self-assembly and chiral discrimination mechanisms during solution crystallisation of racemic diprophylline

The crystallisation behaviour of (RS)-diprophylline (DPL) in two different solvents is investigated to assess the incidence of solvated pre-associations on nucleation, crystal growth and chiral discrimination. In the solvated state, Raman spectroscopy shows that dimeric associations similar to those depicted in the crystalline solid solution (ssRII) predominate in isopropanol (IPA), which may account for the systematic spontaneous nucleation of this crystal form from this solvent. By contrast, spontaneous nucleation in DMF yields the stable racemic compound RI, consistently with the distinct features of the Raman spectrum collected in this solvent. A crystal growth study of ssRII in IPA reveals that the crystal habitus is impacted by the solution enantiomeric excess; this is explained by increased competition between homo- and heterochiral pre-associations. This is supported by a molecular modelling study on the enantiomeric selectivity of the DPL crystal lattices. The combination of assessment methods on solution chemistry, nucleation and chiral discrimination provides methodological tools from which the occurrence of solid solutions can be rationalised

Array of Individual Circular Rydberg Atoms Trapped in Optical Tweezers

Circular Rydberg atoms (CRAs), i.e., Rydberg atoms with maximal orbital momentum, are highly promising for quantum computation, simulation and sensing. They combine long natural lifetimes with strong inter-atomic interactions and coupling to electromagnetic fields. Trapping individual CRAs is essential to harness these unique features. We report the first demonstration of CRAs laser-trapping in a programmable array of optical bottle beams. We observe the decay of a trapped Rubidium circular level over 5ms using a novel optical detection method. This first optical detection of alkali CRAs is both spatially- and level selective. We finally observe the mechanical oscillations of the CRAs in the traps. This work opens the route to the use of circular levels in quantum devices. It is also promising for quantum simulation and information processing using the full extent of Rydberg manifolds

Antibacterial Properties of Polyphenols: Characterization and QSAR (Quantitative Structure–Activity Relationship) Models

Besides their established antioxidant activity, many phenolic compounds may exhibit significant antibacterial activity. Here, the effect of a large dataset of 35 polyphenols on the growth of 6 foodborne pathogenic or food-spoiling bacterial strains, three Gram-positive ones (Staphylococcus aureus, Bacillus subtilis, and Listeria monocytogenes) and three Gram-negative ones (Escherichia coli, Pseudomonas aeruginosa, and Salmonella Enteritidis), have been characterized. As expected, the effects of phenolic compounds were highly heterogeneous ranging from bacterial growth stimulation to antibacterial activity and depended on bacterial strains. The effect on bacterial growth of each of the polyphenols was expressed as relative Bacterial Load Difference (BLD) between a culture with and without (control) polyphenols at a 1 g L−1 concentration after 24 h incubation at 37°C. Reliable Quantitative Structure-Activity Relationship (QSAR) models were developed (regardless of polyphenol class or the mechanism of action involved) to predict BLD for E. coli, S. Enteritidis, S. aureus, and B. subtilis, unlike for L. monocytogenes and P. aeruginosa. L. monocytogenes was generally sensitive to polyphenols whereas P. aeruginosa was not. No satisfactory models predicting the BLD of P. aeruginosa and L. monocytogenes were obtained due to their specific and quite constant behavior toward polyphenols. The main descriptors involved in reliable QSAR models were the lipophilicity and the electronic and charge properties of the polyphenols. The models developed for the two Gram-negative bacteria (E. coli, S. Enteritidis) were comparable suggesting similar mechanisms of toxic action. This was not clearly observed for the two Gram-positive bacteria (S. aureus and B. subtilis). Interestingly, a preliminary evaluation by Microbial Adhesion To Solvents (MATS) measurements of surface properties of the two Gram-negative bacteria for which QSAR models were based on similar physico-chemical descriptors, revealed that MATS results were also quite similar. Moreover, the MATS results of the two Gram-positive bacterial strains S. aureus and B. subtilis for which QSARs were not based on similar physico-chemical descriptors also strongly differed. These observations suggest that the antibacterial activity of most of polyphenols likely depends on interactions between polyphenols and bacterial cells surface, although the surface properties of the bacterial strains should be further investigated with other techniques than MATS

Shotgun lipidomics and mass spectrometry imaging unveil diversity and dynamics in Gammarus fossarum lipid composition

Sentinel species are playing an indispensable role in monitoring environmental pollution in aquatic ecosystems. Many pollutants found in water prove to be endocrine disrupting chemicals that could cause disruptions in lipid homeostasis in aquatic species. A comprehensive profiling of the lipidome of these species is thus an essential step toward understanding the mechanism of toxicity induced by pollutants. Both the composition and spatial distribution of lipids in freshwater crustacean Gammarus fossarum were extensively examined herein. The baseline lipidome of gammarids of different sex and reproductive stages was established by high throughput shotgun lipidomics. Spatial lipid mapping by high resolution mass spectrometry imaging led to the discovery of sulfate-based lipids in hepato-pancreas and their accumulation in mature oocytes. A diverse and dynamic lipid composition in G. fossarum was uncovered, which deepens our understanding of the biochemical changes during development and which could serve as a reference for future ecotoxicological studies.Approches Protéomique et Lipidomique pour la compréhension des mécanismes moléculaires de toxicité en lien avec l'altération du métabolisme lipidique chez l'espèce sentinelle Gammarus fossarum durant le cycle de reproductio

Évolution des paysages et occupation humaine en mer d’Iroise (Finistère, Bretagne) du Néolithique à l’Âge du Bronze

Depuis près de dix ans, des recherches archéologiques sont menées dans l’archipel de Molène par une équipe pluridisciplinaire. Ce secteur s’avère particulièrement riche en vestiges du Néolithique et de l’Âge du Bronze. Une concentration exceptionnelle de monuments mégalithiques y a été mise en évidence. Plusieurs habitats sont attestés par la présence d’un bâtiment (Beg ar Loued, Molène) ou de dépotoirs domestiques riches en faune et en mobilier. Ces données nous renseignent sur la chronologie des occupations du secteur et nous permettent, pour la première fois en Bretagne, d’esquisser le mode de vie des hommes de la Préhistoire récente. Afin de pousser plus loin la réflexion, il nous a paru nécessaire de mieux comprendre l’évolution de l’environnement en contexte insulaire, par de nouvelles recherches sur les variations du niveau marin corrélées à l’étude du paysage végétal, de la géomorphologie et de la faune.Les résultats issus des reconstitutions paléogéographiques montrent que l’archipel était déjà constitué au Néolithique moyen II, déconnecté du continent par le chenal du Four dont la traversée nécessitait l’utilisation d’embarcations. Très bien conservés, les monuments mégalithiques de l’archipel sont donc le fait de populations insulaires ayant fréquentées l’archipel sur une longue période, débutant dès le milieu du ve et jalonnant les ive, iiive et iie millénaires avant J.-C. La répartition des sépultures mégalithiques reflète des stratégies d’implantations qui répondent à des choix culturels et à des contraintes naturelles, sur un territoire soumis à un morcellement progressif du fait des dynamiques érosives qui accompagnent la remontée du niveau marin. Durant tout le Néolithique et l’Âge du Bronze, l’isolement géographique n’a cessé de s’accroître, sans donner lieu pour autant à des particularismes culturels marqués, les innovations techniques et artistiques de cette époque ayant pénétré au sein des sociétés insulaires. Néanmoins, l’éloignement croissant des îles a encouragé la recherche de moyens de subsistance basés sur l’exploitation intense des ressources littorales, à travers la collecte de coquillages et de crustacés, la pratique de la pêche et de la chasse côtière. Tournées vers la mer, ces populations n’ont pas négligé les ressources qu’offraient les zones terrestres, comme en témoigne la précocité des pratiques agropastorales dans l’archipel.During almost ten years, an archaeological survey has been carried out in Molène Archipelago by a multidisciplinary team. The area appears to be particularly rich in Neolithic and Bronze Age remains and an exceptional concentration of megaliths has been brought to light. Several settlments are confirmed by dry-stone structures like in Beg ar Loued or by shell middens harbouring large quantities of bones and artefacts. These data give precious indications on the occupation chronology of the area. Moreover they allow for the first time in Brittany to reconstruct the everyday life during the late Prehistory. A prerequisite to this reconstruction was a better understanding of the environment evolution during this period, which locally implies a better knowledge of sea level fluctuations and its effects on landscapes as well as on vegetal and faunal resources.Results obtained via the paleogeographic reconstructions show that the archipelago during the Middle Neolithic II was already disconnected from the mainland by the Four channel which required boats to be crossed. Very well preserved, the megalithic monuments have therefore been erected and used by islanders being present on the archipelago for a long period time, starting from the middle of the Vth millenium BC, and spreading through the IV, III and IInd millenia. The distribution of the megalithic tombs reveals landscape occupation strategies which answer both cultural choices and natural constraints in a territory that undergoes a progressive fragmentation due to the dynamic of erosion linked to the rise of the sea level. Throughout the entire Neolithic and Bronze Age, geographic isolation has continued to increase, but in the meantime it did not imply specific cultural aspects, technical and artistic innovations having reached these island societies. Nevertheless, the increasing remoteness of the islands has fostered the search for livelihoods based on the intense exploitation of coastal ressources, through the gathering of seashells and shellfishes, fishing and coastal hunting. Although facing the sea, these people did not neglect what the land areas could offer as evidenced by the earl agro-pastoral practices in the archipelago

Vers un format unique pour le traitement des données

Institut de Chimie CNRS action convergenceNational audienc

La nécropole de tumulus de la « Forêt de Brumath (Sud) » : nouveaux ensembles funéraires hallstattiens (fouille LGV Est, Eckwersheim, Bas-Rhin)

National audienc

Controlled Release of Retinol in Cationic Co-Polymeric Nanoparticles for Topical Application

International audienc

FastPart: Over-Parameterized Stochastic Gradient Descent for Sparse optimisation on Measures

This paper presents a novel algorithm that leverages Stochastic Gradient Descent strategies in conjunction with Random Features to augment the scalability of Conic Particle Gradient Descent (CPGD) specifically tailored for solving sparse optimisation problems on measures. By formulating the CPGD steps within a variational framework, we provide rigorous mathematical proofs demonstrating the following key findings: (i) The total variation norms of the solution measures along the descent trajectory remain bounded, ensuring stability and preventing undesirable divergence; (ii) We establish a global convergence guarantee with a convergence rate of O(log(K)/ √ K) over K iterations, showcasing the efficiency and effectiveness of our algorithm, (iii) Additionally, we analyze and establish local control over the first-order condition discrepancy, contributing to a deeper understanding of the algorithm's behavior and reliability in practical applications