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High resolution and large field of view imaging using a stitching procedure coupled with distortion corrections
No full textInternational audienceA numerical approach was implemented to precisely stitch together images from the same projector/camera that form a mosaic by regularly moving either the projector/camera or the scene/sample. Such an imaging approach is used, for example, in automated microscopy. The presence of optical distortions can lead to detrimental blurring artifacts in the overlaps. The present development identifies and corrects non-affine distortion functions using the gray-level conservation equation on reduced overlapping regions of adjacent images with sub-pixel accuracy. The present numerical development was first tested on synthetic images with known distortions to confirm that the algorithm is capable of detecting only non-affine distortions. Then, Digital Image Correlation (DIC) was applied to a pair of large laser scanning confocal microscope mosaics (121 images of 1024 × 1024 pixel, i.e., more than 100 MPixel) created using the proposed non-rigid stitching. The method aims to improve the quality of blended images after stitching using the sample pattern in the overlapped regions. This new numerical development significantly minimizes kinematic field artifacts due to lens distortion in overlapped regions
How spray drying processing and solution composition can affect the mAbs stability in reconstituted solutions for subcutaneous injections. Part II: Exploring each protein stabilizer effect
No full textInternational audienceDespite extensive research in spray drying of biopharmaceuticals, identifying the optimal formulation composition and process conditions to minimize the various stresses a biopharmaceutical undergoes during this drying process. The current study extends previous research on investigating how spray drying processing and solution composition can affect the stability of monoclonal antibodies (mAbs) in reconstituted solutions for subcutaneous injections. The decoupling process stresses on a model mAb (mAb-A) compared to the effect of coupled spray-drying stresses revealed that excipients and protein concentration had a more pronounced effect on stabilizing mAb-A against shear and thermal/dehydration stresses than spray drying operating conditions. These results prompted the continuation of the study, with the aim to investigate in greater depth the effect of mAb-A concentration in the formulation designated to spray-drying and then the effect of type and the concentration of individual excipients (sugars, amino acids and surfactants). The outcomes of this investigation suggest that a general increase in the concentration of excipients, particularly surfactants, correlates with a reduction in aggregation and turbidity observed in the reconstituted spray-dried mAb-A powders. These results, contribute to the identification of a suitable composition for a spray-dried mAb-A powder that ensures robust stability of the protein in reconstituted solutions intended for subcutaneous injection. This valuable insight has important implications for advancing the development of pharmaceutical formulations with enhanced stability and efficacy
A generic hybrid method combining rules and machine learning to automate domain independent ontology population
No full textInternational audienceKnowledge management has become a cornerstone of decision support and system engineering. Knowledge acquisition has traditionally been performed manually, and the trend now is to automate knowledge extraction from the huge amount of information contained in daily produced data. This article proposes a contribution in the artificial intelligence domain through a hybrid approach for the discovery of concept-instance couples to populate an ontology. The proposed framework combines automated domain-independent rule-based extraction for unsupervised relation extraction and semantic-oriented machine learning techniques for knowledge base enrichment. In the engineering field, another contribution resides in the generic aspect of the framework, leading to the possibility to populate ontologies and automatically build knowledge bases in various domains. The case study supporting this framework and its technical implementation show that the proposed method can be applied identically (1) to different data sources and (2) with different ontologies, regardless of the domain or subdomain they describe or the structure they have. Changing these inputs can be done without affecting the performance of the rule-based extraction, which is around 60% in terms of precision. Three different matching methods are also presented. Their ability to match new instances to their corresponding ontological class (or concept) is evaluated through a case study on biochemistry annotated textual data. The best matching method achieves an average precision score of 70% and an average recall of 74%
Powder mixing in the production of food powders
No full textInternational audiencePowder mixing is one of the most common operations in industries related to powders. In the food industry, the main objective of mixing is to generate product homogeneity. The diverse characteristics of food powders mean that mixing is a complicated operation. Food powders can be of different sizes, easily segregate, be fragile, sticky, etc. The evaluation of powder mixture quality is a constant preoccupation to ensure precise control over process. Mixing quality is affected by the mixer type, mixer design, mixing time and powder types. Mixing practice for food applications is still based on a combination of practical knowledge and science. The quality and stability of mixtures depends on powder properties and mixing processes
An exact two-phase approach to re-optimize tours in home care planning
No full textInternational audienceWith the increase in demand, home care agencies must find efficient ways to schedule and route their staff. Unfortunately, the home care sector is never completely stable, the pool of patients constantly evolves, and the staff is subject to a high turnover. Therefore, home care agencies need to regularly update the schedules and to re-plan the visits of careworkers to patients. In this article, we present a method to re-assign the careworkers and re-design their tours whenever a schedule becomes obsolete due to the variations within the pool of patients or the staff. The originality of this work lies in the fact that we study the problem at the strategic level, with close-to-reality constraints. We analyze the impact of three different optimization criteria on the composition of the tours. We tested our algorithm on adapted instances from the literature and on instances extracted from real data provided by a home care agency in France, with up to 15 careworkers, 92 patients, and 337 visits over a week
Comparative Analysis of Ensemble-Based Nowcasting Models for Precipitation Prediction in the UAE
No full textInternational audienceAccurate and timely nowcasting is vital in safeguarding public property and ensuring people's safety, particularly in regions with infrequent but potentially hazardous rainfall events like the United Arab Emirates (UAE). The UAE experiences rare rainfall occurrences that can cause flooding, making it crucial to address these weather challenges. In this study, we compared the predictability of two widely used ensemble-based nowcasting systems, STEPS and LINDA, to assess their performance during various precipitation events in the UAE. Our ROC analysis showed that both systems have a commendable detection rate of over 0.70, a low false alarm rate of less than 0.2, and a substantial area under the curve exceeding 0.75%. Additionally, both algorithms demonstrated their ability to produce reliable nowcasts for up to two hours, using a 5 mm/h threshold. These findings highlight the potential of these models in mitigating the impacts of rare rainfall events, such as flooding, and emphasize the importance of investing in advanced nowcasting technologies for improved weather prediction and public safety
Navigating Unpredictability: Collaborative Networks in Non-linear Worlds: 25th IFIP WG 5.5 Working Conference on Virtual Enterprises, PRO-VE 2024, Albi, France, October 28–30, 2024, Proceedings, Part II
No full textInternational audienceThis two-volume set, IFIP AICT 726 and 727, constitutes the refereed proceedings of the 25th IFIP WG 5.5 Working Conference on Virtual Enterprise, PRO-VE 2024, held in Albi, France, during October 28–30, 2024.The 56 full papers presented in these two volumes were carefully reviewed and selected from 113 submissions. The papers presented in these two volumes are organized in the following topical sections:Part I: AI and collaboration; Human-machine collaboration; Emotions and collaborative networks; Collaborative ecosystems: Skills for resilient futures; Collaborative ecosystems: Technologies for resilient futures; Uncertainty and collaboration in supply chain; Collaborative networks as driver of innovation in organizations 5.0: Models; Collaborative networks as driver of innovation in organizations 5.0: Participation; Trust and trustworthy technologies in collaborative networks.Part II: Empowering vulnerable populations well-being through collaborative networks; Collaborative manufacturing systems in the digital era; Fostering collaborative and interoperable digital models for digital twins: Methods; Fostering collaborative and interoperable digital models for digital twins: Cases; Zero defects and zero waste strategies in industrial collaborative networks; Simulation frameworks; Collaborative decision making; Design of collaborative environments
L’étude de la déformation des matériaux par microscopie corrélative mécanique
No full textLa photomécanique est une activité forte de l’Institut Clément Ader. Elle permet de renseigner quantitativement comment les matériaux se déforment. Appliquée à la microscopie électronique à balayage et la caractérisation EBSD, le recalage et la fusion de données rendent possible l’identification de la plasticité cristalline
Desenvolvimento de sistemas liberação de fármaco a base de pululana para o tratamento do câncer (tese sob embargo)
No full textPullulan (PULL) is a polysaccharide produced by the fungus Aureobasidium Pullulans, which has been widely evaluated as a polymeric carrier for the development of drug delivery systems. The high amount of hydroxyl groups along its backbone makes pullulan easily modified, resulting in a polymer with interesting properties for pharmaceutical applications. In recent decades, many new therapeutic agents have emerged aiming for cancer treatment, among them, small molecules Tyrosine Kinase Inhibitor (smTKI). Erlotinib (ERL), a molecule belonging to the smTKI family has been proposed for oral chemotherapy as an alternative to the more invasive parenteral therapy. Due to the poor solubility in aqueous medium and low bioavailability of ERL, drug delivery systems are needed to enhance the efficacy of oral ERL chemotherapy. This thesis focuses on the preparation of cationic and cationic amphiphilic pullulans, and the use of these chemically modified pullulans for the development of ERL delivery systems aiming at oral administration and controlled drug release in the gastrointestinal tract. Two reactions were performed to chemically modify pullulan, first with Diethylaminoethyl (DEAE), for the preparation of cationic hydrophilic polysaccharide PULL-DEAE, followed by the copolymerization with poly(Z-L-lysine), using different proportion of the monomer, obtaining three cationic amphiphilic pullulan, PULL-DEAE-g-PZLL 25, 40 and 55%. The chemical modification was confirmed by chemical analysis, including NMR and FTIR. Zeta potential result demonstrated the cationic character of the chemically modified polysaccharide, while critical aggregation concentration showed the self-aggregation capacity of the final copolymer. After the synthesis, the polysaccharides were applied in the preparation of different drug delivery systems based on particulate solids: including solid dispersions by spray-drying (PULL:ERL and PULL-DEAE:ERL microparticles) and amorphous solid dispersion by hot-melt extrusion (PULL, PULL-DEAE and PULL-DEAE-g-PZLL ASD microparticles) and solid dispersion by dialysis nanoprecipitation (PULL-DEAE-g-PZLL nanoparticles). Each formulation was evaluated in terms of its drug delivery profile, using two different media to simulate the oral administration of ERL. First, the dissolution was performed in acid pH, simulating the stomach conditions, changing the pH to neutral conditions after two hours to mimic the passage from stomach to duodenum condition. The results demonstrated a controlled release from PULL:ERL and PULL-DEAE:ERL microparticles compared to free ERL in acidic conditions. For PULL, PULL-DEAE, and PULL-DEAE-g-PZLL ASD microparticles, containing 30% of ERL, besides the controlled release, the formulations also demonstrated an initial delay on ERL recrystallization in basic medium, keeping the same concentration after pH change for 5-15 minutes. PULL-DEAE-g-PZLL nanoparticles showed similar behavior to (Hot-Melt Extrusion) HME microparticles. The chemically modified pullulan has demonstrated a potential for encapsulation of chemotherapeutic drugs such as ERL, modifying the drug release in the simulated gastrointestinal environment.Le pullulane (PULL) est un polysaccharide produit par le champignon Aureobasidium Pullulans, largement exploité comme support polymérique pour le développement de systèmes d'administration de médicaments. Le grand nombre de groupes hydroxyles dans la chaîne du pullulane le rend facilement modifiable, permettant ainsi d'obtenir un polymère aux propriétés intéressantes pour les applications pharmaceutiques. Les dernières décennies, de nombreux nouveaux agents thérapeutiques sont apparus pour le traitement du cancer, notamment les petites molécules inhibitrices de tyrosine kinase (smTKI). L'erlotinib (ERL), un membre de la famille des smTKI, a été proposé pour la chimiothérapie orale comme alternative à la thérapie parentérale plus invasive. En raison de la faible solubilité aqueuse et de la mauvaise biodisponibilité de l'ERL, les systèmes d'administration de médicaments est nécessaire pour améliorer l'efficacité de la chimiothérapie orale avec l'ERL. Cette thèse porte sur la préparation de pullulane cationique et amphiphile cationique, et son utilisation pour le développement de systèmes d'administration d'ERL destinés à l'administration orale et à la libération contrôlée de médicaments dans le tractus gastro-intestinal. Deux réactions ont été effectuées pour modifier chimiquement le pullulane, d'abord avec la DEAE, pour la préparation du polysaccharide hydrophile cationique PULL-DEAE, puis par copolymérisation avec poly(Z-L-lysine), en utilisant différentes proportions du monomère, ce qui a permis d'obtenir trois pullulanes amphiphiles cationiques, PULL-DEAE-g-PZLL 25, 40 et 55%. La modification chimique a été confirmée par RMN et FTIR. Le potentiel zêta a démontré le caractère cationique du polysaccharide modifié, en même temps que la concentration critique d'agrégation a montré la capacité d'auto-agrégation du copolymère. Après la synthèse, les polysaccharides ont été utilisés pour la préparation de différents systèmes d'administration de médicaments basés sur les particules solides : dispersions solides par séchage par atomisation (microparticules de PULL et PULL-DEAE), dispersions solides amorphes par extrusion à chaud (microparticules de PULL, PULL-DEAE et PULL-DEAE-g-PZLL ASD) et dispersions solides par nanoprécipitation par dialyse (nanoparticules PULL-DEAE-g-PZLL). Chaque formulation a été évaluée en termes de profil de libération du médicament, en utilisant deux milieux différents pour simuler l'administration orale de l'ERL. Tout d'abord, la dissolution a été réalisée dans un pH acide, simulant les conditions de l'estomac, puis en changeant le pH à des conditions neutres après deux heures pour simuler le passage gastrique-intestinal. Les résultats ont démontré une libération contrôlée des microparticules PULL :ERL et PULL-DEAE :ERL par rapport à l'ERL libre dans des conditions acides. Pour les microparticules PULL, PULL-DEAE et PULL-DEAE-g-PZLL ASD, contenant 30% d'ERL, en plus d'une libération contrôlée, les formulations ont également montré un retard initial de la recristallisation de l'ERL en milieu basique. Les nanoparticules PULL-DEAE-g-PZLL ont montré un comportement similaire à celui des microparticules préparées par extrusion à chaud. Le pullulane chimiquement modifié a démontré un potentiel d'encapsulation de l'ERL, avec la modification de la libération du médicament dans l'environnement gastro-intestinal simulé.A pululana trata-se de um polissacarídeo produzido pelo fungo Aureobasidium Pullulans, que tem sido amplamente avaliado como um carreador polimérico para o desenvolvimento de sistemas de liberação de medicamentos. A grande quantidade de grupos hidroxila presentes ao longo de sua cadeia, faz com que a pululana seja facilmente modificada, resultando em um polímero com propriedades interessantes para aplicação farmacêutica. Nas últimas décadas, novos agentes terapêuticos foram desenvolvidos para o tratamento do câncer, entre eles, as moléculas pequenas inibidoras da tirosina quinase (smTKI). O erlotinibe (ERL), uma molécula pertencente à família smTKI, foi proposto para quimioterapia oral como uma alternativa à terapia parenteral mais invasiva. Devido à baixa solubilidade em meio aquoso e à baixa biodisponibilidade do ERL, são necessários sistemas de liberação de medicamentos para aumentar a eficácia da quimioterapia oral com ERL. Esta tese se concentra na preparação de pululana catiônicas anfifílica e hidrofílica e seu uso no desenvolvimento de sistemas de liberação de ERL visando à administração oral e à liberação controlada no trato gastrointestinal. Foram realizadas duas reações para modificar quimicamente a pululana, primeiro com DEAE, para a preparação do polissacarídeo hidrofílico catiônico PULL-DEAE, seguido pela copolimerização com poli(Z-L-lisina), usando diferentes proporções do monômero, obtendo três pululanas anfifílicas catiônicas, PULL-DEAE-g-PZLL 25, 40 e 55%. A modificação química foi confirmada por análise química, incluindo NMR e FTIR. O resultado do potencial zeta demonstrou o caráter catiônico do polissacarídeo quimicamente modificado, enquanto a concentração de agregação crítica mostrou a capacidade de autoagregação do copolímero final. Após a síntese, os polissacarídeos foram aplicados na preparação de diferentes sistemas de liberação de fármacos com base em sólidos particulados: incluindo dispersões sólidas por secagem por spray (micropartículas PULL:ERL e PULL-DEAE:ERL) e dispersão sólida amorfa por extrusão a quente (micropartículas PULL, PULL-DEAE e PULL-DEAE-g-PZLL ASD) e dispersão sólida por nanoprecipitação por diálise (nanopartículas PULL-DEAE-g-PZLL). Cada formulação foi avaliada em termos de seu perfil de liberação do fármaco, usando dois meios diferentes para simular a administração oral de ERL. Primeiro, a dissolução foi realizada em pH ácido, simulando as condições do estômago, alterando o pH para condições neutras após duas horas para simular a passagem gastro-intestinal. Os resultados demonstraram uma liberação controlada das micropartículas PULL:ERL e PULL-DEAE:ERL em comparação com a ERL livre em condições ácidas. Para as micropartículas produzidas por extrusão à quente (HME), PULL, PULL-DEAE e PULL-DEAE-g-PZLL ASD, contendo 30% de ERL, além da liberação controlada, as formulações também demonstraram um atraso inicial na recristalização do ERL em meio básico. As nanopartículas PULL-DEAE-g-PZLL apresentaram um comportamento semelhante ao das micropartículas produzidas por HME. Portanto, a pululana quimicamente modificada demonstrou potencial para encapsular a ERL, modificando a liberação do fármaco no ambiente gastrointestinal simulado
